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Objectives: The intervertebral disk has traditionally been imaged by magnetic resonance imaging (MRI); however, advances in sonography mean it can now be visualized with this modality. The objectives of this human cadaveric study were to visualize the internal structure of the lumbar intervertebral disks and map any defects. Shear wave sonography was explored as a method for assessing the disks. Materials and Methods: In a human cadaver, L4-L5 and L5-S1 disks were imaged with sonography through the anterior abdominal wall and directly through the anterior longitudinal ligament. Gray-scale images and shear wave elastography velocities were obtained. An MRI was performed for image comparison. Results: Defects in the disks were clearly seen with sonography, imaging through the anterior abdominal wall and also directly through the anterior longitudinal ligament. The defects identified on sonography were less well visualized on MRI. Shear wave velocities could only be obtained from the anterior aspect of the disk and were unreliable, primarily owing to the stiffness of the tissues. Conclusion: Sonography can provide an accurate map of defects within the disk, corresponding with MRI. Shear wave elastography should be used with caution in the human cadaveric intervertebral disk, acknowledging the many confounding factors influencing the measurements.

Fatty or part-fatty intraosseous lesions are occasionally encountered while imaging the skeletal system. A number of case reports have proposed involution of calcaneal bone cysts to intraosseous lipomas, but this has never been proven. This paper sets out to prove that simple bone cysts (SBCs) can involute to fatty lesions indistinguishable from intraosseous lipomas. The pathology and PACS databases at 2 specialist orthopedic hospitals were retrospectively interrogated for all cases of intraosseous lipomas or SBCs with cross-sectional imaging follow-up for SBCs and precursor or follow-up imaging for intraosseous lipomas, in the time period from August 2007 to December 2016. For intraosseous lipoma cases, these were only included if change in imaging appearances was observed. There was no case of change in the appearance in intraosseous lipomas. Six cases of SBC with cross-sectional imaging follow-up were identified in one participating hospital and none in the other. The 6 cases were comprised of 4 male and 2 female patients. Two were located in the proximal humerus, one in the proximal tibia, and 3 in the os calcis. All cases demonstrated filling in of the cystic lesion with fat from the periphery, in 2 cases complete filling in, and in 4 cases partial fatty conversion. SBCs can heal with fatty conversion of the cystic cavity, with partly cystic remnants. It is proposed that at least part of the so-called intraosseous lipomas are healed simple bone cysts.

Tumors around the elbow are infrequent, and delayed diagnosis is a common theme because of the low incidence and lack of familiarity. However, just like any other site, the radiologic work-up of musculoskeletal tumors around the elbow remains the same, with plain films the first investigation in a patient with a suspected bone tumor and ultrasound the first modality to evaluate a soft tissue lump. The management of both bone and soft tissue tumors around the elbow is unique because of a large number of important structures in an anatomically confined space and little normal tissue to spare without severely compromising the joint's function. Many benign nonneoplastic entities can mimic bone and soft tissue tumors on imaging. It is important to keep the characteristic imaging appearance in mind while formulating a differential diagnosis to avoid an unnecessary additional work-up. This article reviews the most common benign and malignant bone and soft tissue tumors around the elbow, mimickers, imaging features, and current therapeutic concepts.

Bone and soft tissue sarcomas are uncommon tumors that can occur within the upper extremity as well as elsewhere within the body. However, certain histopathological subtypes have increased affinity for the upper limb and even certain sites within the arm and hand. Other benign masses and tumor mimics, such as infection and traumatic lesions, are more common and imaging appearances can sometimes overlap with malignant lesions making diagnosis difficult. In this article, we explore the current options for imaging of these lesions as well as typical imaging appearances of the more common upper limb tumors.

Spine sports stress injuries account for a significant amount of time loss at play in athletes, particularly if left unrecognized and allowed to progress. Spondylolysis makes up most of these stress injuries. This article focuses on spondylolysis, bringing together discussion from the literature on its pathomechanics and the different imaging modalities used in its diagnosis. Radiologists should be aware of the limitations and more importantly the roles of different imaging modalities in guiding and dictating the management of spondylolysis. Other stress-related injuries in the spine are also discussed including but not limited to pedicle fracture and apophyseal ring injury.

