FGF-2-dependent signaling activated in aged human skeletal muscle promotes intramuscular adipogenesis.

Aged skeletal muscle is markedly affected by fatty muscle infiltration, and strategies to reduce the occurrence of intramuscular adipocytes are urgently needed. Here, we show that fibroblast growth factor-2 (FGF-2) not only stimulates muscle growth but also promotes intramuscular adipogenesis. Using multiple screening assays upstream and downstream of microRNA (miR)-29a signaling, we located the secreted protein and adipogenic inhibitor SPARC to an FGF-2 signaling pathway that is conserved between skeletal muscle cells from mice and humans and that is activated in skeletal muscle of aged mice and humans. FGF-2 induces the miR-29a/SPARC axis through transcriptional activation of FRA-1, which binds and activates an evolutionary conserved AP-1 site element proximal in the miR-29a promoter. Genetic deletions in muscle cells and adeno-associated virus-mediated overexpression of FGF-2 or SPARC in mouse skeletal muscle revealed that this axis regulates differentiation of fibro/adipogenic progenitors in vitro and intramuscular adipose tissue (IMAT) formation in vivo. Skeletal muscle from human donors aged >75 y versus <55 y showed activation of FGF-2-dependent signaling and increased IMAT. Thus, our data highlights a disparate role of FGF-2 in adult skeletal muscle and reveals a pathway to combat fat accumulation in aged human skeletal muscle.

Lateral femoral circumflex artery contribution to the articular and periarticular hip circulation: relevance to the anterior hip approach-a cadaveric study.

BACKGROUND: The purpose of this cadaveric study was to anatomically demonstrate the contribution of the lateral femoral circumflex artery (LFCA) to the articular and peri-articular hip circulation with an emphasis on the vascularization of hip abductors specially tensor fasciae latae muscle (TFLM). METHODS AND MATERIALS: Thirty hips from 26 fresh cadavers were dissected after injection of the aorta or common iliac artery by colored silicon, to study the contribution of the LFCA to the articular and periarticular hip circulation. Furthermore, the aorta was injected in another 18 fresh cadavers after unilaterally ligating the ascending branch of the LFCA (a-LFCA) as the vascular pedicle of the TFLM, to evaluate the collateral circulation to the TFLM, if available. RESULTS: In all specimens but one, the a-LFCA was found as the single major vascular pedicle of the TFLM. When ligated, only 4 out of 18 hips demonstrated colored cast vessels in the cut surface of the muscle. The ascending branch had also consistent but variable contribution to the gluteus medius and gluteus minimus muscles in 80% of the hips. Furthermore, the a-LFCA consistently supplied the anterior and anterolateral aspects of the hip capsule. In 35% of hips, the a-LFCA contributed to the femoral head and neck circulation via one or two small anterior retinacular arteries. CONCLUSION: LFCA contribution to the articular and periarticular hip circulation is only delivered by the ascending branch. The TFLM is specially perfused by the a-LFCA; its ligation significantly decreases the muscle perfusion. It is poorly supplied by the collateral circulation.

Bernese periacetabular osteotomy (PAO): from its local inception to its worldwide adoption.

The development of the Bernese periacetabular osteotomy (PAO) is based on a structured approach starting with an analysis of the preexisting procedures to improve the coverage of the femoral head and was followed by a list of additional goals and improvements. Cadaveric dissections with a detailed description of the vascular supply of acetabulum and periacetabular bone set the stage for an intrapelvic approach, which offered the largest acetabular correction possible combined with safe intracapsular access. The final composition of osteotomies required the development of several instruments and cutting devices before the feasibility could be tested on a series of cadaveric hips.While the sequence of the osteotomies remained largely unchanged over time (except for the pubic and ischial osteotomies), several propositions for an easier/less invasive approach have been discussed; some made it into standard practice. Efforts were undertaken to optimize the learning curve and minimize failures using video-clips, hands-on courses, fellowships, publications, and ongoing mentoring programs. In retrospect, with almost 40 years of experience, such efforts have promoted a worldwide adoption of the Bernese periacetabular osteotomy.

