Radiological angle assessment of Haglund's deformity: validation on Magnetic Resonance Imaging

PURPOSE

Haglund's deformity, an abnormality at the postero-superior corner of the calcaneus is a common cause of posterior heel pain. To date numerous measurements of radiological angles related to the calcaneus have been proposed to differentiate between symptomatic and asymptomatic patients with the deformity. Traditionally, these measurements have been assessed on plain radiographs. The aim of this study was to identify measurements which can be applied to Magnetic Resonance Imaging (MRI) studies of the ankle.

METHODS

A retrospective cohort analysis of 30 MRI ankle studies from patients with symptomatic Haglund's deformity and 32 normal studies as controls was undertaken. The angle of BRINK, the Achilles angle, Calcaneal pitch, Achilles-plantar fascia angle and soleus calcaneal distance were measured on optimal T2 fat-saturated sagittal slices.

RESULTS

There was a statistically significant difference (p < 0.0001) in the angle of BRINK between the Haglund's and control group. The Area-Under-the-Curve (AUC) was 0.7783 in keeping with good discrimination between the two groups. The angle of BRINK measurement is reproducible, with an intra-observer ICC of 0.837 and an inter-observer ICC of 0.824. There was no statistically significant difference between the two groups for the other measurements. In the Haglund's group the Achilles tendon was more likely to attach to the mid 1/3 of the posterior calcaneus as opposed to the superior 1/3 (p = 0.02), calcaneal oedema was more likely to be present (p < 0.001) and non-insertional tendinopathy was more likely to be present (p < 0.001). The presence of a retrocalcaneal bursa is non-specific (p = 0.602).

CONCLUSION

The angle of BRINK demonstrates good discrimination between normal and Haglund's cases on MRI studies and may improve patient management by supporting surgical decision-making. Future work should correlate the angle of BRINK to long-term outcomes.

Right-sided meralgia paresthetica from lateral femoral cutaneous nerve neuroma

Meralgia Paresthetica (MP) causes outer thigh discomfort, numbness, and tingling. Compression or injury to the Lateral Femoral Cutaneous Nerve (LFCN), which gives sensory innervation to outer aspect of the thigh. It frequently gets impinged beneath the inguinal ligament resulting in in sensory impairment in the distribution of LFCN. Compression of the LFCN is a frequent cause of MP, whereas LFCN neuromas is a rare cause. This case report describes a unique case of Meralgia Paresthetica produced by a LFCN neuroma and enhances our knowledge of Meralgia Paresthetica.

Current updates in MSK infection imaging: A narrative review

This article presents a comprehensive overview of the diagnostic utility of existing imaging techniques including radiography, computed tomography, ultrasonography, magnetic resonance imaging (MRI), and radionuclide imaging in the context of the most common orthopaedic or musculoskeletal infections. It also includes illustrative images showcasing significant findings in various musculoskeletal infections including osteomyelitis, cellulitis, septic arthritis, necrotising infections and peri-prosthetic joint infections and their associated complications.

Assessing bone density on MRI: comparison between routine MRI sequences and DEXA scans

PURPOSE

Magnetic Resonance Imaging (MRI) is frequently utilised to aid in the comprehensive assessment of back pain, while dual-energy x-ray absorptiometry (DEXA) is the gold standard test for the assessment of bone density. Assessing bone density on MRI could reduce costs and avoid exposing patients to ionising radiation. The aim of this paper is to investigate whether the relative signal intensity of vertebral bodies compared to other structures can detect osteoporosis on MRI.

METHODS

100 patients that had undergone both a lumbar spine MRI and a DEXA scan were identified. The T1 and T2 signal intensity of L1-L4 vertebral bodies (VB), cerebro-spinal fluid (CSF), and psoas muscle were measured within a 1-cm2 region of interest (ROI), and the signal intensity ratios were calculated. The ratios were stratified as normal, osteopenic, or osteoporotic based on DEXA T-scores.

RESULTS

The T1 VB /T1 CSF ratio was significantly higher in the osteoporotic group than the normal and osteopenic groups (p < 0.001). The T1 VB /T1 CSF ratio had excellent discrimination (AUC = 0.841) for the presence of osteoporosis. The Pearson correlation coefficient between the DEXA T-score and the T1 VB/T1 CSF ratio was -0.474 (p < 0.001). The intra-observer (ICC = 0.910, 95% CI = 0.757-0.966) and inter-observer reliability (ICC = 0.927, 95% CI = 0.824-0.970) were excellent. In our cohort, a T1 VB / T1 CSF ratio of greater than 4 is 66.7% sensitive but 90.0% specific for the presence of osteoporosis.

CONCLUSION

A high T1 VB/T1 CSF ratio suggests osteoporosis on MRI. Prospective validation is needed to confirm these findings.

Validity of ChatGPT-generated musculoskeletal images

OBJECTIVE

In the evolving landscape of medical research and radiology, effective communication of intricate ideas is imperative, with visualizations playing a crucial role. This study explores the transformative potential of ChatGPT4, a powerful Large Language Model (LLM), in automating the creation of schematics and figures for radiology research papers, specifically focusing on its implications for musculoskeletal studies.

