Does Balloon Kyphoplasty Deliver More Cement Safely into Osteoporotic Vertebrae with Compression Fractures Compared with Vertebroplasty? A Study in Vertebral Analogues

[Translated article] Relation between the volume of injected cement and the vertebral volume in the clinical outcome and in the appearance of leakage after a percutaneous vertebroplasty

OBJECTIVES

To assess the connection between the volume of injected cement and the vertebral volume measured through a volumetric analysis with a computed tomography (CT scan) in relation to the clinical result and the appearance of a leakage in patients who underwent a percutaneous vertebroplasty after an osteoporotic fracture.

MATERIALS AND METHODS

A prospective study of 27 patients (18 female-9 male) with an average age of 69 years old (50-81), and with a one-year follow-up. The study group presented 41 vertebrae with osteoporotic fractures that were treated with a percutaneous vertebroplasty with a bilateral transpedicular approach. The volume of injected cement was registered in each procedure and it was assessed together with the spinal volume measured through a volumetric analysis with CT scans. The percentage of the spinal filler was calculated. The appearance of cement leakage was proved by means of a simple radiography and a postoperative CT scan in all the cases. The leaks were classified according to the location in relation to the vertebral body (posterior, lateral, anterior and in the disc), and the significance (minor: smaller than the largest diameter of the pedicle; moderate: larger than the pedicle but smaller than the height of the vertebra; major: larger than the height of the vertebra).

RESULTS

The average vertebra volume was 26.1cm3, the average volume of the injected cement was 2.0cm3 and the percentage of the average filler was 9%. A total of 15 leaks in 41 vertebrae appeared (37%). The leaks were posterior in 2 vertebrae, vascular in 8 and into the disc in 5 vertebrae. They were deemed as minor in 12 cases, moderate in 1 and major in 2 cases. The preoperative assessment of the pain was as it follows: VAS (8) and Oswestry (67%). The cessation of pain was immediate after a year with the following postoperative results: VAS (1.7) and Oswestry (19%). The only complication was the temporary neuritis with a spontaneous resolution.

CONCLUSIONS

The injection of small amounts of cement, lower than the ones referred to by literary sources, obtains clinical results similar to the ones obtained by injecting higher amounts and it reduces the number of cement leaks and further complications.

[Effect of percutaneous kyphoplasty with different phases bone cement for treatment of osteoporotic vertebral compression fractures]

Objective

To compare the effect of percutaneous kyphoplasty (PKP) with different phases bone cement for treatment of osteoporotic vertebral compression fracture (OVCF).

Methods

The clinical data of 219 OVCF patients who treated with PKP and met the selection criteria between June 2016 and May 2018 were retrospectively analyzed. According to the different time of intraoperative injection of bone cement, they were divided into observation group [116 cases, intraoperative injection of polymethyl methacrylate (PMMA) bone cement in low-viscosity wet-sand phase)] and control group (103 cases, intraoperative injection of PMMA bone cement in low-viscosity wire-drawing phase). There was no significance in general date of gender, age, disease duration, body mass index, bone mineral density T value, fracture vertebral body, preoperative fracture severity of the responsible vertebral body, anterior height ratio of the responsible vertebral body, preoperative pain visual analogue scale (VAS) score, and Oswestry disability index (ODI) between the two groups ( P>0.05). The VAS score and ODI score were used to evaluate the improvement of patients' symptoms at immediate, 2 days, 3 months after operation and at last follow-up. At 1 day, 3 months after operation, and at last follow-up, X-ray film and CT of spine were reexamined to observe the distribution of bone cement in the vertebral body, bone cement leakage, and other complications. During the follow-up, the refracture rate of the responsible vertebral body and the fracture rate of the adjacent vertebral body were recorded.

