We undertook a retrospective study investigating the accuracy and safety of percutaneous pedicle screws placed under fluoroscopic guidance in the lumbosacral junction and lumbar spine. The CT scans of patients were chosen from two centres: European patients from University Medical Center Hamburg-Eppendorf, Germany, and Asian patients from the University of Malaya, Malaysia. Screw perforations were classified into grades 0, 1, 2 and 3. A total of 880 percutaneous pedicle screws from 203 patients were analysed: 614 screws from 144 European patients and 266 screws from 59 Asian patients. The mean age of the patients was 58.8 years (16 to 91) and there were 103 men and 100 women. The total rate of perforation was 9.9% (87 screws) with 7.4% grade 1, 2.0% grade 2 and 0.5% grade 3 perforations. The rate of perforation in Europeans was 10.4% and in Asians was 8.6%, with no significant difference between the two (p = 0.42). The rate of perforation was the highest in S1 (19.4%) followed by L5 (14.9%). The accuracy and safety of percutaneous pedicle screw placement are comparable to those cited in the literature for the open method of pedicle screw placement. Greater caution must be taken during the insertion of L5 and S1 percutaneous pedicle screws owing to their more angulated pedicles, the anatomical variations in their vertebral bodies and the morphology of the spinal canal at this location.

Cite this article: Bone Joint J 2015; 97-B:1111–17.

This study prospectively compared the efficacy of kyphoplasty using a Jack vertebral dilator and balloon kyphoplasty to treat osteoporotic compression fractures between T10 and L5. Between 2004 and 2009, two groups of 55 patients each underwent vertebral dilator kyphoplasty and balloon kyphoplasty, respectively. Pain, function, the Cobb angle, and the anterior and middle height of the vertebral body were assessed before and after operation. Leakage of bone cement was recorded. The post-operative change in the Cobb angle was significantly greater in the dilator kyphoplasty group than in the balloon kyphoplasty group (−9.51° (sd 2.56) vs −7.78° (sd 1.19), p < 0.001)). Leakage of cement was less in the dilator kyphoplasty group. No other significant differences were found in the two groups after operation, and both procedures gave equally satisfactory results in terms of all other variables assessed. No serious complications occurred in either group.

These findings suggest that vertebral dilator kyphoplasty can facilitate better correction of kyphotic deformity and may ultimately be a safer procedure in reducing leakage of bone cement.