Standard versus over-tensioning in the transfer of extensor indicis proprius to extensor pollicis longus for chronic rupture of the thumb extensor

Abstract

The purpose of this study was to evaluate the functional outcomes of the over-tensioning technique compared with those of the standard tensioning technique in the transfer of extensor indicis proprius (EIP) to extensor pollicis longus (EPL) for the chronic rupture of the thumb extensor. Data were collected from patients who underwent tendon transfer using EIP between March 2003 and August 2011. 23 were treated with the standard tensioning technique and 25 patients (Group B) with the over-tensioning technique. While standard tension was maintained with the thumb in full extension and the wrist in 30° of flexion, over-tension was maintained with the thumb in full extension and the wrist in the neutral position. All patients were assessed for total range of motion, elevation and flexion deficit, the thumb grip and pinch strength, and the thumb and the index extension strength compared to the unaffected side, EIP-EPL evaluation as suggested by Lemmen et al. and Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH). Group A: total range of motion 115°, elevation deficit 2.0 cm, combined flexion deficit 1.0 cm, thumb extension strength 75%, thumb grip strength 91%, and pinch strength 87%. Functional outcomes were 13 excellent, 6 good, 3 fair, and 1 poor. Median DASH score was 21.3 points. Group B: total range of motion 125°, elevation deficit 1.0 cm, combined flexion deficit 1.5 cm, thumb extension strength 85%, thumb grip strength 88%, and pinch strength 83%. Functional outcomes were 16 excellent, 7 good, 2 fair, and 0 poor. Median DASH score was 19.8 points. There are significant differences in the range of motion, elevation deficit, and extension strength of thumb between the two groups (p=.001, p=.001, and p=.028, respectively). While the functional outcomes of both groups were favorably acceptable in a majority of the patients, there were significant differences in aspects of range of motion, elevation deficit, and strength of the thumb between both groups. Case-control study, Level III.