Secondary thoracolumbar deformity and sagittal imbalance due to osteoporosis in a young man with Cushing's disease: A case report.

INTRODUCTION

To describe an unusual case of Cushing's disease with spontaneous axial pain due to multiple consecutive vertebral fractures which led to secondary deformity that required surgical treatment.

PRESENTATION OF CASE: A 43-year-old man was referred to our service with back pain without previous trauma. He was diagnosed of refractory arterial hypertension and we observed centripetal obesity during exploration. With clinical findings and laboratory studies, ACTH-dependent Cushing's syndrome due to a pituitary microadenoma was diagnosed and the patient underwent an endoscopic-assisted endonasal transsphenoidal resection. Dual energy X-ray absorptiometry (DXA) revealed spine and hip osteoporosis. Moreover, X-ray, MR and CT showed multiple vertebral osteoporotic compression fractures in thoracic and thoracolumbar area. Secondary kyphosis thoracolumbar deformity and sagittal imbalance was treated by two-level Smith-Petersen osteotomies (SPO) and instrumented posterolateral arthrodesis T10-L3 using fenestrated pedicles screws with polymethyl methacrylate (PMMA). At six years of follow-up dual energy X-ray absorptiometry (DXA) recovered normal values (T-score lumbar spine L2-L4 1.4 and T-score hip -1.9) and X-ray study showed an adequate sagittal vertebral axis.

DISCUSSION: Osteoporosis is a common feature of CD and fractures occur in 30-50% of cases. Treating the underlying cause reduces the risk of new fractures. Medical therapy is usually enough but consecutive multiple vertebral fractures related to glucocorticoid excess may lead to secondary painful deformity.

CONCLUSION

Vertebral compression fractures result from secondary corticoid-induced osteoporosis in Cushing's disease. Early detection and treatment of primary disease decreases the risk of new fractures. However, unusual secondary spinal deformity or disability may require surgery.