Median nerve neuropathy after flexor pollicis longus tendon reconstruction: A case report.

BACKGROUND: To treat flexor pollicis longus (FPL) muscle function loss, the 4th flexor digitorum superficialis (FDS) to the FPL tendon transfer is preferred as a reconstruction method. Various complications can occur during transfer. However, median nerve neuropathy has not been reported yet. We present a case of median nerve neuropathy caused by irritation of suture knots of the 4th FDS to the FPL tendon transfer with a review of the literature.

CASE SUMMARY: A 52-year-old male patient presented with paresthesia along median nerve distribution of right hand after tendon transfer. He complained of right thumb flexion limitation due to FPL function loss so authors performed the 4th FDS to FPL transfer using Pulvertaft weave technique. FPL function loss was due to adhesion resulting from repeated surgery of radius shaft. He had a history of radius shaft open fracture 9 years ago and nonunion 7 years ago. During surgery, FPL muscle was severely adhered and indistinguishable. However, tendon continuity remained intact. After tendon transfer, he experienced paresthesia along median nerve distribution upon movement of thumb. He was diagnosed with median nerve neuropathy caused by irritation of tendon suture knots. Exploration was then performed. The median nerve was irritated by suture knots of transferred tendon. Thus, knots were removed. Twelve months later, he demonstrated thumb flexion of 80°. Additionally, median nerve neuropathy symptoms fully resolved.

CONCLUSION: Median nerve neuropathy can occur after tendon transfer from irritation of suture knots. Covering knots using surrounding tissue is recommended.