Augmented external fixation of unstable distal radius fractures :

Transcription

1 Rankin et al. The Journal HAND. Parkinson RW, Hodgkinson JP, Hargadon EJ. Symptom.. atic non-union of the carpal scaphoid: Matti-Russe bone: grafting versus Herbert screw fixation. Injury 989;0:6-6.. Parren SM, Huggler A, Russenberger M, et al. The reaction of cortical bone to compression. Acta Orthop Scand 969;5:9-7.. Milford L. The hand. In: Crenshaw AH, ed. Cambell. operative orthopaedics. 7th ed. St. Louis: CV 987: McLaughlin HL. Fracture of the carpal navicular (scaph-, oid) bone. J Bone Joint Surg 95;6A: Moran R, Curtin J. Scaphoid fractures treated by screw fixation. J HAND SURG 988;B:5-5. Augmented external fixation of unstable distal radius fractures : The technique of "augmentation" of external fixation employs the use of percutaneous Kirschner wires to secure the radial styloid fragment as a lateral buttress, elevate and fix in place the depressed lunate fossa fragment, and, when necessary, add support to the elevated articular surface by means of subarticular bone grafting. A series of 5 cases of comminuted, unstable intraarticular distal radius fractures has been managed using this technique. Detailed evaluation has demonstrated precise articular reconstitution with an overall satisfactory result rate of 9 %. (J HAND SURG 99;6A:00-6.) William H. Seitz, Jr., MD, Avrum I. F roimson, MD, Robert Leb, MD, and Jeffrey D. Shapiro, MD, Cleveland, OMo ExPerience in the management of unstable distal radius fractures using the principle of ligamentotaxis through external fixation has undergone a recent evolutiom a-5 Improved surgical technique and fixation devices have been reflected in improved results with fewer complications.i, 6, 7 However, careful evaluation of radiographic results, even in those patients with acceptable clinical outcomes, has led to the observation that well-reduced fractures have the potential t6 undergo late displacement and/or collapse with loss From the Hand and Upper Extremity Surgery Clinics, Department of Orthopaedic Surgery, The Mt. Sinai Medical Center, Cleveland, Ohio, Received for publication June 9, 990; accepted in revised form Oct. 5, 990. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: William H. Seitz, Jr., MD, Department of Orthopaedic Surgery, The Mt. Sinai Medical Center, One Mt. Sinai Dr., Cleveland, OH 06. //6995 of the initial articular congruity (Fig. ). Recognition of this potential for displacement has led to the evolution of the technique for augmentation of external fixation with percutaneous Kirschner (K-) wire fixation major articular fragments and, when necessary, supportive bone grafting to maintain adequate art-~cular elevation (Fig. ). Materials and methods Data. Fifty-one patients; ~ with an age range from 8 to 98 years (average age, 50 years) have been treated by augmented external fixation and followed-up for! to years after operation (average,.5 years). All patients had sustained unstable intraarticular distal radius fractures consisting of a major radial styloid fragment, lunate fossa fragment, and significant dorsal and/or volar comminution (Fig. ). Nine (6%) of the tients underwent bone grafting (Table I).... ~"~i Surgical technique. All patients had either general" i endotracheal, or axillary block anesthesia. A "limited open surgical approach" was used for insertion of fix- :! i ator pins in the ~adius and proximal aspect of the index 00 THE JOURNAL OF HAND SURGERY

2 Journal 6A, No Augmented external fixation of unstable fractures 0 :V Mosby.at (scaph.:.,gnition olution ixation of the, supalar,~l- om 8 reated for dl paradius ment, nd/~r il paneral, mited ~f fixindex Fig.. Musculotendinous forces acting across the wrist tend ~ ~!~;.~i: ~ to cause the radial styloid fragmento displace laterally and ~:~:i the lunate fossa fragment to depress. and middle metacarpals? This technique employs two -inch incisions, one centered approximately 0 cm to the radial styloid over the radial aspect of the forearm. The interval between the extensor carpi radialis longus and brachioradialis is identified. The radial sensory nerve is identified and carefully retracted these two tendons from under the brach]o{adialis. Direct visualization of the radius allows central insertion of the pins after predrilling. This avoids eccentric drill placement and/or multiple ]~ ig.. After restoration of length and alignment by the external fixator, Kirschner wires have been percutaneously inserted under fluoroscopicontrol to "lock, in" the radial styloid buttress and support the elevated lu~aate fossa fragment. drill passes, which can result in significant weakening of the bone and pin loosening. 7 Distal pin insertion, liikewise, is made under direct vision guided by image intensification, placing the proximal pin through the metaphyseal bases of the index and middle metacarpals and the distal pin through the shaft of the index metacarpal alone. This provides pin purchase in a total of six cortices while avoiding violation of the interosseous compartments. Once pin insertion has been done, the external fixation device itself is applied and then the

