Should we separately measure the pain parameter of the Constant-Murley score in patients with chronic shoulder pain?

BACKGROUND: The Constant-Murley Score (CMS) is a relatively unique shoulder assessment tool because it combines patient-reported outcomes (pain and activity), performance measurement and clinician-reported outcomes (strength and mobility). With these characteristics, the effect of patient-related psychological factors on the CMS remains debated. We aimed to investigate which parameters of the CMS are influenced by psychological factors by assessing the CMS before and after rehabilitation for chronic shoulder pain. METHODS: This retrospective study screened all patients (18-65 years old) who were admitted for interdisciplinary rehabilitation for chronic shoulder pain (≥ 3 months) between May 2012 and December 2017. Patients with unilateral shoulder injuries were eligible. Exclusion criteria were shoulder instability, concomitant neurological injuries, complex regional pain syndrome (including Steinbrocker syndrome), heavy psychiatric issues, and missing data. The Hospital Anxiety and Depression Scale, Pain Catastrophizing scale, and Tampa Scale of Kinesiophobia were administered before and after treatment. Regression models were used to estimate associations between psychological factors and the CMS. RESULTS: We included 433 patients (88% male, mean age 47±11 years) with a median duration of symptoms of 392.2 days (interquartile range: 266.5-583.5). Rotator cuff issue was present in 71% of patients. During interdisciplinary rehabilitation, patients were followed for a mean of 33.6±7.5 days. The mean CMS at entry was 42.8 ±15.5. The mean gain in CMS after treatment was 10.6 ±10.9. Before treatment, psychological factors were significantly associated with only the pain CMS parameter: -0.37 (95% CI: -0.46 to -0.28), p <0.001. After treatment, psychological factors were associated with the evolution of the four CMS parameters: -0.12 (-0.23 to -0.01) to -0.26 (95% CI: -0.36 to -0.16), p<0.05. CONCLUSIONS: This study raises the question of a distinct assessment of pain when assessing shoulder function with CMS in patients with chronic shoulder pain. The separation of the "pain parameter" from the overall CMS score seems illusory with this tool that is used worldwide. However, clinicians should be aware that psychological factors can negatively influence the evolution of all CMS parameters during follow-up, which argues for a biopsychosocial approach to patients with chronic shoulder pain.

The self-assessment INTERMED predicts healthcare and social costs of orthopaedic trauma patients with persistent impairments.

OBJECTIVE: To use the self-assessment INTERMED questionnaire to determine the relationship between biopsychosocial complexity and healthcare and social costs of patients after orthopaedic trauma. DESIGN: Secondary prospective analysis based on the validation study cohort of the self-assessment INTERMED questionnaire. SETTING: Inpatients orthopaedic rehabilitation with vocational aspects. SUBJECTS: In total, 136 patients with chronic pain and impairments were included in this study: mean (SD) age, 42.6 (10.7) years; 116 men, with moderate pain intensity (51/100); suffering from upper (n = 55), lower-limb (n = 51) or spine (n = 30) pain after orthopaedic trauma; with minor or moderate injury severity (severe injury for 25). MAIN MEASURES: Biopsychosocial complexity, assessed with the self-assessment INTERMED questionnaire, and other confounding variables collected prospectively during rehabilitation. Outcome measures (healthcare costs, loss of wage costs and time for fitness-to-work) were collected through insurance files after case settlements. Linear multiple regression models adjusted for age, gender, pain, trauma severity, education and employment contract were performed to measure the influence of biopsychosocial complexity on the three outcome variables. RESULTS: High-cost patients were older (+3.6 years) and more anxious (9.0 vs 7.3 points at HADS-A), came later to rehabilitation (+105 days), and showed higher biopsychosocial complexity (+3.2 points). After adjustment, biopsychosocial complexity was significantly associated with healthcare (ß = 0.02; P = 0.003; expß = 1.02) and social costs (ß = 0.03; P = 0.006, expß = 1.03) and duration before fitness-to-work (ß = 0.04; P < 0.001, expß = 1.04). CONCLUSION: Biopsychosocial complexity assessed with the self-assessment INTERMED questionnaire is associated with higher healthcare and social costs.

Determination of Perceived Levels of Physical Work Demand Thresholds, and Reliability and Responsiveness of the Modified-Spinal Function Sort Questionnaire in a Multidisciplinary Occupational Rehabilitation Setting.

