Kendal Marriott

Biomechanical effects of valgus knee bracing: a systematic review and meta-analysis

To review and synthesize the biomechanical effects of valgus knee bracing for patients with medial knee osteoarthritis (OA). Electronic databases were searched from their inception to May 2014. Two reviewers independently determined study eligibility, rated study quality and extracted data. Where possible, data were combined into meta-analyses and pooled estimates with 95% confidence intervals (CI) for standardized mean differences (SMD) were calculated. Thirty studies were included with 478 subjects tested while using a valgus knee brace. Various biomechanical methods suggested valgus braces can decrease direct measures of medial knee compressive force, indirect measures representing the mediolateral distribution of load across the knee, quadriceps/hamstring and quadriceps/gastrocnemius co-contraction ratios, and increase medial joint space during gait. Meta-analysis from 17 studies suggested a statistically significant decrease in the external knee adduction moment (KAM) during walking, with a moderate-to-high effect size (SMD = 0.61; 95% CI: 0.39, 0.83; P < 0.001). Meta-regression identified a near-significant association for the KAM effect size and duration of brace use only (β, -0.01; 95% CI: -0.03, 0.0001; P = 0.06); with longer durations of brace use associated with smaller treatment effects. Minor complications were commonly reported during brace use and included slipping, discomfort and poor fit, blisters and skin irritation. Systematic review and meta-analysis suggests valgus knee braces can alter knee joint loads through a combination of mechanisms, with moderate-to-high effect sizes in biomechanical outcomes.

Valgus Bracing for Knee Osteoarthritis: A Meta‐Analysis of Randomized Trials

To evaluate the effects of valgus knee bracing on pain and function, and compliance and complications, in patients with medial knee osteoarthritis (OA).

Five-year changes in gait biomechanics after concomitant high tibial osteotomy and ACL reconstruction in patients with medial knee osteoarthritis.

Background: Concomitant high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction is a combined surgical procedure intended to improve kinematics and kinetics in the unstable ACL-deficient knee with varus malalignment and medial compartment knee osteoarthritis (OA). Purpose: To investigate 5-year changes in gait biomechanics as well as radiographic and patient-reported outcomes bilaterally after unilateral, concomitant medial opening wedge HTO and ACL reconstruction. Study Design: Controlled laboratory study. Methods: A total of 33 patients (mean ± SD age, 40 ± 9 years) with varus malalignment (mean mechanical axis angle, −5.9° ± 2.9°), medial compartment knee OA, and ACL deficiency completed 3-dimensional gait analysis preoperatively and 2 and 5 years postoperatively. Primary outcomes were the peak external knee adduction (first peak) and flexion moments. Secondary outcomes were the peak external knee extension and transverse plane moments, peak knee angles in all 3 planes, radiographic static knee alignment measures (mechanical axis angle and posterior tibial slope), and the Knee injury and Osteoarthritis Outcome Score (KOOS). Results: There was a substantial decrease in the knee adduction moment in the surgical limb (%BW × H, −1.49; 95% CI, −1.75 to −1.22) and a slight increase in the nonsurgical limb (%BW × H, 0.16; 95% CI, 0.03 to 0.30) from preoperatively to 5 years postoperatively. There was also a decrease in the knee flexion moment for both the surgical (%BW × H, −0.67; 95% CI, −1.19 to −0.15) and nonsurgical limbs (%BW × H, –1.06; 95% CI, –1.49 to −0.64). Secondary outcomes suggested that substantial improvements were maintained at 5 years, although smaller declines were observed in several measures and in both limbs from 2 to 5 years. Conclusion: Changes in the peak external moments about the knee in all 3 planes during walking were observed 5 years after concomitant medial opening wedge HTO and ACL reconstruction. These findings are consistent with an intended, sustained shift in the mediolateral distribution of knee loads. Clinical Relevance: These findings suggest that concomitant HTO and ACL reconstruction results in substantial changes in gait biomechanics. Future clinical research comparing treatment strategies is both warranted and required for this relatively uncommon but seemingly biomechanically efficacious procedure.

GAIT BIOMECHANICS AFTER COMBINED HTO-ACL RECONSTRUCTION VERSUS HTO ALONE: A MATCHED COHORT STUDY: HTO-ACLR Versus HTO

The purpose of the present study was to compare bilateral external knee moments during gait in patients with concomitant medial compartment knee OA, varus alignment and chronic anterior cruciate ligament (ACL) deficiency who underwent either medial opening‐wedge high tibial osteotomy alone (HTO) or simultaneous HTO and ACL reconstruction (HTO‐ACLR). Fifty‐two patients (26 matched pairs) completed 3D gait analysis preoperatively and at a minimum 5 years postoperatively. Patients were matched for preoperative age, sex, body mass index and magnitude of correction. Primary outcomes selected a priori were the peak knee adduction moment (KAM) and knee flexion (KFM) moment during stance. Moments were compared using mixed model repeated measures analysis of variance (ANOVA). For the peak KAM, there was a significant time by limb interaction. For both groups, there were similar reductions in the peak KAM 5 years postoperatively in the surgical limb only [−1.34 %BW × Ht (−1.71, −0.96) and −1.72 %BW × Ht (−1.99, −1.44) for HTO and HTO‐ACLR, respectively]. For the peak KFM, there was a significant time by group by limb interaction. There was a decrease in the peak KFM 5 years postoperatively in the HTO group [−0.88 %BW × Ht (−1.45, −0.31)] but not in the HTO‐ACLR group [0.03 %BW × Ht (−0.43, 0.48)]. These results suggest that individuals with medial knee OA, varus alignment and chronic ACL deficiency who undergo simultaneous medial opening‐wedge HTO and ACL reconstruction may not experience the same long‐term (5 year) changes in sagittal plane knee biomechanics observed in patients undergoing HTO alone.

Association Between Knee Load and Pain: Within-Patient, Between-Knees, Case-Control Study in Patients with Knee Osteoarthritis

The association between knee loading and pain in patients with knee osteoarthritis is reported to be low and of questionable importance, but may be confounded by several factors that differ between patients. We aimed to elucidate the association between dynamic knee load and pain by minimizing confounding using a study design that was within the same patient, with knees discordant for pain.