Impact of knee recurvatum on machine-assessed muscle recovery from isokinetic after anterior cruciate ligament surgery

Summary Background Recurvatum is generally considered to be a risk factor for graft tendon failure and a probable risk factor for native anterior cruciate ligament failure. Purpose To evaluate the impact of recurvatum and the type of anterior cruciate ligament repair on the hamstring/quadriceps ratio 4 months after surgery. Materiels and methods One hundred and three patients having undergone anterior cruciate ligament surgery were included between July 1st, 2017, and July 1st, 2018. A clinical check-up and an isokinetic test were performed 4 months after surgery. The hamstring/quadriceps ratio was calculated and then assessed as a function of the type of surgery and the presence or absence of recurvatum. Results The mean hamstring/quadriceps ratio on the operated side did not differ significantly (P = 0.87) when comparing patients with recurvatum (1.2) and those without (also 1.2). The interaction between the type of surgery and recurvatum was statistically significant (P = 0.019). In patients with recurvatum, the mean hamstring/quadriceps ratio was 1.49 in the patellar tendon group and 1.04 in the hamstring ligament group. Conclusion Neither the presence of recurvatum nor the type of surgery alone was related to the hamstring/quadriceps ratio on the operated side. However, the interaction between surgery and recurvatum was statistically significant. Patellar tendon technique should be preferred to the hamstring group technique in patients with recurvatum.