Orthopedic Coding Alert

Question: Please explain what posterior tibial tendon dysfunction is. What ICD-9 code best represents this condition?

Lorraine Anderson
Lincoln, Neb.

Answer: There are four stages of posterior tibial tendon dysfunction. Patients with stage I disease usually complain of pain along the course of the tendon, and there is evidence of local tendon inflammation. Patients with stage II disease show a mobile deformity of the hindfoot. A fixed hindfoot deformity and usually a fixed forefoot supination deformity characterize stage III. In the final stage, stage IV, there is evidence of ankle joint involvement secondary to the long-standing hindfoot deformity.

ICD9 codes for each stage are as follows:

Stage I 726.72 (tibialis tendinitis)
Stage II 736.70 (unspecified deformity of ankle and foot, acquired), and/or 736.76 (other calcaneus deformity) and/or 736.79 (other acquired deformity of ankle and foot)
Stage III is the same as stage II, plus 736.72 (equinus deformity of foot, acquired) and/or 736.73 (cavus deformity of foot)
Stage IV is the same as stage III, perhaps with the addition of 715.X7 (osteoarthritis of ankle), if this condition is present.