Personalized Reference Values for the Two-Minute Walk Test: An Analysis of Cross-Sectional Data From the National Institutes of Health Toolbox Study.

OBJECTIVES: To develop reference values for the Two-Minute Walk Test (TMWT) via 2 previously untested methods: (1) smooth age-based statistical models and (2) a neighbors-based approach accounting for age, sex, and height. DESIGN: Cross-sectional observational study. SETTING: National Institutes of Health Toolbox study sites across the United States. PARTICIPANTS: A total of 1385 healthy, community dwelling adult participants (age 18-85 years) in the National Institutes of Health Toolbox study were included in this analysis. INTERVENTION: None. MAIN OUTCOME MEASURES: Reference values for TMWT were generated using 2 approaches: (1) Generalized Additive Models for Location Scale and Shape, wherein TMWT values were modeled as a smooth function of age, and (2) a semiparametric neighbors-based approach. The performance of references values was then adjudicated by examining precision (ie, the average interquartile or interdecile range of reference values), and coverage (ie, the proportion of realized values included within a given inter-percentile interval). Agreement between methods was examined by intraclass correlation coefficient. RESULTS: Neighbors-based reference values demonstrated a smaller average interquartile range (149 ft; 95% confidence interval [CI], 146-152 ft), compared with age-based reference values (158 ft; 95% CI, 155-162 ft), but similar average interdecile range (neighbors-based: 369 ft; 95% CI, 360-377 ft; age-based: 374 ft; 95% CI, 366-383 ft). Coverage appeared accurate via both approaches. Agreement between approaches was high (intraclass correlation coefficient=0.96), although differences were apparent on a case-by-case basis. CONCLUSIONS: Both age-based and neighbors-based reference values offer viable options for interpreting a person's TMWT performance. In this analysis, the neighbors-based approach (adjusting for height) yielded potentially clinically relevant differences in reference values for persons at extremes of height.

Determination of Pain Phenotypes in Knee Osteoarthritis Using Latent Profile Analysis.

OBJECTIVE: To identify clinical phenotypes of knee osteoarthritis (OA) using measures from the following domains: 1) multimorbidity; 2) psychological distress; 3) pain sensitivity; and 4) knee impairment or pathology. DESIGN: Data were collected from 152 people with knee OA and from 31 pain-free individuals. In participants with knee OA, latent profile analysis (LPA) was applied to the following measures: normalized knee extensor strength, Functional Comorbidity Index (FCI), Pain Catastrophizing Scale (PCS), and local (knee) pressure pain threshold. Comparisons were performed between empirically derived phenotypes from the LPA and healthy older adults on these measures. Comparisons were also made between pheonotypes on pain intensity, functional measures, use of health care, and history of knee injury. RESULTS: LPA resulted in a four-group solution. Compared with all other groups, group 1 (9% of the study population) had higher FCI scores. Group 2 (63%) had elevated pain sensitivity and quadriceps weakness relative to group 4 and healthy older adults. Group 3 (11%) had higher PCS scores than all other groups. Group 4 (17%) had greater leg strength, except relative to healthy older adults, and reduced pain sensitivity relative to all groups. Groups 1 and 3 demonstrated higher pain and worse function than other groups, and group 4 had higher rates of knee injury. CONCLUSION: Four phenotypes of knee OA were identified using psychological factors, comorbidity status, pain sensitivity, and leg strength. Follow-up analyses supported the replicability of this phenotype structure, but future research is needed to determine its usefulness in knee OA care.

Reference chart for knee flexion following total knee arthroplasty: a novel tool for monitoring postoperative recovery.

BACKGROUND: Clinicians and patients lack an evidence-based framework by which to judge individual-level recovery following total knee arthroplasty (TKA) surgery, thus impeding personalized treatment approaches for this elective surgery. Our study aimed to develop and validate a reference chart for monitoring recovery of knee flexion following TKA surgery. METHODS: Retrospective analysis of data collected in routine rehabilitation practice for patients following TKA surgery. Reference charts were constructed using Generalized Additive Models for Location Scale and Shape. Various models were compared using the Schwarz Bayesian Criterion, Mean Squared Error in 5-fold cross validation, and centile coverage (i.e. the percent of observed data represented below specified centiles). The performance of the reference chart was then validated against a test set of patients with later surgical dates, by examining the centile coverage and average bias (i.e. difference between observed and predicted values) in the test dataset. RESULTS: A total of 1173 observations from 327 patients were used to develop a reference chart for knee flexion over the first 120 days following TKA. The best fitting model utilized a non-linear time trend, with smoothing splines for median and variance parameters. Additionally, optimization of the number of knots in smoothing splines and power transformation of time improved model fit. The reference chart performed adequately in a test set of 171 patients (377 observations), with accurate centile coverage and minimal average bias (< 3 degrees). CONCLUSION: A reference chart developed with clinically collected data offers a new approach to monitoring knee flexion following TKA.

