"Do-not-touch" lesions of bone revisited.

Incidental bone lesions are encountered frequently in day-to-day practice. Many of these lesions are indeterminate requiring referral to specialist centres for further characterisation with or without biopsy; however, as biopsy has its own drawbacks, not all lesions can be subjected to biopsy. The primary role of a radiologist in these situations is to characterise these lesions based on their imaging appearances into aggressive lesions requiring biopsy and non-aggressive lesions that do not require a biopsy. The term "do-not-touch lesion" is used to describe a lesion with typical radiographic appearances that can be characterised based on radiographic appearances alone without needing a biopsy. With recent advances in imaging, many incidental lesions can be characterised into do-not-touch lesions based on their imaging appearances alone using a single imaging technique or using a combination of imaging techniques and, less frequently, with the additional help of serological investigations, without the need for biopsy. Hence, the definition of do-not-touch lesions of bone needs a revisit. In this article, we attempt to redefine do-not-touch lesions of bone and propose an imaging-based classification for characterisation of these lesions.

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.

Tibial tuberosity lesions.

Lesions of the tibial tuberosity are very rare but often present a diagnostic dilemma due to their unusual location and appearances. Although some pathologies affecting this region are commonly seen elsewhere in the skeleton, they may have atypical imaging appearances and morphological characteristics when present at the tibial tuberosity. The present review describes the developmental stages of the tibial tuberosity, explaining why this area is prone to degenerative tractional changes and injury, and also highlights various pathologies including benign and malignant osseous lesions and trauma/degenerative related abnormalities.

The Haleem-Botchu classification: a novel CT-based classification for lumbar foraminal stenosis.

PURPOSE: No clinical CT-based classification system is currently in use for lumbar foraminal stenosis. MRI scanners are not easily available, are expensive and may be contraindicated in an increasing number of patients. This study aimed to propose and evaluate the reproducibility of a novel CT-based classification for lumbar foraminal stenosis. MATERIALS AND METHODS: The grading was developed as four grades: normal foramen-Grade 0, anteroposterior (AP)/superoinferior (SI) (single plane) fat compression-Grade 1, both AP/SI compression (two planes) without distortion of nerve root-Grade 2 and Grade 2 with distortion of nerve root-Grade 3. A total of 800 lumbar foramen of a cohort of 100 random patients over the age of 60 who had undergone both CT and MRI scans were reviewed by two radiologists independently to assess agreement of the novel CT classification against the MRI-based grading system of Lee et al. Interobserver(n = 400) and intraobserver agreement(n = 160) was also evaluated. Agreement analysis was performed using the weighted kappa statistic. RESULTS: A total of 100 patients (M:F = 45:55) with a mean age of 68.5 years (range 60-83 years were included in the study. The duration between CT and MRI scans was 98 days (range 0-540, SD-108). There was good correlation between CT and MRI with kappa scores (k = 0.81) and intraobserver kappa of 0.89 and 0.98 for the two readers. CONCLUSION: The novel CT-based classification correlates well with the MRI grading system and can safely and accurately replace it where required.

An imaging protocol for the management of central cartilage tumours of the proximal fibula.

AIM: To retrospectively review a series of solitary central cartilage tumours (CCTs) of the proximal fibula and propose an imaging protocol for their management. MATERIALS AND METHODS: Over 11 years, 48 patients were identified with a CCT of the proximal fibula. The initial magnetic resonance imaging (MRI) and follow-up imaging were assessed for tumour length, endosteal scalloping, or aggressive/malignant features. Each case was categorised according to the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP). The final diagnosis and outcome were reviewed to establish an appropriate imaging protocol for the management of similar cases in the future. RESULTS: The final diagnosis based on imaging alone or imaging and histopathology was enchondroma in 46 cases (96%) and atypical cartilage tumour (ACT)/low-grade chondrosarcoma in two (4%). Using the BACTIP classification, the majority were type IC (48%) with type IA the second commonest (24%). Of 19 that underwent follow-up MRI, only two revealed any increase in length, neither of which was shown to be malignant. No cases re-presented later with evidence of malignant transformation. CONCLUSION: There has been a significant increase in the number of CCTs of the proximal fibula referred to Royal Orthopaedic Hospital, Birmingham, over the past decade. This can largely be attributed to the increased use of MRI. The majority were benign with only 4% classified as an ACT. A modified BACTIP, the Fibular Atypical Cartilage Tumour Imaging Protocol (FACTIP) is presented, indicating which cases would benefit from follow-up imaging and which require referral to a specialist orthopaedic oncology service.

MRI assessment of anatomy and pathology of the iliofemoral ligament.

The iliofemoral ligament is strongest ligament of the body. We review the magnetic resonance imaging (MRI) appearances of the iliofemoral ligament, and discuss the disease entities that may affect this region.

Standard operating procedure of image-guided intervention during the COVID-19 pandemic: a combined tertiary musculoskeletal oncology centre experience.

