Summary

Failure of ulnar nerve subcutaneous transposition, surgical reasons and treament

Abstract

Background

Ulnar neuropathy, or primary cubital tunnel syndrome, is the second most common
nerve compression disorder affecting the upper extremity. Surgical management often
fails due to inadequate nerve decompression at key anatomical sites. This study
evaluates the failure of subcutaneous ulnar nerve transposition and identifies the
anatomical factors contributing to symptom persistence/recurrence.

Methods

We reviewed the medical records of 21 patients who underwent revision surgery for
failed subcutaneous ulnar nerve transposition performed between 2001 and 2019.
Clinical assessments included Tinel's sign, paresthesia, muscle atrophy, and
McGowan’s score. The revision involved submuscular or subcutaneous transpositions
with comprehensive decompression at multiple sites, including the arcade of Struthers,
the medial intermuscular septum, and the deep flexor-pronator aponeurosis.

Results

Intraoperative findings revealed proximal compression at the arcade of Struthers in
71.4% of patients, distal compression at the deep flexor-pronator aponeurosis in 38%,
and an intact medial intermuscular septum in 76.2%. Postoperatively, 14 patients
achieved excellent results according to Messina's criteria and 14 attained S4 on the
British Medical Research Council sensory grading scale. Overall, 90.5% of patients
were satisfied, with significant pain reduction and sensory loss improvement.

Conclusion

Inadequate decompression at key anatomical sites, like the arcade of Struthers, the
medial intermuscular septum, and the deep flexor-pronator aponeurosis, significantly
contributes to the failure of subcutaneous nerve transposition. Triceps snapping may
also be a cause of symptom persistence. Surgical approaches that address all
potential compression sites can improve outcomes. Research should focus on refining
surgical techniques that ensure complete decompression during ulnar nerve
transposition.