PURPOSE: To determine the levels of perceived work demand capacity corresponding to the Modified Spinal Function Sort (M-SFS) score and precise reliability validity and responsiveness. METHODS: This prospective validation study included patients with chronic musculoskeletal impairments who underwent multidisciplinary occupational rehabilitation. After determining the percentiles of the work demand thresholds corresponding to the spinal function sort (SFS), the percentiles were transposed to the M-SFS. Reliability was assessed using the intraclass correlation coefficient and limits of agreement. Correlations with other questionnaires and a lifting task were measured to assess validity. Responsiveness was determined using anchor- and distribution-based approaches. RESULTS: 288 patients were included. The following thresholds were obtained for the M-SFS: 0-43 points, minimal; 44-50, very light; 51-58, light; 59-64, light to medium; 65-70, medium; 71-76, heavy; and 77-80, very heavy. Reliability was confirmed. The correlation between the M-SFS and SFS scores was good at 0.89 (95% CI, 0.86-0.91) and moderate according to the PILE-test result of 0.60 (95% CI, 0.50-0.67). We could not calculate a valid anchor-based minimal clinically important difference. The standard error of measurement was 3.9 points, and the smallest detectable change was 10.8 points. CONCLUSIONS: On the basis of the comparison of the M-SFS and SFS scores, the M-SFS score can be interpreted in relation to the levels of work demand. This study confirms the good reliability and validity of the M-SFS questionnaire in assessing perceived physical capacity. Further studies are needed to determine its responsiveness.

"Minimal clinically important difference" estimates of 6 commonly-used performance tests in patients with chronic musculoskeletal pain completing a work-related multidisciplinary rehabilitation program.

BACKGROUND: Functional tests are widely used to measure performance in patients with chronic musculoskeletal pain. Our objective was to determine the Minimal Clinically Important Differences (MCID) for the 6-min walk test (6MWT), the Steep Ramp Test (SRT), the 1-min stair climbing test (1MSCT), the sit-to-stand test (STS), the Jamar dynamometer test (JAM) and the lumbar Progressive Isoinertial Lifting Evaluation (PILE) in chronic musculoskeletal pain patients. METHODS: A single-center prospective observational study was conducted in a rehabilitation center. Patients with upper-limb, lower-limb or neck/back lesions were included over a period of 21 months. We used the anchor-based method as a reference method, supplemented by the distribution-based and opinion-based approaches, to determine the MCIDs. RESULTS: 838 chronic musculoskeletal pain patients were included. The estimation method and thelesion location had a significant influence on the results. MCIDs were estimated at +75m and +60m for the 6MWT (lower-limb and neck/back lesions, respectively), +18 steps for the 1MSCT (lower-limb and neck/back lesions) and +6kg for the JAM (upper limb lesions). The anchor-based method could not provide valid estimations for the three other scales, but distribution and opinion-based methods provided rough values of MCIDs for the SRT (+39w to +61w), the STS (-5 sec to -7 sec) and the PILE (+4kg to +7kg). CONCLUSION: The above MCID estimations for the 6MWT, 1MSCT and JAM can be used in chronic musculoskeletal pain patients participating in vocational multidisciplinary rehabilitation programs or in therapeutic trials. The use of specific anchors might give better estimations of MCIDs for the three other scales in future research.

Influencing walking behavior can increase the physical activity of patients with chronic pain hospitalized for multidisciplinary rehabilitation: an observational study.

BACKGROUND: Physical therapy and exercising are key components of biopsychosocial rehabilitation for chronic pain. Exercise helps reduce pain and improve physical functions. In addition, a high level of physical activity benefits quality of life and emotional well-being. However, the degree to which hospitalization for extensive rehabilitation effectively increases physical activity has not yet been studied. Therefore, we investigated the physical activity level and the walking behavior of inpatients with musculoskeletal pain. The objectives were 1) to compare physical activity level and walking with or without rehabilitation, 2) to evaluate whether pain site influences physical activity level, and 3) to measure the association between physical activity and pain-related interference with physical functioning. METHODS: During a rehabilitation stay, 272 inpatients with lower limb, spine, or upper limb pain wore an accelerometer over 1 week. We assessed the daily duration of the practice of moderate physical activity and walking. Weekend days, during which the participants went home (days off), were used as a reference for habitual activities. We also evaluated 93 patients before the hospitalization to validate the use of days off as a baseline. Pain interference was measured with the brief pain inventory questionnaire. Generalized linear mixed models analyzed the association between physical activity and walking levels, and 1) rehabilitation participation, 2) pain sites, and 3) pain interference. RESULTS: Weekend days during the stay have similar physical activity level as days measured before the stay (73 min / day at the clinic, versus 70 min / day at home). Rehabilitation days had significantly higher physical activity levels and walking durations than days off (+ 28 min [+ 37%] and + 32 min [+ 74%], respectively). Mixed models revealed 1) a negative association between physical activity and pain interference, and 2) no effect of pain sites. Overall, patients increased their physical activity level independently of reported pain interference. CONCLUSIONS: Despite their painful condition, the inpatients were able to engage themselves in a higher level of physical activity via increased participation in walking activities. We conclude that walking incentives can be a valid solution to help patients with chronic pain be more physically active.

