Ultra sonographic findings for chronic lateral epicondylitis.

PURPOSE: To assess which individual gray-scale and color Doppler US findings and their combination are strongly associated with lateral epicondylitis. Also to determine whether chronic lateral epicondylitis is possible without any positive US findings. METHODS: 49 patients (6 bilateral) underwent gray-scale ultrasonic imaging between 2005 to 2007. All had a history of lateral epicondylitis and had concordant pain during US probe compression in the common extensor region. Mean patient age was 47 (sd 7.7) years; M/F ratio 21/28; L/R ratio 17/32. Five symptom free volunteers (all bilateral) with a mean age of 36 (sd 8.7) years; M/F = 4/6; L/R = 5/5. RESULTS: Neovascularity determined by color Doppler and four gray-scale US findings - a convex external contour, an erosive lateral epicondular cortex, internal calcifications, or a tear - have a specificity and PPV of 100% with conclusive likelihood ratios. However, only the sensitivity for neovascularity is above 50%. A combination of gray-scale and color Doppler shows a sensitivity between 92% to 100%, a 90% specificity with a 98% PPV and a high likelihood ratio (9 to 10). CONCLUSION: The combination of gray-scale and color Doppler changes is diagnostically superior to identify chronic lateral epicondylitis. Signs which confirm the diagnosis are a convex boundary, an erosive cortex, internal calcifications, a tear, and neovascularity. Patients with positive clinical signs and concordant pain but no US findings require further MRI evaluation.

Regional migratory osteoporosis in a patient with ankylosing spondylitis.

We report the first case of regional migratory osteoporosis (RMO) in a patient with ankylosing spondylitis (AS). This middle-aged man suffered from an acute onset of knee pain that increased on weight bearing, followed by ankle pain. The diagnosis of RMO was confirmed using magnetic resonance imaging (MRI), after exclusion of other causes of knee pain. MRI revealed a large area of bone marrow oedema without a zone of demarcation or subchondral fracture with a demonstration of shifting marrow oedema on the follow-up MRI scan from the medial femur condyl to the tibia plateau lateral and then to the distal tibia epiphysis. Treatment with the bisphosphonate ibandronate, however, was unsuccessful. RMO is characterized clinically by migrating arthralgia of the weight-bearing joints of the lower limbs, mainly in middle-aged males. Although the aetiology is unknown, the pathophysiology of RMO seems to be closely related to transient osteoporosis of the hip (TOH), which has been considered a reversible stage of avascular necrosis of the hip (AVN). There is no causal treatment for RMO. Avoidance of weight bearing and use of analgesics are effective in reducing symptoms. The combination of RMO and AS yielded diagnostic difficulties, as the clinical picture and the marrow oedema seen on MRI could be attributed to several AS-related causes such as enthesitis, early stadium of arthritis, osteonecrosis, or sterile osteomyelitis.

CT density measurement of bone graft within an intervertebral lumbar cage: increase of hounsfield units as an indicator for increasing bone mineral content.

Radiographic assessment of lumbar interbody fusion is difficult, especially in the presence of cages and metal artifacts. The purpose of this study is to assess whether impacted bone chips in intervertebral lumbar cages show a tendency toward increased attenuation on postoperative computed tomography (CT) scans as a sign of ongoing revascularization and increased bone mineral content inside the cage. Twenty-one patients with single- or double-level lumbar fusion underwent CT scanning 1-44 months postoperatively. CT attenuation of bone inside the cage was measured with Hounsfield units. Intra- and interobserver variability were evaluated. Regression analysis showed an increase of 7.5 HU/month postoperatively for an initial value of 615 HU. Intra- and interobserver variability showed an interclass coefficient of 0.97. CT attenuation of bone graft inside an intervertebral cage increases in the postoperative period. Hounsfield unit measurement can be performed with a high degree of accuracy and reproducibility and may in the future provide a useful tool in studying cage contents in individual patients.