Prognostic factors for digital range of motion after intrasynovial flexor tendon injury and repair: Long-term follow-up on 273 patients treated with active extension-passive flexion with rubber bands.

STUDY DESIGN: Observational cohort study.

INTRODUCTION: Investigating prognostic factors using population-based data may be used to improve functional outcome after flexor tendon injury and repair.

PURPOSE OF THE STUDY: The aim of this study is to investigate the effect of concomitant nerve transection, combined flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendon transection and the age of the patient, on digital range of motion (ROM) more than 1 year after FDP tendon transection and repair in zone I and II.

METHODS: Two hundred seventy-three patients with a total of 311 fingers admitted for FDP injury in zone I and II were treated with active extension-passive flexion with rubber bands and followed for at least 1 year. We compared outcome by evaluating digital mobility using Strickland's evaluation system.

RESULTS: At 12 months 72% of patients aged > 50 had fair or poor ROM compared to 17% of patients aged 0-25 years. At 24 months the results for patients aged > 50 had improved to 33% with fair or poor ROM, whereas no improvement had occurred for patients aged 0-25 (17% with fair or poor ROM). Concomitant nerve transection and FDS tendon transection had no negative effects on digital mobility.

DISCUSSION: Age above 50 was significantly associated with impaired digital ROM during the first year after flexor tendon injury and repair but not at 2 years follow-up. Concomitant nerve transection and combined transection of FDP and FDS do not affect digital mobility.

CONCLUSIONS: Older patients are likely to have a slower healing process and impaired digital ROM during the first year after surgery.