• INTRODUCTION
    • Thenar muscle atrophy is a common finding in long-standing severe carpal tunnel syndrome (CTS). Combination of carpal tunnel release and Camitz opponensplasty has been used to treat severe CTS with thenar muscle atrophy. Camitz opponensplasty is beneficial for abduction, but provides little benefit to thumb flexion and pronation. This problem could be overcome by the use of a pulley.
  • MATERIALS AND METHODS
    • Twelve cases of long-standing CTS with severe thenar muscle atrophy in 11 patients were investigated. They were treated with the modified Camitz opponensplasty using a pulley at the ulnar side remnant of the flexor retinaculum at the time of carpal tunnel release. Outcome was assessed by clinical grade of thenar muscle atrophy, degree of thumb opposition and the patient's satisfaction.
  • RESULTS
    • The average grade of thenar muscle atrophy improved from grade 3 pre-operatively to grade 0.83 at the last follow-up. Mean maximal palmar abduction improved from 3.6 to 6.8 cm, and spatial rotation improved from 54 degrees to 83 degrees . Kapandji tip opposition changed from 65 to 85% symmetry at the last follow-up. All 11 patients were 'very satisfied' or 'satisfied' with the outcome.
  • CONCLUSION
    • Modified Camitz opponensplasty is a simple procedure that provides immediate improvement of thenar function. Palmar flexion and pronation can be further improved by addition of a pulley.