MATERIALS AND METHODS

Deploying ChatGPT4, the study aimed to assess the model's ability to generate anatomical images of six large joints-shoulder, elbow, wrist, hip, knee, and ankle. Four variations of a text prompt were utilized, to generate a coronal illustration with annotations for each joint. Evaluation parameters included anatomical correctness, correctness of annotations, aesthetic nature of illustrations, usability of figures in research papers, and cost-effectiveness. Four panellists performed the assessment using a 5-point Likert Scale.

RESULTS

Overall analysis of the 24 illustrations encompassing the six joints of interest (4 of each) revealed significant limitations in ChatGPT4's performance. The anatomical design ranged from poor to good, all of the illustrations received a below-average rating for annotation, with the majority assessed as poor. All of them ranked below average for usability in research papers. There was good agreement between raters across all domains (ICC = 0.61).

CONCLUSION

While LLMs like ChatGPT4 present promising prospects for rapid figure generation, their current capabilities fall short of meeting the rigorous standards demanded by musculoskeletal radiology research. Future developments should focus on iterative refinement processes to enhance the realism of LLM-generated musculoskeletal schematics.

An evaluation of AI generated literature reviews in musculoskeletal radiology

PURPOSE

The use of artificial intelligence (AI) tools to aid in summarizing information in medicine and research has recently garnered a huge amount of interest. While tools such as ChatGPT produce convincing and naturally sounding output, the answers are sometimes incorrect. Some of these drawbacks, it is hoped, can be avoided by using programmes trained for a more specific scope. In this study we compared the performance of a new AI tool (the-literature.com) to the latest version OpenAI's ChatGPT (GPT-4) in summarizing topics that the authors have significantly contributed to.

METHODS

The AI tools were asked to produce a literature review on 7 topics. These were selected based on the research topics that the authors were intimately familiar with and have contributed to through their own publications. The output produced by the AI tools were graded on a 1-5 Likert scale for accuracy, comprehensiveness, and relevance by two fellowship trained consultant radiologists.

RESULTS

The-literature.com produced 3 excellent summaries, 3 very poor summaries not relevant to the prompt, and one summary, which was relevant but did not include all relevant papers. All of the summaries produced by GPT-4 were relevant, but fewer relevant papers were identified. The average Likert rating was for the-literature was 2.88 and 3.86 for GPT-4. There was good agreement between the ratings of both radiologists (ICC = 0.883).

CONCLUSION

Summaries produced by AI in its current state require careful human validation. GPT-4 on average provides higher quality summaries. Neither tool can reliably identify all relevant publications.

Comparison of patterns and rates of cement leakage in percutaneous sacroplasty for sacral insufficiency fractures versus neoplasia

OBJECTIVE

Percutaneous sacroplasty is a minimally invasive procedure which utilises injection of bone cement into the sacrum for stabilisation of osteoporotic sacral insufficiency fractures (SIF) and neoplastic lesions to relieve pain and improve function. While effective, cement leakage is an important complication associated with the procedure. This study aims to compare the incidence and patterns of the cement leakages following sacroplasty for SIF versus neoplasia and discuss the various patterns of cement leakage and their implications.

MATERIALS AND METHODS

This retrospective study analysed 57 patients who underwent percutaneous sacroplasty at a tertiary orthopaedic hospital. Patients were divided into 2 groups of SIF (n=46) and neoplastic lesions (n=11) based on their indication for sacroplasty. Pre- and post-procedural CT fluoroscopy was used to assess for cement leakage. The incidence and patterns of cement leakage were both compared among the two groups. A Fisher's exact test was used for statistical analysis.

RESULTS

Eleven (19%) patients had cement leakage on post-procedural imaging. The most common sites of cement leakage were into the presacral region (6), followed by sacroiliac joints (4), sacral foramina (3) and posterior sacral (1). There was a statistically significant higher incidence of leakage in the neoplastic group in comparison to SIF group (P-value <0.05). The incidence of cement leakage in the neoplastic group was 45% (n = 5/11) versus SIF 13% (n=6/46).

CONCLUSION

There was a statistically significant higher incidence of cement leak in sacroplasties conducted for the treatment of neoplastic lesions compared to those with sacral insufficiency fracture.

Isolated lesions of the pubis

The osseous pelvis is a well-known area of various primary and secondary bone tumours, tumour mimics, and infections. Isolated lesions of the pubis (ILP) are rare, with few case reports in the literature. Given their sparsity, such lesions may pose a great diagnostic challenge due to varied clinical presentations and imaging features. In this study, we report the largest case series of ILP. We discuss the patient demographics, differentials, surgical approaches, and management.

Imaging in international sporting event: experience from the Birmingham Commonwealth Games 2022

AIM

To explain the design and delivery of diagnostic imaging and image-guided intervention services for an international games. The authors share their experiences from the Birmingham Commonwealth Games 2022.

MATERIALS AND METHODS

A retrospective analysis was undertaken of anonymised data from the Zillion, Easyvision (RIS and PACS), and Encounter platforms for image viewing, interpretation and reporting during the Games. The data collected included age and gender, type of sport, nature of the injury, and imaging findings with diagnoses.

RESULTS

The number of individuals who had radiological investigations at the Birmingham Commonwealth Games was 518 and the vast majority of them were athletes (90 %). The average age of athletes who had imaging was 28 years and that of non-athletes who accessed imaging services was 46.4 years with male predominance. Magnetic resonance imaging was the most frequently used imaging technique and the lower limb was the most frequently imaged body part. Athletes playing netball and beach volleyball had the highest percentage of injuries.

