US2638092A - Intramedullary nail inserter - Google Patents

Description

May 12, 1953 J. F. DORR 2,638,092 INTRAMEDULLARY NAIL INSERTER Filed Sept. 15, 1950 5 Sheets-Sheet 1 INVENTOlZ James F. Dorr HIS ATTORNEY a w 5 w m a m0 0 a m M m 2 8 V5 ..m5 1% N e w J. F. DORR INTRAMEDULLARY NAIL INSERTER May 12, 1953 Filed Sept 15. 1950 Patented May 12, 1953 STATES oemica INTRAMEDULLARY NAIL INSERFI'EB; James; FLcDm-r, Sam Jose, Galiil,zassignoriofiones third tmWilIiamrSeward andmnewthird to Martini.l-Payme,-.-bothi at San Jose; Calii:

Application September 15, 1950;SerialNo.1843987 Claimsn (CLYIZBfi-SU- 1 Thisfi nvention rel'atesto 'a tool' for'use'inr'orthd pedicasurgery and more particularly-' to improve merits-in anintrz'nnedullary nail inserter and? ex:- tratctori I i In the art ofhbdne surgery it 'has becomethe practiceto usea fracture fixation'mean in the I marrowpassage'ofth bone-structure: a For purposes of thdpresent disclosure a nail which is diamond shaped in cross. section is shown: This form=*of-"nail;when driven'directl-y into the" marrow -pagssa-geof the bone;- *hasproven most satisfaetoryinpreventing turning of the nail within thamarrew passages of" these fragments? Such diamond? shaped'nails are A preferablyzprovided witneyes adjaeenttheir ends to facilitate withdrawal of the nail by meansofa hdok'connected to theeye in either'endof'tlr'enailif Qther" forms 5 ofrpins" may he provided Wlth'fa threaded" B fort'conneetion-toa'a tool havingra threadedsocket. Orieobj'ectr'of the toolbf'the presentfinvention istdfacilitate a positive" inserting" or extracting forceiaxiallyofthpinor nail clespit'ewariations i'm offset-"'01" angular disposition ofthe 'pin: relative to the" outer extremities of "the limb or" member embodying thebroken bone:

Another obj'ect'is to" provide arr intramedulla'ry nail insertei and extractoi' wlrich wiil fabi'litate axial movement of "such na-il without-twisting or tuming the-sames Another obj ec't -is- =to provide an intra-medullary nail. inserten' and "extractor which will -minimize flesh' lacera-ti'ons-and bone chipping; cracking or splitting-during inserting an extracting ofsu'ch nails These and other obj'etts 'and advantages" of'th'e resent invention will 'becom'e apparent from "a readirigmf the followingdescription-in'tl'ielight of the drawings in which:

Fig; "1 is a perspective viewoftlrenail inserting to'ci "ofthe present'invention.

Ffxz isa perspective view of a nail extracting hdo'k 'ad'aiited'for use the tool of Fig; *1.

Fig. 3 is a sideiview the tooiotFigrl 1 with thenail extracting hook-ofFi'g: 2 associatedthiexe with.*

V Fig. t is a sideiview of the'toolofi-Eiatrr, xpan tially broken away and with a partrthereot ad;- justed-into extended offset position.

Fig. 5 is a side =view of a simplifiedform ofithe tool shown in Fig; 1.

Fig; 6 is a sectional: view of-an anvil head em:- ployed with the simplified "form shown in Jiigfifi.

Fig; '7' is a front viewof a; human l imblillustxafiiingthe tool of-Fig'i- 3 in use entraetinig' animtram-ednllarypin or nail Fig; 8 is a sidev-iew of a human I'imb' illustrating'the tool of Fig. 3 usewforextractingiam intramedullary: nail:

Figs is a perspective View illustrative ef the tool shown in Fig.4 in use it whil'e insertin'gl a nail into a lower femur and knee jgoint of-the human leg.

The tool-of the presentinventioneomprises a main shank M having both its ends" 1 I and! threaded. The base end I l is threadedly secured toan ofistbar Bee-as to form an L. 'Thxflpposite end of the barl3 has a threaded bore H adaptedtoreceive a drivingtip t5 l)- or-an extracting hook Hi (Fig. 2) astheease-min, be, Both the hook l6 and thetitrl 5 are providedwith a knurled look nut 1 I i for fixedly securing either of themtothe bar- It to prevent thirremoval therefrom during use of the tools" The opposite threaded end I 2 oftheshanbhas a knurled lock nut 18 thereon by which an anvil head 19 (Figs. 5 and 6) is secured to the shank after being threaded'onto theend i2. Tfihek 'nut I8 is also useful inlocking an offset-anvil armzfl fFi'gsxl, 3 and 40 the threaded end l2'of the-shank IBso as to maintain the arm 20 at" a fixedradial position relative to theshank H!- and relative to the radial-disposition of the bar H thereon.