Characteristics of young and lower functioning patients following total knee arthroplasty: a retrospective study.

BACKGROUND: Rates of total knee arthroplasty (TKA) procedures in younger, more medically complex patients have dramatically increased over the last several decades. No study has examined categorization of lower and higher functioning subgroups within the TKA patient population. Our study aimed to determine preoperative characteristics of younger patients who are lower functioning following TKA. METHODS: Patients were categorized into higher and lower functioning subgroups defined using a median split of 1) postoperative Timed Up and Go (TUG) test times and 2) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale scores. A split in age (65 years) was used to further classify patients into four categories: younger lower functioning, younger higher functioning, older lower functioning and older higher functioning. Measures from preoperative domains of health, psychological, physical performance and pain severity were examined for between-group differences. RESULTS: Comparing mean values, the younger lower functioning subgroup using the TUG had significantly weaker knee extensor, slower gait speed, higher body mass index and greater pain compared to other subgroups. The younger lower functioning subgroup using the WOMAC physical function subscale demonstrated higher pain levels and Coping Strategies Questionnaire-Catastrophizing Subscale scores compared to the older lower functioning subgroup. CONCLUSIONS: Poorer preoperative physical performance and pain severity appear to have the largest influence on early postoperative TKA recovery in younger lower functioning patients relative to both younger and older higher functioning patients.

Progressive multi-component home-based physical therapy for deconditioned older adults following acute hospitalization: a pilot randomized controlled trial.

OBJECTIVE: To determine whether a progressive multicomponent physical therapy intervention in the home setting can improve functional mobility for deconditioned older adults following acute hospitalization. DESIGN: Randomized controlled trial. SETTING: Patient homes in the Denver, CO, metropolitan area. PARTICIPANTS: A total of 22 homebound older adults age 65 and older (mean ± SD; 85.4 ±7.83); 12 were randomized to intervention group and 10 to the control group. INTERVENTION: The progressive multicomponent intervention consisted of home-based progressive strength, mobility and activities of daily living training. The control group consisted of usual care rehabilitation. MEASUREMENTS: A 4-meter walking speed, modified Physical Performance Test, Short Physical Performance Battery, 6-minute walk test. RESULTS: At the 60-day time point, the progressive multicomponent intervention group had significantly greater improvements in walking speed (mean change: 0.36 m/s vs. 0.14 m/s, p = 0.04), modified physical performance test (mean change: 6.18 vs. 0.98, p = 0.02) and Short Physical Performance Battery scores (mean change: 2.94 vs. 0.38, p = 0.02) compared with the usual care group. The progressive multicomponent intervention group also had a trend towards significant improvement in the 6-minute walk test at 60 days (mean change: 119.65 m vs. 19.28 m; p = 0.07). No adverse events associated with intervention were recorded. CONCLUSIONS: The progressive multicomponent intervention improved patient functional mobility following acute hospitalization more than usual care. Results from this study support the safety and feasibility of conducting a larger randomized controlled trial of progressive multicomponent intervention in this population. A more definitive study would require 150 patients to verify these conclusions given the effect sizes observed.

Does Tourniquet Use in TKA Affect Recovery of Lower Extremity Strength and Function? A Randomized Trial.

