William D. Stanish

Psychological determinants of problematic outcomes following Total Knee Arthroplasty

ABSTRACT The primary objective of the present study was to examine the role of pain‐related psychological factors in predicting pain and disability following Total Knee Arthroplasty (TKA). The study sample consisted of 75 (46 women, 29 men) individuals with osteoarthritis of the knee who were scheduled for TKA. Measures of pain severity, pain catastrophizing, depression, and pain‐related fears of movement were completed prior to surgery. Participants completed measures of pain severity and self‐reported disability 6 weeks following surgery. Consistent with previous research, cross‐sectional analyses revealed significant correlations among measures of pre‐surgical pain severity, pain catastrophizing, depression and pain‐related fears of movement. Prospective analyses revealed that pre‐surgical pain severity and pain catastrophizing were unique predictors of post‐surgical pain severity (6‐week follow‐up). Pain‐related fears of movement were predictors of post‐surgical functional difficulties in univariate analyses, but not when controlling for pre‐surgical co‐morbidities (e.g. back pain). The results of this study add to a growing literature highlighting the prognostic value of psychological variables in the prediction of post‐surgical health outcomes. The results support the view that the psychological determinants of post‐surgical pain severity differ from the psychological determinants of post‐surgical disability. The results suggest that interventions designed to specifically target pain‐related psychological risk factors might improve post‐surgical outcomes.

Secondary Prevention of Work Disability: Community-Based Psychosocial Intervention for Musculoskeletal Disorders

Introduction: One objective of the present research was to examine the degree to which psychological risk factors could be reduced through participation in a community-based psychosocial intervention for work-related musculoskeletal disorders. A second objective was to examine whether psychosocial risk reduction had an effect on the probability of return to work. Methods: Participants were 215 Workers Compensation Board claimants with work-related musculoskeletal disorders who had been absent from work for an average of approximately 7 months (M = 28.8 weeks, range = 4–100 weeks) and were referred to a community-based multidisciplinary secondary prevention program in Nova Scotia, Canada. Results: In the current sample, 63.7% of participants returned to work within 4 weeks of treatment termination. The percentage reductions in targeted risk factors from pretreatment to posttreatment were as follows: catastrophizing (32%), depression (26%), fear of movement/re-injury (11%), and perceived disability (26%). Logistic regression indicated that elevated pretreatment scores on fear of movement and re-injury (OR = 0.58, 95% CI = 0.35–0.95) and pain severity (OR = 0.64, 95% CI = 0.43–0.96) were associated with a lower probability of return to work. A second logistic regression addressing the relation between risk factor reduction and return to work revealed that only reductions in pain catastrophizing (OR = 0.17, 95% CI = 0.07–0.46) were significant predictors of return to work. Conclusions: The results of the present study provide further evidence that risk factor reduction can impact positively on short term return to work outcomes. Significance: Outcomes of rehabilitation programs for work disability might be improved by incorporating interventions that specifically target catastrophic thinking. Community-based models of psychosocial intervention might represent a viable approach to the management of work disability associated with musculoskeletal disorders.

Neuromuscular and Lower Limb Biomechanical Differences Exist Between Male and Female Elite Adolescent Soccer Players During an Unanticipated Run and Crosscut Maneuver

Background Female athletes are 2 to 8 times more likely than male athletes to injure the anterior cruciate ligament during a noncontact athletic maneuver. Identifying anterior cruciate ligament injury risk factors in female athletes may help with the development of preventive training programs aimed at reducing injury rates. Hypothesis Differences between genders in lower limb kinematics, kinetics, and neuromuscular patterns will be identified in an adolescent soccer population during an unanticipated side-cut maneuver. Study Design Controlled laboratory study. Methods Forty-two elite adolescent soccer players (21 male and 21 female) performed an unanticipated side-cut maneuver, with the 3-dimensional kinematic, kinetic, and electromyographic lower limb data being analyzed using principal component analysis. Results The female athletes had higher gastrocnemius activity, normalized to maximal voluntary isometric contractions, and a mediolateral gastrocnemius activation imbalance that was not present in the male athletes during early stance to midstance of the side-cut. Female athletes demonstrated greater rectus femoris muscle activity throughout stance, and the only hamstring difference identified was a mediolateral activation imbalance in male athletes only. Female athletes performed the side-cut with less hip flexion and more hip external rotation and also generated a smaller hip flexion moment compared with the male athletes. Conclusion This is the first study to identify gender-related differences in gastrocnemius muscle activity during an unanticipated cutting maneuver. Clinical Relevance The increased and imbalanced gastrocnemius muscle activity, combined with increased rectus femoris muscle activity and reduced hip flexion angles and moments in female subjects, may all have important contributing roles in the higher noncontact ACL injury rates observed in female athletes.

