CA2654463A1

CA2654463A1 - High speed surgical cutting instrument

Info

Publication number: CA2654463A1
Application number: CA002654463A
Authority: CA
Inventors: William C. Brunnett; Charles Stanislaus
Original assignee: Individual
Current assignee: Medtronic Xomed LLC
Priority date: 2006-05-31
Filing date: 2007-05-29
Publication date: 2007-12-13
Anticipated expiration: 2027-05-29
Also published as: US20140046329A1; WO2007143440A2; EP2032051B1; US20060241630A1; JP2009538711A; US9186157B2; WO2007143440A3; CA2654463C; US7879037B2; JP2013144203A; EP2032051A2; US20110106089A1; JP5714640B2; US8568415B2

Abstract

A surgical cutting instrument including an outer tube having a bearing sleeve disposed within a lumen thereof, along with an inner wire assembly extending through the outer tube and the bearing sleeve. A cutting tip is connected to the inner wire assembly distal the outer tube. Conversely, a coupling chuck is connected to a proximal section of the inner wire assembly, with a housing maintaining the outer tube and the coupling chuck. When mounted to a motor, the inner wire assembly is rotated to effectuate a surgical cutting procedure at the cutting tip, with the bearing sleeve supporting the inner wire assembly relative to the outer tube during rotation.

Description

EIIGM 4P-E11<M-[3 SU~llt#,FlCAL C'["TTCNG UNSTRUIf1lENl' BacUr0uiid 'I'lie present invention relates to a sLrrlgica.l cuttin;y instrument. More parcictÃlarfv, it relates to a high speed suÃ-4~;ir:,af cttttin4~ :iristr umenÃs, sucli as a fa(ariercutÃ:irig btrr, usable with various size or.ittirYg tips ar-rd adq'yted:f=or rtlirrir~aia.l interference witli surgical site visibility.

Surgical cutting irlstr urtierlts including a cutting tip are risuallv Corit~ected to a silotor-ized handpiec:e for rotating llie e:Galtiiig tip at various speeds to laerform a variety of surgical etfltt:rrig proce~.~tire>. Many liigli speed scrqg:rcal etitt:rrig iztstnsrnerit designs impair visibility, of a surgical site during a cutting' prorr?=edure. For example, high speed swIgica!
cutÃing irrstrurtlerrts otfert eri-rploy askraig;ht bur eYterte,ler including a ba111~e-arirlg assembly 6mve~,~r~ an oLÃ.t~,~r s7.rpport sleevÃ, aricl a rotating iriiier cutter shaft, Orrt.erdiaineters ofsr.rc:lr otater suppc3rt. sleeves r7.re r=clativel;r large (e.g., ~ii the order of 6 r~im) to accc3ttirrir.}date a ball bearing assembly. Suc1i relat:ively large outer diameÃers, create blind spots and otherwise impa:ir surgical site visibility- c1u_ririg c:utt:ing. Other linc-of=sight and har7tlling concerns are often encortntered dvith straight bur extenders. For example, tlie strai(yht srrpp(art sleeves associated witl-i straight bur c;xtericlers are typically in or rrcas- a surgeon's lirrc of siglit dtari ng cutti nty.

lnview of the above, it would be desirable #r:}r a srrq;ictal cutting iristrurlterit to 11~are a reclt.rced diamet~.~r and;/or arrgle or bend away from in associated harrciplecc to improv~.>
visrbiliiy, er:;onzsmics, or oÃ17er performance or c.ost.fi:rctors.
Arlditiorrk31ly, it would ~e desirable to provide a curved btt.Ã= extrvndrvr= operable at relatively high speeds wit.li s.rnaJl burs (e;.o., ~7.t~~:}t~t. 2 ttir~i) as well as larger l.r;; btrr~s 17~i~~ir~g cliartieter s~yreaier than about 2 mrn, :f=rom about 3 rtlrrr to abcaut 4 rrrn-a, car at least aborrt 3 n-anY).

Sunima.ry Sortie aspects in acLorrla7nLe witla principles of the present inventiczn r-el,ate to a surgical cutting ir-rst:runient for use with a motor having a drive riiec,liairism. The suÃ-gir:,af cutting iristr`uriierit iricltacles aD rrter trrbe,,a 1~~arir7g sleeve, an itiricr- x.0re as;;erribly, a cutting tip, a cotrplirrg chuck, and a-rousing. 'I'Fre outer tube defines a proximal region ÃerrYrirraÃ:irig at a. proxiÃnal etid, a distal t-cgioii terminating at a distal etid, arici a ltrrricri extending ft-orsi the protiinial erid to the distal errd, The bearing sleeve is substantially tubular in shape, a.ricl defines a proxiÃnal terminus, a distal t~,'Ã Ãl-iir-ius, and aii inner pass~,~;r;, At least a portioÃt crf the bearing sleeve is secLrrrkd wÃtli:rri the lumen of tltrk outer tube. 'l'l-w inrier v.Vire assembly defines a prcxximal section arid a distal section, fflid extericls tlirotigh tlic lr,imen of tlic outer tube arid throu~;,fr the i.r~.r-re.Ã=passa~;e of t(-re 1'_~earir-r~~, sleeve.
`I'l~e cutting tip is ~,c~r-rr~.ectecf tz~ tfre distal section of the inner wire asseriil.yly. Conversely, tlic. coupling ChLÃc1< is connected to the proximal section of the inner wire assembl4 ane1 is r7.dapte(l for connection to a drive mechanism of a motor. Finally, the hotÃsir-ig maintains th~,' pro\ima1 region.
oftlre otÃt~,'r ttÃbe and the c;otrplir7g chuck, asid is adapted for cor-inÃ?ct-ion tcx i motor.
With. this configuration, tlie bearing sleeve supports the inrier wire assembly upon rotation thereof relative to the (iuter t-ul;ae dt.rrii-i{,F a cutting c~peration. In some c;mbotiinierits, the ctrttii-i<,F tip 1-ias a relatively la,r4~e outer diniension (e.g;., on the order of at least 3 mm), with the bearing sleeve minimizing vibration ofthc cuttin9 tiR

Ot1icr- aspects in accordfflic~.~ with principles of the preselit ins,entiori relate to a ztretliod of performing a sur`gaca7.l rfr-i llarig pr-cx_edLrr-e on bodilv materia.l a7.t atar<.~et s.iEe of tlae patient. The z~iethod iztcludes paovÃdinga sr.iQg.ic.al c,r.rÃting ÃnstrÃrnteztÃ as described abc?ve.
Tlie bodily ruateria.l at the target site is exposed, arid the c;utt.ing tip is deployed agairist the bodily material. `I'l-re irrrler wire assenif?ly is rotatecf av it(-rin the outer tube atrcf the bearing s1cove to iriitsatc a cutting inlerface between the cutting tip and the bodily malen'al in contact tlaerewitf-.t. In this reoar~.~, fl-ae distal section of the Ãriner w:rre a.ssetztblv :rs maÃntaarre~.~
by the bearing sleeve, and the proxiz~ial secticyri of the inzter Nvire assembly is maintained by the outer tube during rotatic}n thereof. In sorne embodiments, the ir-mer wire assembly is rotated at speeds of at least about 50,000 RPM. In other embodiments, the niethocfolQ.;y is pe;rfr.}ri-iie;el as ptart. of anacoustic tie;ur~iiia srrr-ge;r-;r.

2 5 Bi=ief D~~cription of the Drawlitgs FIG. I is a cross-secÃional view of a surgical cutting instrument in accordance with prir-rciples of the preserrt invention.

FiCJ. 2 is aii explocled. c.rossrcsectiorlal view of the surgical cutting itrstrurrlerlt of F1G
l in an unassembled fQr=rn.

F1G'. 3A is a. perspective view of a1~eaci~ig sl~eve porii(ati of the cutting i~istrrimelit of FIG. 1.

Clf l. 3B i~ an er-icl viow ol`tl-ic. 1iearir-ig slcove of FIG. 3A, FIG. 4 is an enlarged cross-sectional view of the stirgic~l cuttYr-ig instrument crf_I-0ICs.
FIG. S is. a. sctieytiatic view illu4tratiyi`.,j, a method o.f'connecting art mner w:ire assembty to a coupling chr.ick ot-t:he surgical cutting imstruzneÃat of FIG.
I.

FIG. 6 is a cross-secÃional view of a surgical cutting instrument izi accordance with Principles of tlle preselrt iriverl'tiorl.

FIG. 7 is ~ii enltarored. cross--scctic3iital vi:~iv c.Yf the surgical ctxttinginstr'uarient of l:'l:G, F1G', 8 is a cross-sectional view of a surgical cuttiiig instrument in accoi-daiiee witlY
priticiples of the present izivezition.

FIG. 9A is c.ross-secti~nal view of a surgdc:..a:l cuttÃng, instrumeiit iii accordance ~.~ith priticipleti o.f't~~e present invent:iOal.

FIG. 9B is an erfla.rg;ed crossrsec;tiOrIeil ViCW Ot tlle 81.rr~;accil c~~ttirig i.r~~tr~.rr~~.~.r~t t~~
F:IG. 9A desi(niat:edby the circle 9B.

T)etailed Description Cmbocli.ments of liigli speed sm4~iCal CLattyrl4~ instruments in accordance with the '40 present inventim are to be miderstoocl curnulatively, as awhole, with features and Principles of operation treated inte.rclxang;eab1y as desired. With this M
axrincf, ~surgacal cutting instrument 20 in ac.cordanccwith principles of the pres~iit itlvetrtic~ii is showti in FlG, 1.. Tliesurgyical cuttyr~~,~ instrument m0 incltities taii otater suppc3il ttibe 22, a laearing sleeve 24, aiY itirler w.ire assembly 26; a cutt-iti~;tip 28, a coupling chuck 30, a tiousiiig 32, '~5 and ~i-i evaporative cooling sleeve 34. l:n general tems, the evaporative coolil-ig sleeve 34 is secured over a lort:ic}ii of the outer tube 22. The bea.Ã=ing sleeve~~4 is securedui t1ie outer t:ube 2" -wrth PorÃiogrs of ttle irlgrer wire aSserirblv .^t? coaxially dispoSecl wrtlrrrl the la~arrgrg slf~~~~,,e 24 ar-itl the outer tube ? ', reslaect.ivel.y.

The cutting tip 2.8 is c;oiiircc;tf>el to, and extciids diqa(ly frorri, tl~e, i.rrÃler Wire assenrbly 26, '1''1ic coupl.iÃ~g clrucl; 30 is secured to the izirrer wire asser11bly 26 a.ird is adapted for connection to a drive rriechaÃrism (rrot slrown) of a motor (not sl~o-vv~zr). "l'he housing _a.2 maintains the outer tube 22 -arrd the coripl"iii4~, chuck 30.
aiicl is a:lSo adajytetl :for coi111ect"1ot1 to a mL.>tf51'.

As will bc described in greater detail, some embocfimetiÃs irrc.ltide the ~earirrs; sleeve 2-4 maintaining a portion of the ii-iner wire a~semb(y 26 andjour-nai bearing being establÃsk~ed bet:weezr a por-ti(yzr of the iÃizier Nvire assembly 26 and the beafiÃag sleeve 2.4 Lipon rrotati~~i-i of the inner wire assembly 26 relative to the bearing sle~.~~ve .24. ;~~ourna1beas-ing is 'i1so optioJrally estafalisheÃl betweer7 a portion oftl~e outer tube 22 and t1ie inner wire asSerlihfy '26 u.pori rotation of the inner wire assc;mbly 26 relative to the outer tube 222. As described in greater" detail below, the instrument 20 taritf comporients tl7erecyfc}ptiotiaily provide on~.~ or more featLir-c;s that facilitate cxtr~,'niely high rotational speeds (c.g., iiiclLidsng at (east about. 50,000 RPM atrd on tl-.te order of about 80,000 RPM) ot'a re(ativc1y large cuttino; tip 28 in the form of a bur. including, for exaiirp:le bLir cut-tim);
tips lravirlg an outer di~iireter grr;aler than abc}trt. ? nrm-, fi omatrout :z mm toab ut 4 mar"i, r" at least taboul 3 111111, Adtlitic}naJly, t(-~e oriter tube ?2 arrd the i"rrne"rwire assembly 26 clekiiie orre or more crirved segrnc;sits as ciesired.

FIG. 2 i11uStrates the surgical cutting irrstrumerrt'0 in an unassembled state from an exploded, cre~ss-seetiorraJ view. With refererice t{) F1G:2, the outer tube 22 is 4UbsÃ:arrtizr.lly elongate and ttibular in shape. The outer tube 22 defizres a proxiÃxra.l end 40, a distal ezid 42, a proximal r~~w:iorr 44 terminating at the proximal end 40, and a distal reg;ion 46 terminating at the disml eiid 41 '1:'lre outer tul~e Z" also includes ati irrtemrediate region 48 ex-terrdirr5;bctwcc;n the proximal and diSfa( regiolis 44, 4& The outer tube 22 cfefilieS olie or more inner cifameters with a 1umex~ 50 emendÃrrg from the proxÃrrial end 40 to the distal end 42 at an inner surface 521 of tlic outer tube '222-I'lre outea ttil~e 227 assumes a variety of longitudinal shapes as, desÃred.
For exaznp1e, 3 0 the outer tube 222 optioma1ly defirreS a curved pr ofile at or along ~.~rre or botlr of the igrÃerrÃ-iediate regiorÃ 48 aÃid the distal region 46. lrÃ sorrÃe eixlfiorliixlerrts witlr a. curved or bent pÃ'ofile. the distal regicrrt 46 is atigGalttrly of~'set.fÃ-orrt the rrÃ'oxiÃ.rial Ã'egicirt 44. For example, the outer ÃLibe 2`2 exÃefrds t.lrrou+.õh a radius of curva.ttÃre from about 3 inches (abncÃt 76 mrÃ-a) to aboÃ.Ãt 6 ifliclies (about '1 5 '? nim), althotÃgli other climen siolis are coÃ-itemplated . In aclrlitiorl, the outer tube 22 is optionally constructed to iacil:itaÃ~
formation of a rotatirrgF
journal bearing 6.e., f'ricÃional slidirrg#otÃriral l.year~ing} relative to t.lrc. inÃzer wire. assembly 26 in,a straight corÃIigrtÃration or in corriurrctyc3ri witb a curved corrliguration.

