Effect of intervertebral bone graft area on the effect of single-level posterior lumbar decompression and bone graft fusion

Abstract

To study the effect of intervertebral grafting area on the effect of single segment lumbar posterior decompression and intervertebral bone grafting fusion. The clinical data of 52 patients who underwent single-segment lumbar posterior decompression pedicle internal fixation and bone grafting fusion from January 2020 to December 2022 were retrospective reviewed. The area of the intervertebral bone graft was measured one week postoperatively using Computed Tomography (CT), and based on the ratio of the bone graft area to the average area of the endplates, the patients were divided into three groups:17 cases in group A(the intervertebral bone graft area did not exceed the area of one pedicle) included 9 males and 8 females with an average age of (56.0±11.5) years old;15 cases in group B(the intervertebral bone graft area exceeded one pedicle but did not reach the opposite pedicle) included 10 males and 5 females with an average of (52.0±14.0) years old; 20 cases in group C (the intervertebral bone graft area exceeded the opposite pedicle) included 12 males and 8 females with an average of (49.5±12.8) years old. X-rays and CT scans were performed at 3, 6, 12 months, and the final follow-up postoperatively, the interbody fusion Brantigan scores, pain visual analogue scale (VAS), and Oswestry Disability Index (ODI) at each follow-up were recorded. The gender, age, and surgical segments showed no significant differences among three groups(P>0.05). There was also no significant difference in the preoperative VAS and ODI among three groups (P>0.05). All patients of three groups were followed up from 12 to 36 months. Compared with preoperative, VAS and ODI scores of three groups showed significant improvement at 1 week postoperatively and the final follow-up (P<0.05). Compared with preoperative measurements, the height of the intervertebral space was restored at 1 week postoperatively in three groups;at the final follow-up, the loss of height in the intervertebral space was less in groups B and C, and the height of the intervertebral space in group B and C was significantly higher than in group A(P<0.05). The modified Brantigan scores at 3 and 6 months postoperatively were significantly higher in group C than in groups A and B (P<0.05);at 12 months postoperatively, the scores in groups B and C were significantly higher than in group A(P<0.05);however, at the final follow-up, there was no significant difference in the modified Brantigan scores among three groups(P>0.05). The bone graft fusion rate in group C was significantly higher than in groups A and B at 3 months postoperatively(P<0.05);at 6 and 12 months postoperatively, the fusion rates in groups B and C were significantly higher than in group A(P<0.05);at the final follow-up, the fusion rate in group A was still lower than in groups B and C, but the difference among three groups was not significant(P>0.05). Single segment posterior lumbar decompression and interbody fusion surgery can significantly improve the clinical symptoms of patients with lumbar degenerative related diseases. However, as the proportion of bone grafting area increases, the early bone grafting fusion rate and fusion score of patients are significantly improved.