Objective:To investigate the short-term clinical outcomes of posterior percutaneous pedicle screw fixation combined with percutaneous vertebroplasty (PVP) for treating Kümmell's disease with intravertebral instability.Methods:A retrospective case series study was made on 18 patients with Kümmell's disease with intravertebral instability treated at Lishui Hospital of Zhejiang University from January 2012 to February 2016. There were 4 males and 14 females, aged 65-86 years [(76.0±5.5)years]. Segment of injury was T 7 in 1 patient, T 10 in 2, T 11 in 3, T 12 in 4, L 1 in 6, and L 2 in 2. All patients underwent posterior percutaneous pedicle screw fixation combined with PVP. The operation time, intraoperative blood loss, amount of cement injected into the vertebra, and length of postoperative hospital stay were recorded. The visual analogue scale (VAS), Oswestry disability index (ODI), Cobb angle, and wedge angle of the operative segment were recorded and compared preoperatively, postoperatively, and at the latest follow-up. Meanwhile, the complications were recorded. Results:All patients were followed up for 12-28 months [(17.7±4.4)months]. The operation time was 110-175 minutes [(137.9±21.9)minutes] and the blood loss was 50-165 ml [(110.7±35.6)ml]. The amount of cement injected into the vertebra was 2.5-6.0 ml [(4.7±0.9)ml]. The length of hospital stay was 7-14 days [(9.4±2.3)days]. The VAS was (7.8±1.2) points preoperatively, (3.3±0.7) points at 1 week postoperatively and (2.4±0.7)points at the latest follow-up. The ODI was (67.3±7.3)% preoperatively, (30.5±7.5)% at 1 week postoperatively and (21.8±8.3)% at the latest follow-up. The Cobb angle was (26.2±9.5)° preoperatively, (12.6±7.2)° at 1 week postoperatively and (16.7±6.2)°at the latest follow-up. The wedge angle was (21.1±6.1)° preoperatively, (8.4±4.6)° at 1 week postoperatively, and (13.2±4.1)° at the latest follow-up. The above clinical and radiological parameters were significantly improved after operation ( P<0.05), and showed no significant differences at the latest follow-up when compared to that at 1 week postoperatively ( P>0.05). Five patients showed slight screw loosening, but there was no obvious dislocation of internal fixation. One case developed distal vertebral compression fracture at 6 months postoperatively and cured after a second PVP. Conclusion:For Kümmell's disease with intravertebral instability, posterior percutaneous pedicle screw fixation combined with PVP can effectively restore and maintain the spinal sequence, rapidly relieve the pain and improve clinical function. However, the long-term efficacy needs further study.