Surgery is indicated to restore normal push-off power. Selection of the specific surgical procedure used is determined by analyzing the mechanism of injury, duration of time from the initial injury, and the quality of the tissues. The longer the duration from the initial injury, the less likely a primary end-to-end repair can be performed. In my experience, primary end-to-end repair can be successfully achieved up to 3 months after injury.

Connective tissue disease such as rheumatoid arthritis, diabetes mellitus, obesity, autoimmune disorders, and malnutrition may adversely affect the success of end-to-end repair and may necessitate augmentation. Local factors that make the repair weaker or contribute to postoperative wound problems include ischemia due to peripheral vascular disease, excessive scarring or adhesions from previous surgery, previous infection, and venous insufficiency.

Contraindications for surgery include severe peripheral vascular disease and concomitant medical conditions precluding anesthesia.

The diagnosis is made by reviewing the patient’s history and performing a physical examination. The usual history of an acute rupture is acute onset of pain and inability to rise onto the toes. At the time of rupture, patients often report the sensation of being struck in the calf from behind and experience immediate pain and weakness. The pain may increase as hematoma formation occurs. Patients with systemic connective tissue disorders such as rheumatoid arthritis may relate a more gradual onset, with Achilles tendinosis pain and eventual loss of the ability to rise onto the toes. Tendon rupture from progressive degenerative tendinosis also presents with an insidious course. On examination, active but weak plantarflexion is maintained because of the extrinsic toe flexors, posterior tibial, and peroneal muscles. Misdiagnosis of the time of the rupture can occur in up to 20% of cases. Initially, there may not be an obvious tendon defect, but with time, the ends of the ruptured tendon separate, and the overlying skin conforms to the posterior leg, appearing as a hatchet-type defect. It may appear that there is an overgrowth of the posterior calcaneus
(Fig. 44.1). The Thompson test (i.e., calf squeeze test) result is positive but does not cause as much pain as an acute injury.

The patient with a tendon rupture from progressive degenerative tendinosis presents with an insidious course with progressive thickening of the tendon, progressive lengthening of the tendon, decreased function in push-off, and increased pain. A defect is not evident unless an acute or chronic traumatic rupture occurs. In general, the tendon is markedly thickened and tender to palpation.

Radiographs should be obtained to exclude avulsion of the posterior tuberosity of the calcaneus (Fig. 44.2), bony deformities, and calcification of the tendon. Magnetic resonance imaging (MRI) may be helpful in the uncertain diagnosis of an Achilles tendon rupture and chronic tendinosis
(Fig. 44.3). It is most helpful in the sagittal plane to determine the length of tendon injured and to anticipate the type of surgical procedure needed (10).

The rupture usually occurs 2 to 6 cm from the calcaneal insertion, which is the most avascular region of the tendon. If clinical examination or MRI indicates the defect is less than about 3 cm and if the injury has occurred within the past 3 months, direct end-to-end repair is often possible. If the gap is larger than 3 cm after scar tissue debridement, then V-Y lengthening, Lindholm turn-down procedure, or flexor hallucis longus (FHL) tendon transfer may be considered to close the gap if the remaining tendon tissue is healthy. If the remaining tendon tissue is not healthy and has chronic tendinosis, augmentation with transfer of the FHL tendon or hamstring can be used.