[ Ⅲ ].

To investigate the clinical efficacy of long-segment pedicle screw reduction and internal fixation combined with kyphoplasty in the treatment of stage Ⅲ reducible Kummell disease. The clinical data of 32 patients with stage Ⅲ reducible Kummell disease treated at the Department of Orthopedics, Sir Run Run Shaw Hospital, Zhejiang University College of Medicine from January 2012 to March 2017 were analyzed retrospectively.There were 7 males and 25 females,aged (71.8±6.7)years(range:61 to 86 years).The injured segment was T in 1 patient,T in 8 patients,T in 13 patients,L in 7 patients,L in 2 patients and L in 1 patient.Preoperative American spinal injury association(ASIA) classification of patients all showed grade D.Bone mineral density (BMD),spinal X-ray,CT and MRI were examined before operation.All patients were treated with postural reduction, long-segment pedicle screw reduction and internal fixation combined with kyphoplasty.The operation time,intraoperative blood loss,length of stay and postoperative complications were recorded.The visual analogue scale (VAS) and Oswestry dysfunction index (ODI) as well as the BMD of hip were collected before and after operation.The Cobb angle of involved segment kyphosis and the height of anterior edge of diseased vertebrae were measured before operation,3 days and 12 months after operation.CT-related parameters were measured before and 3 days after operation,including sagittal anterior and posterior diameter of spinal canal,cross-sectional anterior and posterior diameter of spinal canal and cross-sectional spinal canal area.Paired sample test and repeated measures were used to compare the data before and after operation. All patients received the operation successfully.The operation time was (131.3±16.9) minutes (range:95 to 180 minutes),the blood loss was (82.5±27.1) ml (range:50 to 150 ml),and the length of stay was (8.3±2.4) days (range:5 to 14 days).All patients were followed up for more than 12 months.The VAS decreased gradually at 3 days,3 months,6 months and 12 months after operation,and the differences were statistically significant compared with the VAS before surgery (all <0.01).ODI at 3,6 and 12 months after surgery was significantly improved compared with that before surgery(All <0.01).The CT-related parameters at 3 days after operation were significantly higher than those before operation (All <0.05).At 12 months after surgery,the Cobb angle decreased from (35.2±7.6) ° preoperatively to (4.3±1.7) ° (=22.630,<0.01),the height of anterior edge of diseased vertebrae increased from (4.3±1.0) mm preoperatively to (16.9±2.5) mm(=-25.845,<0.01),the bone mineral density of hip increased from -(2.2±0.6) preoperatively to -(2.8±0.6)(=-0.040,<0.01).Up to the last follow-up,2 patients had distal pedicle screw loosening, 1 patient had proximal junctional kyphosis,and there was no new vertebral fracture. Based on postural reduction,long-segment pedicle screw reduction and internal fixation combined with kyphoplasty is a safe and effective treatment method for stage Ⅲ reducible Kummell disease,which can reconstruct the stability of the diseased vertebrae.Postoperative standard anti-osteoporosis treatment is the basis to ensure the efficacy.