10 to 16 years follow-up results of 138 anterior cruciate ligament reconstruction for chronic instability of the knee using the central third of the patellar tendon augmented by extra-articular plasty

Purpose of the study The aim of this prospective study was to evaluate the objective postoperati ve laxity and functional results with a minimum follow-up of 10 years (mean 11,7 +/-: 2 years) in chronic anterior knee instability treated by ACL rec onstruction associated to a lateral extra-articular plasty. Material and methods 138 patients of a mean age of 27,8 +/- 8,5 years had been operated. Delay b etween injury and operation was 4 +/- 4,8 years. The surgical "Mac Injones" procedure used a tree autologous patellar tendon graft with a bone-to-bone fixation, supplemented by a lateral extra-articular plasty using a strip o f quadriceps tendon as a direct prolongation of the graft of the patellar t endon and patella itself. A rehabilitation program aimed to an early recove ry of a complete range of motion. Anterior laxity had been measured before and after operation using two instrumented methods, KT-1000 and stressradio graphy (at 20 degrees of flexion with a 9 kg load applied at the distal par t of the thigh) with measurements of the displacement in medial and lateral compartments. Tunnel positioning was appreciated radiologically. Function was evaluated using the international Knee Documentation Commitee score (I. K.D.C.). Results Elongation of the reconstructed ligament occured mainly during the first 6 month, but was independant from early full range of motion recovery. Laxity was stabilized after one year. The final laxity gain of the medial compart ment was 62 per cent and for the lateral compartment 77 per cent. The pivot shift test was negative in 66 per cent, grade 2 in 4 per cent, grade 1 in 30 per cent. Functional results were excellent and good (A and B) in 60,4 p er cent and 76,7 per cent returned to sports activity. 12 reconstructed lig aments reruptured. Arthritis was the cause of poor results in other cases ( 13,8 per cent). Discussion Lateral extra-articular plasty is unable to better control translation of t he medial compartment than isolated anterior cruciate ligament reconstructi on, but laxity of the lateral compartment was minimized and the Pivot shift test also, Incorrect position of the anterior cruciate ligament was correl ated with poor results. Conclusion This documented study on rarity of the two compartments confirms the intere st of each type of reconstruction, in particular extra-articular plasty whe n made with quadriceps tendon and so doing, preserving the iliotibial-band for the control of varus stability.