Dynamic postural stability and asymmetry in thigh circumference and single-leg hop test following anterior cruciate ligament reconstruction

Abstract

Purpose: To evaluate changes in limb symmetry index (LSI) in thigh circumference and single-leg hop for distance (SLHD) after anterior cruciate ligament reconstruction (ACLR) out to 18 months postoperatively and their association to changes in dynamic postural stability after ACLR out to 24 months. Methods: Patients were prospectively enroled after ACLR and followed up at 3-month intervals. Thigh circumference was measured preoperatively out to 18 months postoperatively, dynamic postural stability out to 24 months, and SLHD from 6 to 18 months following ACLR. LSI was calculated from the thigh circumference and SLHD measurements. Dynamic postural stability (DPS) was measured on a multidirectional platform that tracked the patient's centre of mass, creating a dynamic motion analysis (DMA) score that reflected ability to maintain their centre of mass. Results: A total of 47 patients with mean age of 19.1 ± 5.8 years completed the study. LSI in thigh circumference worsened initially and improved at longer follow-up. LSI in SLHD improved significantly at 9- and 12-months consecutively. Overall mean DMA scores improved significantly at 3- and 6-month postoperatively. No significant correlation between LSI and DMA scores was appreciated at any time point. Conclusions: LSI in thigh circumference decreases initially after ACLR and then improves, while LSI in SLHD and dynamic postural stability improved after ACLR. DPS improved primarily in translational planes of motion. No significant association between LSI in thigh circumference/SLHD and DPS was found at any follow-up point. Level of Evidence: Level IV, case series.