Is Internal Rotation Measurement of the Hip Useful for Ruling in Cam or Pincer Morphology in Asymptomatic Males? A Diagnostic Accuracy Study.

BACKGROUND: Cam and pincer morphologies are associated with limited internal rotation. However, the routine clinical examination for hip rotation has limited reliability. A more standardized method of measuring hip rotation might increase test-retest and interobserver reliability and might be useful as a screening test to detect different hip morphologies without the need for imaging. We developed an examination chair to standardize the measurement of internal hip rotation, which improved interobserver reliability. However, the diagnostic test accuracy for this test is unknown. QUESTION/PURPOSE: Is a standardized method of determining internal hip rotation using an examination chair useful in detecting cam and pincer morphology with MRI as a reference standard? METHODS: A diagnostic test accuracy study was conducted in a sample of asymptomatic males. Using an examination chair with a standardized seated position, internal rotation was measured in 1080 men aged 18 to 21 years who had been conscripted for the Swiss army. The chair prevents compensatory movement by stabilizing the pelvis and the thighs with belts. The force to produce the internal rotation was standardized with a pulley system. Previous results showed that the measurements with the examination chair are similar to clinical assessment but with higher interobserver agreement. A random sample of 430 asymptomatic males was invited to undergo hip MRI. Of those, 244 White European males responded to the invitation and had a mean age of 20 ± 0.7 years and a mean internal rotation of the hip of 33° ± 8.5°. Using MRI as the reference standard, 69% (169 of 244) had a normal hip, 24% (59 of 244) a definite cam morphology (Grades 2 and 3), 3% (8 of 244) an increased acetabular depth, and 3% (8 of 244) a combination of both. One experienced radiologist graded cam morphology as follows: 0 = normal, 1 = mild, 2 = moderate, and 3 = severe. Pincer morphology was defined by increased acetabular depth (≤ 3 mm distance between the center of the femoral neck and the line connecting the anterior and posterior acetabular rims). The intraobserver agreement was substantial (weighted κ of 0.65). A receiver operating characteristic (ROC) curve was fitted, and sensitivity, specificity, and likelihood ratios were estimated for different internal rotation cutoffs. RESULTS: For cam morphology, the area under the ROC curve was 0.75 (95% CI 0.67 to 0.82). Internal hip rotation of less than 20° yielded a positive likelihood ratio of 9.57 (sensitivity 0.13, specificity 0.99), and a value of 40° or more resulted in a negative likelihood ratio of 0.36 (sensitivity 0.93, specificity 0.20). The area under the curve for detecting the combination of cam and pincer morphologies was 0.87 (95% CI 0.74 to 1.0). A cutoff of 20° yielded a positive likelihood ratio of 9.03 (sensitivity 0.33, specificity 0.96). CONCLUSION: This examination chair showed moderate-to-good diagnostic value to rule in hip cam morphology in White European males. However, at the extremes of the 95% confidence intervals, diagnostic performance would be poor. Nonetheless, we believe this test can contribute to identifying cam morphologies, and we hope that future, larger studies-ideally in more diverse patient populations-will seek to validate this to arrive at more precise estimates of the diagnostic performance of this test. LEVEL OF EVIDENCE: Level III, diagnostic study.

The trochanteric double contour is a valuable landmark for assessing femoral offset underestimation on standard radiographs: a retrospective study.