Differential predictors of pain and disability in patients with whiplash injuries

The psychological predictors of pain and disability were examined in a sample of people who sustained whiplash injuries during rear-end motor vehicle accidents. Sixty-five patients referred to a specialty pain clinic with a diagnosis of whiplash injury completed measures of depression, anxiety, catastrophizing, pain and perceived disability. Regression analysis revealed that psychological variables accounted for 18% of the variance in pain ratings. The magnification subscale of the Pain Catastrophizing Scale was the only variable that contributed significant, unique variance to the prediction of pain. Psychological variables accounted for 37% of the variance in perceived disability scores. In the latter analysis, however, none of the independent variables contributed significant, unique variance to the prediction of perceived disability. Psychological variables accounted for significant variance in disability ratings, even when controlling for pain intensity. Discussion focuses on the need to draw clearer distinctions between determinants of pain and disability, and directions for interventions aimed at minimizing disability following whiplash injury are suggested.

Novel Scaffold-Based BST-CarGel Treatment Results in Superior Cartilage Repair Compared with Microfracture in a Randomized Controlled Trial

BACKGROUND Microfracture, the standard of care, is recognized to be an incomplete solution for cartilage damage. BST-CarGel, a chitosan-based medical device, is mixed with autologous whole blood and is applied to a microfractured cartilage lesion in which it physically stabilizes the clot and guides and enhances marrow-derived repair. An international, multicenter, randomized controlled trial was conducted to evaluate BST-CarGel treatment compared with microfracture alone in the repair of cartilage lesions in the knee. METHODS Eighty patients between the ages of eighteen and fifty-five years with a single, symptomatic focal lesion on the femoral condyles were randomized to BST-CarGel and microfracture treatment (n = 41) or microfracture treatment alone (n = 39). The primary end points of repair tissue quantity and quality at twelve months were assessed by quantitative three-dimensional magnetic resonance imaging measuring the degree of lesion filling and T2 relaxation time with use of standardized one and twelve-month posttreatment scans. The secondary end point at twelve months was clinical benefit determined with the Western Ontario and McMaster Universities Osteoarthritis Index. The tertiary end point was quality of life determined by the Short Form-36. Safety was assessed through the recording of adverse events. RESULTS Patient baseline characteristics were similar in the two groups, although baseline lesion areas were slightly larger on quantitative magnetic resonance imaging for the BST-CarGel group compared with the microfracture group. Blinded quantitative magnetic resonance imaging analysis demonstrated that, at twelve months, when compared with microfracture treatment alone, BST-CarGel treatment met both primary end points by achieving statistical superiority for greater lesion filling (p = 0.011) and more hyaline cartilage-like T2 values (p = 0.033). The lesion filling values were 92.8% ± 2.0% for the BST-CarGel treatment group and 85.2% ± 2.1% for the microfracture treatment group, and the mean T2 values were 70.5 ± 4.5 ms for the BST-CarGel treatment group and 85.0 ± 4.9 ms for the microfracture treatment group. Western Ontario and McMaster Universities Osteoarthritis Index subscales for pain, stiffness, and function yielded equivalent improvement for both groups at twelve months, which were significant (p < 0.0001) from baseline. Treatment safety profiles were considered comparable. CONCLUSIONS At twelve months, BST-CarGel treatment resulted in greater lesion filling and superior repair tissue quality compared with microfracture treatment alone. Clinical benefit was equivalent between groups at twelve months, and safety was similar.

The role of presurgical expectancies in predicting pain and function one year following total knee arthroplasty

Summary Patients’ behavioral outcome expectancies assessed presurgically predicted pain severity and physical function 1 year after total knee arthroplasty (TKA) and partially mediated the relation between catastrophizing and TKA outcomes. Abstract The present study examined the prospective value of response expectancies (ie, pain, sleep) and behavioral outcome expectancies (ie, return to function) in the prediction of pain severity and functional limitations 12 months after total knee arthroplasty (TKA). The study sample consisted of 120 individuals (73 women, 47 men) with osteoarthritis of the knee who were scheduled for TKA. Measures of expectancies, pain severity, pain catastrophizing, pain‐related fears of movement, and depression were completed prior to surgery. Participants also completed measures of pain severity and functional limitations 12 months following surgery. Analyses revealed that behavioral outcome expectancies were stronger predictors of follow‐up pain and functional limitations than response expectancies. Consistent with previous research, analyses also revealed that pain catastrophizing, pain‐related fear of movement, and depression predicted follow‐up pain and function. In a multivariate analysis, only pain catastrophizing contributed significant unique variance to the prediction of follow‐up pain and function. Behavioral outcome expectancies partially mediated the relation between catastrophizing and follow‐up pain and function. The relation between catastrophizing and follow‐up pain severity and functional limitations remained significant even when controlling for behavioral outcome expectancies. The results suggest that interventions designed to specifically target behavioral outcome expectancies and catastrophizing might improve post‐surgical outcomes.

