The Clinical Evaluation of Calcium Phosphate Cement Compared with Polymethylmethacrylate for Kyphoplasty

ABSTRACT

OBJECTIVE: We investigated the clinical outcome of kyphoplasty using calcium phosphate (CaP) for vertebral augmentation compared with polymethylmethacrylate (PMMA). We conducted a retrospective study to determine whether patients with osteoporotic vertebral fracture who underwent CaP kyphoplasty had improved outcome in the correction of vertebral body and relief of pain compared with those who underwent PMMA treatment. METHODS: From January 2005 to December 2006, 117 consecutive patients with osteoporotic compression fracture were treated at our institute. Among them, 23 patients have treated to kyphoplasty using PMMA or CaP. We reviewed the clinical data and imaging studies retrospectively as sources for analysis. RESULTS: The 23 patients included in the study. A mean ages of CaP and PMMA group were 70+/-9.5 and 67+/-9.5 years respectively. Preoperative compression ratios (CR) were 0.71+/-0.12 and 0.74+/-0.15 on both groups. Postoperative CR, however, showed the difference between two groups. The differences of preoperative and postoperative Cobb`s angle were 10.04 and 2.18 on CaP and PMMA group respectively and the mean injected volume of cement were 3.85+/-1.73 and 4.4+/-1.23 ml. CONCLUSION: The amount of injected volume of bone cement in kyphoplasty has no difference on both groups. But, follow-up compression ratio and Cobb`s angle are larger in CaP group than PMMA group. However, pain and functional recovery is not different on both group. As a result, CaP can not sufficiently support the strength of vertebral body, but be used to control the acute pain.