BACKGROUND: Inaccurate projection on standard pelvic radiographs leads to the underestimation of femoral offset-a critical determinant of postoperative hip function-during total hip arthroplasty (THA) templating. We noted that the posteromedial facet of the greater trochanter and piriformis fossa form a double contour on radiographs, which may be valuable in determining the risk of underestimating femoral offset. We evaluate whether projection errors can be predicted based on the double contour width. METHODS: Plain anteroposterior (AP) pelvic radiographs and magnetic resonance images (MRIs) of 64 adult hips were evaluated retrospectively. Apparent femoral offset, apparent femoral head diameter and double contour widths were evaluated from the radiographs. X-ray projection errors were estimated by comparison to the true neck length measured on MRIs after calibration to the femoral heads. Multivariate analysis with backward elimination was used to detect associations between the double contour width and radiographic projection errors. Femoral offset underestimation below 10% was considered acceptable for templating. RESULTS: The narrowest width of the double line between the femoral neck and piriformis fossa is significantly associated with projection error. When double line widths exceed 5 mm, the risk of projection error greater than 10% is significantly increased compared to narrower double lines, and the acceptability rate for templating drops below 80% (p = 0.02). CONCLUSION: The double contour width is a potential landmark for excluding pelvic AP radiographs unsuitable for THA templating due to inaccurate femoral rotation.

Is There a Scientific Rationale for the Refixation of Delaminated Chondral Flaps in Femoroacetabular Impingement? A Laboratory Study.

BACKGROUND: Debonding of the acetabular cartilage is a characteristic type of hip damage found in cam-type femoroacetabular impingement (FAI), which remains a treatment challenge. In addition to resection, refixation of these flaps using fibrin sealants has been recently suggested. However, there is only limited evidence available that the proposed refixation method results in sufficient viable cartilage formation to ensure long-term flap grafting and restored tissue function. QUESTIONS/PURPOSES: To determine the flap tissue characteristics that would justify refixation of delaminated chondral flaps with a fibrin sealant, we characterized (1) the extracellular matrix (ECM) of chondral flaps in terms of chondrocyte viability and distribution of ECM components and (2) the chondrogenic potential of resident cells to migrate into fibrin and produce a cartilaginous matrix. METHODS: Ten acetabular chondral flaps and three non-delaminated control cartilage samples were resected during surgery. Chondrocyte viability was quantified using a live-dead assay. To assess the ECM, histological staining of glycosaminoglycans, collagen II, and collagen I allowed the qualitative study of their distribution. The ability of chondrocytes to migrate out of the ECM was tested by encapsulating minced flap cartilage in fibrin gels and semi-quantitatively assessing the projected area of the gel covered with migrating cells. The potential of chondrocytes to produce a cartilaginous matrix was studied with a pellet assay, a standard three-dimensional culture system to test chondrogenesis. Positive controls were pellets of knee chondrocytes of age-matched donors, which we found in a previous study to have a good capacity to produce cartilage matrix. Statistical significance of controlled quantitative assays was determined by the Student's t-test with Welch's correction. RESULTS: The proportion of viable chondrocytes in flaps was lower than in nondelaminated cartilage (50% ± 19% versus 76 ± 6%; p = 0.02). Histology showed a disrupted ECM in flaps compared with nondelaminated controls, with the presence of fibrillation, a loss of glycosaminoglycan at the delaminated edge, collagen II throughout the whole thickness of the flap, and some collagen I-positive area in two samples. The resident chondrocytes migrated out of this disrupted ECM in all tested samples. However in pellet culture, cells isolated from the flaps showed a qualitatively lower chondrogenic potential compared with positive controls, with a clearly inhomogeneous cell and matrix distribution and an overall smaller projected area (0.4 versus 0.7 mm; p = 0.038). CONCLUSION: Despite the presence of viable chondrocytes with migration potential, the cells resided in a structurally altered ECM and had limited capacity to deposit ECM, leading us to question their capacity to produce sufficient ECM within the fibrin sealant for stable long-term attachment of such flaps. CLINICAL RELEVANCE: The characterization of delaminated cartilage in cam FAI patients suggests that the refixation strategy might be adversely influenced by the low level of ECM produced by the residing cells.

Patient-reported outcome measures for hip-related pain: a review of the available evidence and a consensus statement from the International Hip-related Pain Research Network, Zurich 2018.

