Normal Bone Marrow and Non-neoplastic Systemic Hematopoietic Disorders in the Adult.

This article provides an overview of the imaging appearances of normal adult bone marrow with an emphasis on magnetic resonance imaging. We also review the cellular processes and imaging features of normal developmental yellow-to-red marrow conversion and compensatory physiologic or pathologic red marrow reconversion. Key imaging features that differentiate between normal adult marrow, normal variants, non-neoplastic hematopoietic disorders, and malignant marrow disease are discussed, as well as posttreatment changes.

Percutaneous pars interarticularis screw fixation: a technical note.

PURPOSE: A conventional midline posterior approach is used for most of the described surgical techniques. We describe a technique of percutaneous fixation of the pars interarticularis, augmented where necessary by grafting the defect, which minimises muscle injury. METHOD: A 4.5 mm partially threaded dynamic compression screw is placed over a wire inserted percutaneously across the pars interarticularis defect. Compression is achieved across the pars interarticularis defect on placement of the screw. The screw is locked in a compressed state. RESULTS: The patient is mobilised the same day with a corset for comfort and discharged the following day. Aerobic fitness is maintained for 3 months; then, focused rehabilitation performed until a CT scan confirms healing at 5-6 months, at which stage full (sports) activity is resumed. CONCLUSIONS: The minimal tissue injury and small incision used allow for the minimising of complications and for a rapid recovery and discharge from hospital. With adolescents, we have the opportunity to treat symptomatic pars interarticularis defects with minimal disruption to their academic and physical development.

The use of ultrasound in comparison to radiography in magnetically controlled growth rod lengthening measurement: a prospective study.

PURPOSE: This study investigated whether ultrasound (U/S) is an alternative to radiography when measuring magnetically controlled growth rod (MCGR) length in order to reduce radiation exposure. Distractible spinal growth rods are the gold standard when treating early-onset scoliosis (EOS). METHODS: This was a prospective series. Patients were already undergoing EOS treatment using MCGRs. Forty-eight data points measured using radiography and U/S were compared. Each U/S data point was measured three times by three observers to assess intra- and inter-observer reliability. The radiation dose of the pre-lengthening and post-lengthening radiographs was recorded. RESULTS: The average rod lengths were 1.322 cm with U/S and 1.329 cm with radiography. The ICC (radiography vs. U/S) was 0.992 (95 % confidence interval (CI) 0.976, 1.000). The inter- and intra-rater reliability of U/S had an ICC of 0.987 (95 % CI 0.966, 1.000) and 0.983 (95 % CI 0.956, 1.000), respectively. The mean total effective radiation dose of the pre-lengthening and post-lengthening PA spinal radiographs was 0.26 mSv with a mean attributable lifetime cancer risk of one in 39,686 per lengthening. CONCLUSION: U/S highly agrees with radiography when measuring MCGR length. It has a high inter- and intra-observer reliability and does not require radiation exposure. Although U/S allows accurate MCGR measurement and soft tissue assessment, patients will still need occasional radiographs to assess spine bony elements, overall spinal balance and scoliosis correction. Combining radiography and U/S allows patient monitoring and accurate MCGR measurement whilst decreasing patients' radiation exposure.

Functional outcome following primary total knee arthroplasty cannot be predicted using the initial post-operative radiograph.

Obtaining standardised post-operative radiographs following total knee arthroplasty is common practice. Little is known regarding how measurements taken from the initial post-operative radiograph correlate to functional outcome. The initial post-operative radiographs for 110 primary total knee arthroplasties were reviewed retrospectively. Femoral and tibial component alignment was measured by two independent consultant radiologists. Functional outcome was assessed by the Oxford Knee Score pre-operatively and one year post-operatively. Correlation was determined by Pearson correlation analysis. There was no significant correlation between the radiographic measurements with the one year post-operative Oxford Knee Score nor was there significant correlation with the difference in pre-operative and post-operative scores. The initial post-operative radiograph cannot be used as a tool to reliably predict functional outcome at one year.

Changes in physiological, functional and structural markers of cystic fibrosis lung disease with treatment of a pulmonary exacerbation.

BACKGROUND: Clinical trials in cystic fibrosis (CF) have been hindered by the paucity of well characterised and clinically relevant outcome measures. AIM: To evaluate a range of conventional and novel biomarkers of CF lung disease in a multicentre setting as a contributing study in selecting outcome assays for a clinical trial of CFTR gene therapy. METHODS: A multicentre observational study of adult and paediatric patients with CF (>10 years) treated for a physician-defined exacerbation of CF pulmonary symptoms. Measurements were performed at commencement and immediately after a course of intravenous antibiotics. Disease activity was assessed using 46 assays across five key domains: symptoms, lung physiology, structural changes on CT, pulmonary and systemic inflammatory markers. RESULTS: Statistically significant improvements were seen in forced expiratory volume in 1 s (p<0.001, n=32), lung clearance index (p<0.01, n=32), symptoms (p<0.0001, n=37), CT scores for airway wall thickness (p<0.01, n=31), air trapping (p<0.01, n=30) and large mucus plugs (p=0.0001, n=31), serum C-reactive protein (p<0.0001, n=34), serum interleukin-6 (p<0.0001, n=33) and serum calprotectin (p<0.0001, n=31). DISCUSSION: We identify the key biomarkers of inflammation, imaging and physiology that alter alongside symptomatic improvement following treatment of an acute CF exacerbation. These data, in parallel with our study of biomarkers in patients with stable CF, provide important guidance in choosing optimal biomarkers for novel therapies. Further, they highlight that such acute therapy predominantly improves large airway parameters and systemic inflammation, but has less effect on airway inflammation.

Imaging of bone marrow pitfalls with emphasis on MRI.