Immediate and short-term effects of kinesiotaping on muscular activity, mobility, strength and pain after rotator cuff surgery: a crossover clinical trial.

BACKGROUND: Kinesiotape (KT) is widely used in musculoskeletal rehabilitation as an adjuvant to treatment, but minimal evidence supports its use. The aim of this study is to determine the immediate and short-term effects of shoulder KT on muscular activity, mobility, strength and pain after rotator cuff surgery. METHODS: Thirty-nine subjects who underwent shoulder rotator cuff surgery were tested 6 and 12 weeks post-surgery, without tape, with KT and with a sham tape (ST). KT and ST were applied in a randomized order. For each condition, the muscular activity of the upper trapezius, three parts of the deltoid and the infraspinatus were measured during shoulder flexion, and range of motion (ROM) and pain intensity were assessed. At 12 weeks, the isometric strength at 90° of shoulder flexion, related muscular activity and pain intensity were also measured. Subjects maintained the last tape that was applied for three days and recorded the pain intensity at waking up and during the day. RESULTS: Modifications in muscle activity were observed with KT and with ST. Major changes in terms of decreased recruitment of the upper trapezius were observed with KT (P < 0.001). KT and ST also increased flexion ROM at 6 weeks (P = 0.004), but the differences with the no tape condition were insufficient to be clinically important. No other differences between conditions were found. CONCLUSIONS: Shoulder taping has the potential to decrease over-activity of the upper trapezius, but no clinical benefits of KT on ROM, strength or pain were noted in a population of subjects who underwent rotator cuff surgery. TRIAL REGISTRATION: The study was retrospectively registered on ClinicalTrials.gov PRS ( NCT03379636 ) on 21st December 2017.

Predictive Value of the Fear-Avoidance Model on Functional Capacity Evaluation.

Purpose Measuring the predictive value of the Fear-Avoidance Model (FAM) on lifting tasks in Functional Capacity Evaluation (FCE), and on reasons for stopping the evaluation (safe maximal effort, versus self-limited). Methods A monocentric prospective study was conducted on 298 consecutive inpatients. Components of the FAM were analyzed using the Cumulative Psychosocial Factor Index (CPFI: kinesiophobia, catastrophizing, depressive mood) and perceived disability (Hand/Spinal Function Sort: HFS/SFS). Floor-to-waist, waist-to-overhead and dominant-hand lifting tests were measured according to the FCE guidelines. Maximal safe performance was judged by certified FCE assessors. Analyses were conducted with linear multiple regression models. Results The CPFI was significantly associated with the 3 FCE lifting tests: floor-to-waist (ß = - 1.12; p = 0.039), waist-to-overhead (ß = - 0.88; p = 0.011), and dominant-handed lifting (ß = - 1.21; p = 0.027). Higher perceived disability was also related to lower performances: floor-to-waist (ß = 0.09; p < 0.001), waist-to-overhead (ß = 0.04; p < 0.001), and dominant-handed lifting (ß = 0.06; p < 0.001). The CPFI was not related to performances of patients with self-limited effort despite higher psychological scores, while a relationship was found for patients who achieved a safe maximal performance. Higher perceived disability was related to performances in both situations. Conclusions FAM components should be taken into account when interpreting maximal physical performance in FCE. This study also suggests that factors other than pain-related fears may influence patients with self-limited effort.

A Return-to-Work Prognostic Model for Orthopaedic Trauma Patients (WORRK) Updated for Use at 3, 12 and 24 Months.

Purpose Updating the Wallis Occupational Rehabilitation Risk (WORRK) model formula, predicting non-return to work (nRTW) at different time points (3 and 12 months) than in the validation study (2 years). Methods Secondary analysis of two samples was carried out (following orthopaedic trauma), including work status, the first at 3 months (428 patients) and the second at 12 months (431 patients) after discharge from rehabilitation. We used calibration (agreement between predicted probabilities and observed frequencies) and discrimination (area under the receiver operating characteristics curve) to assess performance of the model after fitting it in the new sample, then calculated the probabilities of nRTW based on the coefficients from the 2-year prediction. Finally, the intercepts were updated for both 3- and 12-month prediction models (re-calibration was necessary for the adjustment of these probabilities) and performance re-evaluated. Results Patient characteristics were similar in all samples (mean age 43 in both groups; 86% male at 3 months, 84% male at 12 months). The proportion of nRTW at 3 months was 63.8% and 53.4% at 12 months (50.36% at 2 years). Performance of the original WORRK for both 3- and 12-month prediction showed an AUC of 0.73, while statistically significant miscalibration was found for both time points (p < 0.001). After the updating of the intercept, calibration was improved and did not show significant miscalibration (p = 0.458 and 0.341). The AUC stayed at 0.73. Conclusion The WORRK model was successfully adapted by changing the intercept for 3- and 12-month prediction of nRTW, now available for use in clinical practice.

