Early Motion of the Ankle After Operative Treatment of a Rupture of the Achilles Tendon

Abstract & commentary

Synopsis: Early restricted motion appeared to shorten the time needed for rehabilitation and recovery from this injury.

Source: Mortensen NHM, et al. Early motion of the ankle after operative treatment of a rupture of the Achilles tendon. J Bone Joint Surg Am 1999;81:983-990.

This prospective, randomized, clinical, and radiographic study compares two different postoperative treatment regimens in the management of Achilles tendon rupture. After performing a standardized surgical repair of the ruptured Achilles tendon acutely within five hours of injury, patients were randomized to one of two postoperative treatment groups. One group, the controls, was placed in a below-the-knee plaster cast with the foot held in a moderate amount of equinus for six weeks postoperatively. Then the cast was changed and the foot was held in a neutral position for an additional two weeks. The cast was then removed and the patient was encouraged to begin weight bearing as tolerated and engaged in an unsupervised strengthening and rehabilitation program.

The second group of patients, the "early motion" group, had their ankles splinted in a moderate equinus posture for two weeks postoperatively. Then they were placed in a modified Don Joy ROM-walker brace that prevented ankle dorsiflexion beyond neutral and held the ankle in 30° of plantar flexion with an elastic band spanning the posterior aspect of the brace. In the brace, which was worn full-time for four weeks, patients were encouraged to perform active dorsiflexion exercises from 30° of plantar flexion to neutral. Thus, the device acted somewhat like a Kleinert apparatus, as used for protection of repaired flexor tendons in the hand. At six weeks postoperatively, the brace was removed and the patient was encouraged to bear weight as tolerated and, again, begun on an unsupervised strengthening and rehabilitation program.

To assess whether the surgical repair stretched out postoperatively, small wires were implanted into the surgical repair site, and postoperative x-rays were taken immediately after surgery and again at six and 12 weeks postoperatively. Patients were assessed at 12 weeks postoperatively and again at 16 months postoperatively. No patient was found to have experienced excessive lengthening of the tendon repair. The patients in the early motion group had a smaller initial loss of range of motion, returned to work and sports activities sooner, and subjectively were more satisfied with their overall result. There was, however, no difference in the amount of final strength between the two groups, as both recovered a median of 89% plantar flexion strength as compared to the uninjured side. Mortensen and colleagues conclude from this study that early restricted motion appeared to shorten the time needed for rehabilitation and recovery from this injury. They did not note any significant complications related specifically to the early motion program; however, this early, unloaded exercise program did not prevent some degree of muscular atrophy with persistent weakness of plantar flexion strength.

Comment by James D. Heckman, MD

Prolonged cast immobilization following Achilles tendon repair has been felt to be at least partially responsible for persistent calf weakness and atrophy and a prolonged course of rehabilitation. Functional treatment of other repaired flexor tendons has proven beneficial.1 Recent studies have shown similar beneficial effects of functional postoperative management of Achilles tendon rupture.2,3 This is another study designed to evaluate the effect of this methodology. The study clearly demonstrates that protected active range of motion exercises from 30° of plantar flexion to neutral will not disrupt a surgically repaired Achilles tendon. There seems to be some benefit in engaging in this early rehabilitation program as the patients return to function more quickly. Because the exercise program was not performed against resistance, the unloaded exercises did not prevent muscle atrophy to any degree.

Mortensen et al did not initiate the early range of motion program until two weeks postoperatively, during which time the patients were kept in a protective splint, I assume to allow soft tissue healing. Whether earlier active range of motion would have prevented calf atrophy or whether aggressive resistive exercises against moderate resistance, short of weight-bearing stresses, would have prevented atrophy is not known.

The study was conducted in an objective fashion and the results point to the value of a functional rehabilitation program as an integral part of the postoperative management of Achilles tendon ruptures.

References

1. Kleinert HE, et al. Primary repair of flexor tendons. Orthop Clin North Am 1973;4:865-876.

2. Carter TR, et al. Functional postoperative treatment of Achilles tendon repair. Am J Sports Med 1992;20: 459-462.

3. Mandelbaum BR, et al. Achilles tendon ruptures. A new method of repair, early range of motion, and functional rehabilitation. Am J Sports Med 1995;23: 392-395.