Normal marrow contains both hematopoietic/red and fatty/yellow marrow with a predictable pattern of conversion and skeletal distribution on MRI. Many variations in normal bone marrow signal and appearances are apparent and the reporting radiologist must differentiate these from other non-neoplastic, benign or neoplastic processes. The advent of chemical shift imaging has helped in characterising and differentiating more focal heterogeneous areas of red marrow from marrow infiltration. This review aims to cover the MRI appearances of normal marrow, its evolution with age, marrow reconversion, variations of normal marrow signal, causes of oedema-like marrow signal, and some common non-neoplastic entities, which may mimic marrow neoplasms.

Diffusion-weighted imaging (DWI) in musculoskeletal MRI: a critical review.

Magnetic resonance imaging (MRI) is the mainstay of diagnosis, staging and follow-up of much musculoskeletal pathology. Diffusion-weighted magnetic resonance imaging (DWI) is a recent addition to the MR sequences conventionally employed. DWI provides qualitative and quantitative functional information concerning the microscopic movements of water at the cellular level. A number of musculoskeletal disorders have been evaluated by DWI, including vertebral fractures, bone marrow infection, bone marrow malignancy, primary bone and soft tissue tumours; post-treatment follow-up has also been assessed. Differentiation between benign and malignant vertebral fractures by DWI and monitoring of therapy response have shown excellent results. However, in other pathologies, such as primary soft tissue tumours, DWI data have been inconclusive in some cases, contributing little additional information beyond that gained from conventional MR sequences. The aim of this article is to critically review the current literature on the contribution of DWI to musculoskeletal MRI.

The imaging of myositis ossificans.

Myositis ossificans (MO) is characterized by abnormal heterotopic bone formation involving striated muscle, tendons, ligaments, fasciae, and aponeuroses. Myocardium, the diaphragm, tongue, larynx, smooth muscle, and sphincters are all spared. Several subtypes of myositis ossificans exist: posttraumatic myositis ossificans (PTMO), nontraumatic/pseudomalignant myositis ossificans, and myositis ossificans progressiva (MOP). This article reviews the clinical features and differential diagnoses of each subtype of MO and illustrates the typical imaging features demonstrated by plain radiography, ultrasound, radionuclide bone scans, computed tomography, and magnetic resonance imaging.

Magnetic resonance imaging of anatomical variations in the knee. Part 2: miscellaneous.

Magnetic resonance imaging is the modality of choice for investigation of internal derangement of the knee. The reporting radiologist must be familiar with both normal anatomy and anatomical variants within the knee, in order to avoid mis-diagnosis, over-investigation and unnecessary intervention. This article reviews the recognised anatomical variants of the non-ligamentous/musculotendinous structures of the knee, their anatomy, incidence and typical appearances on MRI.

Magnetic resonance imaging of anatomical variations in the knee. Part 1: ligamentous and musculotendinous.

Magnetic resonance imaging (MRI) is now the modality of choice for the investigation of internal derangement of the knee. Technological advances, including the wider availability of stronger magnets and new sequences, allows improved visualisation of smaller structures. Normal variants must be recognised as such, so that both over-investigation and mis-diagnosis are avoided. This article reviews both the well-recognised and the less common ligamentous and musculotendinous anatomical variants within the knee and illustrates their imaging characteristics on MRI.

A novel ceramic coating for reduced metal ion release in metal-on-metal hip surgery.

An ovine total hip arthroplasty model was developed to evaluate metal ion release, wear, the biological response and adverse tissue reaction to metal-on-metal (MoM) bearing materials. The performance of an advanced superlattice ceramic coating (SLC) was evaluated as a bearing surface and experimental groups divided into; (1) MoM articulating surfaces coated with a SLC coating (SLC-MoM), (2) uncoated MoM surfaces (MoM), and (3) metal on polyethylene (MoP) surfaces. Implants remained in vivo for 13 months and blood chromium (Cr) and cobalt (Co) metal ion levels were measured pre and postoperatively. Synovial tissue was graded using an ALVAL scoring system. When compared with the MoM group, sheep with SLC-MoM implants showed significantly lower levels of chromium and cobalt metal ions within blood over the 13-month period. Evidence of gray tissue staining was observed in the synovium of implants in the MOM group. A significantly lower ALVAL score was measured in the SLC-MoM group (3.88) when compared with MoM components (6.67) (p = 0.010). ALVAL results showed no significant difference when SLC-MOM components were compared to MoP (5.25). This model was able to distinguish wear and the effect of released debris between different bearing combinations and demonstrated the effect of a SLC coating when applied onto the bearing surface. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1760-1771, 2019.

Midfoot and hindfoot bone marrow edema identified by magnetic resonance imaging in feet of subjects with diabetes and neuropathic ulceration is common but of unknown clinical significance.

OBJECTIVE: We conducted a retrospective cohort study assessing the prevalence and clinical and radiological outcome of remote areas of bone marrow edema on magnetic resonance imaging (MRI) in the feet of subjects with diabetes and neuropathic foot ulceration. RESEARCH DESIGN AND METHODS: MRIs performed over 6 years looking for osteomyelitis associated with neuropathic lesions were assessed for remote areas of signal change. RESULTS: Seventy MRI studies were assessed. Remote areas of signal change were present in 21 (30%) subjects, involved midfoot or hindfoot in 20 subjects, were associated with younger age and renal replacement therapy, and did not predict future Charcot neuroarthropathy or infection at that site. Repeat MRIs in 11 subjects with such areas found that none had progressed, six had improved, and two had resolved; in 29 subjects without such areas, five had developed new areas. CONCLUSIONS: Bone marrow edema in the midfoot and hindfoot of subjects with diabetes and neuropathic lesions is common, often transient, and of unknown significance.