The effect of distribution of bone cement in the fracture lines on the outcome of percutaneous vertebroplasty

English Keywords:Percutaneous vertebroplasty  Bone cement diffusion  Osteoporosis vertebral compression fracture  Fracture line  Kyphosis

English Abstract:

  【Abstract】 Objectives: To evaluate the effect of distribution of bone cement in the fracture lines on the outcome of percutaneous vertebroplasty(PVP). Methods: 45 patients were analyzed retrospectively in this study, all cases were diagnosed as thoracolumbar osteoporosis vertebral compressional fracture(OVCF) and treated by PVP(T10-L2) from September 2009 to December 2011. There were 14 males and 31 females, with a mean age of 72.18 years(53-88ys), the average duration was 17.36d(2h-4m). The distritution of vertebral fracture lines was determined based on preoperative CT or MRI. According to the relationship between bone cement and fracture lines in postoperative X-ray or CT, patients were allocated to group A(n=30): bone cement diffusing into fracture line sufficiently, and group B(n=15): bone cement diffusing into fracture line insufficiently or absently. VAS, ODI and local kyphotic Cobb angle at preoperation, 3 days after the operation and the last follow-up as well as the complication were compared between two groups. Results: PVP were performed successfully in all patients without severe complication. The baseline characters except the BMD showed no significant difference between two groups. VAS and ODI scores after operation improved significantly compared with preoperative ones in both groups(P<0.05). Compared with preoperation, VAS and ODI at 3 days after surgery of group A was higher than those of group B(VAS: 5.03±1.33 vs 3.53±1.13, ODI: 26.17±2.10 vs 24±2.03, P<0.05), but there was no significant difference between two groups at the last follow-up(P＞0.05). The local kyphotic Cobb angle at 3 days after operation in two groups decreased significantly compared with preoperative ones(P<0.05). There was no significant difference between 3 days after operation and the last follow-up in group A(P>0.05). However, in group B, the local kyphotic cobb angle at the last follow-up was significantly higher than that at 3 days after surgery(P＜0.05). Loss of correction in group A was significantly lower than that in group B(1.08°±0.38° vs 3.58°±0.37°, P＜0.05). 8 cases in group A and 6 cases in group B presented asymptomatic bone cement leakagerespectively, with a total leakage rate of 31.1%. Conclusions: PVP is an effective therapy for thoracolumbar OVCF due to its pain relief and function recovery. Insufficient bone cement distribution in the fracture lines may affect the short-term clinical outcome, furthermore, it may be a risk factor to induce progressive kyphotic deformity.