Hip-related pain is a well-recognised complaint among active young and middle-aged active adults. People experiencing hip-related disorders commonly report pain and reduced functional capacity, including difficulties in executing activities of daily living. Patient-reported outcome measures (PROMs) are essential to accurately examine and compare the effects of different treatments on disability in those with hip pain. In November 2018, 38 researchers and clinicians working in the field of hip-related pain met in Zurich, Switzerland for the first International Hip-related Pain Research Network meeting. Prior to the meeting, evidence summaries were developed relating to four prioritised themes. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of PROMs to assess disability in young and middle-aged active adults with hip-related pain. Our process to gain consensus had five steps: (1) systematic review of systematic reviews; (2) preliminary discussion within the working group; (3) update of the more recent high-quality systematic review and examination of the psychometric properties of PROMs according to established guidelines; (4) formulation of the recommendations considering the limitations of the PROMs derived from the examination of their quality; and (5) voting and consensus. Out of 102 articles retrieved, 6 systematic reviews were selected and assessed for quality according to AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). Two showed moderate quality. We then updated the most recent review. The updated literature search resulted in 10 additional studies that were included in the qualitative synthesis. The recommendations based on evidence summary and PROMs limitations were presented at the consensus meeting. The group makes the following recommendations: (1) the Hip and Groin Outcome Score (HAGOS) and the International Hip Outcome Tool (iHOT) instruments (long and reduced versions) are the most appropriate PROMs to use in young and middle-aged active adults with hip-related pain; (2) more research is needed into the utility of the HAGOS and the iHOT instruments in a non-surgical treatment context; and (3) generic quality of life measures such as the EuroQoL-5 Dimension Questionnaire and the Short Form Health Survey-36 may add value for researchers and clinicians in this field. We conclude that as none of the instruments shows acceptable quality across various psychometric properties, more methods studies are needed to further evaluate the validity of these PROMS-the HAGOS and iHOT-as well as the other (currently not recommended) PROMS.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018.

There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

Standardised measurement of physical capacity in young and middle-aged active adults with hip-related pain: recommendations from the first International Hip-related Pain Research Network (IHiPRN) meeting, Zurich, 2018.

Hip-related pain can significantly impact quality of life, function, work capacity, physical activity and family life. Standardised measurement methods of physical capacity of relevance to young and middle-aged active adults with hip-related pain are currently not established. The aim of this consensus paper was to provide recommendations for clinical practice and research on standardised measurement methods of physical capacity in young and middle-aged active adults with hip-related pain. Four areas of importance were identified: (1) clinical measures (range of motion, muscle strength, functional impairments), (2) laboratory-based measures (biomechanics and muscle function (muscle activity, size and adiposity)), (3) physical activity, and (4) return to sport/performance. The literature was reviewed, and a summary circulated to the working group to inform discussion at the consensus meeting. The working group developed clinical and research recommendations from the literature review, which were further discussed and modified within the working group at the consensus meeting. These recommendations were then presented to all 38 International Hip-related Pain Research Network (IHiPRN) participants for further discussion, refinement and consensus voting. Therefore, the recommendations voted on were based on a combination of current evidence and expert opinion. The consensus meeting voted on 13 recommendations, six of which were clinically orientated, and seven more research specific. We recommended that clinicians working with young and middle-aged active adults with hip-related pain assess strength using objective methods of measurement, and clinically assess performance of functional tasks, including walking and running. Physical activity should be quantified using both self-reported and objective measures, and patient expectations of recovery should be quantified prior to treatment. It was recommended that return to physical activity (including sport and occupation) be quantified, and sport-specific activities should be assessed prior to return to sport. The IHiPRN participants were uncertain regarding recommendations for range of motion assessment. Research recommendations were that the measurement properties of range of motion, strength and functional performance tests be investigated, reported and improved in both clinical and research settings. Reporting of movement-related parameters (biomechanics and muscle function) should be standardised and the relationship among movement-related parameters, symptoms, function, quality of life, and intra-articular and imaging findings should be investigated. Quantification of return to physical activity (including sport and occupational demands) is required in future research, and the return to sport continuum should be used. Future research is required to determine the best criteria for rehabilitation progression and return to physical activity following hip-related pain management.

