Background: While the use of functional knee braces for return to sports or high level physical activity after ACL reconstruction (ACLR) is controversial, brace use is still prevalent.(1,2,3,4,5) All active patients in the practice are braced after ACLR and must pass a battery of sports tests before they return to play in their brace. Criteria include a 90% score on 4 one-legged hop tests(9) burst superimposition strength test,(10) Knee Outcome Survey Activities of Daily Living Scale,(8) and a global rating of knee function.
Purpose: The purpose of this study was to describe the use of criterion-based guidelines to determine if athletes who had undergone an ACLR function better with or without their functional brace, one year after surgery.
Study design: Cross-Sectional Study.
Methods: Sixty-four patients post ACLR performed 4 one-legged hop tests,(9) burst superimposition strength test,(10) and completed the Knee Outcome Survey Activities of Daily Living Scale,(8) and a global rating of knee function one year after surgery with and without their brace.
Results: Participants included 35 men and 29 women with a mean age of 25 years. The Mean Knee Outcome Survey Activities of Daily Living score was 98%, and the global rating was 97%. Of the subjects, one patient failed hop testing by at least one criterion with and without the brace. Three additional patients failed the test while braced but passed un-braced, and one patient passed with the brace, but failed without the brace. Subjects performed significantly better un-braced than braced in all hop tests: single leg hop braced = 101%; un-braced = 107% (p<0.001); cross-over hop braced = 100%; un-braced = 105% (p<0.001); triple hop braced = 99%; un-braced = 101% (p=0.003); timed hop braced = 98%; un-braced = 103% (p = 0.004).
Conclusions: Sixty-two of 64 patients continued to score above return to play criteria one year after ACLR. All but two subjects in the cohort performed better un-braced than braced. Based on the criterion set for this testing session, 62/64 individuals performed well enough to discontinue use of their brace.
Level of evidence: 2b.
Keywords: ACL; functional brace; hop tests; knee.