Abstract
The supporting structures on the medial side of the knee consist of:
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- Layer I, the superficial fascia.
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- Layer II, the superficial Medial Collateral Ligament (sMCL) with parallel fibers running from the femoral epicondyle to the anteromedial tibial crest 5–7 cm below the joint line.
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- Layer III, the deep capsular layer.
The pes tendons are situated between Layer I and II–III. Beneath the sMCL Layer III thickens and forms the deep MCL (dMCL) from femur condyle to meniscus and from meniscus to tibia.
More dorsally Layer II and III fuse and form the Postero Medial Capsule (PMC) which is connected to the meniscus and tibia. The PMC is augmented by the semimembranosus tendon.
The sMCL is the primary restraint against valgus and transsection causes 2–5 degrees laxity in flexion or approximately 3–5 mm joint opening. Additional cutting of the PMC gives additional laxity of 7–8 degrees up to 10 degrees. An isolated sMCL lesion causes more laxity in flexion and a combination of sMCL with a PMC lesion causes also laxity in extension. The dMCL does provide some stability in 45 dg. of flexion but is not very strong.
The goal of MCL-PMC reconstruction should be functional anatomical repair of the pathology and retention of the meniscus. After treating the pathology the medial side of the knee should be stable in extension (by repair PMC) and in flexion (by repair sMCL).
The PMC – meniscus – semimembranosus complex should be refixated at the posteromedial tibia corner if it is loose.
Bony avulsions should be fixed with washer and screw or anchors. Ligamentous avulsions can be fixed at the anatomical insertion site with trans-osseous non-resorbable sutures or bone anchors or screws with toothed washers. A distalisation of a ligament insertion (sMCL) with its bony attachment is also an elegant solution in chronic cases. If the surgeon wants to tension the SMCL at the femoral side, the bony insertion with the ligament attached to it can be recessed at its original position. Allografts and double stranded hamstring autografts can be used when native tissue is lacking.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
