Elevated pain-related fear of movement/reinjury, quadriceps weakness, and reduced IKDC score distinguish patients who are unable to return to preinjury sports participation because of fear of reinjury/lack of confidence. Despite low average pain ratings, fear of pain may influence function in this subgroup. Assessment of fear of reinjury, quadriceps strength, and self-reported function at 6 months may help identify patients at risk for not returning to sports at 1 year and should be considered for inclusion in return-to-sport guidelines.

STUDY DESIGN Cross-sectional cohort. OBJECTIVES (1) To examine differences in clinical variables (demographics, knee impairments, and self-report measures) between those who return to preinjury level of sports participation and those who do not at 1 year following anterior cruciate ligament reconstruction, (2) to determine the factors most strongly associated with return-to-sport status in a multivariate model, and (3) to explore the discriminatory value of clinical variables associated with return to sport at 1 year postsurgery. BACKGROUND Demographic, physical impairment, and psychosocial factors individually prohibit return to preinjury levels of sports participation. However, it is unknown which combination of factors contributes to sports participation status. METHODS Ninety-four patients (60 men; mean age, 22.4 years) 1 year post–anterior cruciate ligament reconstruction were included. Clinical variables were collected and included demographics, knee impairment measures, and self-report questionnaire responses. Patients were divided into “yes return to sports” or “no return to sports” groups based on their answer to the question, “Have you returned to the same level of sports as before your injury?” Group differences in demographics, knee impairments, and self-report questionnaire responses were analyzed. Discriminant function analysis determined the strongest predictors of group classification. Receiver-operating-characteristic curves determined the discriminatory accuracy of the identified clinical variables. RESULTS Fifty-two of 94 patients (55%) reported yes return to sports. Patients reporting return to preinjury levels of sports participation were more likely to have had less knee joint effusion, fewer episodes of knee instability, lower knee pain intensity, higher quadriceps peak torque-body weight ratio, higher score on the International Knee Documentation Committee Subjective Knee Evaluation Form, and lower levels of kinesiophobia. Knee joint effusion, episodes of knee instability, and score on the International Knee Documentation Committee Subjective Knee Evaluation Form were identified as the factors most strongly associated with self-reported return-to-sport status. The highest positive likelihood ratio for the yes-return-to-sports group classification (14.54) was achieved when patients met all of the following criteria: no knee effusion, no episodes of instability, and International Knee Documentation Committee Subjective Knee Evaluation Form score greater than 93. CONCLUSION In multivariate analysis, the factors most strongly associated with return-to-sport status included only self-reported knee function, episodes of knee instability, and knee joint effusion.

Background Laboratory-based studies on neuromuscular control after concussion and epidemiological studies suggest that concussion may increase the risk of subsequent musculoskeletal injury. Objective The purpose of this study was to determine if athletes have an increased risk of lower extremity musculoskeletal injury after return-to-play from a concussion. Methods Injury data were collected from 2006–2013 for men’s football and women’s basketball, soccer, and lacrosse at a NCAA Division I university. Ninety cases in 73 athletes (52 Male, 21 Female) of in-season concussion with return-to-play at least 30 days prior to the end of the season were identified. A period of up to 90 days of in-season competition following return-to-play was reviewed for time-loss injury. The same period was studied in up to two control athletes who were without a concussion within the prior year and were matched on sport, starting status, and position. Results Lower extremity musculoskeletal injuries occurred at a higher rate in the concussed athletes (45/90 or 50%) compared to the non-concussed athletes (30/148 or 20%) (p < 0.01). The odds of sustaining a musculoskeletal injury were 3.39 times higher in the concussed athletes (95% CI = 1.90, 6.05; p < 0.01). Overall, the number of days lost due to injury was similar between concussed and non-concussed athletes (Median = 9 vs 15, p = 0.41). Conclusions The results of this study demonstrate a relationship between concussion and an increased risk of lower extremity musculoskeletal injury after return to play, and may have implications for current medical practice standards regarding the evaluation and management of concussion injuries.

Psychosocial factors are potentially modifiable early after ACL reconstruction. Baseline psychosocial factor levels did not predict knee pain or function 12 weeks postoperatively. Interventions that increase self-efficacy for rehabilitation tasks or decrease fear of movement or reinjury may have potential to improve short-term outcomes for knee pain and function.