Optimal slopes and speeds in uphill ski mountaineering: a laboratory study.

PURPOSE: The purpose of this study was to estimate the energy cost of linear (EC) and vertical displacement (ECvert), mechanical efficiency and main stride parameters during simulated ski mountaineering at different speeds and gradients, to identify an optimal speed and gradient that maximizes performance. METHODS: 12 subjects roller skied on a treadmill at three different inclines (10, 17 and 24 %) at three different speeds (approximately 70, 80 and 85 % of estimated peak heart rate). Energy expenditure was calculated by indirect calorimetry, while biomechanical parameters were measured with an inertial sensor-based system. RESULTS: At 10 % there was no significant change with speed in EC, ECvert and mechanical efficiency. At 17 and 24 % the fastest speed was significantly more economical. There was a significant effect of gradient on EC, ECvert and mechanical efficiency. The most economical gradient was the steepest one. There was a significant increase of stride frequency with speed. At steep gradients only, relative thrust phase duration decreased significantly, while stride length increased significantly with speed. There was a significant effect of gradient on stride length (decrease with steepness) and relative thrust phase duration (increase with steepness). CONCLUSION: A combination of a decreased relative thrust phase duration with increased stride length and frequency decreases ECvert. To minimize the energy expenditure to reach the top of a mountain and to optimize performance, ski-mountaineers should choose a steep gradient (~24 %) and, provided they possess sufficient metabolic scope, combine it with a fast speed (~6 km h(-1)).

Optimal slopes and speeds in uphill ski mountaineering: a field study.

PURPOSE: The aim of this study is to describe the effects of speed and gradient during uphill ski mountaineering on energy expenditure, to relate any changes to changes in stride characteristics, and to determine an optimal gradient and speed allowing minimization of energy expenditure. METHODS: 11 subjects were tested on snowy trails using their mountaineering skis (fitted with skins), boots and poles, at three gradients (7, 11 and 33 %) at 80 % of maximum heart rate (HRmax), and at 11 % also at 90 and 100 % of HRmax. Energy expenditure was calculated by indirect calorimetry to derive energy cost of locomotion (EC), vertical energy cost (ECvert) and mechanical efficiency, while stride length, stride frequency, relative and absolute thrust phase duration, and slope gradient were measured with an inertial sensor-based system. RESULTS: At 11 % there was no change with speed in EC, ECvert and mechanical efficiency, while stride length and frequency increased and absolute thrust phase duration decreased. There was an effect of gradient on EC, ECvert and mechanical efficiency, while speed, stride length and stride frequency decreased and absolute and relative thrust phase duration increased. The most economical gradient (lowest ECvert) was the steepest one. CONCLUSION: During ski mountaineering uphill at shallow gradient (11 %), EC, ECvert and mechanical efficiency do not vary with speed, while at steeper gradient (33 %) economy is improved. It follows that to minimize energy expenditure and optimize performance to reach a place located at a higher altitude, an athlete should choose a steep gradient, if he/she is able to maintain a sufficient speed.

Clinician and Patient-reported Outcomes Are Associated With Psychological Factors in Patients With Chronic Shoulder Pain.

