Tumours and tumour mimics in the olecranon.

Lesions in the olecranon are rare and may be identified during the investigation of a clinically suspected abnormality or as an incidental finding. This review describes the spectrum of tumours and tumour-like lesions that can involve the olecranon and illustrates the radiographic, CT, and MRI appearances that may facilitate diagnosis. A variety of pathological processes affecting the olecranon are presented and discussed including the epidemiology and imaging features.

The role of ultrasound in the assessment of post-operative complications following hip arthroplasty.

Hip arthroplasty is one of the most commonly performed orthopedic procedures. Clinicians can be faced with the diagnostic dilemma of the patient presenting with a painful hip following arthroplasty and satisfactory post-operative radiographs. Identifying the cause of symptoms can be challenging and ultrasound is increasingly being utilized in the evaluation of potential soft tissue complications following hip surgery. In this article, we describe the common surgical approaches used during hip arthroplasty as this can influence the nature and location of subsequent complications. A review of the literature is presented along with the imaging appearances frequently encountered when imaging this patient population.

Fatigue-type stress fractures of the lower limb associated with fibrous cortical defects/non-ossifying fibromas in the skeletally immature.

AIM: To investigate the association of a fatigue-type stress fracture and a fibrous cortical defect/non-ossifying fibroma (FCD/NOF) of the lower limb long bones in skeletally immature patients. MATERIALS AND METHODS: The patient database of a specialist orthopaedic oncology centre was searched to determine the number of skeletally immature patients (

Hip arthroplasty. Part 1: prosthesis terminology and classification.

Hip arthroplasty is an extremely common orthopaedic procedure and there is a wide array of implants that are in current use in the UK. The follow-up of patients who have undergone insertion of a hip prosthesis is shifting from a consultant-lead hospital service towards primary care. As this change in patient care continues it becomes increasingly important that an accurate description of the radiographic features is communicated to the primary-care practitioner so appropriate specialist input can be triggered. This review focuses on the terminology and classification of hip prostheses. This acts as a precursor for Part 2 of this series, which describes the normal and abnormal radiographic findings following hip prosthesis insertion.

Hip arthroplasty. Part 2: normal and abnormal radiographic findings.

This review addresses the normal and abnormal radiographic findings that can be encountered during the follow-up of patients with total hip arthroplasty (THA). The relative significance of different patterns of radiolucency, bone sclerosis, and component position is discussed. The normal or pathological significance of these findings is correlated with design, surface, and fixation of the prosthetic components. It is essential to have a good knowledge of expected and unexpected radiological evolution according to the different types of prostheses. This paper emphasizes the importance of serial studies compared with early postoperative radiographs during follow-up in order to report accurately any sign of prosthetic failure and trigger prompt specialist referral. Basic technical guidelines and schedule recommendations for radiological follow-up are summarized.

Giant cell tumour of the triquetrum.

We present details of a case of giant cell tumour of bone (GCTOB) involving the triquetrum. GCTOB arising within the carpus is exceedingly rare and, to our knowledge, this is only the second case of monostotic GCTOB of the triquetrum that has been reported.

Bone marrow oedema associated with benign and malignant bone tumours.

Bone marrow oedema is associated with a wide variety of pathological processes including both benign and malignant bone tumours. This imaging finding in relation to intraosseous tumours can aid in providing a more focused differential diagnosis. In this review, we will discuss the MR imaging of bone marrow oedema surrounding intraosseous neoplasms. The different pulse sequences used in differentiating underlying tumour from surrounding oedema are discussed along with the role of dynamic contrast enhanced MRI. Benign lesions commonly associated with bone marrow oedema include osteoid osteoma, osteoblastoma, chondroblastoma and Langerhan's cell histiocytosis. Metastases and malignant primary bone tumours such as osteosarcoma, Ewing's sarcoma and chondrosarcoma may also be surrounded by bone marrow oedema. The imaging findings of these conditions are reviewed and illustrated. Finally, the importance of bone marrow oedema in assessment of post chemotherapeutic response is addressed.

Imaging of infectious spinal disorders in children and adults.

The aim of this review article is to outline the imaging of infectious disorders of the spine in adults and children. The clinical presentation, potential routes of infection and the pathogens commonly identified are discussed. The value of different imaging modalities in the diagnosis of spinal infection is presented including radiographic, CT, MR imaging and Nuclear Medicine including PET. The use of image guided techniques for diagnosis and subsequent treatment is briefly covered. The major differential diagnoses of infectious disorders of the spine are identified and contrasted with the typical findings in infection. The use of follow up imaging is evaluated.

