[Clinical effects of lumbar brace on bone mineral density and screw stability after lumbar spinal surgery]

To analyze the effect of wearing a lumbar corset after internal fixation surgery for lumbar degenerative diseases on patients' vertebral bone mineral density (BMD) and screw stability.

A total of 123 patients with lumbar degenerative diseases who underwent posterior lumbar decompression, bone grafting, fusion, and internal fixation from January 1, 2021 to December 31, 2023 were prospectively enrolled. Using a random number table method, patients were divided into two groups according to the postoperative lumbar corset wearing time:70 cases in the 1-month wearing group 70 cases, including 20 males and 50 females, aged (63.4±7.9) years;and 50 cases in the 3-month wearing group, including 18 males and 35 females, aged (64.3±7.5) years. To deeply analyze the impact of osteoporosis status on outcomes, all patients were further divided into an osteoporosis subgroup (54 cases) and a non-osteoporosis subgroup (69 cases) based on preoperative bone mineral density results following the initial randomization. All patients underwent plain lumbar CT scans preoperatively and at 1, 3, and 6 months postoperatively. Bone's FRAX V1.0 software was used to quantitatively measure vertebral bone mineral density and assess screw stability, aiming to compare the temporal changes under different wearing durations and different bone mineral density states. Preoperatively and at the final follow-up, the visual analogue scale (VAS) was used for pain scoring, and the Oswestry disability index (ODI) was used for dysfunction evaluation.

All patients were followed up for 6 months. Regardless of whether they were osteoporotic or non-osteoporotic, the vertebral BMD of patients in the 1-month group was significantly higher than that of patients in the 3-month group at the 3rd and 6th months postoperatively (P<0.05);the BMD loss in the 3-month group was greater than that in the 1-month group at 3 and 6 months postoperatively (P<0.05). In addition, although the imaging-observed screw loosening rates were relatively high in both the 1-month and 3-month groups, no clinical symptoms occurred. Whether in osteoporotic or non-osteoporotic patients, there was no statistically significant difference in screw loosening rates between the 1-month and 3-month groups (P>0.05). At the final follow-up, the VAS for low back pain in the 1-month group decreased from (7.05±1.08) preoperatively to (2.90±1.02), while that in the 3-month group decreased from (7.19±0.91) preoperatively to (2.83±0.95), with no statistically significant difference between the two groups at the final follow-up (P=0.699). At the final follow-up, the ODI in the 1-month group decreased from (39.69±15.12) preoperatively to (13.08±8.06), while that in the 3-month group decreased from (37.78±14.62) preoperatively to (12.79±8.02), with no statistically significant difference between the two groups at the final follow-up(P=0.520).

Patients with lumbar degenerative diseases lose more and faster vertebral BMD when wearing a lumbar corset for 3 months postoperatively compared to wearing it for only 1 month. However, different corset wearing durations and different osteoporosis statuses have no significant impact on postoperative screw stability.