BACKGROUND: Tourniquet use during total knee arthroplasty (TKA) improves visibility and reduces intraoperative blood loss. However, tourniquet use may also have a negative impact on early recovery of muscle strength and lower extremity function after TKA. QUESTIONS/PURPOSES: The purpose of this study was (1) to determine whether tourniquet use affects recovery of quadriceps strength (primary outcome) during the first 3 postoperative months; and (2) to examine the effects of tourniquet application on secondary outcomes: voluntary quadriceps activation, hamstring strength, unilateral limb balance as well as the effect on operative time and blood loss. METHODS: Twenty-eight patients (mean age 62 ± 6 years; 16 men) undergoing same-day bilateral TKA (56 lower extremities) were enrolled in a prospective, randomized study. Subjects were randomized to receive a tourniquet-assisted knee arthroplasty on one lower extremity while the contralateral limb underwent knee arthroplasty without extended tourniquet use. In the former group, the tourniquet was inflated just before the incision was made and released after cementation; in the latter group, a tourniquet was not used (10 of 28 [36%]) or inflated only during component cementation (18 of 28 [64%]). The choice of no tourniquet or use just during cementation was based on surgeon choice, because some surgeons felt a tourniquet during cementation was necessary to achieve a dry surgical field to maximize cement fixation. A median parapatellar approach and the identical posterior-stabilized TKA design were used by all four fellowship-trained knee surgeons involved. Isometric quadriceps strength, hamstring strength, voluntary quadriceps activation, and unilateral balance were assessed preoperatively, 3 weeks, and 3 months after bilateral knee arthroplasty. Other factors, including pain, range of motion, and lower extremity girth, were assessed for descriptive purposes at each of these time points as well as on the second postoperative day. RESULTS: Quadriceps strength was slightly lower in the tourniquet group compared with the no-tourniquet group (group difference = 11.27 Nm [95% confidence interval {CI}, 2.33-20.20]; p = 0.01), and these differences persisted at 3 months after surgery (group difference = 9.48 Nm [95% CI, 0.43-18.54]; p = 0.03). Hamstring strength did not differ between groups at any time point nor did measures of quadriceps voluntary activation or measures of unilateral balance ability. There was less estimated intraoperative blood loss in the tourniquet group (84 ± 26 mL) than in the no-tourniquet group (156 ± 63 mL) (group difference = -74 mL [95% CI, -100 to -49]; p < 0.001). However, there was no difference in total blood loss between the groups (group difference = -136 mL [95% CI, -318 to 45]; p = 0.13). CONCLUSIONS: Patients who underwent TKA using a tourniquet had diminished quadriceps strength during the first 3 months after TKA, the clinical significance of which is unclear. Future studies may be warranted to examine the effects of tourniquet use on long-term strength and functional outcomes. LEVEL OF EVIDENCE: Level I, therapeutic study.

Corticospinal and intracortical excitability of the quadriceps in patients with knee osteoarthritis.

Deficits in voluntary activation of the quadriceps muscle are characteristic of knee osteoarthritis (OA), contributing to the quadriceps weakness that is also a hallmark of the disease. The mechanisms underlying this central activation deficit (CAD) are unknown, although cortical mechanisms may be involved. Here, we utilize transcranial magnetic stimulation (TMS) to assess corticospinal and intracortical excitability in patients with knee OA and in a comparably aged group of healthy older adults, to quantify group differences, and to examine associations between TMS measures and pain, quadriceps strength, and CAD. Seventeen patients with knee OA and 20 healthy controls completed testing. Motor evoked potentials were measured at the quadriceps by superficial electromyographic recordings. Corticospinal excitability was assessed by measuring resting motor threshold (RMT) to TMS stimulation of the quadriceps representation at primary motor cortex, and intracortical excitability was assessed via paired-pulse paradigms for short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). No statistically significant differences between patients with knee OA and healthy controls were found for RMT, SICI or ICF measures (p > 0.05). For patients with knee OA, there were significant associations observed between pain and RMT, as well as between pain and ICF. No associations were observed between CAD and measures of corticospinal or intracortical excitability. These data suggest against direct involvement of corticospinal or intracortical pathways within primary motor cortex in the mechanisms of CAD. However, pain is implicated in the neural mechanisms of quadriceps motor control in patients with knee OA.

The impact of being overweight or obese on 12 month clinical recovery in patients following lumbar microdiscectomy for radiculopathy.