The utility of repeat ultrasound imaging in the follow-up of metal-on-metal hip arthroplasty patients.

INTRODUCTION: We assessed changes in metal-on-metal hip arthroplasties (MoMHAs) after repeat ultrasound examination. METHODS: This retrospective, single-centre cohort study involved all patients undergoing two ultrasound examinations of the same MoMHA. Between 2010 and 2014, 96 ultrasound examinations were performed in 48 MoMHAs (mean time between scans = 1.1 years). A radiologist assigned each scan to one of four grades and measured volumes of any solid/cystic masses. Changes in grade and lesion volume between scans were analysed. RESULTS: Change in grade between scans was significant (p=0.012); 27% (n=13) of MoMHAs increased in grade, 67% (n=32) had no grade change, and 6% (n=3) decreased in grade. The mean increase in lesion volume was 24.2cm(3) by the second scan, and was significant (p=0.023). Evidence of progression in findings was observed in 54% (26/48) of MoMHAs. Of patients with normal scans initially, 44% (8/18) developed abnormalities. No factors (including blood metal ion concentrations and cup position) were associated significantly with progression of ultrasound findings. CONCLUSIONS: Repeat ultrasound in MoMHA patients demonstrated that findings frequently progress in the short-term. Therefore, regular surveillance of MoMHA patients is important, with ultrasound representing an effective investigation for identifying the development and progression of lesions.

The role of multidetector CT arthrography in the investigation of suspected intra-articular hip pathology.

The aim of this study was to evaluate the role of multidetector CT (MDCT) arthrography in the diagnosis of intra-articular hip pathology. A retrospective review of 96 patients who had undergone CT hip arthrography was performed. Data regarding the presence of a labral tear, paralabral cyst, chondral loss, acetabular version, femoral morphology and fibrocystic change were collected. We detected 28 labral tears (24 anterior, 2 anterolateral, 1 lateral and 1 posterolateral). An abnormal labral-chondral transitional zone was seen in 9 patients and 4 patients had surface labral fraying. We identified three paralabral cysts. Acetabular cartilage loss was detected in 45 and femoral cartilage loss in 9 patients. An abnormal anterior femoral head and neck junction was present in 18 hips and fibrocystic change in 8. Acetabular retroversion was present in 11 hips. 63 sets of patient notes were reviewed, of which 49 were in-patients with abnormal MDCT arthrogram findings. Surgical correlation was available in 27 patients. There was a discrepancy between the findings of a labral tear in one patient (false negative, 90% sensitivity and 100% specificity) and the presence of acetabular cartilage loss (88% sensitivity and 100% specificity) and femoral cartilage loss (94% sensitivity and 100% specificity) in three patients. MDCT arthrography affords accurate detection of intra-articular hip pathology.

Post-operative imaging of soft tissue sarcomas.

Soft tissue sarcomas are uncommon malignancies that have a high risk of local recurrence despite adequate initial surgery. The aim of follow-up imaging with any malignancy is to detect recurrence promptly so that treatment can be instigated at the earliest possible opportunity. In this review article, we discuss the imaging modalities that can be employed to detect local recurrence following surgery for an extremity soft tissue sarcoma. The role of radiographs, computed tomography, magnetic resonance imaging and positron emission tomography is reviewed followed by a discussion on the imaging modalities useful in the detection of metastatic disease. Finally, we present a robust pathway that is suggested for the follow-up of patients with an extremity soft tissue sarcoma.

Tumour and tumour-like lesions of the intercondylar notch of the knee: a pictorial review.

A variety of tumours and tumour-like lesions are found in the intercondylar notch of the knee. MR imaging is the technique of choice in evaluating these conditions. Correlation with radiographs is important to identify those lesions containing calcification. This review article discusses the imaging features of tumour and tumour-like lesions involving the intercondylar notch with an emphasis on MR imaging features that suggest a specific diagnosis.

MRI of soft-tissue masses: the relationship between lesion size, depth, and diagnosis.