Anelongated head 22" having a threaded connectingend 23- is secured ma threaded soelret fl in the arm 28 in parallel relation tothe shank i0 butoffst therefromi This elongated-head 22 has a knurled outer-surface'for providing a nonslip' gripping surface for the surgeonshand and is also providedwith an anvil head 25at itsfree end.

The driving tip 15" is provided-With a concave end M for properly seating the-tip -|5-" upon-the end of the nail N to be driven. Howevergthis end 26' may well bethreaded; if desiredyfor db rectconnection. to the threaded end of a nail if such a threaded end-beprovided thereonw Since the diamond shapedna-il N is preferred; no twisting or turning of such nail N should occur. In other words, if the nail N were turned, a reaming effect would take place within the marrow passage of the bone and the bone fragment to be joined might become loose from the nail which might possibly cause disalignment of the bone fragments. Therefore the importance of rendering the inserting or extracting tool mobile relative to the nail without twisting and turning the nail is apparent.

The tool of the present invention is calculated to insert or extract the nail N without unduly twisting or turning the nail relative to the bone structure in which it is or has been embedded.

Referring now to Figs. '7 through 9 it will be seen that once the point of entry of the nail is determined, a wound is opened up in the flesh of well be at any intermediate location, as best illustrated in Fig. 9. When it is considered that a patient being treated is seldom conscious during the pin inserting or extracting procedure it will be appreciated that the limb under repair is relaxed. In other words, the flesh on the limb will be limp and often distorted due to the weight of the patient and dependent upon the position in which the patient is lying. Furthermore, the distance from the axis of the broken bone to the outer surface of the limb will vary in different patients. Consequently, it will not always be possible to swing a mallet adjacent the limb to drive the pin or nail into the marrow cavity of the bone. Therefore, in order to prevent undue tearing of the flesh around the wound, it becomes necessary to attain a greater range of freedom for swinging the pin driving mallet M in forcing the nail N into the severed bone.

At the outset, the mallet M may strike the bar I3 directly behind the driving tip I5 as seen in Fig. '7. However, as the bar I3 passes into the open wound it becomes difiicult to strike the bar I3 with the mallet. From this and in Fig. '7 it will be seen that the anvil head I9 is more accessible and can be struck with sufiicient force to drive the nail N further into place.

Since the anvil head I9 is secured to the end of the shank I and the latter is offset relative to the axis of the driving tip I and nail N, it will be seen that the mallet can be swung with greater ease than would be possible closer to the flesh. Moreover, since the driving force of the mallet is transmitted substantially axially of the driving tip I5, even though the anvil head I9 be replaced by the anvil arm 28, greater ease in swinging the mallet can be attained by striking the arm 20 further out than the axis of the shank Ill (see Fig. 9). The tool can be steadied by gripping the knurled surface of the elongated head 22 and the anvil head 25 of the latter can be struck with the mallet with equal effect to drive the nail N home.

It should here be noted that the arm 20, as well as the bar I 3, is free to swing radially relative to .despite the position of the patients limb and body.

After the pin is sufficiently embedded Within the bone to join the severed parts thereof the .wound is bandaged and the patient allowed to move about without the need of a cast or outside splint. Due to the fact that the nail N is firmly embedded within the core of the bone and was not twisted or turned while being inserted, by means of the present tool, the severed parts of the bone will be secured in alignment irrespective of movement of the limb. Thus the patient may be up and about in a short time and'may even put his weight on the limb embodying the bone under repair without fear of misaligning the knitting bone structure.

After a reasonable time for knitting of the fractured bone structure the nail N is preferably drawn out of the marrow passage. Thus the point of entrance wound is again opened up so as to expose the eye in the end of the nail N. The tool, then assembled with the extracting hook I6, as seen in Fig. 3, is employed. Here again the mobility or adjustability of the tool relative to the axis of the nail N is important. Thus it will be noted that the laterally extending tip of the hook It can be set at. various radial positions relative to the axial connection of the shank of the hook I6 on the bar I3. This is accomplished by setting the hook at the desired angle and then locking its threaded shank against the bar I3 with the knurled lock nut IT. The radial or angular disposition of the anvil arm 26 relative to the shank I0 is likewise adjustable by first set ting the arm 29 in the position desired and then looking it in place with the lock nut I8 upon the shank In. a

Once the tool has been arranged with the tip of the hook and the bar I3 and arm 20 in a desired position, the tip of the hook I5 isinserted into the exposed eye of the nail N (see Fig. 8). The underside of the anvil arm 20 is then struck with the mallet M to unseat the nail N relative to the marrow tissues within the bone. Once the nail N is loosened from the marrow tissue the tool may be struck by the mallet either upon anvil arm 29 or the bar I3 in a direction to extract the nail from the bone.

