INTRODUCTION

Case controlled study. The purpose of this study is to clarify the short-term clinical results of Balloon kyphoplasty combined with percutaneous pedicle screw (PPS) fixation (BKP+PPS) for painful and unstable osteoporotic vertebral body fracture (OVF) and compare it with percutaneous vertebroplasty with HA block combined with PPS fixation (HA+PPS).

METHODS

The clinical study proposal was approved by the medical ethical committee of our institution. From May 2013 to November 2019, out of 31 cases (4 males, 26 females, average age at surgery 75.5 years) who performed vertebroplasty and posterior fixation with PPS by the same operator for painful OVF, the subjects were 24 patients (3 males, 21 females, mean age at surgery 78.0 years) who could be followed up more than 2 years after surgery. The surgical procedure is percutaneous vertebroplasty for 1 vertebral body and posterior stabilization with PPS (without direct neural decompression procedure) for  unstable OVF with intra- or inter-vertebral instability. We divided these into 12 cases of HA+PPS (group H) and 12 cases of BKP+PPS (group B), and investigated the clinical results. We evaluated time from injury to surgery, pre- and post-operative visual analogue scale (VAS) of low back pain, wedging angle of fractured vertebra, duration of operation, intraoperative blood loss, number of instrumented vertebra, and length of stay at hospital.

RESULTS

Number of instrumented vertebra is 3.1 ± 0.8 in H and 2.8 ± 1.2 in B , there was no difference between the two groups. The average operation time was 95.3 ± 22.9 minutes in H, 72.6 ± 33.2 minutes in B (P = 0.016), and the average intraoperative blood loss was 99.2±42.5 g in H and 47.6±9.9 g in B (P = 0.001). The average hospital length was 17.8±9.0 days in H, 8.8±4.6 days in B (P = 0.003). The VAS immediately after surgery was significantly lower (P < 0.005) than that of before surgery in two groups. The VAS at 1 and 2 years after surgery was significantly decreased (P < 0.05) in two groups. The wedging angle of fractured vertebra was significantly lower (P < 0.005) than that of before surgery in two groups. The wedging angle of fractured vertebra immediately after surgery was 7.3 ± 5.8 degrees in H and 4.3 ± 3.6 degrees in B, but no difference was observed. The wedging angle of fractured vertebra 2 years after surgery was 12.3 ± 6.8 degrees in the H and 4.6 ± 3.6 degrees in the B, showing a significant correction loss in the H group (P = 0.002). In both groups, bone union was obtained in all cases 1 year after surgery. None of the patients were found to have any postoperative neurological complications.

DISCUSSION

BKP+PPS  for unstable OVF was suggested to be minimally invasive in the elderly patients. In addition, there is no correction loss of the fractured vertebral body 2 years after BKP+PPS, which is considered to be a useful surgical procedure. Further long-term follow-up and further verification are necessary, including the necessity of implant removal.