SURGICAL TECHNIQUE

Reduction of Fifth Metacarpal Neck Fractures With a Kirschner Wire Xu Zhang, MD, Xiangye Huang, MD, Xinzhong Shao, MD

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are among the most common fractures of the hand.1,2 Patients with fractures angulated more than 45 in whom reduction is not performed have less grip strength and poorer function.3 Closed reduction is commonly performed by the Jahss maneuver.4 Flexion of the metacarpophalangeal (MCP) joint to 90 relaxes the deforming intrinsic muscles and tightens the collateral ligaments. The physician then applies a dorsally directed force on the metacarpal head through the flexed proximal phalanx. However, the Jahss maneuver is not always successful at achieving reduction. Possible reasons include lack of physician experience, impaction of the fracture fragments, and certain oblique fracture patterns that counteract the reduction force. In addition, the maneuver produces compression force on the fracture site, which may shorten the metacarpal. Strauch et al5 demonstrated that every 2 mm of shortening results in 7 of extensor lag of the fifth MCP joint. An alternative reduction technique was reported by King and IFTH METACARPAL NECK FRACTURES

From the Hand Surgery Department, Second Hospital of Qinhuangdao, Changli, Qinhuangdao; and the Hand Surgery Department, Hebei Medical University Third Hospital, Shijiazhuang, Hebei; and the Department of Orthopaedic Surgery, People’s Hospital of Zhangqiu, Zhangqiu, Shangdong, China. Received for publication June 29, 2014; accepted in revised form March 14, 2015. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Xinzhong Shao, MD, Hand Surgery Department, Hebei Medical University Third Hospital, Shijiazhuang, Hebei 050051, China; e-mail: shaoxinzhong@ sina.com. 0363-5023/15/4006-0029$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2015.03.015

Beckenbaugh6 but that method is even more complex. We have employed a percutaneous pin technique to reduce fifth metacarpal neck fractures. The objective of this report is to describe a percutaneous joystick technique for reduction of fifth metacarpal neck fractures, followed by transverse percutaneous pinning. We also provide the results in patients treated with the technique. This reduction technique can also be a backup option when other closed reduction maneuvers have failed.7,8 INDICATIONS AND CONTRAINDICATIONS Indications An indication for our percutaneous joystick reduction technique is a fifth metacarpal neck fracture with apex dorsal angulation over 45 , with or without a rotational deformity (Fig. 1).9 Patients who have failed Jahss or other reduction maneuvers are candidates, as well. The technique can also be used during open reduction, although our report includes only patients treated by percutaneous pin fixation. Contraindications Contraindications are severe comminuted fractures in which no fulcrum point exists for the reduction using a Kirschner wire. Closed reduction of fifth metacarpal neck fractures more than 2 weeks after injury often fails because fracture healing has already begun. Fractures in association with infection, rheumatoid arthritis, or gout may also be contraindicated. A fracture with palmar angulation is rare. A reduction Kirschner wire must then be placed in a reversed maneuver.

Ó 2015 ASSH

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Published by Elsevier, Inc. All rights reserved.

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This article reports on a percutaneous joystick technique for reduction of fifth metacarpal neck fractures. The technique was performed in 76 hands. Reduction was achieved in all cases. The technique is a useful reduction maneuver in the treatment of fifth metacarpal neck fractures. (J Hand Surg Am. 2015;40(6):1225e1230. Copyright Ó 2015 by the American Society for Surgery of the Hand. All rights reserved.) Key words Angulation, fifth metacarpal neck fracture, Jahss maneuver, reduction Kirschner wire, percutaneous pinning.

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Surgical Technique

pneumatic tourniquet control. The surface anatomy of extensor digiti minimi is marked with a pen. A 2-mm Kirschner wire is secured to a powered drill. There are 2 principles for wire placement (Fig. 2A, B). First, the skin insertion point is selected at the ulnar border of the extensor digiti minimi. The tendon is easily palpated as the patient actively extends the little finger. Injury or transfixion of the tendon must be avoided. Second, the Kirschner wire is tilted approximately 10 ulnarward in the dorsovolar sagittal plane. Under fluoroscopic guidance, the operator holds the unpowered drill and inserts the reduction Kirschner wire manually into the dorsal fracture line of the metacarpal (Fig. 3A). A feeling of slight resistance indicates that the wire has traversed the fracture line. If the fracture line cannot be negotiated precisely, the wire is simply driven to engage into the palmar cortex of the metacarpal head but not to injure the articular surface (Fig. 3B, C). The drill is then disengaged (Fig. 3D). The reduction Kirschner wire is left in place and serves as a lever (Fig. 4). Digital leverage is applied to reduce the fracture (Fig. 5A). If rotational deformity persists, it can be corrected with the MCP joint flexed at 90 , as described by Jahss.4 We use fluoroscopy to check the accuracy of the reduction (Fig. 5B, C). Maintaining reduction, the assistant transfixes the metacarpal head with 2 Kirschner wires into the fourth metacarpal. An additional wire is used to transversely penetrate the fifth and fourth metacarpals proximal to the fracture. The wires are left protruding above the skin. Care is taken not to injure the dorsal branch of the ulnar nerve that runs a course on the dorsoulnar aspect of the fifth metacarpal. Once satisfactory reduction and pin seating are

