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[Correlative factors of secondary fracture after percutaneous kyphoplasty for osteoporotic vertebral compression fracture].

OBJECTIVE
To analyse the correlative factors of secondary vertebral fracture after percutaneous kyphoplasty (PKP) in treatment of osteoporotic vertebral compression fracture (OVCF) at different levels (adjacent and/or nonadjacent levels).


METHODS
Between December 2002 and May 2008, 84 patients with OVCF were treated with PKP, and the clinical data were analysed retrospectively. There were 11 males and 73 females with an average age of 70.1 years (range, 55-90 years). All patients were followed up 24-96 months (mean, 38 months). Secondary vertebral fracture occurred in 12 cases at 3-52 months after PKP (secondary fracture group), no secondary fracture in 72 cases (control group) at over 24 months. The preoperative bone mineral density, postoperative vertebral height compression rate, postoperative Cobb angle, amount of injected bone cement per vertebra, puncture pathway (uni- or bilateral puncture), age, gender, number of fracture segment, and cement intradiscal leakage were compared between 2 groups to find correlative factors of secondary vertebral fractures.


RESULTS
There was no significant difference in preoperative bone mineral density, postoperative vertebral height compression rate, postoperative Cobb angle, amount of injected bone cement per vertebra, puncture pathway, age, gender, and number of fracture segment between 2 groups (P > 0.05). But the incidence of cement intradiscal leakage was much higher in secondary fracture group than in control group (chi2 = 5.294, P = 0.032).


CONCLUSION
Cement intradiscal leakage may be the correlative factor of secondary vertebral fracture after PKP in OVCF.