ABSTRACT
Objective:To compare the clinical efficacy of pedicle subtraction osteotomy (PSO) versus vertebroplasty (VP) combined with long segment fixation for nonunion of osteoporotic vertebral fractures with kyphosis.Methods:A retrospective cohort study was conducted to analyze the clinical data of 72 patients with nonunion of osteoporotic vertebral fractures with kyphosis admitted to Jiangnan Hospital affiliated to Zhejiang University of Traditional Chinese Medicine from January 2010 to December 2017. There were 16 males and 56 females, aged 55-84 years [(68.2±5.2)years]. Level of injury was located at T 11 in 3 patients, at T 12 in 19, at L 1 in 31, and at L 2 in 19. According to the American Spinal Injury Association (ASIA) classification, 31 patients were scaled as grade D and 41 grade E. Overall, 51 patients were treated with PSO combined with long segment fixation (PSO group) and 21 patients treated with VP combined with long segment fixation (VP group). The operation time and bleeding volume were compared between the two groups. Before operation, at postoperative 2 weeks and at the last follow-up, the kyphotic Cobb angle, sagittal vertical axis (SVA), thoracic kyphosis (TK) and lumbar kyphosis (LL) were used to evaluate the osteotomy effect, and the visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate the degree of pain and lumbar function recovery. The improvement of ASIA grade was observed at the last follow-up. The complications were observed as well. Results:All patients were followed up for 24-46 months [(33.2±5.9)months].The operation time and bleeding volume were more in PSO group than in VP group (all P<0.01). Before operation, the kyphotic Cobb angle, SVA, TK and LL were not significantly different between the two groups (all P>0.05). At postoperative 2 weeks, TK was not significantly different between the two groups ( P>0.05), while PSO group showed significantly decrease of kyphotic Cobb angle and SVA and increase of LL when compared with VP group ( P<0.05 or 0.01). At the last follow-up, the kyphotic Cobb angle, SVA and TK in PSO group were (8.5±1.1)°, (2.6±0.5)cm and (28.8±6.2)°, respectively, significant lower than those in VP group [(14.2±1.5)°, (4.4±0.9)cm and (32.6±5.9)°] (all P<0.05); while the LL was significantly larger in PSO group [(43.1±3.9)°] than in VP group [(36.9±5.3)°] ( P<0.01). Before operation, the VAS and ODI were not significantly different between the two groups (all P>0.05). At postoperative 2 weeks, the VAS and ODI in the two groups were also not significantly different (all P>0.05), but both were greatly decreased from the preoperative level (all P<0.05). At the last follow-up, the VAS and ODI in PSO group were (1.4±0.5)points and 22.5±2.5, significant higher than (1.8±0.6)points and 25.5±5.1 in VP group (all P<0.01). At the last follow-up, the ASIA classification was grade E in all patients. There were 1 patient suffering from dural matter tear and 1 from proximal junctional kyphosis in PSO group. Whereas 3 patients had bone cement leaking and 1 pedicle screw loosening in PVP group. The complication rate was 3.9% (2/51) in PSO group, significant lower than 19.0%(4/21) in VP group ( P<0.05). Conclusion:Compared with VP group in the treatment of osteoporotic vertebral fractures with kyphosis, PSO combined with long segment fixation is much effective in improving kyphosis angle and spinal axial imbalance correction, maintaining vertebral height and spinal axial stability in middle- to long-term, improving pain and dysfunction and minimizing complications, regardless of more operation time and bleeding volume.