CONCLUSION

The authors share their experience from the Birmingham Commonwealth Games 2022 regarding the nuances and challenges in radiology service provision for an international sports event that would be helpful for musculoskeletal radiologists in the design and delivery of similar international events in the future.

Isolated, periosteal stripping injuries of the Flexor Retinaculum: Case series of 3 patients with clinico-radiological review

Isolated periosteal avulsion injuries of the flexor retinaculum on the medial side of the ankle are rare and may mimic osseous injuries or deltoid ligament tears. We describe a case series of 3 individuals with isolated, stripping injuries of the tibial attachment of the flexor retinaculum without underlying fracture or deltoid ligament disruption. A new classification system of flexor retinaculum periosteal stripping injuries of the ankle is proposed with clinico-radiological features.

Primary synovial chondromatosis of the hip joint (PrSC of the hip): A retrospective cohort analysis and review of the literature

Introduction

Primary synovial osteochondromatosis (SOCM) or Synovial chondromatosis (SC) of the hip is a benign metaplastic condition of the synovium that is rare and may present with a spectrum of clinical features and radiological findings.

Patients and methods

A retrospective search using the keyword 'Synovial chondromatosis' (SC) of the hip was performed at a tertiary care orthopaedic referral centre in the UK and a hospital in India. The radiology images were collected from our Picture Archiving and Communication System (PACS) and Radiology Information System (RIS), over 15 years. The patient's data was collated with Electronic Patient Records (EPR), RIS, and correlated with histo-pathology laboratory records where available. The demographic details of the patients, their clinical symptoms, imaging details, and management outcomes were collected.

Results

We found 15 cases, with a mean age of 36.53 years (range: 14-50 years). There were 9 male and 6 female patients. The follow-up ranged from 1 year to 6 years. Predominantly unilateral presentation with insidious onset of symptoms was found. A spectrum of radiological Imaging was undertaken. Management strategies included supervised observation, arthroscopic or open synovectomy, and hip arthroplasty. No malignant transformation was found in the analysed cohort.

Conclusion

Primary 'Synovial chondromatosis' of the hip had a male preponderance in our cohort, presenting with a range of clinical features. Radiologically, Magnetic Resonance Imaging (MRI) was the commonest modality of cross-sectional imaging utilised and crucial for the diagnosis, evaluating underlying articular involvement including guiding appropriate patient management presenting with Primary 'Synovial chondromatosis' of the hip.

775 Role of Inversion Imaging in the Diagnoses of Neck of Femur Fractures

Aim

The objective of this study was to assess whether inversion of grey scale radiograph images has any impact on the diagnostic sensitivity and inter-observer reliability in diagnosing neck of femur fractures.

Method

We performed a retrospective, single centre study, using 50 randomly selected AP pelvis radiographs. The images included a combination of normal, intracapsular and extracapsular neck of femur fractures, which had been confirmed on CT, MRI and/or subsequent surgery.

Four independent observers (two orthopaedic specialists, one registrar and one SHO in orthopaedics) reviewed the images and graded each radiograph image using the Likert scale in response to the statement “there is a fracture”. Following this, the same radiographs were inverted to grey scale images and sent for a second review using the same method. RAND correlation was used for statistical analysis.

Results

Overall, observers appeared to have similar accuracy and equivocal rates with normal and inversion radiographic imaging.

One of the T&O Consultant's had much higher equivocal rate when analysing inverted radiographs compared to conventional digital radiographs but had slightly higher accuracy with inversion (95.35% compared to 93.88%) as well as the Registrar (83.33% compared to 81.63%). The second Trauma and Orthopaedics Consultant had slightly more accuracy with conventional digital radiographs (89.58% compared with 87.50%).

Conclusions

Inversion of digital radiographs did not affect the diagnostic sensitivity of neck of femur fractures in our study, and similarly did to not have a statistically significant impact in clinician confidence in diagnosing neck of femur fractures.

609 Metachronous Osteoid Osteoma of the Mid-Diaphysis of the Fibula and Distal Humerus: A Case Report

A 7-year-old boy presented with a 4-week history of pain and swelling of the right leg. He had a history of mucoepidermoid carcinoma of the parotid gland, treated by surgical resection without any complication. There was no other significant past medical history. A radiograph of the right leg showed a lytic lesion of the right diaphysis of the fibula with periosteal reaction. An MRI of the right leg showed osteoid osteoma of the fibula with marked cortical thickening with osseous and soft tissue oedema. The patient subsequently had a Jamshidi biopsy and curettage of the lesion, with the histopathological results of the biopsy showing fragments of a typical osteoid osteoma nidus with irregular calcified bony lamellae. His symptoms had significantly improved after the procedure, and he was ambulating without any discomfort or pain. The patient remained asymptomatic until he returned seven years later with right elbow swelling, pain and reduced range of movement over 2–3 months. A radiograph of the elbow joint had shown a large effusion with a sclerotic lesion on the coronoid fossa of the distal humerus in keeping with an osteoid osteoma. The patient had a confirmational biopsy and subsequently radiofrequency ablation of the lesion with complete resolution of pain. To our knowledge, our case is an atypical presentation of osteoid osteoma in two widely separate bones, between the lower and the upper limb separated by seven years disease-free interval.

