Orthopädische Biomechanik

Das Buch beschreibt Gedankengänge und Vorgehensweisen der orthopädischen Biomechanik, den Kenntnisstand zu Belastung und Beanspruchung des Haltungs- und Bewegungsapparates sowie die Reaktion der Gewebe auf mechanische Einflüsse exakt, aber mit einem Minimum an mathematischer und physikalischer Argumentation. Es gliedert sich in die Abschnitte I Grundlagen aus der Mechanik II Grundlagen aus der Mathematik III Mechanische Aspekte des Haltungs- und Bewegungsapparates IV Übungsaufgaben mit ausgearbeiteten Lösungen Zahlreiche Abbildungen unterstützen die anschauliche Darstellung. Ein Buch für Orthopäden, Ingenieure, Naturwissenschaftler, Physiotherapeuten und Orthopädietechniker in den Bereichen Forschung und Entwicklung von Orthopädie und Rehabilitation.  <br/

Physical examination tests of the shoulder: a systematic review and meta-analysis of diagnostic test performance

Background: Physical examination tests of the shoulder (PETS) are clinical examination maneuvers designed to aid the assessment of shoulder complaints. Despite more than 180 PETS described in the literature, evidence of their validity and usefulness in diagnosing the shoulder is questioned. Methods: This meta-analysis aims to use diagnostic odds ratio (DOR) to evaluate how much PETS shift overall probability and to rank the test performance of single PETS in order to aid the clinician’s choice of which tests to use. This study adheres to the principles outlined in the Cochrane guidelines and the PRISMA statement. A fixed effect model was used to assess the overall diagnostic validity of PETS by pooling DOR for different PETS with similar biomechanical rationale when possible. Single PETS were assessed and ranked by DOR. Clinical performance was assessed by sensitivity, specificity, accuracy and likelihood ratio. Results: Six thousand nine-hundred abstracts and 202 full-text articles were assessed for eligibility; 20 articles were eligible and data from 11 articles could be included in the meta-analysis. All PETS for SLAP (superior labral anterior posterior) lesions pooled gave a DOR of 1.38 [1.13, 1.69]. The Supraspinatus test for any full thickness rotator cuff tear obtained the highest DOR of 9.24 (sensitivity was 0.74, specificity 0.77). Compression-Rotation test obtained the highest DOR (6.36) among single PETS for SLAP lesions (sensitivity 0.43, specificity 0.89) and Hawkins test obtained the highest DOR (2.86) for impingement syndrome (sensitivity 0.58, specificity 0.67). No single PETS showed superior clinical test performance. Conclusions: The clinical performance of single PETS is limited. However, when the different PETS for SLAP lesions were pooled, we found a statistical significant change in post-test probability indicating an overall statistical validity. We suggest that clinicians choose their PETS among those with the highest pooled DOR and to assess validity to their own specific clinical settings, review the inclusion criteria of the included primary studies. We further propose that future studies on the validity of PETS use randomized research designs rather than the accuracy design relying less on well-established gold standard reference tests and efficient treatment options

Comparison of the SF6D, the EQ5D, and the oswestry disability index in patients with chronic low back pain and degenerative disc disease

Background The need for cost effectiveness analyses in randomized controlled trials that compare treatment options is increasing. The selection of the optimal utility measure is important, and a central question is whether the two most commonly used indexes - the EuroQuol 5D (EQ5D) and the Short Form 6D (SF6D) – can be used interchangeably. The aim of the present study was to compare change scores of the EQ5D and SF6D utility indexes in terms of some important measurement properties. The psychometric properties of the two utility indexes were compared to a disease-specific instrument, the Oswestry Disability Index (ODI), in the setting of a randomized controlled trial for degenerative disc disease. Methods In a randomized controlled multicentre trial, 172 patients who had experienced low back pain for an average of 6 years were randomized to either treatment with an intensive back rehabilitation program or surgery to insert disc prostheses. Patients filled out the ODI, EQ5D, and SF-36 at baseline and two-year follow up. The utility indexes was compared with respect to measurement error, structural validity, criterion validity, responsiveness, and interpretability according to the COSMIN taxonomy. Results At follow up, 113 patients had change score values for all three instruments. The SF6D had better similarity with the disease-specific instrument (ODI) regarding sensitivity, specificity, and responsiveness. Measurement error was lower for the SF6D (0.056) compared to the EQ5D (0.155). The minimal important change score value was 0.031 for SF6D and 0.173 for EQ5D. The minimal detectable change score value at a 95% confidence level were 0.157 for SF6D and 0.429 for EQ5D, and the difference in mean change score values (SD) between them was 0.23 (0.29) and so exceeded the clinical significant change score value for both instruments. Analysis of psychometric properties indicated that the indexes are unidimensional when considered separately, but that they do not exactly measure the same underlying construct. Conclusions This study indicates that the difference in important measurement properties between EQ5D and SF6D is too large to consider them interchangeable. Since the similarity with the “gold standard” (the disease-specific instrument) was quite different, this could indicate that the choice of index should be determined by the diagnosis

