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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.

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.

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. 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. 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. The novel CT-based classification correlates well with the MRI grading system and can safely and accurately replace it where required.

Success in the management of bone sarcomas entails being able to achieve wide margins, which helps decrease the risk of local recurrence and provide an improvement in overall survival. The role of computer-assisted surgery has been investigated across various areas of orthopaedics, including joint replacement, cruciate ligament reconstruction, and pedicle screw placements which has led to increased interested in computer assisted tumour surgery (CATS). CATS can be used in a wide array of tumour surgeries, however its role in pelvic and sacral tumours is unparalled. Its importance lies in being able to provide radiological information to guide the surgeon at the time of surgery i.e. the distance from the tumour to the resection margin can be determined precisely based on preoperative planning and intra-operative image guidance. This minimises unnecessary bone resection, aiming to achieve good oncological and functional results which can be challenging in pelvic surgery. Most published articles on CATS have concentrated on the surgical aspects of navigation surgery. Although advanced imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) scans can provide anatomic detail about the primary tumour, the successful transfer of that information from a viewing screen to the intraoperative field can be difficult. The role of the radiologist lies in being able to provide appropriate imaging (CT, MRI) to facilitate surgical planning. This article aims at providing the radiologist a surgical insight on CATS and to facilitate optimal imaging in a patient tentatively being planned for CATS.

OBJECTIVE: Degenerative thoracic stenosis has been shown to most frequently involve the lower thoracic segments (T9-T12) where there is greater mobility and vulnerability due to flexion, extension and rotation of the spine. The thoracolumbar junction is considered anatomically to be T12-L1; the anatomical transition between the relatively immobile thoracic spine and relatively mobile lumbar spine. From anecdotal experience at our institution, we hypothesise that the true thoracolumbar junction is higher, at T10-11; the point of transition from floating to false ribs resulting in increased mobility at T10-11. METHODS AND MATERIALS: A retrospective review was performed of MRI lumbar and whole spine performed on patients aged 10–40 years in our institution over a 5-year period. Patients with previous surgery, chronic spinal disorders and congenital abnormalities were excluded from the study. Intervertebral discs from T8-9 to L1-2 were assessed for evidence of degeneration using the Pfirrmann grading system. Data obtained from a study using computer-based models to assess mean resultant loads in flexion, sitting and standing from T8-9 to L1-2 on patients aged 18–35 years was also analysed. The mean load gradients between two consecutive discs from T8 to L2 were analysed. Statistical analysis was performed with SPSS (p

Objective Cervical spine osteochondromas are rare with approximately 3% of solitary and 7–9% of hereditary osteochondromas occurring in the spine. Almost 50% of spinal osteochondromas occur in the cervical region. Methods A search of osteochondroma of cervical spine was performed of our radiology database. Results In this study, we present 11 cases of adult cervical spine osteochondromas. These predominantly involved the posterior elements. The cartilage cap was more than 2 cm in 2 cases. There was cord compression in 1 case, foraminal narrowing in 2 patients and vertebral artery compression in 1 case. 6 patients underwent excision with majority being osteochondroma. There was only one case of chondrosarcoma. Conclusion Osteochondromas of cervical spine and extremely rare and symptomatology are due to mass effect. One should be aware of this entitly when analysing cervical spine for neck pain or lump.