BACKGROUND CONTEXT: The proportion of patients who undergo lumbar microdiscectomy due to lumbar radiculopathy who are also overweight or obese is high. However, whether high body mass index (BMI) affects clinical outcomes is not well-studied. PURPOSE: To investigate the difference in the clinical course between normal weight, overweight, and obese patients with radiculopathy who underwent lumbar microdiscectomy followed by physical therapy and to evaluate whether high BMI is associated with poor recovery. STUDY DESIGN/SETTING: A prospective cohort study with a 12-month follow-up was conducted in a multidisciplinary clinic. PATIENT SAMPLE: We included 583 patients (median [IQR] age: 45 [35-52] years; 41% female) with clinical signs and symptoms of lumbar radiculopathy, consistent with magnetic resonance imaging findings, who underwent microdiscectomy followed by postoperative physical therapy. OUTCOME MEASURES: Outcomes were leg pain and back pain intensity measured with a visual analogue scale, disability measured with the Roland Morris Disability Questionnaire at 3 and 12-month follow-ups, and complications. METHODS: Patients were classified as being normal weight (46.9%), overweight (38.4%), or obese (14.7%). A linear mixed-effects model was used to assess the difference in the clinical course of pain and disability between the three BMI categories. The association between BMI and outcomes was evaluated using univariable and multivariable logistic regression analyses. RESULTS: All three patient groups experienced a significant improvement in leg pain, back pain, and disability over 3 and 12-month follow-up. Patients who were overweight, obese, or normal weight experienced comparable leg pain (p=.14) and disability (p=.06) over the clinical course (p=.14); however, obese patients experienced higher back pain (MD=-6.81 [95%CI: -13.50 to -0.14]; p=.03). The difference in back pain scores was not clinically relevant. CONCLUSIONS: In the first year following lumbar microdiscectomy, patients demonstrated clinical improvements and complications that were unrelated to their preoperative BMI.

Development and alpha testing of a patient shared decision aid for prosthesis design for new lower limb prosthesis users.

BACKGROUND: After lower limb amputation, several prosthesis design options exist. However, prosthesis design decisions do not always reflect a prosthesis user's needs, values, and preferences. OBJECTIVE: To develop a patient decision aid (PDA) prototype for prosthetists and new prosthesis users facing prosthesis design decisions after lower limb amputation, and to assess its usability, accuracy, and comprehensibility. STUDY DESIGN: Exploratory mixed methods. METHODS: PDA development was informed by a qualitative needs assessment and guided by the International Patient Decision Aid Standards. The PDA was evaluated by steering groups of experienced prosthesis users and prosthetic professionals (prosthetists and researchers) to test usability, accuracy, and comprehensibility through focus groups, individual interviews, and rating on a Likert scale ranging from 1 to 10. RESULTS: The resulting PDA included 6 sections: (1) Amputation and Early Recovery, (2) Communication, (3) Values, (4) Prosthesis Design, (5) Preferences, and (6) Prosthetic Journey. Usability, accuracy, and comprehensibility were rated as 9.2, 9.6, and 9.6, respectively, by prosthetic professionals, and 9.4, 9.6, and 9.6, respectively, by prosthesis users. DISCUSSION: The PDA incorporated guidance by relevant stakeholders and was rated favorably, emphasizing a need for shared decision-making support in prosthesis design. One challenge was determining the amount of information in the PDA, highlighting the diversity in end users' informational needs. Future iterations of the PDA should undergo beta testing in clinical settings. CONCLUSIONS: A standardized, iterative method was used to develop a PDA for new lower limb prosthesis users and prosthetists when considering prosthesis design decisions. The PDA was considered useable, accurate, and comprehensible.

Understanding decision-making in prosthetic rehabilitation by prosthetists and people with lower limb amputation: a qualitative study.

PURPOSE: Little has been published about the process of decision-making between prosthetists and people with lower limb amputation (LLA). The purpose of this study is to identify decisions and factors influencing decision-making in prosthetic rehabilitation from the perspectives of prosthetists and prosthesis users, to identify barriers and opportunities for shared decision-making (SDM). METHODS: Qualitative semi-structured individual interviews were conducted with 13 prosthetists and 14 prosthesis users from three clinics in three states of the Rocky Mountain and Southwest regions of the United States. Transcripts were analyzed using thematic analysis. RESULTS: Four main themes were identified: perceived decision points, importance of relationship, balancing competing priorities, and experience. Contrasts between perceptions of prosthetists and prosthesis users were related to prosthesis design decisions, and the purpose of communication (e.g., goals for a prosthesis vs. goals informing prosthesis design). Both prosthetists and prosthesis users described balancing priorities that contribute to prosthetic rehabilitation decisions, and the role of experience for informing realistic expectations and preferences necessary for participating in decision-making. CONCLUSION: Opportunities for improving SDM between prosthetists and prosthesis users include (1) clarifying key rehabilitation decisions, (2) identifying the purpose of initial communications, (3) support for balancing priorities, and (4) utilizing experience to achieve informed preferences.IMPLICATIONS FOR REHABILITATIONMany people with lower limb amputation experience poor physical function and psychosocial outcomes, which may be further compounded by under informed prosthesis-user expectations for function with a prosthesis.Shared decision-making offers an opportunity for improving realistic prosthesis-user expectations, reducing healthcare costs, and improving prosthesis-user satisfaction and adherence to care plans.Opportunities for improving shared decision-making between prosthetists and prosthesis-users include (1) clarifying key rehabilitation decisions, (2) identifying the purpose of initial communications, (3) support for balancing priorities, and (4) utilizing experience to achieve informed preferences.

