赤坂 朋代

PURPOSE: This study aimed to introduce a novel technique using the extensor pollicis brevis and extensor indicis proprius tendons as power sources for thumb opposition reconstruction in cases of severe carpal tunnel syndrome (CTS) associated with thenar muscle atrophy. Furthermore, the efficacy of this novel method and the traditional Camitz technique was compared. METHODS: Patients with severe CTS and thumb opposition dysfunction who underwent surgery using the novel technique (n = 7 and 9 surgeries) or the Camitz technique (n = 8 and 8 surgeries) were included in the analysis. The pre- and postoperative palmar abduction angle, thumb-ring finger opposition angle, and Kapandji score were assessed. The repeated measures analysis of variance and the Mann-Whitney U test were used for statistical analysis. RESULTS: The novel technique was associated with a significant postoperative improvement in palmar abduction angle, thumb-ring finger opposition angle, and Kapandji score. In particular, the thumb-ring finger opposition angle of patients who underwent surgery using this technique was superior to that of patients who underwent surgery using the Camitz technique. Therefore, the novel technique was highly effective in improving thumb pronation. CONCLUSION: The novel technique using the extensor pollicis brevis and extensor indicis proprius tendons is promising for thumb opposition reconstruction in severe CTS cases. Unlike the traditional Camitz technique, this approach promotes stable thumb opposition function without requiring a pulley, thereby yielding satisfactory outcomes. Nevertheless, further studies with a larger sample size should be conducted to validate these findings. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic 4; Surgical technique.

It is important to know the relationship between flexor tendon traction force and applied finger flexion force generated during the rehabilitation of trigger finger. However, there has been no report on this relationship using the Jamar dynamometer in clinical practice and cadaveric study. Therefore, the purposes of this cadaveric study were to measure the value of flexion force when pulling a tendon via the method used in clinical practice and to investigate the relationship between the traction force of the flexor tendon and the flexion force of the finger output based on the Jamar dynamometer. In this study, each finger of a fresh-frozen cadaver was pulled, and the finger flexion force was measured with the Jamar Plus+ Digital Hand Dynamometer （Performance Health, Chicago, IL, USA）. There was a strong first-order correlation between the flexor tendon traction force and the finger flexion force, and the value of the finger flexion force［N］divided by the flexor tendon traction force［N］was 0.195-0.321. Under the same flexor tendon traction force, the exerted finger flexion force was in the following order: middle finger, index finger, ring finger, and little finger（maximum to minimum）. It is important to consider these findings when performing rehabilitation of trigger finger.