The ring apophyses of the cervical spine have a variable appearance that changes with age. The times at which they appear and fuse at each level are not fixed. In this study, we aim to detail normal ranges of appearance of these ossification centers for each age group. One hundred and eighty patients under the age of 21 attending the Royal Stoke University Hospital for cervical spine radiographs were retrospectively identified. The presence or absence of ring apophyses at each cervical level and whether these had undergone fusion was reported, as were the thickness, length, and craniocaudal and anteroposterior distance of the apophysis from the vertebral body. The angulation of the apophysis relative to the endplate was also noted. The youngest patient in which apophyses were seen was aged 3, but apophyses were otherwise rarely seen before the age of 6. All apophyses were present from age 14, and the superior apophyses fused by the age of 18, although unfused inferior apophyses were still seen in the 20-year age group. It was observed that apophyses were rarely separated from the vertebral body by greater than 1 mm in craniocaudal distance (1%) or 2.5 mm in anteroposterior distance (2.6%) and the anterior apophysis was angulated towards the endplate in only 1% of cases. We have detailed the range of normal appearances of the ring apophyses of the developing cervical spine. Cervical spine apophyseal injury is thought to be rare, but knowledge of normative morphological features should help in this diagnosis.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare condition thought to be under-diagnosed, with a true prevalence of more than the 1 in 10,000 estimated. It is a condition that is classically described as polyostotic with a relapsing and remitting course, preferentially affecting the metaphyses of tubular bones in the pediatric population. Lesions have characteristic appearances of cortical hyperostosis and mixed lytic/sclerotic medullary appearances radiographically, with active osteitis and periostitis best seen with fluid-sensitive sequences on magnetic resonance imaging (MRI). There are reports of lesions resolving on follow-up radiographs and MRI scans, but no supporting images. In particular, although the marrow appearances and degree of osteitis have been shown to improve on MRI, complete resolution and remodeling back to normal has never been demonstrated. We present a case of a lesion that has completely healed and remodeled back to normal appearances on both radiographs and MRI, and consider this the standard for the often loosely used terms "normalization" and "resolution". We discuss the implications of this for our understanding of the natural history of CRMO, and how this adds weight to the condition being significantly under-diagnosed. It provides a "gold standard" to be aimed for when assessing treatments for CRMO, and the optimal outcomes that are possible. It also provides further insight into the potential of pediatric bone to recover and remodel when affected by inflammatory conditions.

This article provides an overview of the computed tomography (CT) and MR imaging appearances suggestive of spondyloarthritis, with a specific emphasis on the MR imaging findings of vertebral and sacroiliac involvement, and presents relevant clinical features that assist early diagnosis. CT is a sensitive imaging modality for the assessment of structural bone changes, but its clinical utility is limited. MR imaging is the modality of choice for early diagnosis, because of its ability to depict inflammation long before structural bone damage occurs, for monitoring of disease activity, and for evaluating therapeutic response.

Background Paediatric spinal injury is rare and exhibits many unique features. Attending clinicians and radiologists often lack knowledge, expertise and experience in dealing with a potential injury to the paediatric spine. Within the paediatric age range itself there are different age-dependent mechanisms that can injure the paediatric spine. Moreover, the anatomical features and degree of osseous maturity of the developing paediatric spine determine the biomechanical characteristics which promote unique patterns of spinal injury in each paediatric age group. Methods An expert illustrated narrative review of the literature. Results Multiple factors make the imaging interpretation of the injured paediatric spine challenging. Each imaging modality has strengths and weaknesses in depicting spinal anatomy which vary with the type of spinal injury and age of the paediatric patient. Conclusions Attending doctors need to be familiar with the imaging appearances of the normal paediatric spine, its normal variants as well as the imaging features characteristics of paediatric spinal injury seen on radiographs, computed tomography and magnetic resonance imaging.

Pelvic ring fractures are a common consequence of high-energy blunt trauma with a high rate of morbidity and mortality due to associated injuries, especially to the head, pelvic viscera, and vascular structures. The Young and Burgess classification system is the most widely utilized for categorizing pelvic ring injuries and assessing stability. The initial identification of these injuries often comes from an anteroposterior radiograph; however, computed tomography examination with three-dimensional volume-rendered reconstructions represents the reference standard and has essentially eliminated the requirement for inlet and outlet views. The appropriate treatment depends on a good knowledge of the anatomy and biomechanics of the pelvis. This review article underlines the importance of the integrity of ligaments to pelvic stability and describes the patterns of pelvic ring injuries and their associated mechanisms of injury.

Objectives Peripheral bone infection (PBI) and prosthetic joint infection (PJI) are two different infectious conditions of the musculoskeletal system. They have in common to be quite challenging to be diagnosed and no clear diagnostic flowchart has been established. Thus, a conjoined initiative on these two topics has been initiated by the European Society of Radiology (ESR), the European Association of Nuclear Medicine (EANM), the European Bone and Joint Infection Society (EBJIS), and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID). The purpose of this work is to provide an overview on the two consensus documents on PBI and PJI that originated by the conjoined work of the ESR, EANM, and EBJIS (with ESCMID endorsement).Methods and results After literature search, a list of 18 statements for PBI and 25 statements for PJI were drafted in consensus on the most debated diagnostic challenges on these two topics, with emphasis on imaging.Conclusions Overall, white blood cell scintigraphy and magnetic resonance imaging have individually demonstrated the highest diagnostic performance over other imaging modalities for the diagnosis of PBI and PJI. However, the choice of which advanced diagnostic modality to use first depends on several factors, such as the benefit for the patient, local experience of imaging specialists, costs, and availability. Since robust, comparative studies among most tests do not exist, the proposed flowcharts are based not only on existing literature but also on the opinion of multiple experts involved on these topics.Key PointsFor peripheral bone infection and prosthetic joint infection, white blood cell and magnetic resonance imaging have individually demonstrated the highest diagnostic performance over other imaging modalities.Two evidence- and expert-based diagnostic flowcharts involving variable combination of laboratory tests, biopsy methods, and radiological and nuclear medicine imaging modalities are proposed by a multi-society expert panel.Clinical application of these flowcharts depends on several factors, such as the benefit for the patient, local experience, costs, and availability.

