Purpose. To compare efficacy of balloon kyphoplasty in restoring vertebral height and correcting kyphosis in patients having vertebra plana with or without osteonecrosis. Methods. 12 women and 3 men (mean age, 76 years), who had a complete vertebra plana with or without osteonecrosis (n=8 vs n=7), underwent balloon kyphoplasty. No external manoeuvres were performed before or during balloon kyphoplasty, except for positioning the patients in a prone posture on the operating table. The anterior, middle, and posterior vertebral height and the kyphotic angle were measured pre-and post-operatively with a digital imaging system. The vertebral height was measured as a percentage of the adjacent normal vertebral height. Results. Respectively in vertebra plana patients with or without osteonecrosis, the mean corrections of (1) kyphosis were 10º and 4º (p=0.099), (2) anterior vertebral height were 33% and 5% (p<0.001), (3) middle vertebral height were 38% and 18% (p=0.004), and (4) posterior vertebral height were 19% and 2% (p=0.031).

Our study shows good correlation of mineralisation and mechanical property of the inferior tibial facies. Therefore, as the results provide information on the topographical distribution of bone quality, they could be useful for the development of new fixation methods for total ankle prosthesis.

Vertebroplasty and kyphoplasty are associated with a recurrent fracture rate of 2.4% to 23%, which is lower than the general natural history of untreated osteoporotic fractures. Some authors suggest the risk of refracture at adjacent vertebra will be reduced by prophylactic stabilization. We therefore compared the refracture rate after prophylactic balloon kyphoplasty in 60 patients randomized into groups with either monosegmental balloon kyphoplasty or adjacent prophylactic balloon kyphoplasty. The level (superior versus inferior) for prophylactic stabilization was chosen according to fracture type. We evaluated patients for 12 months using radiographs, visual analog scale scores, and SF-36 scores. We followed 23 of 30 patients in the monosegmental group and 27 of 30 patients in the prophylactic group. We observed no difference in the 1-year refracture rates between the two groups (five patients in the monosegmental group and seven in the prophylactic group). Leakage into the disc was the presumed cause of adjacent fractures in 50% of the patients. Disc leakage and refracture rate did not correlate as a result of the low patient number. Based on our data, we believe there is no indication for prophylactic stabilization of adjacent segments with balloon kyphoplasty.

We report a case of cement leakage into the posterior spinal canal due to inadvertent pedicle perforation during balloon kyphoplasty. The leakage was corrected immediately without any sequelae. Features seen on radiography and the minimally invasive procedure used for removal are described. The postoperative radiographs of 100 consecutive patients treated with balloon kyphoplasty were subsequently reviewed. Only one patient had a similar leakage but had no neurological complications.

In case of revision or minimal invasive spinal surgery, the amount of autograft possibly harvested from the lamina and the spinous processes is limited. Ekanayake and Shad (Acta Neurochir 152:651-653, 2010) suggest the application of bone shavings harvested via high speed burr additionally or instead, but so far no data regarding their osteogenic potential exist. Aim of the study was to compare the osteogenic potential of bone chips and high speed burr shavings, and to evaluate the applicability of bone shavings as an autograft for spinal fusion. Bone chips and shavings from 14 patients undergoing spinal decompression surgery were analyzed using in vitro tissue culture methods. Osteoblast emigration and proliferation, viability and mineralization were investigated and histological evaluation was performed. Bone chips from all patients showed successful osteoblast emigration after average 5.5 days. In contrast, only 57% of the corresponding bone shavings successfully demonstrated osteoblast emigration within an average time span of 14.8 days. Average osteoblast mobilisation was 1.25 9 10 6 cells per gram from bone chips and 1.73 9 10 5 cells per gram from the corresponding bone shavings. No difference was observed regarding cell viability, but population doubling times of bone chip cultures were significantly lower (50.5 vs. 121 h) and mineralization was observed in osteoblasts derived from bone chips only. Although some authors suggest the general applicability of laminectomy bone shavings as autografts for spinal fusion, autologous bone grafts obtained from laminectomy bone chips are superior in terms of cell delivery, cell proliferation and mineralization.