Sensorimotor changes after anterior cruciate ligament reconstruction

The restoration of joint stability is unlikely to be dependent on passive properties of the joint alone, yet the effect of anterior cruciate ligament reconstructive surgery on the sensorimotor system largely remains unexplored. This study evaluated whether surgical reconstruction of the ligament had any effect on one indicator of sensorimotor function, hamstring contraction latency, which previously has been shown to be related to function. Twenty-five patients with unilateral chronic anterior cruciate ligament deficiency had measures of hamstring contraction latency obtained before and after (3 and 6 months) reconstruction. After surgery, the contraction latency difference was found to improve significantly (decrease) in patients who had a preexisting deficit. The mechanism for alteration in response time remains unclear, but an observed relationship between contraction latency and tibial translation supports a mechanical basis for the findings. It was concluded the sensorimotor changes associated with surgical reconstruction of the cruciate ligament may help to restore joint stability. The study highlights the need to appreciate sensorimotor consequences of cruciate ligament surgery.