Introduction. The highest incidence of recurrent shoulder instability is in young patients, surgical repair can reduce recurrent instability and improve shoulder function. This has led to an increasing rate of stabilisation and use of MRI to identify associated injuries in first time dislocations. MRA has the benefit of distending the joint and is becoming increasingly used. The aim of this study is to establish the sensitivity and specificity of MRA in the investigation of patients with traumatic anterior shoulder dislocations. Methods. A retrospective analysis of patients undergoing both magnetic resonance arthrography and arthroscopy after a traumatic anterior shoulder dislocation between January 2011 and 2014. Images were interpreted by eight musculoskeletal radiologists and arthroscopic findings were obtained from surgical notes and used as a reference. The sensitivity, specificity and positive predictive value for the different injuries were calculated. Results. 60 patients were reviewed; 88% were male, mean age was 28 years (range 18 to 50) and 27% were primary dislocations. The overall sensitivity and specificity of MRA to all associated injuries was 0.9 (CI 0.83–0.95) and 0.94 (CI 0.9–0.96) retrospectively. The lowest sensitivity was seen in osseous Bankart 0.8 (CI 0.44–0.96) and SLAP lesions 0.5 (CI 0.14–0.86). Conclusion. MRA has a high sensitivity when used to identify associated injuries in shoulder dislocation although in 8 patients (13%) arthroscopy identified an additional injury. The overall agreement between MRA and arthroscopic findings was good but identification of GHL and rotator cuff injuries was poor. Level of Evidence. IV. Conflict of Interests. The authors confirm that they have no relevant financial disclosures or conflicts of interest. Ethical approval was not sought as this was a systematic review

It is known that excessive varus alignment of the femoral stem in total hip replacement (THR) creates a sub-optimal biomechanical environment which is associated with increased rates of revision surgery and component wear. Little is known regarding the effect of femoral stem alignment on patient functional outcome. Methods. Retrospective study of primary THR patients at the RNOH. Alignment of the femoral stem component in-situ was measured subjectively by a consultant musculoskeletal radiologist in both coronal and sagittal planes using post-operative anterior-posterior and lateral pelvic radiographs. Each THR was grouped into valgus, minor-valgus, neutral, minor-varus or varus coronal plane alignment and posterior, minor-posterior, neutral, minor-anterior or anterior sagittal plane alignment. Patient reported functional outcome was assessed by Oxford Hip Score (OHS) and WOMAC questionnaires. Data analysed using a linear regression model. Results. 90 THRs were studied in 87 patients (55 Female). Mean age at THR=62 (22-86). Mean follow-up=17 months (11-39 months). Median OHS=16, WOMAC=8. Coronal plane alignment of the femoral stem was not associated with any change in OHS (p>0.05) or WOMAC score (p>0.05). Sagittal plane alignment of the femoral stem was not associated with any change in OHS (p>0.05) or WOMAC score (p>0.05). Conclusion. Although it is known that alignment of the femoral stem on sagittal and coronal planes has a direct effect on survivorship of the prosthesis, our study does not demonstrate any relationship between femoral stem alignment and functional outcome in patients undergoing primary THR

Magnetic resonance imaging (MRI) is a useful diagnostic tool in evaluating meniscus pathology in the knee. Data from available literature suggests sensitivity and specificity rates around 90% when compared to the gold standard findings at knee arthroscopy. We sought to evaluate the sensitivity, specificity and precision rate (positive predictive value) of MRI at diagnosing meniscus tears within our unit. A retrospective audit of a total of 79 MRI reports and arthroscopic findings spanning a one year period was carried out. There were 66 positive MRI reports and 13 negative reports. There were 6 false positives 4 false negatives when compared to arthroscopic findings. The sensitivity of MRI for detecting meniscus tears was 93.7% with 60 out of 64 tears detected. All 4 false negatives also had at least grade III osteoarthritic changes at arthroscopy. Specificity was rather low at 60% with MRI reporting 6 tears (false positives) out of 15 patients who had no tears found at arthroscopy. The positive predictive value (precision rate) of MRI detecting tears was 90.9%. This data shows that MRI in our unit has a comparable high sensitivity to that in various literature making it a useful tool at ruling out disease with a negative result in the clinical setting. A more useful parameter in the clinical setting is its high precision rate when faced with a positive result. However, its specificity is much lower than that in most published data. A total of 6 tears on MRI turned out not to be on arthroscopy meaning patients could have been subjected to an avoidable invasive procedure in the absence of any other indication. This highlights the importance of obtaining reports from experienced musculoskeletal radiologists and the need for surgeons to review MRI images and match them to clinical information prior to subjecting patients to surgery

