What is the management of mallet finger that has failed conservative management?

From the Guidelines

Surgical intervention is recommended for mallet finger that has failed conservative management, particularly when there is involvement of more than one-third of the articular surface, palmar displacement of the distal phalanx, or an interfragmentary gap of >3 mm 1. The primary surgical options include open repair with K-wire fixation, extension block pinning, or hook plate fixation.

• Surgery is typically performed under local anesthesia as an outpatient procedure.
• For open repair, a dorsal H or Y-shaped incision is made over the DIP joint, followed by direct repair of the extensor tendon to bone using suture anchors or pull-out sutures.
• K-wire fixation maintains the DIP joint in slight hyperextension for 6-8 weeks. Postoperatively, patients require immobilization for 6-8 weeks, followed by progressive range of motion exercises and night splinting for an additional 2-4 weeks.
• Physical therapy focusing on DIP joint mobility and strengthening is essential for optimal outcomes. Surgery is indicated when there is persistent extension lag greater than 20 degrees, large bony fragments (>30% of articular surface), volar subluxation of the distal phalanx, or open injuries 1. The goal of surgical repair is to directly reattach the extensor tendon or bony fragment, restoring the extensor mechanism's integrity and preventing long-term deformity and dysfunction that can lead to osteoarthritis and permanent disability.

From the Research

Management of Mallet Finger

After failed conservative management, various surgical techniques can be employed to restore the extension of the distal phalanx. The following options are available:

• Step-plasty procedure: This technique involves incising the elongated extensor tendon in a Z-like fashion and stepwise resecting it in the transverse portion of the Z 2.
• Purse-string suture: Although it has shown efficacy, it can result in significant bulging and scar formation 2.
• Tendon-bone graft: This technique involves taking a graft from the extensor carpi radialis brevis and the third metacarpal base for reconstruction 3.
• Tenodesis: This technique is particularly described in pediatric cases 2.
• Osseous extensor tendon rupture repair: In cases of fracture of the distal phalanx, open reduction and fixation is recommended, with a cerclage technique using cannulated drilling 4.

Surgical Outcomes

The outcomes of these surgical techniques have been evaluated in various studies:

• The step-plasty procedure has been shown to significantly reduce extension deficits, with an average reduction from 42 degrees preoperatively to 11 degrees postoperatively 2.
• The tendon-bone graft technique has been shown to achieve bone healing in all patients, with a mean residual extension lag of 4° at the final follow-up 3.
• The purse-string suture technique has been shown to have a slightly higher postoperative extension deficit of 15° compared to the step-plasty procedure 2.

Comparison of Surgical Techniques

The choice of surgical technique depends on various factors, including the severity of the injury and the patient's overall health. The following comparisons have been made:

• The step-plasty procedure has been shown to have better functional and aesthetic outcomes compared to the purse-string suture technique 2.
• The tendon-bone graft technique has been shown to be a useful and reliable technique for the treatment of tendinous mallet fingers after failed splinting 3.