Plantarflexion torque following reconstruction of Achilles tendinosis or rupture with flexor hallucis longus augmentation

Nine patients treated surgically for Achilles tendon rupture (7 patients) or tendinosis (2 patients) with primary repair or debridement and augmentation with the flexor hallucis longus muscle-tendon unit were evaluated at a mean of 19 months postoperative. Subjective evaluation revealed a high level of satisfaction. All patients returned to work and only two patients reported limitation in their recreational activities. The mean post-operative AOFAS Ankle-Hindfoot Score was 90 points. Four patients reported mild occasional pain and one patient complained of moderate daily pain. Motion assessment showed a 20% increase in the hallux MTP dorsiflexion compared to the non-operative side (p = 0.045). No difference in ankle motion was noted. Cybex II+ dynamic evaluation of plantarflexion peak torque was complete on both extremities. The torque deficit on the reconstructed extremity was 20% (p = 0.01) at 120 degrees per second and 26% (p = 0.003) at 30 degrees per second. There is no significant difference between the torque deficit recorded for patients with Achilles rupture and those with Achilles tendinosis. A trend toward improved torque production with longer follow up was observed.