Improving shared decision-making for prosthetic care: A qualitative needs assessment of prosthetists and new lower-limb prosthesis users.

BACKGROUND: Prosthesis design is complex and multiple appropriate options exist for any individual with lower-limb amputation. However, there is insufficient evidence for guiding decision-making. Shared decision-making (SDM) offers an opportunity to incorporate patient-specific values and preferences where evidence is lacking for prosthesis design decisions. To develop resources to facilitate SDM, and consistent with the International Patient Decision Aid Standards, it is necessary to identify the decisional needs of prosthetists and prosthesis users for prosthesis design decisions. OBJECTIVES: To assess the needs of prosthetists and new prosthesis users for SDM about the first prosthesis design. STUDY DESIGN: Qualitative descriptive design. METHODS: Six focus groups were conducted with 38 prosthetists. Individual semistructured interviews were conducted with 17 new prosthesis users. Transcripts were analyzed using directed content analysis, with codes defined a priori using existing frameworks for SDM: the Three Talk Model for SDM and the Ottawa Decision Support Framework. RESULTS: Four main themes were identified among prosthetists and prosthesis users: acknowledging complexity in communication, clarifying values, recognizing the role of experience to inform preferences , and understanding the prosthetic journey . CONCLUSIONS: Resources that support SDM for the first prosthesis design should consider methods for identifying individual communication needs, support with clarifying values, and resources such as experience for achieving informed preferences, within the context of the overall course of rehabilitation and recovery following lower-limb amputation. The themes identified in this work can inform SDM to promote collaborative discussion between prosthetists and new prosthesis users when making prosthesis design decisions.

"This is not negotiable. You need to do this ": A directed content analysis of decision making in rehabilitation after knee arthroplasty.

PURPOSE: To understand patients' and physical therapists' perspectives related to decision making during outpatient rehabilitation after total knee arthroplasty (TKA), and to describe potential barriers and opportunities for shared decision making (SDM) in this setting. METHODS: A qualitative study examined the beliefs, thoughts, and experiences of patients and physical therapists regarding decision making in outpatient rehabilitation after TKA. Semi-structured interviews were conducted and analysed using directed content analysis. RESULTS: Thirty-five participants were interviewed (20 patients, 15 physical therapists). Three main themes emerged from the data: (1) there is variability among physical therapists in how patients are involved in care decisions, (2) several features of the outpatient care paradigm are not supportive of SDM, and (3) preoperative patient-clinician interactions may facilitate SDM in postoperative rehabilitation, but these interactions are not typically utilized. CONCLUSION: Physical therapists described using decision-making strategies with varying levels of patient involvement. Both patients and physical therapists described barriers to routine use of SDM in the outpatient setting. Several actionable strategies for overcoming these barriers were identified for providers and organizations seeking to consistently use SDM in outpatient TKA rehabilitation.

Development of a reference chart for monitoring cancer-related fatigue throughout a supervised exercise program.

