Spontaneous Epidural Hematoma at the Lumbar Facet Joint: A Case Report

Spontaneous epidural hematomas (SEHs) of the lumbar spine are rare. The pathogenesis is not entirely clear, but several reports have suggested that bleeding originating in the venous epidural plexus is the cause. This is the second report of a SEH thought to be the result of facet joint hemorrhage with no previous synovial cyst formation. A magnetic resonance image revealed a mass beginning in the left epidural space and continuing through to the left L5-S1 facet joint. Surgically, the epidural hematoma, which was covered by a very thin translucent membrane, was visualized directly. A histopathological examination revealed the wall of the epidural hematoma to be composed of very thin fibrous connective tissue with no synovium lining. The purpose of this study was to report a case of an epidural hematoma originated from lumbar facet joint, diagnosed by radiological examination, and to present a review of the subject literature.

Radiologic Findings of Hemophilic Arthropathy of the Knee: Focusing on MR Imaging & Plain Radiography

PURPOSE: To evaluate the characteristic MR findings of hemophilic arthropathy of the knee. MATERIALS & METHOD: Seven knees in six patients with hemophilia (five hemophilia A and one hemophilia B) were retrospectively studied with MR images and plain radiographs. Patients were aged between 2 and 20 years (mean, 11) and all had a clinical history of repeated hemarthrosis. MR images of the knee were analyzed with respect to intra- andextra-articular hemorrhage, the state of synovial tissue, articular cartilage, bone, menisci, and ligaments. RESULTS: Synovial hypertrophy and articular cartilage destruction were revealed in all seven knees ; pannus wasfound in four, and was seen as low signal intensity on T1-weighted image and high signal intensity on T2-weighted images. All five instances of synovial hypertrophy and pannus were enhanced. Joint effusion, presented in five ofseven knees, demonstrated slightly low signal intensity on T1-weighted image and high signal intensity on T2-weighted images, and was associated with peripheral low signal intensity of hemosiderin. Subchondral and marginal erosion was seen in six cases, patellar deformity in three, meniscal damage in four and cruciate ligament damage in one case. CONCLUSION: MR is superior to plain radiography in demonstrating chronic repeated hemarthrosis (manifested as thick intra-articular effusion), hemosiderin, synovial hypertrophy, erosion ordestruction of articular cartilage and bone, and meniscal or cruciate ligament injury of hemophilic arthropathy ofthe knee. MR is therefore thought to be a useful imaging study for accurate evaluation of hemophilic arthropathyof the knee.