Influences of the protected passive mobilization interval on flexor tendon healing. A prospective randomized clinical study.

A prospective multicenter clinical study was carried out to determine whether improved tendon gliding could be achieved with greater durations of daily passive-motion rehabilitation after flexor tendon repair. Fifty-one patients were placed randomly into two controlled passive-motion protocols. Group 1 patients received greater intervals of passive-motion rehabilitation using a continuous passive-motion device. Group 2 patients were treated with a traditional early passive-motion protocol for tendon rehabilitation. For Group 1 patients, the mean interval of controlled motion rehabilitation was 75 hours a week, and the mean number of cycles was 12,000. For Group 2 patients the mean interval of controlled passive motion was four hours a week, and the mean number of cycles was 1000. The minimum follow-up time was six months (mean, 10.8 months). Using Strickland and Glogovac's formula, the mean active motion for digits in Group 1 was 138 degrees +/- 6 degrees. Mean motion for tendons in Group 2 was 119 degrees +/- 8 degrees. The difference between Groups 1 and 2 was statistically significant. The effect of the number of tendons injured per digit within each group was not significant. The data from this experiment indicate that the duration of the daily controlled motion interval is a significant variable insofar as postrepair flexor tendon function is concerned.