Question: Our orthopedic surgeon completed a reconstruction of a posterior tendon tear. What procedure and diagnosis codes are best for the surgery? Kansas Subscriber Answer: Choose 27658 (Repair, flexor tendon, leg; primary, without graft, each tendon) or 27659 (... secondary, with or without graft, each tendon) for the procedure, depending on whether you're coding a primary or secondary repair. Then select your diagnosis based on whether therupture was traumatic or nontraumatic: 727.68 (Rupture of tendon, nontraumatic; other tendons of foot and ankle) or 845.00 (Sprains and strains of ankle and foot; unspecified site).