Should it become difficult to swing the mallet due to an improper angular disposition of either arm 28 or bar I3 relative to the patients body, the tool can be readjusted in a facile manner by loosening the lock nuts I! and I8 to permit the arm and bar to be turned relative to the shank It and hook I6, respectively.

During extraction of the nail N as Well as during insertion thereof it is irrportant that the nail N be not turned or twisted. In this manner the marrow tissues of the bone will not become unduly disturbed; but more especially, cracking, splitting or chipping of the bone is. avoided.

From the foregoing it will be apparent that the tool of the present invention aids in quickly and successfully inserting and extracting an intramedullary nail into and from a bone to minimize the possibility of misalignment of the severed sections thereof. Further, the present tool assures against any undue twisting or turning of the nail during either inserting or extracting optration to minimize disturbance of the. marrow tissue. In either extracting or inserting operation of an intramedullary nail with the present tool, a wide range of mobility of striking surface is afforded thus assuring against unnecessary laceration at the entrance wound or accidental cracking, splitting or chipping of the bone under repair.

While I have-described my intramedullary nail inserter and extractor in specific detail it will be apparent that it may be modified, varied or 'alteredin many respects without departing from the invention thereof. I therefore desire to avail myself of all modifications, variations and alterations as fairly come within' the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. A tool for moving an intramedullary nail axially within a bone by hammer blows comprising a shank, an offset bar extending perpendicularly from one end of said shank, and having fiat hammer impact receiving surfaces on both sides thereof in directions lengthwise of the shank, a nail engaging element secured to the free end of said bar to extend parallel to said shank; an anvil arm secured to the free end of said shank for extension radially therefrom and having hammer impact receiving surfaces on both sides thereof in directions lengthwise of the shank, and locking means mounted to lock said offset bar and said anvil arm in various positions of rotative adjustment relative to said shank and to each other for providing striking surfaces on said offset bar and said anvil arm free and clear of the flesh surrounding a bone in which said intramedullary nail is being moved axially.

2. An arrangement according to claim 1 wherein a striker handle is mounted to extend from the free end of the anvil arm parallel to the shank.

3. A tool for moving an intramedullary nail axially within a bone by hammer blows, comprising a shank, an offset hammer impact receiving bar secured to extend laterally from one end of said shank, a nail engaging element secured to said bar in laterally offset relation from, and parallel to said shank, an anvil arm mounted to extend laterally from the opposite end of said shank from said impact receiving bar and rotatively adjustable about the axis of said shank relative to said impact receiving bar, said anvil arm having a hammer impact receiving surface thereon at right angles to the shank axis, and locking means mounted to lock said anvil arm and said impact receiving bar in selected, relative, angularly adjusted position.

4. A tool for moving an intramedullary nail axially within a bone by hammer blows comprising a shank, an offset hammer impact receiving bar secured to extend laterally from one end of said shank, a nail engaging member secured to r said bar in laterally oifset relation from, and parallel to said shank, an anvil arm mounted to extend laterally from the opposite end of said shank from said impact receiving bar and having a hammer impact receiving surface thereon at right "r in) angles to the shank axis, said anvil arm and said impact receiving bar being relatively angularly adjustable about the shank axis, an elongated head with a striking face at its free end extending from said anvil arm in offset relation and parallel to said shank, and extending in a direc-- tion opposite to the direction in which said shank extends from said anvil arm, said handle having a hammer impact receiving surface on the free end thereof, and locking means mounted to lock said anvil arm and said impact receiving bar in variable angularly adjusted positions about said shank axis. 5

5. A tool for moving an intramedullary nail axially within a bone by hammer blows comprising a shank, a hammer impact receiving bar extending perpendicularly from one end of said shank, nail engaging means secured to said bar in laterally offset relation from, and parallel to said shank, said nail engaging means extending in a direction opposite to the shank from said bar, locking means mounted to lock said bar in various rotatively adjusted positions relative to said nail engaging means, an anvil arm secured to the opposite end of said shank for radial extension therefrom, an elongated head having a striking face thereon extending from the free end of said anvil arm parallel to said shank, said elongated head extending in a direction opposite to the shank from said anvil arm, and locking means mounted to lock said anvil arm in various rotatively adjusted positions relative to said shank and to said bar for providing a striking surface on said tool free and clear of the flesh adjacent a bone within which said intramedullary nail is to be moved axially.

JAMES F. DORR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,235,419 Callahan Mar. 18, 1941 2,528,941 Bassett et a1. Nov. 7, 1950 FOREIGN PATENTS Number Country Date 118,595 Sweden Apr. 15, 1947 OTHER REFERENCES The Journal of Bone and Joint Surgery for January 1944, page 55.

The Journal of Bone and Joint Surgery for July 1949, advertising page 4.

Zentralblatt fiir Chirurgie for 1943, page 1659.

(Copies of these publications in Fig. 55.)

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