FIGURE 1: Radiograph showing fifth metacarpal neck fracture.

SURGICAL TECHNIQUE The surgeon uses a lateral radiograph to evaluate the fracture angulation of the fifth metacarpal. The operation is performed under local anesthesia without

FIGURE 2: A The extensor digiti minimi is marked. B Insertion of the reduction Kirschner wire is tilted approximately 10 ulnarward.

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FIGURE 3: Reduction Kirschner wire insertion. A The wire is inserted into the dorsal fracture line. B Passing through and out the palmar cortex of the metacarpal head. C Lateral view. D Insertion is completed.

confirmed radiographically, the reduction wire is removed (Fig. 6A, B). POSTOPERATIVE MANAGEMENT After surgery, an orthosis protects the hand for 2 days. Active but non-resistive range of motion of the digits is started on the third postoperative day. Pin care and a dressing change are done every 3 to 5 days. Radiographs confirm bone healing with callus formation. Clinical healing is monitored by fracture tenderness. Because the wires do not block motion of the fifth MCP joint, their early removal is unnecessary unless pin track infection develops. At a mean of 8 weeks (range, 6e10 wk), the Kirschner wires are removed and passive range of motion is allowed. We err on the side of leaving the wires in for a longer time. Before pin removal, showers are allowed with the hand wrapped in a dry towel and then in a plastic bag. CASES From January 2010 to May 2012, we treated 85 hands in 85 patients with fifth metacarpal neck fracture with the J Hand Surg Am.

FIGURE 4: Diagram showing that reduction is completed.

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FIGURE 5: A The Kirschner wire is pushed for reduction. B Posteroanterior view showing the fracture is completely reduced. C Lateral view.

Surgical Technique FIGURE 6: The fracture is fixed with 3 wires. A Posteroanterior view. B Lateral view.

apex dorsal angulation was corrected to within 3 of normal and rotational deformity was completely corrected in all of 76 cases. No open reduction was required. Fragmentation potentially resulting from the reduction maneuver did not occur. Bone healing was defined a bridging callus noted on all cortices on 3 views and no focal tenderness. All patients achieved radiographic healing at a mean of 7 weeks (range, 4e14 wk). Mean follow-up was 26 months (range, 24e27 mo). At the final follow-up, bony prominence at the fracture site was noted in 8 hands. Extensor lag was calculated as maximal extension on the opposite site minus that on the injured side. In this cohort, 56

percutaneous joystick technique followed by transverse percutaneous pinning. Nine patients were excluded because of incomplete follow-up, which left 76 study patients. Mean age at surgery was 36 years (range, 18e56 y); there were 72 men and 4 women. Injuries resulted from punching (n ¼ 32), sports activities (n ¼ 29), and road traffic accidents (n ¼ 15). The dominant hand was involved in 64 patients. All patients had an apex dorsal angulation (mean, 63 ; range, 45 to 90 ). The mean time interval between the injury and the operation was 6 days (range, 0e14 d). An independent hand surgeon who was not one of the treating doctors performed all assessments. The J Hand Surg Am.

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TABLE 1.

Patient Outcomes Injured Side

Opposite Side

Mean

Range

Mean

Range

105

80e125

108

86e133

Fifth MCP joint extension-flexion arc (degrees)

4

Actual extensor lag (degrees) Pinch strength of thumb to little finger, kg Grip strength, kg

0e25

2.14

1.05e2.89

2.28

1.14e2.85

42

16e48

48

17e51

5

5e6

Overall hand function Activities of daily living

5

5e6

Work

25

24e25

Pain

25

23e25

Appearance

5

3e6

Satisfaction

6

6e7

The strength scores of the injured hand are modified on the premise that the pinch strength of thumb to little finger was 5% and grip strength was 6% higher at the dominant side compared with the nondominant side.