'1'1ic frroxiarial region 44 of the otater tube 22 is adapted to be received ir7 the housing ..~s21. SoziÃe embodiments include the proximal region 44 being sÃ.ibstaÃatia.lly straight and uniform in outer diameter. For example, the outer diameter of tlÃ~.~ prcwima1 regioal 44 is about 0.090 inch (aboLÃt 2.3 mm), although otlter di:ÃrtertsiÃ~ns-, such as tapers or other features are also coriiernplaied.

The interme;cii,4r.te, region, 48 of the otÃter tulie 22 can form a.
shou.lcler 56 that abtrts the lÃ tÃsitig 32 upoti f~r7a7 as;;eÃirbly. Sor-ire; erribc3tlirrierri.s iricltade a re;rrrairitfer of'llÃe intermedi .~te region 48 extending clistal tlic hor7siflig 32 upoli finial assembly) at ia unitorm orater diameter of abriut [l. 1.10 iri~:~l-i (aborat.'?.79nÃÃrt}., .irÃclÃ.Ãdir~g, at a. cÃ.ÃrN~ed se.gmcnÃ 54 and oÃie or more sÃ.Ã=a i_ght seometÃÃs> if desired.

'I'he distal reg;ioÃ-Ã 46 optionally tapers in orÃter cl.iamet.er Ão the distal ericl 4-2. For exaÃarple, the otater tube 22 tapers from an outer ciitar-ireter of about 0.110 ir7c:lr (r7.b c}tit. 2.79 rÃim) to a diatixeter of about 0.72 inch (about l.8 _} Ãirr-~~) at ifie distal erlcl 42., although other dimensions are also acceptable. Alterttattvclyz the distal end 421 can be st7bstazitially free of aziv tapers.

TlÃe OLit:er tLibe ~~2 defines orÃe or rÃicare :iruier diameters alo:Ã7c, ttie luaxieri 50. Fcar example, the 1tÃniezi 50 is optionally detÃÃted fiv tAvcr or ziÃore 1eÃtt;Ãlts having different diaÃireters, In the c;c3rrfigt.Ãrat.ion of FIG. 2, the lun7erÃ 50 iarclt.Ãdes or is defined by a first seiwÃrÃerlt 60 having a first diameter and a secoArd seiwÃrÃerÃt 62 having a secoArd dianYeter.
~o-wcver, as wi(l. be cieseri.becl in greater detail, soÃii~,~ embodiments inc(rÃdc the lunr.eÃr. 50 var-yiÃig in diameter over three or ziaore segments if desÃred. Regardless, tlae first sqgrarent ~a0 oriaÃnat:es at the distal end 42 and extezids proximally along the disÃal region 46. The 3 0 secorid segatlerlt 62 exteÃ-Ãds proxirÃ-aal t'roatl the firsk segrrteÃtt 60 through a remainder of the outer tube 2~2 to the proximal er-ttl 40. 'i'he first segment 60, including the first diameter, is adapted to receive at. least. a portion oI't.he bettriiig sleeve 24, for example via a. press fil.. l:rl sortie ettibot.~ittierits, the first se+.õment 60 l-.tas a length in the razt+.õe c?:f'U.3 )5 --- 0.65 i~ich (abnctt 8.~-~ --- 16.5 mm), for exaniplt' 0.47 ir-icli (11.9 mm), and a cliwiit'ter in the ratige of 0.04 ---0.08 irtch (1.0 --- 2.0 mm), f='(ar rvxa.t~iple 0.06 incl-t (l. S mr-n); by way of reference, a diatiieter oi`-thc second segnzetzt 62 is in the range of 0.022 - 0.06 (0.51 - 1.5 mtii), for exaii-tple, 0.037 iric;li (f`3.94 mr-ii). Tt will be widerstooti, box.vever, that (itlier (iiarietisic~aIs 'are also t;otl tt'm.p1 att'cl.

Where the inner Avire assembly 216 is relatively small in outer dia.meter, the lumen 40 is relatively small in clianit.~ter. It shotrlfl be understood that redticiiia diameter size of t1lc ltt:Ãnen 50 tacilitates retluction of an overall oute.r diameter oi`the outer ttralae 22 while retaining sufficient wall ittical~i-ie;-ss k) lic;lp e;-asttre desired strength ai-icl rigiclity of tlitt otater t.tibe 22. As previously alluded to, redtacing the oÃrter cliaitiet.er I't.he outer tttbe 22 facilitates .~n ability- of'a st,iTeon or otlict- operatcxr to see :-t surgical ctittlng site during a t;.tti-tiri<.~ ope.ration. For exam la(e, portic>n s of the outer tube 22 extending clistal to the l~~Ttts:iDw 32 (inclttciing or exclttciing the shtit.tlder 56) def:.izte, in sotiie embodÃments, a maxi.mum outer di~iiit:.ter o.f r7o riic3re than abt.}ut. 0.1 25 inc1~ (ab ttt i.18 mm), altliotagli otlit:.r dittic;n;;ic3tis are contemplated. 1'he oLttrv.r tLtbe2'? is qytiortally cortstructed of aniatrvriaJ selected to provide the outcr tube ?'2, with liigli strengtt.h, liigli stiff'ricss characteristics wl-ii(e sattw-t~,,ing elÃttierisiotta.l and curvature constraints. For exa.riiple, tltc outer tttbe 22 is t'orttied of conventional sr.iQgical ittstrt.irneÃat materials, st.tch as stainless steel, 'I'lie inner sLirtarr=e 52 tif the outer tt.il~~ 21-2 can be highly polished to facilitate forniatiot-t of a.Ãot:a:tit-t~~ jott.rnal 1~earing subseqt:terttlv described in greater detail. More particttlarly, it lias surprisingly l.~eeii foxriid that polishing the iiiner starface 52 of t.lie ottter '~5 tttbc; 2'' to a st,ir~ace rottgbaess of tiot gt-c;wer than 201t inch, and i1-1 sonic embociimvtlts, not (;reater tliaai 10la. iÃaclt, facilitates viability of the surgical cuttitto instrument 20 incorporating tlic curvature .-tncl dimensional characteristics iat bigh operational sg~eecls. Howt.~~,~,er, other embodiments include the :Ãtuier surface 52 being relativety less polished or unpolished.

'1'he t~earit-tg s1~eve 24 carl l~e an elorigate, tubular body defining a proximal tertiliritts 64, a distal tei-ininu.s 66, ailci an iiirier passage 68 c;.xit?.ilciiilg frt}ri). the proximal tc;.rnliliÃts 64 to the distal terttiintrs 66. With this construction, the bc;aring sleeve 24 forms or provides a bearrng strr=farr=.e along the inner passage 68. Aclelitior-rally, the f?rw--arirlg sleeve 24 is ad-apted to be inserted i.nlo th~,~ outerlube ltrmeri 50 at thr,~ distal ciid 42, of the outer ttrbe 22) (es., witliin the first se(Sment 60 of the lumer~ 50). For example, t.he brkar ing>lee4:rk 24 is opts~na1k, sized to b~.~ press fit, or otherwise define an intcr-fcr-~,'nce fit, within the otiter tÃibe 1u.rnen,50 at the disui1 erid 42. 1'he in.r-re.Ã= passage 68 is sliowtr g;enezafly as exaer-rtlir-r(j for a sxrb sÃant-ially continuous diameter; however, it sliorrld be rrrzderstood that other featrrres, for ~xarnple stepped e1.ian-ieter's or (itlier selected variati ns in the iririer Pas:~age d.iariieter, are atso t:ontempliatecl..

'1"lae liearizio sleeve 24 is sr.ibstantÃallv cylindrical and circular in transverse cross-section, thor7gh. other shapes, such as ellipsoid, for exasiiple, are also contemplated. In soiii~.~
embodimertts. the ~earin g sl~~~~e '24 has a len4,h an the range of aboLÃt 025 ~ 0.65 inch (ah(arai 6.35 - 16.5 mrn), for esasaiple, 0.46 inch (1.1.7 rnin); a.sid ari iiii-ie;-r cl.iar~tieter in tlic r`arige of ab rrt 0.02 0.06 lr7c.h Ã0.: 1--- t.S mrii}, for extar-iiple 0.0:38 iricl7 (0.97 mrni);
although other dimensions iare coiit~,'niplat~,'ci. An outer rliianietcr- of the beariiig sleeve 24 u3ri be sized iD ac.Lo.rda.nee X.Ylt(r the otiter tr.rbe l.urraen 50 (e.4.~.., zrt or along the first segment 60) so as to faeiliÃate a.press fat or interference fit. in this re;yard, and with reference to f:IGS. :i ~~iicf 33113, the bearing sleeve 24 cari include a pltirtality of lorigit-irtiirial ribs 69,a prqj~ecÃ:irig from an exterior surface 69b. '1'he ribs 69a cornf?:irie to delrrre an effective outer diaÃneter approxiniviÃlg or slightly largcr than the corresponding dianieter of llie. otiter tube luntert 50 (FIG. 2), fc?:r example in the :rarige of 0_041 --- 0.081 i~ich (1,04 --- 21.06 Ã-aim), and caai be 0.061 inch (1.55 mm')_ 'I'lie bearing sleeN=e 24 otiter diameter at the exterior surface 69b is slightly less t:haii the ekTective otiter diameter defanecl by the r-ibs 69a {e.o,., on the order of 0.001 --- 0.0l ii7C17 (4).025 - 0.225 Yllm) lesS}. 'T11e cirGurnfereÃ1tial spac1i1g be;twc:eri the ribs 69a facilitates ease cyf press-fit assen-ibl4 ir7to the outer tube Iun7er7 50 as ?5 the ribs ~a9a can ziiore easily deform to aecair.rÃat for tolerance varÃatÃons. '1"-1ie ease of szsscrlibly can be fu.rtlicr er-ihar-iced by the ribs 69a terminating distal the prcrzimal t~.~rn-rir-ir.rs 64 (t17.at is- oÃherwisse initially inserted into the outer tube lumen 50 duririg as-sembly).
Ttir-tlier, tipon iiial as.embly, a sliglit air gap is established betweeii the ii~iier starf'ace:?m (FIG. .2) of the otiter ttabe 22 tarid the exterior srrrf~ce 69b oftlie bear-irtg sleeve ?4, witli t.lii;;
air gap assisting in. cooling during rrse. Alternatively, the ribs 69a car-i be clirliir-iat:c;d.
The beariiig slee~,~e 24 car-i be formed from. a var-i~,~tv of materiials compatible with hi4;1~ :~f~~:.~:~1 rcita~tyc~ri of tl~~:, iri.r~~:r~ ~~ir~. a.~;s~:.r~~rl~ly 2(>, s~:~lc;~:t~;~l i~c~ c~.l~it~ii low wear arrcf lciev Is t:err-iperaÃure characteristics in the presence of the rotating wire asserrrbly 26, 'I'o this ~~id, a material of the beariiig sleeve 24 is, in som~,~ embodiments, selected fo be a lcrw wear zr-aaÃej`:~al that ~~~ill not generate adverse ciebrts (e.{~.; black Ãrr color) whert subjected to a high speed rotation of tlic otheRvise metallic inner wire assembtY 1.6, and t11tÃs is in ~~~-ie ezrlbodizrlerlt :f=ormecl from a niaterial other th-an tiietal. For exazrple, tlie bearing, sleeve 24 is for~~ed of a material iirc.il.ading one or more of the following:
polyeÃlzereth cr.l<etone (f'EEK);
PEEK witlr carbon adclityires. PEEK' witb polytetrafluoroethylene (P'I`l-"E) and carb ar acfffstives; fgT-FE, iaicltrdiiig T'T-FE with various aclditiv~,~s', coraniics, su.clr. as sappbirc;, for example. Tn other oniboflimÃ?i-its, the ficaring sl:eeve 24 can be fi:xrmcd of a sur(-ically-sa fe metal.

ftetatrruJig to FIG. 2, the inner wire assenibly 26 izic.lud~s a proximal secti(an 70, a (listal soctii.~i-i T2, asid ari isitorr-riecliate section 74, the itrtermediaie sc;c~.tioi~i 74 l;aeti-vocti the proximal section 70 arrei the distal section 72. fD s~iire eiirbocfiiirer7ts, the in.ner wi.re assembly 26 has an overall longitudinal length grciater th~i-i that of the outer tube 22 stÃch tlral UpOri firla.l zisserribly, the proximal arrci distal sections 70, 7~~?.
extend from the prc>xir~tal and distal ends 40, 42, respectively, of the outer tube .12 -'I'he proNitiiat secÃ:iorr 70 is (,enezaf 1y adapted to be cc}rirrected to the coupling ctlrick :>fl,,as will be subsetltieritly eiescribed irr greater det.ail. 1II t-tirar, the distal section 72 is adapted to l~~ corirlected t:otl~e cttt-ting tip 28, as will also l~e described in greater cfetail. '1'lre inif.nnediafe ~eclYoii 74 is gerif.rally adaptc;ci to provide a flexible, mechaiiical coiiiieclYoli betweezi the prÃ7.-maxial and distal sectiÃ7.rrs, 70, 72 such that rcatataori of the proxarrr.al section 70 translates to rotation of the distal section 72, and tlius, the cr.ittino tip 'S. Some embodiments include forming the irlternrecl:iate section 74 to defirie a length at least as lorig as ati extension oftlie c.un-eci sect-ion 5=1 of t.lle outer tul.~~.12. For cxainple, tlie itiÃer-inediatc ~ section 74 is optionally formed to hav~,~ a. ma~-~sii~ at c~t~:h end, sti~.l~ that the interni~ydi~at~~
section 74 is somewhat longer tliaÃt the curved sectioÃt 54 cYr cun=ed sections w`liere, appropriate. Su.cb ``(-)~,,er sizing" of the intermediat~,~ section 74 optionally liclps c;nsure that the inner wire assetnblv,26 does not bi:Ãrd Nvitl7 ttie outer tube 22, for example.

