Posterior Approach to Knee


- Discussion:
    - S shaped skin incision is made, extending along the posterior border of biceps and its tendon on the upper lateral side of popliteal fossa, then transversely across the fossa and finally along lower medial side of fossa posterior to semitendinosus tendon;
    - skin flaps are retracted and the deep fascia is incised in midline;
    - small saphenous vein is ligated if necessary but sural nerve must be preserved;
    - sural nerve is followed upwards to lead to the tibal nerve which is defined, together w/ space between nerve & semimembranous so that underlying head of gastrocnemius can be displayed;
         - sural nerve, which lies superficial to deep fascia below the knee, is used as a guide to the tibial nerve;
         - follow sural nerve upwards to pierce the deep fascia and lead to tibial nerve which is its parent trunk;
         - in popliteal fossa the tibial nerve lies superficial to popliteal vein, w/ popliteal artery deep to the vein;
    - large vessels and nerves in popliteal fossa are obvious hazards;
    - popliteal vessels are displaced laterally; in order to do this middle geniculate and possibly superior medial genicular vessels are ligated; (see genicular system);
    - medial head of the Gastrocnemius is traced upwards, detached from its origen and retracted towards the midline, so exposing joint capsule which can then be opened;
         - nerve and vessls to medial head of gastrocnemius must not be damaged but as both this head of muscle & main neurovascular bundle are retracted laterally, the risk is minimized



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, August 31, 2012 1:54 pm