Damage to the medial attachment of the superficial flexor tendon as it passes over the tuber calcanei can cause a lateral luxation of the tendon. The injury occurs as a result of sudden flexion of the hock, and the tendon can occasionally slip to the medial aspect of the hock. Initially, there is lameness in the limb, with local heat and swelling. Treatment involves rest for ≥3 mo, possibly with application of a cast. The lameness improves, but the horse may be left with a permanently displaced flexor tendon and a rather jerky hock action. There is usually no difficulty during fast exercise or jumping, but dressage movements may be affected. Surgical treatment (implantation of special screws to which sutures that repair the ruptured annular ligament can be anchored) has been reported in a limited number of cases. The results vary and are not likely to be favorable in larger horses.
Last full review/revision March 2012 by Stephen B. Adams, DVM, MS, DACVS; Andrew L. Crawford, BVetMed, CertES (Orth), MRCVS; James K. Belknap, DVM, PhD, DACVS; Jane C. Boswell, MA, VetMB, CertVA, CertES (Orth), DECVS, MRCVS; Peter Clegg, MA, Vet MB, PhD, CertEO, DECVS, MRCVS; Marcus J. Head, BVetMed, MRCVS; C. Wayne McIlwraith, BVSc, PhD, DSc, FRCVS, DACVS; James Schumacher, DVM, MS, DACVS, MRCVS; John Schumacher, DVM, MS, DACVS, MRCVS; Roger K. W. Smith, MA, VetMB, PhD, DEO, DECVS, MRCVS; Chris Whitton, BVSc, FACVSc, PhD; Jean-Marie Denoix, DVM, PhD, Agregé; Joerg A. Auer, DrMedVet, Dr h c, MS, DACVS, DECVS