Results of primary extensor tendon repair in relation to the zone of injury and pre-operative outcome estimation.

INTRODUCTION: The outcome of primary extensor repair in hand surgery has been widely explored, but little systematic effort has been made to investigate the influence of the anatomical zone of tendon injury. Therefore, the aim of our study was to assess the outcome of primary extensor tendon repair with a special focus on the pre-operative state and Verdan's anatomical zones. Our hypothesis being tested was that the outcome after primary extensor repair depends on the complexity of trauma and the site of lesion.

MATERIALS AND METHODS: One hundred and seventy seven patients with 203 extensor tendon repairs were studied. After tendon repair and a 6-week protective immobilization, physiotherapy was carried out. A score proposed by Geldmacher and Schwarzbach was applied to estimate the outcome pre-operatively and to assess the results in a follow-up after a mean of 13 months. Correlations were tested between the anatomical zone of tendon injury, the pre-operative expectation and the results as considered both by the patient and the physician.

RESULTS: In Verdan's zones 1, 2, 4 and 5, excellent or good results were obtained in the vast majority of patients. Due to a higher frequency of complex injuries with concomitant soft tissue and bony injuries, the outcome was significantly worse after tendon repair in zones 3 and 6, as expected after the pre-operative estimation. In addition, a strong correlation was found for all anatomical zones between the pre-operative estimation and the outcome as judged both by the physician and the patient.

CONCLUSION: Recovery of finger function after primary extensor tendon repair depends on the complexity of trauma and the anatomical zone of tendon injury. Static splinting is an appropriate tool after primary extensor tendon repair in Verdan's zone 1, 2, 4 and 5, whereas injuries in zones 3 and 6 may demand for a different treatment regimen.