Various radiological measurements have been described in the long bones of the upper and lower limbs. These help in the diagnosis of diseased states but are also important as a useful tool in planning surgical treatment and subsequent follow-up of such conditions. In certain conditions, radiological measurements are used to assess disease progression (e.g. infantile tibia vara vs. physiological bowing). These measurements may be related to an individual long bone or the alignment of the bones and joints in the entire limb. Within individual bones, there may be an abnormality in the length of the bone (e.g. ulnar variance), angular deformity in a sagittal or coronal plane at various levels (e.g. post-traumatic deformity) or an abnormality in the anatomical twist around the longitudinal axis (e.g. femoral and tibial torsion). Deformity in individual bones or the joint surfaces associated with soft tissue laxity may result in abnormal alignment of the entire limb. This results in abnormal biomechanics and disproportionate transmission of load within the weight bearing joints. It is widely accepted that a malaligned state may lead to degenerative changes in the adjacent joints. Indeed the most important long-term consequence of a deformity in a long bone or malalignment in the entire limb is the early development of degenerative arthritis. Within the paediatric population, there is an increased potential of remodelling with growth, and this factor should be kept in mind whilst planning treatment. There may be spontaneous correction of angulation with growth and a larger angular deformity may be tolerated as compared to adults. In terms of length discrepancies, one should also keep in mind the predicted length at skeletal maturity. It is therefore important to be aware of the technique of performing these measurements and to have knowledge of the normal reference values.

Accurate and reproducible measurements related to the paediatric hip and pelvis can be challenging. A standardised radiograph requires close attention to positioning of the infant or child to ensure that it is neither rotated nor inclined. Even a minor degree of obliquity can result in great variability of measurement. In the young child several bony landmarks are not yet established and difficulty can be encountered in determining the appropriate point of measurement. Awareness of these issues allows one to employ the best and most readily reproducible measurement at a particular age or stage of development. Although ultrasound plays an important role in evaluation of paediatric hip dysplasia, this is mainly in infants and radiography continues to play an important role in the older child and adult. There are a wide range of measurements available for different clinical scenarios. These will be addressed in this chapter.

OBJECTIVE: To predict accurately whether a soft tissue mass was benign or malignant and to characterize its type using ultrasound, shear wave elastography and MRI. We hypothesized that with the addition of shear wave elastography, it would be possible to determine a threshold velocity value to classify a lesion as benign or malignant. MATERIALS AND METHODS: A total of 151 consecutive, consenting adult patients were prospectively recruited to this study in a tertiary referral musculoskeletal oncology centre. All lesions were assessed with ultrasound, including B mode, Doppler and shear wave elastography measurements. One hundred thirty-eight patients also underwent MRI of the lesion. A histological diagnosis was obtained for all lesions. RESULTS: Malignant lesions were larger than benign lesions and had a greater Doppler activity. There was no useful threshold shear wave velocity to differentiate between benign and malignant lesions. Longitudinal and transverse shear wave velocities were strongly positively correlated with each other. An inverse correlation was shown with lesion size and depth, regardless of whether it was benign or malignant. A logistic regression model combining the ultrasound and MRI characteristics did not confidently classify a lesion as benign or malignant and was inferior to expert opinion. CONCLUSION: The strongest predictors of malignancy are large lesion size and high vascularity. The combination of all ultrasound characteristics (including shear wave elastography) and MRI features does not confidently classify a lesion as benign or malignant, and histological diagnosis remains the gold standard.

The human spine is a highly specialized structure that protects the neuraxis and supports the body during movement, but its complex structure is a challenge for imaging. Radiographs can provide fine bony detail, but lack soft tissue definition and can be complicated by overlying structures. MR imaging allow(s) excellent soft tissue contrast, but some bony abnormalities can be difficult to discern. This makes the 2 modalities highly complementary. In this article, the authors discuss the correlation between radiographic and MR imaging appearances focusing first on disease affecting the vertebral body itself, its surrounding structures, and finally global spinal alignment.

Paget disease (PD) is a common disease of bone associated with abnormal bone turnover that in turn is due to an imbalance between osteoclastic and osteoblastic activity. There is good evidence that PD is reducing in incidence, prevalence, and severity. The disease is most often asymptomatic and is usually detected incidentally on imaging examinations performed for other reasons. The features of PD are relatively specific on radiographs and computed tomography. However, the appearances on magnetic resonance imaging are subtle and nonspecific, although it has become the initial imaging choice for several clinical indications including back pain, neurologic dysfunction, and knee pain. It is therefore important to be familiar with the various imaging appearances of this relatively common disease in an increasingly aging population. In this article we discuss the various imaging appearances of PD and its complications.