The experience of pain is believed to be influenced by social, cultural, environmental, psychological, and genetic factors. Despite this assertion, few studies have included clinically relevant pain phenotypes when investigating interactions among these variables. This study investigated whether psychological variables specific to fear-avoidance models and catechol-O-methyltransferase (COMT) genotype influenced pain ratings for a cohort of patients receiving operative treatment of shoulder pain. Patients (n = 58) completed questionnaires and had COMT genotype determined preoperatively. Then, shoulder pain ratings were collected 3-5 months post-operatively. This cohort consisted of 24 females and 34 males, with mean age of 50.3 (SD = 15.0) and pre-operative pain rating of 4.5/10 (SD = 1.8). The frequency of COMT diplotypes was 34 with "high COMT activity" (LPS group) and 24 with "low COMT activity" (APS/HPS group). Preliminary analysis indicated that of all the fear-avoidance variables considered (fear of pain, kinesiophobia, pain catastrophizing, and anxiety), only pain catastrophizing was a unique contributor to clinical pain ratings. A hierarchical regression model indicated that an interaction between pain catastrophizing and COMT diplotype contributed additional variance in pre-operative pain ratings. The pain catastrophizing × COMT diplotype interaction demonstrated predictive validity as patients with high pain catastrophizing and low COMT activity (APS/HPS group) were more likely (RR = 6.8, 95% CI = 2.8-16.7) to have post-operative pain ratings of 4.0/10 or higher. Our findings suggest that an interaction between pain catastrophizing and COMT diplotype has the potential to influence pain ratings in patients seeking operative treatment of their shoulder pain.

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Background:Many individuals do not resume unrestricted, preinjury sports participation after anterior cruciate ligament reconstruction, thus a better understanding of factors associated with function is needed. The purpose of this study was to investigate the association of knee impairment and psychological variables with function in subjects with anterior cruciate ligament reconstruction.Hypothesis:After controlling for demographic variables, knee impairment and psychological variables contribute to function in subjects with anterior cruciate ligament reconstruction.Study Design:Cross-sectional study; Level of evidence, 4a.Methods:Fifty-eight subjects with a unilateral anterior cruciate ligament reconstruction completed a standardized testing battery for knee impairments (range of motion, effusion, quadriceps strength, anterior knee joint laxity, and pain intensity), kinesiophobia (shortened Tampa Scale for Kinesiophobia), and function (International Knee Documentation Committee subjective form and single-legged hop test). Separate 2-step regression analyses were conducted with International Knee Documentation Committee subjective form score and single-legged hop index as dependent variables. Demographic variables were entered into the model first, followed by knee impairment measures and Tampa Scale for Kinesiophobia score.Results:A combination of pain intensity, quadriceps index, Tampa Scale for Kinesiophobia score, and flexion motion deficit contributed to the International Knee Documentation Committee subjective form score (adjusted r2 = 0.67; P < .001). Only effusion contributed to the single-legged hop index (adjusted r2 = 0.346; P = .002).Conclusion:Knee impairment and psychological variables in this study were associated with self-report of function, not a performance test.Clinical Relevance:The results support focusing anterior cruciate ligament reconstruction rehabilitation on pain, knee motion deficits, and quadriceps strength, as well as indicate that kinesiophobia should be addressed. Further research is needed to reveal which clinical tests are associated with performance testing.

Objective Post-traumatic knee osteoarthritis is prevalent after anterior cruciate ligament reconstruction. Biomarkers that identify individuals likely to develop osteoarthritis, especially symptomatic osteoarthritis, can help target preventative and therapeutic strategies. This study examined the magnitude and change over time in urinary CTX-II (uCTX-II) concentrations shortly after ACL reconstruction, and, secondarily, the associations with knee pain and function. Design Subjects were 28 patients with ACL reconstruction (ACLR) and 28 age- and sex-matched controls (CNTRL). Testing was conducted at 4 time points spaced 4 weeks apart (4, 8, 12 and 16 weeks post-operative in ACLR). Measures included demographics, urine samples, Numeric Pain Rating Scale (NPRS) and International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). uCTX-II concentrations were determined with competitive ELISA. uCTX-II concentrations at each time point in ACLR were compared to the mean concentration over time in CNTRL, with and without adjustment for body mass index (BMI). Changes over time in each measure and correlations between the slopes of change were examined. Results uCTX-II concentrations were significantly higher in ACLR than CNTRL through 16 weeks post-operative when adjusted for BMI. In ACLR, uCTX-II concentrations significantly decreased over time, and the slope was associated with NPRS (r =.406, p=.039) and IKDC-SKF (r = −.402, p = .034) slopes. Conclusion uCTX-II concentrations shortly after ACL reconstruction were elevated compared to controls and declined over time. Decreasing uCTX-II concentrations were associated with decreasing knee pain and improving function. uCTX-II may have a role as a prognostic marker following ACL reconstruction and warrants further investigation.