Calcaneal offset index to measure hindfoot alignment in pes planus

INTRODUCTION

Pes planus is a common three-dimensional (3D) deformity characterised by forefoot abduction, the collapse of the medial longitudinal arch, and hindfoot valgus. Several radiological measurements such as anteroposterior talocalcaneal angle (Kite's) and 'Calcaneal pitch angle' (CPA) exist to calculate the degree of hindfoot alignment in these patients with variable intra- and interobserver reliability.

OBJECTIVE

To describe a new radiological ancillary method of measuring hindfoot alignment, the calcaneal offset index (COI).

MATERIAL AND METHODS

Anteroposterior (mortise) and lateral view weight-bearing (WB) ankle radiographs of 200 consecutive patients referred for foot and ankle pain were reviewed. Demographic details, clinical indication, and COI calculation were undertaken on the mortise view along with the measurement of CPA for each patient. A one-way analysis of variance (ANOVA) was performed. Intraclass correlation coefficient (ICC) analysis was evaluated to assess the intraclass reliability between observers.

RESULTS

There was a female preponderance of 2:1 in the study population with a mean age of 51.21 years (13-86 years). The calcaneal offset was increased in pes planus (hindfoot valgus). The p-value was 0.00023 on ANOVA. The COI gave an excellent interobserver correlation with ICC of 0.9 and moderate intraobserver reliability on the ICC analysis of 0.55.

CONCLUSION

The COI can be an additional index of measuring hindfoot alignment in patients with pes planus. Contrary to the traditional angular measurements, this linear transverse plane measure is easier to calculate and reproducible. COI measurement has shown moderate intraobserver reliability but excellent interobserver reliability.

The influence of site on the incidence and diagnosis of solitary central cartilage tumours of the femur. A 21st century perspective

OBJECTIVE

To determine the incidence of central cartilage tumours (CCTs) in the femur and the impact of site (proximal, mid and distal thirds) on tumour grade. To compare study results with historically published data.

MATERIALS AND METHODS

Retrospective review of solitary CCTs arising in the femur over the past 13 years. Data collected included location (proximal, mid and distal thirds) and final diagnosis in terms of tumour grade based on imaging features ± histology. Case material collected from three bone tumour textbooks provided historical data.

RESULTS

430 solitary CCTs were included in the femur. 73% cases arose in the distal, 3.7% in the mid and 23% in the proximal femur. The ratio of "benign" (combining enchondroma and atypical cartilaginous tumour (ACT)) to higher grade chondrosarcoma (CS) was 11:1 in the distal, 1:1 in the mid and 1:1.5 in the proximal femur, the distribution of benign to malignant tumours being significantly different between the regions (F test, p < 0.05). Comparison with historical data showed a reversal of the benign (enchondroma) to malignant (ACT and higher grade CS) of 30%:70%-84%:16% in the current series.

CONCLUSIONS

The site of origin of a CCT in the femur has an impact on final diagnosis with CS uncommon in the distal as compared with the mid and proximal femur. This is in contradistinction to historical data where the incidence of CS exceeded that of enchondroma at all sites.

Assessing the gender gap in musculoskeletal radiology authorship across three continents: are really the "ladies first"?

AIM

To assess gender-specific authorship trends in musculoskeletal (MSK) radiology in three major radiology journals, Skeletal Radiology (SR), Clinical Radiology (CR) and Indian Journal of Radiology and Imaging (IJRI).

MATERIALS AND METHODS

Retrospective analysis of articles pertaining to MSK radiology was done for the years 2000, 2010, and 2020 for SR and CR and for the years 2010 and 2020 for IJRI. The number and positions of female authors was noted.

RESULTS

Three hundred and twenty-five articles were reviewed after excluding the articles where the gender of one or more authors could not be conclusively determined. In SR, the percentage of female authors increased significantly from 4% in 2000 to 17% in 2010 (p<0.0001) and to 21.9% in 2020 (p<0.0001) with an increase in the percentage of first female authors from 0.8% in 2000 to 4.9% in 2010 and further to 5.4% in 2020. In CR, the percentage of female authors reduced from 13.8% in 2000 to 13.6% in 2010 (p=0.9798 and further reduced to 7% in 2020 (p=0.1592). In IJRI, the percentage of articles with no female authors went down from 36.4% (2010) to 26.7% (2020).

CONCLUSION

There is an upward trend in female authorship in MSK radiology related articles in SR and IJRI with continued under-representation in CR. The first and middle order female authors have shown a significant increase, although the number of last female authors remains very low. Analysis of such trends in academic journals from other subspecialities in medicine needs to be undertaken to confirm or refute the findings of this study.

A Radiologists' Guide to En Bloc Resection of Primary Tumors in the Spine: What Does the Surgeon Want to Know?

En bloc resection in the spine is performed for both primary and metastatic bone lesions and has been proven to lengthen disease-free survival and decrease the likelihood of local recurrence. It is a complex procedure, which requires a thorough multi-disciplinary approach. This article will discuss the role of the radiologist in characterizing the underlying tumor pathology, staging the tumor and helping to predict possible intraoperative challenges for en bloc resection of primary bone lesions. The postoperative appearances and complications following en bloc resection in the spine will be considered in subsequent articles.

Snapping Sartorius tendon due to a medial knee ganglion: an unusual cause of medial knee pain

Snapping of knee could be due to plethora of causes. We describe a case of snapping of Sartorius over a medial knee ganglion that was treated successfully by ultrasound guided aspiration with complete resolution of symptoms.

