Posterior approach to knee joint. A, Posterior curvilinear incision. Posterior cutaneous nerve of calf exposed and retracted. B, Sciatic nerve and its division defined. C, Medial head of gastrocnemius muscle exposed. D, Tendon of origin of medial head of gastrocnemius muscle divided, exposing capsule of knee joint. If further exposure is necessary, lateral head of gastrocnemius is defined, incised, and retracted in similar fashion. SEE TECHNIQUE 1.54.