EXTRAARTICULAR TRANSPOSITION OF THE PATELLAR TENDON FOR ANTEROLATERALINSTABILITY OF THE KNEE

Several extraarticular surgical procedures have been proposed to elimi nate the anterolateral rotatory instability of an anterior cruciate-de ficient knee. We examined the outcome in 52 patients with an extraarti cular transposition of the lateral third of the patellar tendon to the lateral femoral condyle. The mean follow-up time was 9 years. The eva luation was based on the patients' subjective assessment, the Tegner a ctivity level score, range of motion, Lysholm functional score, assess ment of knee instability using manual testing as well as arthrometer m easurements, and weight-bearing radiographs, At follow-up, 37 patients stated that they had good-to-excellent knee function. The mean Tegner score dropped from a preinjury level of 7 to 5. 43 patients had a goo d-to-excellent Lysholm score. 20 patients had a positive Lachman sign of grade 2 or 3, and 23 patients had a side-to-side difference of more than 3 mm as measured by an arthrometer. 17 had a positive pivot shif t sign. 12 patients had meniscal resections performed after the primar y operation, and 27 had radiographic evidence of arthrosis. Although t he outcome of this technique is equivalent to or better than results r eported for other extraarticular procedures, the recurrence rate of sy mptomatic instability and the deterioration of subjective knee functio n are too high.