OrthoNet

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