RESUMO
OBJECTIVE: To assess the changes in patient strength and function from 4- to 6-month assessments following ACLR, determine relationships between changes in strength to changes in subjective function, and identify factors that predict patients that fail to increase in strength. DESIGN: Prospective, Cohort Study. SETTING: Controlled Laboratory. PARTICIPANTS: Forty-seven patients(27 female, 24.3 ± 11.1 years) completed a battery of performance assessments at approximately 4- and 6-months following primary ACLR (4.03 ±0 .49 and 6.46 ±0 .68 months). MAIN OUTCOME MEASURES: Subjective scores and isokinetic knee flexor and extensor strength were compared across visits. Patients were categorized per their ability to increase in strength beyond a previously defined threshold(0.22 Nm/kg). Binary logistic regression models were used to determine predictors of patients that failed to meet strength changes. RESULTS: Patients demonstrated improvements in patient-reported outcomes and strength measures between visits(P's < 0.05). Higher age (B = -0.073, P = .039), lower pre-injury activity levels (B = 0.61, P = .022), and higher limb symmetry indexes (B = -0.044, P = .05) at 4-months were predictors of patients that did not achieve improvements in quadriceps strength between assessments. CONCLUSIONS: From 4- to 6-months post-ACLR, increases in subjective function, strength and symmetry were observed. High quadriceps symmetry at interim assessments without consideration of the magnitude of strength values could overestimate recovery of quadriceps function.