The Linear Hallux Valgus Offset- A novel way to measure Hallux Valgus

INTRODUCTION

Hallux Valgus (HV) is a complex deformity involving the first ray of the forefoot and a common cause of forefoot pain. Several radiological measurements such as Hallux Valgus Angle (HVA), First Metatarsophalangeal Angle (IMA) and Distal metatarsal articular angle (DMAA) exist to calculate the severity of HV and direct patient management. However, these are angular measurements are prone to error with variable intra- and inter-observer reliability.

PURPOSE

To describe a new radiological linear hallux valgus offset (LHVO) to measure HV deformity.

PATIENT AND METHODS

We performed a retrospective cohort study looking at Antero-posterior, weight-bearing foot radiographs of 100 consecutive patients with forefoot pain referred to our foot and ankle clinic. Demographic details, clinical indication, HVA (hallux valgus angle) and LHVO were measured for each patient and data were analyzed using the student t-test. Intraclass Correlation Coefficient (ICC) analysis was evaluated to assess the intra-class reliability between observers.

RESULTS

There was a female predominance of approximately 2:1, with 51.3 years (range 13-86 years). There was a statistically significant difference of LHVO between normal and hallux valgus cohorts with a p-value of 0.0001. The LHVO gave moderate intra-observer and inter-observer reliability on ICC analysis of 0.7.

CONCLUSION

The LHVO can be an additional measure of assessing severity of hallux valgus. In contrary to the traditional angular measurements, this linear measure is easier to calculate and reproducible on plain, weight bearing radiographs. LHVO measurement has shown a moderate inter-observer reliability in the study to complement traditional radiological evaluation of hallux valgus alignment.

Differential 18F-NaF uptake in various compartments in knee osteoarthritis: an observational study using PET/MRI

AIM

To investigate if the pattern of fluorine-18-labelled sodium fluoride (¹⁸F-NaF) uptake on integrated positron-emission tomography (PET)/magnetic resonance imaging (MRI) of bone marrow lesions (BML) and osteophytes differs between different knee compartments.

MATERIALS AND METHODS

Sixteen patients with no prior history of knee injury with or without pain were recruited for the study. The images of both knees were acquired on simultaneous PET/MRI. The acquisition was done after 45 minutes of intravenous injection of ¹⁸F-NaF 185-370 MBq (5-10 mCi) for 40 minutes. Each knee was divided into eight compartments patella, trochlea, medial central femur, lateral central femur, medial posterior femur, lateral posterior femur, medial tibia, lateral tibia, and cruciate ligament insertion specifically for BML. BML and osteophytes were scored using MRI Osteoarthritis Knee Score (MOAKS) criteria and their corresponding maximum standardised uptake values (SUVmax) recorded.

RESULTS

BML and osteophytes both showed statistically significant differences among knee compartments, i.e., p-value <0.000 and < 0.043 respectively. SUVmax for BML and osteophytes was greatest in the medial tibia.

CONCLUSION

¹⁸F-NaF PET/MRI showed that BML and osteophytes had differential uptake values due to bone remodelling amongst the various knee compartments and this may help to design disease-modifying osteoarthritis drugs in the future.

Alteration of anterior cruciate ligament orientation in knees with trochlear dysplasia: description of a novel angle on MRI

AIM

To assess changes in anterior cruciate ligament (ACL) geometry and inclination in trochlear dysplasia (TD) and analyse their significance.

MATERIALS AND METHODS

Ninety-nine consecutive knees with TD and 23 normal knee magnetic resonance imaging (MRI) examinations were included as controls (n=122). Varying degrees of TD were classified into four distinct groups (A-D) according to the Dejour classification. MRI images were reviewed independently to measure four ACL angles. Interobserver and intra-observer agreements with statistical significance were determined for TD and various angles.

RESULTS

A significant association was found between TD and two measured angles compared with the control group (sagittal ACL and anteromedial ACL angles, p<0.001 for each). The results indicate that TD can predispose to more vertical ACL inclination as measured in the coronal plane on MRI. No association was found with the Blumenstat angle.

CONCLUSION

The present study found significant associations with TD and steeper sagittal ACL, which have been implicated in ACL failure. A novel angle (anteromedial ACL angle) is described which has significant association with TD and is specific for the anteromedial bundle as measured in the coronal plane. Careful consideration of ACL fibre orientation in the coronal plane on MRI is suggested in knees with TD and the use of this newly described angle in assessing ACL reconstruction (ACLR) grafts.

MRI imaging of soft tissues tumours and tumour like lesions-SLAM approach

Imaging is vital in characterising and delineating the extent of soft tissue tumours and there is abundant literature on this. A simplified approach is required to characterise the lesions on MR and we describe a simplified street-smart approach called SLAM (signal, location, age, multiplicity and matrix).

Gray scale inversion imaging (GSI) in Trauma and Orthopaedics

Radiology plays a crucial part in the diagnosis and management of patients. Several techniques have been used to decrease the diagnostic error rate. We discuss the concept, use and advantages of grayscale inversion imaging in orthopedics.

Does T2 inversion aid in identifying disc pathologies?

