Reduction of medial compartment loads with valgus bracing of the osteoarthritic knee

Abstract

Background: Patients with medial compartment osteoarthritis of the knee may be treated nonoperatively with adjustable valgus bracing.

Hypothesis: Valgus bracing reduces load on the medial compartment through the application of an external valgus moment about the knee, resulting in pain relief.

Study design: Prospective cohort study.

Methods: Eleven patients were tested using an instrumented brace and three-dimensional gait analysis. We measured the valgus moment applied by the adjustable valgus brace and determined the compressive load in the medial compartment. We also documented the effects of increased valgus alignment of the brace and increased strap tension on load sharing. Pain and activity levels were also recorded.

Results: Pain and activity level improved in all subjects with valgus bracing. During gait, valgus bracing reduced the net varus moment about the knee by an average of 13% (7.1 N.m) and the medial compartment load at the knee by an average of 11% (114 N) in the calibrated 4 degrees valgus brace setting. Increasing valgus alignment with the adjustable brace had a greater effect on the medial compartment load than did increasing strap tension.

Conclusion: Adjustable valgus bracing was effective in reducing medial compartment load and subsequent pain while also improving knee function in a group of patients with osteoarthritis.