HAMSTRING PLASTY OF THE ANTERIOR CRUCIATE LIGAMENT: EVALUATION OF THE FEMORAL FIXATION

Abstract

Purpose: This prospective comparative study examined the two-year results of two femoral fixation method for anterior cruciate ligament (ACL) repair using the four-part hamstring technique. A consecutive series of 60 patients with the same tear criteria involving the ACL alone were randomly assigned to the two treatment arms. Femoral fixation was achieved by mixed corticocancellous transfixation or by interference screw fixation.

Material and methods: The series included two cohorts of 30 patients each. We excluded patients with a history of ligament or bone surgery and those with associated lesions of the peripheral ligaments. Complementary lateral reinforcement was not performed in either group. The interference screw fixation group had 20 men and 10 women, mean age 29 years (14–48), 18 right side. The blind femoral tunnel was drilled arthroscopically. The transfixation group included 19 men and 11 women, mean age 26 years (16–40), 17 right side. The blind femoral tunnel was drilled via a transtibial approach using the Rosenberg aiming procedure. In both cohorts, tibial fixation of the transplant was achieved with a resorbable polylactic screw measuring at least the diameter of the tibial tunnel. Statistical analysis of results (Statview 4.5) was based on the clinical IKDC score, thigh volume, and level of sports activity. Telos at 15 and 20 kg was used to measure laxity.

Results: Mean delay to review was 24 months (22–26). The two cohorts were comparable preoperatively (laxity, sports level, meniscal or cartilage lesions). There was no statistical difference for joint amplitudes, joint instability, or level of sports activity at last follow-up. The telos differential laxity at 15 kg was statistically lower in the interference screw fixation group (mean 1.1 mm) than in the transfixation group (mean 1.4 mm) (p < 0.01). There were no complications in either group, particularly no cyclope syndrome. Radiographically, there was no statistical difference for the position of the tibial tunnel. The femoral tunnel was however different: the Aglietti index was 0.57 for transfixation and 0.62 for interference screw fixation (p < 0.01).

Discussion: This prospective study demonstrated the good mid-term anatomic results after 4-part hamstring plasty of the ACL for both types of femoral fixation (transfixation or interference screw fixation). The position of the femoral tunnel appeared to be better with interference screw fixation, with a statistical correlation with better anatomic results (telos). This suggests that the transtibial femoral aiming procedure does not necessarily produce a totally satisfactory isometric alignment.