As pr eviotÃsly aI ltitletl to, the iritertrieeliake secki~.~ri 74 c.ari be rr-aore flexible tl~~ii at least one of'tlr.e; pro-xir1ia1 sec:.tioli 70 and the distal sec:.tioli 72.
For example, the inte;rinc;.diate ;;ectior7 74 opt.ionall y dc;.fiares a ;;ubstar7tyally smaller dUcurieter t1iaii one or both of tlie protiirrial secÃiori 70 ar-rd the distal secÃiori 72 in order to provide relaÃively r7r(are f'Iexibility to the interÃnediate section 74, for examp1~,'. The diameter of the ir.ÃteÃinediide -wclYoii 70 caii be selectecl to be sÃiÃalleÃ- thart that of the pÃ-oxÃÃn al ser:,tion 70 arÃd the d:rstal ser:,tion 72, in pat-t, bc;c;aus~.~ the int:c;rrl~ediat~,~ section 74 does liot support beiidiiig loads iÃ-icfÃ.ac:ec~ by the cuÃtino, tip 28 to the same rv-xterrt as the distal secti(arÃ 72.
Adcl:itiorrallv., or aIÃerna.tively, the int.errnedÃate. section 74 is formed ofmÃ.~re flexible materials than Ã.~ric or both of t.lle proximal sectior~ 0arÃei the (listtal sectiori 72 or iric;ludc;s otlÃer fi;:aixÃres to prc3rtic3t:e f1~,'xibility. By way ofiioar-limiting e\amples, the cliamcter of the proximal fflid flsstal sections 70, 7211 is in th~.~ range of about 0,025 ---- 0.045 inch (0.635 - 'l .14 mm), fi.xr example 0.035 inch (0.89 rnm); whereas the diameter of the intermediate section 74 cal7 be an tlle range ofaborÃt 0.015 -- 0.0:35 inch (0.38 --- 0.89 rnÃaÃ), for exarr-iple;-0.024 iÃic1i (0.61 rnÃaÃ), it beiÃii) understood tl-rat: a varieÃy or other dirÃiensic}r~s are also contemplated. For ~xarrlple, in alternative embodiments, the inner wire asserÃibly 26 has a usiif'orm diameter.

The innc;r c~~ire assembly 26 is optionally adapted to facilitat~,~
establisbment of ia zcitai1ing:jou.rrra7l 1~earirÃw relative to the (iuter tube 22 zrrÃd the 1:~earirig s1~eve 2 -4. Iri sorr.-te embodiments, the addÃtiona1 f'lexibÃlitv of the intermedia:te section 74 facilitates rotation of the irrtermetfiat.c; section 74 witlÃiri the outer tube22,at the curvedsc;ction 54. :l+or e;xarriple, flexibility of the irrterÃiiecl:iate serr.tioÃi 74 1Ãas the poterltial to reduce fa:tig;ue effects on the inner wire awserriblNr 26. biridirig of the inner wir-e asseisibly 26 wilhiri the outcr fÃ.ibe 2?, for exarÃiple pÃ-oxÃnÃa.te the curved segment 54, anel./or overall resistance to rotaticarÃ of the inrier ,v~ire asseml}l~j ?~ ~~~1~Ãle iri a bent cc~x~tÃ~;urat:aon, A
relative1~71ar~;er diatÃ~eterz and Ãl~eaefE~re rigidity, of the proNitrial secÃ.iori 70 optiomai1ly provides adtlit:ic}riaJ
structural support f(ar oorlriection to the c~.~Ã.rpling c.11LÃc1< 30, as well as a more stable j~.~Ã.rrnal bearÃÃZg witliiri the otater tube 22. AclditiorÃally, a relative14 larger diameter cyl the distal sec.tion 72 provides ?5 additional staLrr tura.l sÃÃpport for tlÃe cutting tip 28 (e.g,, when sul~jected to beÃirlÃÃi(; lc~ads szlici,r'cÃr irlipact chatter loacls flu.riiig e.Ã.attiiig), as weIl as a niore stafrlejorÃrnal bearing within the bear`ing sleeve 24 as desired.

Diametric clearances bet-ween the outer tLafae 1LÃmen 50 and tlie inner wire ascen7bty 26, and bearing sleeve inner passage 68 ~~l(i the inner wire asserlihlw '26, are optionally >0 selected to prorÃ-ic3t.e; r`etftÃcecl potential t:cx-binclingat7tf establishrtie;nt c.Yfe;fTedirejc3t.Ãrr7a7 beariiigs. For emimple, the outer diarnc;ter of the proximat section 70 of the inncr c~~ir~,~
assembly 26 Lair be aboui. 0.004 - 0.005 inch (0.025 - 0.1.27 rrurr}, for example 0.002- aricli (0.05 r7rrr-i) less Ã:h-arr t(ie diameter ot ttle secorrd seg;firent 62 of the outer tube 1trrr-i~~~ 50. In ttrrrr, the otrt~,~Ã' tliasiletcr of tl~c. cilstal -wclYori 72 of the inner wire iassernbly 2.6 ewi b~,~ about-0.0U1 --- 0.005 irrcl~ (0.01-5 --- 0. 127 mm), for example 0.002 Ãrrclr (0.05 mm); le>s, than the drianiet:c;r of the inner piassage 68 of the bearing slc~,'~,`c 2'4.
C~~~~vers~.'1y, the otÃt~,'r dianieter of 5 the interrYÃediate sectic}ri 74 caii be about 0.005 --- 0.[}2 5 inch (0.12' --- 0.635 rr-rm), for exainple. 0.0 13 inch (03 3 nznr), less than the diameter of the sec.ond segnzcrzt 62 of t.lre otiter ttrbe luarieri 50, t:or exarirple, l:t will be trri(lcrstooe1, however, that oil7er` c.lin7c.r7sions are also con temp1 atccl.

As alltiderl to a1~oN.=e, the inner wire assembly 26 is generally torÃxred to exhibit high 10 strength and good tatigLi~.~ cbarac;teirstsc;s. Fatigue strength is a ft7siction of material sel~.~c:tiorr.
and end 4?eometJy.., as w=e:ll as otl7er'varÃables. In s-ome emfiotl:Ãments-, the .iruier wire assembly 26 i::f-briarecf to exkribit Ai fatigue stre;-sr.gt:h or endurance limit of at leasi al;aotrt 7-5 Kpsi w-liere the otrter t.tabe~~'2 i1,11pa.rts a curve arto a longitudinal length of the iririer lVire assembly 26. It has stiÃprisinglt becrr. found thiat such f'atigr,ie strc;ngtfl cliaracten'stics ianc1 dimerrs:ions zr.re optionally achieved with ari a.pfarczlzria7.i.e tool steel rna7ter-ia(., sucla zr~ _N.4,-sefles tool st:eels tÃxrolybdenum high speed tool steels'l, A-series tool steels (niedÃuzir-alloy aira }rarderiin,~4 co.ld wo.rk tool steels), and Otl7er`s.

For exanrple, the iarrrer wire asserribl4 26 ctari be a 1101170gerrOtaS, Orre--piece Wir-e M2 tool steel. Alternative other iira:terials extrilait:irig the desired durability and fracture rc;sistance are employed for tl-ic.. irirrf.r x0re assembly 26, iÃlc.ltrclir-ig, for e~anrple, otller` tool steels; 304V luglr tensile streng:,tfi drawn vvire, other steel wire rrtatera{rls subjecteci to a roll burrrislrizrg process that improves the fatigue strength of the Avire by putting the otiter surface into a state of compression; other steel wire rr-raterials sul~ject:ed to riltrasc}riic shot peenirig or laser shot peerrirrs; fbFr irirproN=ing fatigue sÃreirgotlr of the wir'e by putting Ãl1e, outer '~5 surface intoa stat~,~ of corlipr-ession; and others. Everr. fiÃrthc;r, in soiii~,~ cmbodirlients other zionasteel zneÃals such as iridium, osmium, or ruthenium are optiozially eÃxrployed, as are ceramics sLiclr as silicon carbide, silicon nitride, boron carbide, titanium carbide, t~~ngstotr.
caftiide, and crtlrers. Conventional .ÃrrateriaJs t`liat do not crtherw:Ãse conform to the alicrve-clewcribe;c1 strength and stsf fncss pararlicters can also fie employ-ecl.

To tr,irther enhance wear resistaric:e properties t}f the inner wire asse,mt?l.y "6, the iarrrer wire assembl4 26 ctari be suÃ~jject.e;d to prc3c;c;ssirrg (e.g., lre~at treatetl) MI/Or coated witlr 1f additional material (s): resulting in a Rockevel lHardÃ-Ãess of 3iot less ffiari 50 HRC; or Ãiot less tl-iaÃi about 60 ;l-iiRC'K for ex-aÃliple, although other characteristic R.ocko~-vl( Flardnews values are a1>o contemplated. Sotztc embodiments iriclrlde employ-irig a harcterÃe~.~
material (not slÃo-waij coating to pro-vide a cleaisc carbon finish to the inner wir~,~
ass~,'nibly 26. For example, t(-re lÃarderled material coa.t:iÃi4~, carÃ l~e a dense c:arbc}ri (cfiamoÃ-rtl-li~e coatirlg).
coated to a thickness of not inorc than aborÃt 03 mnz , although other dÃÃiiciisi~.~Ãis are cc3titetn plated. Other cotat.ing materials are also optionally employed, stÃcb as, .for exarÃ-iple;, zirconiÃ,Ãm. rlitride, chrome, po1yt:c;trafluoroethylonc (PTFE) or other f1tÃorocarboÃi materials, titanium nitride, electroless nickel impregnated with PTl~'F, iira(l tathers.

The cutting tip218 cEin assume a. variety of forms and generally includes a.
cutting bÃ.Ãr 76 and an attachment er7tl 78 adapted for connection to the distal section 72 of the :Ãruie,- wire assembly 26. The attAiclirrieÃit ~i-icl 78 can be configured to coaxially Ã-ee::eive; the distal section 72 I't.he irarier vare assembly m6. Regardless, the inner wire a;;ser7ibly 26 is can be connected to attachment ond 78 via a liÃ,Ãmber of known processes such as, for example, laser welding, br:Ãz i4~. press [ittiz~4~, thermal slir-iril< #iitiÃ~.4.~, adlie:~a~:=e, aticl others.
AlterÃiatavely, Ãlie attachment eztd 78 of the inzier wire assembly 26 and the cutt:itÃg tip 28 can be coÃiriected by ir7tegrtally forming the disAal section 72 of the irarier wire assen7laly 2`6 aricf the ctitÃirlg tip 28 (see, e.g., cuttirig iristruzrlerit 120 of F:1G 5).
For ex-arÃiple, the iÃ-rner wire assembly 26 and the cutfYno., tip 28 are. optionally machirieel tt-otsi a sing1c piece of stoc.k.
material. The crfltt'Irtg bcÃr` 76 optionally tleti:rtes an outer cliatiieteÃ' of greater thartabc?ut 2 ziiÃxi, an orÃter diameter front about 3 ziiÃxi to about 4 nun, or an outer diaÃxieter of aborÃt ;') mzn or rixore, for example, although other diÃiierisioÃis are corrtempla:ted. :(n particular, the otÃtÃiÃig brÃÃ' 76 opti~.~iiall4 assumes a variety of shapes and sizes knowÃZ
in tlie aÃ-C (e.g., 3 rÃZm fluted, 4 rtir-ii ditartiorit~ aDd t}Ãers)=

'~5 The coupling chtÃck 30 is generally colifigtired to facilitate eonrlc;c:tion. of the motor drive mechanism (zic?t sliowtÃ) to tfaeinner Avire assembly 26. As a point of refereÃac,e, each of the motor (ilot sbown) aÃ-icl the clrive mechanism assÃ,Ãm.es a. variety of forms as desired.
For example, the motor is (Yptionalty of a type typically en7ployetl with surgical cutfiang inwtru.merlts, sÃ.ach as e;lectrie, batte;ry, powered or pneÃ,Ãnmtlc:. Also, anv otlier type; of motor >0 or drill drive system is erÃiplc3yect as desired. Similarly, the drive r-iic;cl7ar7ism is optionally of a type typically employc;cl c\.-ith surgical ctÃtttng iflistrGar~ieÃ-its that facilitate cotinec:t.ioxÃ or c;oÃalzlin- to the c;rat.i~itig device, srac;b as mechanical c:orinec:Ã.ic>xÃ., a tiorÃ-Cot7t:aCtit7.F~f, Il"la}?;T1C'.ttG connection, a tlt?tircClTltr`7.Ctltig air drtvetl coupling {e.&, an air Valle}, ai'#d ofliers. With tl-iis in riii~id, tl~c. coupling cliu.ck 330 is adapted tc}r use W7th a nlecliarlicial-type drive mechanisra, it beiÃ~g uriderstnorl tltat tltc coupl.iÃ~g c}~uck 30 is can be cnrit:tgured in ac:corclance with any other ty-pe of cfrive mec1~anism..