BACKGROUND: Validated clinician outcome scores are considered less associated with psychosocial factors than patient-reported outcome measurements (PROMs). This belief may lead to misconceptions if both instruments are related to similar factors. QUESTIONS: We asked: In patients with chronic shoulder pain, what biopsychosocial factors are associated (1) with PROMs, and (2) with clinician-rated outcome measurements? METHODS: All new patients between the ages of 18 and 65 with chronic shoulder pain from a unilateral shoulder injury admitted to a Swiss rehabilitation teaching hospital between May 2012 and January 2015 were screened for potential contributing biopsychosocial factors. During the study period, 314 patients were screened, and after applying prespecified criteria, 158 patients were evaluated. The median symptom duration was 9 months (interquartile range, 5.5-15 months), and 72% of the patients (114 patients) had rotator cuff tears, most of which were work injuries (59%, 93 patients) and were followed for a mean of 31.6 days (SD, 7.5 days). Exclusion criteria were concomitant injuries in another location, major or minor upper limb neuropathy, and inability to understand the validated available versions of PROMs. The PROMs were the DASH, the Brief Pain Inventory, and the Patient Global Impression of Change, before and after treatment (physiotherapy, cognitive therapy and vocational training). The Constant-Murley score was used as a clinician-rated outcome measurement. Statistical models were used to estimate associations between biopsychosocial factors and outcomes. RESULTS: Greater disability on the DASH was associated with psychological factors (Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale combined coefficient, 0.64; 95% CI, 0.25-1.03; p = 0.002) and social factors (language, professional qualification combined coefficient, -6.15; 95% CI, -11.09 to -1.22; p = 0.015). Greater pain on the Brief Pain Inventory was associated with psychological factors (Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale combined coefficient, 0.076; 95% CI, 0.021-0.13; p = 0.006). Poorer impression of change was associated with psychological factors (Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Tampa Scale of Kinesiophobia coefficient, 0.93; 95% CI, 0.87-0.99; p = 0.026) and social factors (education, language, and professional qualification coefficient, 6.67; 95% CI, 2.77-16.10; p < 0.001). Worse clinician-rated outcome was associated only with psychological factors (Hospital Anxiety and Depression Scale (depression only), Pain Catastrophizing Scale, Tampa Scale of Kinesiophobia combined coefficient, -0.35; 95% CI, -0.58 to -0.12; p = 0.003). CONCLUSIONS: Depressive symptoms and catastrophizing appear to be key factors influencing PROMs and clinician-rated outcomes. This study suggests revisiting the Constant-Murley score. LEVEL OF EVIDENCE: Level III, prognostic study.

Copeptin is associated with kidney length, renal function, and prevalence of simple cysts in a population-based study.

Arginine vasopressin (AVP) has a key role in osmoregulation by facilitating water transport in the collecting duct. Recent evidence suggests that AVP may have additional effects on renal function and favor cyst growth in polycystic kidney disease. Whether AVP also affects kidney structure in the general population is unknown. We analyzed the association of copeptin, an established surrogate for AVP, with parameters of renal function and morphology in a multicentric population-based cohort. Participants from families of European ancestry were randomly selected in three Swiss cities. We used linear multilevel regression analysis to explore the association of copeptin with renal function parameters as well as kidney length and the presence of simple renal cysts assessed by ultrasound examination. Copeptin levels were log-transformed. The 529 women and 481 men had median copeptin levels of 3.0 and 5.2 pmol/L, respectively (P<0.001). In multivariable analyses, the copeptin level was associated inversely with eGFR (ß=-2.1; 95% confidence interval [95% CI], -3.3 to -0.8; P=0.002) and kidney length (ß=-1.2; 95% CI, -1.9 to -0.4; P=0.003) but positively with 24-hour urinary albumin excretion (ß=0.11; 95% CI, 0.01 to 0.20; P=0.03) and urine osmolality (ß=0.08; 95% CI, 0.05 to 0.10; P<0.001). A positive association was found between the copeptin level and the presence of renal cysts (odds ratio, 1.6; 95% CI, 1.1 to 2.4; P=0.02). These results suggest that AVP has a pleiotropic role in renal function and may favor the development of simple renal cysts.

New anthropometry-based age- and sex-specific reference values for urinary 24-hour creatinine excretion based on the adult Swiss population.

BACKGROUND: Urinary creatinine excretion is used as a marker of completeness of timed urine collections, which are a keystone of several metabolic evaluations in clinical investigations and epidemiological surveys. METHODS: We used data from two independent Swiss cross-sectional population-based studies with standardised 24-hour urinary collection and measured anthropometric variables. Only data from adults of European descent, with estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2 and reported completeness of the urinary collection were retained. A linear regression model was developed to predict centiles of the 24-hour urinary creatinine excretion in 1,137 participants from the Swiss Survey on Salt and validated in 994 participants from the Swiss Kidney Project on Genes in Hypertension. RESULTS: The mean urinary creatinine excretion was 193 ± 41 µmol/kg/24 hours in men and 151 ± 38 µmol/kg/24 hours in women in the Swiss Survey on Salt. The values were inversely correlated with age and body mass index (BMI). CONCLUSIONS: We propose a validated prediction equation for 24-hour urinary creatinine excretion in the general European population, based on readily available variables such as age, sex and BMI, and a few derived normograms to ease its clinical application. This should help healthcare providers to interpret the completeness of a 24-hour urine collection in daily clinical practice and in epidemiological population studies.