BACKGROUND: Cancer-related fatigue (CRF) is one of the most reported and functionally limiting symptoms experienced by individuals living with and beyond cancer. Exercise is effective at reducing CRF, though currently it is not possible to predict the magnitude and time course of improvement for an individual participating in an exercise program. OBJECTIVE: To develop a reference chart of CRF improvement for individuals participating in a 3-month cancer-specific exercise program. METHODS: In this retrospective cohort study, CRF was assessed every two weeks (using the FACIT - Fatigue scale, range: 0 - 52 with lower scores indicating greater fatigue) in 173 individuals participating in a 3-month supervised exercise program (741 observations). No cancer types were excluded and individuals were either undergoing chemotherapy and/or radiation, or within 6 months of completing treatment. The reference chart was developed using Generalized Additive Models for Location Scale and Shape. RESULTS: Each participant had an average of four CRF observations. Lower centiles demonstrated greater improvement than higher centiles (11 points over the duration of the program for the 10th and 4 points for the 90th percentiles). LIMITATIONS: The population is biased to individuals self-selecting or being referred to a clinical exercise program. CONCLUSIONS: This reference chart provides a novel method of monitoring CRF improvement during a cancer-specific exercise program. Setting appropriate expectations and informing exercise prescription adaptation are discussed in the context of representative data from three participants. Future research can investigate improvements in clinical outcomes and the remote monitoring of CRF through the implementation of the reference chart.

Impact of Personalized Outcomes Forecasts on Clinical Reasoning of Physical Therapists in Intermittent Claudication: A Vignette Study.

OBJECTIVE: Guidelines recommend supervised exercise therapy and lifestyle counseling by a physical therapist as initial treatment for patients with intermittent claudication. However, guidelines provide only a crude estimate of the outcomes that therapists and patients might expect from treatment. The purpose of this study was to explore the impact of personalized outcomes forecasts (POFs) on the decision-making process of physical therapists and to learn lessons on facilitating the use of forecasts in daily practice. METHODS: A vignette-based, think-aloud interview study design was used. The participants were physical therapists trained in treating patients with intermittent claudication. Vignettes described fictitious patients diagnosed with intermittent claudication and included POFs. A directed approach was used to code, organize, and describe the data. Transcripts were analyzed using a thematic approach. RESULTS: Sixteen therapists participated in the study. Three themes were identified: (1) setting and contextualizing treatment expectations, (2) setting (shared) goals and (de)motivating the patient, and (3) establishing and monitoring the treatment plan. Therapists mentioned that POFs could be useful for setting expectations and realistic treatment goals, contextualizing expected treatment response, stimulating patients to achieve their goals, and deciding on treatment frequency and treatment timing. Therapists thought POFs would be of less use for changing treatment goals during follow-up visits or for establishing intensity or type of training. CONCLUSION: To overcome challenges that may arise when adopting POFs in daily practice, adequate training of physical therapists should be conducted. Potential areas to address with training include statistical and data literacy as well as guidance on integrating POFs with existing treatment protocols. IMPACT: The use of POFs by physical therapists might contribute to a more person-centered care approach. The insights provided by this study on the first use of POFs by physical therapists can serve as an example and lesson on how to optimally implement such supporting tools into daily practice.

Psychometric Assessment of the Connor-Davidson Resilience Scale for People With Lower-Limb Amputation.

OBJECTIVE: The purpose of this study was to (1) determine the psychometric properties of the 25- and 10-item Connor-Davidson Resilience Scales (CD-RISC25, CD-RISC10) for people with lower-limb amputation (LLA) in middle age or later, and (2) describe relationships of the CD-RISC with biopsychosocial, sociodemographic, and health variables. METHODS: Participants were included if their most recent LLA was 1 or more years prior, if they were independently walking with a prosthesis, and if they were between 45 and 88 years of age (N = 122; mean = 62.5 years of age [SD = 8]; 59.5 [mean = 58] months since LLA; 88.5% male; 82.0% with dysvascular etiology; 68.0% with unilateral transtibial LLA). Psychometric analyses included assessment of skewness, floor and ceiling effects, internal consistency, and agreement between versions. Correlation analyses were used to determine associations between the CD-RISC with disability, perceived functional capacity, falls efficacy, life-space, anxiety, depression, self-efficacy, social support, sociodemographic, and health variables. Additionally, quartiles of participants were identified using CD-RISC25 and CD-RISC10 scores and compared using ANOVA and post-hoc comparisons for disability, perceived functional capacity, falls efficacy, and life-space. RESULTS: Skewness, floor, and ceiling effects of both CD-RISC versions were acceptable. Both versions of the CD-RISC were internally consistent (CD-RISC25: α = .92; CD-RISC10: α = .89). The CD-RISC25 and CD-RISC10 were highly correlated with disability, perceived functional capacity, falls efficacy, anxiety, depression, and self-efficacy (r = 0.52-0.67). CD-RISC25 and CD-RISC10 quartile differences, especially the lowest quartile, were identified for disability, perceived functional capacity, falls efficacy, and life-space. CONCLUSION: The CD-RISC25 and CD-RISC10 have acceptable psychometric properties for use with people who have LLA. CD-RISC scores are associated with clinically relevant biopsychosocial measures targeted by physical therapist intervention following LLA. IMPACT: The CD-RISC may be an appropriate tool to measure resilience following LLA.

