INFRA-ARTICULAR RECONSTRUCTION OF THE ANT ERIOR CRUCIATE LIGAMENT WITH AND WITHOUT EXTRAARTICULAR SUPPLEMENTATION BY QUADRICIPITAL TENDON PLASTY - 4 YEAR FOLLOW-UP RESULTS

Purpose of the study The purpose of this study was to compare the func tional results obtained when an external extra-articular plasty was ad ded to an anterior cruciate ligament (ACL) reconstruction using an aut ologous bone tendon-bone patellar tendon graft. Material and methods T he authors analized two consecutive series of 60 and 50 patients opera ted by the same surgeon for a chronic rupture of the anterior cruciate ligament, one by reconstruction of the cruciate ligament with a free graft of the patellar tendon supplemented by an external extra-articul ar plasty made with a quadriceps tendon graft and the second with an i solated free patellar tendon graft. Anterior laxity was measured befor e and after surgery, by dynamic X-rays and by the Medmetric KT-1000 ar thrometer. Functional results were evaluated four years after operatio n, with the French A.R.P.E.GE score based on sport activity level and intensity. Results Anterior laxity was not different before operation in both groups and there was no difference between males and females. Medmetric KT-1000 arthrometer showed the same negative differential la xity immediately after surgery in both groups and the same evolution d uring the first 4 years, without any significant difference on laxity on the middle aspect of the knee. Radiological results were different. After a 4 years follow-up, anterior laxity did not show significant d ifference on the medial compartment of the knee (5.3 +/- 2.3 mm and 5. 5 +/- 1.7 mm), but there was a significant minor laxity in the lateral compartment for the lateral extra-articular plasty group (11.0 +/- 2. 3 mm against 14.8 +/- 3.8 mm) (p = 0.002). Functional results and spor t activity were similar in both groups. Examination showed 4 positive pivot shift tests (2 << sliding >> and 2 positive) in the group with e xtra-articular plasty, even though 8 positive pivot shift tests in the isolated ACL group (5 <<sliding>> and 3 positive) were found. Discuss ion This study, as well as five others studies found in literature, wa s not randomized. In all these series, the surgical techniques, the re habilitation programs and the functional score evaluation were too dif ferent to allow any pertinent comparison. Extra-articular plasty helps to control the laxity of the lateral compartment of the knee which is incompletely controled by ACL reconstruction, particularly in chronic cases. This is proved by radiological measurements and pivot shift te sts. Jensen in 1983, about 205 patients with a 4 year follow-up and No yes, which used an allograft patellar tendon, found an advantage to do extra-articular plasty. But Strum (in 1989), as O'Brien (in 1991) and Roth (in 1987), did not found any advantage with extra-articular plas ty. Conclusion It is therefore obvious, after a four-year follow-up, t hat extra-articular supplementation presents an advantage for reconstr uction of the ACL. by a free graft of the patellar tendon in chronic c ases. Further randomized study will confirm that isolated ACL reconstr uction is possible in some well definited categories of anterior laxit y.