Introduction In adults with a suspicion of peripheral bone infection, evidence-based guidelines in choosing the most accurate diagnostic strategy are lacking. Aim and methods To provide an evidence-based, multidisciplinary consensus document on the diagnostic management of adult patients with PBIs, we performed a systematic review of relevant infectious, microbiological, orthopedic, radiological, and nuclear medicine literature. Delegates from four European societies (European Bone and Joint Infection Society, European Society of Microbiology and Infectious Diseases, European Society or Radiology, and European Association of Nuclear Medicine) defined clinical questions to be addressed, thoroughly reviewed the literature pertinent to each of the questions, and thereby evaluated the diagnostic accuracy of each diagnostic technique. Inclusion of the papers per statement was based on a PICO (Population/problem – Intervention/indicator – Comparator – Outcome) question following the strategy reported by the Oxford Centre for Evidence-based Medicine. For each statement, the level of evidence was graded according to the 2011 review of the Oxford Centre for Evidence-based Medicine. All approved statements were addressed taking into consideration the available diagnostic procedures, patient acceptance, tolerability, complications, and costs in Europe. Finally, a commonly agreed-upon diagnostic flowchart was developed. Electronic supplementary material The online version of this article (10.1007/s00259-019-4262-x) contains supplementary material, which is available to authorized users.

Background For the diagnosis of prosthetic joint infection, real evidence-based guidelines to aid clinicians in choosing the most accurate diagnostic strategy are lacking. Aim and Methods To address this need, we performed a multidisciplinary systematic review of relevant nuclear medicine, radiological, orthopaedic, infectious, and microbiological literature to define the diagnostic accuracy of each diagnostic technique and to address and provide evidence-based answers on uniform statements for each topic that was found to be important to develop a commonly agreed upon diagnostic flowchart. Results and Conclusion The approach used to prepare this set of multidisciplinary guidelines was to define statements of interest and follow the procedure indicated by the Oxford Centre for Evidence-based Medicine (OCEBM). Electronic supplementary material The online version of this article (10.1007/s00259-019-4263-9) contains supplementary material, which is available to authorized users.

The study reports the prospective outcome of treating severe recalcitrant fracture nonunion in patients with autologous bone marrow‐derived mesenchymal stromal cells (BMSC) from 2003 to 2010 and analyze predictors of union. Autologous BMSC were culture expanded and inserted at nonunion site with or without carriers in addition to surgical stabilization of the fracture. Radiological union was ascertained by musculoskeletal radiologists on plain radiographs and/or CT scans. A logistic regression analysis was performed with cell‐expansion parameters (cell numbers, cell doubling time) and known clinical factors (e.g., smoking and diabetes) as independent variables and fracture union as the dependent variable to identify the factors that influence bony healing. An Eq5D index score assessed the effect of treatment on general quality of health. A total of 35 patients (mean age 51+/−13 years) with established nonunion (median 2.9 years, 1–33) and, at least one failed nonunion surgery (median 4,1–14) received treatment. Fracture union was achieved in 21 patients (60%; 95%CI 44–75) at 2.6 years. Multiple penalized logistic regression revealed faster cell doubling time (p = 0.07), absence of diabetes (p = 0.003), less previous surgeries (p = 0.008), and lower age at cell implantation (p = 0.02) were significant predictors for fracture union. A significant increase in Eq5D index (p = 0.01) was noted with a mean rise of the score by 0.34 units (95%CI 0.11–0.58) at 1 year following the study. In summary, the study revealed cell doubling time as a novel in vitro parameter in conjunction with age, multiple surgeries, and diabetes as being significant predictors of the fracture union. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. J Orthop Res 37:1303–1309, 2019.

Pigmented villonodular synovitis (PVNS) is normally treated by arthroscopic or open surgical excision. We present our initial experience with radiofrequency thermo-ablation (RF ablation) of PVNS located in an inaccessible location in the knee. Review of all patients with histologically proven PVNS treated with RF ablation and with at least 2-year follow-up. Three patients met inclusion criteria and were treated with RF ablation. Two of the patients were treated successfully by one ablation procedure. One of the three patients had a recurrence which was also treated successfully by repeat RF ablation. There were no complications and all patients returned to their previous occupations following RF ablation. In this study we demonstrated the feasibility of performing RF ablation to treat PVNS in relatively inaccessible locations with curative intent. We have also discussed various post-ablation imaging appearances which can confound the assessment for residual/recurrent disease.

Orthopaedic surgical studies have shown that variations in the vertical distance between the tip of the coracoid process and the supra-glenoid tubercle alter the shape of the subcoracoid outlet. Our objective was to measure the vertical distance between the coracoid tip and the supra-glenoid tubercle (CTGT) on MR and to assess whether this showed better correlation with rotator cuff pathology compared with the axial coraco-humeral distance. A retrospective review was performed of 100 consecutive shoulder MR arthrograms. Vertical distance between the coracoid tip and the supraglenoid tubercle was measured in the sagittal oblique plane. Separate assessment was then made of tendon pathology of the subscapularis, supraspinatus and long head of biceps tendons. Axial coraco-humeral distance was then measured. Correlation between tendon abnormalities and the two measurements was then made. Of the 100 cases, 42 had subscapularis tendon lesions, 21 had lesions of the long head of biceps and 53 had supraspinatus tendon lesions. Mean vertical distance from the coracoid tip to supraglenoid tubercle was greater in those with lesions of any of these tendons and was statistically significant for the supraspinatus group (P = 0.005). Reduced axial coraco-humeral distance was also seen in patients with tendinopathy, although with less statistically significant difference (p = 0.059). Our results support orthopaedic studies that have shown that the vertical distance between the coracoid tip and the supraglenoid tubercle increases the incidence and risk of rotator cuff disease by altering the shape of the subcoracoid outlet.

