MR arthrography was superior to conventional MRI for detecting labral tears and acetabular cartilage defects and showed a higher interobserver agreement. For femoral cartilage lesions, both modalities yielded comparable results.

Hindfoot alignment measurements should be performed on hindfoot alignment view radiographs using the medial or lateral calcaneal contour or on long axial view radiographs using the calcaneal axis. Interreader agreement of hindfoot alignment measurements is slightly better on long axial view radiographs than on hindfoot alignment view radiographs.

The treatment of musculoskeletal neoplasms and infection is usually based on an initial diagnostic biopsy.Prior to biopsy, a hypothesis should be formed about the most likely diagnosis and a differential diagnosis. These deliberations should consider whether the lesion is a primary benign or malignant tumour, a metastasis, a haematological problem or an infection.A tactical plan should be developed which evaluates the necessity, the risk, the approach and finally defines the technique of biopsy most likely to achieve a representative result in the clinical case.In developing this technical approach, the pitfalls should be anticipated, i.e. inadequate sampling, difficulty of pathological interpretation and contamination.The tactical approach should be developed in conjunction with a multi-disciplinary team together with appropriate pre-biopsy imaging.Cite this article: EFORT Open Rev 2017;2:51–57. DOI: 10.1302/2058-5241.2.160065

Introduction Wondering if the use of drains allowing retransfusion of shed blood as opposed to closed suction drains or no drains would improve quality of care to patients undergoing simple non-cemented primary total hip replacement (THR) using a direct anterior approach, a three-arm prospective randomized study was conducted. Method One hundred and twenty patients were prospectively randomized to receive no drain, closed suction drains or drains designed for re-transfusion of shed blood. Blood loss, VAS pain scores, thigh swelling, hematoma formation, number of dressings changed and hospital stay were compared and patients followed for 3 months. Results Drains did not have any significance on postoperative haemoglobin and haematocrit levels or homologous blood transfusion rates. Patients receiving homologous blood transfusions had too small drain volumes to benefit from re-transfusion and patients, who get drained fluid re-transfused, were far away from being in need of homologous blood transfusion. Omitting drains resulted in more thigh swelling accompanied with a tendency of slightly more pain during the first postoperative day but without effect on clinical and radiological outcome at 3 months. Earlier dry operation sites resulting in simplified wound care and shorter hospital stay was encountered when no drain was used. Conclusion The possibility to re-transfuse drained blood was not an argument for using drains and, accepting more thigh swelling, we stop to use drains in simple noncemented primary THR using the direct anterior approach.

OBJECTIVE: To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. METHODS: Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0°-10°valgus); (2) abnormal valgus (>10°); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. RESULTS: The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11°valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12°valgus. CONCLU-SION: It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images. KEY POINTS : • Abnormal hindfoot alignment can be identified on coronal non-weight-bearing MR images.• The sustentaculum tangent was the best predictor of an abnormally varus hindfoot.• The medial calcaneal contour was the best predictor of a valgus hindfoot. AbstractObjective To investigate the ability of coronal non-weightbearing MR images to discriminate between normal and abnormal hindfoot alignment. Methods Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weightbearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0°-10°v algus); (2) abnormal valgus (>10°); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment.Results The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11°valgus.The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12°valgus. Conclusion It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images.

Objectives To evaluate reliability of ultrasound for detection and quantification of glenohumeral joint effusion. Methods With institutional review board approval and informed consent ultrasound of 30 consecutive patients before and after MR arthrography of the shoulder was performed. Presence and width of any anechoic collection was noted within various locations (biceps tendon sheath, subscapular recess (neutral position and internal rotation), posterior glenohumeral joint recess (neutral position and external rotation)). Injected fluid (8-12 ml) into the glenohumeral joint served as gold-standard. Widths of anechoic collections were correlated (Spearman rank correlation) with injected fluid. Results Glenohumeral anechoic collection was consistently seen in the posterior glenohumeral joint recess with the arm in external rotation (100%, 30/30), and in the biceps tendon sheath (97%, 29/30). Ultrasound was not sensitive at other locations (7%-17%). Mean width in anterior-posterior direction of anechoic collection in the posterior glenohumeral joint recess was 7 mm (range: 3-18 mm), 2 mm (range: 1-7 mm) in the biceps tendon sheath. Significant correlation (R=0.390, p=0.033) was found between width of anechoic collection and injected fluid in the posterior glenohumeral joint recess. Conclusions Glenohumeral joint effusion can be detected and quantified most reliably in the posterior glenohumeral joint recess with the arm in external rotation.