AIM: To evaluate the response measures in continuing an image-guided intervention service in two tertiary-level musculoskeletal oncology centres during the COVID-19 pandemic. MATERIALS AND METHODS: This study was a retrospective review of all patients undergoing image-guided intervention in the computed tomography (CT) and normal ultrasound (US) rooms from 24 March 2020 to 24 May 2020 (during the COVID-19 pandemic peak) at Royal National Orthopaedic Hospital, London, and Royal Orthopaedic Hospital, Birmingham, UK. Measures were put in place to address air pressures, airflow direction, aerosol generation, and the safe utilisation of existing scanning rooms and work lists for interventional procedures. RESULTS: Three hundred and thirty-one patients (164 at Royal National Orthopaedic Hospital and 167 at Royal Orthopaedic Hospital) underwent image-guided procedures at both sites in the CT and US rooms. At the Royal National Orthopaedic Hospital, 40% of all procedures were performed under general anaesthesia. These consisted of 47 CT biopsies, 7 CT radiofrequency ablations (RFAs), and 12 US biopsies. At the Royal Orthopaedic Hospital, 86% of all procedures were performed under local anaesthetic, with no general anaesthetic procedures. These consisted of 61 CT biopsies and 83 US biopsies. All 256 patients having procedures in the CT room had no post-procedural complications or COVID-19-related symptoms and morbidity on follow-up. CONCLUSION: By adopting a pragmatic approach with meticulous planning, a limited, but fully functional image-guided interventional list can be run without any adverse patient outcomes.

Direct MR arthrography of the shoulder: current practice in the UK.

There is wide variation in the technique and type of contrast used for MR arthrography of shoulder. In this article, we discuss the current practice in UK and the reason for the change over the last few years.

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.

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.

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 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.

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.

Iliotibial band enthesopathy: an unusual cause of lateral knee pain post total knee replacement.

Iliotibial band (ITB) pathology is one of the main causes of lateral knee pain. The enthesopathy of the ITB at its insertion post total knee replacement (TKR) is a rare cause of lateral knee pain. We describe a series of cases of ITB enthesopathy with sonographic findings and management.

Alteration of patellar tendon morphology in patellofemoral instability (trochlear dysplasia).

INTRODUCTION: Trochlear Dysplasia (TD) is a condition that is characterized by the presence of an abnormally shaped trochlear groove, which hinders the patellofemoral joint (PFJ) stability. PFJ stability is determined by static and dynamic structures around the knee joint. We analysed whether the patellar tendon morphology is altered in patients with patellofemoral instability in Trochlear Dysplasia (TD). MATERIAL AND METHODS: Magnetic Resonance Imaging (MRI) studies for 50 consecutive knees with TD and 50 consecutive knees with normal PFJ morphology were obtained for evaluation. For each MRI study, the cross-sectional area (CSA) of the medial and lateral components of the patellar tendon was measured and used to calculate the cross-sectional area ratio (CSAR) by two readers. RESULTS: There was a statistically significant difference in the CSAR of the lateral-to-medial components of the patellar tendon between knees with normal PFJ morphology and knees with TD (one way ANOVA, F (4,95) = 7.743, p < 0.001). Pairwise comparisons amongst the Dejour subtypes of TD, revealed a statistically significance difference (p < 0.05) in the CSAR ratio between patients with normal PFJ morphology, and patients with type A (p = 0.007) and type C, TD. There was moderate correlation between the readers on Intraclass Correlation Coefficient (ICC) analysis (ICC- 0.7). CONCLUSION: Our findings reveals hypertrophy of the medial part of the patellar tendon in patients with PFJ instability and TD. These differences could reflect the dynamic compensatory changes occurring at the PFJ to counteract the laterally directed instability vectors found in this condition.

Ultrasound of glenoid labrum with MR arthrographic correlation.

Ultrasound (US) is a reliable non-invasive method to image the rotator cuff tendons. Even though glenoid labral pathology is common, it is not routinely looked at as part of the shoulder ultrasound protocol. Currently, the gold standard for labral imaging remains MR arthrography. However, given the rather long waiting list and cost implications, US may be used as a modality to quickly screen the shoulder for gross labral pathology. Whilst there is relative paucity of the literature outlining labral pathology on US, there is none correlating sonographic and corresponding MRI appearances. We present a pictorial review highlighting scanning positioning, US and corresponding MRI appearances of a normal labrum and various labral pathologies. We discuss useful scanning tips and characteristic US signs which can help the radiologist.

Power Doppler in musculoskeletal ultrasound: uses, pitfalls and principles to overcome its shortcomings.

Power Doppler (PD) is used widely in musculoskeletal ultrasound, especially in the assessment of structures for evidence of inflammation and in evaluating soft tissue neoplasms. We reinforce and delineate the three cardinal principles of optimising PD assessment in order to avoid false positive or false negative results; namely (1) Optimal gain settings (2) Adequate transducer pressure, and (3) Proper patient/anatomical structure-of-interest positioning with complete tissue relaxation.

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.