Spondyloarthropathy has been described radiographically in patients following paralysis from spinal cord trauma. Onset of these findings after cauda equina syndrome have not been reported previously. Furthermore, the magnetic resonance documentation of its early evolution has not been recorded. We report a case of early-onset spondyloarthropathy shown by magnetic resonance imaging (MRI) in a patient with cauda equina syndrome due to bilateral sacral insufficiency fractures. Unique case study review, one case. Review of the clinical case notes and imaging including initial and subsequent MR imaging. The initial MRI of the lumbosacral spine showed bilateral sacral insufficiency fractures with a kyphotic deformity. The vertebral bodies were normal on the initial computed tomography and MRI studies, which did not reveal pre-existing features of sacroiliitis. The second MRI performed 5 months later clearly showed spondylitis at multiple vertebral levels with partial resolution 18 months post injury. Spondyloarthropathy in patients with paralysis due to spinal cord injury is well documented in the English language literature, but until now this has not been demonstrated by MRI. It is a rare complication of traumatic cauda equina syndrome that commences soon after the traumatic event and can resolve spontaneously.

SAPHO and recurrent multifocal osteomyelitis are complex inflammatory conditions that clinical radiologists play an essential part in diagnosing. They present with a wide range of musculoskeletal and skin manifestations, and exhibit several key diagnostic features that, when present, make the diagnoses unequivocal. The overall population group is young. Diagnostic delay is common with a relapsing and remitting clinical course and often subtle early radiologic findings. This article provides an up-to-date insight into both conditions, including their multifaceted pathogenesis, effective therapeutic options, and advanced imaging features, to arm radiologists with the knowledge required to make the diagnoses confidently in a timely manner.

Spine trauma is a devastating event with high morbidity and mortality and many additional medical, psychological, social, and financial consequences for patients, their families, and society. The thoracolumbar spine represents the most common area fractured in the spine. Morphology, extent, and the location of fracture lines are important determinants of stability, which is the core issue in the assessment of vertebral injuries, dictating conservative or surgical treatment. After hospital admission and clinical stabilization, patients with potential spine trauma are screened radiologically. Imaging analysis is based on radiographs, computed tomography, and magnetic resonance imaging. Understanding these three tools is essential to get a clear picture of the extent of any vertebral fracture. A multidisciplinary team should provide assessment, treatment, and education to patients with a spinal injury to achieve a treatment tailored for each patient. Thoracolumbar trauma focusing on spinal biomechanics, stability, imaging modalities, morphology patterns, classifications, and treatment are discussed and reviewed.

Stress fractures, that is fatigue and insufficiency fractures, of the pelvis and lower limb come in many guises. Most doctors are familiar with typical sacral, tibial or metatarsal stress fractures. However, even common and typical presentations can pose diagnostic difficulties especially early after the onset of clinical symptoms. This article reviews the aetiology and pathophysiology of stress fractures and their reflection in the imaging appearances. The role of varying imaging modalities is laid out and typical findings are demonstrated. Emphasis is given to sometimes less well-appreciated fractures, which might be missed and can have devastating consequences for longer term patient outcomes. In particular, atypical femoral shaft fractures and their relationship to bisphosphonates are discussed. Migrating bone marrow oedema syndrome, transient osteoporosis and spontaneous osteonecrosis are reviewed as manifestations of stress fractures. Radiotherapy-related stress fractures are examined in more detail. An overview of typical sites of stress fractures in the pelvis and lower limbs and their particular clinical relevance concludes this review. Teaching Points • Stress fractures indicate bone fatigue or insufficiency or a combination of these. • Radiographic visibility of stress fractures is delayed by 2 to 3 weeks. • MRI is the most sensitive and specific modality for stress fractures. • Stress fractures are often multiple; the underlying cause should be evaluated. • Infratrochanteric lateral femoral fractures suggest an atypical femoral fracture (AFF); endocrinologist referral is advisable.

