[Objective]To compare the difference between single and double balloon kyphoplasty to treat osteoporotic vertebral body.[Method]Twenty osteoporotic vertebral bodies were harvested from 10 embalmed cadavers,alternatingly assigned to either the single and double group.All vertebraes were compressed by 25% of their initial height using materials testing machine to create vertebral compression fractures and determine their augmented strength and stiffness before and after injecting the cement.Precompression,postcompression and posttreatment height of vertebrae were measured.[Result]Both treatments resulted in significantly stronger vertebral bodies relative to their initial state(P

Objective To evaluate the clinical efficacy and safety of kyphoplasty with single balloon cross-midline expansion using unipedicular approach for osteoporotic vertebral body compressive fracture (OVCF).Methods Thirty six cases of painful OVCF were included in the study,with 61 vertebrae involved.Under X-ray fluoroscopy monitoring,kyphoplasty was performed using a unilateral,single,balloon via a unilateral transpedicular approach.A final balloon position was in the midline of the vertebral body with the balloon cross-midline expansions and bone cement filled. Clinical outcomes were determined by comparison of preoperative and postoperative VAS and ODI scores.Radiographic assessment included vertebral height restoration and correction of kyphosis.Follow-up was conducted for 6.0-12.0 months(mean 9.2 months).Results Thirty-six consecutive patients with 61 vertebrae were successfully operated with an operative time of(37.4±9.6)rain per vertebra.All patients had significant pain relief and functional recovery within 96 h after the procedure with no surgery-and device-related complications.VAS score improved from(7.3±1.0)preoperatively to(2.7±0.8)postoperatively(t=19.53,P＜0.01).ODI score was decreased from(71.1±10.9)%preoperatively to(26.6±6.4)%postoperatively(t=18.54,P＜0.01).The average anterior body height loss was(14.3±2.8)mm before procedure and(10.0±1.8)mm after procedure(t=14.68,P＜0.01).The average middle body height loss was(10.2±2.7)mm before procedure and(5.9±1.8)mm after procedure(t=16.44,P＜0.01).The Cobb's angle was corrected from 23.4°±5.0° to 16.2°±2.8°(t=15.60,P＜0.01).Some leakages of cement around the anterior margin of vertebra and inter-vertebral space were found in 2 patients,but there were no clinical symptoms.X-ray examination indicated there were no cement leakages in other vertebra.The pain relief and functional recovery were substantial and maintained to the last follow up without any re-collapse or adjacent level fracture.Conclusions A single-balloon cross-midline expansion using unipedicular approach in kyphoplasty for OVCF is effective and safety,less operation time,less radiation exposure compared to the conventional kyphoplasty technique.

BACKGROUND: In kyphoplasty procedure, two balloons are inserted into the vertebral body and inflated simultaneously for height symmetric restoration of the vertebral body. However, the expensive cost of balloon of kyphoplasty limits the extensive development of this procedure in developing countries. In this study, we try to inflate single balloon with bilateral transpedicular routes alternatively to achieve vertebral body height balanced restoration and reduce operation expenditure. But biocompatibility of bone cement and effect of kyphoplasty still need further observation.OBJECTIVE: To investigate the biocompatibility of bone cement and the clinical efficacy of bipedicular kyphoplasty for osteoporotic vertebral compression fractures by inserting single inflatable balloon into injured vertebral body and filling bone cement in the cavity caused by inflating balloon via bipedicular approach.DESIGN: Controlled observation.SETTING: Department of Medical Imaging, General Hospital of Jinan Military Area Command of Chinese PLA.PARTICIPANTS: Twenty-two patients (31 vertebral bodies) undergoing kyphoplasty with single balloon in Department of Medical Imaging, General Hospital of Ji'nan Military Area Command of Chinese PLA from May 2004 to May 2005 were selected, including 5 males and 17 females aged 68-85 years. Patients with painful compression fractures caused by osteoporosis were enrolled, and confirmed by CT and MRI with complete vertebral posterior wall but no spine deformity. The informed consent was obtained from all subjects, and the experiment and treatment were approved by Ethics Committee. METHODS: The especial instrument for kyphoplasty including puncturing device and balloon were provided by Shandong Guanlong Medical Utensils Co., Ltd. [LDAI (T) 2004 No. 2150017]; bone cement (Polymethymethacrylate) was made in China [MAIT 2005(T) No. 3650267]. Under X-ray fluoroscopy monitoring, single inflatable balloon was inserted into fractured vertebral body by puncturing needle and inflated via bipedicular approach to restore vertebral height. MAIN OUTCOME MEASURES: ①Bone cement biocompatibility during and after surgery; ②pain relief within 72 hours after surgery, restoration of vertebral height and correction of kyphotic deformity.RESULTS: ①Bone cement biocompatibility: Little cement leakage was observed at one intervertebral space of one patient by X-ray film, but no clinical symptoms, inflammatory reaction or rejection were found. ②Obvious pain relief was found in 22 cases with within 72 hours after kyphoplasty. ③The height loss of the anterior and middle vertebral body reduced from (14.70±4.21) mm and (10.62±4.11) mm preoperatively to (10.38±4.23) mm and (6.45±4.04) mm postoperatively after single balloon inflation and cement filling. Cobb angle was corrected averagely from (21.15±6.33)° preoperatively to (11.64±4.33)° postoperatively. CONCLUSION:Biocompatibility of bone cement is good, and no specific adverse effects are found in despite of cement leakage. Bipedicular kyphoplasty with single balloon for painful osteoporotic vertebral compression fractures effectively restores vertebral heights and relieves pain.