Summary. 162 patient cohort with serial Metal Artefact Reduction Sequence MRI scans. Patients with normal initial scans can be followed up at 1 year. Those with abnormal scans should be followed up at a shorter interval of 6 months. Introduction. Cross-sectional imaging is a key investigation in the assessment and surveillance of patients with metal-on-metal (MoM) hip arthroplasty. We present our experience of Metal Artefact Reduction Sequence (MARS) MRI scanning in metal on metal hip arthroplasty. We aimed to investigate the natural history and radiological disease progression from Adverse Reactions to Metallic Debris. Methods. A total cohort of 626 patients who had metal on metal arthroplasty underwent MARS MRI scanning with 162 patients having more than one MRI scan. A musculoskeletal radiologist reviewed and reported on all MRI scans. The findings were described as either normal or classified according to Hart et al. We then considered the patient's progression between groups on serial scans and the time intervals between them. Results. 65 patients had a normal first MRI, 38 (54%) remained normal on follow-up scan with a mean scanning interval of 14.6 months. The remaining 27 patients who progressed form normal to either Type 1/2/3 did so over a mean scan interval of 14 months. Of those 56 patients with a Type 1 (thin walled fluid collection) 28.5% of these progressed during interval scanning and 8.9% of Type 1 reactions returned to normal. Over half the patients with an abnormal initial MARS MRI scan 46/85 (54%), with either Type 1 or 2 abnormal soft tissue reaction, had progressed to more severe types following a mean interval scan time of 12.2 months. Discussion. A safe interval for a follow-up MARS MRI scanning in a patient who has normal initial findings appears to be 12 months. We consider a 6-month scan appropriate for patients under surveillance who have initial abnormal cross-sectional imaging

Summary. When a TFCC tear is diagnosed, practitioners should maintain a high level of suspicion for the presence of a concomitant SL or LT ligament tear. Introduction. Disruption of the scapholunate (SL) or lunotriquetral (LT) ligament leads to dorsal and volar intercalated segment instability, respectively, while triangular fibrocartilage complex (TFCC) tears result in distal radioulnar joint (DRUJ) instability. Viegas et al. (1993) demonstrated that 56% of grossly visualised cadaveric wrists had one or more tears of a ligament or of the TFCC. The purpose of this investigation is to quantify the incidence, distribution, and correlation of SL, LT, and TFCC tears in a large group of cadaver wrists using magnetic resonance imaging (MRI). Additionally, statistical analysis was performed to predict. Methods. Spin density weighted, fat suppressed, and STIR MRI scans of the wrist were obtained in 48 fresh frozen cadaver arms using a 3 Tesla MRI scanner. The scans were scrutinised by one of us (PC) – a board certified musculoskeletal radiologist. The dorsal, volar, and membranous portions of the SL and LT ligaments were examined sequentially for the presence of a tear. Similarly, the central disk and radioulnar attachments of the TFCC were inspected for tears. Results. A ligament or the TFCC was labeled as torn if there was a complete tear, partial tear, or perforation of one or more of its components, but not if sole degenerative changes, thinning, or fraying of the fibers was observed. Four of the 48 images could not be interpreted due to unsatisfactory scans. The most prevalent injury was a TFCC tear, which was present in 28 (64%) of the 44 wrists examined. SL ligament tears were discovered in 20 (45%) of the wrists, and LT tears were present in 14 (32%) of the wrists. Moreover, 45% of the wrists examined had a TFCC tear and either a SL or LT ligament tear. Specifically, 50% of the 28 wrists with a TFCC tear had a concomitant LT tear, and 46% had a concomitant SL tear. Discussion. SL, LT, and TFCC tears were found in a substantial portion of the wrists examined. Moreover, the majority of wrists with a TFCC tear also had a SL or LT ligament tear. Viegas et al. found that 70% of wrists with a TFCC perforation also had a LT ligament tear. In our series, 71% had a TFCC tear, and 50% of those had a concomitant LT tear

Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign lesion of bone originally described by Nora et al in 1983. To date there are no UK-based case series in the literature. Here we present the Scottish Bone Tumour Registry (SBTR) experience of this rare lesion. A retrospective analysis of SBTR records was performed. Histological specimens were re-examined by a consultant musculoskeletal oncology pathologist. Radiographs were re-reported by a consultant musculoskeletal radiologist. From 1983-2009, 13 cases were identified; 6 male, 7 female. Age ranged from 13-65. All patients presented with localised swelling. Pain was present in 5 and trauma in 2. 9 lesions affected the hand, 3 the foot, and 1 the tibial tuberosity. 12 lesions were excised and 1 curetted. There were 7 recurrences of which 6 were excised. 1 patients' recurrence was not treated. 1 lesion recurred a second time. This was excised. There were no metastases. Radiographs typically showed densely mineralised lesions contiguous with an uninvolved cortex. Cortical breakthrough was present in 1 case and scalloping in another. Histology characteristically showed hypercellular cartilage with pleomorphism and calcification/ossification without atypia; bone undergoing maturation; and a spindle-cell stroma. SBTR records indicate that BPOP is a rare lesion with no sex predilection that affects patients over a wide age range. Minor antecedent trauma was present in only 2 cases. In agreement with Nora et al. we feel that trauma is unlikely to represent an aetiological factor. Recurrence was over 50% in this series. Although this is similar to that found in other reports, it may indicate that more extensive resection is required for this aggressive lesion. Finally, although radiological/histological findings are often bizarre there have been no reported metastases and so it is important that BPOP is not mistaken for, or treated as, a malignant process such as chondrosarcoma

Medial open-wedge high tibial osteotomy has been gaining popularity in recent years, but adequate supporting material is required in the osteotomy gap for early weight-bearing and rapid union. The purpose of this study was to investigate whether the implantation of a polycaprolactone-tricalcium phosphate composite scaffold wedge would enhance healing of the osteotomy in a micro pig model. We carried out open-wedge high tibial osteotomies in 12 micro pigs aged from 12 to 16 months. A scaffold wedge was inserted into six of the osteotomies while the other six were left open. Bone healing was evaluated after three and six months using plain radiographs, CT scans, measurement of the bone mineral density and histological examination.

Complete bone union was obtained at six months in both groups. There was no collapse at the osteotomy site, loss of correction or failure of fixation in either group. Staining with haematoxylin and eosin demonstrated that there was infiltration of new bone tissue into the macropores and along the periphery of the implanted scaffold in the scaffold group. The CT scans and measurement of the bone mineral density showed that at six months specimens in the scaffold group had a higher bone mineral density than in the control group, although the implantation of the polycaprolactone-tricalcium phosphate composite scaffold wedge did not enhance healing of the osteotomy.

We used a biodegradable mesh to convert an acetabular defect into a contained defect in six patients at total hip replacement. Their mean age was 61 years (46 to 69). The mean follow-up was 32 months (19 to 50). Before clinical use, the strength retention and hydrolytic in vitro degradation properties of the implants were studied in the laboratory over a two-year period. A successful clinical outcome was determined by the radiological findings and the Harris hip score.

All the patients had a satisfactory outcome and no mechanical failures or other complications were observed. No protrusion of any of the impacted grafts was observed beyond the mesh. According to our preliminary laboratory and clinical results the biodegradable mesh is suitable for augmenting uncontained acetabular defects in which the primary stability of the implanted acetabular component is provided by the host bone. In the case of defects of the acetabular floor this new application provides a safe method of preventing graft material from protruding excessively into the pelvis and the mesh seems to tolerate bone-impaction grafting in selected patients with primary and revision total hip replacement.