Back muscle changes after pedicle based dynamic stabilization

Electroacupuncture alleviates multifidus muscle injury by modulating mitochondrial function and Ca2+ uptake

Multifidus muscles maintain the stability of the lumbar spine and play a crucial role in the pathogenesis of nonspecific lower back pain. Previous studies have shown that electroacupuncture (EA) can relieve the symptoms of low back pain and reduce injury to the lumbar multifidus muscles. In this study, a rat model of lumbar multifidus muscle injury was established by 0.05% bupivacaine injection and subsequently treated with EA at bilateral "Weizhong" (BL40) acupoints. Disruption of the function and structure of multifidus muscles, increased cytosolic Ca2+ in multifidus myocytes, and reduced mitochondrial fission and ATP production were observed in the model group. Additionally, increased expression of the mitochondrial calcium uniporter (MCU) promoted mitochondrial reuptake of Ca2+ , reversing the excessive increase in cytoplasmic Ca2+ . However, the excessive increase in MCU not only aggravated the increased cytoplasmic Ca2+ but also decreased the expression of the mitochondrial division proteins dynamin-related protein 1 (Drp1) and mitochondrial fission factor (MFF). EA inhibited the overexpression of MCU, promoted mitochondrial reuptake of Ca2+ , and reversed cytosolic Ca2+ overload. Furthermore, EA regulated the expression of the mitochondrial fission proteins Drp1 and MFF and promoted the production of ATP, helping the recovery of mitochondrial function after multifidus injury. Therefore, EA can protect against bupivacaine-induced mitochondrial dysfunction, possibly by attenuating MCU overexpression in the inner mitochondrial membrane and reducing Ca2+ overloading in muscle cells, thereby protecting mitochondrial function and maintaining the normal energy demand of muscle cells.

Effects of posterior lumbar nonfusion surgery with isobar devices versus posterior lumbar interbody fusion surgery on clinical and radiological features in patients with lumbar degenerative diseases: a meta-analysis

Purpose

The aim of this study was to systematically evaluate the efficacy of posterior lumbar isobar nonfusion with isobar devices versus posterior lumbar interbody fusion (PLIF) in the treatment of patients with lumbar degenerative diseases (LDDs).

Materials and method

We performed a literature review and meta-analysis in accordance with the Cochrane methodology. The analysis included a Group Reading Assessment and Diagnostic Evaluation assessments, Jadad Quality Score evaluations, and Risk of Bias in Randomized Studies of Interventions assessments. The PubMed, Ovid, EMBASE, Web of Science, MEDLINE, CNKI, VIP and WanFang databases were searched to collect and compare relevant randomized controlled trials and cohort studies of isobar nonfusion and PLIF in the treatment of lumbar degenerative diseases. The retrieval time was from database inception to June 2021. Two evaluators independently screened the literature, extracted data, and evaluated the quality of the included studies. Outcome measures of interest included low back pain, disability, and radiological features. The protocol for this systematic review was registered on INPLASY (2021110059) and is available in full on inplasy.com (https://inplasy.com/inplasy-2021-11-0059/).

Results

Of the 7 RCTs, 394 patients met the inclusion criteria. The meta-analysis results showed that isobar nonfusion surgery shortened the surgical duration (P = 0.03), reducing intraoperative bleeding (P = 0.001), retained the ROM of surgical segment (P < 0.00001) and the ROM of the lumbar spine (P < 0.00001), and reduced the incidence of ASD (P = 0.0001). However, no significant difference in the postoperative ODI index (P = 0.81), VAS score of LBP (P = 0.59, VAS score of lower limb pain (P = 0.05, and JOA score (P = 0.27) was noted.

Conclusions

Posterior lumbar nonfusion surgery with isobar devices is superior to PLIF in shortening the surgical duration, reducing intraoperative bleeding, retaining the ROM of surgical segments and the lumbar spine to a certain extent, and preventing ASD. Given the possible publication bias, we recommend further large-scale studies.