~ The corÃpliÃag chuck 30 ~efiztes a proxiznal end 80, a dista.l end 822; a proxintat portion 84 extending to the prc}xinial ~iicl 80, ~~~d a distal pc}rtiorl 86 extending to the distal end 82. T.11e distal ponioiz 86 forms a first passage 88 originatiji.; at the clistal encl. 82, 'I"he first passage 88 is sized to r`ecc;ive the pr'oxir-rial sect.iotl 70 oI'the;
iririer lvyre assembly 26.
'I'he proxiz~ial portion 84 can further forin aseconci passkRe 90 extending proximally tront th~.~ first passage 88 to the pr(-)\im.al caici 80. Th~.~ secc~i-icl passag~.~
90 is sized to cotzxially receive and maintain the proximal sect.itaJl 70 oi`the inner wire assembly ?t"~. Alternatively, (see, e.g., surgical ctrttii~ig instrument 320 ol.FIG. 8.~)-, the secorlci passage 90 cari terminate distal the proxin7a1 eaiel 80 uf the coupling chuck 30 as a closed, blind hole.

Some embod.iaiierrts iticlutfe the proxir7ital portion 84 forming a groove 92 ariei a tang 94 each adapted to tacilitate c:o-uplin;~; to the cfr-ill motor drive sl~aft (n(-)t sh(jwn). The tang 94 is oI'a r'ecluced diameter, axid serves as a wuide srr.r.{~ce that promotes rapid, consistent asser-rlaly of the drive r~~echarusin to the coupling chLic1;: 30. However, the couplirig chuck :>fl assÃ$Eiiie a variety of other c"or7figrrnations, aaid taswn7taly cA the coupling chuck 30 to the outer tube 22 arid.'o.Ã= tfie innerwi"re a.ssernbly"26 is a1so optionally varied as desired. For oxaÃliple.. the coupling e.llucli ~~ can bf.an iiit~;_LYralllr form eci part of tl-ie, inÃler XV`ire IR:sernbly:
2fi.

Sinularlv to the coupl:izr~ chuck 30, tlie housin4.~ 12) can assta:~~ie zi variety of forms and is generally configured to support the outer tu~e,221 as well as tacilitate conziectioÃi of the c,c}uplirlg chuck 30, arid tFius the inne"r.:vire assernbly"'6, to a zrlotca"r (not shown). '~Me housiny.~ 32 ean:f=ornY a central aperture 100 having aiY opeii proxin-aal eiid lt.}?. 'I'lYe central ap~,~Ã-tÃire 100 is sized to receive at least a portion of the motor. The housing 32) is configured to facilitate attachment to the drill znotor via snap tit; threads, interterence fit, and ot:}iers.
The hotÃsii-ig 3.2 defines a passage 106 fitaicllv coiiiiected to the aperture "1 00. The passage 106 is sized to maintain the otÃter ttÃbe 2'2, and catt be tt.irti-~ed drÃr i~ig ari iiiserÃ rii~.~ldiit.~
pror:eci~irc; or otherwise. For examplc, the hottsing 32 is optionally insert molcleci over the otater" t.tabe 22. Also, a variety o.f other assenibly tec;liriicl~ies fc3r connecting the c3ut"er tt~be 22 arirl the liousirlg ?2 ca:ri lae ernpIt:~~~ed, suc1i as oIuir-rw, welclirrg, press-fitting, Ã:herr7ral shrink fit.tirw> and o1liers, l:ti soÃne ernbociirnen.ts, tl~~~ evaporative cooliiig sleeve 34 (FIG. 1) is larovicieci and is-seccrred or formed over azi exterÃor of tl-.te outer tube 2)? azi~.~ extends from the proxirnal fl~e C, }tc?usizi;y :~2 to the distal region 46. The cooling stee~=e 34 is forrne~i of a ~r~.rÃetv of ma.teraals, for example fabric rrlate.r=iaJ sLrch as rivlori, silk, pol;
propylerre, lx}lyester, cott:on, -ind otliers. In panieLÃ.lar, the cooling sleeve 34 is optionally uncoated rivlon. Regardless, the coolir~~,~ sleeve 34 cari readily confc3rn-i to any curved segrrictit(s) defiiied by the outer' tube w?_ For example, the conlin~y sleeve 34 is cnrtstruct:ed as a braided tiibe or a coil of thrc;acl woL7sid cllrectl~~ onto the outer tr.it~e 2.. Th~.~ co~xlir~9 sleeve 34 isc~ptior~.~11~~ secured o-,.,er the outer tul~~.12 via a variety ofmeans. For example, opposartg ends oftl~e cooling sleeve 34 are secured to the otator t:tabe;- 22 by calarr-ipir~ig or aclhosivo as e.te;;ired. T}ic coolirig sleeve _3~4 is geiier-ally COD;;tructecf tr.} absorb flu.icfs (e,g_ bodily fltricls at a surgical sit.c., irr-lgatiori. fluids delivered dr.aring a surgical pr=occfltÃr=e, and others) ar-icl in operation wicks a.bsorbed flriids toward the hczr.rs.irr:; ;'. l:ri cithe.r words, flrr:ids absorbed by the cooliti~
sleeve 34, fc?r e ~aÃa~l~l~. prc~~.iniate the distal end 4~. of the outer tube ?~, are coÃtducÃed proximally by the cc3oling sleeve :'14 toward the proximal region 44 cA the otrter t-ltbe 2.2 until a subst:-antial portiori o.r arl enÃirety of the coc}liri~~. sleeve 3 N is saturated. While the coolirlg s1cove :'14 is showrt iti FIG. 1a, ex-1ending :dor~g a substantial leriglh of the outer ttibe ?'?, tltt;
cooling sleeve 34 need ric?t exÃerid to the 1-mr.ising32. 1; LtrClter, the rr.oolirig sleeve 34 can be cortstrÃrcted and sized to ertcnrnpass an ezlÃÃret-y rif the outer tr.rl~~ 22 2.

Dtrring use, fltrids absorbed by the coolizi;y sleeve 34 evaporate via heat generated by rotation of t(-re irrrler wire asseml?1y 26 (FIG. 1) relative to the oLrte.Ã=
tLrbe2'?. serving to cool the outer tube 22. Witli this construction, as the olater tr.rbe 22 conducts more heat, the '' s c~.~~~r~ati~~~~ g~r-oc~,'ss fae.ilitatcf3 by the ~:~ar~liri~~ slc~,~'s~e :~4 becomes more ~tggr~,'ssi~~e.
regulating a sur-tace ternperature of the outer tube 22. to a relatively consistent 1evel, for exar-npl~,'. ln operation, it has been sr.arpr-isingly found that regarclless of a tempcr- .~ture of the outer tube 22, the cooling sleeve 34 serves to cool tl~~ outer tube 22 to a stitistantiaJly nominat temperature t.-vvithin 10' C). in tlle pre;sence; of t~ulciw.
.k.et;arclless, ari e;nhanc;e(i >0 coolir~g ef~ect is provided iti co~t~junction X.Vit.h fluids proximate the surgical site, Alternatively, lro-wcyc;r, th~,~ cooling sleeve 34 cari.b~.~ climinated.

With respect to asseiiil?1N, of the outer tube ?2 aiicl the inner avire assembl? ?t>. a.
lubr-icant (not sliown.) is opiionally provici~,'ci M the otÃt~,~r ttÃbe lun-icn. 50 alor-ig a length of aii.
interfa.ce betweefi tl-.te intier v.Vire assembly 26 azi~.~ tli e outer ttibe "'?. '1'I-te lu brieant can ~ac.ilitatc formation of a I~~droclynamic,jourria1 la~,~arilig between the outer tubc; ?`' and the inner wire assenibly 26. :1:11 p-articul-ar, the .iiiiier wire assembly -ti is supported by a hydrod~~~iainiceffccÃ and etTeetively "floats" relative to tlic. outer tube 22 ttpon rotation of the irii7er' x.6re as;;ernb1y~'fi as cle:~irec.l. Lubricant is also optionally disposed in the bearii7g 4lt t S'f' inner piis4as;E; 68 along ia length of an interface bt,tLvE;t;13 the 131r#'.r wire ii~se1~~~~ ~6 and the la~.~ariaig sleev~.~ 214 to provi(ie a substantially <inii1ar hyc1rodyr7szanic effect l;icts:%c~.'n tlie bearing sleeve 24 and the it~.ner wire asse:Ãttl~l~~ 26 ~.~ desired.

With this in mittd, the lubricant can be a grease Iu~~cant, rlThe lubricant can exItibit a dv~riaaiiic viscosity o:f"at least about 100nini2 /s at 40t'C'_s or frorn about. 150 11IM2 I ~'s at: 4t`3" C
to ,al;aou t ?50 ttlr-ii'is at 40' C, aaid is liydropbc}bic in nat-tire. C?i7e acceptable grease lubricant is a synthetic 1ivc1rocarbon mater-Ãal thickened with silica available, for exaniple, from IN'y~.~
I..ubricants. 1.tiL., of Fairhaven, MA, uxider the Irade narrte "Nye 1`,rYOCEI;:..l.A?~, 670õ Also, oÃlter 1ubricant mat:etials, suc}t as coÃxtmercially avai1a1}le ;yreases, can be eziiploved as desired. Alternatively, the Itibr-ic;aDt c;aD be elittliDated.

Witl7 refCrc;D~:.e to FIG. 4, asscriibly of the sUr~(-YiCal CUttyr~~,~
inst.ruttIc;EIt m0 toward the distal et1d 42 of the oriter trifae 2~2 c~ii l?e descri'bed in oreater tlet:-ai l.'I'lie surggicail crittitlg instru.rnc;nt '20 iw assembled by ~~axially disposing the bf.ariiig sleevf. 24 in the outer it-be :ltanien 50. For exanip:le, the 1~e-aringsleeve 24 is optionally press fit or defines an interference fit wit:lt the outer tul~e 22. The bearÃÃtt; sleeve 24 is secured in the outer tube lumen 50 a.t the first secF.r-~~ent 6Ã,1 best shown in F1G'. 2) such that the l~e-aring sleeve 24 and Ãlze, outer ttibe 22 are su.bsÃant-ially rotationally fix ed relative to oize anotlier.
'~5 Adciitiona11.y, the bc;ian'tig slecvc '?4 can be ~,'ntirely received in the ltaniÃ~i-i 50. For exasiiple, the bearin{,~ sleeve 24 can have sul~st~.x~tiall~~ the same len-th ~.s the tÃrst se{,~zlie~~t 60 of the lumen 50 such tliat wbcn tlic la~,~arilig slcc;v~,~ ?4 is inserted into the oLiter tLibc; lumen 50, the distal termizius 66 ofthe bearing sleeve 24 and the distal ez~~ 42 of the oLÃter tLÃbe 22 are substantially coternlilioÃts. FurÃ:her, s~~ic e,niboc1inicilts inclLacie th e inner passage 68 arici the >0 ;;ecc~iicl segr-iie;nt 62 oi't17e lun7en 50 c.lefiiaiii7g substantially the s~iiie diameter, swcl7 that tbe;re is a substantially continuous effective inner diameter ~=i=cxm the inner passage 68 of the liearin,4~ sl~:~:.~.~~:~'?4 to the lumen 50 of the outer iut~~:. 22 at tl~~.
s~:~c:c~ticl :~~:gr~~.~;i~.t. 6~'(~~f the lttÃrÃerÃ '5t}. Alter ÃiaÃ:ively, a steppedrccliarÃ-iet:e.r trarrsiÃiorr, for exa:rÃ-iple, is also contemplated (see, e,g., wtirgical ctÃttirig instrument 120 crf_I-0ICs. 5).

Witll refcrertce to FIG. 1, tl.Ãe irtÃier wire assernblv 26 is gerterally disposed within the lcÃrr:Ãert 50 (FlG 2) c?i'the c?Liter ÃLibrk 2~'. As farrkvic?Lisly desrr.ribed, a lubricant (riot ~ slt~Avn), stÃch as a ;yrease lubricant, can optionally be disposed along at least a portioÃt or an errÃirety: oi'the irlterface'bet:weerr the irrrÃer w ire asseÃirbly 26 aÃid the i.Ã-i.Ã-re.r surface522 (1<lG
2) of the outer Ãut~e'22, as Nvell as between the iriÃerf'ace between Ãlre, bearing sleeve 24 and the irrr7er` x.6reas;;ernblv 26. Witlr configurations in wIiiclr the outer`
tube 22 includes or forms at least one curved seorÃteÃtt 54, upozi placement ait'the inner wire assembly 16 within th~.~ outer tube 22, the iriÃ-ier wire assemfÃ1y26 assL7mes a shape of tlic or7ter tr7bc `'22, and thus, tlie curved sqgment 54. With this art mirid, the outer tLÃbe 22iinÃter wire asse-rnbly 2t"~ can.
asstarnc; a variety o:f'longit:tÃe$iira:l s}iafaes including crrro or.morc;
curved segments (:fbr.
example, at the curved sc;gtnerÃt 54),ar7t1. or7e or more strtaiglit segments.

Witl7 reference to FIG. 4, at least a fror'tyc3ri of't17e distal sec;ti r7 72 of tlre irrtle;r wir--11 assembly 26 is optiolially disposed in the inner piassage 68 of the beariÃig slc;evÃ~ 24 and extends distally lroztr the (iuter trÃbe 22 arrd the bear-irig sleeve ?4. The distal sec:tiorr 72 of the ir-mer wire assembly 26 c.-arÃ be maintained by the bearirÃg sleeve "=f such tl-rat: tl-re distal section 72 t't.he irirÃer vare assembly m6 does not c rriac;t the irirÃer surface 52 cA the outer tLrbe2'? upon rotation of the irÃner.vire asseÃirbly 26 and,'r:rr while t(-re irrrler wire assemb1y "t>
is stafionatZr. ThrÃs, tlte betiÃ-Ãrig sle.c,vc; 24 sf.rN~f.s to maintain the distal sec.tioÃi. 72 oI'iÃ1r'le.r wire aswrnb:fv 26 such that arr y contact (irrcidrvzit:al or intentional) is at the .irrterkacrv between the bearing sleeve "24 and the distal sectioz~ ~ -1, ratlÃer than contact between the outer tube 2-22 arrd the distal section 711.

irl some embodirÃients, the distal secÃicarÃ ;`2 of the .irirrez wire assembly -ti is supported by tfre bearing sleeve 24 in a sÃ:rbstarltially linear configuration that is free of overt bends or e.LÃr-vc;s. As allÃ.aci~,'ci toabovc;, the distal section 72 of th~,~
inner wire assombly 1.6 is optionally substantially thicker in diameter t}taat the intermediate section 74; such that the clistal soc.tiolr 72 is nr.ore structurally rigid than the intermediate sec:tiorr. 74, fflid thÃ.as rÃ-Ãor~,~
suited to rukaÃiorr wiktrirr a substantially lirtear, or straigtlt, portiorl of the oiater t:iabe -2.