Studies have demonstrated the presence of muscle atrophy around the hip in patients with hip osteoarthritis. Few studies have examined the psoas muscle or assessed it at a paraspinal level in patients post-total hip arthroplasty. The aim of this study was to determine if there is significant psoas muscle atrophy as indicated by muscle cross-sectional area and high degree of fat infiltration post-unilateral hip arthroplasty. Retrospective analysis of 341 patients with unilateral hip implant and subsequent lumbar spine MRI over a 8-year period was performed. Fat infiltration and cross-sectional area of the psoas muscle at L3/4 level were measured by two musculoskeletal fellows (1 year experience in musculoskeletal radiology), and comparison made between the implant and non-operative sides was made. Fat infiltration was measured using the modified Goutallier grading. The degree of hip osteoarthritis in the non-operative side was measured using the Kellgren-Lawrence grading. The data was analysed using paired t test, ANOVA, unpaired t test, Pearson correlation and Jonckheere-Terpstra test. The cross-sectional area of the psoas muscle on the implant side was significantly less than the non-operative side. There was significance between the cross-sectional area difference and the fat grade of the implant side. Our results demonstrate psoas atrophy on the implant side compared to the non-operative side in post-unilateral implant patients. Post-operative hip implant rehabilitation may benefit from more focused psoas strengthening exercises to improve functional outcome.

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.

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.

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.

Introduction The posterior compartment of the thigh is composed of three major muscles collectively known as the hamstring muscles. These consist of the biceps femoris short and long head, semimembranosus and semitendinosus. Excluding the short head of biceps femoris, the hamstrings contribute to the movement of the hip and the knee joints as they span across both joints. Our hypothesis is that the nature of the conjoint tendon -ischial angle predisposes to an increased risk of tearing in this hamstring component. We therefore aim to look at the anatomy of the hamstring origin at the ischial tuberosity and spatial relationship between the long head of biceps, semitendinosus and semimembranosus in the form of vector angles. Material and methods 100 consecutive pelvic MRIs in patients under the age of 40 years were reviewed by musculoskeletal radiology fellow and a consultant musculoskeletal radiologist with more than 10 years’ experience in musculoskeletal radiology and measured the angle of origin of conjoined tendon and semimembranosus at its ischial origin. P value using a paired t-test was less than 0.0001 confirming that the difference in the vector angle of the different hamstring components was statistically significant. Results The median angle of origin of conjoined tendon was 12° and for semimembranosus was 6°. Applying the concept of Newton’s second law to the angles calculated we demonstrated that an increase of 9% force applied to the conjoint tendon origin when compared to the semimembranosus tendon. Conclusion We hypothesis that the difference in the angle of origin of the components of hamstrings might be one of the reasons for the difference in the incidence and patterns of the injuries of the various muscles of the hamstrings.

Purpose To evaluate the correlation between trochlear dysplasia and acetabular coverage. Materials and methods 109 retrospective CT studies referred from the young adult knee clinic were independently reviewed by two observers. Anterior acetabular (AASA) and posterior acetabular (PASA) sector angles were calculated bilaterally on axial CT. Trochlear dysplasia was graded using the Dejour classification (A-D). ANOVA test was used. Results Dejour types A, B and D trochlear dysplasia were associated with a significantly increased AASA (P value = 0.0011). Conclusion Our results demonstrate a significant relationship between trochlear dysplasia and anterior acetabular coverage, as measured by AASA.

AIM To validate an imaging protocol for the management of solitary central cartilage tumours (CCTs) of the proximal humerus and around the knee. MATERIALS AND METHODS Over a 10-year period, 387 patients were identified with a CCT in the proximal humerus, distal femur, and proximal tibia, who were referred to a single unit either from primary/secondary care or tertiary care directly to Royal Orthopaedic Hospital, a specialist orthopaedic oncology service. The initial magnetic resonance imaging (MRI) images and any follow-up images were evaluated for length of tumour, presence/absence of endosteal scalloping, or aggressive/malignant features. The cases were categorised into one of seven types according to the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP). The outcome in the cases was assessed to ascertain if application of the protocol would have led to any delay in the diagnosis of malignant transformation to a chondrosarcoma. RESULTS The incidence of malignancy (chondrosarcoma) increased with ascending BACTIP. There was a 100% benign diagnosis (enchondroma) in types IA and IB, 96% in IIA, and 83% in IIB. Fifty-seven percent of type IIC and 97% type III were diagnosed as malignant. In only one case would the application of the protocol have led to a 5-month delay in the diagnosis of chondrosarcoma. CONCLUSIONS This retrospective study confirms the BACTIP as a useful tool for the general radiologist in the initial assessment of CCT in the proximal humerus and around the knee with the exception of the proximal fibula. In particular, determining which cases need prompt referral to a specialist orthopaedic oncology service for further assessment.

