A new method for investigating osteoarthritis using Fast Field-Cycling nuclear magnetic resonance.

Osteoarthritis in synovial joints remains a major cause of long-term disability worldwide, with symptoms produced by the progressive deterioration of the articular cartilage. The earliest cartilage changes are thought to be alteration in its main protein components, namely proteoglycan and collagen. Loss of proteoglycans bound in the collagen matrix which maintain hydration and stiffness of the structure is followed by collagen degradation and loss. The development of new treatments for early osteoarthritis is limited by the lack of accurate biomarkers to assess the loss of proteoglycan. One potential biomarker is magnetic resonance imaging (MRI). We present the results of a novel MRI methodology, Fast Field-Cycling (FFC), to assess changes in critical proteins by demonstrating clear quantifiable differences in signal from normal and osteoarthritic human cartilage for in vitro measurements. We further tested proteoglycan extracted cartilage and the key components individually. Three clear signals were identified, two of which are related predominantly to the collagen component of cartilage and the third, a unique very short-lived signal, is directly related to proteoglycan content; we have not seen this in any other tissue type. In addition, we present the first volunteer human scan from our whole-body FFC scanner where articular cartilage measurements are in keeping with those we have shown in tissue samples. This new clinical imaging modality offers the prospect of non-invasive monitoring of human cartilage in vivo and hence the assessment of potential treatments for osteoarthritis. Keywords: Fast Field-Cycling NMR; human hyaline cartilage; Osteoarthritis; T1 dispersion; quadrupolar peaks; protein interactions.

Anatomical study of the human sacral hiatus and implications for successful caudal epidural injection.

BACKGROUND: Caudal epidural injection (CEI) is a commonly used procedure to treat back and leg pain secondary to nerve root irritation, predominantly in the context of spinal canal stenosis. Key to a successful outcome is correct needle placement. Although fluoroscopic guidance confirms accurate needle placement, it does not help in determining the starting point, which can lead to multiple needle insertions. OBJECTIVE: This study aimed to determine the variability in size and position of the sacral hiatus and to identify reproducible surface landmarks to locate its position. METHODS AND STUDY DESIGN: 250 human sacral bones were examined, measuring morphology and structure. Vernier callipers accurate to 0.1 mm were used for measurements. Results were analysed using SPSS statistical software. RESULTS: Two specimens were excluded due to agenesis of the hiatus (0.8%). Of the remaining 248 specimens, it was found that the mean internal diameter of the sacral hiatus was 5.12 mm (SD 1.61). The position of the hiatus was variable but was most commonly found at the level of the fourth sacral vertebrae (62.9%, n = 156). Mean distance between the two superolateral sacral prominences was 64.15 mm (SD 6.5) and between superolateral sacral prominences (left and right) and apex of the hiatus were 63.21 mm (SD 10.9) and 63.34 mm (SD 10.87) respectively. CONCLUSION: Although there is a clear anatomical variance in the position and size of the sacral hiatus, this study suggests that surface anatomy landmarks can be used to form an equilateral triangle of which the inferior apex should correspond to the sacral hiatus. Knowledge of this surface anatomy may assist the correct location of the sacral hiatus and hence subsequently improve the efficacy of CEI.

Utility of follow-up radiographs in conservatively managed acute fifth metatarsal fractures.

Fifth metatarsal fractures are the most common fracture of the foot, with the majority being managed conservatively. A variety of treatment methods are described in the literature. Follow-up radiographs are taken to identify fracture displacement, and subsequently to assess for bony union throughout treatment. We assessed the utility of serial radiographic assessment in management of these fractures. Clinical notes and radiographs of 79 patients with fifth metatarsal fractures were analysed retrospectively. Serial radiographs were studied to identify displacement and the last X-ray was reviewed for evidence of fracture union. 96% of fractures were managed conservatively. 29% showed radiological healing at last clinic visit, the rest being discharged as were considered clinically healed. Similar fracture types were managed differently. 3 fractures were surgically treated after failed conservative management. 1 fracture showed displacement from initial radiographs, and was successfully managed conservatively. Without clear guidelines, these injuries are managed differently from a radiological perspective. Follow-up radiographs taken before 6-8 weeks do not appear to alter patient management. Based on the current study we present our recommendations for radiographic assessment of acute fifth metatarsal fractures.