Leg-Length-Evening Device Improves Balance in Patients Wearing a Controlled Ankle Motion Boot: A Multicenter Randomized Controlled Trial

Abstract

Category: Other Introduction/Purpose: Patients are often made weight-bearing as tolerated (WBAT) in a controlled ankle motion (CAM) boot for the management of various foot and ankle conditions. The CAM boot causes a leg-length discrepancy (LLD) between the booted (longer) and contralateral (shorter) lower extremities. This discrepancy can potentially cause balance problems, undue strain on joints, and discomfort in patients. We hypothesized that a leg-length evening orthotic placed on the plantar aspect of the contralateral shoe improves balance among patients who are WBAT in a CAM boot. Methods: Patients made WBAT in a CAM boot were randomized to either the leg-length-evening orthotic intervention group or to a control group in which patients wore a normal shoe of their choice. Patients were followed for two weeks and asked a series of questions pertaining to balance and pain experienced at their knees, hips, and back. Balance was the primary outcome and was scored from 0 (no difficulty with balance) to 10 (great difficulty with balance). Results: Out of 107 subjects enrolled and randomized, 95 (88.8%) completed the study, satisfying the a priori sample size requirement of 94 patients. There were no differences in baseline characteristics between groups (p>0.05 for each). Intervention patients reported less difficulty with balance than control patients (intention-to-treat analysis: 2.0+-1.5 versus 3.2+-1.8, p=0.001; as-treated analysis: 2.1+-1.7 versus 3.0+-1.7, p=0.009). Intervention and control patients did not differ with respect to pain experienced at their knees, hips, or back, or in a composite total pain score (p>0.05 for each). Conclusion: This multicenter randomized controlled trial found that adding a limb-length-evening orthotic to the plantar aspect of the contralateral shoe in a patient that is WBAT in a CAM boot improves balance. The trial was powered to identify a difference in the primary outcome measure of balance and may have been insufficiently powered to identify differences in knee, hip, back, or total pain.