Clinical relevance of pain patterns in osteoporotic vertebral compression fractures.

Few studies have been conducted to explain the pain patterns resulting from osteoporotic vertebral compression fractures (OVCF). We analyzed pain patterns to elucidate the pain mechanism and to provide initial guide for the management of OVCFs. Sixty-four patients underwent percutaneous vertebroplasty (N=55) or kyphoplasty (N=9). Three pain patterns were formulized to classify pains due to OVCFs: midline paravertebral (Type A), diffuse paravertebral (Type B), and remote lumbosacral pains (Type C). The degree of compression was measured using scale of deformity index, kyphosis rate, and kyphosis angle. Numerical rating scores were serially measured to determine the postoperative outcomes. As vertebral body height (VBH) decreased, paravertebral pain became more enlarged and extended anteriorly (p<0.05). Type A and B patterns significantly showed the reverse relationship with deformity index (p<0.05), yet Type C pattern was not affected by deformity index. Postoperative pain severity was significantly improved (p<0.05), and patients with a limited pain distribution showed a more favorable outcome (p<0.05). The improvement was closely related with the restoration of VBH, but not with kyphosis rate or angle. Thus, pain pattern study is useful not only as a guide in decision making for the management of patients with OVCF, but also in predicting the treatment outcome.