Demand, Control and Support at Work Among Sick-Listed Patients with Neck or Back Pain: A Prospective Study

Purpose The main aim of this study was to assess changes in perceived demand, control and support at work of neck and back pain patients over 1 year. We also hypothesised that perceived changes in demand, control and support at work were associated with clinical improvement, reduced fear-avoidance beliefs and successful return to work. Methods Four hundred and five sick-listed patients referred to secondary care with neck or back pain were originally included in an interventional study. Of these, two hundred and twenty-six patients reported perceived psychosocial work factors at both baseline and 1-year follow-up, and they were later included in this prospective study. Changes in demand, control and support dimensions were measured by a total of nine variables. Results At the group level, no significant differences were found among the measured subscales. At the individual level, the regression analyses showed that decreases in fear-avoidance beliefs about work were consistently related to decreases in demand and increases in control, whereas decreases in disability, anxiety and depression were related to increases in support subscales. Conclusions The perception of demand, control and support appear to be stable over 1 year in patients with neck and back pain, despite marked improvement in pain and disability. Disability, anxiety, depression and fear-avoidance beliefs about work were significantly associated with the perception of the work environment, whereas neck and back pain were not. The published version is available at link.springer.co

Clinical Study Arm Crank and Wheelchair Ergometry Produce Similar Peak Oxygen Uptake but Different Work Economy Values in Individuals with Spinal Cord Injury

Objective. To study whether values for peak oxygen uptake (VO 2peak ) and work economy (WE) at a standardized workload are different when tested by arm crank ergometry (ACE) and wheelchair ergometry (WCE). Methods. Twelve paraplegic men with spinal cord injury (SCI) in stable neurological condition participated in this cross-sectional repeated-measures study. We determined VO 2peak and peak power output (PO peak ) values during ACE and WCE in a work-matched protocol. Work economy was tested at a standardized workload of 30 Watts (W) for both ACE and WCE. Results. There were no significant differences in VO 2peak (mL⋅kg −1 ⋅min −1 ) between ACE (27.3 ± 3.2) and WCE (27.4 ± 3.8) trials, and a Bland-Altman plot shows that findings are within 95% level of agreement. WE or oxygen consumption at 30 W (VO 2-30W ) was significantly lower during WCE compared to ACE ( &lt; 0.039). Mean (95% CI) PO peak (W) were 130 (111-138) and 100 (83-110) during ACE and WCE, respectively. Conclusion. The findings in the present study support the use of both ACE and WCE for testing peak oxygen uptake. However, WE differed between the two test modalities, meaning that less total energy is used to perform external work of 30 W during wheelchair exercise when using this WCE (VP100 Handisport ergometer). Clinical Trials Protocol Record is NCT00987155/4.2007.2271

Change in pain, disability and influence of fear-avoidance in a work-focused intervention on neck and back pain: a randomized controlled trial

