An unusual cause of back pain in osteoporosis: lessons from a spinal lesion.

Case report A 77 year old woman was admitted with a three month history of worsening back pain, malaise, and anorexia. On direct questioning, she reported that she had suVered from back pain for four years. The thoracolumbar radiograph four years earlier showed T6/7 vertebral collapse, mild scoliosis, and degenerative change of the lumbar spine (fig 1); but other investigations at that time including the erythrocyte sedimentation rate (ESR) and protein electophoresis were normal. Bone mineral density then was 0.914 g/cm (T score = −2.4) at the lumbar spine, 0.776 g/cm (T score = −1.8) at the right femoral neck and 0.738 g/cm (T score = −1.7) at the left femoral neck. She was given cyclical etidronate after this vertebral collapse as she had suVered a previous fragility fracture of the left wrist. On admission, she was afebrile, but general examination was remarkable for pallor, dental caries, and cellulitis of the left leg. A pansystolic murmur was heard at the cardiac apex on auscultation; there were no other signs of bacterial endocarditis. She had kyphoscoliosis and there was diVuse tenderness of the thoracolumbar spine. Her neurological examination was unremarkable. Laboratory investigations showed a marked normocytic anaemia (Hb, 6.6 g/dl, MCV, 80 fl), leucocytosis (TLC, 19.9 × 10/l, neutrophils, 12.1), ESR of 45 mm 1st hour, and C reactive protein (CRP) of 89.9 mg/l (normal<6 mg/l). There was polyclonal increase of immunoglobulin; biochemical profile and urine analysis were normal. Blood cultures grew Streptococcus mitis (alpha-haemolytic) and an echocardiogram showed a large vegetation on the posterior mitral leaflet, confirming the clinical suspicion of bacterial endocarditis. After microbiological review, she was given intravenous teicoplanin (because of penicillin allergy) and netilmycin. A blood transfusion was also arranged. The back pain gave cause for concern as she found it diYcult to turn in bed. New radiographs showed an increase in the scoliosis, besides the previously recorded vertebral deformities (T6/7) and degenerative change. Technetium (Tc) scintigraphy showed increased uptake in the thoracolumbar spine, consistent with osteoporosis and osteoarthritis. She was treated with opioid analgesics and subcutaneous calcitonin injections and supported with a corset. In the fourth week of her inpatient stay, she suddenly developed weakness of the legs, loss of sensation up to T8, and incontinence. Magnetic resonance imaging Figure 1 Lateral radiograph of the thoracic spine showing T6/7 vertebral collapse. Ann Rheum Dis 1999;58:327–331 327