Considerations for the indications for anterior cruciate ligament reconstruction. Results of conservative versus operative treatment

Medium-term results with a follow-up of at least 3 years were done in 160 patients (average follow up 51 months) after ACL reconstruction using IKDC evaluation form and Noyes score and in 110 patients (average follow Up 53 months) after non-operative management. Unlike objective good parameters the subjective assessment of knee function according to the Noyes score reveals significantly worse results in cases with ACL reconstruction compared to the knees without surgery. The best functional results we found in professional athletes after ACL reconstruction. Comparable positive results of knee function is only achieved in approx. 15% of the patients from the natural history group, who can maintain high risk pivoting activity level feeling no giving way. In our opinion compensatory proprioceptive mechanism account for the surpassing results in these two groups of patients. It will be postulated that it is not the absolute power of the hamstring but the latency period of recruition that influences the compensation of anterior knee instability. We have modified our rehabilitation methods in order to improve proprioception and dynamic stability of the ACL-deficient knee. Based on our results we primarily limitate the ACL reconstruction on a group of patients practicing high-risk-pivoting sports. Only when menisceal lesions appear or patients suffer from giving way episodes we support secondary surgery, The pivot shift sign is reflecting the dynamic aspect of knee instability. In our opinion it is the decisive parameter to assess knee instability unless there are useful technical procederes.