COMPARATIVE STUDY OF ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH AND WITHOUT COMPUTER ASSISATNCE: A PROSPECTIVE ANALYSIS OF 73 KNEES

Abstract

Purpose of the study: The correct position of the femoral and tibial tunnes for anterior cruciate ligament (ACL) reconstruction is a determining factor for favorable outcome. We used a novel computer-assisted system which enables intraoperative localization of the tunnel centers on the lateral view of the knee before drilling. This technique uses fluoroscopy combined with a passive system for computer-assisted image acquisition and processing to provide the surgeon with the desired positions. We report the anatomic and clinical results observed in a prospective series comparing this technique with the classical technique of independent blind tunnels.

Material and methods: Thirty-seven patients underwent computer-assisted surgery and 36 classical surgery without computer assistance performed by a senior surgeon. Mean patient age was 27 years in both groups. The patients were reviewed at mean 2.2 years (range 1–4.5 years). Data recorded included the KT-1000 laxity, radiographic drawer and the IKDC score (1999).

Results: Mean time from ACL tear to reconstruction was 30 months in both groups. Computer assistance increased operative time 9.3 minutes (range 4–13). The IKDC score was 67.9% A, 29.7% B, and 2.7% C in computer-assistance surgery patients and 60% A, 37.1% B and 2.9% B for classical surgery patients. The mean IKDC function score was 89.7/100 for the computer-assisted patients and 89.5/100 for the others. Mean manual maximal laxity (KT-1000) was 7 mm before surgery and less than 2 mm at last follow-up. Differential laxity was less than 2 mm in all patients who underwent computer-assisted surgery and in 97.7% of the others. The mean differential laxity for the medial compartment as measured on the postoperative stress films was 2.4 mm (range 0–12 mm) for computer-assisted surgery patients and 3 mm (range 0–10 mm) for the others. In the computer-assised surgery patients, the femoral tunnels were centered on a smaller area. There was not significant difference in the IKDC score, the KT-1000 findings and the stress x-rays between the two techniques.

Conclusion: The results of these two techniques in this report are similar to data reported in the literature. Computer-assistance enables more accurate and reproducible tunnel positioning with no significant clinical impact.