Groin pain can be caused by a myriad of pathologies. Abnormalities of the rectus femoris are a very rare cause of groin pain; calcific tendinopathy of the direct head is particularly so, with only two case reports in the literature. We report the first case of calcific tendinopathy of the direct head of the rectus femoris that was treated effectively with ultrasound-guided percutaneous irrigation of calcific tendinopathy (USPICT). The anatomy of the rectus femoris and the technique for US-PICT of the rectus femoris are also described.

INTRODUCTION: An intra-neural ganglion cyst of the lateral dorsal cutaneous branch of the sural nerve is rare, with only a few cases reported in the literature. MATERIALS AND METHODS: We carried out a retrospective investigation of patients with an intraneural ganglion cyst of the lateral dorsal cutaneous nerve. RESULTS: We present a case series of four patients with intra-neural ganglion cysts of the lateral dorsal cutaneous nerve, the distal continuation of the sural nerve at the lateral aspect of the foot. CONCLUSION: Intra-neural ganglion cysts of the lateral dorsal cutaneous nerve are rare. They represent a relatively uncommon source of lateral ankle pain, which can easily be diagnosed with ultrasound (US) and magnetic resonance imaging and managed effectively with US-guided aspiration or surgical excision.

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.

Introduction MR and CT are excellent complimentary diagnostic modalities for evaluation of hip pain which are often used together along with radiographs. However, CT involves radiation, which is a concern particularly in younger patients. T1VIBE is a 3D gradient echo MR sequence with high intrinsic contrast between the bone and soft tissues with multiplanar capabilities. Aim We performed a study to assess if TIVIBE can be used to complement MR for evaluation of hip pain in young adults and to see if measurements and angles can be calculated using T1VIBE inversion images with similar accuracy to CT scan. Material and methods A retrospective review of 50 patients aged less than 40 years, who had MR (including TIVIBE) and CT of pelvis was performed. Post surgical patients were excluded. Some important measurements such as Centre edge angle, Tonnis’ angle, anterior acetabular sector angle, posterior acetabular sector angle and acetabular version were independently measured by two readers on T1 VIBE inversion and CT images separately and measurements were compared. One reader performed the measurements again to assess for intra-observer error. Results There was a female predominance (37 F, 13M) with an average age of 27.6 years (range of 17–39). There was no significant difference in the measurements between CT and TI VIBE inversion and there was good intra and interobservor reliability. Conclusion TI VIBE inversion sequence can be used as an alternative to CT with added advantage of alleviating the radiation exposure.

Numerous corticosteroid preparations are available, but the type and dose administered is frequently at the discretion of the clinician. This is often based on anecdotal evidence and experience rather than formal clinical guidelines. In order to better understand current practice, we anonymously surveyed 100 members of the British Society of Skeletal Radiologists. The results of the survey demonstrated the arbitrary use of all types of steroid preparation at different anatomical locations. In this article, we review the commonly used corticosteroids and propose a guideline to help practitioners decide on the type and dose of steroid depending on the treatment location.

Facet joints are the only synovial joints in the spine and can be involved in a large number of pathological processes including arthropathy, infection, inflammation, trauma and tumour. In this review article, we present a spectrum of pathologies that arise from or involve facet joints that we have encountered in our tertiary orthopaedic and spinal centre. The objective of this review is to create an aide memoire for the general radiologist who may encounter facet joint pathology, which they may not be familiar with.

Arthroscopic labral repair is a frequently performed procedure for symptomatic labral tears. Recurrent pain postoperatively may be due to the failure of the repair or anchor detachment. We report the imaging features of a displaced anchor with arthroscopic correlation.

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.

