The effect of factors from different time points on psychological readiness following ACL reconstruction.

OBJECTIVE: The purpose of this study was to examine factors correlated with psychological readiness to return to activity after ACLR. DESIGN: cross sectional study. SETTING: controlled laboratory. PARTICIPANTS: 164 patients (82 M/82 F, 22.5 ± 8.9yr, 171.6 ± 11.0 cm, 77.4 ± 18.6 kg, 8.6 ± 3.4 months post-ACLR) participated in this study after a primary, isolated, and uncomplicated ACLR. MAIN OUTCOME MEASURES: ACL Return to Sport Index (ACL-RSI). RESULTS: ACL-RSI scores demonstrated a weak positive correlation with activity level at the time of injury and a fair positive correlation with activity level at the time of post-operative testing (p-values: 0.004, <0.001). ACL-RSI scores showed a statistically significant fair negative correlation with pain and a moderate negative correlation with kinesiophobia during rehabilitation (p-values: <0.001, <0.001). There was no statistical significance between ACL-RSI and the surgical variables (p-value range: 0.10-0.61). CONCLUSIONS: Outcomes from testing during postoperative rehabilitation were most correlated with psychological readiness to return to activity after ACLR. Increased pain and kinesiophobia were associated with a decreased psychological readiness. Increased activity level prior to injury and activity level at the time of testing during rehabilitation were both correlated with increased psychological readiness. Psychological readiness to return to activity may need to be customized based on potentially modifiable patient-specific factors during the post-operative rehabilitation.

Associations Between Race & Socioeconomic Status, Lower Extremity Strength, and Patient Reported Outcomes Following Anterior Cruciate Ligament Reconstruction.

CONTEXT: There are significant disparities in access to health care, but there are limited data about the impact of race and socioeconomic status (SES) on postoperative outcomes following anterior cruciate ligament (ACL) reconstruction (ACLR) surgery. OBJECTIVE: To identify associations between area deprivation index (ADI), strength measures and patient-reported outcomes (PROs) following ACLR as well as to examine differences in outcomes between race, sex, and race. DESIGN: Case control study in a single hospital setting. SETTING: Database secondary analysis. PATIENTS OR OTHER PARTICIPANTS: Data was collected from 340 patients who underwent primary, isolated, unilateral ACLR. MAIN OUTCOME MEASURES: Strength measures and PROs were obtained at patients' postoperative assessments at approximately six months post-surgery. Area Deprivation Index values were calculated on each patient's census tract, determined through medical records review. Correlations were conducted to determine the relationship between ADI and KOOS measures, IKDC, and limb symmetry on strength measurements. The racial composition of the sample was heavily skewed and was excluded from statistical analyses. RESULTS: ADI was weakly correlated with IKDC (ρ=0.11, p=0.04) outcomes, with more disadvantaged patients reporting better quality of life and knee function. ADI was not correlated with other outcomes of interest. The median ADI value of the sample was 32 (range 1-86 [IQR 19-47]). CONCLUSIONS: Our study revealed a weak correlation between higher levels of socioeconomic disadvantage as measured by ADI and improved subjective assessment of knee function and quality of life as measured by IKDC. These findings are contrary to what other studies on this subject have found and highlight the importance of further research into the impact of SES and other social determinants of health on post ACLR outcomes.

Automated Versus Traditional Scoring Agreeability During the Balance Error Scoring System.

