Posterior "back and forth" approach in arthroscopic surgery on the posterior knee compartments.

We report the feasibility, indications, and usefulness of an arthroscopic approach to the posterior knee compartments. We developed an arthroscopic approach to the posterior knee compartment involving use of a posteromedial portal and a posterolateral portal opposite each other. Each posterior portal is used in alternation for the arthroscope and instruments. The posterior portals are established using an original "back and forth" technique. The feasibility of the technique was evaluated on a cadaver. It allowed us to define safety rules to protect the vessels and nerves that course through the popliteal fossa. The approach provided a broader field of view compared with classical techniques. After removal of the septum dividing the posterior compartment, the synovial fold enclosing the posterior cruciate ligament and lining the upper and posterior parts of the posterior capsule was readily accessed, suggesting that this approach may be particularly valuable for total synovectomy. This was confirmed in 6 patients with villonodular synovitis, in whom the new approach was used in combination with arthroscopic anterior synovectomy. This technique allows removal of parts of the synovium that are difficult to access through conventional arthroscopic approaches. For total synovectomy, it can be used as an alternative to open posterior synovectomy, in combination with arthroscopic anterior synovectomy.