Magnetic resonance imaging (MRI) is the established technique for evaluating the spine. Unfortunately, the supine position of the patient during conventional MRI scanning does not truly reflect the physiological forces experienced by the discoligamentous structures during normal upright posture and ambulation. Upright MRI is a relatively new technique that allows the patient to be scanned in several different weight-bearing positions, which may potentially demonstrate occult pathology not visualised in the supine position. The imaging technique and current clinical indications of upright spinal MRI would be discussed.

There is a myriad of potential mass lesions that occur in the popliteal fossa, which present as palpable masses or are found incidentally on imaging. With a thorough knowledge and understanding of the appearances and locations of these different entities, one can narrow the differential diagnoses in the majority of cases. This will eliminate unnecessary additional investigations and enable a more rapid management. We present a review of frequently encountered and less common entities using an anatomical sieve, with the aim of providing a diagnostic approach to popliteal fossa masses.

BACKGROUND: Mucoid degeneration (MD) of the anterior cruciate ligament (ACL) are a well-known pathological entity. We have encountered several patients with MD of the ACL, found to have a anterior translation of tibia a exceeding 5 mm with an intact ACL. We studied this cohort and investigated the likely cause of this. METHODS: A retrospective search of our department's radiology system to identify all patients referred from the knee orthopaedic clinic for MR imaging over a span of 10 years. All patients had MD within the substance of the ACL and an intact ACL. We evaluated the degree of anterior translation of the tibia (ATT) in relation to the femur in mucoid degeneration of ACL. RESULTS: We identified 464 consecutive cases. The mean age was 52 years. There was a male predominance of 261 to 203 female. The average PTF measurement was 2.4 mm with a range of 0-20mm. Of the 464 cases, 3 397 patients had an insignificant ATT of < 5 mm. (0mm. 67. 67 67 patients had a ATT >5 mm. Of them, 32.8% had a ATT of 6 mm, 53.7% had a ATT range between 7 and 9 mm, with the remaining 13.4% above 9 mm in length. CONCLUSION: It is essential to look for other secondary signs of ACL tears and not only focus on ATT as well as correlate this with clinical findings.

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.

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.

Radiological imaging is a routinely used diagnostic tool in the evaluation of the orthopedic patient. Imaging modalities including conventional radiography, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine (NM) are routinely used in the assessment of musculoskeletal abnormalities. The choice of imaging modality used should be tailored to the individual, but patient factors, the experience and expertise of the referring clinician and the radiologist, as well as the availability, safety, cost, and invasiveness of the technique should be considered. In this chapter, we review the basic physics of each imaging modality. The role of each modality as well as its advantages and limitations in the orthopedic setting will also be highlighted.

To investigate whether the long-held view that the hand is the commonest site for an enchondroma is actually correct in light of more sensitive imaging techniques that are able to demonstrate small enchondromas at other skeletal sites.A two-part retrospective study was undertaken. Part 1 comprised a review of the hand radiographs obtained in two major teaching hospitals over a 10-year period to establish the incidence of enchondroma in the hand. Part 2 was a review of a series of enchondromas of the proximal humerus, distal femur, and proximal tibia4 cm in length on magnetic resonance imaging (MRI) to see which cases were visible or not on corresponding radiographs.Part 1: 84 enchondromas were identified on 116,354 trauma radiographs to give an incidence of 0.07%. Part 2: 157 patients with an enchondroma on MRI4 cm were reviewed. Only 17% of lesions2 cm in length were visible on the contemporaneous radiographs. In lesions that were 2-2.9 and 3-3.9 cm the percentage visible on the radiographs increased to 58 and 77%, respectively.It is well recognised from existing studies that incidental enchondromas can be seen in approximately 2.5% of routine shoulder and knee MRI scans. This figure is 35 times higher than the incidence found in the series of hand trauma radiographs. This infers that the hand should no longer be considered as the commonest site for an enchondroma. This is because radiographs are relatively insensitive to the detection of small lesions in larger bones, such as the proximal humerus and around the knee, when compared with MRI.

