Therapeutic efficacy of injectable calcium phosphate cement in osteoporotic vertebral compression fractures: prospective nonrandomized controlled study at 6-month follow-up.

Background: Alternative biocompatible filler materials replacing polymethylmethacrylate (PMMA) cement have been introduced and clinically tested. Callos calcium phosphate cement (CPC) is one of them. A prospective nonrandomized controlled study was performed to assess the clinical and radiologic results after balloon kyphoplasty with Callos CPC in osteoporotic vertebral compression fractures.

Methods: Twenty-six patients were enrolled in this study. Clinical outcome was assessed using the Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI). The degree of vertebral height loss and changes in the kyphotic angle were measured using plain-film x-rays. Blood tests were carried in all cases out to observe the variation in postoperative serum calcium levels.

Results: The VAS and ODI scores decreased from 7.5 ± 1.1 to 2.2 ± 1.4 (P = .000) and from 31.7 ± 1.6 to 16.9 ± 1.7 (P = .000), respectively. Although vertebral height loss (M = 25.4% ± 17.4%) was reduced after the operation (M=22.1% ± 15.3%, P = .002), recurrent progression of height loss was observed during the follow-up (M = 32.7% ± 19.6%, P = .001). The kyphotic angle (M = 8.1° ± 4.8°) did not significantly change postoperatively (M = 8.7° ± 5.5°, P = .350), and the serum calcium level was within normal ranges. CPC leakage to the spinal canal was observed in 15 cases (48.4%), and none of them presented any related clinical symptoms except one patient, who had transient intercostal neuralgia.

Conclusions: Subsequent loss of augmentation properties during follow-up is a serious problem of kyphoplasty using injectable CPC in osteoporotic vertebral compression fractures. The clinical use of injectable CPC in kyphoplasty should be reconsidered.