To assess the safety and effectiveness of image-guided radiofrequency ablation (RF ablation) in the treatment of chondroblastomas as an alternative to surgery.Twelve patients with histologically proven chondroblastoma at our institution from 2003 to date. We reviewed the indications, recurrences and complications in patients who underwent RF ablation.Twelve patients were diagnosed with chondroblastoma. Out of these, 8 patients (6 male, 2 female, mean age 17 years) with chondroblastoma (mean size 2.7 cm) underwent RF ablation. Multitine expandable electrodes were used in all patients. The number of probe positions needed varied from 1 to 4 and lesions were ablated at 90 °C for 5 min at each probe position. The tumours were successfully treated and all patients became asymptomatic. There were no recurrences. There were 2 patients with knee complications, 1 with minor asymptomatic infraction of the subchondral bone and a second patient with osteonecrosis/chondrolysis.Radiofrequency ablation appears to be a safe and effective alternative to surgical treatment with a low risk of recurrence and complications for most chondroblastomas. RF ablation is probably superior to surgery when chondroblastomas are small (less than 2.5 cm) with an intact bony margin with subchondral bone and in areas of difficult surgical access.

Although pathology at the first mobile segment above a lumbosacral transitional vertebra (LSTV) is a known source of spinal symptoms, nerve root compression below an LSTV, has only sporadically been reported. Our objective was to assess the prevalence of nerve root entrapment below an LSTV, review the causes of entrapment, and correlate with presenting symptoms. A retrospective review of MR and CT examinations of the lumbar spine was performed over a 5.5-year period in which the words “transitional vertebra” were mentioned in the report. Nerve root compression below an LSTV was assessed as well as the subtype of transitional vertebra. Correlation with clinical symptoms at referral was made. MR and CT examinations were also reviewed to exclude any other cause of symptoms above the LSTV. One hundred seventy-four patients were included in the study. Neural compression by new bone formation below an LSTV was demonstrated in 23 patients (13 %). In all of these patients, there was a pseudarthrosis present on the side of compression due to partial sacralization with incomplete fusion. In three of these patients (13 %), there was symptomatic correlation with no other cause of radiculopathy demonstrated. A further 13 patients (57 %) had correlating symptoms that may in part be attributable to compression below an LSTV. Nerve root compression below an LSTV occurs with a prevalence of 13 % and can be symptomatic in up to 70 % of these patients. This region should therefore be carefully assessed in all symptomatic patients with an LSTV.

Conventional radiographs and CT are primary investigations in spinal trauma. However MRI is the primary technique in the assessment of degenerative and inflammatory disorders. There are occasions when conventional radiographs, CT and bone scintigraphy assist in the diagnosis of degenerative and inflammatory disorders.

Paget's disease of bone is a disorder of bone remodelling, leading to changes in the architecture and overall appearance of the bone. The disorder may be monostotic or polyostotic and affect any bone in the body, although most commonly it involves the spine, pelvis, skull and femur. This article explores the different imaging modalities used in the assessment of Paget's disease of bone in its different phases. The relative merits of each imaging modality is discussed with illustrative examples, in particular with respect to radiographs, nuclear medicine bone scan, computed tomography (CT) and magnetic resonance imaging (MRI).

Trichorhinophalangeal syndrome type II is a rare genetic disorder with the few published case reports mainly reporting the radiographic skeletal manifestations. There are no published imaging reports of long bone cysts involving multiple bones in this condition. We report a unique case of bone cysts involving multiple long bones detected with MRI in a patient with trichorhinophalangeal syndrome type II complicated by a subsequent pathological fracture. It is possible that the bone cysts are a previously undescribed feature of this syndrome; however, the evidence is insufficient to establish a definite association. Chromosomal abnormality identified in this patient is consistent with trichorhinophalangeal syndrome type II with no unusual features. Although the nature of these bone cysts is unclear, they are one of the causes of the known increased fracture risk observed in this syndrome.

The bulk of spinal imaging is still performed with conventional two-dimensional sequences. This study assesses the suitability of three-dimensional sampling perfection with application-optimised contrasts using a different flip angle evolutions (SPACE) sequence for routine spinal imaging.62 MRI examinations of the spine were evaluated by 2 examiners in consensus for the depiction of anatomy and presence of artefact. We noted pathologies that might be missed using the SPACE sequence only or the SPACE and a sagittal T(1) weighted sequence. The reference standards were sagittal and axial T(1) weighted and T(2) weighted sequences. At a later date the evaluation was repeated by one of the original examiners and an additional examiner.There was good agreement of the single evaluations and consensus evaluation for the conventional sequences: κ0.8, confidence interval (CI)0.6-1.0. For the SPACE sequence, depiction of anatomy was very good for 84% of cases, with high interobserver agreement, but there was poor interobserver agreement for other cases. For artefact assessment of SPACE, κ=0.92, CI=0.92-1.0. The SPACE sequence was superior to conventional sequences for depiction of anatomy and artefact resistance. The SPACE sequence occasionally missed bone marrow oedema. In conjunction with sagittal T(1) weighted sequences, no abnormality was missed. The isotropic SPACE sequence was superior to conventional sequences in imaging difficult anatomy such as in scoliosis and spondylolysis.The SPACE sequence allows excellent assessment of anatomy owing to high spatial resolution and resistance to artefact. The sensitivity for bone marrow abnormalities is limited.

