Factors affecting outcome of ACL reconstruction in over-50-year-olds

With increasing life expectancy and ever-improving quality of life in industrialized countries, functional demand and sports levels are increasing in older subjects, who are thus exposed to central pivot lesions almost as much as younger ones. While non-operative treatment provides acceptable results, it entails significant reduction in sports level. The aim of the present study was to analyze medium-term clinical, functional and radiological results of anterior cruciate ligament (ACL) reconstruction in over-50-year-olds, in order to identify factors for failure.

The study hypothesis was that surgical management provides good results if patient selection is rigorous.

A multicenter retrospective study included 398 patients undergoing ACL reconstruction between April 1, 2009 and December 6, 2016. Inclusion criteria comprised: age≥50 years, with proven ACL tear. Preoperatively, clinical work-up was supplemented by measurement of differential anterior laxity and radiologic assessment of cartilage status. Functional level was assessed on the objective IKDC score. Intraoperative data comprised type of graft and meniscal and cartilage status. The same parameters were assessed postoperatively. Functional results were assessed on objective IKDS, KOOS and ACL-RSI scores.

The mean follow-up was 42.2 months. The mean improvement in differential anterior laxity was 4.2mm. Pivot-shift showed improvement, with 97% absent or glide (p<0.001). Objective IKDC score showed significant improvement (p<0.0001). 23% of patients had poor clinical results: IKDC C or D. Preoperative explosive pivot-shift (p<0.0001), medial tibiofemoral osteoarthritis (p<0.0001) and medial meniscus lesion (p<0.002) emerged as risk factors for poor functional outcome.

ACL reconstruction in over-50-year-olds provided satisfactory clinical and functional results. Rigorous patient selection is mandatory, as radiologic signs of medial tibiofemoral osteoarthritis indicate a risk of poor outcome. Surgery may be proposed in patients with high functional and athletic demand, before medial meniscal lesions can set in. In case of explosive pivot shift, associated anterolateral reconstruction should be considered.