Flexor Pollicis Longus Rupture in a Scaphoid Nonunion: A Case Report

Area of Science:

• Orthopedic Surgery
• Hand Surgery
• Musculoskeletal Research

Background:

• Scaphoid nonunion can lead to rare complications such as flexor pollicis longus (FPL) tendon rupture.
• Scaphoid nonunion advanced collapse (SNAC) arthritis may present asymptomatically.
• Tendon abrasion on bony nonunion fragments is a potential mechanism for rupture.

Observation:

• A 70-year-old woman presented with FPL tendon rupture due to abrasion on a long-standing, asymptomatic scaphoid nonunion.
• Surgical findings included sharp, mobile volar scaphoid osteophytes.
• The patient had asymptomatic SNAC arthritis associated with the nonunion.

Findings:

• Surgical intervention involved excision of osteophytes, wrist capsule repair augmented with a vascularized fat flap, and FPL reconstruction using a palmaris longus graft.
• The vascularized fat flap provided a smooth gliding surface for the FPL tendon.
• The patient achieved a functioning FPL tendon with no further wrist surgery required.

Implications:

• This case highlights a rare but significant complication of scaphoid nonunion.
• Surgical management focused on restoring FPL function and preventing re-rupture.
• A combined approach of osteophyte debridement, wrist stabilization, and tendon reconstruction can yield successful outcomes.