Abstract
Purpose: Free patellar tendon plasty is classically used for the treatment of chronic anterior instability of the knee. Good functional results may however be compromised by invalidating anterior pain. The purpose of this randomised trial was to obtain a prospective comparison of outcome after hamstring plasty or patellar tendon plasty.
Material and methods: One hundred patients with an isolated tear of the anterior cruciate ligament were included in the study between May 1998 and 2001. Exclusion criteria were history of fracture, grade II laxity, and tear of the contralateral ACL. Patients were assigned to one of the treatment arms in random order in the operating room: Group A: arthroscopic free patellar tendon-bone graft; Group B: arthroscopic free four-strand hamstring graft. Two metal interference screws were used for fixation in all cases. The Aglietti method was used to calculate the position of the bore holes in all cases. The same rehabilitation protocol, in the same centre, was applied in all cases. The two groups were comparable for epidemiological, clinical, radiological, and instrumental laxity (KT1000®) data. IKDC criteria, activity level (sports), and instrumental measurement of laxity (KT1000® Medtronic) were used to assess outcome. Differences were considered significant for p < 0.05.
Results: At mean follow-up (24 months, range 6 – 38) groups A and B were not significantly different for delay to resumed sports activity at the initial level, motion, clinical examination of ligaments, IKDC global score, and radiological evolution. At six months, 30% of the patients in group A complained of anterior pain; 20% of the patients still complained of pain at one year. In group B, femoropatellar pain or pain at the harvesting site was reported by 8% of the patients at six months and 4% at one year (p = 0.0005). These differences were no longer present at two years. The instrumental differential laxity was 0.66±1.1 mm in group A and 1±1.5 mm in group B (p =0.20). Two repeated trauma-induced tears were observed in group B.
Conclusion: The preliminary results of this prospective randomised trial confirm the low morbidity of the harvesting site for hamstring grafts and the reliable stability of hamstring repair of isolated ACL laxity. A longer follow-up is however needed for long-term validation, particular concerning secondary distension of hamstring grafts as is frequently reported in the literature and which we have also observed in certain patients treated before this series.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