-Ericreasirig the diatneÃ:er of the distal sect.iori 72 c:rt-. the iririer wire asserr-ibly 26 -andror t-se crfÃhe;bearing sleeve 24 sÃ;rvÃ;w several purpcrs-Ã;s. For example, ir-ict'easiiig a thickness of the d:rstal section 72 can increase rigid`Ãty of the assembly proximate the cuttin+.õ tip 28.
Thrrs, the .~sselnbly ir-icltÃdr~s greater resistanc~.~ to bending forces encountered at the cr,ittsng tip 28 during, a cuÃÃirlg operatic}ri as desired. Also, adding rigidity is ofterr particularly advantageous as CL1ttlri:; tr~,l size. 1riGr'e-`ct5e-s (e.=;-., cÃ.ittlri=;-}3lÃ1`S of greater tllail about 2 mm, cutting burs fr-~~iir about 3 mrri to about. 4 rurn, or cutting btars at le;ast about 4 r7irr-1). With increased mass and/or size, inertial forces are potentially incr(msc;c1 at the cutting tip 28, resulting ial a potential for greater vibration or other trndcsirafrle transverse movcnient at th~.~
ctittin4,) tip 28. SLÃeh undesirable movement often :results, an more difficult cutting operatiorr s iricre ase tf :faiigtring of the iritrer wire asser~trbly 26-, increased debris, iricrea;;ed ter-npeza:tr.rres. or otlier factors reducing cutting operaÃ:i(ari efficacy in genera1. Furt.lrez, where th~,~ selected cutting tip 28 hias an increased size, cbatÃer loads on the cutting tip 228 will also increase, whicla M turn increases the bending stress aiid inalaacÃ loads ori the distal section 72 of``the inner wire assernbly 26. The increased diameter of flae distal secta~~
72, in accordance with some embodiments, reduces t:lrestress to more acceptable levels.
According to the examples of'rrrr(lc.sirable c.fÃc.cts describedatrove, vibr-atyc3rt or niovenier-rÃ nial;:es it more difficult to acr::uraÃei~~ c,ut along a desired cr~tt:ir~g l~at(-r without unwanted deviations. Additionally, vibrai7oiis arid increaseci bending du.c to transverse movement fi-om inertial efTects; :rrrclrldirig increases irt both periodicity and degree of berrd, restrlÃ in ater component tatigue, Undesirable Ãxiovement at the cuttang tip 28 a1~~
potentially increases debris g,er-rrvratiorl., for example, irrer~eased tzaiisverse movrv.rnent at the ctrttirrg tip 228 trarisl-aÃes into irrereased tra:rrsverse m ~.~verirerrt of the irrner wire a.ssenil.~ly 26 w7thirr tke outer` tube 22, t}rer-eby irrcreasir7g contact aardior- contact fc3rc;e;;be;i-we;ear the irirrer 2 5 -%.N~are assembly 26 and tlie iÃizier sr.rrtarr?=e 57 2 ot'the outer ttibe 22 and/or tlie iÃizier sr.rrtarr?=e of tlic b~.~ariaig s1ec;v~.~ ?4. Furthermore, such vibration ar-icl added contact can also rr~stilt in an undesirable :Ãr7cr~as-e in te:Ãnperature due to frictional effects.

With tt~e above in mind, the bearfn4,) sleeve 24 is adapted to reduce urldesirable vibratiorial mo'vemelrt at the tip 28, for exan1ple by serving as a vihraticail4r.1 dampener. In >~ particular, the bearing sleeve 24 is ofrtionr7.lly ic3rrriec1 of a vibratyc3rital such as a relatively softer material than a material of th~,~ dista1 region 46 of tlle oLrter tLrbc;
''~~'. Debris frozn the c>rrier i.rrbe 22 and/or irirrcr` xvireassemb(y 26 arc also rcdrac;ed via rrsc of the laearinL,, sleeve '~`~. For example, evith cogitigtirations iri avtricll the distal sectioti 72 atid tl~c. outer` tube 22. come iiito contact, the poteniia( for debri's c;oiilprisiiig pjarlYcles of the (jGaler ttibe'?2 and.,'nr distal section 721 of the iÃiner wire a>senibly 26 exists.
However, where tlie bciaring sleovc '24 is used to maintaiai th~,~ distal section 72 of th~,~
inner wire assembly 26, overall debris f=.t=orn the outer tube 22 and/or inner wire assetiibly 26 can be red~icecl, for e~~~n-iple. by foriiiing the bearing sleeve 24 of a relatively soft material in compari son ÃÃ.~ the iriiier lvyre assembly m6, suc;has PEEK mat.e;ria7s, fo.r extar-iiple, 4ticb relativel;r, sof`t.e;r, or more forglving, materials can be tÃsed to redLice abrasion and/c`xr ln~~act forces froni trirasversÃ' movemÃ?i-it iit the distal section 72 of t-he inner assembly 26.

1t? In ~om~.~ embodiments, dcsigai teEitures of the surgic;szl cutting iaistrLiniÃ~i-it 20; sLacih as material selection ant1 the resultant journal bearing, al1ow f(ar limited exposure ol'tlie inner wire a;;seri-ihly '^26 clistAil t}ic di:tal c;nef. 42 of't:he (auter tube 22, represeaitecl at B in fTIG. 4.
For e:sample;, tlle exposed leaigtli B of the iriner wire a;;semb1y 26 is i7ot greater tliaai about 0.1 inch (about ?.54 nirri); ias another ~,~xianip1e, the exposed lciigt1l B
is not greater tliali abotiÃ 0.05 ixieli (about l. 3 mmf, it beinw understood that otlier dim xisiczr~s are conteznplated.

With reference to 1<IG. L upon assemblv, the proNimal section 70 of the irmer wire assembly 26 is generally eiisposed iD the proxiti7al regioi7 44 of the c}tit.e;r t.tibe 22, and extends from the distal end 42 tfiereof. 'I'l~~ outer tube luzrlen,50 WIG ?)at the proNima;l region 44 is, in on~. f.isibodiisic;iit, substantially (1Ãlear such that the proximal section 70 of the i.nne.r wire asseaxibl_y 26 is sripported in a liÃietir configura:tiÃ7n sUbstantÃally.f:ree {if'bezids or curves. As alluded to abc?ve; the proximal section 70 of the inner wire assembly 26 can be substantially thicker in diameter than t(ie intermediate sectioti 74.
sLicfi that the pro-ximal section 70 is more sÃruct.ura.lly ris;icl. than the. intermediate section 74, atZd thLÃs more sLÃited '~5 to rotation withiii a stabstantially linc;ar, or straight, porti~~i-i of the outer ttibe 21 A. mor~,~
str~icÃLirally ri{~id design aÃ the l~rE~xia~al section 70 is a~l~~at~ta~;eÃ~~.~s Ã~~ znaÃa~ respects. For '.xamp1E,'., tl"#e pt'C3ZImal section 7~.~ is can be rli{lre res14tc'1t7t t4i tC?rslt7ti., flexing, or bending when a rotational force is being i:Ãnparted on the iJii7er wire assembl'y'.16 via the inotor (r<ot In ttirri, at least a pcai-tiot). of the intermediate section 74 of the il~~ier wire assembly 26 caii be disposed in the iiiteriiieeiitatc; regiori 48 o.{`the outer- tube ''~~', For extaTtiple, w-liere l~
the curved se(nMegrt 54 of the outer tulae~22~ is located at the irrtertr-iediate regiori 48; the intermediate section 74 crfÃhe inner wire assenitrl~~ 26 ex-terids through the e:Garv eci s~,~girierit 54 (or segments) and aIso takes on acuro ed slrape, in parÃÃoular, the iritermeciiaÃe section 74 is adapted to be rotated in th~,~ or,itcr tr,ibÃ, 22 wliil~,~ maintaining the c;r.art.~~,'cl shape. As previously desci-ibecl, the interrYÃediaÃe sect:ic}ri 74 has a strbstant:ially smaller diailreter than ttic proximal sectiorz 72 strctr that the intermediate sectiorz 74 defin~s a str1.~statiÃially greater (li~iire(ric; clearance lvitlr the outer` tube 22 t.l~aD a e1.iametric clearance bettivee;rr the Otrter ttr~~C
221 and the proximal sce.tioai 72. As a result, the potential for binding or unwanted intÃ?rtÃ?rencc bÃ?twrÃ?err. the inner -,\.~ire assembly intermediate section 74 and the outer tr,ab~.~
intermediate aegior7 48, due to their aespective curved s17apes, for example, is :reduced.
Adtiitiomally, where provided, t:lr.c sniallc;r= cliarneter of'the itrterr~trediate;- tic;ctii.~i-i 74 car~i help to :iric,r~ease flexibility of the int:errnediate secti(arr 74, thereby also reducing the potential for binding or other unwanted inter=tercnc~,~ between ttic outer ttibc; 22) fflid the inner wire Ãr.ssertibly 26.

The orat:er trabe22 is a7sserrtbled to the hc>usin4.~ 32 ~z~ ii.lr the intermediate re<.~iczr~ 48 and the disÃa1 regÃc?n 46 emendÃrrg distal the housing 32. As previously described, the housing 32 cari be insert ari lded over the otater itabe 22, x.Ot.li the iarrrer wire asserr-ibly, 26 tf~~ii being placed within the luzrlerl 50. 1,11 some embodiments, the c}ptiorlal shoulder 56 of the iiiteÃ-i1-iediaie region 48 provides astopsurt~tcÃ; for posilionin~. <~
against the housing 32 if ~..
desired.

Witli reference WItIG. 5, irr scrrrr.e errr:bodirrrerrts CIre coupling cfir.icl: ')t} is sec,rir~ed to the proximal section 70 of the inner wire assembly 26 bv resÃstaÃtce weldizi;y. lzi particular, a first electrode:1?~ ~iid a secorld electrode are captionally tised to weld the irrrrer w ire asserirbly 26 Ã~.~ the coupling chtacl; 30 witlr a portion of ttic proxinZal secÃioir 70 prQtrLÃding '~5 from. or also, stabstantially cotcr-minous withK the promnral clicl 80 of the eoupling cbu.ck. 30.
`I'lre weld joint is created by applying voltaoe to the electrode E3. A
relativelv large elc;c:tricat cLir-rcnt passes from ttic first electrode EE, through the coupling clitick 30 and the proximal section 70 of the inrrer wire assembly?C>. and to the second electrode E. 'l'he ctir'rent heats tlle coupling chuck 30/inner o.vi.re assembly 26 to the pcaÃrr:t -v\here; the m.atc;.ri:al >0 be;iwc:ear the cle;ctroeies Ej aard E2 ;;ofteris9 trpc3ri coolir7g aritl hardening, a welded joir7t is formed. HowevE;t'. other n1'.tl7odS of connecting the wire assembly 26 to the coupling C:l'#L1C;k >0. suct.1 as via crimping, arealso contemplated.

'i'he. manner ofasserr-ibly usitÃg resistance welclinois aelva:rrfageous ir-Ã
ixlarly respects.
For example, ÃÃsitig ur-iÃrilai.ng in the iabsenue ofrewistwic;~,~ weldiÃig, tl~c. proximal section 70 of tltc inner t~>ire assembly 2)6 ~.~efÃtes, o1apos'trrg tlats (frot >}rot~>n) that are aligned to crinipiaig points of the coupling c1iLick 30 prior to c..ri.mpffl.g.
FÃ.Ãrther, the second passage 90 is ulosed. or is otherwise a<.lalind lro1e." A user performi.Ãxg; the czin-ÃpirÃw,~~rtype assembly ensxrrcs that the proximal section 70 is fiÃ11y inserted irZto the second passage 90, crrsÃÃr'~s that the irirrer x.6re flats are aligned, or- properly itic.lexed, to the c.rirtipiiig points, then stakes, or scoÃÃrc;s, the coupling chuck 30 fflid the irÃnc;r c~~irc assembly 26 in that positioÃl, aÃrd tÃ(timatelv uses a cnmping ttaol or mac(rinc to crimp th~.~ cottpling, cihÃ.acik 30 to the ii7nÃ?r wife assembly 26. From tltis, it should be understood that more potential tiar user-induced ii-ie;fie~:aeÃ~icioti e:sist. 1i-i particatilar=, ;;uc1i nietliociolcr~;y, irrc~.luciitÃgaligtrrr:Ãent steps, can be 1iiglily user dependent.

