BACKGROUND: The decision to return to sport following anterior cruciate ligament (ACL) reconstruction should not only be based on time since surgery. This study aimed to assess, using isokinetic and neuromuscular (hops) testing in a large group, postoperative objective functional recovery of the knee. The secondary objective was to determine the relationship between psychological, functional scores, and these postoperative tests.
METHODS: This prospective study included athletes who underwent surgery between 2013 and 2016 for an isolated full-thickness ACL tear. They received a complete evaluation of functional performance of the knee by isokinetic tests performed on a dynamometer to measure quadriceps and hamstring strength, and neuromuscular assessment based on single-leg hop tests. The main judgment criterion was satisfactory functional recovery (yes/no) defined as a difference of ≤10% both in the quadriceps 60°/s and the single hop at a minimum of four months of follow-up.
RESULTS: A total of 234 athletes were analyzed. The mean age was 28.4 ± 8.6 years. At 6.5 ± 1.7 months mean follow-up, 44 (18.5%) patients had satisfactory functional recovery of the knee. The correlations between isokinetic/hop tests and the different scores were variable. During follow-up, two patients presented with a graft tear and two with a contralateral ACL tear, all in the group with unsatisfactory functional recovery.
CONCLUSION: At a mean of six months after ACL reconstruction, objective functional recovery of the knee was generally unsatisfactory and this seemed to be a risk factor for recurrent tears. LEVEL OF EVIDENCE: IV; case series.
ACL-RSI scale (Anterior Cruciate Ligament-Return to Sport after Injury); Isokinetic tests; Primary ACL reconstruction; Return to sport; Single-limb hop tests