The uncommon variant of degenerative hip joint disease, termed rapidly progressive osteoarthritis, and highlighted by severe joint space loss and osteochondral disintegration, is well established. We present a similar unusual subset in the lumbar spine termed destructive discovertebral degenerative disease (DDDD) with radiological features of vertebral malalignment, severe disc resorption, and "bone sand" formation secondary to vertebral fragmentation. Co-existing metabolic bone disease is likely to promote the development of DDDD of the lumbar spine, which presents with back pain and sciatica due to nerve root compression by the "bone sand" in the epidural space. MRI and CT play a complimentary role in making the diagnosis.

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) is an umbrella acronym for inflammatory clinical conditions whose common denominator is aseptic osteoarticular involvement with characteristic skin lesions. It involves all ages, can involve any skeletal site, and has variable imaging appearances depending on the stage/age of the lesion and imaging method. It mimics important differentials including infection and neoplasia. Awareness of the imaging features, especially in the spine, facilitates early diagnosis, prevents repeated biopsies, and avoids unnecessary surgery, while initiating appropriate treatment.

We noted a large amount of intravenous gas during balloon kyphoplasty on CT imaging. Formal assessment to understand the extent, possible causes and implications was undertaken. Ten consecutive cases of balloon kyphoplasty were performed under general anaesthesia in the prone position, on a single vertebral level using a two-step technique under combined fluoroscopic and CT guidance. CT of the affected vertebra was performed before, after, and intermittently during the procedure. In 2 cases delayed CT was carried out in the supine position. Gas was seen on CT imaging, but not on conventional fluoroscopy. The gas is most likely to be air introduced during the procedure and was seen in the epidural and paravertebral venous plexus, posterior intercostal veins, renal veins, IVC and azygos vein. The average measured volume of gas seen on the post-procedure CT imaging was 1.07 mL, range 0.16–3.97 mL. There was no correlation of the measured amount of gas to the procedure duration or location, the use of a curette or the injected cement volume. Delayed CT in the supine position no longer showed air in the local venous system. Balloon kyphoplasty is associated with the fluoroscopically invisible introduction of air into the vertebral and paravertebral veins and deep systemic veins and is likely to be much more extensive than identified on CT imaging. There is potential for serious air embolism in kyphoplasty and if there is a sudden deterioration in patient condition during the procedure the possibility of this complication needs to be considered.

The knee is a common area of the body to undergo interventional procedures. This article discusses image-guided interventional issues specific to the knee area. The soft tissues in and around the knee are frequently affected by sport-related injuries and often need image-guided intervention. This article details the specific technical issues related to intervention in these soft tissues, including the iliotibial tract, fat pads, patellar tendon and other tendons, bursae and the meniscus. Most often, simple procedures such as injection and aspiration are performed without image guidance. Rarely image-guided diagnostic arthrography and therapeutic joint injections are necessary. The technique, indications and diagnostic considerations for arthrography are discussed in this article. Primary bone and soft-tissue tumours may involve the knee and adjacent soft tissues. Image-guided biopsies are frequently necessary for these lesions; this article details the technical issues related to image-guided biopsy around the knee. A number of newer ablation treatments are now available, including cryoablation, high-frequency ultrasound and microwave ablation. Radiofrequency ablation, however, still remains the most commonly employed ablation technique. The indications, technical and therapeutic considerations related to the application of this technique around the knee are discussed here. Finally, we briefly discuss some newer, but as of yet, unproven image-guided interventions for osteochondral lesions and Brodie's abscess.

Soft tissue and bone infection involving the foot is one of the most common long-term complications of diabetes mellitus, implying a serious impairment in quality of life for patients in the advanced stages of the disease. Neuropathic osteoarthropathy often coexists and differentiating between these two entities is commonly challenging, but crucial, as the management may differ substantially. The importance of correct diagnosis cannot be understated and effective management requires a multidisciplinary approach owing to the complicated nature of therapy in such patients. A missed diagnosis has a high likelihood of major morbidity for the patient, including limb amputation, and over-diagnosis results in a great socioeconomic challenge for healthcare systems, the over-utilization of healthcare resources, and the unwise use of antibiotics. Diagnosis is largely based on clinical signs supplemented by various imaging modalities such as radiography, MR imaging, and hybrid imaging techniques such as F-18 fluorodeoxyglucose-positron emission tomography. In the interests of the management of diabetic foot complications, this review article is aimed on the one hand at providing radiologists with important clinical knowledge, and on the other hand to equip clinicians with relevant radiological semiotics.

Successful healing of a nine-year tibial nonunion resistant to six previous surgical procedures was achieved by tissue engineering. We used autologous bone marrow stromal cells (BMSCs) expanded to 5 × 106 cells after three weeks’ tissue culture. Calcium sulphate (CaSO4) in pellet form was combined with these cells at operation. The nonunion was clinically and radiologically healed two months after implantation. This is the description of on healing of a long-standing tibial nonunion by tissue engineering. The successful combination of BMSCs and CaSO4 has not to our knowledge been reported in a clinical setting.

This article reviews the pathophysiology of spinal infection and its relevance for imaging. Magnetic resonance imaging (MRI) is the modality with by far the best sensitivity and specificity for spinal infection. The imaging appearances of spinal infection in MRI are outlined, and imaging techniques are discussed. The problems of clinical diagnosis are outlined. There is some emphasis on the MRI differentiation of pyogenic and nonpyogenic infection and on the differential diagnosis of spinal infection centered on the imaging presentation.

