The recovery of damaged paraspinal muscles by posterior surgical treatment for patients with lumbar degenerative diseases and its clinical consequence

Lyophilized bovine acellular tendon linear fiber material for the reconstruction of attachment structure of paraspinous muscles: an animal in vivo study

Low back pain is common after lumbar spine surgery and the injury from extensive detachment of paraspinal muscles during the surgery may play a vital role. Previously, we prepared a bovine acellular tendon fiber (ATF) material through lyophilization and proved that it could retain its original fibrillar structure and mechanical properties. The objective of this study is to evaluate the effectiveness of this new fiber material used for attachment structure reconstruction of paraspinal muscle. Defect of spinous process, interspinous and supraspinous ligament was established on lumbar spine in rabbit and rat and ATF linear material was implanted to reconstruct the attachment structure. Ultrasound showed the cross-sectional area of the paraspinal muscle in ATF group was larger than that of control group in rats. MRI showed the irregular shape and high signal changes in control group, but regular shape and uniform signal in the ATF group in rabbit. For Electromyogram, the frequency of evoked potential in control group was lower than ATF group and normal rats. HE and Masson staining showed good tissue healing, and immunohistochemical results showed the immune rejection of ATF is significantly lower than that of suture. Reconstruction of the attachment structure of paraspinous muscles with ATF linear material could maintain the morphology, volume and function of paraspinal muscle. ATF material has the potential to be used to manufacture personalized ligaments and other tissue engineering scaffolds. Graphical abstract.

Microscopic Unilateral Approach for Bilateral Decompression of Lumbar Spinal Stenosis

BACKGROUND

This is a study based on single-surgeon data on spinal stenosis surgery via microscopic approach. The aim is to evaluate the effectiveness of the unilateral approach to bilateral decompression and the usage of Taylor retractors and brain spatula in patients with spinal stenosis.

METHODS

This is a retrospective study on bilateral decompression for lumbar spinal stenosis using a microscopic unilateral approach by a single surgeon, between April 2015 and March 2018. In total, 50 patients were operated due to single level lumbar spinal stenosis. All patients were evaluated by preoperative and postoperative plain radiographs and magnetic resonance (MR) images. Walking distance (WD), visual analog scale (VAS) for pain and Odom's criteria were evaluated for follow-up.

RESULTS

One level of the lumbar spine was surgically decompressed in all patients. The median age of patients was 64.6 (51- 82). Of the patients, 72% (36) were women, and 28% (14) were men. Most patients had refractory low back pain (96%) after conservative treatment. The stenotic levels of the cases were as follows: L3-4, 23(46%); L4-5, 24(48%); and L5-S1, 3 (6%). VAS scores decreased in all patients after surgery. According to Odom's criteria, an excellent or good score was found in 43 patients at the 12th follow-up examination. WDs increased up to 1000 meters for 41 patients.

CONCLUSION

The microscopic unilateral approach to bilateral decompression is an effective method for decompression in spinal stenosis. Via this approach, surgical trauma is reduced and surgically induced instability is avoided as much as possible.

Assessment of the psoas muscle changes following the oblique lateral interbody fusion (OLIF) approach: A prospective observational study

Background

Traditional open posterior fusion techniques involve stripping of the posterior paraspinal muscles with protracted retraction, which can lead to ischemia and denervation. This may result in poor clinical outcomes despite a well-performed surgery. Oblique lumbar interbody fusion (OLIF) is a minimally invasive modified retroperitoneal anterior approach in the corridor between the psoas major (PM) and great vessels. The purpose of this research was to study changes in psoas properties and clinical outcomes in terms of the loss of hip flexion in patients undergoing OLIF surgery.

Methods

Patients with lumbar pathologies who underwent instrumented OLIF at our center were included. These patients were examined clinically at baseline and 6 months postoperatively. The Oswestry disability index (ODI) and visual analog scale (VAS) scores for back pain and leg pain were noted. Magnetic resonance imaging (MRI) scans were obtained preoperatively and postoperatively (minimum 6 months) to compare the cross-sectional areas (CSAs) of the PM.

Results

In total, 17 patients (male: female = 8:9) with a mean age of 46.06 ± 10.49 years were included. The operation time was 154.94 ± 32.33 min, estimated blood loss was 190 ± 56 mL, and mean CSAs of the right and left psoas were, respectively, 9.94 ± 3.19 and 10.65 ± 3.74 cm2 preoperatively and 10.00 ± 3.06 and 8.53 ± 2.81 cm2 at follow-up. Qualitative measurements revealed that muscle atrophy on the left side (approach side) was 19.12% ± 3.14% and fatty degeneration had occurred in 13 of 17 (76.5%) patients. Postoperatively, all patients had significant improvement in the VAS (back and leg) and ODI scores. Furthermore, 3 of 17 (17.6%) patients had mild hip weakness (4/5) on the left side immediately postoperatively, but it resolved in 6 months. Moreover, 2 of 17 (11.8%) patients complained of paraesthesia.

Conclusion

OLIF does cause injury to the PM but it is clinically insignificant according to MRI scans and clinical evaluations.

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.

Magnetic Resonance Imaging of Trunk Musculature and Intervertebral Discs in Patients with Spinal Cord Injury with Thoracolumbar Vertebral Fractures: A Prospective Study

Study Design

This study is a prospective clinical study.

Purpose

This study aims to evaluate the characteristics of trunk musculature and intervertebral discs by using magnetic resonance imaging in patients with spinal cord injuries (SCIs) with thoracic and lumbar fractures.

Overview of Literature

Muscle atrophy is an immediate consequence of SCI and is associated with secondary complications. At present, there are limited clinical data on muscle and disc responses to fractures of the thoracic and lumbar spine.

Methods

A total of 51 patients with a mean age of 31.75±10.42 years who suffered traumatic SCI were included in this study. Complete neurological examinations (American Spinal Injury Association grading) and magnetic resonance imaging (MRI) were performed at the time of admission and at 3–6 months after injury to study the neurological status and disc and trunk parameters. The type of management (operative or conservative) was decided on the basis of clinical, radiological, and MRI evaluations, and a robust rehabilitation program was initiated.

Results

Disc parameters including disc angle, skin angle, cross-sectional area (CSA), and disc height and trunk parameters (mean trunk width, mean trunk depth, and CSA of the lumbar muscles) decreased significantly (p <0.001) during the first 3 months after SCI. However, improvements were observed in disc and muscle parameters at the 6-month follow-up, but these parameters did not return to normal levels. Neither initial neurological status (complete vs. incomplete) nor type of management (operative vs. conservative) had a significant effect on these parameters.

Conclusions

Spinal trauma leads to alterations in the morphology of the vertebral column, spinal cord, intervertebral discs, and paraspinal muscles in the initial phase of injury. The extent of these changes may determine the initial neurological deficit and subsequent recovery. Although this study did not identify any statistically significant effect of neurological status or management strategy on these parameters, rehabilitation was found to result in the improvement of these parameters in the later phase of recovery. Future studies are required to evaluate the exact causes of these alterations and the potential benefits of rehabilitation strategies and to minimize these changes.