[Arthroscopic reconstruction of the anterior cruciate ligament].

PURPOSE OF THE STUDY: We report a retrospective series of 83 patients (86 knees) who underwent reconstruction surgery for chronic anterior knee laxity. The purpose of this study was to analyze mid-term results and assess prognosis factors.

MATERIAL AND

METHODS

All patients underwent artrhoscopic reconstruction of the anterior cruciate ligament using a central one-third patellar tendon graft. Full follow-up data were available for 51 patients (52 knees) and partial data for 24 others (25 knees). Eight patients (9 knees) were lost to follow-up. The IKDC criteria were used to analyze outcome at a mean 6 years post-surgery.

RESULTS

Graft failure was observed in 5 knees and a graft tears after a new sprain was seen at 3 years. The patients were satisfied or very satisfied in 88.5% of the cases. The Trillat-Lachman test revealed a persistent dampened brake in 5 knees and a frank click in 4 (7.7%). Complete movement was recovered in all knees excepting 2 exhibiting persistent flexion. Residual laxity (active Lachman test) was 5 mm in 81.5% of the cases, between 6 and 10 mm in 17%, and greater than 10 mm in only 1 case (2.5%). IKDC scores were A=25%, B=50%, C=21% and D=4%. Forty-two patients (61%) returned to their sports activities and 9 of the 12 high-level athletes resumed competition at the same level as preoperatively. Arthroscopy enabled a well- or very well-positioned femoral tunnel in 88% of the cases, conditioning final IKDC outcome (p<0.02). There was a correlation between the meniscal status and residual laxity.

DISCUSSION: This study demonstrated a high proportion (21%) of patients with an incomplete repair (21% IKDC class C) with a residual laxity greater than 5 mm and a late hard brake. Simple patellar tendon graft provided insufficient repair of the anterior cruciate ligament. The subjective outcome was better than the objective outcome since 88.5% of the patients were satisfied or very satisfied (patients seen at last follow-up or contacted by telephone). Good objective outcome was correlated with good femoral position of the transplant and preservation of the meniscus. Failures were explained by poor position of the transplant, long-standing laxity, and renewal of sports activities too early.

CONCLUSION

Arthroscopic repair of the anterior cruciate ligament is a reliable procedure, but as failures are observed, indications should take into consideration the type of laxity and the status of the meniscus. For unique anterior laxity, the central one-third patellar tendon graft gives good results. For advanced anterior laxity, augmentation with an extra-articular lateral tenodesis would be necessary.