Development of a physical mobility prediction model to guide prosthetic rehabilitation.

BACKGROUND: Prosthetic rehabilitation decisions depend on estimating a patient's mobility potential. However, no validated prediction models of mobility outcomes exist for people with lower-limb amputation (LLA). OBJECTIVES: To develop and test predictions for self-reported mobility after LLA, using the Prosthetic Limb Users Survey of Mobility (PLUS-M). STUDY DESIGN: This is a retrospective cohort analysis. METHODS: Eight hundred thirty-one patient records (1,860 PLUS-M observations) were used to develop and test a neighbors-based prediction model, using previous patient data to predict the 6-month PLUS-M T-score trajectory for a new patient (based on matching characteristics). The prediction model was developed in a training data set (n = 552 patients) and tested in an out-of-sample data set of 279 patients with later visit dates. Prediction performance was assessed using bias, coverage, and precision. Prediction calibration was also assessed. RESULTS: The average prediction bias for the model was 0.01 SDs, average coverage was 0.498 (ideal proportion within the 50% prediction interval = 0.5), and prediction interval was 8.4 PLUS-M T-score points (40% improvement over population-level estimates). Predictions were well calibrated, with the median predicted scores falling within the standard error of the median of observed scores, across all deciles of the data. CONCLUSIONS: This neighbors-based prediction approach allows for accurate estimates of PLUS-M T-score trajectories for people with LLA.

Examination of exclusion criteria in total knee arthroplasty rehabilitation trials: influence on the application of evidence in day-to-day practice.

OBJECTIVE: Total knee arthroplasty (TKA) rehabilitation trials use exclusion criteria, which may limit their generalizability in practice. We investigated whether patients seen in routine practice who meet common exclusion criteria recover differently from TKA compared to research-eligible patients. We hypothesized that research-ineligible patients would demonstrate poorer average postoperative function and slower rate of functional recovery compared to research-eligible patients. METHODS: Patient characteristics and exclusion criteria were extracted and summarized from trials included in the three most recent systematic reviews of TKA rehabilitation. Trial participant characteristics were compared to a clinical dataset of patient outcomes collected in routine TKA rehabilitation. Where possible, individual exclusion criterion from the trials were applied to the clinical dataset to determine "eligible" and "ineligible" groups for research participation. Postoperative functional outcomes including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Timed Up and Go (TUG) were compared between "eligible" and "ineligible" groups using mixed effects models. RESULTS: 2,528 participants from 27 trials were compared to 474 patients from the clinical dataset. Research participants were older, with lower Body Mass Index than patients in the clinical dataset. Many patients in the clinical dataset would be "ineligible" for research participation based upon common exclusion criteria from the trials. Differences were observed in average postoperative functioning between some "eligible" and "ineligible" groups in the clinical dataset. However, no differences were observed in functional recovery rate between groups, except for patients with diabetes whose TUG recovered more slowly than their "eligible" counterparts. CONCLUSIONS: Many patients in the clinical dataset were "ineligible" for research participation based upon common TKA rehabilitation trial exclusion criteria. However, the postoperative recovery rate did not differ between "eligible" and "ineligible" groups based on individual exclusion criterion-except for individuals with diabetes. This suggests that both clinical and research populations may recover similarly from TKA.

Reliability, responsiveness, and validity of handheld dynamometry for assessing quadriceps strength in total knee arthroplasty.

