Obturator Externus Bursitis: Cases report

The obturator externus bursa has been described as a potential bursa between the tendon of the obturator externus muscle and the posterior hip capsule. Although pathologic involvement of the iliopsoas bursa by intraarticualr hip disease has been extensively described, obturator externus bursa has not been fully investigated. We describe a patient who presented with hip pain and limited range of motion. Her magnetic resonance imaging of pelvis revealed an enhancing cystic lesion that extends inferomedially displacing obturator externus muscle and mild synovitis of the right hip. She was diagnosed as having obturator externus bursitis, and after symptomatic treatment pain and limited range of motion disappeared. The obturator externus bursa is a potential communication of the hip joint, can be a site of disease spread from the hip joint, and can be identified with magnetic resonance imaging.

HLA-B27 Positive and HLA-B27 Negative Ankylosing Spondylitis: A Comparative Study in Diagnostic Process and Clinical Features

OBJECTIVE: To investigate the differences in clinical and radiologic features between HLA-B27 positive ankylosing spondylitis (AS) and HLA B27 negative AS METHOD: Ninety-nine consecutive patients who were suspected as AS in initial diagnostic process were studied. HLA-B27 was examined with microlymphocytotoxicity method in all patients. A radiologist and a physiatrist re- read plain pelvis radiographies of all patients. Difference in onset age and C-reactive protein (CRP) depending on HLA B27 status and an association between HLA B27 status and clinical and radiologic features were tested. RESULTS: Sacroiliitis (> or =bilateral grade 2) was identified in 63 of 77 patients with HLA B27 and 7 of 22 patients without HLA B27 through the re-reading process. Ten percent of definite AS was HLA B27 negative AS. Five of 22 patientswithout HLA B27 were diagnosed as diffuse idiopathic skeletal hyperostosis. There was a significant association between sacroiliitis (> or =bilateral grade 2) and HLA B27 (p or =unilateral grade 1). None of clinical and radiologic parameters are associated with HLA B27 status. It does not make difference in onset age of AS. To make a more concrete conclusion, a study of a much larger number of HLA B27 negative AS patients will be necessary.

Biomechanical Adjustments in Lumbar Spine Associated with Sudden Upper Limb Loading

OBJECTIVE: To investigate the response of back muscle, the flexion moment and the kinematic change of lumbar spine during sudden upper limb loading between expected and unexpected conditions. METHOD: 23 healthy young subjects (13 male and 10 female, mean age 26.6+/-3.3) were recruited. We measured the latency of paraspinal muscle contraction (erector spinae and lumbar multifidus), flexion moment of lumbar spine, and kinematic change of lumbar spine during sudden upper limb loading by using surface EMG system, motion analysis system, and force platform. 6 trials with 3 eye opened and 3 eye closed were performed randomly. RESULTS: The latency of paraspinal muscle contractions was significantly slower during eyes closed condition than during eyes opened condition after sudden upper limb loading (p<0.05). The flexion moment and the flexion change of lumbar spine increased significantly during eyes closed condition compared with eyes opened condition (p<0.05). CONCLUSION: The response of paraspinal muscle was significantly slower and the flexion moment and the flexion change of lumbar spine was higher during unexpected condition than during expected condition after sudden upper limb loading. Therefore, the spinal stability is more decreased during unexpected condition than expected condition.