SLR - October 2016 - Kayla O’Malley

Direct Repair of Chronic Achilles Tendon Ruptures Using Scar Tissue Located Between the Tendon Stumps

Reference: Yasuda T, Shima H, Mori K, Kizawa M, Neo M. Direct Repair of Chronic Achilles Tendon Ruptures Using Scar Tissue Located Between the Tendon Stumps. J Bone Joint Surg Am. 2016 Jul 20;98(14):1168–75.

Scientific Literature Review

Reviewed By: Kayla O’Malley, DPM
Residency Program: St. Vincent Hospital/WMC

Podiatric Relevance: There are several reported surgical procedures for the chronically ruptured Achilles tendon. Most of these procedures involve resection of scar tissue and reconstruction with autologous or allografts. These procedures can take more time and can come with the challenges of donor site morbidity. The histology of healing tendon has shown fibrovascular tissue with thickened collagen fibers. This study showed that the scar tissue between tendon stumps was also made of dense collagen fibers with fibroblasts. These results suggested that the scar tissue could be used in the primary repair of the chronically ruptured Achilles tendon.

Methods: Thirty consecutive patients with symptomatic chronic Achilles tendon ruptures underwent repair. Inclusion criteria was disability with activities of daily living, asymmetric gait due to plantar flexion weakness, unable to perform a single heel-rise on the affected limb and failed conservative methods. All patients had a rupture for > 4 weeks. The rupture was diagnosed by positive Thompson test, inability to perform single heel-rise on affected limb and preoperative MRI. Exclusion criteria were Achilles tendon rerupture, a previous surgical procedure on the affected limb and corticosteroid therapy for other illnesses. Patients had to complete a two-year follow up. The mean age was 52.7 years old. There were 16 men and 14 women in this study. Six patients had hypertension, five patients had hyperlipidemia and three patients had diabetes. Two patients were smokers. Three competitive athletes were included in the group. The surgical procedure was performed in a prone position with a posteromedial longitudinal incision. The gap between the native tendon stumps averaged 43.3mm in length and was filled with scar tissue. The triceps surae was released with blunt dissection of the adhesions proximally. The middle part of scar tissue between the tendon ends was resected. After resection, they confirmed the approximation of the proximal and distal ends of the tendon was possible with 20 to 30 degrees of plantar flexion. Repair was performed with two nonabsorbable suture using Krackow stitch. The stumps with interposed scar tissue were then sutured together in the 20 to 30 degrees of plantar flexion. The paratenon was then repaired. Postoperative treatment consisted of short leg cast with the ankle held in 20 degrees of plantar flexion for two weeks. At three weeks, the cast was removed and an AFO with three heel wedges used. Partial weightbearing and range of motion exercises were encouraged at this time. One heel wedge was removed each week after. At six weeks, the AFO was removed. At seven weeks, double heel rises were encouraged. Return to sports was allowed at four to five months after the surgery.

Results: Preoperative and postoperative outcomes were measured using the Achilles Tendon Total Rupture Score (ATRS) and AOFAS ankle-hindfoot score. Patients also underwent pre- and postoperative functional measurements and MRI imaging. A piece of scar tissue was taken and sent to histology for review on each patient in the study. The AOFAS scores were 82.8 preoperatively and 98.1 postoperatively. The mean postoperative ATRS was 92. At the last follow-up, none of the patients has experienced reruptures or difficulties with gait. Two patients still could not perform a single heel rise on the affected limb. The athletes returned to their preinjury level of sports. Preop MRI showed that 22 Achilles tendons were thickened with diffuse intratendinous high-signal alterations. Eight Achilles tendons showed thinning on MRI. Postop MRI showed fusiform shaped tendon thickening with homogenous low-signal alterations of the tendon in all 30 patients. All scar tissue histologically showed dense collagen fibers with numerous fibroblasts.

Conclusion: This study showed that shortening of tissue between two tendon ends in the chronic Achilles rupture includes healing scar tissue. This tissue can be helpful in the direct end-to-end repair without having to use autograft or allograft. This is an effective way to treat the neglected Achilles rupture.

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