C,lar the other br7.nc1, with resistance welding, the proximal section 70 of the ir7arer wir`c assembly 26 is iaserted iÃ-ito th~,~ secolicl passiagc 90 of the coupling chuck 30 aÃ-icl extends proximally frczm the coÃÃplarrg c(iÃ.zc:l;. 30. IÃr tlus mzr.xr.Ãrer., the user per#c~rrrlrntf assembly is able to better ensure Ãlrat the prcrxintal sectioÃt 70 has beezt properly iÃaserted irtto the coupling chuck 30. Furtlrer, resist.aD~:.e x.velcling.{orms a swl;astarrtitallt si:r' arger- connection bet.:veerÃ the in.Ã-Ãe.Ã= wire assembly 26 and the corÃplirÃg chuck 30. In paÃ-tic,rÃlar, an actua1 weld of rriateÃ'i,al is formed, rather than gonerati oÃi of a mechanical i ÃÃ
terf ereÃice, or c.ri mp.
However, eÃ-Ãrrip#ng; resistance welding, or other rztetlrocls of connecting the iirÃteÃ- wire assembly 16 to the c,oup1iÃtt; cltuck 30 are all -,v~itltÃÃt the seai1ie of the present iÃtveÃrtioD.
With reference to FIG. 4, the cutting tip 18 is attached to the distal sectiozt 71crf the irÃrler wire assemb1v 26. '1`he cr:rttirrc, tip -8 caÃi be secLÃred to t(-Ãe distal sec;t:ioÃi 72 via a.
variety of means, iricltÃdirrg braziri4.?, laser welding, adhesives, threads or screw means, and 2~5 othc;r means for c:onrÃc;c:tiiig or fasteÃ-iiiig, iÃ-icltÃdiiig those already clesc:ribed above, AlterÃtatavely, Ãlre c,uttiztg tip?8 can be substantially continuously formed wit:lt the distal s~,'c:tioÃr "?'? (see, e.g., surgical ctÃttiÃ-ig instrÃ,Ãnr.ent 1220 of FIG.
6).

Returning to FIG. 1, clr7ring Ã.asc, a mcÃtcxr (not shown) is coiiÃiectecl to tlic hor7siaig 32, witlÃ the drive atlechaÃlisri-Ã (rtoÃ sltowri) cottrlecÃed to the cotaplirig chÃ~~~ 30. 1'he Ãlrotor is then operated to rotate t1le coupling chu.ck 3 )0 qr.lid thtÃs the isrne;r wire assembly 26. Rotatit}ri of the iarrrer wire asserribly 26 relative to the outer ttÃbe ?'' caar c;reate 'a rc3taiiri~ jotÃrn~al bearing betaveen the iririer wire assembly 26 and the inner srir-tace S" (FEG
2) of the outer ttibe 22, alor-ig at least a laor-iiciri of a length of the otder lt-be 22.
For exaniple, a jour2ia1 liearin+.õ can be forrtiect laetweeri the pr-oxÃrtial section 70 of the inner wire assembly 1-6 and th~,~ pro\ima1 regiori. 44 of the orrter trrbc; 22), Additionally, ajou.rnal t~earingis optionally 5 (,eneratetl betweeri t(-re inner wire asse.rnl?lN, 26 and the l~e-arirlg sleeve 24, If desired, a jor.rrnal bearing can also be torrrzed bctvvcen t.lic irztcrrneciiat.c sect.iori 7=1 of the inrzer wire assembly 26 aDd the orrter trrbe~'2.

Wliere; provided, the lrabI-icrlrlt., t:or examplea grease lul;ar-icar-it-, can ~,~enerr7.te a hydrodynamic jair.rrnal iiearizi~? andior combÃÃtataon rotating arirl hyrlr~~dynarni~ joÃrmal 10 bearing betw'eI7 the inner wire assembly 26 e23-1Lt the lnnet'surfÃ1GG 52) of the outer tube 22 upon rotation of the inne:r wire assembly 26. The lubricant also opt-ional:lv forms a trN=cfrottynarnic ~otrrna1 bearingAirrci/or combination rotatii-ic-, and hydrotlyrrar-aie:: jot.rrnal bearitig between the iiirier wire tlssr;mtalNY ~~ aDd the bear-irig sleeve m4 t~por7 rotation of the inner wire assembly 26. R:c;g .~rclless, so2iie configurations include the surgical cu.ttir-2g 15 inst.rrameni. 20 being cliaraLterired by the absence o.[`a bzrll b&3r-irig assembly beiiveerr t(ic outer ttrbe 22 and the inner wire assembly 26.

'I'he surgical cut:ting instrument '(# of tl-re preserit invenÃican is capable c}I'ma.iritai2-ri.rx(f its ;;t.i-tic;tra.ral integrit.yat highly elevated r-ovational speeds. For exarrtple, the st$Ergical cutting irrstrurrlerrt -0 is operated at rotational speeds in eNcess of 50,00U W'N4, such as about.
20 80,000 RPM, as desireci l;'u.rtlic;r-K c;mbodimf.nIs where the inner wire assembly 1-6 is fomleci ot'M'" toÃ7l gtee:l., Clre inner surface 52 Ã7i'ttie outer tube 22 is highly polished, tizid a g;rease lul}ricant is disposed betwven the inner -,v~ire asseml}ly'226 azid the inner surface 52 rif the outer tube 22, h-ave beeri surprisingly found to provide mariv advantages.
:E{car eaar~ipl:e, such corltigtÃ.rati~.~~~~ allow the outer tul.~~ ~2,/inrler wire assembly 26 t~.~
include the curved 2~ segment 54 extending through a raciius of curvature such that the proximal r~,~gi.on 44 and the distal regdon 46 exteÃtd at aai azi;yrrlar offset A of al}out 15", for example, although other climclisior-2 are contemplated.

Thus, the r=csr.iltant surgical cutting instrument 20 t~acilitate bigh-speed sur~gica1 ctitÃirig procedures witli riiiriirYlal interference to t:l-re surgeon's visibility via the si-riall outer diameter and/or c:.trrve;d riatu.r~: of'the outer trrbe; 22/Ãnner wire asserlihly "6. The minirrIal be;,at ge;nerabon rerider-s the surgical cutting instrument. ~~'C3 hig,14 safe for virtually ~71l surgical applicatioÃis, as does the ixrini~~ial exposed IetÃgÃ:lÃ B of the igiÃier wire asserÃ-ifaly 26.
FtÃrtht;r, tl.Ã~,~ outeÃ fube 22, is highly, stiff: greatl.y, prom.ot.ing l.ÃiaÃlcilitig aiid tÃwe citÃriÃÃg a surgical larocedLire. `I'he above-described pert(yrfÃiarÃee attr'tliut:es are optionally ftÃrt.lÃer improvc;c1 c\.-ith a harcleÃ-iecl material coatilig (c;,g., diamond-like coating) oli th~,~ inner wiÃ-~,~
assemlaiv 2Y. While each oi'the above-described features material select:iolis, processiiis;-, and lubricant selection) have a syner~?istic etfict in producing a viable, high speeei, low profile, ct.ÃrN~ed wqgical cutting instrument, irariatyc3tis oÃ7 c3Tie or r7iore of these features can be employed fflid remain within the sc.op~.~ of ttÃ~,~ present invention.

For example, aai alternative suaoical cutting instrument 1.20in accordance with principles of th~.~ preseÃ-it invention is ciescribecl wi.th. rc;fereÃ-ice to FIG 6. 1Ã1. general tenris, tlie surgical cuttiÃ7g inst-rumetlt 120 includes features and operates according to principles subs-t~sitiAilly similar to those described iii association the stirgical cutting ii-istrutyieÃ~it 20 (Fl:G. 1.). With this in ariitid, the ;;t.ÃrVc;a1 ctÃttitig in;;trt.ÃrÃ-ient 120 includes a wpport ttibe 1.22, a beas-ing sleea e 124, aÃi. i:nner wire assembly 126, a. cuttlng tip 128, a.
coÃ,ipliiig e.huck 1 3 M a hczÃ.Ãsatig 1 3~~'. :Ãndar~ ev.Ãpo.Ã-:Ãtyvecoolin<.~ sleeve 134. sÃÃr~ic~~l Luiiyn.gr instrument 20z the ÃÃÃneÃr wire assentb1y 1.'?t"~ is coaxially disposed within a lumen 'l 50 (F1G, 7} formed by the oÃÃter tÃÃbe '122, x.0th the otater tube 1.22 iticlÃÃclingal leas't one curc~ed seg.Ãnent 154.

'1'he outer tube 17" detiÃ-Ães a.proNimc-i1 eÃ-Ãtl 140, a distal eiic1 14,22 (F:1G 7), a prc}xirÃiaI
region 144 term1Ãlatiiig at the proximal csid 1.40 arici a cil:tal regloÃl 146 terminating at lhe distal end 142. I'1Ãe OÃ.it:er tLtbe 122 also includes an intermediate .re6o:Ã7 148 exteÃ7di:Ã7~
betwven the paoximal and distal regions 144, 146. The outer tube 12.2 delines one or Ãxlore, iritler rli-arÃieteÃ~s with the- lurÃien. 150 e.Ntendinot:rotii the proximal etirl 1.40 to the tlisui1 eÃld 142 of tlze, oLÃ:ter tLÃbe, 122, 't'he outer tube 1 2'caAi det:ÃÃi~ a curved pro:f-ile (e.g., the crtÃ~~ed segÃ~aieAiÃ. 154) at or along the intermediate regioÃ-i 148. With a. curved or bent profile, the distal regioii 146 is angularly offset from the proximal reoion 144. As descril~edin association with the surgical cutting instrument 20, the oÃ,iter tÃ,ibÃ~ 221 is optionally constructed to tacllitate foÃ-i~iatiol~ of a ro~tating:IourrÃal 1_aearir~~,~ li.e., firictiÃ.~nal sliding journal bearing) relative to the irrrÃer 'w ir~
asseÃnb1y 126 in conjunction with a ctÃrved c;onwtru.cti.on. Alternatively, the otÃter ttÃbe; 122 carÃ be stÃ-ai gl7 t.

With reference to FIG. 7, the outer tube 1222 cletir~es, in some en-ibc~din-ients, tfrree ir-itier dsaÃneÃ~,~rS at the ltrmeri 150.. For example, the ltrmeri 150 inclt-cies a first segment 1.60 at a first diarrteter, a serr.ozt~.~ segmertt. 16'? at a seeorid diaÃiteter, and a tliircl segntent. 163 a.t a third cliani~,~ter. Th~,~ first segment l6t.~ origiiiates at the distal end 142 fflid extends proximally t.h.Ã=c~up,Fr the tfi;ta;l rep.ion 146. I'be secorrcl se4~,'nient 16? extends prox-imally from the fi rst segm ent. 160 ÃÃ.~dN--ard the i iiÃer'rnediate. regior1 148. -I'hc t.li ird segm ent 1 6;' ) pr'oxirritally fr' rri the second segr7ierit. 1.62 tlirc?ugli the ir7terttic;d.iate region 148 aDd the prozimat regioii -1,44 to th~,~ proximal encl. 140 (FiG 5).

'1"he first segpeÃat 160, including the t=arst diameter, can be adapted to receive at least a portioai of the bearing sleeve 1224. For example, th~.~ first segment l6t.~
is optionally sizecl and shaped, or ot17envis~ adapted, to receive tlie l_iearin4y Sl~eve 124 in a press tit. The secoricf ~i-icf third segtiier~its 162, 1.63 are sized and shaped, or otherwise adapted, to receive a portion of the inner wire assembly 126. 134 w-ay of'r'eferenc;c;, in on en 0r1-lit17iting c;nibodsnicr-it, the first ~egmrent '1 60 has a diameter of alaotÃt 0.060 inch 0.5' mm}. lt stiotilcl be understood that a rir.rrtiber of (iElier dimetis:ions 4~re~rter or l.esse.r-;~ are also c~c~titet~rl~l~rtet~..
The bean'rig sleeve 124 i ssubstantially sariii(ar to the bearitig sleeve?4 {1-^f~:.~. 2) previously d~scribecl. -I'tle bearing sleeve 1 "=f defines a. prc}xinial ter=r-rurius 164 and a distal teriiiir7trs 166 lviÃh tati inner passage 168 extending from the proximal terr-ninus 164 to the distal tertri.irius 166. Gerleralk,, Ã:he'1~eaz:irig sleeve 1 ~4 defines a bearing sLrrkace alor-rO the inner passage 168. AdditioÃlally, thc;bearing sleeve 1.24 is adapted to be ir~ser`fed i.nto Ãhe OLit:rvr tLibe lrrrrrerr 150 a:t Ãlre distal end 142 o.f'tfre outer tube 12".
For e-\aynple, the bearing s1~~ve, 1N is optionally adapted to be press fÃt, or otherwise define an interference fit, witliirl the outer tr:rbe1tt.rnen 150 at the distal errcl 142 of the outer ttibe 12~2.

With reference to F:IG 6, the ir-mer wire assembly 126 det:rries a proNitrial sect:iori 170, a distal sectior-r 1.72> ar-rd an ir-rterrtlediaÃ:e sectaori 174, tli e inÃ:ern-aediate secti orl 174 between the proximal sce.tioli 170 and the distal sootior-i 172. As ciescribecf above with reference to the sLrrlgical cuttÃrtginstrument 20 (FiG. 2), theintermediate sectiozt 174 can be more flexible tliari at least one of the proxin-ra1 sce.tion1.70 iancf the distal scctior-i 172. For example, theinÃ~ern-aediate section 174 optiortally rle:f-ir~~s a subsi.ankially ;;n-aaller diarYteter than, and/or is formed of a material(s) different trorli, one or bcath. of t1le proximal wectit}ri 170 aiid the distal secÃ:i(arr 172 in order to provide relatively rr-i(are flexibility to the int.r;r-mediatr,~ section 174.

Witll refcr-ertce to FIG. 7, the ctiÃlYr-ig tip 128 is substantially similar to t(~c cuttsrig 1iP
28 (F1G. 1) pre4-,iously described, aÃ-ad irrclr.rdes a ccrttirr{,~ bur 176 aÃ-ict an atta:chrzteztÃ end 178.
~ In soÃxte embodiments: the dÃstat section 1721 of the iztÃaer wire assembly 126 is connected to the at:tac:1-rmerrÃ: end 178 bv irrtec,.rally f:rrmin(f the distal sectic}ri 171 of the ir-mer wire -issemblv 126 arrd the oxrtÃirrg tip 128 as sh~.~dN--rr. For exanZple, t.lre irZrier wire assembly 12.6 aiid the ctaÃtirig tip 128 c;aD be nrac}rinedfrr.}rn a single fricce r.}f stock mtaterial.
other Ãxtethods of connection are also contemplated. For er;a.rnple, the cuttirtg tip 1218 can be separately formed aiid sr.ibseÃlu.ciitly attached to ac\.-ire otlicr-wise defining a r~.~niaiiider of the inner wire assembly 126.

