Nineteen patients with the clinical diagnosis of dysfunction of the
posterior tibial tendon underwent surgical exploration. Four types of
lesions were identified: avulsion of the tendon at the insertion (Group I),
mid-substance rupture of the tendon (Group II), an in-continuity tear of
the tendon (Group III), and no tendon tear, tenosynovitis only (Group IV).
These conditions could not be separated preoperatively by clinical or
radiographic means. The patients in Group I were treated by reinsertion of
the tendon; in Group II, by flexor tendon transfer; and in Groups III and
IV, by synovectomy. At follow-up, most patients in Group I reported no
improvement, but the patients in Groups II, III, and IV showed both
subjective and objective improvement. The signs and symptoms of dysfunction
of the posterior tibial tendon are not specific for mid-substance ruptures
of the tendon but also can occur with avulsions or synovitis, or perhaps
from other, as yet undefined lesions.