Clinical Correlation between Muscle Damage and Oswestry Disability Index Score after Open Lumbar Surgery: Does Open Surgery Reduces Functional Ability?

STUDY DESIGN

Single-surgeon, single-center prospective study with prospective data collection.

PURPOSE

To clinically evaluate muscle damage after open lumbar surgery and its relationship to functional activity and to validatethe improvement in function as indicated by improved Oswestry Disability Index (ODI) score despite muscle damage.

OVERVIEW OF LITERATURE

Few studies have analyzed the functional loss and recovery pattern of muscles after open lumbar surgery.

METHODS

The study included 30 patients who underwent open lumbar spine fusion surgery at our institution between August 2013 and May 2015. Preoperatively and at 6 months postoperatively, the patients were subjected to functional, biochemical, electrophysiological, and radiological assessments as outpatients, and the results were compared.

RESULTS

Mean preoperative and 6-month postoperative values were as follows: creatine phosphokinase levels, 133.07±17.57 and 139±17.7 U/L (p <0.001); Visual Analog Scale scores for backache, 6.73±0.88 and 3.27±0.96 (p <0.001); and ODI scores, 41.6±5.51 and 22.4±4.48 (p <0.001), respectively. Preoperatively, electrophysiological studies showed that 20% of the patients had a polyphasic configuration whereas at 6 months postoperatively, all patients had polyphasic configuration (p <0.001). The mean cross-sectional area of the multifidus observed using magnetic resonance imaging (MRI) decreased from 742.67±76.62 mm² preoperatively to 598.27±66.38 mm² 6 months postoperatively (p <0.001), with all the patients exhibiting grade 2 atrophy.

CONCLUSIONS

Open lumbar fusion surgery resulted in significant damage to the lumbar paraspinal muscles, as indicated by a reduction in the cross-sectional area of the multifidus by MRI and denervation of the multifidus demonstrated using electromyography. Nevertheless, the patients reported reduced back pain and improved quality of life, which may have been due to increased stability of the previously unstable lumbar spinal segment after the surgery.

Early Impact of Postoperative Bracing on Pain and Quality of Life After Posterior Instrumented Fusion for Lumbar Degenerative Conditions: A Randomized Trial

STUDY DESIGN

A randomized controlled trial.

OBJECTIVE

To investigate whether bracing after posterior spinal instrumented fusion (PSIF) can improve pain relief and quality of life (QoL) 6 weeks and 3 months postoperatively.

SUMMARY OF BACKGROUND DATA

Braces are commonly prescribed after PSIF in patients with lumbar degenerative conditions with the aim of improving pain relief and QoL. However, there is a lack of evidence on the indication for postoperative bracing, as surgeons use braces mainly based on their experience and training.

METHODS

A randomized blinded and controlled trial of 43 patients with PSIF for lumbar degenerative conditions were recruited. The caregivers were blinded but not the orthotist in the present study. There were 25 patients in the brace group and 18 patients in the control group with similar baseline characteristics. All patients completed the Oswestry Disability Index (ODI), the short form (SF)-12v2 General Health Survey and Visual Analog Scale (VAS) for back pain preoperatively, at 6 weeks and 3 months follow-up. Wilcoxon-Mann-Whitney test and a level of significance of 0.05 were used for statistical analyses.

RESULTS

Both groups had comparable demographic characteristics, and preoperative SF-12v2, ODI, and VAS scores. The ODI, SF-12v2, and VAS for back pain were improved in comparison to preoperative scores. The improvement was significant at 3 months follow-up regarding ODI and VAS for both groups and significant only for the control group regarding SF-12v2 scores. The improvement in ODI, SF-12v2, and VAS was significantly greater for control group at 3 months postoperatively. Moreover, larger proportion of patients in the control group reached minimum clinically important difference as compared to brace group at 6 weeks and 3 months.

CONCLUSION

Postoperative bracing did not result in better improvement in QoL or pain relief up to 3 months after PSIF in patients with lumbar degenerative conditions.

LEVEL OF EVIDENCE

1.