Analgesic consumption in a large sample of people in musculoskeletal rehabilitation: A descriptive study.

BACKGROUND: Consumption of opioids is increasing worldwide in people with chronic non-cancer pain, although their effectiveness is debated. OBJECTIVES: The aim of the current study was to evaluate analgesic consumption and its association with different variables (demographic variables, pain, anxiety/depression, catastrophism, and kinesiophobia), in the field of musculoskeletal rehabilitation, where no data are available. METHODS: This was a retrospective study over a period of 8 years on people hospitalised for rehabilitation after injury. Participants were classified into 3 categories: no analgesics (NA), non-opioid analgesics (NOA), and opioid analgesics (OPA). ANOVA or chi-squared tests were used to compare the 3 groups. RESULTS: A total of 4,350 people (84% men; mean [SD] age, 44 [11] years) were included. In total, 20% were taking OPA, 40% NOA and 40% NA. In the OPA group, tramadol was mainly used, and the morphine equivalent median dose was 8.3 mg/day. In the NOA group, paracetamol and ibuprofen were mostly used. Symptoms increased progressively across the 3 groups (NA/NOA/OPA), with increased levels of pain severity/interference, anxiety/depression and catastrophizing, and a higher prevalence of neuropathic pain in the OPA group versus the others. CONCLUSIONS: These results are consistent with those found in groups of people with chronic pain taking larger doses of opioids and following opioid reduction or cessation programs. Opioid prescription did not increase over the 8 years, which was reassuring. These factors are important to emphasise because they can be modified in the rehabilitation setting with interdisciplinary management. REGISTRATION: Our database was registered on Mendeley Data.

Heritability, determinants and reference values of renal length: a family-based population study.

OBJECTIVES: In this population-based study, reference values were generated for renal length, and the heritability and factors associated with kidney length were assessed. METHODS: Anthropometric parameters and renal ultrasound measurements were assessed in randomly selected nuclear families of European ancestry (Switzerland). The adjusted narrow sense heritability of kidney size parameters was estimated by maximum likelihood assuming multivariate normality after power transformation. Gender-specific reference centiles were generated for renal length according to body height in the subset of non-diabetic non-obese participants with normal renal function. RESULTS: We included 374 men and 419 women (mean ± SD, age 47 ± 18 and 48 ± 17 years, BMI 26.2 ± 4 and 24.5 ± 5 kg/m(2), respectively) from 205 families. Renal length was 11.4 ± 0.8 cm in men and 10.7 ± 0.8 cm in women; there was no difference between right and left renal length. Body height, weight and estimated glomerular filtration rate (eGFR) were positively associated with renal length, kidney function negatively, age quadratically, whereas gender and hypertension were not. The adjusted heritability estimates of renal length and volume were 47.3 ± 8.5 % and 45.5 ± 8.8 %, respectively (P < 0.001). CONCLUSION: The significant heritability of renal length and volume highlights the familial aggregation of this trait, independently of age and body size. Population-based references for renal length provide a useful guide for clinicians. KEY POINTS: • Renal length and volume are heritable traits, independent of age and size. • Based on a European population, gender-specific reference values/percentiles are provided for renal length. • Renal length correlates positively with body length and weight. • There was no difference between right and left renal lengths in this study. • This negates general teaching that the left kidney is larger and longer.

Reticulocyte dynamic and hemoglobin variability in hemodialysis patients treated with Darbepoetin alfa and C.E.R.A.: a randomized controlled trial.

BACKGROUND: In a simulation based on a pharmacokinetic model we demonstrated that increasing the erythropoiesis stimulating agents (ESAs) half-life or shortening their administration interval decreases hemoglobin variability. The benefit of reducing the administration interval was however lessened by the variability induced by more frequent dosage adjustments. The purpose of this study was to analyze the reticulocyte and hemoglobin kinetics and variability under different ESAs and administration intervals in a collective of chronic hemodialysis patients. METHODS: The study was designed as an open-label, randomized, four-period cross-over investigation, including 30 patients under chronic hemodialysis at the regional hospital of Locarno (Switzerland) in February 2010 and lasting 2 years. Four subcutaneous treatment strategies (C.E.R.A. every 4 weeks Q4W and every 2 weeks Q2W, Darbepoetin alfa Q4W and Q2W) were compared with each other. The mean square successive difference of hemoglobin, reticulocyte count and ESAs dose was used to quantify variability. We distinguished a short- and a long-term variability based respectively on the weekly and monthly successive difference. RESULTS: No difference was found in the mean values of biological parameters (hemoglobin, reticulocytes, and ferritin) between the 4 strategies. ESAs type did not affect hemoglobin and reticulocyte variability, but C.E.R.A induced a more sustained reticulocytes response over time and increased the risk of hemoglobin overshooting (OR 2.7, p = 0.01). Shortening the administration interval lessened the amplitude of reticulocyte count fluctuations but resulted in more frequent ESAs dose adjustments and in amplified reticulocyte and hemoglobin variability. Q2W administration interval was however more favorable in terms of ESAs dose, allowing a 38% C.E.R.A. dose reduction, and no increase of Darbepoetin alfa. CONCLUSIONS: The reticulocyte dynamic was a more sensitive marker of time instability of the hemoglobin response under ESAs therapy. The ESAs administration interval had a greater impact on hemoglobin variability than the ESAs type. The more protracted reticulocyte response induced by C.E.R.A. could explain both, the observed higher risk of overshoot and the significant increase in efficacy when shortening its administration interval. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01666301.