PURPOSE: To determine the reliability, responsiveness, validity, and agreement of handheld dynamometry, relative to electromechanical dynamometry, for assessing quadriceps strength surrounding total knee arthroplasty. METHODS: Fifty-six patients (48% female) undergoing total knee arthroplasty were assessed prior to surgery and at 2 and 6 weeks following surgery. Maximum isometric quadriceps force was assessed at each time point by handheld dynamometry and electromechanical dynamometry. Within-session test-retest reliability was determined by intraclass correlation coefficient (ICC). Standard error of measurement and relative standard error (RSE) values were calculated. Standardized response means were used to describe responsiveness. Pearson's correlations examined construct validity. Agreement was assessed by the Bland-Altman method. RESULTS: Both handheld dynamometry and electromechanical dynamometry demonstrated excellent test-retest reliability (ICC >0.90) and RSE (<15%). Both methods were responsive, with large postoperative standardized response means of 1.57 (handheld dynamometry) and 1.37 (electromechanical dynamometry). Pearson's correlations were moderate to strong. The Bland-Altman analysis revealed underestimation of force by handheld dynamometry, although this effect was diminished in the early postoperative period. CONCLUSIONS: Our results suggest handheld dynamometry is a promising tool for monitoring quadriceps strength in patients pre- and post-total knee arthroplasty.IMPLICATIONS FOR REHABILITATIONThis study provides evidence of high reliability and responsiveness of handheld dynamometry for assessing quadriceps strength throughout a clinically relevant time frame for patients with total knee arthroplasty.There is construct validity of handheld dynamometry for measuring quadriceps strength, with moderate to high correlations between handheld dynamometry and electromechanical dynamometry, both pre- and post-total knee arthroplasty.Rehabilitation professionals should be aware that handheld dynamometry and electromechanical dynamometry do not agree in terms of the force measurement itself; particularly at higher force values, handheld dynamometry underestimates force output relative to electromechanical dynamometry.Overall, this study supports the use of handheld dynamometry for monitoring quadriceps strength in clinical settings for patient with total knee arthroplasty.

Neighbors-based prediction of physical function after total knee arthroplasty.

The purpose of this study was to develop and test personalized predictions for functional recovery after Total Knee Arthroplasty (TKA) surgery, using a novel neighbors-based prediction approach. We used data from 397 patients with TKA to develop the prediction methodology and then tested the predictions in a temporally distinct sample of 202 patients. The Timed Up and Go (TUG) Test was used to assess physical function. Neighbors-based predictions were generated by estimating an index patient's prognosis from the observed recovery data of previous similar patients (a.k.a., the index patient's "matches"). Matches were determined by an adaptation of predictive mean matching. Matching characteristics included preoperative TUG time, age, sex and Body Mass Index. The optimal number of matches was determined to be m = 35, based on low bias (- 0.005 standard deviations), accurate coverage (50% of the realized observations within the 50% prediction interval), and acceptable precision (the average width of the 50% prediction interval was 2.33 s). Predictions were well-calibrated in out-of-sample testing. These predictions have the potential to inform care decisions both prior to and following TKA surgery.

Development of a reference chart to monitor postoperative swelling following total knee arthroplasty.

Title: Development of a reference chart to monitor postoperative swelling following total knee arthroplasty.Purpose: Lower extremity swelling is a feature of total knee arthroplasty. Until recently, clinicians lacked tools to accurately measure swelling in clinical settings, but bioelectrical impedance assessment has shown promise in this regard. The purpose of this study was to develop a reference chart of lower extremity swelling following total knee arthroplasty.Method: Fifty-six participants (54% male, mean age = 64 years) were followed for the first 7 weeks following total knee arthroplasty, during which frequent lower extremity bioelectrical impedance assessments were performed. Using Generalized Additive Models for Location Scale and Shape, a reference chart for swelling was developed with bioelectrical impedance assessment data from the first 40 patients enrolled in the study (223 observations) and preliminarily tested for performance in the remaining 16 patients' data (96 observations).Results: The reference chart illustrates approximately 10% per day increase for the first 3 days following surgery. Peak swelling occurs 6-8 days following surgery; the 10th percentile demonstrates a peak of 25%, whereas the 90th percentile peaks at 47%. In the test data, this reference chart demonstrated accurate coverage at each estimated centile.Conclusion: The reference chart provides a novel framework for monitoring swelling following total knee arthroplasty and may augment clinical decisions to improve postoperative swelling management.Implications for rehabilitationThe use of bioelectrical impedance assessment provides an accurate and easily implemented approach for rehabilitation professionals to measure swelling.The reference chart provided allows for monitoring of patient recovery of swelling following total knee arthroplasty.Precise depictions of where a patient's swelling is in reference to others will improve clinical decision making at the individual level.