AIM To provide a diagnostic approach to pulmonary nodules in patients with chondrosarcoma. MATERIALS AND METHODS A search of the oncology database at a specialist orthopaedic oncology referral centre was performed to identify all patients who were treated surgically for chondrosarcoma between January 2007 and December 2018. Reports from the computed tomography (CT) examinations of the thorax of these patients were reviewed. In patients who had pulmonary nodules/metastases identified on CT, data on the primary chondrosarcoma and pulmonary nodule characteristics were collected. RESULTS Twenty point two percent of patients had a pulmonary nodule identified on either initial or follow-up staging CT of the thorax, of which 8.1% were pulmonary metastases. Patients with grade 3 and dedifferentiated chondrosarcoma were more likely to have pulmonary metastases than patients with grade 1/2 chondrosarcoma. The time interval to developing metastases was shorter in patients with grade 2/3 and dedifferentiated chondrosarcoma versus patients with grade 1 chondrosarcoma. A low proportion of patients with grade 1 chondrosarcoma developed metastases (12.5%), all of which were identified at the time of a local recurrence. Nodules ≥10mm, nodules with lobulate margins, nodules containing irregular or subtle calcification, and nodules seen bilaterally or both centrally and peripherally were more likely to represent pulmonary metastases than benign nodules. CONCLUSION The diagnostic significance of pulmonary nodules (i.e., whether they represent pulmonary metastases or not) can be predicted by taking into account a number of factors, in particular, the histological grade of the patient's chondrosarcoma, the size and margins of the nodules, and the presence of subtle/irregular calcification.

We describe a novel and efficient CT biopsy technique that we have termed ‘skin adhesive and hand-aided biopsy technique’, shortened to the acronym SAHNA. This technique is ideal for biopsying surface osseous lesions where there is a lack of subcutaneous fat. This avoids the need for the radiologist’s hand to be in close proximity to the CT scanner beam at the time of intervention. The SAHNA technique uses a plastic surgical forceps towel clamp to stabilise the biopsy needle just proximal to the lesion after piercing through the skin. The clamp itself is stabilised via a self-adhesive dressing which is stuck down to the skin at its shank. In our institution, we have already used the SAHNA technique successfully in over 5 cases. The SAHNA technique is a widely accessible and effective way of stabilising the CT biopsy needle in technically challenging superficial bony lesions.

The ring-shaped meniscus (RSM) is a rare meniscal variant in which there is an intermeniscal bridge between the anterior and posterior horns of the meniscus, thus forming a complete ring. The lateral meniscus is more commonly involved than the medial meniscus. Distinguishing an RSM from a bucket handle tear (BHT) with a displaced fragment in the intercondylar notch is challenging and there are reports of negative arthroscopies for suspected BHTs. There are many reports of symptomatic and asymptomatic lateral RSMs diagnosed on MRI in the literature. We report a series of RSMs in six patients, which includes MRI descriptions of two cases of medial RSM and a case of bilateral lateral RSM, which were diagnosed on MRI and have never previously been reported. This study will also describe the various imaging features of a RSM that distinguish it from a displaced BHT. We will also discuss associated rare malformations encountered in our study, such as hypoplastic anterior cruciate ligament and the anomalous insertion of the popliteus tendon onto the posterior horn of a lateral RSM.

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.

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.

