Dislocations of the Proximal Tib/Fib Joint
Reference: Ogden, JBJS 56A, 145-154
– Acute dislocations are treated with closed reduction usually, and are usually stable. If unstable, open reduction and ligamentous repair +/- K-wiring is recommended. Arthrodesis is not recommended because it screws up ankle motion. If peroneal nerve symptoms arise, consider resection of the fibular head.
Points of Interest
– Classified into subluxation and 3 types of dislocation – superior, anterolateral, posteromedial.
– Often associated with severe trauma, and often missed
– The joint is supported anteriorly by thickened capsule, which is probably extension from biceps tendon.
– Posteriorly, there is a thick capsule reinforced by popliteus
– The fibular collateral ligament provides the most proximal support of the joint.
Acute dislocations – require muscle relaxation, then flexion of the knee to relax the ligament, followed by a firm push in the direction required. Once reduced, they are usually stable. They generally speaking do not require immobilization, and non-weightbearing is recommended for 2 weeks.
In the rare case where closed reduction is unsuccessful, it is debatable what to do. The authors in Rockwood and Green suggest that leaving them alone with a recurrently subluxating joint is okay, and if they run into problems down the road you can offer further treatment – fixation, arthrodesis, resection.
If you need to treat someone with recurrent instability and PAIN, open reduction and internal fixation with K-wires that are removed at 6 weeks is suggested, or simple resection if peroneal nerve symptoms occur. Arthrodesis is not advocated because of long-term discomfort in the ankle.