Bilateral achilles tendon ruptures in a patient with ochronosis: a case report

We report the case of a 67-year-old man with ochronosis who had bilateral Achilles tendon ruptures. We reconstructed the Achilles tendon using pull-out wiring for the right side and an anchoring system for the left side, and reinforced the repair site using the peroneus brevis tendon for both sides. He could walk without a cane at 3 months postoperatively. Tendon ruptures in patients with ochronosis should be treated as pathologic ruptures because histologic examination reveals that both ends of the ruptured tendon and the insertion site at the calcaneus have extensive black pigment depositions where homogentisic acid and its metabolites have accumulated, and there are no normal collagen bundles present. Even if an Achilles tendon rupture is clinically diagnosed as an acute injury, the ruptured Achilles tendon should be primarily repaired and reinforced with autologous tissue because there are a few viable cells at the ruptured site, and because the tendon ruptures mainly at the insertion site of the calcaneus. Although this is a preliminary report, the short-term result is good and the reconstructed sites have showed no rerupture.