Knee – Medial Approach

Knee – medial approach

* position – supine with affected knee flexed to 60 deg. & hip flexed & ER

* incision
– long, curved incision starting 2 cm prox. to add. tubercle
– curve ant. & inf. to point 6 cm below joint line on anteromed. aspect of tibia
– runs parallel to med. border of patella about 3 cm med. to it

* no internervous plane

* dissection
– raise skin flaps to expose fascia
– infrapatellar branch of saphenous n. crosses operative field transversely (usu cut)
– saphenous n. emerges from btw gracilis & sartorius
– long saphenous v. runs in posteromed. aspect of dissection

> ant. to superficial MCL
– incise fascia along ant. border of sartorius in line with muscle fibers from attachment to tibia to 5 cm above joint line
– flex knee to allow sartorius to retract post.
– ST & gracilis exposed behind & beneath sartorius
– retract all 3 muscles post.
– insertion of sup. MCL lies deep & distal to ant. edge of sartorius
– gentle traction to MCL will expose injury
– for intraart. exposure, incise joint capsule ant. to MCL

> post. to superficial MCL
– incise fascia along ant. border of sartorius
– retract 3 muscles of pes anserinus post.
– separate med. head of gastroc. from semimembranosus
– separate med. head of gastroc. from post. capsule
– exposes posteromed. corner
– incise capsule post. to MCL for intraart. exposure

* dangers
– infrapatellar branch of saphenous n. – usu cut
– saphenous n. – emerges btw sartorius & gracilis with long saphenous v.
– long saphenous v.
– med. inf. genicular art. – curves around upper end of tibia & may be damaged when med. head of gastroc. lifted off post. capsule
– popliteal art. – lies on post. capsule in midline & adj. to med. head of gastroc.

* special problems
– use drain — hematoma under skin flaps can cause skin necrosis