Effect of carbonated hydroxyapatite cement for filling vertebral body on the vertebral heights and pain in patients with osteoporotic vertebral compression fractures

Keya MAO; Baowei LIU; Yan WANG; Sheng TAO; Jifang WANG; Zhengsheng LIU; Songhua XIAO; Yonggang ZHANG

ABSTRACT

BACKGROUND:

Carbonated hydroxyapatite cement (CHC) s a new kind of biomaterial for bone defect, which is made of powder and fluid, and can be mixed to be pasty to repair various bone defects.

OBJECTIVE:

To observe the improvement of vertebrae height and pain in patients with osteoporosis vertebral compression fracture (VCF) after vertebroplasty by using a new kind of bone graft biomaterial, taking CHC as the filling material to reinforce the vertebral body.

DESIGN:

A contrast observation trial taking patients as subjects.

SETTING:

Department of Orthopaedics, General Hospital of Chinese PLA.

PARTICIPANTS:

Totally 34 patients with thoracic or lumbar osteoporosis VCF who received the treatment in the Department of Orthopaedics, General Hospital of Chinese PLA between October 2000 and August 2003. Inclusive criteria ①Definite diagnosis by CT; ② Informed consents were obtained from the patients. Exclusive criteria The patients with osteoporosis vertebral compression fractures who suffered vertebral posterior wall fracture. There were 6 males and 28 females, and they were aged (72±13)years; Among the patients, 27 were diagnosed as postmenopausal osteoporosis, 1 as cortical hormone-induced osteoporosis and 6 male patients weresenile osteoporosis.

METHODS:

①All the patients were randomly divided into two groups Experimental group (n =23) and control group (n=11). All the patients were performed percutaneous operation with local anesthenia. All cases were performed percutaneous operation under local anesthesia. Under the C-arm monitored, one side pedicle puncture was performed to enter the anterior column of the involved VCF. Patients of the experimental group were filled with CHC. Patients of control group were filled with polymethyl Methacrylate (PMMA) with the same way. ② Referred to McGill-Melzack scoring. Among the scale 0-100 mm (0 was no pain, 100 was acute pain), the value indicated the painful intensity and mental assault degree. ＜ 30 scores indicated good, 30-40 basically satisfied and ≥ 50 poor .③ Referred to the method from Lee et al, the preoperative height (A1) and postoperative height (A2) of compression fracture position of VCF were measured according to the lateral X-ray film. At the same time, the upper vertebral height (A3) and the inferior vertebral height (A4) were measured at the same position. The original height (A) of the involved vertebra was calculated as (A)= (A3+A4)/2,and the preoperative vertebral compression rate =(A-A1 )/A, the postoperative vertebral compression rate =(A-A2)/A, the restoring rate = (the preoperative vertebral compression rate-the postoperative vertebral compression rate)/the preoperative vertebral compression rate. ④ The wounds of the patients were observed after operation. The levels of blood routine, serum calcium and serum phosphorus were detected before, one day and one week after operation. MAIN OUTCOME

MEASURES:

① Preoperative and postoperative VAS scoring. ② The vertebral compression rate and restoring rate. ③ Wounds were observed after operation. The blood routine, the serum calcium and serum phosphorus were detected before, one day and one week after operation.

RESULTS:

Totally 34 patients were involved in the result analysis. ①The preoperative visual analogue scale (VAS) score of experimental group were (91.5±21.7) points, and the postoperative ones were (44.5±27.2) points. The difference of VAS score reduced gradually along with the postoperative time. There was no difference of VAS score between experimental group and the control group 4 weeks after operation. ② The biocompatibility of CHC in the vertebral body was fine. The vertebral compression rate of experimental group was recovered from (43.1±21.4)％ preoperatively to (27.3± 18.5)％ postoperatively. The rate of restored heights was (27.3±18.5)％. ③ All patients obtained Ⅰ stage wound healing, and none of them had infection, inflammatory secretion and nervous symptom. There were no differences in blood routine test, serum calcium, serum phosphorus between patients in two groups. One case filled by PMMA and two cases filled by CHC presented leakage, and none had nervous symptom.

CONCLUSION:

As the filling materials for vertebropalsty, CHC can restore the vertebral heights and relieve pain safely and effectively, however, its efficacy to relieve pain is not significant as PMMA in the short term.