Malrotation in Nonarticular Phalanx Fractures

34 Malrotation in Nonarticular Phalanx Fractures

Mark S. Rekant

34.1 Patient History Leading to the Specific Problem

A 28-year-old female bank teller presents with continued difficulty making a right fist and a “crooked finger.” She reports having a hand fracture 14 months ago during a motor vehicle collision for which she required an extensive hospitalization. The fracture was treated in a splint for 4 weeks at the time followed by occupational therapy. Despite therapy, the patient complains that her finger gets in the way of the other fingers when grabbing items.

34.2 Anatomic Description of the Patient’s Current Status

The patient has a normal-appearing hand without scars or wounds. There are no areas of tenderness. Upon making a fist, there is scissoring noted on the right ring finger that limits full flexion to the distal palmar crease with rotational malalignment (Fig. 34.1). The patient has full passive range of motion. Total active motion (TAM) of the right ring finger measures 226 degrees (left ring finger 260 degrees).

34.3 Recommended Solution to the Problem

Surgical management of proximal phalanx fractures is challenging. Current described techniques of direct repair maybe complicated by ongoing stiffness, pin infection/loosening, deep infection, hardware irritation, extensor lag, malunion, and nonunion. The flexion force of the interossei insertion on the proximal fragment and the extension force of the central slip on the base of the middle phalanx often lead to an apex volar deformity. Other times, fracture pattern and injury mechanism may cause malrotation at the fracture site. Despite appropriate management, malrotation of both nonoperative and operatively treated proximal phalanx fracture may occur.

Rotational malunion is often a disabling complication of proximal phalanx fractures. After swelling and pain subside, and active motion is advanced, subtle malunion on radiographs may produce a pronounced malrotation deficit noted most in mid-fist. If active and passive motion of the digit is within acceptable range, bypassing the zone of injury with a metacarpal osteotomy to correct the malrotation is a good option.

34.3.1 Recommended Solution to the Problem

Prevention is the best treatment. Provide passive motion or observe early active motion when possible to check for malrotation after proximal phalanx fractures.

If operative intervention is required, consider wide-awake or local anesthesia/monitored anesthesia care. Patients can then make a fist in the operative suite to ensure rotation is correct and fixation is adequate to allow for some protected early motion.

Away from the tight soft-tissue confines of the proximal phalanx, an osteotomy at the metacarpal metadiaphyseal region provides for better bony fixation and less soft-tissue problems.

34.4 Technique

Prior to entering the operating theater, both hands of the patient are evaluated critically for subtleties in rotation. Critically evaluating the angulation and position of the nail plate through active range of motion of both the injured and normal hands helps guide the correction necessary.

The patient is taken to the operating theater and placed in the supine position with a hand table. Using local, regional, or general anesthesia with sedation and an arm tourniquet, the arm is prepped and draped. The carpometacarpal (CMC) joint of the affected joint is palpated, and fluoroscopy can be used to confirm location. Beginning at the CMC joint a 4-cm skin incision is made extending in line with the metacarpal of the affected digit. Extensor tendons are identified and retracted, while sharp dissection is used to expose the metadiaphysis of the metacarpal in a subperiosteal fashion. Once exposed, care is used to further expose the base and diaphysis of the metacarpal in preparation for plate placement.

After proper exposure, a T-style 2.4-mm plate (2.0-mm plate in smaller females) is utilized to allow for two-screw fixation both proximal and distal to the osteotomy (Fig. 34.2a). The plate is applied to the intact metacarpal using only the two screws in the metacarpal base and fluoroscopy is used to confirm placement and to mark the osteotomy site. A 0.062-inch K-wire is placed distal to the plate to serve as a rotation lever and guide (Fig. 34.2b).

After confirmation, the plate is removed and the transverse osteotomy is performed using a saw blade with copious amounts of irrigation. It is helpful to score and mark the metacarpal with ink longitudinally prior to the osteotomy to recall the initial bony alignment. The 0.062-inch K-wire is used to rotate the metacarpal, helping dial in the correct rotation (Video 34.1). With satisfactory correction, a separate 0.045-inch K-wire is placed from an adjacent metacarpal into the distal segment to maintain the correction and serve as provisional fixation of the osteotomy. To further confirm correct rotation, use wrist motion and pressure on the proximal muscle bellies to check for a normal cascade and rotation with tenodesis or have the patient gently move their fingers if using wide-awake surgery. After securing the proximal plate using the predrilled holes, the distal holes are filled using bicortical cortical screws in a compression technique. Radiographs are used to confirm proper fixation and the wound is then irrigated and closed (Fig. 34.3). The hand is splinted in the intrinsic plus position. Protected motion is started after the first follow-up visit and the patient is weaned from a splint at 4 to 6 weeks.

The metacarpal 0.062-inch K-wire is essential to evaluate the true bony correction. Manually rotating the finger or using a wire further distally in the phalanx will rotate through some articulation where soft tissues may account for some rotation. This will underestimate the true correction.

There is a limit to correction. With maximum rotation of the metacarpal, a 20-degree correction can be achieved with the exception of the small finger, in which a 30-degree pronation deformity can be corrected (rotates away from the scaphoid tubercle prior to correction). The deep metacarpal transverse ligaments limit rotation, but we have not seen problems with flexion limitation, unsatisfactory correction, or saddle syndrome in patients after correction.

Dec 2, 2021 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Malrotation in Nonarticular Phalanx Fractures
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