CONTEXT: The Balance Error Scoring System (BESS) is a commonly used clinical tool to evaluate postural control that is traditionally performed through visual assessment and subjective evaluation of balance errors. The purpose of this study was to evaluate an automated computer-based scoring system using an instrumented pressure mat compared to the traditional human-based manual assessment. DESIGN: A descriptive cross-sectional study design was used to evaluate the performance of the automated versus human BESS scoring methodology in healthy individuals. METHODS: Fifty-one healthy active participants performed BESS trials following standard BESS procedures on an instrumented pressure mat (MobileMat, Tekscan Inc). Trained evaluators manually scored balance errors from frontal and sagittal plane video recordings for comparison to errors scored using center of force measurements and an automated scoring software (SportsAT, version 2.0.2, Tekscan Inc). A linear mixed model was used to determine measurement discrepancies across the 2 methods. Bland-Altman analyses were conducted to determine limit of agreement for the automated and manual scoring methods. RESULTS: Significant differences between the automated and manual errors scored were observed across all conditions (P < .05), excluding bilateral firm stance. The greatest discrepancy between scoring methods was during the tandem foam stance, while the smallest discrepancy was during the tandem firm stance. CONCLUSION: The 2 methods of BESS scoring are different with wide limits of agreement. The benefits and risks of each approach to error scoring should be considered when selecting the most appropriate metric for clinical use or research studies.

Knee extensor torque-velocity relationships following anterior cruciate ligament reconstruction.

BACKGROUND: The inherent nature of the torque-velocity relationship is the inverse nature between the velocity of muscle contraction and torque production and is an indication of muscle function. The purpose of this study was to characterize the torque-velocity relationship in the quadriceps following anterior cruciate ligament reconstruction compared to healthy limbs. METHODS: 681 participants were included, 493 of which were patients at least four months following anterior cruciate ligament reconstruction (23.2 ± 10.08 yr, 6.6 ± 5.37 months post-surgery) and 188 were healthy participants (21.6 ± 3.77 yr). A subset of 175 post-surgical participants completed a repeated visit (8.1 ± 1.71 months post-surgery). Participants completed isokinetic knee extension at 90°/s and 180°/s. A one-way ANOVA was used to compare torque velocity relationships by limb type (surgical, contralateral, healthy). Paired samples t-tests were conducted to analyze the torque-velocity relationship across limbs and across time. FINDINGS: There was a large effect for limb type on torque-velocity (F(2, 1173) = 146.08, p < 0.001, η2 = 0.20). Surgical limbs demonstrated significantly lower torque-velocity relationships compared to the contralateral limbs (ACLR: 0.26 Nm/kg, contralateral:0.55 Nm/kg, p < 0.001, d = 1.18). Healthy limbs had similar torque-velocity relationships bilaterally (dominant limb: 0.48 Nm/kg, non-dominant limb: 0.49 Nm/kg, p = 0.45). The torque velocity relationship for the involved limb significantly increased in magnitude over time (+0.11 Nm/kg, p < 0.001, d = -0.61) while the contralateral limb torque-velocity relationship remained stable over time (0.0 Nm/kg difference, p = 0.60). INTERPRETATION: Following surgery, the knee extensors appear to have altered torque-velocity relationships compared to contralateral and healthy limbs. This may indicate a specific target for assessment and rehabilitation following surgery.

Hip Strength Recovery After Anterior Cruciate Ligament Reconstruction.

