Bilateral proprioceptive defects in patients with a unilateral anterior cruciate ligament reconstruction: A comparison between patients and healthy individuals

Proprioception of the knee was measured in 20 patients with reconstructed a nterior cruciate ligaments and in 19 age-matched controls. The mean time fr om surgery was 2 years. Three tests of proprioception were used: (a) thresh old to detection of passive motion from 20 and 40 degrees toward flexion an d extension, (b) active reproduction of a 30 degrees passive angle change, and (c) visual reproduction of a 30 degrees passive angle change. The aim w as a complete, bilateral, proprioceptive evaluation of patients who had und ergone reconstruction of the anterior cruciate ligament. As compared with t hose in the control group, the knees with reconstructed anterior cruciate l igaments had a higher threshold to detection of passive motion in the exten sion trials from 20 and 40 degrees (p = 0.0003 and 0.04, respectively) and in the flexion trials from 20 and 40 degrees (p = 0.004 and 0.0008, respect ively). When the uninjured knees of the patients were compared with those i n the control group, higher values for threshold to detection of passive mo tion were found in the flexion trials from 20 degrees (p = 0.002) and 40 de grees (p = 0.02). Thus, decreased proprioceptive ability was present in som e measurements of these patients after reconstructive surgery, not only in injured knees but also in uninjured knees, as compared with the reference g roup. The functional relevance of these findings was not investigated in th is study, but the results suggest that bilateral proprioceptive considerati ons should be made when evaluating prognostic factors, treatment, and risk of contralateral knee injury in patients with reconstructed anterior crucia te ligaments.