UNLABELLED Traumatic tendon tear of the rotator cuff occurs frequently and leads to fatty muscle infiltration. With regard to the outcome, fatty infiltration of the rotator cuff muscles constitutes a major negative predictive factor after rotator cuff surgery. In 1989, Goutallier et al established his classification system for assessment of fatty infiltration of the rotator cuff muscles. He used computed tomographic (CT) images in the axial plane. Today, the assessment of rotator cuff muscles on axial CT images has been widely replaced by assessment on parasagittal acquired magnetic resonance images. This change raised 2 important questions. First, there is a controversy whether the Goutallier classification can simply be adopted for magnetic resonance imaging. The second question is whether the muscle assessment in the axial plane is interchangeable with that in the parasagittal plane. We hypothesize that the assessment of fatty muscle infiltration is the same on reformatted parasagittal CT images as on axial CT images METHODS Three independent readers, 2 radiologists and one shoulder surgeon, rated fatty changes of the supraspinatus muscle on CT scans of 91 shoulders. Goutallier grades were assessed on axial and reformatted parasagittal CT images in 2 separate reading sessions. The paired t test was used to find differences between grading results on axial and reformatted parasagittal images. The Pearson correlation coefficient and weighted kappa statistics were used to quantify linear correlation, intrareader, and interreader agreement. RESULTS Mean (SD) Goutallier grading among all readers was 0.80 (1.16) (range, 0-4) on axial images and 0.89 (1.05) (range, 004) on parasagittal reconstructions. We detected a trend toward a slightly higher Goutallier grading on parasagittal reconstructions; however, this result was not significant (P = 0.07). The Pearson correlation coefficient was 0.702 (P < 0.001). Weighted kappa statistics indicated a moderately good to good intrareader (range of weighted kappa, 0.53-0.62) and interreader (weighted kappa, axial images, 0.55; reformatted parasagittal images, 0.65) agreement. CONCLUSION Grading of fatty infiltration of the supraspinatus muscle on parasagittal CT images is comparable with the standard Goutallier grading on axial images and is characterized by a moderately good to good intrareader and interreader agreement. Assessment of parasagittal images is characterized by a slightly higher interreader agreement and may therefore be the preferable modality.

IntroductionTotal hip arthroplasty (THA) is one of the most frequently performed procedures in orthopaedics and weakness of external rotators is often recognized thereafter. However, the etiology of lateral hip pain is multifaceted. For the diagnosis of abductor tendon rupture, magnetic resonance imaging (MRI) is the gold standard. As not every patient can be subjected to MRI, a clinical diagnostic test for easy detection of lesions of the abductor tendon is missing. Here, we present the internal rotation lack sign indicating abductor tendon pathology.MethodsThe patient is placed in lateral position on a stretcher with hips and knees in neutral position. The knee is flexed to 45° and the hip passively abducted and elevated by the investigator. With the foot passively abducted, the patient is then asked to bring his knee in direction to the examination table. This motion is also tested passively. The test is regarded positive, if no internal rotation is possible and/or if this is painful. If groin pain is elicited during either of the exercises, the test is also rated positive.ResultsWe evaluated this test in 20 patients clinically and by magnetic resonance imaging (MRI). All patients demonstrated a positive internal rotation lag sign. Twelve of them lag of internal rotation and evidence of anterior abductor tendon rupture on MRI, 8 with lag of internal rotation and no evidence of abductor tendon rupture.ConclusionThe new clinical diagnostic sign presented here may improve the diagnosis of abductor tendon rupture in the future.Level of Evidence: Diagnostic study, level I.