Salter-Harris III fractures are intra-articular and usually not amenable to closed reduction (Fig. 32-1). Salter-Harris III fractures of the proximal phalanx of the thumb represent the pediatric equivalent of the adult “gamekeeper’s thumb” (6,10,11,12). Given the strength of the ulnar collateral ligament relative to the physis, a radially directed force to the metacarpophalangeal (MCP) joint will typically result in an avulsion fracture of the proximal phalangeal epiphysis (11). Displaced Salter-Harris III fractures of the proximal phalanx of the thumb require open reduction and internal fixation to restore articular congruity, joint stability, and physeal alignment (6).

Patients and/or parents will describe a radially directed force imparted to the thumb, typically during sports participation or a fall. Physical examination reveals tenderness and swelling at the ulnar base of the proximal phalanx. Laxity with careful radial stress may be elicited. Gentle examination techniques are required in the acute setting, particularly in the younger, anxious child. Plain anteroposterior (AP) and lateral radiographs of the thumb will confirm the diagnosis. In cases in which there is laxity with radial stress and negative radiographs, one can conclude that there has been an injury to the ulnar collateral ligament of the thumb MCP joint. MRI scan should be confirmatory.

Patients are positioned supine with the affected extremity placed on a radiolucent hand table (Fig. 32-2). A well-padded tourniquet is placed on the upper brachium, and the entire extremity is prepped and draped after the induction of general anesthesia. Regional anesthesia may be utilized as appropriate. The limb is exsanguinated with an Esmarch bandage, and the tourniquet is raised to
250 mm Hg. An incision is made over the dorsal-ulnar aspect of the thumb MCP joint (Fig. 32-3). Subcutaneous dissection is performed in line with the skin incision, protecting the radial sensory nerve. The adductor pollicis fascia is released from its insertion on the extensor tendon. As the ulnar collateral ligament is usually intact, the MCP joint should be exposed distally through the fracture site. The ligament should not be divided.

After cleaning and irrigating the fracture site, the avulsed epiphyseal fracture fragment is carefully reduced. Two parallel or slightly divergent smooth K-wires are placed into the reduced epiphyseal
fragment, across the fracture site, and into the opposite radial cortex. Intraoperative fluoroscopy is helpful to confirm anatomic reduction and appropriate placement of the wires (Fig. 32-3). If the ulnar collateral ligament is noted to be lax or avulsed, its insertion may be advanced or repaired with fine absorbable sutures to the underlying periosteum. The tourniquet is released and adequate hemostasis achieved. We prefer to bend and cut the wires superficial to the skin. A layered closure is performed, carefully reapproximating the adductor pollicis fascia. Care must be made to avoid suturing the extensor mechanism to the underlying joint capsule, which may interfere with thumb flexion. The skin is closed with 4-0 absorbable suture in a subcuticular fashion. A bulky dressing and thumb spica cast is then applied and usually bivalved.

Patients remain in the thumb spica cast for 4 to 6 weeks until radiographic evidence of fracture healing. After this time, the cast is discontinued and the smooth wires are removed, usually in the office setting without the need for anesthesia. Range-of-motion and strengthening exercises are begun with a home program. A protective splint for potential traumatic activities is utilized until full motion and strength are achieved, which generally occurs by 8 to 12 weeks postoperatively. At that time, unrestricted activities are performed.