OBJECTIVE

T2 inversion sequence is used in routine radiology practice mainly to heighten contrast resolution within the region to be studied but no evidence exists in current literature to assess it's true efficacy for lumbar disc degeneration. The objective of this study was to analyse T2 inversion and evaluate it's efficacy in assessment of lumbar disc pathology,.

MATERIALS AND METHODS

This retrospective single-centre study included 50 randomly selected patients presenting with back pain and radiculopathy. T2 inversion sequence was obtained in both axial and sagittal planes in addition to routine sequences. All the Magnetic Resonance Imaging (MRI) procedures were performed on 3T. One senior Musculoskeletal (MSK) radiologist, 2 general radiologists and a spinal surgeon blinded to final results reviewed images for the various disc pathologies individually analysing conventional and T2 inversion images. Data was analysed using Fischer's test and Chi2 test with a p value of <0.05 considered as significant.

RESULTS

Fifty randomly selected patients (mean age was 47.3 years(range 35-55 years) with back pain and radicular symptoms were included. The spectrum of disc pathologies included protrusions, annular fissures, discal cysts and calcified discs. Based on the above findings, T2 inversion sequence is not proved to be an alternative imaging sequence to routine MR imaging sequences for the depiction of various disc pathologies.

CONCLUSION

T2 inversion sequence does not increase the depiction of various lumbar disc pathologies in comparison with conventional sequences when used by experienced MSK radiologists. It may highlight abnormalities better for relatively inexperienced readers such as general radiologists and spinal surgeons.

Intramuscular ossifying metastasis from oesophageal carcinoma, with a pattern distinct from myositis ossificans - A case report

Muscle metastasis is uncommon. We present second reported case of ossifying metastasis from oesophageal carcinoma and review the literature. Our case highlights the different patterns of ossification in muscle, which is essential to make the diagnosis of myositis ossificans, a "don't touch lesion" in contrast to muscle metastasis or tumour, that needs oncological management.

Prevalence of Enchondromas of the Proximal Femur in Adults as an Incidental Finding on MRI of the Pelvis

Objective  To determine the prevalence of enchondroma in adults as an incidental finding in the proximal femur on magnetic resonance imaging (MRI). Materials and Methods  A retrospective review of the MRI scans of the pelvis in a series of adult patients was conducted. All presented with nononcological musculoskeletal complaints. The site, size, and appearances of the enchondromas were identified according to criteria from previous studies. Results  A total of 1,209 proximal femora in 610 patients were reviewed and a total of 9 enchondromas were identified. These ranged from 0.6 to 2.5 cm in length (mean 1.3 cm). None showed aggressive features suggestive of malignancy. Three cases (33%) underwent follow-up MRI scans which showed no change in size or morphology. Conclusion  The prevalence on MRI of incidental enchondromas arising in the proximal femur is 0.7%. This is three to four times less common than seen in the proximal humerus and around the knee.

Vasovagal reactions in ultrasound guided musculoskeletal injections: A study of 2,462 procedures

OBJECTIVE

to determine the rate of the vasovagal reaction (VVR) in ultrasound guided musculoskeletal injections (USGIs) and to investigate effect of injection site, age, and gender on this rate.

MATERIAL AND METHODS

Retrospective analysis of all USGIs performed from the 1st of January 2019 to the 31st of December 2019 in single tertiary orthopaedic hospital. Two thousand four hundred and sixty two consecutive subjects undergoing USGIs were included. Statistical analysis used to determine the rate of the overall VVR in USGIs and to determine if site of the injection or joint injected has an effect on this rate as well as age and gender effect.

RESULTS

Overall rate of VVR was 2.3% with shoulder and small joints of the hands and feet are more commonly affected than other sites. Females and patients aged younger than 65 years may be subjected to higher rate of VVR.

CONCLUSIONS

VVR has an overall low occurrence in USGI. The higher rate of VVR for shoulder and small joints of hands and feet procedures. Care should be taken when positioning a patient prior to the procedure to allow for a VVR in case it happens. VVR are more likely to occur in females and less likely in age more than 65 years.

The Haleem-Marks-Botchu classification: a novel CT-based classification for intracanal rib head penetration

PURPOSE

Intracanal rib head penetration is a well-known entity in dystrophic scoliotic curves in neurofibromatosis type 1. There is potential for spinal cord injury if this is not recognised and managed appropriately. No current CT-based classification system is currently in use to quantify rib head penetration. This article aims to propose and evaluate a novel CT-based classification for rib head penetration primarily for neurofibromatosis but which can also be utilised in other conditions of rib head penetration.

MATERIALS AND METHODS

The grading was developed as four grades: normal rib head (RH) position-Grade 0, subluxed extracanal RH position-Grade 1, RH at pedicle-Grade 2, intracanal RH-Grade 3. Grade 3 was further classified depending on the head position in the canal divided into thirds. Rib head penetration into proximal third (from ipsilateral side)-Grade 3A, into the middle third-Grade 3B and into the distal third-Grade 3C. Seventy-five axial CT images of Neurofibromatosis Type 1 patients in the paediatric age group were reviewed by a radiologist and a spinal surgeon independently to assess interobserver and intraobserver agreement of the novel CT classification. Agreement analysis was performed using the weighted Kappa statistic.

RESULTS

There was substantial interobserver correlation with mean Kappa score (k = 0.8, 95% CI 0.7-0.9) and near perfect intraobserver Kappa of 1.0 (95% CI 0.9-1.0) and 0.9 (95% CI 0.9-1.0) for the two readers.