With refererlce to FIGS. 6 and 7, ttie coupling c17ttc1';=. -1:30. the housir7g -I321 al7d the evaporative cooling sleeve 134 are substantially similar to the coupling chuck 3 )t?, the }r trsitig 32, and the evaporative cooling sleeve 34 (FIG. 2), respectivelv.
In gerieral terms, assembly of t1ic su.rgical crrttirig dci ic:el.2t7 includes disposing the bciari:ng sleevc 124 i11 the orater trabe l.urrtert 150. l11 turn, the i.rr.tIc;.r- Wrr-~. asserribly 126 is coaxially disposed in the otiter ttilae 122 and tl-re bearing sleeve 124 (as secured in the or.it:er ttilae 122). A portion of the proximal section 170 of the irrrrer wire asserr-ibly 126 pr-~~ects pro:sirtial1y from t17e proximal erld 140 r:rf. the r:rtrte.r= ttrbe 122 -and a portion of the distal section 1. 72 proj~ects distal.llr from the dssÃ:rl. rv;nd 142 ofthc; outer iGrbr;. 122 X-V-it.h l}te cutting iip 128 secured thereto. `I'17e evaporative cÃ7crlirrg gleeve 134 is opticrwxlly provided aiid is secLrrecl or formed about the outer tube 1,221. 'I'he housing 132 receives arrd maintains the proximal region 144 of t(-re outer tube 172 and the coupling chLrcl;: 130, w:ittl the coupling cliuc,k U )U cor-mected to the proximal sect-ion 170 of the inrZer wir'e. assembly 126.

't'he assembly of the surgical euttirrLF irtsÃ:r urtierlt 120 toward the distalrewFiorY 14[.~ of th~,~ or,iter tr,ibe l'2 is ciescribecl in niore detail with r=ef;r-~,'nc;e to FIG. 7. As prc;vioLrsly described, Ãlte bearin{~ sleeve 1.24 is disposed in the first se~ment 160 of the oLÃter tLÃbe lumen 150. For example. the 1=Seariiig slc;eve 124 is optionally substantially the sar-nc; length as t(-re Ci rst s~~,~rr-aerit 160 of t:be Iumerr 150 sric:(-r that w:(-rert the faearirro , s1eeve 124 i;; irrserÃe~i into the outer tr.ahe ltrrnc;.n 150, the bc;anng sleeve '124 and the distal erid 14" of the outer ttrbe 1''~~' are substantially coterminous. ln ttrr-rr, at least a por-tiorr of the distal section 172 of the inner wire asserxlbly 126 is disposed in the innerpassage 168 of t.lie 1~earirig sleeve 124 ttr-id exterrcis ciistally froiil the outer tube 1221 wid the bearirrg sleeve 124. The dsstal sectioÃt 17" of tltc iÃiner t~>ire assertrbly 1~?6 can be maintained by the beaz-in{,~
sleeve 1.24 sric,lt that th~,~ dista1 sectsorl 172 of the ifl~~-ier wire assembly 1'26 does not contact tlic ii-iner surface 15 2 of the otitez ttifae 122 upon rotation of the irlrrerwire asseiirbly 1226 aricfr'or wlrile the inner asseml.~lNi 1216 is staÃioi~arv.

For exainple, although the distal section 1722 of tlie iriner Nvire assembly 126 projects proximally L'r ari the bearing sleeve 124 ir7to the second segr7ierit. 162 1'thc; (auter tube Iu.n7er7 150, the bearing s(eeve 1.24 serves to maintain the distal secticyzr 1722 of inner wire assembly 11.6 suc.li that any cc~i-itact (incidental or irltentiolial) is at the interface between the lseszriiig sleeve 124 aÃrd the distal section 17?, rather tl7ar7 contact between outer tube l22 and the (1istal soctii.~i-i 172. l:ir par-tictr1ar, the iarrrez passage 168 of the bearing sleeve 1`24 clefiries a smaller tlir7.iireter than the second diameter of the ltir7ieii seconcl s~gmeart 162. In this manner, the c;ffc;c:tivc ifl~~-ier diameter Mcluflc;s a stop fl-orii the ii-iner passage 168 to tlic sec.t~iid segment 462 ot'tlre, outer tube lrrmerr 1SO. A stepwise or other ty-pe of iricrea:se iri relative size c?1`the second diameter relative to the diameter of'the iztÃaer passa;ye 168 lrelps erisra.re that the distal section 172 is rriairrtainec.l by the bearirig sleeve 124 rather t1i~ii laeirig supported c1:irect1N, by the oriter tube 122. For ex.aiirple: the third diairreter ol'the third segment 16") of the outcr lt.-tre ltirrrerr 150 is sto~pecl down in size.
relative to the second segrztertt 1621. 'l.,his f-w(ps errsrire that the distal seet'lorr 172 of the Ãrtzter- wire assefrilaly 126 does not bizrd or otherwise uztdesiriilily interfere with the outer tube 122.

'I'lre dÃstat section 1721 of the iztÃaer wire assembly 126 Ãs stippc?atecl by the bearing sleeve 12N in a strbstanÃiallv lane<~~~ confio,uration, or :is otherwise free of overt bends or ctirves. As alltided to above, the distal section 172 of t.lle irrner- wire assembly 126 can be 2~5 substantially thic:l:er in diarneter than the int:c;rrr~ediat~,~ section 174, sLich tlriaf tll~,~ distal section 172 aztd the proximal section 174 are zncyre rigid tltaÃt the intermediate section 174, alicl thtÃs provide greater structural stTcrlgth alicl are more su.itecl to rotation within a.
substantially linea:r, or straight, portion of the outer ta.llie 122. As p,-evioL,sly described, the intermediate socticail 174 cctri be substantially thinner, aric1 there;foro able to flex more easily.
>0 As strclr, the intermediate ~ectior7 174 adapted to extend il7rotrgli one or r-irore cur`ved s~,>grliÃ'i-its of th~,' outer tube 12?, stÃch as t1i c curved segm cIit 154, and adapted to be rotated ttierc:ixr without rar~~uefai74.~L~ir~~; cir resista~r~.~:~ to r~~~E~.Ã:ic>xr.

Ari(atfier srirRical cuÃÃirm) irrstrrimerit. 72(} in accordance with pririciples t(le preserit invention is desc.r-ibed with refierence to F1G 8. The uutlYr-iinwt.t'u.ment 2?0 is similar to previous embodiments arid iÃ-icludes ari or.itet-tr.ilie 222, an iime:r wÃr`e assembly 1-1-6, a cutting tip 228, a cor7pling chuck 230, and a liotising 232. Oflicc again, the inner wire 5 assembly ?26 is coaxially disposed w.ittriri a Iuriierr 250 formed by the oritez trifae -222 tllat oÃlZeizvise optionally iricltrdes a curved segmeiiÃ ~54. Further, an intermediate tul.~~ 2l"2=f is disposecl be;i-we;er7 the (auter trrbe '?m'' and the iainer wire assen-ib}4 226 along the cure,,et}
segmcnt '254-'1"lae outer tube 2222 optÃoria(ly assurxies any of tlie forms previously described Nvith 10 respect to the cutting lnstrrrm~.~nts 220, '120 (FlG& '1, 5), as can the cotip1iiig cihr.ac:k-?it.~ fflid tlie htarÃsiz~~~ 232. "I'}ie .iruier wire ass-embly 22t"~ includes a first or proximal secta(aJi 270 atid a see::oiiel or ii-it;eriiieciiate section 274. Tlie first section 270 is optionally a rigid shaft or wire to w}iich the t:.oupllr7g c;litic;k 2310 is secured or integrally f raried.
The second section 274 c;xter-ic}s distally ffroiii the first section '270 and in sorlic erlibodinicr-its, is a sprilig wire akin to 15 the irine.r wire assemblies 26, 426 lzreviorasly rl.esc~ribed. That is to say, the secc>rid sectiorl 274 assume any ol'tiie forms previously described witii respect to the irlrier -,v~ire assemb1Ães 26, 126. The tirst antf second sections 270,274 can be separately fi.}rrtieti ari(i fastened together laserwe}tl, s:iriterir-r ;, arid others), or integrally iormecl from a s:irigle piece of stock. material. Regardless, in some cisibodiisicsiÃw, the second soc.tit3ii 274 defines a 20 diameter less fl-ian that of fl-ie first section 270, bavin{,~ an axial length substantially corximerlstrrate -,v~ith aai arc length of the curved segment 254 of the crrÃter trÃbe 222.

'I'lie cutting tip 228 can iziclude a cutting bur 276 and a sha4't 278. The sha4't 278 extends distally from the ctrÃtinobrir276 aricl is aÃ-tacl~ed to the s~corid sectic}ri 274 of the inrler wire asseml.~1y12,26. NIso, the shaft 278 can 1}e fornzed as part o1'the irlrl er dN.-ire '~5 assembly 226. for example ias a dista} section of the inner wire assembly 226, with the cutting btrr 276 subsequently attached thereto. For example, tlie shal:t "78 is optionally of an icl~,'ntical coiistrr,ictsorl as the first section 270 . 1~=veti.
fi7rtllc;r th~,~ crrttiaig tip 228 fflid the inner wire ascen7b.1v ?M can be izite4~ra11v fc~r:Ã~~ed. 1~e4~~rdless. the second secta(yJi 274 is formed to have a diameter less than that of the shaft 278.

The clianict:e;r of the sec:t}rici section 274 c.at). be smaller than that of the first section 270,and t.heshafÃ 278,,as the secotic.} sectyc3ri 274 does tic}t r7eed to srrppc3ri the beaidiaig }(.)tad inrlucedbythecuttingfar:rr ?76, '1'his coristrrictiori has tl~~ poterrtia.l for aJloe:Vir1g arecltreed ratlitis seecirici section 274 at tl~c. c.t-rv~,'ci segÃl-ier-it. 2.54 (tilon~
o~-lli~.l~ tl~r,~ sf~~.c~}r~tl section 274 resides upon final assertibly) and serves to reduce the friction load/heat in the curved segment 254 .
~ The interziiediate tube 224, also described as a bearizi;y sleeve 224, is provided beÃweeri the sec,orirl sectiori 2~74 -and tl-re outer tube 222 to support the secorrcl sectic}ri 274 upon rotation of t.lie inrier wire assembly 22.6. The iriÃer'rnediate Ãrrl.~e 222=1 carz be fornied of a I'''IT 11 mtaterial: tal;;o, other flexible t-trbirig r-iiateTials cari be empIo;re;d. 'I'he interniediate ttrbe 224 can be substantially intlexÃb(e atid resistant to beridrzig. 'l-,he interÃaiedÃate ttrbe 224 acts, with som~.~ configurations in acc.or-flanc.e wit1i princ:iplcs of the present invention; to n7odÃfy the effective inner diameter of the outer ttralae 222, such ttlat ttie effective irir7er (liaiaieter o.#'tfie otiter ttibe 222 is stepped dowti M the secc~sitl section _174.

L)trring r.rse;, the sÃrrgic:al cutting Ãn.str.rnient 220 operates in a rliariner highly similar to previous erribod.irricrits, ln particular, a motor (iic3t. slic3wn) rotates the inner wire assembly 226 relative to tlic oLrter tube `22 sLrch that a rotating journal bc;ering is createfl beiween,aÃ lcast a portion tyfthe iriner wizc, assembly 226 anrl arr inncr surface 252 ot'the otiter tulae-722. A cF.rease (ar other lubricant is optionally disposed bet-ween poÃ-Ã:ioris of the iririer wire assembly m26 ~iicl the outer tt.rbe 222, t:or example alor7g the i~ar-st section 270 arrclr'or the shaft 272 of the c.uttir-rt~ tip 228 sLrch that at high rotational speeds. a.
hydrociynar.riic bearing is established along tl-ie.. outer` tube 222, Sir.riilar t.oprevious erxibod.irxierrts. Clieri, the surgical cuftirig i.rrsArr.rnie.rrt 220is, adapted to provide a rro:miri{rl rotational speed of 80,0[30 l~.f'M with a low protile, curved outer tr.rl~~ 21-127 assembly.

