Radiological Assessment of Postoperative Paraspinal Muscle Changes After Lumbar Interbody Fusion With or Without Minimally Invasive Techniques

Abstract

Study Design: Retrospective cohort study. Background: Percutaneous pedicle screws (PPS) have the advantage of being able to better preserve the paraspinal muscles when compared with a traditional open approach. However, the nature of changes in postoperative paraspinal muscle after damage by lumbar fusion surgery has remained largely unknown. It is clinically important to clarify and compare changes in paraspinal muscles after the various surgeries. Objective: (1) To determine postoperative changes of muscle density and cross-sectional area using computed tomography (CT), and (2) to compare paraspinal muscle changes after posterior lumbar interbody fusion (PLIF) with traditional open approaches and minimally invasive lateral lumbar interbody fusions (LLIF) with PPS. Methods: We included data from 39 consecutive female patients who underwent open PLIF and 23 consecutive patients who underwent single-staged treatment with LLIF followed by posterior PPS fixation at a single level (L4-5). All patients underwent preoperative, 6 months postoperative, and 1-year postoperative CT imaging. Measurements of the cross-sectional area (CSA) and muscle densities of paraspinal muscles were obtained using regions of interest defined by manual tracing. Results: We did not find any decrease of CSA in any paraspinal muscles. We did find a decrease of muscle density in the multifidus at 1 year after surgery in patients in the PILF group, but not in those in LLIF/PPS group. Conclusions: One year after surgery, a significant postoperative decrease of muscle density of the multifidi was observed only in patients who underwent open PLIF, but not in those who underwent LLIF/PPS.

Changes in Paraspinal Muscles after PLIF versus Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion (PE-TLIF) in Patients with Lumbar Spinal Stenosis: A One-Year Prospective Study

“…However, at 6 months after surgery, there was no signi cant difference in the FI rate or muscle density between the two groups. Although it is not clear how long it takes from paraspinal muscle injury until there is detectable FI, some studies have shown that 12 months after surgery is a reasonable time to evaluate postoperative FI [29,30]. He et al believe that there exists a mutual effect between paraspinal muscle FI and muscle atrophy [31], and we speculate that there will be a difference in the paraspinal muscle area between the two groups after long-term follow-up.…”

Changes in paraspinal muscles and facet joints after percutaneous endoscopic transforaminal lumbar interbody fusion for the treatment of lumbar spinal stenosis: A 3-year follow-up

“…In order to evaluate the changes of MF after PE-TLIF, we compared the FCSA and FI rate of MF at pre-operation, 12-month follow-up, 24-month follow-up, and at final follow-up. Some studies have shown that the decrease of muscle volume and the increase of fat deposition are the main characteristics of paraspinal muscle degeneration ( 23 , 24 ). Kang et al confirmed by MRI that the degree of paraspinal muscle degeneration can be reflected by the decrease of paraspinal muscle FCSA and FI ( 25 ).…”

Imaging of muscle and adipose tissue in the spine: A narrative review

“…In addition, an increase in fatty infiltration is reflected by a decrease in mean density (Hounsfield units (HU)) [ 15 ] (Table 1 summarizes the pathological manifestations and corresponding imaging features of the paraspinal muscle and fat). Kameyama, et al [ 16 ] showed a significant correlation between the fat infiltration rate assessed using MRI and muscle density assessed using CT, and both showed a significant correlation in the assessment of the CSA of the paraspinal muscles. CT is easier to use in the clinical setting because of its simplicity and reproducibility (Fig.…”

“… Kameyama et al 16 ] applied the summary method, as proposed by previous authors, to measure the cross-sectional area and muscle density on CT axial images of the paraspinal muscles. A: multifidus; B: erector spinae; C: lumbaris major.…”