Background: Return-to-play (RTP) assessment after anterior cruciate ligament reconstruction (ACLR) rarely includes hip strength. Hypothesis: It was hypothesized that (1) patients after ACLR will have weaker hip abduction (AB) and adduction (AD) strength compared with the contralateral limb, with larger deficits in women, (2) there will be a correlation between hip and thigh strength ratios and patient-reported outcomes (PROs), and (3) hip AB and AD strength will improve over time. Study Design: Descriptive laboratory study. Methods: Included were 140 patients (74 male, 66 female; mean age, 24.16 ± 10.82 years) who underwent RTP assessment at 6.1 ± 1.6 months after ACLR; 86 patients underwent a second assessment at 8.2 ± 2.2 months. Hip AB/AD and knee extension/flexion isometric strength were measured and normalized to body mass, and PRO scores were collected. Strength ratios (hip vs thigh), limb differences (injured vs uninjured), sex-based differences, and relationships between strength ratios and PROs were determined. Results: Hip AB strength was weaker on the ACLR limb (ACLR vs contralateral: 1.85 ± 0.49 vs 1.89 ± 0.48 N·m/kg; P < .001) and hip AD torque was stronger (ACLR vs contralateral: 1.80 ± 0.51 vs 1.76 ± 0.52 N·m/kg; P = .004), with no sex-by-limb interaction found. Lower hip-to-thigh strength ratios of the ACLR limb were correlated with higher PRO scores (r = -0.17 to -0.25). Over time, hip AB strength increased in the ACLR limb more than in the contralateral limb (P = .01); however, the ACLR limb remained weaker in hip AB at visit 2 (ACLR vs contralateral: 1.88 ± 0.46 vs 1.91 ± 0.45 N·m/kg; P = .04). In both limbs, hip AD strength was greater at visit 2 than visit 1 (ACLR: 1.82 ± 0.48 vs 1.70 ± 0.48 N·m/kg; contralateral: 1.76 ± 0.47 vs 1.67 ± 0.47 N·m/kg; P < .01 for both). Conclusion: The ACLR limb had weaker hip AB and stronger AD compared with the contralateral limb at initial assessment. Hip muscle strength recovery was not influenced by sex. Hip strength and symmetry improved over the course of rehabilitation. Although strength differences across limbs were minor, the clinical importance of these differences is still unknown. Clinical Relevance: The evidence provided highlights the need to integrate hip strength into RTP assessments to identify hip strength deficits that may increase reinjury or lead to poor long-term outcomes.

Comparison of Patient-Reported Outcomes, Strength, and Functional Performance in Primary Versus Revision Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Clinical outcomes after revision anterior cruciate ligament reconstruction (ACLR) are not well understood. HYPOTHESIS: Patients undergoing revision ACLR would demonstrate worse patient-reported outcomes and worse limb symmetry compared with a cohort undergoing primary ACLR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: 672 participants (373 with primary ACLR, 111 with revision ACLR, and 188 uninjured) completed functional testing at a single academic medical center. Descriptive information, operative variables, and patient-reported outcomes (International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Tegner Activity Scale score) were assessed for each patient. Quadriceps and hamstring strength tests were conducted using a Biodex System 3 Dynamometer. Single-leg hop for distance, triple hop test, and the 6-m timed hop test were also assessed. Limb symmetry index (LSI) between the ACLR limb and contralateral limb was calculated for strength and hop testing. Normalized peak torque (N·m/kg) was calculated for strength testing. RESULTS: No differences were found in group characteristics, excluding body mass (P < .001), or in patient-reported outcomes. There were no interactions between revision status, graft type, and sex. Knee extension LSI was inferior (P < .001) in participants who had undergone primary (73.0% ± 15.0%) and revision (77.2% ± 19.1%) ACLR compared with healthy, uninjured participants (98.8% ± 10.4%). Knee flexion LSI was inferior (P = .04) in the primary group (97.4% ± 18.4%) compared with the revision group (101.9% ± 18.5%). Difference in knee flexion LSI between the uninjured and primary groups, as well as between the uninjured and revision groups, did not reach statistical significance. Hop LSI outcomes were significantly different across all groups (P < .001). Between-group differences in extension in the involved limb (P < .001) were noted, as the uninjured group exhibited stronger knee extension (2.16 ± 0.46 N·m/kg) than the primary group (1.67 ± 0.47 N·m/kg) and the revision group (1.78 ± 0.48 N·m/kg). As well, differences in flexion in the involved limb (P = .01) were found, as the revision group exhibited stronger knee flexion (1.06 ± 0.25 N·m/kg) than the primary group (0.97 ± 0.29 N·m/kg) and the uninjured group (0.98 ± 0.24 N·m/kg). CONCLUSION: At 7 months postoperatively, patients who had undergone revision ACLR did not demonstrate inferior patient-reported outcomes, limb symmetry, strength, or functional performance compared with patients who had undergone primary ACLR. Patients who had undergone revision ACLR exhibited greater strength and LSI than their counterparts with primary ACLR, but these parameters were still inferior to those of uninjured controls.