Musculoskeletal injury in the masters runners.

ObjectiveTo determine if injury patterns and risk factors for injury differ between masters and younger runners. DesignRetrospective survey. SettingHood to Coast running relay, Oregon, USA. ParticipantsA total of 2886 runners consented to participate and completed the survey. Ninety-four (2712/2886) percent completed the survey electronically and 6% (174/2886) manually. Master runners (≥40 years) made up 34% of the population. InterventionThe survey was distributed to all participants in the largest running relay in North America. Runners reported on training patterns, injury location, and diagnosis over the previous year. Main Outcome MeasuresDescriptive statistics and χ2 analysis were used to detect differences in injury rate and location between masters and younger runners. Multivariate logistic regression models were used to identify risk factors for injury for each group. ResultsThe injury rate for the entire population was 46%. Significantly more masters runners were injured than younger runners (P<0.05). More masters runners suffered multiple injuries than younger runners (P<0.001). Significantly more masters runners were male, had 7 or more years of running experience, run more than 30 miles/wk, 6 or more times/week and wear orthotics than younger runners (P<0.001). The knee and foot were the most common locations of injury for both groups. The prevalence of soft-tissue-type injuries to the calf, achilles, and hamstrings was greater in masters runners than their younger counterparts (P<0.001). Younger runners suffered more knee and leg injuries than masters runners (P<0.005). Running more times/wk increased the risk of injury for both groups. ConclusionsThere were subtle differences in injury rate and location between masters runners and younger runners, which may reflect differences in training intensity.

Histological analysis of achilles tendons in an overuse rat model

The purpose of this study was to design an animal model that induces histological changes in Achilles tendons consistent with those cited in the literature for human Achilles tendon disease. Sprague‐Dawley rats were subjected to 10° uphill treadmill running on a custom‐designed rodent treadmill and at a speed of 17 meters per minute for 1 h, five times per week, over a 12‐week treatment period. Subsequent histological analysis revealed alterations in the rat Achilles tendon that were generally consistent with those described in the literature for diseased human tendon tissues. These features include: decreased collagen fiber organization, more intense collagen staining, and increased cell nuclei numbers. Interestingly, though, immunohistochemical cell typing suggests that the observed increased cellularity does not include a significant inflammatory component but is secondary to increased numbers of endothelial cells (i.e., vascularization) and fibroblasts. These histological features likely represent a biological repair/remodeling response resulting from overuse running.

Co-activation differences in lower limb muscles between asymptomatic controls and those with varying degrees of knee osteoarthritis during walking

BACKGROUND Increased muscle co-activation during gait has been identified as a neuromuscular alteration associated with knee osteoarthritis, however levels of co-activation among different osteoarthritis severity have not been established. The purpose of this study was to determine if differences in co-activation could be detected among asymptomatic controls, those with moderate and those with severe osteoarthritis using a co-activation index and a pattern recognition technique. METHODS Surface electromyograms from vastus lateralis and medialis, lateral and medial hamstring and gastrocnemius pairs were recorded from 63 asymptomatic, 59 moderate and 48 severe osteoarthritic subjects during self-selected walking. A co-activation index was calculated over the initial stance for four medial and lateral muscle pairs. The four co-activation indices were tested among groups using a one factor ANOVA (alpha=0.05). Gait waveform pattern recognition procedures were applied to yield a principal pattern, scored for each muscle site and subject. A mixed model ANOVA (group-muscle) tested for principal pattern score differences. FINDINGS A significant group effect was found (P<0.05) for all four co-activation indices. Principal pattern one captured the amplitude and general shape of activity throughout the entire stance phase. ANOVA revealed a significant (P<0.05) group by muscle interaction for the principal pattern scores. Significant differences were found among all three groups and between the two osteoarthritic groups for both measures. INTERPRETATION The co-activation indices and principal patterns identified that lateral site differences occurred among all three groups with medial site differences between the two osteoarthritic groups. These findings suggest that measures of muscle co-activity provide additional information related to knee osteoarthritis severity.

Shoulder arthroscopy and nerve injury: Pitfalls and prevention

Shoulder arthroscopy has become a very useful diagnostic and therapeutic modality. Unfortunately, like many other invasive procedures it can have complications. One of the most worrisome complications, for both the patient and surgeon, is that of nerve injury. Nerve injury during shoulder arthroscopy is often a transient phenomenon although a more severe injury has been documented. We review much of the literature on this subject and discuss some of the many pitfalls and preventative strategies that have been reported.