Volumetric MRI is a promising outcome measure of muscle reinnervation.

The development of outcome measures that can track the recovery of reinnervated muscle would benefit the clinical investigation of new therapies which hope to enhance peripheral nerve repair. The primary objective of this study was to assess the validity of volumetric Magnetic Resonance Imaging (MRI) as an outcome measure of muscle reinnervation by testing its reproducibility, responsiveness and relationship with clinical indices of muscular function. Over a 3-year period 25 patients who underwent nerve transfer to reinnervate elbow flexor muscles were assessed using intramuscular electromyography (EMG) and MRI (median post-operative assessment time of 258 days, ranging from 86 days pre-operatively to 1698 days post- operatively). Muscle power (Medical Research Council (MRC) grade) and Stanmore Percentage of Normal Elbow Assessment (SPONEA) assessment was also recorded for all patients. Sub-analysis of peak volitional force (PVF), muscular fatigue and co-contraction was performed in those patients with MRC > 3. The responsiveness of each parameter was compared using Pearson or Spearman correlation. A Hierarchical Gaussian Process (HGP) was implemented to determine the ability of volumetric MRI measurements to predict the recovery of muscular function. Reinnervated muscle volume per unit Body Mass Index (BMI) demonstrated good responsiveness (R2 = 0.73, p < 0.001). Using the temporal and muscle volume per unit BMI data, a HGP model was able to predict MRC grade and SPONEA with a mean absolute error (MAE) of 0.73 and 1.7 respectively. Muscle volume per unit BMI demonstrated moderate to good positive correlations with patient reported impairments of reinnervated muscle; co- contraction (R2 = 0.63, p = 0.02) and muscle fatigue (R2 = 0.64, p = 0.04). In summary, volumetric MRI analysis of reinnervated muscle is highly reproducible, responsive to post-operative time and demonstrates correlation with clinical indices of muscle function. This encourages the view that volumetric MRI is a promising outcome measure for muscle reinnervation which will drive advancements in motor recovery therapy.

Introducing image-guided synovial aspiration and biopsy in assessing peri-prosthetic joint infection: an early single-centre experience.

AIM: Synovial sampling can be used in the diagnosis of peri-prosthetic joint infection (PJI). The purpose of this study was to establish the role of simultaneous image-guided synovial aspiration and biopsy (SAB) during an initial 2-year experience at our institution. METHODS: Retrospective review of consecutive SABs performed during 2014-2016 at a tertiary referral musculoskeletal centre. Radiological SAB microbiology culture results were compared with intra-operative surgical samples or multidisciplinary team (MDT) meeting outcome at 1-year follow-up if surgery was not undertaken. Sensitivity, specificity and accuracy of synovial aspiration (SA), synovial biopsy (SB) and simultaneous SAB were calculated. RESULTS: 103 patients (46 male, 57 female) totalling 111 procedures were analysed with mean age 65 years (range 31-83). Image-guided synovial procedures were performed on 52 (46.9%) hip and 59 (53.1%) knee joint prostheses. The mean combined sensitivity, specificity and accuracy for the entire cohort was 72.6%, 96.9% and 90%, respectively. When only SB was obtained, diagnostic accuracy (92.5%) was similar to SA alone (94.1%). In total, there were 21 (18.9%) true-positive, 80 (72.1%) true-negative, 2 (1.8%) false-positive and 8 (7.2%) false-negative cases (PPV 91.3% and NPV 90.9%). No post-procedural complications were recorded at 1-year follow-up. CONCLUSION: Percutaneous image-guided SAB is a valuable technique in assessing suspected PJI, with most samples indicative of infective status and causative organisms when validated against intra-operative results and specialist MDT evaluation. Image-guided SB is a safe and useful additional procedure following failed SA with equivalent levels of diagnostic accuracy.

Providing a paediatric trauma and orthopaedics service during the peak of the COVID-19 pandemic: The Royal National Orthopaedic Hospital experience.