Another surgical er.rÃting iÃistrrrniezit 3220 in accordance with priziciples of the preserit invention is shown in FlG'S. 9A. atid 913, `I' -re surgical c,utti.rxg instrument 320 incorporates sealir-r~.~ features whacfr can be irlcarporated into otre or rnore of the surgical cutting instru.mcnts ci~,~scribeci above to mininiizc; tlow ofmaterial. into or out of the oLrter tube and/or act as a bearin;J.õ surface. For example, FIG. 9r1. is a side., cross-sectional vi~-%v of tlie surgical cutting instrument 31.0 akin to embodiments described in iassociation with the surgical cutting insÃrui-rients 20, 120, 2220. '1:'fre siar~,~ical cuttirig instriarnent 320 includes arl tip . , , 3~? outer tube ' ~2~?. a sealing t~ also described as a hc;arrr`r.~ sleeve _324, an tnner ~.a~tre;.
assembly 326, a cutting tip 328, a coupling chuck>-"W, atid a br.}tisirig 331 The sealing i~ip ;; r ~'~

324 is attached to, atid extends distally from, a distal region 346 oftl~e otifer ttibe 322, and provides a bearin~.is~,~ali~~~; surface that more ~:1~}sel~r :~pproxis~l:~l~~s asi outer t~i:~Ãli~~ter ~~fÃl~t;
inner tvire assembly 326 of the sun~;Ãeal cuttin{,~ instrunient 320, tl-iris lÃ.mitinpossible izital~e and/or release of material from/to tlic su.rgicat sit:c;-~ Tlae sea.lizt;y t:ip 32~Ã can be forÃxied of a ceramic or poly zner material, fcYr example sappliire, and exhibits enhanced hardness aiicl surface finish as c(atiiparetl to t(-~e oriter tube 32.1 Thus, the sealing tip 3'?=l has elevated wear characteristics, itzcreasiii.; a life of a bearitig foriiied bet~~~~~ii ttic ;;ea:ling, tip 324 aiid the in.ner wire a;;searibly 3 )26. Further, cera.mic Ãnaterials can be ziiore readily ntaztufactLÃred to exacting tolerance requirements as coniparecl to steel (as is otherwise optionally tisecl fcxr the outer ttibe 322) s~ich. that an inner lumen or iiuier passage 368 of the sealizi(y tip 324 has a diameter less than a diameter of the lumen 350 ot:'t:he otiter tube 322, restalt:ii~ig in a rc;dticecl diametrical c~.learane~:e relative to t}ie iritier lvire aswn7bly :326 Tliis redtaced clearance, in turn, .further prevetits r'liaterial frrorn c;nteriflig an&or ezitsnR tlic oL7ter tL7tzc 3 )22. For example, th~,~
ltÃm~,'n 368 of th~,~ sealing tip :+24 u3ri be rnanufac:Ãu.red to provide a diarrtet.r:ical clearance relative to ttte ar~~ielr- X.Yire assembly 326 in Ãlte range tif from abotit 0.005 ntm to al}out 0.01 mÃn, altlaorigli other dimensions are als accelytable, The sealing tip '124 cari be assembled totlre otiter'tube:>?2 ina irariety ot .{ashions, For e.:~ampIe, the outer tube 322 c-an forrii an internal aperture or counter-bore :3 )60 at a distal ei.id 342 thercof; having a diasileter adapted to t-eceive ari outer diameter of lhe sealing tip 324 via a close slip fit, or ti press fit. W:itFi this confi g, rira tiÃ7n, aÃi adhesive or.retaMM":
coixil~~'itirad (ztot shown) optaonal ly secures the sealing tip 324 to the outer tube 3,221.
Regardless, in c}iie eint?odi.~~~ent, the sealiii4.~: tip 3 )24 ancl,r .Ã= the outer tube 32- are c(arrffi,)t~~~ed to provide a longitudinal interf~ce. l~~igt.li of at least. 1. 5x a dÃ~ineter of the seaiiizg tip 324 to '~5 miai~-itain sf7tÃarc;n~,~ss and striaightness. Bc;c;aLis~,~ the s~,~aling tip 324 is longitudinally straigbt, an overall leÃt(;tli is optionally relatively sltort wIteÃi employed with a curved configuzation ofthc outer ttala~,~ 322), To provide a sufficient bearing surface, the sc;aliiig tip 324 bas a length in the range of from about 8 mm toabotat 14 mm although other dimen'siot~s are c~ntem.plated. Finally, the sealing tip 324 has ail outer ciiarncter coniniclisurate with, >0 optionally less than, that. I't.he outer ttibe 3''~~?, ,and can fortn a distal taper 363. For ~~~~t-npl~,~, the swaling tip 3~4 can taper froi~i about 1.. 5 mm tc) iat~out 2 .5 nini in outer cliameter, althou4~1~ ~~tlier dir~~~.xi~;icir~s ~.rc also acceptable.

f_:r7rbodirr-ients of surgical cuttirrg itrstrLirr-rerrts of the presetit invention provides a marked i.rr1prcrv~.'Ãl-lent over previous desi"gnls. By eliiillÃlatiiig a ~~eeci fcrr a ball bearing assembly in eorrjunctiort with desired Ãitateria.l selections artd laroces>ing teclrfr'tclues, the outer sr7pport tÃibe can 1iavr~ an outer cli~t-neter significantly less than other available surgical instruments aJorlg witfr optimally located arrrl sized curved sectic~ii(s), wlrile providing requisite stitfness. Further, material selection and, where desired, lubricant, allows for lÃ.~iig-teriir lri~,~lr-sl~eed rotation ( ar the order (.Yf 80,000 RPM) witlr rti itiirtral irrstr-u.n7er7t wear and bcat build-up. 1~iiia11y, embodiments of'the sr.irgica1 ctÃttii-ig instRrmeiit oft1lc pre-s~.'nt invention require a miniana1 aittnrber= ofc:tanrponents, thiis reducing costs aaicl assÃ?mb1v #ianc.

1 t? L?~ic to the high speeds of operation, c;r.art.-~.~cl, low profile fcatr.ires, c;rr-iboflsments of tlie surgical cutting instrumertt of the present invention can be used in adN~iÃle variety of surgical applications. C~i-ie;- field of possible alsplicatii.~i-is isr.cludes trair:iercru: rrou:ro-ot;ology frrocetltires, such as c c}r1ea.r irtiplaart, vestikrular tie;r-ve; section, facial arerve decompression, c;nflolympbatic hydrops, and removal of tumors of th~,~ car including acor,istic n~,~r.ar~~la surgery (e.g., rriirlrllc and laczsterior- fiossa a7lalaroac.bes), clrainage c>1'pet.rczus apex c_y si.s, alr.d zirastoÃdect~-)mies, to name but a few. lrr addiÃÃc?n, the sur{P
ical cutting instrument of the frreseart irrvr;rrtior7 CaD be trsedÃi.}r a variety of otlrer bodily procetfu.res, strclr as those relating of l~~:rrie spurs c}ri tlr.e z~ertel~rae. removal of artf~r~itic.. l~~:rtre spurs to s~iiLi> >trr~;e.Ã ~: removal throughout the body, spirra1 disc surgery, ksi~;~;. sGarg~;.r~~, liip :~rr~~~~tZr, ~~rflir~lae~li~. su.r~~~ical.
proeedLiresz and otlter-s, In rtrore, 9eÃ-aeral terrtrs, t(tc sur`.õica.l cutxizt`õ instrument ~.a:zr be employed to remove, re-sect, ctiÃ, or debulk any bodily material (e.g., tassue, bone, eÃc.).

Embodiments of the ItÃg1t speed sur;yirr=a.l cuttizt y izrsÃrtiu~r~rrt of the present inventioÃa can be emplovecl in. the debulkirrc, arld,"Vr resecting of borie. E{car~
~xartrple, etirbodiiirerrÃ:s includÃrzg a larger cutting tip (c.s;., lraving a diameter of greater than abotrt. 2 ririn, from '~5 abotÃt 3 mm to about 4 mn-r, or about 3 n-rni or greater) can be employed to pcif%xrm the debulking operation. It slrould also be understood that embodiments including suclr larger cutting cffli also be eniploved to perforni a resecting operation or a portion tlrercof.
C'onve:rselv, e:ÃtrbodÃ:ÃtreJrts including a cuttin4y, tip having a diameter of abotat '2 mn7 or lecs cari b~: employed to perfcrrni the resecting operatson, or e;~~~en tlre, debr,fl kÃrrg operatiori or a >~ portion tliereofas elesireel, During elekrulkitig, anc1:'or rese;dirr.g, tlle stargic"al cuffing iaistrGar~~~~i-it 20, 120, 220, 3?0 is deployed atrd operated (c,g.; at speeds of at least 50,000 R1?Tir1-, inc1udiriL, speeds of alaorit 80,0(30 RPM) to resectldelaulk Ã:he'borle through tlle facial Tf'ct',ws.

Embt2d1meÃl(s of the surgical cl.](t12ig instrument of the pt'cse1-it 1i1vf'.IIt1C)17. with tl~c.
curv-ect confÃwuratiori optiort;dly protect the facial nerve as the outez-ttibe extends irrtt-) the ~ facial recess, tlatrs minimizizl;y exposure of the facial rrene to the rotatirig inner wire that might ot(-re"v ise unexpectedly coriÃact the facial neÃ~~~ and,1'(ar cause ttlermc-i1 damawwe, FLÃ.rtlier, the eLÃ.r=ved, riiiriimal outer diameter features of the surgical eLÃ:ttirlg irlstrtrriierit of the pr'eserit invc;nti:or7 affords tliestlr~,~eon vastly improved visibility o.fi the surgical site as corlipared to conventional cutting devices.

Although speciffic embodiments lia.ve been illustrated and described herein, it will be apprcciat~,'cl by those of or-dinian, ski1.1 in the art that a variety- of alterrlate and/or cf7rÃivalent implementations may be sulist:itÃ,rted for the specific em~odiments shoNk=n and described -vvithout departing from the scope oftl2e prc~selit invention. This applicatÃolils iiltend.ecl to cover ariy adaptations or variations I'the spe;cit.ic en-ibc3tfinic;nts discussed liereiri.
Therefore, it is intended that tliis invention be limited only by tlic c;1ain-Is ar-Icl the equivalents .
tlier-eof

Claims

1. A surgical cutting instrument for use with a motor having a drive mechanism, the instrument comprising:
an outer tube defining a proximal end, a distal end, a proximal region extending to the proximal end, a distal region extending to the distal end, and a lumen extending from the proximal end to the distal end;
a bearing sleeve, being substantially tubular in shape and defining a proximal terminus, a distal terminus, and an inner passage extending from the proximal terminus to the distal terminus, at least a portion of the bearing sleeve secured within the lumen of the outer tube;
an inner wire assembly defining a proximal section and a distal section, the inner wire assembly extending through the lumen of the outer tube and through the inner passage of the bearing sleeve;
a cutting tip connected to the distal section of the inner wire assembly;
a coupling chuck adapted for connection to a drive mechanism of a motor, the coupling chuck being connected to the proximal section of the inner wire assembly; and a housing maintaining the proximal region of the outer tube and the coupling chuck, the housing being adapted for connection to a motor.

2. The instrument of claim 1, wherein the bearing sleeve has an inner bearing surface bounding the inner passage, the instrument further comprising:
a grease lubricant disposed between the inner wire assembly and the inner bearing surface of the bearing sleeve.

3. The instrument of claim 1, wherein the bearing sleeve has an inner bearing surface bounding the inner passage of the bearing sleeve, and further wherein the instrument is configured such that upon final assembly and rotation of the inner wire assembly, a rotating journal bearing is established between the outer surface of the inner wire assembly and the inner bearing surface.

4. The instrument of claim 1, wherein a diameter of the inner passage of the bearing sleeve is less than an inner diameter of at least a portion of the lumen at the distal region of the outer tube.

5. The instrument of claim 1, wherein a diameter of the inner passage of the bearing sleeve is substantially the same as an inner diameter of at least a portion of the lumen at the distal region of the outer tube.

6. The instrument of claim 1, wherein the cutting tip is a bur defining an outer dimension of not less than about 3 mm.

7. The instrument of claim 1, wherein the lumen of the outer tube extends along a first segment at a first diameter and a second segment at a second diameter, the second segment being formed proximal the first segment, and further wherein the first diameter is greater than the second diameter.

8. The instrument of claim 7, wherein the bearing sleeve is received entirely within the first segment of the lumen.

9. The instrument of claim 1, wherein the lumen of the outer tube includes a first segment having a first diameter, a second segment having a second diameter, the second segment being defined proximal the first segment, and a third segment having a third diameter, the third segment defined proximal the second segment, and further wherein the first diameter is greater than the second diameter, and the second diameter is greater than the third diameter.

10. The instrument of claim 1, wherein the inner wire assembly further defines an intermediate section between the proximal and distal sections that otherwise each define an outer diameter that is greater than an outer diameter of the intermediate section, and further wherein at least a portion of the distal section is disposed within the inner passage of the bearing sleeve.

11. The instrument of claim 1, wherein the distal terminus of the bearing sleeve is substantially coterminous with the distal end of the outer tube.

12. The instrument of claim 1, wherein the distal region of the outer tube extends at an angular offset relative to the proximal region of the outer tube.

13. The instrument of claim 1, wherein the bearing sleeve is formed of a non-metallic material.

14. The instrument of claim 1, wherein the bearing sleeve includes a plurality of exteriorly projecting ribs.

15. The instrument of claim 1, wherein the bearing sleeve is non-rotatably mounted to the outer tube.

16. The instrument of claim 1, wherein the bearing sleeve has a length in the range of 0.27 -- 0.65 inch.

17. The instrument of claim 1, further comprising a cooling sleeve disposed on an exterior of the outer tube.

18. A method of performing a surgical drilling procedure on bodily material at a target site of a patient, the method comprising:

providing a surgical cutting instrument including an outer tube, a bearing sleeve disposed in the outer tube, an inner wire assembly, and a cutting tip, the inner wire assembly being co-axially disposed within the outer tube and bearing sleeve and the cutting tip being connected to the inner wire assembly and positioned distal a distal end of the outer tube;
exposing the bodily material at the target site;
deploying the cutting tip against the bodily material, and rotating the inner wire assembly within the outer tube and the bearing sleeve such that a distal section of the inner wire assembly is maintained by the bearing sleeve and a proximal section of the inner wire assembly is maintained by the outer tube to initiate a cutting interface between the cutting tip and the bodily material in contact therewith.

19. The method of claim 18, wherein the inner wire assembly is rotated at a speed of at least about 50,000 RPM.

20. The method of claim 18, wherein the cutting tip includes a bur having an outer dimension of at least about 3 mm.

21. The method of claim 18, further comprising:
establishing a rotating journal bearing between at least one of the inner wire essembly and the outer tube, and the inner wire assembly and the bearing sleeve upon rotating the inner wire assembly relative to the outer tube and the bearing sleeve.

22. The method of claim 18, wherein the outer tube defines a curved segment

23. The method of claim 18, wherein the method is performed as part of an acoustic neuroma surgery.