The Evaluation of the Ilium and Biocompatible Orthopaedic Polymer(BOP) as Graft Material in Cervical Spine Surgery

Shin, Won Han; Park, Jin Kyu; Kim, Bum Tae; Choi, Soon Kwan; Byun, Bark Jang

Abstract

Traditional anterior interbody fusion with autograft has limitations such as graft collapse, graft extrusion, pseudoarthrosis, and donor site morbidity. A short hospital stay and reduced donor site complications can be achieved by using synthetic graft materials such as Biocompatible Orthopaedic Polymer(BOP). A retrospective study to evaluate bone graft was carried out in a series of 111 patients in whom interbody fusions were performed for cervical spondylosis and cervical spine injury using anterior(modified Trans-Unco-Discal) approach with autogenous ilium or BOP between January 1988 and December 1994 at our hospital. The radiological assessments were made between postoperative and follow-up x-ray findings, and the postoperative clinical results and complications were statistically analyzed. The major results were as follows: 1) Clinical results of spondylotic patients were graded excellent in 57%, good in 32% and fair in 11% in ilium group, and excellent 65%, good 25%, fair 5% and poor 5% in BOP group. Clinical results patients with cervical injury were graded excellent in 25%, good in 25%, fair in 25% and poor in 25% in ilium group, and excellent 29%, good 21%, fair 29% and poor 21% in BOP group. As to graft materials, there were no statistically significant difference in clinical results(p=0.76, p=0.75). 2) Mean height of graft bone were 13.0mm in ilium group and 10.0mm in BOP group at postoperative x-ray findings, and 11.6mm in ilium group and 6.1mm in BOP group at follow-up x-ray findings. Incidence where the height of graft bone at follow-up x-ray findings was less than 80% of immediately postoperative height were 7% in ilium group and 58% in BOP group, and there was a statistically significant difference(p<0.05). BOP sank into the adjacent end plate as compared to ilium. 3) Mean duration of period required for fusion was about 40 days in ilium group and 132 days in BOP group with a statistically significant difference (p<0.01). 4) The rate of complications related to bone graft was 16% in ilium group and 30% in BOP group. Incidence of complications was higher in BOP than ilium group, but there was no statistically significant difference(p=0.28). According to the above results, clinical results were not significantly different between both graft materials, but ilium was superior to BOP as a good spacer with maintenance of height of graft bone and good bony fusion.