Physiotherapist-led treatment for young to middle-aged active adults with hip-related pain: consensus recommendations from the International Hip-related Pain Research Network, Zurich 2018.

The 1st International Hip-related Pain Research Network meeting discussed four prioritised themes concerning hip-related pain in young to middle-aged adults: (1) diagnosis and classification of hip-related pain; (2) patient-reported outcome measures for hip-related pain; (3) measurement of physical capacity for hip-related pain; (4) physiotherapist-led treatment for hip-related pain. Thirty-eight expert researchers and clinicians working in the field of hip-related pain attended the meeting. This manuscript relates to the theme of physiotherapist-led treatments for hip-related pain. A systematic review on the efficacy of physiotherapist-led interventions for hip-related pain (published separately) was conducted and found that strong evidence for physiotherapist-led treatments was lacking. Prior to the meeting, draft consensus recommendations for consideration in the meeting were also developed based on the systematic review. The draft consensus recommendations were presented to all of the meeting participants via email, at least 1 week prior to the meeting. At the meeting, these recommendations were discussed, revised and voted on. Six recommendations for clinical practice and five recommendations for research were included and all gained consensus. Recommendations for clinical practice were that (i) Exercise-based treatments are recommended for people with hip-related pain. (ii) Exercise-based treatment should be at least 3 months duration. (iii) Physiotherapist-led rehabilitation after hip surgery should be undertaken. (iv) Patient-reported outcome measures, measures of physical impairment and measures of psychosocial factors should be used to monitor response to treatment. (v) Physical activity (that may include sport) is recommended for people with hip-related pain. (vi) Clinicians should discuss patient expectations, use shared-decision making and provide education. Recommendations for research were (i) Reporting of exercise programmes: Exercise descriptors such as load magnitude, number of repetitions and sets, duration of whole programme, duration of contractile element of exercise, duration of one repetition, time under tension, rest between repetitions, range of motion through which the exercise is performed, and rest between exercise sessions should be reported. (ii) Research should investigate the optimal frequency, intensity, time, type, volume and progression of exercise therapy. (iii) Research should examine the effect of patient education in people with hip-related pain. (iv) Research should investigate the effect of other treatments used in people with hip-related pain (for example: manual therapy, medications, injections). (v) Research should examine the impact of comorbidities and social determinants on treatment effectiveness in people with hip-related pain. Clinicians and researchers working with young to middle-aged active adults with hip-related pain may use these consensus recommendations to guide, develop, test and implement individualised, evidence-based physiotherapist-led rehabilitation programmes.

Editorial Commentary: Return to Sport: An Ill-Defined Parameter.

Femoroacetabular impingement syndrome (FAIS) is a common cause of hip pain and dysfunction in athletes, which can impair their ability to perform and compete in sports. Hip arthroscopy has become a popular and successful treatment option for the management of FAIS and the return to sport (RTS) of athletes. The concept of RTS has evolved in the last years. Various different factors need to be considered when evaluating RTS after hip arthroscopy for FAIS, such as (1) the definition of RTS (return to participation, RTS, return to performance), (2) the sport type (high-impact vs low-impact) and sport level (professional vs recreational), and (3) the time to follow-up evaluation. In addition, return to high-impact sports, such as soccer, might not be the best recommendation for some patients undergoing hip arthroscopy for FAIS, as it may accelerate the degeneration of the hip joint. Future research should consider all these aspects of the RTS outcome after hip arthroscopy for FAIS. Valid RTS rates are of utmost importance to provide adequate expectations to patients and to guide decision-making of hip surgeons.