Results

The injection amount of bone cement in the observation group and control group were (4.53±0.45) mL and (4.49±0.57) mL, respectively, showing no significant difference between the two groups ( t=1.018, P=0.310). Patients in both groups were followed up 6-18 months (mean, 13.3 months). There were 95 cases (81.9%) and 72 cases (69.9%) of the bone cement distribution range more than 49% of the cross-sectional area of the vertebral body in the observation group and the control group, respectively, showing significant difference in the incidence between the two groups ( χ ²=4.334, P=0.037). The VAS score and ODI score of the postoperative time points were significantly improved compared with those before operation ( P<0.05), and there were significant differences among the postoperative time points ( P<0.05). The VAS score and ODI score of the observation group were significantly better than those of the control group ( P<0.05) at immediate, 2 days, and 3 months after operation, and there was no significant difference between the two groups at last follow-up ( P>0.05). At 1 day after operation, the cement leakage occurred in 18 cases of the observation group (8 cases of venous leakage, 6 cases of paravertebral leakage, 4 cases of intradiscal leakage) and in 22 cases of the control group (9 cases of venous leakage, 8 cases of paravertebral leakage, 5 cases of intradiscal leakage). There was no significant difference between the two groups ( P>0.05). During the follow-up, 5 cases (4.3%) in the observation group, 12 cases (11.7%) in the control group had responsible vertebral refracture, and 6 cases (5.2%) in the observation group and 14 cases (13.6%) in the control group had adjacent vertebral fracture, the differences were significant ( χ ²=4.105, P=0.043; χ ²=4.661, P=0.031).

Conclusion

Bone cement injection with wet-sand phase in PKP is beneficial for the bone cement evenly distributed, strengthening the responsible vertebral, relieving the short-term pain after operation, decreasing the rate of responsible vertebral refracture and adjacent vertebral fracture without increasing the incidence of relevant complications and can enhance the effectiveness.

Risk factors of recompression of cemented vertebrae after kyphoplasty for osteoporotic vertebral compression fractures

PURPOSE

To evaluate the risk factors correlated with loss of cemented vertebral body height after kyphoplasty in patients with osteoporotic vertebral compression fractures.

METHODS

Thirty-four consecutive patients with single-level osteoporotic vertebral compression fractures who underwent kyphoplasty in the Affiliated Hospital of Jiangsu University between January 2012 and August 2014 were retrospectively analysed. Eight independent variables (age, gender, body mass index, pre-operative T-score in bone mineral density, the volume of polymethylmethacrylate injected, pre-operatively vertebral body height, the restoration of body height and the distance between polymethylmethacrylate and endplate) were assessed. The recompression of body height was the dependent variable. Multivariate linear regression analyses were used to determine the factors associated with recompression of body height.

RESULTS

Multiple linear regression analyses indicated that the recompression of cemented vertebral body height was correlated with the distance between polymethylmethacrylate and endplate (P = 0.008, b' = 0.489). The final multiple linear regression model, which included only the distance between polymethylmethacrylate and endplate, resulted in a formula that accounted for 41.02 % of the recompression of body height.

CONCLUSIONS

The distance between polymethylmethacrylate and endplate is an important risk factor of recompression of cemented vertebrae after kyphoplasty for patients with osteoporotic vertebral compression fractures.

Pulmonary Artery Cement Embolism after a Vertebroplasty

Background Context. Vertebroplasty is a minimally invasive procedure most commonly used for the treatment of vertebral compression fractures. Although it is relatively safe, complications have been reported over time. Among those complications, massive cement pulmonary embolism is considered a rare complication. Here we report a case of massive diffuse cement pulmonary embolism following percutaneous vertebroplasty for a vertebral compression fracture. Study Design.

CASE REPORT

Methods. This is a 70-year-old female who underwent vertebroplasty for T11 and T12 vertebral compression fracture. Results. CT-scan revealed an incidental finding of cement embolism in the pulmonary trunk and both pulmonary arteries. Since the patient was asymptomatic, she was monitored closely and she did not need any intervention. Conclusion. Vertebroplasty is a minimally invasive procedure used for treatment of vertebral compression fracture. Despite the low rate of complications, a pulmonary cement embolism can occur. The consequences of cement embolism range widely from being asymptomatic to embolism that can cause paralysis, radiculopathy, or a fatal pulmonary embolism.