Prosthetic fitting associated with better survival at 5 years after above-knee amputation due to vascular insufficiency.

BACKGROUND: Individuals requiring non-traumatic Gritti-Stokes amputation or mid-thigh amputation usually have multiple comorbidities that place them at high risk of mortality. OBJECTIVE: To determine survival rate 5 years after Gritti-Stokes and mid-thigh amputation in individuals with vascular insufficiency and to identify the predictors of survival. METHODS: We conducted a retrospective observational study including all individuals with vascular insufficiency who underwent amputation from September 2007 to December 2015 in our University Hospital. The indication for amputation was limb necrosis in 86% of cases, infection in 10%, and complications with the stump (discomfort, neuroma or scar dehiscence) in 4%. Medical records were analysed to determine factors and comorbidities. The date of death was retrieved from the national death registry at a minimum of 5 years after amputation. Cox proportional-hazard regression was used to estimate associations between factors and post-amputation survival with hazard ratios (HR) and 95% confidence intervals (CIs). RESULTS: We included 126 people with vascular insufficiency (83 men), mean age was 70 years [20; 97]; eighty-nine participants (71%) died during the study period. Survival rate was 68% at 1 year, 48% at 3 years and 37% at 5 years. Survival was associated with prosthetic fitting (HR 0.306 [95% CI 0.180; 0.521], p<0.001) and length of stay (HR 0.992 [95% CI 0.987; 0.997], p = 0.003). Conversely, limb necrosis was associated with a lower survival rate (HR 3.801 [95% CI 1.615; 8.949], p = 0.002). In a secondary multivariable analysis, Gritti-Stokes amputation was the only factor positively associated with prosthetic fitting (odds ratio 7.407 [95% CI 2.439; 22.489], p<0.001). CONCLUSIONS: The survival rate at 5 years after Gritti-Stokes and mid-thigh amputation in people with vascular insufficiency was 37%. Prosthetic fitting was independently associated with better survival, and Gritti-Stokes amputation was the only factor positively related to prosthetic fitting.

Development and Validation of Short Forms of the Pain Catastrophizing Scale (F-PCS-5) and Tampa Scale for Kinesiophobia (F-TSK-6) in Musculoskeletal Chronic Pain Patients.

Purpose: Chronic pain is a complex phenomenon. Understanding its multiple dimensions requires the use of a combination of several patient-reported outcome measures (PROMs). However, completing multiple PROMs is time-consuming and can be a burden for patients. The objective of our study was to simultaneously reduce the French versions of the Pain Catastrophizing Scale (PCS) and Tampa Scale for Kinesiophobia (TSK) questionnaires to enable their use in an ambulatory and clinical settings. Patients and Methods: We conducted a clinical study between May 2014 and August 2020 in our rehabilitation center. 1428 chronic musculoskeletal pain patients (CMSP) were included. The originality of our approach is that the reduction method included qualitative as well as quantitative analyses. The study was divided into two parts: 1) reduction of the questionnaires (n=1363) based on internal consistency (item-to-total correlation), principal component analysis (item loadings), Rasch analysis (infit/outfit), floor and ceiling effect (quantitative analyses) and expert judgment of items (qualitative analysis), and 2) validation of the reduced questionnaires (n=65), including test-retest reliability (intraclass correlation coefficient [ICC]), homogeneity (Cronbach α), criterion validity (Pearson correlation [r] with the long-version score), determination of the pathological cutoff and Minimal Clinically Important Difference (MCID). The two full-length questionnaires include 30 items in total. Results: The reduction resulted in a 5-item PCS (score 0-20) and 6-item TSK (score 0-24). Psychometric properties of the reduced questionnaires were all acceptable as compared with other version (α=0.89 and 0.71, ICC=0.75 and 0.60, r=0.86 and 0.70, MCID=2 and 2 for PCS and TSK, respectively) while keeping the structure and coherence of the long versions. Conclusion: The two reduced versions of the PCS and TSK can be used in CMSP patient. As their administration only requires a few minutes, they can be implemented in outpatient consultation as well as in clinical settings.