The Association Between Comorbidity and the Risks and Early Benefits of Total Hip Arthroplasty for Hip Osteoarthritis.

BACKGROUND: The changing demographics of our society will lead to an increasing number of patients presenting for orthopedic surgery with increasing comorbidity. We investigated the association between comorbidity and both the risks (complications) and benefits (improved function) of total hip arthroplasty (THA) for primary hip osteoarthritis, whilst controlling for potential confounders including age. METHODS: One thousand five hundred and eighty-four patients (67.1 ± 10.6 years; 54% men) in our tertiary care orthopedic hospital completed the Oxford Hip Score before and 12 months after THA. Comorbidity was assessed using the American Society of Anesthesiologists (ASA) grade and Charlson Comorbidity Index (CCI). Details regarding perioperative complications (hospital stay plus 18 days after discharge; mean 27 ± 3 days) were extracted from the clinic information system and graded for severity. RESULTS: For ASA1, 2, and ≥3, respectively, there were 3.1%, 3.0%, and 6.6% surgical/orthopedic complications; 3.7%, 12.5%, and 27.4% general medical complications; and 6.7%, 14.5%, and 29.8% complications of either type. ASA was associated with complication severity (P < .001). In multiple regression, increasing ASA grade (OR 1.74; 95% CI, 1.33-2.29) and age (OR 1.06; 95% CI, 1.05-1.08), both showed an independent association with increased risk of a complication; CCI explained no further significant variance. CCI, but not age, was associated with the 12-month Oxford Hip Score (beta coefficient, -0.742; 95% CI, -1.130 to -0.355; P = .002) while ASA grade explained no further variance. CONCLUSION: Greater comorbidity was associated with increased odds of a complication and (independently) slightly worse patient-rated outcome 12 months after THA. Comorbidity indices can be easily obtained for all surgical patients and may assist with preoperative counseling regarding individual risks and benefits of THA.

Total hip arthroplasty using the direct anterior approach and intraoperative neurophysiological monitoring for Crowe III hip dysplasia : surgical technique and case series.

Developmental dysplasia of the hip with a high dislocation may lead to severe hip pain and a marked shortening. Nerve palsy rates following THA in dysplastic hips have been reported as being higher by ten times or more compared to the general population. We report a new technique to perform THA in high congenital dislocations. Between 2013 and 2015, 3 consecutive patients (4 hips) with severe hip pain and Crowe III hip dysplasia were treated. Surgeries were performed on a standard table using the DAA and intraoperative neurophysiological monitoring. At final follow-up (mean 24 months, range 15-43), all 3 patients reported excellent pain relief and significant improvement in activities of daily living. Radiographs showed the components to be solidly fixed in satisfactory position. Average postoperative leg lengthening was 24 mm (range 20-36). None of the patients experienced an acute or delayed neurologic deficit. Total hip arthroplasty for high congenital dislocations can be safely performed using the direct anterior approach and neuromonitoring. Significant lengthening could be obtained without neurological complications.

Editorial Commentary: Do Patients With Femoroacetabular Impingement Syndrome Already Show Hip Muscle Atrophy?

Muscle atrophy, fatty degeneration, and strength deficits of the hip abductors, flexors, and even external rotators are well-known clinical and radiologic findings in patients with advanced hip osteoarthritis. More recently, in the context of prearthritic hip diseases, the role of hip muscle function in femoroacetabular impingement syndrome (FAIS) has gained greater focus for hip surgeons. Several studies have shown that patients with FAIS present with activation deficits of the hip muscles, which may result in hip muscle weakness. Nevertheless, previous studies have yet to determine whether young and mainly active patients with FAIS already show hip muscle atrophy. Future research is required to further characterize hip muscle function in patients with FAIS. Of particular interest is the investigation of whether both qualitative (muscle fatty degeneration) and quantitative (muscle atrophy) morphologic alterations of the hip muscles are present in patients with FAIS, as well as whether these alterations are sex specific and/or related to the underlying hip morphology.