patients had no extensor lag, 14 had lags of 1 to 10 , 4 had lags of 11 to 20 , and 2 had greater than 20 with a mean extensor lag of 4 (range, 0 to 25 ). To exclude any discrepancy between dominant and nondominant hand strength, there was 5% reduction in pinch strength of thumb to little finger on the dominant side and 6% reduction in grip strength on the dominant side.10,11 Thus, the mean pinch strength of thumb to little finger and grip strength were 2.14 kg (range, 1.05e2.89 kg) and 42 kg (range, 16e48 kg), respectively. Measurements on the opposite side were 2.28 kg (range, 1.14e2.85 kg) and 48 kg (range, 17e51 kg), respectively. Table 1 shows the active extensionflexion arc of the fifth MCP joint. Based on the Michigan Hand Outcome Questionnaire,12 72 patients (95%) were satisfied with the appearance of the hand and 4 patients sometimes felt uncomfortable with its appearance.

rare, such bone shortening may not be restored using our technique although the angulation has been completely corrected. Thus, some degree of extension lag may persist postoperatively. Extension lag may result from extensor adhesions, bony prominence at the fracture site, or metacarpal shortening. Prominence at the fracture site from exuberant ossification may result in a visible bump. When fixing the fracture, placement of 2 wires in a transfixing fashion minimizes loss of reduction postoperatively and prevents rotation around the fulcrum of a single wire. With experience and improved manipulation skills, radiation exposure is reduced. COMPLICATIONS Postoperatively, superficial infection around the pin track of the fixation wires was observed in 2 patients, which resolved with pin care.

PEARLS AND PITFALLS In our experience, a Kirschner wire 2 mm in diameter is most appropriate for this reduction maneuver. During insertion of the reduction wire, care is taken not to injure the dorsal branch of the ulnar nerve, the extensor and flexor tendons, or even the palmar nerves. When reducing the metacarpal head, over- or under-reduction must be avoided. We think that loss of metacarpal length resulting from this manipulation is less likely to happen. However, bone loss and comminution resulting from the original injury may be present at the dorsum of the metacarpal. Although J Hand Surg Am.

REFERENCES 1. Jupiter JB, Goldfarb CA, Nagy L, et al. Posttraumatic reconstruction in the hand. Instr Course Lect. 2007;56:91e99. 2. Altizer L. Boxer’s fracture. Orthop Nurs. 2006;25(4):271e273. quiz 274e275. 3. Zhang X, Liu Z, Shao X, Wang L, Huang X, Zhu H. Palmar opening wedge osteotomy for malunion of fifth metacarpal neck fractures. J Hand Surg Am. 2013;38(12):2461e2465. 4. Jahss SA. Fractures of the metacarpals: a new method of reduction and immobilization. J Bone Joint Surg Am. 1938;20: 178e186. 5. Strauch RJ, Rosenwasser MP, Lunt JG. Metacarpal shaft fractures: the effect of shortening on the extensor tendon mechanism. J Hand Surg Am. 1998;23(3):519e523.

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Michigan Hand Outcomes Questionnaire domains

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9. Kural C, Alkas¸ L, Tüzün S, et al. Anger scale and anger types of patients with fifth metacarpal neck fracture. Acta Orthop Traumatol Turc. 2011;45(5):312e315. 10. Thurston AJ. Pivot osteotomy for the correction of malunion of metacarpal neck fractures. J Hand Surg Br. 1992;17(5):580e582. 11. Crosby CA, Wehbe MA, Mawr B. Hand strength: normative values. J Hand Surg Am. 1994;19(4):665e670. 12. Chung KC, Pillsbury MS, Walters MR, et al. Reliability and validity testing of the Michigan Hand Outcomes Questionnaire. J Hand Surg Am. 1998;23(4):575e587.

6. King JC, Beckenbaugh RD. Traction reduction and cast immobilization for the treatment of boxer’s fractures. Tech Hand Upper Extremity Surg. 1999;3(3):174e180. 7. Mohammed R, Farook MZ, Newman K. Percutaneous elastic intramedullary nailing of metacarpal fractures: surgical technique and clinical results study. J Orthop Surg Res. 2011;19(6):37e42. 8. Trevisan C, Morganti A, Casiraghi A, Marinoni EC. Lowseverity metacarpal and phalangeal fractures treated with miniature plates and screws. Arch Orthop Trauma Surg. 2004;124(10): 675e680.

Surgical Technique J Hand Surg Am.

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Reduction of fifth metacarpal neck fractures with a Kirschner wire.

This article reports on a percutaneous joystick technique for reduction of fifth metacarpal neck fractures. The technique was performed in 76 hands. R...
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