CONCLUSION

The novel CT-based classification quantifies rib head penetration which aids in management planning.

Tumors of the Acromion Process—A Pictorial Review

Introduction  Acromion is essential for stabilizing the shoulder complex. Tumors of the acromion are rare. We report the largest series of acromion tumor and tumor-like lesion.

Materials and Methods  A retrospective review of the oncology and radiology database within our tertiary center for orthopaedic oncology was performed to identify all tumors of the acromion over the past 30 years and imaging was reviewed.

Results  We identified a total of 31 lesions arising in the acromion and chondrosarcoma was the commonest.

Conclusion  One needs to be aware of tumor and tumor-like lesions of acromion.

A guide to assessing post-operative complications following en bloc spinal resection

En-bloc resection of spinal tumours is a complex procedure with significant morbidity and mortality. The extensive resection leaves a large soft tissue and osseous defect requiring reconstruction. Following en-bloc resection, there may be complications relating to both the removal of the tumour and the subsequent reconstruction. This paper outlines the imaging appearances of the frequently encountered complications in our experience. The primary aim is to improve the confidence of the radiologist when reporting imaging following spinal en-bloc resection, however we believe this is also useful for the spinal and orthopaedic surgeons in assessing the patients following en block resection.

Current progress and future trends in imaging of musculoskeletal bone tumours

Plain radiographs and MRI remains the gold standard imaging modality for bone tumour and tumour like lesions. Several imaging techniques have been developed to be used in conjunction, but doubt remains over how much additional diagnostic information they provide over and above routine MRI bone tumour sequences. Given the plethora of new modalities, this review aims to highlight some of them and how they may help in the diagnostic assessment of musculoskeletal bone tumours.

Birmingham Intervention Tent Technique (BITT): A Technical Note

Objective We describe a novel and safe CT biopsy technique that we have termed the “Birmingham intervention tent technique (BITT).” This technique is ideal for biopsying osseous lesions where a direct approach is not possible due to difficult positioning.

Methods The BITT uses a plastic surgical forceps clamp attached at an angle to the biopsy needle, creating a tent shape. The finger rings of the forceps is stabilized on the table.

Results In our institution, we have already used the BITT successfully in over 10 cases.

Conclusion The BITT is an inexpensive and reproducible technique.

Iyengar-Botchu (IB) confluence of the medial knee- anatomy and clinico-radiological review

The Iyengar-Botchu confluence is a quadrilateral space on the medial side of the knee. Due to the presence of unique anatomical structures, this region is prone to injuries. The aim of this pictorial review is to illustrate an anatomical description of the structures, which form the IB complex confluence. Clinico-pathological correlation of common conditions associated with these structures will increase awareness of injuries in this area. A complementary imaging guidance will support clinical diagnosis and appropriate patient management.

Comparison between conventional CT and grayscale inversion CT images in the assessment of the post-operative spinal orthopaedic implants

AIM

To compare the accuracy of the inverted greyscale CT versus the conventional CT in the assessment of post-operative spinal orthopaedic implants and osseous fusion.

METHODS

50 patients who had CT as part of their routine spinal implant follow up were evaluated for the presence of fusion, fracture and loosening with conventional CT and with greyscale inverted CT images. 3 independent observers assessed the images 2 months apart. Diagnostic performance (sensitivity and specificity) of the conventional and greyscale inversion images relative to the reference standard were calculated. Agreement with the reference standard was assessed using Cohen's kappa for conventional and greyscale inversion images.

RESULTS

Correct classifications increased when using the greyscale inverted CT images for each reader compared to conventional CT images (40-46, 39 to 42 and 41 to 44 (out of 50)). Inverted images demonstrated better agreement with the reference standard than conventional grayscale images for assessment of fusion (kappa of 0.588 for inverted CT versus 0.484 for conventional CT) and loosening (kappa 0.386 for inverted versus 0.293 for conventional). Sensitivity was increased for assessment of fusion and loosening. McNemar's test performed for assessment of sensitivity differences showed statistical significance (p = 0.038 for fusion and p = 0.0313 for loosening).

CONCLUSION

Greyscale inversion CT is a useful adjunct which has advantages (improved sensitivity and better agreement) over conventional CT imaging in cases of fusion and loosening of metallic implants following spinal instrumentation. We recommend the use of both the greyscale inversion CT images and conventional CT imaging when assessing post-operative spinal orthopaedic implants.

The incidence and management of Isolated Greater Trochanteric Fractures - A systematic review of 166 cases

BACKGROUND

Isolated fractures of the greater trochanter are unusual injuries with a wide spectrum of presentation, investigations and management strategies.

AIMS

The objective of this study was to evaluate the incidence and treatment protocols used in the management of Isolated Greater Trochanteric Fractures (IGTF).

METHODS

A systematic literature review of the PubMed and Central Register of Controlled Trials (Cochrane) databases by using the search term 'greater trochanter fracture and hip fracture' was conducted for Randomised Controlled Trials (RCT's), including prospective and retrospective non-experimental studies.

RESULTS

The search yielded 15 studies meeting our inclusion criteria encompassing 166 patients with Isolated Greater Trochanteric Fractures (IGTF). Most of the reports were observational studies due to paucity of coverage on this topic in literature. Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) were the common modalities used to diagnose these injuries. Most of the patients were managed with non-operative methods.

