Clinical And Biomechanical Study Of Vertebroplasty For Osteoporotic Vertebral Compression Fractures

BackgroudOsteoporotic vertebral compression fractures is the most common types of osteoporosis seen in patients.Percutaneous vertebroplasty(PVP)is widely used in the treatment of osteoporotic vertebral compression fractures because of its good analgesic effect.At present,PVP with unilateral or bilateral pedicle approach is controversial,mainly due to unilateral pedicle approach PVP of clinical efficacy and safety are questioned.At the same time,the findings of postoperative new fractures reports gradually increased,and also the relevant risk factors and biomechanical studies have no clear conclusions.Materials and methods1.Comparison of clinical efficacy of unilateral and bilateral vertebral pedicle approach PVP in the treatment of osteoporotic vertebral compression fractures.The clinical data of patients with single-segment osteoporotic vertebral compression fractures were analysed retrospectively.According to the different approach,the patients were divided into unilateral pedicle approach group and bilateral pedicle approach group.The clinical efficacy,operation timer,bone cement injection volume,incidence of cement leakage,degree of vertebral height restoration,and degree of kyphosis correction were compared.2.Clinical study of vertebroplasty in the treatment of Kummel's disease.The clinical data of patients with Kummel's disease undergoing percutaneous vertebroplasty via unilateral or bilateral approach.The clinical efficacy,operation timer bone cement injection volume,incidence of cement leakage,degree of vertebral height restoration,and degree of kyphosis correction were compared between the patients receiving surgery via the two approaches.3.Analysis of risk factors related to new vertebral fracture after vertebroplasty.The clinical data of patients with osteoporotic vertebral compression fractures treated by vertebroplasty in our hospital were investigated and analyse the related risk factors of non-surgical vertebral new fractures after PVP.4.Biomechanical study of adjacent vertebral body after vertebroplasty.Take the embalmed cadaver thoracolumbar specimen as research object.The fracture model was established in lumbar one vertebrae,the stiffness and the strain of the adjacent vertebral body and intervertebral disc were measured in different states.Results:1.Comparison of clinical efficacy of unilateral and bilateral vertebral pedicle approach PVP in the treatment of osteoporotic vertebral compression fractures.The unipedicular group incurred significantly shorter operation time(36.4 ±6.0 min)and significantly less bone cement voluble injected(3.7±1.1 ml)than the bipedicle group(52.9±6.8 min and 4.3-1.1 ml respectively,P<0.05).There were no significant differences between the 2 groups in anterior vertebral height restoration middle vertebral height restoration or kyphosis correction(P>0.05).The VAS scores at 24 hours,3 and 1 2 months post operation were significantly lower than pre operation in both groups(P<0.05),but there were no such significant differences between the 2 groups(P>0.05).The cement leakage rate for the unipedicular group(28.9%)was insignificantly lower than that for the bipedicle group(46.4%,P>0.05).2.Clinical study of vertebroplasty in the treatment of Kummel's disease,The operation time was shorter in the unipedicular group than in the bipedicle group(P<0.05),but bone cement injection volume,incidence of cement leakage,degree of anterior vertebral height restoration,degree of middle vertebral height restoration,degree of kyphosis correction,and VAS scores were all comparable between the two groups(P>0.05).In both groups,the VAS scores at 24 h,3 months and at the last follow-up after the surgery were lowered compared to the preoperative scores(P<0.05).3.Analysis of risk factors related to new vertebral fracture after vertebroplasty.A total of 182 patients met the inclusion criteria.There were 155 female and 27 male patients with a mean age of 69.7 years(range 49-91 years).The follow-up period was 24-50 months(average 26.4 months).A total of 294 VCFs among 182 patients were observed,28 new VCFs occurred in 21 patients(11.5%)during the follow-up period.Statistical analysis indicated that higher BMI and a greater number of initial symptomatic fractures were significantly associated with new VCFs after PVP(P<0.05).4.Biomechanical study of adjacent vertebral body after vertebroplasty.The average amount of bone cement was 4.4 ml(3.8-5.0ml).The stiffness of after augmentation(201 ±65 N/mm)was significantly higher than the stiffness of post-fracture(96±24 N/mm,P<0.05),but still lower than pre-fracture stiffness(242± 67 N/mm,P<0.05).After augmentation,the adjacent vertebral of strain rate was no significant difference(P>0.05)with pre-fracture.The strain of the adjacent the upper vertebral body after injection of bone cement was not significantly different from that before fracture(P>0.05),while the strain of adjacent the lower vertebral body was significantly higher than that before fracture(P<0.05).Conclusion:1.Unilateral and bilateral pedicle approach of PVP can achieve similar clinical results.2.Vertebroplasty for the treatment of Kummel's disease,unilateral puncture can achieve similar clinical results.3.BMI and number of initial symptomatic fractures were risk factors of new vertebral fracture after vertebroplasty4.The segmental stiffness could not be restored to the initial level,but the load sharing of the inferior vertebral body was changed.