MRI Assessment of Supra- and Infratrochanteric Femoral Torsion: Association With Femoroacetabular Impingement and Hip Dysplasia.

OBJECTIVE: The objective of our study was to evaluate a novel measurement technique for assessing the supra- and infratrochanteric components of femoral torsion, establish reference values in healthy volunteers, and compare supra- and infratrochanteric torsion angles in patients with hip dysplasia and patients with femoroacetabular impingement (FAI) with those in healthy volunteers. MATERIALS AND METHODS: Femoral torsion was assessed in 380 patients and 61 healthy volunteers on MRI. For assessing supra- and infratrochanteric torsion, three measurement techniques (i.e., Kim, simplified Kim, and centroid methods) were evaluated by two readers on 100 patients. The technique with the highest interreader reliability was selected to perform measurements on all patients and volunteers. Supra- and infratrochanteric torsion angles of patients were stratified by hip disorders, which were diagnosed by specialized hip surgeons, and were compared with reference values of healthy volunteers. Statistical analysis included the independent t test, Mann-Whitney U test, and intraclass correlation coefficient (ICC). RESULTS: The centroid method showed the highest interreader reliability for measuring supra-and infratrochanteric torsion with an ICC of 0.979. The supra- and infratrochanteric torsion values of the volunteers were 31.5° ± 7.4° (mean ± SD) and -18.3° ± 9.9°, respectively. In comparison with the volunteers, patients with hip dysplasia had significantly higher supraand infratrochanteric torsion values of 37.5° ± 10.3° (p = 0.001) and -9.6° ± 11.7° (p < 0.001) and patients with pincer-type FAI had significantly higher supratrochanteric torsion values of 37.8° ± 8.0° (p = 0.002). CONCLUSION: The supra- and infratrochanteric components of femoral torsion differ substantially between hip disorders: Patients with hip dysplasia have predominantly increased infratrochanteric torsion, whereas patients with pincer-type FAI have increased supratrochanteric torsion. Quantification of separate supra- and infratrochanteric torsion angles allows a more detailed analysis of hip disorders and may influence treatment planning.

EUROSPINE 2017 FULL PAPER AWARD: Time to remove our rose-tinted spectacles: a candid appraisal of the relative success of surgery in over 4500 patients with degenerative disorders of the lumbar spine, hip or knee.

PURPOSE: Studies comparing the outcome of spine surgery with that of large-joint replacement report equivocal findings. The patient-reported outcome measures (PROMs) used in such studies are typically generic and may not be sufficiently sensitive to the successes/failures of treatment. This study compared different indices of "success" in patients undergoing surgery for degenerative disorders of the lumbar spine, hip, or knee, using a validated, multidimensional, and joint-specific PROM. METHODS: Preoperatively and 12 months postoperatively, 4594 patients (3937 lumbar spine, 368 hip, 269 knee) undergoing first-time surgery completed a PROM that included the Core Outcome Measures Index (COMI) for the affected joint. The latter comprises a set of single items on pain, function, symptom-specific well-being, quality of life, and disability-all in relation to the specified joint problem. Other single-item ratings of treatment success were made 12 months postoperatively. RESULTS: In multiple regression analyses, controlling for confounders, the mean improvement in COMI at 12 months was greatest for the hip patients and lowest for those with degenerative spinal deformity (= the statistical reference group) (p < 0.05). Compared with spinal deformity, the odds of achieving "success" were: higher for hip (OR 4.6; 95% CI 2.5-8.5) and knee (OR 4.0; 95% CI 2.1-7.7) (no difference between spine subgroups) for "satisfaction with care"; higher for hip (OR 16.9; 95% CI 7.3-39.6), knee (OR 6.3; 95% CI 3.4-11.6), degenerative spondylolisthesis (OR 1.6; 95% CI 1.2-2.2), and herniated disc (OR 1.7; 95% CI 1.2-2.4) for "global treatment outcome"; and higher for hip (OR 13.8; 95% CI 8.8-21.6), knee (OR 5.3; 95% CI 3.6-7.8), degenerative spondylolisthesis (OR 1.6; 95% CI 1.3-2.1), and herniated disc (1.5; 95% CI 1.1-2.0) for "patient-acceptable symptom state". Patient-rated complications were the greatest in degenerative spinal deformity (29%) and the lowest in hip (18%). CONCLUSIONS: The current study is the largest of its kind and the first to use a common, but joint-specific instrument to report patient-reported outcomes after surgery for degenerative disorders of the spine, hip, or knee. The findings provide a sobering account of the significantly poorer outcomes after spine surgery compared with large-joint replacement. Further work is required to hone the indications and patient selection criteria for spine surgery. The data should be used to lobby research funding-bodies, governmental agencies, industry, and charitable foundations to invest more in spine research/registries, in the hope of ultimately improving spine outcomes. These slides can be retrieved under Electronic Supplementary Material.