AIMS: To identify the relationship between depth and size of soft-tissue mass lesions relative to histological diagnosis in a range of malignant neoplastic, benign neoplastic, and non-neoplastic conditions on magnetic resonance imaging (MRI). METHOD: The MRI findings of 571 consecutive patients referred to a supra-regional orthopaedic oncology unit with a suspected soft-tissue neoplasm were reviewed and included in the study. The patient age, histological diagnosis, lesion size, anatomical location, and lesion depth (superficial or deep to fascia) were recorded. RESULTS: There were 288 males and 283 females (mean age 48 years, age range 2-92 years). The mean age was 54.1 years for malignant neoplastic lesions compared with 40.1 years for benign neoplastic and 45.4 years for non-neoplastic conditions. There was a significant age difference when malignant lesions were compared with benign neoplastic and non-neoplastic lesions (p<0.001). No significant relationship was present between lesion depth (480 deep, 91 superficial) and diagnosis (288 malignant neoplastic, 197 benign neoplastic and 86 non-neoplastic lesions). However, a significant relationship was identified between lesion size and diagnosis (p<0.001). Furthermore, a significant relationship was identified when lesion size greater than 5 cm, lesion depth, and diagnosis were analysed. CONCLUSION: Current guidelines suggest the most important variables for assessing risk of malignancy in a soft-tissue lesion include size, depth in relation to the fascia, increasing size, and pain. The current study suggests that relationship to fascia is less important as a predictor of malignant potential in a patient cohort treated at a supra-regional centre. Significant risk factors include increasing patient age and lesion size greater than or equal to 5 cm.

Imaging strategy for detecting lung metastases at presentation in patients with soft tissue sarcomas.

PURPOSE: To identify the risk of lung metastases at the time of diagnosis in patients with soft tissue sarcomas (STS) and to establish the optimum imaging strategy for the diagnosis of these metastases and whether this affects outcome. MATERIALS AND METHODS: A retrospective review of an orthopaedic oncology database identified 1170 patients with newly diagnosed STS during a 7.5-year period (1996-2004). The patient demographics, tumour type, size, depth, histology grade and presence of metastatic disease at presentation were studied. The chest radiograph (CXR)/computed tomography of the chest (CT chest) findings, performed as part of the initial staging study, were available in all patients. We estimated the efficacy of CXR in identifying pulmonary metastatic disease compared with CT chest and whether this affected patient survival. RESULTS: The incidence of metastases at diagnosis was 10% (116 patients), 8.3% (96 patients) had lung metastases on chest CT and 1.7% (20 patients) had metastases elsewhere. The risk of having lung metastases at diagnosis was 11.8% in high grade tumours, 7% in intermediate grade and 1.2% in low grade tumours. CXR alone detected 2/3 of all lung metastases. The positive predictive value of the CXR was 93.3%, the negative predictive value 96.7%, the sensitivity 60.8% and the specificity 99.6%. The accuracy was 96.9%. CT overestimated metastases in 4% with a sensitivity of 100%, specificity of 99.6% and accuracy of 99.6%. Median survival of patients with lung metastases at diagnosis was 11 months and there was no significant difference in survival between those who had metastases detected on CXR or purely on CT. DISCUSSION: We recommend that all patients with a suspected STS should have a CXR at presentation, prior to histological diagnosis. CT of the chest should then be performed in those patients with an abnormality on the presentation CXR and routinely in those patients who have large, deep seated or high/intermediate grade tumours and in certain histological subtypes where the incidence of lung metastases at diagnosis is known to be high. In our experience, this strategy will detect 93% of all chest metastases. With current treatment strategies for metastases, outcome is not likely to be affected by any delay in diagnosis.

Radiofrequency ablation of chondroblastoma: procedure technique, clinical and MR imaging follow up of four cases.

PURPOSE: The aim of this study is to describe the procedure technique, clinical and imaging outcomes of patients treated with radiofrequency ablation for chondroblastoma. MATERIALS AND METHODS: Four patients (female/male, 3:1; mean age, 13 years; age range; 9-16 years) underwent the procedure. All had pre-operative magnetic resonance imaging (MRI) and symptomatic, biopsy-proven chondroblastomas (two proximal femur, two proximal tibia). The lesion size ranged from 1.5 to 2.5 cm in maximal dimension (mean size, 1.8 cm). Bone access was gained with a Bonopty biopsy needle system (mean number of radiofrequency needle placements, 5; mean ablation time, 31 min). RESULTS: Clinical and MRI follow-up was available in all cases (mean, 12.25 months; range, 5-18 months). All patients reported resolution of symptoms at 2-6 weeks post ablation. At their most recent clinical follow-up, three patients remained completely asymptomatic with full return to normal activities and one patient had minor local discomfort (different pain pattern) that was not limiting activity. All four patients' follow-up MRI studies demonstrated resolution of the oedema pattern around the lesion and temporal evolution of the internal signal characteristics with fatty replacement. CONCLUSION: Radiofrequency ablation for chondroblastoma provides an alternative to surgical curettage, and we have demonstrated both a clinical improvement in symptoms and the follow-up MRI appearances.