Measurements for a safe return to sports after ACL reconstruction.

For athletes rehabilitation after anterior cruciate ligament reconstruction (ACLR) could be judged successful if they return to their previous level of sports. Recent research, however, shows that one third of athletes does not return to this sport level within two years. After three or more years this number even increases to 50%. Half of these athletes report their ACL injury as the primary reason for a lower activity level. Moreover, athletes that do return to their previous sport level have a considerable risk of tearing the graft or the contralateral ACL within the first two years; 3-22% of athletes rerupture the reconstructed ligament and 3-24% rupture the contralateral ACL. The risk of a contralateral ACL injury is higher when returning to a high level of pivoting sports. Three recent systematic reviews show that most clinicians do not use objective criteria for determining the moment of return to sports. Furthermore, there are no measurements for quality of movement performed, despite previous studies showed that, besides quantity, also quality of movement can be a causal factor for ACL (re)ruptures. The presence of dynamic knee valgus when landing from a jump and deficits in neuromuscular control of the trunk can predict ACL injury in healthy athletes. Also, the occurrence of dynamic knee valgus and a smaller knee flexion angle during landing are predictive for ACL rerupture. It can be concluded that both components of functional performance are important in rehabilitation after ACLR and prevention of (re)injuries.
Nevertheless, there has never been conducted a prospective cohort study with ACLR athletes, to investigate whether an extensive test battery for measuring quantity and quality of movement is able to predict safe return to sports.

The aim of this study is to correlate the score on a functional performance test battery to the occurence of ACL reruptures and contralateral ruptures. We hypothesize that athletes with a limb symmetry index of <100% on strength or hoptests or a bad quality of movement have more risk for graft rerupture or contralateral rupture.

Measurements are conducted at the following timepoints:

T0 – preoperative

T1 – at the end of the first postoperative phase

T2 – at the end of the second postoperative phase

T3 – at the end of the third postoperative phase

T4 – 1 year postoperative

T5 – 1 year and 3 months postoperative

T6 – 1 year and 6 months postoperative

T7 – 1 year and 9 months postoperative

T8 – 2 years postoperative

The rehabilitation after ACLR will follow the KNGF Evidence Statement (that will be published in the fall of 2013). Measurement of functional performance are according to the Evidence Statement. The measurements include both quantity and quality of functional performance: strength measurements, hoptest battery, video-analysis for quality of movement during drop jump. Before surgery and after finishing rehabilitation, only an online questionnaire is send, with questions about return to sports and injuries.