INTRODUCTION: In response to the COVID-19 pandemic, there was a rapidly implemented restructuring of UK healthcare services. The The Royal National Orthopaedic Hospital, Stanmore, became a central hub for the provision of trauma services for North Central/East London (NCEL) while providing a musculoskeletal tumour service for the south of England, the Midlands, and Wales and an urgent spinal service for London. This study reviews our paediatric practice over this period in order to share our experience and lessons learned. Our hospital admission pathways are described and the safety of surgical and interventional radiological procedures performed under general anaesthesia (GA) with regards to COVID-19 in a paediatric population are evaluated. METHODS: All paediatric patients (≤ 16 years) treated in our institution during the six-week peak period of the pandemic were included. Prospective data for all paediatric trauma and urgent elective admissions and retrospective data for all sarcoma admissions were collected. Telephone interviews were conducted with all patients and families to assess COVID-19 related morbidity at 14 days post-discharge. RESULTS: Overall, 100 children underwent surgery or interventional radiological procedures under GA between 20 March and 8 May 2020. There were 35 trauma cases, 20 urgent elective orthopaedic cases, two spinal emergency cases, 25 admissions for interventional radiology procedures, and 18 tumour cases. 78% of trauma cases were performed within 24 hours of referral. In the 97% who responded at two weeks following discharge, there were no cases of symptomatic COVID-19 in any patient or member of their households. CONCLUSION: Despite the extensive restructuring of services and the widespread concerns over the surgical and anaesthetic management of paediatric patients during this period, we treated 100 asymptomatic patients across different orthopaedic subspecialties without apparent COVID-19 or unexpected respiratory complications in the early postoperative period. The data provides assurance for health care professionals and families and informs the consenting process.Cite this article: Bone Joint Open 2020;1-6:287-292.

Description of the MRI and ultrasound imaging features of giant epidermal cysts.

OBJECTIVES: Guidelines suggest that lesions over 5 cm in dimension should be referred to a specialist sarcoma centre due to the possibility of malignancy. Few epidermal cysts (ECs) reach or exceed this size and are termed giant ECs (GECs). The purpose of this study is to report on a large series of GECs. METHODS: Retrospective review of histologically proven GECs over an 8-year period. Patient demographics with MRI and ultrasound (US) appearances were evaluated. RESULTS: A total of 14 cases were included with eight males and six females. Mean age was 51 years. 11 lesions were oval and three bi-lobed in shape, while 12 demonstrated dermal apposition. All were hyperintense on water-sensitive sequences and isointense to slightly hypointense on T1W imaging. Internal clefts were seen in 13 cases and 11 demonstrated chemical shift artefact (CSA) on MRI. On US, 12 showed well-defined linear hypoechoic clefts, with 66.6% having dis-organised compared with 33.3% peripherally located clefts. One 'pseudo testis' pattern and one showing irregular striped echogenicity termed novel 'pseudo muscle' appearance. No cases demonstrated internal vascularity on Doppler US. CONCLUSIONS: MRI signal findings of GECs are often characteristic with hyperintensity on water-sensitive sequences, dermal apposition, CSA and internal clefts while US features of disorganised or clumped hypoechoic clefts and absence of neovascularity were commonly seen. Recognition of combinations of both US and MRI features of GECs should reduce the requirement for pre-excisional needle biopsy to confirm the diagnosis. ADVANCES IN KNOWLEDGE: 1. Identification of common imaging features of GECs should avoid unnecessary pre-excisional biopsy despite their large size in the appropriate MDT setting.2. A novel 'pseudo-muscle' appearance is described on MRI and US.

The uncrossed-doubled patellar tendon: A novel imaging finding.

A spectrum of anatomic variants of the conventional single patellar tendon have been described however a double patellar tendon is a highly rare finding, which has only been described once before where a cross-over tendon morphology was illustrated. We report the case of a 46-year-old man with a 3 month history of left knee pain who was found to have an incidental double patellar tendon without cross-over, with one deep bundle demonstrating a more conventional patellar tendon course, paralleled by a second anatomically-distinct superficial bundle of differing morphology coursing anterolateral to the deep conventional bundle, explicitly connecting patella to tibial tuberosity. A comprehensive understanding of the anatomic variations of the patellar tendon is essential for both radiologist and clinician to deliver safe clinical practice. We present a rare case of an uncrossed-doubled patellar tendon, which to our knowledge, has never been reported.

A novel ceramic coating for reduced metal ion release in metal-on-metal hip surgery.

An ovine total hip arthroplasty model was developed to evaluate metal ion release, wear, the biological response and adverse tissue reaction to metal-on-metal (MoM) bearing materials. The performance of an advanced superlattice ceramic coating (SLC) was evaluated as a bearing surface and experimental groups divided into; (1) MoM articulating surfaces coated with a SLC coating (SLC-MoM), (2) uncoated MoM surfaces (MoM), and (3) metal on polyethylene (MoP) surfaces. Implants remained in vivo for 13 months and blood chromium (Cr) and cobalt (Co) metal ion levels were measured pre and postoperatively. Synovial tissue was graded using an ALVAL scoring system. When compared with the MoM group, sheep with SLC-MoM implants showed significantly lower levels of chromium and cobalt metal ions within blood over the 13-month period. Evidence of gray tissue staining was observed in the synovium of implants in the MOM group. A significantly lower ALVAL score was measured in the SLC-MoM group (3.88) when compared with MoM components (6.67) (p = 0.010). ALVAL results showed no significant difference when SLC-MOM components were compared to MoP (5.25). This model was able to distinguish wear and the effect of released debris between different bearing combinations and demonstrated the effect of a SLC coating when applied onto the bearing surface. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1760-1771, 2019.