Simple clinical tools improve ability-to-work predictions for individuals 3-24 months after upper limb injury.

BACKGROUND: Despite numerous previous studies, predicting the ability to work (ATW) after an upper limb injury (ULI) remains difficult for those still not working 3-24 months after their initial injury. OBJECTIVES: We aimed to identify simple prognostic characteristics that were associated with the long-term ATW for individuals who remained unable to work several months after the accident that caused their ULI. METHODS: A single-center prospective observational study in a rehabilitation center in the French-speaking part of Switzerland. We included participants who were 18-60 years old, still unable to work because of persistent pain/disability 3-24 months after an ULI, and who were referred to our rehabilitation center for a 1-month intensive interdisciplinary treatment. Data were collected on personal characteristics, body function/structure variables, activity limitations/participation restrictions, and environmental factors. Participants' evolution during rehabilitation was assessed using functional tests/questionnaires and the 7-level self-reported Patient's Global Impression of Change (PGIC) assessment at discharge. Participant outcomes after 1 year were categorized as either able (ATW>0%) or unable (ATW=0%) to work. The best prognostic characteristics were selected by logistic regression analysis. RESULTS: Among the 317 participants, 202 (64%) had an ATW>0% at 1 year. A grip strength ≥16 kg (Jamar Hand Dynamometer score - affected side) and "(I) do not take pain medicine" were independent predictors. Overall, 96% (26/27) of participants with these 2 characteristics had an ATW>0% at 1 year. The simultaneous absence of these characteristics predicted an unfavorable prognosis in 50% (59/119) of participants. For those who also had a positive PGIC score then 100% (25/25) of participants with these 3 characteristics had an ATW>0%; for those without, only 42% (19/45) had an ATW>0%. CONCLUSIONS: Grip strength (≥16 kg) and not taking pain medicine are favorable prognostic factors for an ATW after an ULI. Their absence is associated with a poor ATW prognosis for half of people with ULI and should alert caregivers to risk of long-term absenteeism ("red flags"). Including data from a PGIC further improves the ATW prediction. We recommend that these 3 criteria be systematically evaluated.

Effect of a four-week isocaloric ketogenic diet on physical performance at very high-altitude: a pilot study.

BACKGROUND: A ketogenic diet (KD) reduces daily carbohydrates (CHOs) ingestion by replacing most calories with fat. KD is of increasing interest among athletes because it may increase their maximal oxygen uptake (VO2max), the principal performance limitation at high-altitudes (1500-3500 m). We examined the tolerance of a 4-week isocaloric KD (ICKD) under simulated hypoxia and the possibility of evaluating ICKD performance benefits with a maximal graded exercise bike test under hypoxia and collected data on the effect of the diet on performance markers and arterial blood gases. METHODS: In a randomised single-blind cross-over model, 6 recreational mountaineers (age 24-44 years) completed a 4-week ICKD followed or preceded by a 4-week usual mixed Western-style diet (UD). Performance parameters (VO2max, lactate threshold [LT], peak power [Ppeak]) and arterial blood gases (PaO2, PaCO2, pH, HCO3-) were measured at baseline under two conditions (normoxia and hypoxia) as well as after a 4-week UD and 4-week ICKD under the hypoxic condition. RESULTS: We analysed data for all 6 participants (BMI 19.9-24.6 kg m-2). Mean VO2max in the normoxic condition was 44.6 ml kg-1 min-1. Hypoxia led to decreased performance in all participants. With the ICKD diet, median values for PaO2 decreased by - 14.5% and VO2max by + 7.3% and Ppeak by + 4.7%. CONCLUSION: All participants except one could complete the ICKD. VO2max improved with the ICKD under the hypoxia condition. Therefore, an ICKD is an interesting alternative to CHOs dependency for endurance performance at high-altitudes, including high-altitude training and high-altitude races. Nevertheless, decreased PaO2 with ICKD remains a significant limitation in very-high to extreme altitudes (> 3500 m). Trial registration Clinical trial registration Nr. NCT05603689 (Clinicaltrials.gov). Ethics approval CER-VD, trial Nr. 2020-00427, registered 18.08.2020-prospectively registered.