Postoperative decrease of regional volumetric bone mineral density measured by quantitative computed tomography after...

Area of Science:

• Orthopedic Surgery
• Radiology
• Bone Metabolism

Background:

• Limited research exists on postoperative bone mineral density (BMD) changes after lumbar fusion using quantitative computed tomography (QCT).
• Factors influencing postoperative BMD changes after lumbar fusion remain unclear.

Purpose of the Study:

• To assess the impact of posterior lumbar fusion on regional volumetric bone mineral density (vBMD) in adjacent vertebrae.
• To identify preoperative and operative factors that modify postoperative BMD changes.

Main Methods:

• Retrospective review of patients undergoing posterior lumbar fusion with pre- and postoperative CT scans.
• Analysis of vBMD changes in vertebrae adjacent to the instrumented levels (UIV+1, UIV+2, LIV+1).
• Inclusion of epidural steroid injection (ESI) history and interbody fusion as potential contributing factors.

Main Results:

• Posterior lumbar fusion led to a significant decrease in regional vBMD at adjacent levels (e.g., -10.5% at UIV+1).
• Interbody fusion and non-Caucasian race were independently associated with greater postoperative vBMD decline.
• Preoperative epidural steroid injections (ESIs) were associated with less pronounced postoperative vBMD decline.

Conclusions:

• Posterior lumbar fusion negatively impacts regional vBMD in adjacent vertebrae.
• Interbody fusion is an independent risk factor for vBMD decline post-surgery.
• Preoperative ESIs may offer a protective effect against postoperative vBMD reduction, possibly due to baseline vBMD changes.