Sciatic nerve: beyond the sacral foramen

Sciatica may result from pathologies affecting the nerve both in its intraspinal and extraspinal course. In daily routine, the vast majority of cases are caused by herniation of the lumbar discs compressing the neural roots. Extraspinal causes of sciatic pain are usually underestimated and the imaging study may be completed after reporting the lumbar MRIs. However, early diagnosis of the exact etiology of sciatica is paramount for both relieving the symptoms and preventing any additional neurologic injury. In this pictorial assay, some relatively rare causes of sciatic neuralgia along the route of the sciatic nerve after leaving the sacral foramen will be displayed

The peroneus brevis tendon at its insertion site on fifth metatarsal bone

Background: The differences at the attachment site of peroneus brevis (PB) to the fifth metatarsal bone isimportant in terms of the forces exerted on the bone and hence the mechanism of fractures involving thisstructure. In this study, we investigated the anatomical properties of PB at the insertion site to the base offifth metatarsal bone, its possible intertendinous connections with peroneus tertius (PT) and theirpossible effects on the fracture occurrence at the bony attachment site.Methods: The length and the width of PB tendons at their mid- and end-points were measured andclassified according to the insertion types. Besides, the length and the width of the base of fifth metatarsalbone were assessed. The slips extending from the PB tendons and their relationship with PT were alsoevaluated. The data was compared statistically with each other and between the right and left sides.Results: The length of PB tendon was measured 79.57 15.40 mm on the right side; 81.48 14.31 mm on theleft. The width of PB tendon at the mid-point was 4.46 0.80 mm on the right side; 4.42 0.94 mm on the left.The width of the tendon at its insertion point was measured 14.85 3.40 mm and 15.16 3.42 mm on the rightand left sides respectively. PB was divided into three types according to its attachment to base of fifth metatarsalbone (5thMB). Type I, Type II and Type III were observed at the rates of 59.5%, 28.6% and 11.5% respectively. It wasobserved that the slips to the bone were extending more commonly from PB than from PT and that the largemajority of them were single having their insertions on the base of the proximal phalanx of the fifth toe.Conclusions: Knowing the width and insertional types of PB aids in understanding the mechanism offractures at the site of bony attachment. The existence of slips may help the surgeon in the proceduresinvolving PB or the lateral side of the forefoot

Carpal bone cysts: MRI, gross pathology, and histology correlation in cadavers

PURPOSEIntraosseous cysts of carpal bones are frequently observed on routine imaging examinations of the wrist. There is controversy regarding the underlying pathogenesis of these cysts. In this study, we aimed to investigate the magnetic resonance imaging (MRI) appearance of intracarpal bone cysts in correlation with histologic analysis, using cadaveric wrists.METHODSFive freshly frozen cadaveric wrist specimens (from three women and two men; mean age at death, 80 years) were studied. Imaging was performed with T1-weighted fast spin-echo, and proton density-weighted fast spin-echo with and without fat-suppression. The existence of cysts was confirmed by comparing MRI and histology findings. Hematoxylin and eosin stain was performed on tissue slices of 3 mm thickness to analyze the structure of cysts and their communication with the joint cavity.RESULTSTen cysts were observed. In all cases, cysts were eccentrically located either in the subchondral bone or beneath the cortex. On histologic examination, there were regions of fat necrosis without inflammation or increased vascularity, surrounded by fibrous walls. There were no giant cells, cholesterol granules, or a true synovial lining. Mucoid change was rare. Fibrous component of cysts varied from small fibrous septa to well-formed walls. Some cysts communicated with the joint cavity. Two cysts were adjacent to ligamentous attachments. Those cysts with fibrous tissue demonstrated variable hypointensity on T2.CONCLUSIONIn contrast to previous reports that described a mucoid composition of intracarpal bone cysts with occasional foamy macrophages, our observations support the concept that these lesions reflect a spectrum of fat necrosis and fibrous changes, without inflammation or hypervascularity. These cysts are typically surrounded by fibrous walls without a true synovial lining

Pelvic Hydatid Disease: CT and MRI Findings Causing Sciatica

Pelvic masses, especially hydatid disease, rarely present with sciatica (1, 2). We present the computed tomography (CT) and the magnetic resonance imaging (MRI) findings of a 49-year-old female patient with presacral hydatid disease, who was evaluated for her sciatica. We also want to emphasize the importance of assessing the pelvis of patients with symptoms and clinical findings that are inconsistent and that cannot be satisfactorily explained by the spinal imaging findings

Computer-assisted diagnosis of osteoartrithis on hip radiographs

Hip osteoarthritis (OA) can be highly disabling and eventually may necessitate total replacement of the joint. Studies with computer-based analysis of the hip OA may give new insight both in imaging and clinical evaluation of the disease. In this study, new acetabular angle measurement methods of femoral head-neck-shaft angle (CCD), center-edge angle (CE) and acetabular depth-to-width ratio (ADR) are reconstructed via a computer based analysis technique for robust detection of OA on anteroposterior (AP) hip radiographs. The evaluation and validation of this computer-assisted system is performed by comparing these new automated methods with those of traditional manual measurement methods done by one orthopaedist and one radiologist. The 50 adult hip AP radiographs with OA are used and overall measurements are produced for both sides of the hip on radiographs separately. The mean average difference between these two measurement methods for CCD angle is found 1 degrees +/- 1,2 degrees, for CE angle 1 degrees +/- 1,5 degrees and for ADR ratio 1 +/- 1,4 respectively. The results show that this new automated angle and ratio measurement system can be found feasible and user friendly by clinicians owing to the similarity between the comparative results of two measurement methods statistically

Osteopoikilosis coexistent with ankylosing spondylitis and familial Mediterranean fever

Osteopoikilosis (OPK) is a rare benign sclerosing disease of the skeleton and inherited as an autosomal dominant trait. OPK is associated with inflammatory rheumatic disorders, such as rheumatoid arthritis, scleroderma, reactive arthritis and familial Mediterranean fever (FMF). We report a rare case of OPK coexistent with ankylosing spondylitis and FMF. The patient presented multiple sclerotic lesions within and around the sacroiliac joints and a series of radiological diagnostic challenges