[Reconstruction of the anterior cruciate ligament by bone-patellar tendon transplant. Evaluation of 79 cases. Prognostic factors]

Abstract

Purpose of the study: The purpose of this study was to evaluate the results of the anterior cruciate ligament (A.C.L.) reconstruction according to two scoring systems (Arpege and IKDC), to analyse the influence of different factors on the results, to study the effect of a lateral extra-articular tenodesis, the morbidity of patellar tendon graft harvesting, and the advantage of arthroscopically assisted reconstruction.

Material: Seventy nine patients, 17 to 39 years old (average 27 years), underwent an anterior cruciate ligament reconstruction for chronic instability, using a free bone-patellar tendon-bone graft. In 43 cases, a lateral extra-articular plasty was added (Lemaire's procedure). The reconstruction was arthroscopically assisted in 17 cases. Interval between initial injury and surgery was 24 months (2 months to 9 years and 7 months). The average follow-up was 2.5 years (range 1 to 18).

Method: All patients were reviewed for evaluation with two scoring systems (Arpege and IKDC). Roentgenograms of both knees, including antero-posterior weight-bearing and lateral view, patellar view, dynamic radiographs, allowed evaluation of post-operative arthrosis and residual anterior laxity in extension. Fischer's test and chi square test were used for statistical evaluation.

Results: Using the Arpege CLAS system, functional results were excellent or good in 75.9 per cent of cases (excellent in 44.3 per cent, good in 31.6 per cent), fair in 15.2 per cent, poor in 8.9 per cent; according to the IKDC system, 65.8 per cent were excellent or good. 84.8 per cent of the patients were satisfied in Arpege system and 91.2 per cent in IKDC system. The pivot-shift test was negative in 86 per cent, equivocal in 7.6 per cent and positive in 6.4 per cent. The radiological Lachman's test (difference between control and affected knee) was 0-2 mm in 53.2 per cent, 3-5 mm in 39.2 per cent, 6-10 mm in 7.6 per cent, never greater than 10 mm. Antero-posterior weight-bearing radiographs were normal in 83.5 per cent, showed joint remodeling in 10.1 per cent pre-arthrosis in 6.3 per cent but no arthrosis. Functional results were not correlated with age at time of surgery, interval between initial injury and surgery, nor clinical Lachman's test. Competitive sportsmen had a better result (p = 0.001). Residual laxity in extension was correlated with lesions of medial meniscus (p = 0.035). Degenerative changes in femoro-tibial joint were correlated with residual laxity in extension (p = 0.019). There was no significative difference between A.C.L. reconstruction isolated or associated with lateral extra-articular tenodesis. Time to return to work was shorter for patients with arthroscopically assisted procedure (p = 0.067).

Discussion and conclusion: Functional results after A.C.L. reconstruction using a free bone-patellar tendon-bone graft are satisfactory and confirm the reliability of this procedure. Arpege CLAS and IKDC systems give comparable functional results, but IKDC evaluate anatomical results, residual laxity and degenerative changes of the joint, that constitute essential long-term pronostic factors. Morbidity of patellar tendon harvesting appears to be of short duration and largely reversible. Added lateral extra-articular tenodesis doesn't improve the results. Arthroscopically assisted procedure seems to allow a faster rehabilitation.