Aim To provide a diagnostic approach to distinguish osteochondroma-induced pseudoaneurysm from sarcoma on imaging and prevent biopsy which may be fatal. Materials and Methods A retrospective study of the orthopaedic oncology database was performed to identify all patients referred to specialist orthopaedic oncology service with a final diagnosis of osteochondroma-induced pseudoaneurysm. The demographics of the cohort, the anatomical location of the osteochondromas and pseudoaneurysms, and the imaging appearances were assessed. Results Seven contemporary and one historical case of osteochondroma-induced-pseudoaneurysm were identified. There were five patients with solitary osteochondroma and three cases of hereditary multiple exostosis. Five cases underwent magnetic resonance imaging (MRI) of which pulsation artefact was present in 40%. On MRI, all the present cases demonstrated a small central pseudoaneurysm surrounded by multiple eccentric layers of thrombus and haemorrhage, which was termed the “eccentric-whorl sign”. Conclusion Osteochondroma-induced pseudoaneurysms are often misdiagnosed as malignant transformation of an osteochondroma or a soft-tissue sarcoma and referred for urgent biopsy. This study presents the largest case series, which includes the first documented case diagnosed in 1934. Differentiating and characterising pseudoaneurysms from sarcomas is imperative in order to prevent a biopsy, which could be fatal.

We describe a novel and safe needle-holding method that we have termed the ‘dual steristrip technique’. This technique can be used to stabilize the bone biopsy needle without the need for the radiologist’s hand to be in close proximity to the X-ray beam during CT-guided intervention. The dual steristrip technique uses steristrips to stabilize the bone biopsy needle and allows for accurate assessment of needle position and trajectory. This involves affixing one end of a steristrip to the skin 2 cm from the needle skin entry point, wrapping the mid-section of the steristrip around the biopsy needle and affixing the other end of the steristrip to the skin at the opposite side of the needle 2 cm from the needle skin entry point. A second steristrip is then applied in a similar fashion at 90° to the first steristrip. In our institution, we have used the dual steristrip technique to stabilize the biopsy needle in certain cases where assessment of needle position/trajectory can be more challenging. This includes cases where there is a paucity of soft tissues overlying the bone or if the bone lesion is located in the superficial cortex. We have found it to be successful in 80% of cases. The dual steristrip technique is a safe and effective needle stabilization method that should be considered by the interventional radiologist in challenging CT-guided bone biopsy cases.

Antecubital pain can be caused by a myriad of pathologies. Abnormalities of the brachialis, in particular, tendinopathy at its insertion, are extremely rare, with no case report in the literature. We report the first case of tendinopathy of the brachialis tendon at its insertion in a 42-year-old male who presented with a year-long history of antecubital pain. The anatomy of the brachialis and the technique for ultrasound-guided steroid injection of the brachialis will also be described.

Primary bone tumours arising from the lesser trochanter (LT) are rare and the literature describing them is sparse. In this paper, we describe the largest series of LT tumours describing the demographics, diagnosis and management. Methods A retrospective search of prospectively maintained radiology and oncology databases was performed to identify bone tumours of the LT diagnosed between 2007 and 2018. Metastatic lesions were excluded. All cases were re-reviewed by a senior Radiologist and all case of isolated tumours of the LT were included. Results 23 cases of isolated LT tumours were identified. There were 15 males and 8 females. Mean age of our cohort was 32 (14–63) years. Most (n = 19, 82.6%) cases had classic radiological (Radiographic, MR Imaging and CT) features and therefore did not undergo biopsy. 4 patients had equivocal radiological investigations that required biopsy to confirm the diagnosis. MR imaging was the most commonly used imaging modality for diagnosis (n = 17, 73.9%) There was a broad range of tumour subtypes, and osteochondroma (n = 17, 73.9%) the most frequently diagnosed. Surgical excision was performed in 4 patients (all osteochondromas) and 4 patients underwent therapeutic radiological guided hip injections for symptomatic relief. The remaining cases were managed conservatively and where they were identified incidentally, no intervention was required. Conclusion We report the largest case series of isolated primary bone tumours of the LT. All isolated primary bone tumours of LT are benign. Osteochondroma is the most common. The diagnosis can be made with on radiological investigations in most patients.

Radiological imaging is an essential component of the routine evaluation of patients with musculoskeletal disorders. A variety of imaging modalities can be utilized to ensure that a correct diagnosis is reached, and the patient is put on an appropriate treatment path. In recent years, significant technological advances have been made in imaging and specific applications developed for assessing the orthopedic patient. These recent advances show promise in increasing our molecular, functional, and structural understanding of pathological processes in the musculoskeletal setting.

