chapter 5: Arthroscopy of the patellofemoral joint


Plicae are naturally occurring synovial folds in the knee. They are present in various locations in the knee with medial, superior, and inferior being the most common (25‑28). Inferior plica (ligamentum mucosum) are the most common plica but have not been reported to cause symptoms. The superior plica is rarely a problem. The medial plica is the most frequent to become symptomatic. A medial plica has been reported to be present in approximately 25% of all knees; 87% of these lesions are bilateral (25). These may become painful with overuse or blunt trauma (Fig. 5.19). The medial plica runs from the synovium just medial to the patella to the synovium of the anterior fat pad. A patient with a symptomatic medial plica will often complain of pain, grating, or even "catching" at the edge of the medial femoral condyle. This may rarely be accompanied by an effusion. A good physical examination will usually differentiate between the location of a symptomatic medial plica and a medial meniscus tear (most commonly confused with a medial plica), as the meniscus pain will be located along the tibiofemoral line. Not all medial plicae noted at arthroscopy are symptomatic, making the meticulous preoperative physical examination imperative. The confidence level of relieving symptoms by removing the plica at arthroscopy rises with positive preoperative findings. Palpate for a snapping, painful band over the medial femoral condyle near the edge of the trochlea as you flex and extend the patient's knee between 30 and 90 degrees. Other common causes of pain in this area can be an osteophyte or synovitis along the medial aspect of the trochlea. These can often be palpated, and an osteophyte may be noted on the Merchant radiograph or other knee radiographs. Removing these symptomatic synovia or osteophytes will often give pain relief.

Conservative treatment of plicae consists of anti‑inflammatory agents and rest. If this fails, removal of the plica is warranted. At arthroscopy, medial plicae are seen best from the superomedial portal (your regularly unobstructed view down the medial gutter or medial half of the trochlea may be blocked by the plica), or the inferolateral portal. The superolateral portal has also been reported to be beneficial at giving a good view of the medial plica (29). The symptomatic plica will often look inflamed, thickened, and sometimes fibrotic. If you are looking from the superomedial view, your cautery, arthroscopic knife, or basket forceps may be placed through the inferolateral or inferomedial portal for removal (Figs. 5.19 and 5.20). Once the plica is cut, the edges often retract due to the tension the plica had been under. If you are viewing through an inferolateral portal, you can work through a superolateral or inferomedial portal. A shaver may be introduced to remove the remaining edges. Resection rather than division of the plica is preferred.

Results of plica excision vary in the literature. Broom and Fulkerson reported 77% good/excellent results, with average follow‑up of 17 months (3). Nottage et al reported only a 9% failure rate (30); Jackson et al, 24% (31); and Dorchak et al, 25% (6). Many authors agree that the success rate for resection of a plica drops with concomitant pathology (3). Broom noted an association between pathologic plicae and abnormal patellofemoral mechanics.  The main complication from plica resection is a postoperative hemarthrosis.




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