Clearance of the traumatic cervical spine is a subject affecting most healthcare professionals dealing with trauma patients. There is a host of often contradictory literature making it hard for an interested reader to come to their own informed opinion based on the current evidence. This review aims to outline the relevant literature for the clearance of the traumatic cervical spine with the particular aim of highlighting the contradictions, controversies and unanswered questions still besetting this important subject. A brief, subjective opinion for a combined clinical and imaging protocol for clearance of the traumatic cervical spine is given.

Sacral insufficiency fractures are a well recognised cause for low back, buttock and groin pain in the elderly. However, over a 4 year period, four patients have presented with symptoms of cauda equina syndrome, who were found on investigation to have acute sacral insufficiency fracture without any other aetiological spinal abnormality.Four patients who presented to the spinal surgeons of our institution with symptoms of cauda equina syndrome were referred for spinal MR. Sagittal and axial T1 and T2 weighted turbo spin echo sequences of the lower thoracic and lumbar spine were performed on all patients. Subsequent studies included MR of the sacrum supplemented where appropriate by CT and technetium MDP bone scintigraphy.No evidence of a compressive lesion of the lower thoracic or lumbar spine was present in any of the four patients. Dedicated MR examination of the sacrum in these patients revealed unilateral acute insufficiency fractures involving zone 1 from S1 to S3 extending from the sacro-iliac joint to the lateral margin of the sacral foramen. There was no evidence of compression of the sacral nerve roots. The possible mechanism for the symptomatic presentation is discussed.Sacral insufficiency fractures should be excluded in elderly or osteoporotic patients presenting with cauda equina syndrome who have no evidence of compression in the thoraco-lumbar MR studies.

Laboratory investigations play an important role in the diagnosis of rheumatic disorders but many tests are of limited specificity. It is therefore important to select tests in the light of careful clinical assessment rather than blindly sending off a battery of requests, as the results may be confusing. We review the frequency of autoantibodies in different disorders and their value for diagnosis and, in some cases, for prognosis and monitoring. We also review the relative merits and disadvantages of plain radiographs, ultrasound, isotope, CT and MR imaging for different types of musculoskeletal problem. Finally we describe the typical imaging characteristics of degenerative and inflammatory disorders including rheumatoid arthritis and seronegative spondyloarthropathies in the peripheral joints and spine.

Study design This is a case series in which case notes review and telephone interview update were used to assess the outcome following coccygectomy. Objective To correlate the clinical results of coccygectomy with histology and discography of the sacrococcygeal and intercoccygeal segments. Summary of background data Clinicians regard chronic disabling pain in the sacrococcygeal region with much dismay because of the reputed unpredictability of the treatment outcome. Methods A total of 38 patients had coccygectomy for intractable coccydynia, and 31 were available for follow-up. The excised specimen with intact sacrococcygeal joint was sent for histologic examination in 22 patients. There were 6 patients investigated using sacrococcygeal and intercoccygeal discography. Results Mean postoperative follow-up was 6.75 years (range 2-16). There were 16 patients who benefited highly from the surgery, and 6 benefited to some extent, giving an overall beneficial result of 71%. Of all specimens, 86.3% had histologic changes of degeneration. Moderate-to-severe degenerate changes in sacrococcygeal and intercoccygeal joints on histology were found in 54.5% of patients. Of these patients, 83.3% did well with surgery. Only 57.1% of those patients with mild changes did well. There were 2 patients who had positive discography, and both did well with surgery. Three patients had negative diskographies, and 2 of them had a poor result, and 1 had only some relief. Conclusions It is possible that degenerate changes in sacrococcygeal discs and/or intercoccygeal discs are associated with pain. Surgical results are better in those with a severe degree of degenerative change. Coccygectomy remains a successful treatment for a majority of severely disabled patients with coccydynia.

The standard treatment for chondroblastoma is surgery, which can be difficult and disabling due to its apo- or epiphyseal location. Radiofrequency (RF) ablation potentially offers a minimally invasive alternative. The often large size of chondroblastomas can make treatment with plain electrode systems difficult or impossible. This article describes the preliminary experience of RF treatment of chondroblastomas with a multi-tined expandable RF electrode system. Four cases of CT guided RF treatment are described. The tumour was successfully treated in all cases. In two cases, complications occurred; infraction of a subarticular chondroblastoma in one case and cartilage and bone damage in the unaffected compartment of a knee joint in the other. Radiofrequency treatment near a joint surface threatens the integrity of cartilage and therefore long-term joint function. In weight-bearing areas, the lack of bone replacement in successfully treated lesions contributes to the risk of mechanical failure. Multi-tined expandable electrode systems allow the treatment of large chondroblastomas. In weight-bearing joints and lesions near to the articular cartilage, there is a risk of cartilage damage and mechanical weakening of the bone. In lesions without these caveats, RF ablation appears promising. The potential risks and benefits need to be evaluated for each case individually.