Background Neck and back pain are among the most common causes of prolonged disability, and development of interventions with effect on pain, disability and return to work is important. Reduction of fear avoidance might be one mechanism behind improvement after interventions. The aim of the present study was to evaluate changes in pain and disability at the 12-month follow-up of patients with neck and back pain treated with a work-focused intervention compared to patients treated with standard interventions, and the influence of improvement fear avoidance beliefs during the interventions on pain, disability and return to work at 12-month follow-up. Methods 413 employed patients with back or neck pain referred to secondary care, and sick-listed between 4 weeks and 12 months, were randomized to a work-focused rehabilitation or control interventions. Follow-up was conducted 4 and 12 months after inclusion. The groups were compared (independent sample t-test) regarding differences in disability scores (Oswestry disability index/neck disability index) and pain (numeric rating scale) from baseline to 12-month follow-up. Changes in fear avoidance beliefs (FABQ) from baseline to 4 month follow-up were calculated, and the association between this change and return to work, pain and disability at 12 months were tested in stepwise multiple logistic regression models. Results Pain and, disability scores decreased to in both the work-focused and control intervention to 12-month follow-up, and there were no significant differences between the groups. FABQ decreased similarly in both groups to 4 month follow-up. The logistic regression model revealed an association between a reduced FABQ work score at 4 months and return to work within one year (adjusted OR 3.60, 95% CI 1.19 to 10.88). Reduced FABQ physical activity score at 4 months was associated with decreased disability after 12 months (adjusted OR (3.65. 95% CI 1.43 to 9.28). Conclusions Short work-focused rehabilitation had the same effect on pain and disability as control interventions. Reduction in FABQ-W score after treatment seems to be an important predictor for return to work in both groups

Protein homeostasis in LGMDR9 (LGMD2I) – The role of ubiquitin‐proteasome and autophagy‐lysosomal system

Aims: Limb-girdle muscular dystrophy R9 (LGMDR9) is an autosomal recessive disorder caused by mutations in the fukutin-related protein gene (FKRP), encoding a glycosyltransferase involved in α-dystroglycan modification. Muscle atrophy, a significant feature of LGMDR9, occurs by a change in the normal balance between protein synthesis and protein degradation. The ubiquitin–proteasome system (UPS) and autophagy–lysosomal system play a key role in protein degradation in skeletal muscle cells, but their involvement in the pathology of LGMDR9 is still largely unknown. We have aimed at clarifying whether proteolysis through the UPS and the autophagy–lysosomal pathway is dysregulated in LGMDR9 patients. Methods: Vastus lateralis biopsies from 8 normal controls and 12 LGMDR9 patients harbouring the c.826C>A/c.826C>A FKRP genotype were assessed for protein markers related to UPS, the autophagy–lysosomal system and endoplasmic reticulum (ER) stress/ unfolded protein response (UPR), followed by ultrastructural analysis by transmission electron microscopy (TEM). Results: Protein levels of E3 ubiquitin ligases Atrogin-1 and MuRF1 showed a pattern similar to normal controls. Elevation of the autophagy markers Atg7, LC3B-II, decreased level of p62 as well as downregulation of the negative autophagy regulator mTORC1, indicated an activation of autophagy in LGMDR9. Mitophagy markers Bnip3 and Parkin were decreased. TEM analysis demonstrated accumulation of autophagosome-like structures in LGMDR9 muscle. There was also an increase in the expression of ER stress/UPR markers PDI, peIF2α and CHOP and a decrease in IRE1α. However, GRP94, Bip and Calnexin remained unchanged. Conclusion: Our findings indicate that autophagy and ER stress are induced in LGMDR9 muscle

Arm Crank and Wheelchair Ergometry Produce Similar Peak Oxygen Uptake but Different Work Economy Values in Individuals with Spinal Cord Injury

Objective. To study whether values for peak oxygen uptake (VO2peak) and work economy (WE) at a standardized workload are different when tested by arm crank ergometry (ACE) and wheelchair ergometry (WCE). Methods. Twelve paraplegic men with spinal cord injury (SCI) in stable neurological condition participated in this cross-sectional repeated-measures study. We determined VO2peak and peak power output (POpeak) values during ACE and WCE in a work-matched protocol. Work economy was tested at a standardized workload of 30 Watts (W) for both ACE and WCE. Results. There were no significant differences in VO2peak (mL·kg−1·min−1) between ACE (27.3 +/- 3.2) and WCE (27.4 +/- 3.8) trials, and a Bland-Altman plot shows that findings are within 95% level of agreement. WE or oxygen consumption at 30 W (VO2-30W) was significantly lower during WCE compared to ACE (P peak (W) were 130 (111–138) and 100 (83–110) during ACE and WCE, respectively. Conclusion. The findings in the present study support the use of both ACE and WCE for testing peak oxygen uptake. However, WE differed between the two test modalities, meaning that less total energy is used to perform external work of 30 W during wheelchair exercise when using this WCE (VP100 Handisport ergometer). Clinical Trials Protocol Record is NCT00987155/4.2007.2271