3 0 Seitz et al. The Journal of HAND SURGERY Fig.. Patient : Satisfactory result. A, Unstable iintraarticular distal radius fracture in a 60-yearold man. B-C, External fixation has been augmented using radial styloid and subarticular lunate fossa pins with subarticular supportive bone graft. Kirschner wires have secured a concomitant scaphoid fracture. "initial fracture reduction is obtained, again under image intensification control. This initial reduction achieves restoratibn bf overall length and radial tilt. At this point an additional mm of traction is applied through the device, resulting in an increase of mm in the measured joint space of the radioscapholunate articulation compared to the midcarpal articulation. This traction applies tension across the dorsal and palmar radioscapholunate ligaments, keeping them taut during the period of immobilization (allowing rapid return of flexion/extension on removal of the device). With the radial styloid realigned to the shaft, a smooth 0.06 K-wire is inserted percutaneously and obliquely from the tip of the radial styloid across the

4 Vol. 6A, No. 6 November 99 Augmented external fixation of unstable fractures 0 Fig. (Cont d). D-E, Two years after operation the patient has a normal wrist both functionally and radiographically.

5 0 Seitz et al. The Journal HAND SURGERY Fig.. Patient : Poor result. A, An unstable intraarticular distal radius fracture in the left wrist of a -year-old man. B, Augmented extemat fixation has not achieved an anatomic reduction. The radial styloid fragment has not been adequately aligned and the lunate fossa fragment has been over-reduced, creating an incongruous articular surthce and narrowing of the distal radioulnar joint. No bone graft was used despite 7 ram initial shortening. C, One year after operation the patient has a narrow painful joint with degenerative changes at both the radiocarpal and distal radioulnar joint. He has subsequently had a wrist arthrodesis. major fracture site and secured in the ulnar cortex of the shaft. The radial styloid thus secured acts as a buttress. A free 0.06 K-wire is inserted percutaneously under image intensification control dorsally. It is used to elevate the lunate fossa articular fragment so that it is precisely congruent with the remainder of the distal iradial articular surface. With this fragment in the reduced position, a third smooth K-wire is inserted percutaneously under image intensification control transversely from the radial aspect of the styloid fragment directly underneath the subchondral bone of the elevated "die-punch" fragment (Fig. ). Additional subchondral K-wires may be percutaneously added as needed depending on the degree of comminution. Permanent x-ray films are then obtained to evaluate supportive bone stock beneath the elevated fragments. If a significant lucency is encountered (usually seen with initial depression of 5 mm or more), bone grafting is done through a dorsal approach. Final x-ray films are then obtained to ensure congruence of the radiocarpal and distal radioulnar joints) When this is confirmed, a bulky soft compression dressing is applied and immediate postoperative rehabilitation commences. Results All patients were evaluated for active range of mote!on, grip strength, pain, function, and by careful radiographic analysis. A satisfactory result required radiographic restoration of anatomy measured by radial length, tilt, and articular congruity. Additionally needed were range of motion and grip strength within 80~ of normal, freedom from pain, and functional use of the wrist. An unsatisfactory grade resulted from failure to achieve 80% of normalcy in al!. categories. Forty-seven (9%) patients ~had satisfactory results and ~had unacceptable results. One was due to inadequate initial reduction and fixation and subsequent progressive collapse resulting in an incongruous painful wrist joint (Fig. ). One patient had reflex sympathetic dystrophy. Two patients demonstrated diminis.hed grip strength and ulnar-sided wrist pain. Complications were confined to the case of reflex sympathetic dystrophy and articular collapse due to unrecognized inadequate reduction and fixation. Minor complications included five patients with superficial pin tract infection. All patients responded to oral antibiotics without need for pin removal. At the time of device removal, (6%)

