Adjacent level fracture after osteoporotic vertebral compression fracture: a nonrandomized prospective study comparing balloon kyphoplasty with conservative therapy

Abstract

In literature, there are conflicting clinical data regarding the incidence of subsequent fracture after balloon kyphoplasty (BK); moreover, the risk of adjacent vertebral fractures has not been well established because there are limited comparative data available with conservatively treated control groups. The purpose of this prospective nonrandomized comparative study was to analyze the incidence and possible risk factors of adjacent level fracture comparing BK with conservative therapy. Consecutive patients satisfying the inclusion criteria of acute vertebral fracture pain (occurring within 1-6 weeks of the event and not relieved by oral analgesia) and imaging criteria of acute fracture activity were enrolled. All patients meeting the inclusion criteria were offered BK. The patients who declined BK and agreed to longitudinal evaluation were treated conservatively and constituted the control group. In 3 out of 46 patients (6.5%) treated with BK and in 10 out of 61 patients treated conservatively (16.4%), the adjacent level fracture occurred within 1 year. The degree of local kyphosis and bone mineral density (BMD) were identified as important predictive factors for adjacent level fracture. These results indicated that BK carries a low risk of adjacent level fractures. Lower BMD values and altered biomechanics in the treated area of the spine due to resistant kyphosis are possible predictive factors for adjacent level fractures. A positive effect of BK over conventional treatment was observed upon reduction of the incidence of adjacent level fracture, vertebral morphology, and pain reduction.