Paraspinal muscle atrophy after posterior lumbar surgery with and without pedicle screw fixation with the classic technique

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

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.

Endoscopic modified total laminoplasty for symptomatic lumbar spinal stenosis

Context/objective: At present, there is no consensus on the most effective surgical method for treating symptomatic lumbar spinal stenosis (LSS). Total laminectomy, which is frequently used at this time, destroys the posterior midline structure, causing many postoperative complications. We have designed a new surgical approach instead of total laminectomy. In this paper, we aimed to describe the surgical method of endoscopic modified total laminectomy for lumbar spinal stenosis as well as to explore its early efficacy.Participants: Patients with symptomatic LSS who underwent endoscopic modified total laminoplasty between August 2016 and August 2017 were eligible for our study.Outcome measures: Before surgery and one year after surgery, we measured lower limb pain and back pain by visual analog scale (VAS), disability via Oswestry Disability Index (ODI), and severity of back pain according to the Japanese Orthopedic Association Score for Back Pain (JOA), while any complications were also assessed.Results: Endoscopic modified total laminoplasty was performed on 22 LSS patients, including eight males and 14 females(mean age = 59.3 ± 9.6 years). We found statistically significant differences before and one year after surgery for VAS lower limb pain and back pain, ODI and JOA scores(P < 0.001). Complications included intraoperative dural tears(n = 1),and weak fusion between the lamina and the vertebral body (n = 1).Conclusion: Endoscopic modified total laminectomy is a promising surgical approach which reduces patient suffering and improves patient quality of life.

Research Progress on the Mechanism of Lumbarmultifidus Injury and Degeneration

This review summarizes recent research progress in the clinical features, image manifestations, and pathological mechanism of multifidus injury. After a brief introduction to the fiber classification, innervation, blood supply, and multifidus function, some factors of multifidus injury, consisting of denervation, intraoperative incision selection and traction, and lumbar degenerative disease are overviewed. In addition, the clinical index of multifidus injury including myoglobin, creatine kinase, IL-6, C-reactive protein, the cross-sectional area of multifidus, the degree of fat infiltration, and intraoperative biopsy are summarized. Furthermore, we recommend that patients with chronic low back pain should take the long-term exercise of lumbodorsal muscles. Finally, some remaining issues, including external fixation and the imaging quantitative evaluation criteria of multifidus, need to be further explored in the future.