The German Lower Extremity Functional Scale (LEFS) is reliable, valid and responsive in patients undergoing hip or knee replacement.

PURPOSE: To determine the measurement properties of a German version of the Lower Extremity Functional Scale (LEFS) in patients with hip or knee osteoarthritis undergoing total joint replacement (TJR). METHODS: This prospective cohort study included 486 consecutive patients. The LEFS and other self-reported outcome measures were administered at different time points and several classical measurement properties were determined. RESULTS: The German LEFS was highly reliable (ICC 0.98) and internally consistent (CA 0.95). Construct validity was proven by large to very large correlations (r = 0.52-0.91) with all other instruments in the expected directions. Factor analysis using a polychoric correlation matrix revealed two factors at baseline and 6 months explaining about 70% of the total variance. There were no floor or ceiling effects for the total score, but significant floor effects for the single items 16-19 at baseline. The LEFS was highly responsive at 6 months. CONCLUSIONS: The German LEFS proved to be a reliable, valid and responsive tool for the self-assessment of patients undergoing total hip or knee replacement. Nevertheless, the questionnaire seems to summarize more than one construct as highlighted by the factor analysis. Further research seems therefore warranted.

Clinical improvement and satisfaction after total joint replacement: a prospective 12-month evaluation on the patients' perspective.

PURPOSE: To determine short-term improvements, satisfaction rates and the patient acceptable symptom state (PASS) after total joint replacement (TJR) for different patient-reported outcome measures (PROMs). METHODS: This prospective cohort study included 426 consecutive patients undergoing total hip (n = 193) or knee arthroplasty (n = 233). The following PROMs were completed before TJR, and at 3, 6 and 12 months after surgery, respectively: WOMAC, Oxford Hip or Knee Score, Lower Extremity Functional Scale, University of California at Los Angeles (UCLA) activity scale and EuroQol-5 dimension (EQ-5D). Satisfaction rates and the PASS thresholds were also assessed. RESULTS: THA patients improved quicker and achieved higher outcome scores than TKA patients. Comorbidities according to the Sangha score were moderately correlated with all PROM values in an inverse direction at all time points (r = -0.27 to -0.47, p < 0.01) in both groups. Satisfaction with the result of surgery improved over time. At 12 months, more than 90 % of the patients were satisfied or very satisfied with the achieved result. The THA group showed a higher proportion of very satisfied patients than the TKA group at all time points. PASS thresholds increased over time for all PROMs except for the UCLA and the EQ-5D in TKA patients. CONCLUSIONS: More than 90 % of the patients will be satisfied 1 year after TJR. THA patients recover faster than TKA patients, i.e., they achieve higher PROM values at earlier follow-up time points. Cutoff values defining a successful result in terms of the PASS could be defined for all PROMs at different time points and can serve as reference for future studies and patient-oriented follow-ups.