Small, superficial, indeterminate soft-tissue lesions as suspected sarcomas: is primary excision biopsy suitable?

OBJECTIVE: Suspected soft-tissue sarcomas are typically investigated using magnetic resonance imaging (MRI), with a view to planning image-guided core needle biopsy for confirmation of the histological diagnosis. Indeterminate superficial lesions may be small and therefore potentially difficult to biopsy safely, such lesions possibly being more amenable to primary excision biopsy. The aim of this study is to determine the suitability of this practice in the setting of a specialist sarcoma service. MATERIALS AND METHODS: All patients referred over a 12-month period to the sarcoma service with a small (<3-cm), indeterminate, superficial soft-tissue mass according to MRI criteria, or a small lesion of the hand or foot deemed unsafe for percutaneous biopsy, and who underwent primary excision biopsy were included. The histology results were categorized into neoplastic and non-neoplastic lesions, and assessed for resection completeness. RESULTS: Fifty-eight patients fulfilled the inclusion criteria from all patients referred to the sarcoma service in a 12-month period. Of these, 42 out of 58 (72.4%) had benign neoplasms, 4 out of 58 (6.9%) had malignant tumours, 2 out of 58 (3.4%) an intermediate grade lesion, while 10 out of 58 (17.2%) were non-neoplastic. All 4 malignant lesions were completely excised at the time of excision biopsy. CONCLUSIONS: Primary excision biopsy of small, indeterminate soft-tissue masses within the setting of a specialist sarcoma service is a suitable management option. Only a small proportion of small superficial soft-tissue lesions with indeterminate MRI features are malignant tumours.

Skeletal Manifestations of Osteogenesis Imperfecta.

The skeletal manifestations of osteogenesis imperfecta are investigated. The antenatal and postnatal diagnosis of the disease is briefly mentioned and the characteristic appearances of bone deformities are analyzed in detail. The distinctive bony manifestations of osteogenesis imperfecta are illustrated using typical examples. Finally, we comment on the differential diagnosis.

Imaging of the Painful Hip Arthroplasty.

The incidence of complications following total hip arthroplasty is low, but due to the frequency of the procedure, they are quite commonly encountered and require appropriate investigation. Complications include aseptic loosening, infection, foreign body granulomatosis (osteolysis), adverse reactions to metal debris, periprosthetic fracture, heterotopic ossification, hardware failure, and a range of soft tissue complications, all of which may result in pain. Relevant imaging findings are illustrated and the role of various imaging modalities is reviewed. A suggested approach for the radiological investigation of each potential complication is outlined, based on our experience at a specialist referral unit.

Is balloon kyphoplasty safe and effective for cancer-related vertebral compression fractures with posterior vertebral body wall defects?

BACKGROUND AND OBJECTIVES: Balloon kyphoplasty (BKP) is a percutaneous treatment for cancer-related vertebral compression fractures (VCF). Posterior vertebral body wall (PVBW) involvement is considered a contraindication for BKP. This study assesses whether BKP is safe and effective for cancer-related VCFs involving the PVBW. METHODS: This study analyzed data on 158 patients with 228 cancer-related VCFs who underwent BKP. One hundred and twelve patients had VCFs with PVBW defects, and 46 had VCFs with no PVBW defect. Outcomes were assessed preoperatively and at 3 months. RESULTS: In the PVBW defect group, mean pain score decreased from 7.5 to 3.6 (P < 0.001), EQ5D increased from 0.39 to 0.48 and Oswestry Disability Index (ODI) decreased from 50 to 42. Cement leaks occurred in 31%. In the PVBW intact group, mean pain decreased from 7.3 to 3.3 (P < 0.001), EQ5D increased from 0.35 to 0.48 (P < 0.001), and ODI decreased from 53 to 50. Cement leaks occurred in 20%. No significant difference was observed in functional improvements between groups. Radiographically kyphotic angle and anterior and middle vertebral body heights were significantly worse in the PVBW defect group (P < 0.05). CONCLUSIONS: BKP can alleviate pain and improve QoL and function in patients with cancer-related VCFs with PVBW defects with no appreciable increase in risk. J. Surg. Oncol. 2016;113:835-842. © 2016 Wiley Periodicals, Inc.

