S G Bodkin1, J Hertel2, A S Bruce2, D R Diduch3, S A Saliba2, W M Novicoff4, J M Hart5. 1. Department of Kinesiology. University of Virginia, Memorial Gymnasium Rm 206 210 Emmet St So, Charlottesville, VA, 22903, USA. Electronic address: stephan.bodkin@cuanschutz.edu. 2. Department of Kinesiology. University of Virginia, Memorial Gymnasium Rm 206 210 Emmet St So, Charlottesville, VA, 22903, USA. 3. Department of Orthopaedic Surgery. University of Virginia, 400 Ray C. Hunt Drive, Suite 330 PO Box 800159, 22908, Charlottesville, VA, USA. 4. Public Health Sciences, University of Virginia, P.O. Box 800717, Health System West Complex, Room 3193, Charlottesville, VA, 22908, USA. 5. Department of Kinesiology. University of Virginia, Memorial Gymnasium Rm 206 210 Emmet St So, Charlottesville, VA, 22903, USA; Department of Orthopaedic Surgery. University of Virginia, 400 Ray C. Hunt Drive, Suite 330 PO Box 800159, 22908, Charlottesville, VA, USA.
Abstract
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.
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.