A novel bone cement screw system combined with vertebroplasty for the treatment of Kummell disease with bone deficiency at the vertebral anterior border: A minimum 3-year follow-up study.

OBJECTIVES:When vertebroplasty is used to treat Kummell disease with bone deficiency at the vertebral anterior border, bone cement displacement often occurs intraoperatively or postoperatively. We designed and used a new bone cement screw system to avoid this serious complication. The purpose of this study was to evaluate the safety and effectiveness of this novel operation method through more than 3 years of follow-up. PATIENTS AND METHODS:From January 2014 to August 2016, 27 patients suffering from single-segment Kummell disease with bone deficiency at the vertebral anterior border were treated by vertebroplasty combined with a novel bone cement screw. Bone cement was released into the diseased vertebrae through the screw to fully fill the intravertebral vacuum cleft. Screw fixation of bone cement can avoid intraoperatively or postoperatively displacement. All patients received surgery involving a unilateral technique, and only one screw was implanted in each patient. The clinical efficacy was evaluated using Odom's criteria and statistical analysis of the vertebral body index (VBI), vertebral body angle (VBA), bisegmental Cobb angle (BCA), visual analogue scale (VAS), Oswestry disability index (ODI), and the results of the MOS 36-item short form health survey (SF-36). RESULTS:The operation was completed successfully in 27 cases. The average operation time was 49.63 ± 10.82 min, and the average volume of cement injected was 4.70 ± 0.87 mL. The patients' preoperative VBI, VBA, BCA, VAS and ODI scores were 43.11 ± 5.94, 21.04 ± 2.55, 45.00 ± 6.26, 7.59 ± 0.84, and 79.85 ± 7.58, respectively. The postoperative measurements were 78.70 ± 2.55, 12.70 ± 2.11, 26.11 ± 4.73, 3.22 ± 0.93 and 50.04 ± 9.28, respectively. At the last follow-up, the measurements were 78.04 ± 2.30, 13.15 ± 2.38, 27.07 ± 4.87, 2.04 ± 0.65, and 22.85 ± 5.06, respectively. There was a significant difference between the preoperative and postoperative data, as well as the preoperative and the last follow-up data (P < 0.05). Comparing the results of SF-36 before operation and at the last follow-up revealed significant differences in physical function, role-physical, body pain, vitality, and social function (P < 0.05). However, there were no significant differences in general health, emotional function and mental health. Finally, 26 patients (96.3 %) had good to excellent clinical outcomes according to Odom's criteria. CONCLUSIONS:This 3-year follow-up study shows that the novel bone cement screw system combined with vertebroplasty has a good short and medium-term therapeutic effect in patients with Kummell disease and bone deficiency at the vertebral anterior border, while its long-term efficacy is subject to further studies.