CONCLUSION

This systematic review analyses the consensus of treatment of IGTF based on evidence-based practice. When the IGTF is identified, the majority of studies advocate conservative management to surgery for such cases. Furthermore, large cohort studies with clearly documented outcome follow up are required to establish objective treatment guidelines for IGTF.

Myositis ossificans revisited - The largest reported case series

INTRODUCTION

Myositis ossificans (MO) is a condition characterised by the formation of non-neoplastic heterotropic ossification in extraskeletal soft tissues.

MATERIAL AND METHODS

We performed a retrospective study of our radiology databases within our tertiary orthopaedic centre to identify all cases of MO, reported on X ray, Magnetic resonance imaging (MRI) and Computed tomography (CT) over the past 13 years (2007-2020).

RESULTS

We identified 68 cases of MO, which were included into our cohort. The average age of our patients was 36 years (range 4-84 years). 73% of cases (n = 50) were found to affect the lower limb muscles with the majority in the quadriceps.

CONCLUSION

We report the largest case series of MO and discuss the demographics, diagnoses and management.

Spinal collision lesions

Collision lesions are rare neoplasms often described in the hepatobiliary system, genitourinary system and adrenal glands. Vertebral haemangiomas (VH) are the most common lesions involving the vertebral bodies. VHs are usually asymptomatic and considered as "Do not touch" lesions. Rarely they can be symptomatic. Imaging findings of typical and atypical haemangiomas, variant forms of haemangioma such as aggressive haemangiomas are well known. Collision lesions involving VHs are extremely rare. This article presents a series of cases with collision lesions of the vertebral body involving VHs.

ADVANCES IN KNOWLEDGE

This Case series demonstrates the various collision lesions in spinal haemangioma.

The value of chest and skeletal staging in parosteal osteosarcoma: two-centre experience and literature review

OBJECTIVE

To determine the value of chest and skeletal staging in patients with parosteal osteosarcoma (POS), and the incidence of late local and chest recurrence.

MATERIALS AND METHODS

Retrospective review of patients across two institutions with histological confirmation of POS diagnosed between January 2007 and March 2020. Data collected included age, sex, skeletal location, results of chest CT and whole-body bone scintigraphy (WB-BSc) or whole-body MRI (WB-MRI) obtained at initial diagnosis. The histological tumour grade based on surgical resection specimens was classified as low-grade POS (LG-POS) and dedifferentiated POS (DD-POS). Findings of chest CT and skeletal staging were correlated with tumour grade. Follow-up chest CT and MRI studies were reviewed to determine the rate of late lung metastases and local recurrence.

RESULTS

There were 27 males and 44 females, mean age 33 years (range 12-79 years). The femur (n = 43) and tibia (n = 14) were the most commonly involved bones. From surgical resection histology, 42 (59.2%) were LG-POS and 29 (40.8%) were DD-POS. WB-BSc/WB-MRI showed no skeletal metastases, while 1 case of DD-POS presented with bilateral calcified lung metastases. At follow-up, 7 patients (9.9%) developed lung metastases (mean of 18.9 months, range 10-48 months) from initial presentation, of which all were DD-POS. All but 1 patient who developed subsequent lung metastases had a local recurrence.

CONCLUSIONS

Skeletal staging is unlikely to be of value in POS. Staging chest CT is very unlikely to demonstrate lung metastases in LG-POS and could be limited to DD-POS, particularly at the time of local recurrence.

Indeterminate pulmonary nodules are not associated with worse overall survival in Ewing Sarcoma

AIM

Lung metastases are a negative prognostic factor in Ewing sarcoma, however, the incidence and significance of sub-centimetre pulmonary nodules at diagnosis is unclear. The aims of this study were to (1): determine the incidence of indeterminate pulmonary nodules (IPNs) in patients diagnosed with Ewing sarcoma (2); establish the impact of IPNs on overall and metastasis-free survival and (3) identify patient, oncological and radiological factors that correlate with poorer prognosis in patients that present with IPNs on their staging chest CT.

MATERIALS & METHODS

Between 2008 and 2016, 173 patients with a first presentation of Ewing sarcoma of bone were retrospectively identified from an institutional database. Staging and follow-up chest CTs for all patients with IPN were reviewed by a senior radiologist. Clinical and radiologic course were examined to determine overall- and metastasis-free survival for IPN patients and to identify demographic, oncological or nodule-specific features that predict which IPN represent true lung metastases.

RESULTS

Following radiologic re-review, IPN were found in 8.7% of patients. Overall survival for IPN patients was comparable to those with a normal staging chest CT (2-year overall survival of 73.3% [95% CI 43.6-89] and 89.4% [95% CI 81.6-94], respectively; p = 0.34) and was significantly better than for patients with clear metastases (46.0% [95% CI 31.9-59]; p < 0.0001). Similarly, there was no difference in metastasis-free survival between 'No Metastases' and 'IPN' patients (p = 0.16). Lung metastases developed in 40% of IPN patients at a median 9.6 months. Reduction of nodule size on neoadjuvant chemotherapy was associated with worse overall survival in IPN patients (p = 0.0084).

CONCLUSION

IPN are not uncommon in patients diagnosed with Ewing sarcoma. In this study, we were unable to detect a difference in overall- or metastasis-free survival between patients with IPN at diagnosis and patients with normal staging chest CTs.