Intracortical intraosseous lipoma.

Intraosseous lipomas are very uncommon, benign primary bone lesions with an incidence of <1%. The overwhelming majority occur within the intramedullary canal. We present an uncommon intracortical intraosseous lipoma with 3 T MRI findings to help differentiate this from other differential diagnoses.

Melanotic schwannoma: an 11-year case series.

Melanotic or melanocytic schwannoma is a rare tumour usually involving spinal nerve roots but can also present at other anatomical locations. Although there are less than 200 cases reported, melanotic schwannomas can have distinctive imaging features but there is limited recent literature on its often characteristic radiological appearances. Recent publication of the largest case series thus far has suggested melanotic schwannoma to be a separate entity to other schwannomata and that its reclassification to a malignant lesion be under consideration. We present a case series over an 11-year period to highlight salient imaging features with reference to the current concerns regarding its malignant potential.

Functional outcome following primary total knee arthroplasty cannot be predicted using the initial post-operative radiograph.

Obtaining standardised post-operative radiographs following total knee arthroplasty is common practice. Little is known regarding how measurements taken from the initial post-operative radiograph correlate to functional outcome. The initial post-operative radiographs for 110 primary total knee arthroplasties were reviewed retrospectively. Femoral and tibial component alignment was measured by two independent consultant radiologists. Functional outcome was assessed by the Oxford Knee Score pre-operatively and one year post-operatively. Correlation was determined by Pearson correlation analysis. There was no significant correlation between the radiographic measurements with the one year post-operative Oxford Knee Score nor was there significant correlation with the difference in pre-operative and post-operative scores. The initial post-operative radiograph cannot be used as a tool to reliably predict functional outcome at one year.

Musculoskeletal injuries related to yoga: imaging observations.

OBJECTIVE: The purpose of this article is to describe the imaging appearances of musculoskeletal injuries related to yoga. We performed an automated search in the database of a large tertiary care center and conducted a retrospective analysis of the imaging findings in 38 patients over a 9-year period. CONCLUSION: The most frequently encountered musculoskeletal injuries were tendinous lesions, including tears of the supraspinatus, Achilles, and peroneus brevis tendons and fibrocartilaginous tears involving the medial meniscus, acetabular labrum, glenoid labrum, and lumbar disk with extrusion.

An overview of vertebroplasty: current status, controversies, and future directions.

Vertebroplasty is a cost-effective procedure for the relief of pain in appropriately selected patients when performed by a skilled practitioner. The currently accepted indications and contraindications for vertebroplasty are reviewed. The techniques routinely used by the authors are presented, including a discussion of recognized complications. Recent controversy has highlighted weaknesses in the practice of technology evaluation, and more robust studies will be required to address these issues across the board in the future more scientifically than has been done in the past.

Magnetic resonance imaging and radiographic assessment of carpal depressions in children with juvenile idiopathic arthritis: normal variants or erosions?

OBJECTIVE: Magnetic resonance imaging (MRI) is playing an increasingly important role in the diagnosis and followup of juvenile idiopathic arthritis (JIA). Carpal depressions are commonly observed in healthy children and in patients with JIA. The aim of our study was to further characterize these depressions in patients with JIA. METHODS: A total of 29 MRI wrist examinations were analyzed. Depressions were classified according to morphology as either tubular or focal. Features including the presence of a vessel related to the depression, evidence of synovitis, bone marrow edema, or loss of joint space on a radiograph taken on the same day were recorded for each depression. RESULTS: A total of 173 depressions were identified in 145 carpal bones. Forty percent were capitate depressions. A third were focal depressions and two-thirds were tubular. About 10% of tubular depressions and 30% of focal depressions were associated with features suggesting true erosions, with the remainder likely to represent vascular channels and normal variants. CONCLUSION: Radiologists and clinicians should undertake caution when assessing carpal depressions on MRI because the vast majority are likely to represent normal variants.

Percutaneous vertebral augmentation: the status of vertebroplasty and current controversies.

Vertebroplasty is a cost-effective procedure for the relief of pain and suffering in the appropriate patient when done by a skilled practitioner under good image guidance. No study has ever shown any cost benefit of any balloon-based osteoporotic spine intervention over simple vertebroplasty. No study has ever shown any benefit of any intravertebral implant over vertebroplasty for osteoporotic compression fracture. Recent controversy has highlighted weaknesses in our practice of technology evaluation, and we need to address these issues across the board in the future more scientifically then we have done in the past.