Central cartilage tumours of bone range from the benign enchondroma to the malignant chondrosarcoma. They are an incidental finding in up to 2.8% of routine magnetic resonance imaging (MRI) examinations performed of the shoulder and knee. The purpose of this review is to provide a current appraisal of the imaging and histological challenges of distinguishing enchondroma from low-grade chondrosarcoma. The general radiologist, encountering these lesions in the proximal humerus and around the knee, is introduced to the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP). This provides a guide to the initial assessment and diagnosis, a stepwise imaging follow-up plan, and the indications for onward specialist orthopaedic oncology referral or discharge from follow-up.

Aim To evaluate the frequency of the “flow-void” sign in a large series of pathologically proven renal cell carcinoma (RCC) bone metastases referred to a specialist unit and to evaluate its correlation with both lesion size and imaging sequence. A further aim was to describe a proposed grading system for the description of the “flow-void” sign. Materials and methods A retrospective review of patients with magnetic resonance imaging (MRI) of pathologically proven RCC bone metastases between September 2007 and December 2017 was performed. MRI images were reviewed for the presence of the “flow-void” sign and a proposed grading system for this sign was applied. Statistical analysis was performed to determine the association between the presence of the “flow-void” sign and lesion size and MRI sequence. Results One hundred and forty bone lesions in 123 patients with histologically proven metastatic RCC were reviewed. One hundred and thirty-two (94.3%) lesions demonstrated the “flow-void” sign on at least one sequence in each study. A statistically significant difference was demonstrated between lesion size and the presence and type of “flow-void” sign. Lesions demonstrating type 3 “flow-void” sign had mean dimensions of 82.2 mm compared to 47.3 mm for lesions that did not demonstrate the “flow-void” sign (χ2(2) =11.4; p=0.01). T2-weighted, proton density and fat-saturated imaging also demonstrated the “flow-void” sign more frequently. Conclusion The “flow-void” sign is a common imaging feature within RCC bone metastases. When observed, the “flow-void” sign can be a useful imaging feature in the diagnosis of RCC bone metastases.

Aim To present the imaging features of heterotopic ossification (HO) related to the radial tuberosity initially referred as a suspected sarcoma. Materials and methods Local institutional review board approval was obtained. A retrospective search of the oncology database was conducted to identify cases of ossification related to the radial tuberosity, referred to the supra-regional orthopaedic oncology centre as a suspected sarcoma. Furthermore, cases of soft-tissue sarcoma (STS) of the proximal forearm were also identified. The imaging findings were reviewed for all relevant cases. Results Over a 10-year period, 50 cases of STS of the forearm were identified with 23 involving the proximal forearm. STS was intimately related to the radial tuberosity in 52% (12/23) of these cases. There was no calcification or ossification related to the radial tuberosity in any of these sarcomas. During the same 10-year period, five cases of HO related to the radial tuberosity were identified. Demographics of these five cases revealed no significant sex predominance with a median age of 60 years. No obvious precipitating cause or predisposing condition was demonstrated. All five cases had radiographic evidence of ossification ranging from 20–53 mm in maximal dimension. Apart from one patient who had extensive ossification extending up the distal biceps tendon, the biceps tendon was otherwise normal on magnetic resonance imaging (MRI). There was only one case of mild osseous oedema of the proximal radius. Conclusion No STS adjacent to the radial tuberosity was associated with ossification related to the radial tuberosity. Ossification related to the radial tuberosity is a benign entity and radiologists need to be aware of this tumour mimic.

Soft tissue sarcomas are rare tumours which can be clinically difficult to differentiate from more common benign lesions. Imaging plays a fundamental role in diagnosis, but in some cases it can be difficult to differentiate benign from malignant conditions. This article reviews potential pitfalls in soft tissue sarcoma imaging.

Unfortunately, the legend of Fig. 5 was incorrectly published in original publication. The corrected legend is given below.