6 Vol. 6A, No. 6 November 99 Augmented external fixation of ~nstable fractures 05 0 fixator pins were loose enough to be removed by hand, but in no case did loose pins result in loss of fixation. There were no fractures through the pin sites, no injuries of the radial sensory nerve or tendons of the f,~reann, no cases of intrinsic contracture, and no deep infections. Discussion Successful management of the unstable intraarticular distal radius fracture with external fixation requires precise restoration of joint congruence and skeletal alignment.8.9 This technique has, however, been reported to carry a high complication rate. Evolution of the surgical technique from "pins-in-plaster" and improved ~~xation devices has helped reduce treatment-related ~:omplications. -, 5. The evolving rationale for augmentation of external fixation in the management of unstable distal radius fractures recognizes that during treatment late settling of initially well-reduced fractures can and does occur. This rationale has been supported by cadaver studies in our laboratory whereby "induced" unstable distal radius fractures with major radial styloid and "die-punch" fragments have been artificially created. Despite support of an external fixation device, forces created by muscle- :endon units traversing the wrist tend to cause a lateral/rotational displacement of the radial styloid fragment and impaction of the lunate fossa fragment. Simple addition of K-wires, although only "internal sutures," is adequate to resist these forces. This has been borne out clinically with a high rate of satisfactory results and specifically with an extremely high radiographic rating. Our ability to adequately manage the challenge of the unstable distal radius fracture lies in our ability to restore anatomy while limiting our treatment-related complications. Our past experience has demonstrated that a limited open surgical approach combined with pins of adequate size can avoid bending and breakage and provide appropriate bone purchase; fixation to the radial shaft and six cortices of the index and middle metacarpals allows pronation and supination while helping to minimize the complications related to the pin/bone interface. 7 An external fixation device that allows pin insertion before fracture reduction while providing adequate stability and clear fracture visualization in all planes simplifies the surgical technique and therefore minimizes potential device-related complications. 6 Although a fairly close anatomic restoration can be achieved through closed reduction, maintenance of this reduction can be lost without additional internal sup- Table I. Data on fifty patients treated with augmented external fixation Bone graft Number Age II Sex (Y or N) Weeks in Follow-up fixator Result (YR) 76 M N 5 S M N 5 S 6 M Y 6 S 6 M N 6 S 5 7 F N 6 S 6 8 F N 6 S 7 8 M N 5 S 8 7 F N 5 S 9 5 M Y 7 S 0 6 F N 5 S 7 F N 6 S 60 F N 5 S 5 F N 5 S 66 F N 5 S 5 67 F N 5 S 6 7 F N 6 S 7 F Y 5 S 8 58 F N 5 S 9 80 F Y 5 S 0 M N 5 S M N 6 S M N 6 U 6 F N 6 S F Y 6 S 5 5 F N 6 S 6 M N 6 S 7.9 M N 6 S 8 0 F N 5 S 9 67 F N 5 S 0 ~ 70 F Y 5 S F N 8 U 65 F N 6 S M N 6 S 8 M N 6 S 5 M N 6 S 6 F N 6 S 7 M N 5 S 8 9 M N 5 S 9 7 F N 6.~ S 0 9 M N 6 S 56 F Y 5 U 98 F Y 5 S F N 5 S 5 F N 6 U 5 5 M N 5 S 6 6 M N 5 S 7 7 F N 6 S 8 69 F N 5 S 9 69 F N 5 S 50 5 F N 6 S 5 60 M Y 8 S S, Satisfactory; U, unsatisfactory..

7 06 Seitz et al. The Journal of HAND SURGERY port. Once fixed in place with a K-wire, the major radial styloid fragment acts as a buttress for the lunate fossa fragment and the smaller periarticular fragments of dorsal and/or anterior comminution. Use of a K-wire as a "joystick" to elevate a depressed lunate fossa fragment is effective in restoring a congruent transition from scaphoid fossa to lunate fossa of the distal radial articular surface. Need to elevate the lunate fossa 5 mm or more after radial styloid reduction and fixation has demonstrated a void of metaphyseal bone. This requires a supportive bone graft behind the transverse subarticular Kirschner wire. Addition of this limited internal fixation and bone graft in appropriate cases has not resulted in an increased complication rate, has provided superior overall results, and has demonstrated a maintenance of articular congruity by radiographic assessment. The importance of immediate postoperative hand rehabilitation and patient education in activities of daily living and in pin-site care cannot be overstated. REFERENCES. Kongsholm J, Olerud C. Plaster cast versus external fixation for unstable intraarticular Colles fractures. Clin Orthop 989;:57.. Andrianne Y, Donkerwolcke M, Hinsenkamp M, et al. Hoffman external fixation of fractures of the radius and ulna. A prospective study of 5 patients. Orthopaedics 98;7:85.. Cooney WP. External fixation of distal radius fractures. Clin Orthop 98;80:.- "~. Seitz WH, Flatow EL, Putnam MD, Dick HM. The treatment of unstable distal radius fracture s by a technique of external fixation utilizing a limited open approach. Orthop Trans 986;0: Seitz WH, Putnam MD, Dick MD. The limited open surgical approach for external fixation of unstable distal radius fractures. J HAND S~JRG 990;5A: Seitz WH, Froimson AI. Reduction of treatment-related complications in the external fixation of unstable distal radius fractures. Orthop Trans 989;: Seitz WH, Froimson AI, Brooks DB, et al. Biomechanical analysis of pin placement and pin size for external fixation of distal radius fractures. Clin Orthop 990; 5: Jupiter JB, Knirk JL. Intra-articular fractures of the distal end of the radius in young adults. J Bone Joint Surg 986;68A: Melone CP. Articular fractures of the distal radius. Clin Orthop North Am 98;5:7. 0. Weber SC, Szabo RM. The severely cornminuted distal radius fractures as an unsolved problem: complications associated with external fixation and pins-and-plaster technique. J HAND SURG 986;A:57. I. Green DP. Pins and plaster treatment of comminuted fractures of the distal end of the radius. J Bone Joint Surg 975;57A:0.