Knee Braces for Lateral Compartment Osteoarthritis
No definitive recommendation can be made for or against the use of a brace with a varus-directing force for patients with lateral unicompartmental osteoarthritis of the knee due to insufficient evidence. 1
Current Evidence on Lateral Compartment OA Bracing
The American Academy of Orthopaedic Surgeons (AAOS) clinical practice guidelines specifically address this question but found insufficient evidence to make a recommendation. The guideline states:
- Level of Evidence: V (expert opinion only)
- Grade of Recommendation: Inconclusive
- No studies were identified by systematic review processes specific to patients with lateral tibiofemoral OA of the knee 1
While there is research on bracing for medial compartment OA, the evidence for lateral compartment OA is notably lacking. This creates a significant gap in clinical guidance.
Understanding the Biomechanical Principles
Lateral compartment OA typically involves:
- Valgus knee alignment (knock-kneed appearance)
- Increased loading on the lateral compartment
- Theoretical benefit from a varus-directing force brace that would shift load away from the lateral compartment
In theory, a varus-directing brace would work opposite to the more common valgus-directing braces used for medial compartment OA. The brace would aim to alter a valgus malaligned knee by moving the alignment in a varus direction to unload the lateral compartment.
Evidence from Related Research
While specific evidence for lateral compartment OA bracing is lacking, we can draw some insights from research on medial compartment OA bracing:
- Unloader braces for medial compartment OA have shown effectiveness in reducing pain and improving function 2, 3
- A 2019 study showed that both conventional knee unloader braces and foot ankle orthoses were effective for medial compartment OA 4
- Biomechanical studies have demonstrated that valgus bracing can reduce medial compartment loads by approximately 11% during gait 5
Clinical Approach to Lateral Compartment OA
Given the lack of specific evidence for lateral compartment OA bracing, a clinical approach might include:
Consider trial of varus-directing unloader brace:
- Despite lack of specific evidence, biomechanical principles suggest potential benefit
- Monitor for symptomatic improvement in pain and function
- Assess patient tolerance and compliance
Alternative non-surgical approaches:
- Weight management for overweight patients
- Exercise and quadriceps strengthening (Grade A recommendation) 1
- Physical therapy
- Analgesics as needed
Brace selection considerations:
- Pull-mechanism unloaders may be more effective than push-mechanism designs 6
- Patient comfort and ease of use significantly impact compliance
- Consider both conventional knee braces and newer foot-ankle orthosis designs
Common Pitfalls and Caveats
- Patient compliance: Brace discomfort, skin irritation, and poor fit are common reasons for non-adherence
- Biomechanical variability: Individual response to bracing varies based on anatomy and alignment
- Unrealistic expectations: Bracing may provide symptomatic relief but does not alter disease progression
- Contraindications: Significant fixed deformities or instability may limit brace effectiveness
- Cost considerations: Insurance coverage varies, and out-of-pocket expenses may be substantial
Conclusion for Clinical Practice
For patients with lateral compartment osteoarthritis, the evidence does not support a definitive recommendation for or against varus-directing knee braces. A trial of bracing may be reasonable as part of a comprehensive management approach that includes exercise, weight management, and appropriate analgesics. The decision should be made with an understanding of the limited evidence base and close monitoring of symptomatic response.