Dynamic stabilization using the Dynesys system versus posterior lumbar interbody fusion for the treatment of degenerative lumbar spinal disease: a clinical and radiological outcomes-based meta-analysis

OBJECTIVE The Dynesys, a pedicle-based dynamic stabilization (PDS) system, was introduced to overcome the drawbacks of fusion procedures. Nevertheless, the theoretical advantages of PDS over fusion have not been clearly confirmed. The aim of this study was to compare clinical and radiological outcomes of patients who underwent PDS using the Dynesys system with those who underwent posterior lumbar interbody fusion (PLIF). METHODS The authors searched PubMed, Embase, Web of Science, and the Cochrane Database. Studies that reported outcomes of patients who underwent PDS or PLIF for the treatment of degenerative lumbar spinal disease were included. The primary efficacy end points were perioperative outcomes. The secondary efficacy end points were changes in the Oswestry Disability Index (ODI) and back and leg pain visual analog scale (VAS) scores and in range of motion (ROM) at the treated and adjacent segments. A meta-analysis was performed to calculate weighted mean differences (WMDs), 95% confidence intervals, Q statistics, and I(2) values. Forest plots were constructed for each analysis group. RESULTS Of the 274 retrieved articles, 7 (which involved 506 participants [Dynesys, 250; PLIF, 256]) met the inclusion criteria. The Dynesys group showed a competitive advantage in mean surgery duration (20.73 minutes, 95% CI 8.76-32.70 minutes), blood loss (81.87 ml, 95% CI 45.11-118.63 ml), and length of hospital stay (1.32 days, 95% CI 0.23-2.41 days). Both the Dynesys and PLIF groups experienced improved ODI and VAS scores after 2 years of follow-up. Regarding the ODI and VAS scores, no statistically significant difference was noted according to surgical procedure (ODI: WMD 0.12, 95% CI -3.48 to 3.72; back pain VAS score: WMD -0.15; 95% CI -0.56 to 0.26; leg pain VAS score: WMD -0.07; 95% CI -0.47 to 0.32). The mean ROM at the adjacent segment increased in both groups, and there was no substantial difference between them (WMD 1.13; 95% CI -0.33 to 2.59). Although the United States is the biggest market for Dynesys, no eligible study from the United States was found, and 4 of 8 enrolled studies were performed in China. The results must be interpreted with caution because of publication bias. During Dynesys implantation, surgeons have to decide the length of the spacer and cord pretension. These values are debatable and can vary according to the surgeon's experience and the patient's condition. Differences between the surgical procedures were not considered in this study. CONCLUSIONS Fusion still remains the method of choice for advanced degeneration and gross instability. However, spinal degenerative disease with or without Grade I spondylolisthesis, particularly in patients who require a quicker recovery, will likely constitute the main indication for PDS using the Dynesys system.

Clinical Experiences of Non-fusion Dynamic Stabilization Surgery for Adjacent Segmental Pathology after Lumbar Fusion

BACKGROUND

As an alternative to spinal fusion, non-fusion dynamic stabilization surgery has been developed, showing good clinical outcomes. In the present study, we introduce our surgical series, which involves non-fusion dynamic stabilization surgery for adjacent segment pathology (ASP) after lumbar fusion surgery.

METHODS

Fifteen patients (13 female and 2 male, mean age of 62.1 years) who underwent dynamic stabilization surgery for symptomatic ASP were included and medical records, magnetic resonance images (MRI), and plain radiographs were retrospectively evaluated.

RESULTS

Twelve of the 15 patients had the fusion segment at L4-5, and the most common segment affected by ASP was L3-4. The time interval between prior fusion and later non-fusion surgery was mean 67.0 months. The Visual Analog Scale and Oswestry Disability Index showed values of 7.4 and 58.5% before the non-fusion surgery and these values respectively declined to 4.2 and 41.3% postoperatively at 36 months (p=0.027 and p=0.018, respectively). During the mean 44.8 months of follow-up, medication of analgesics was also significantly reduced. The MRI grade for disc and central stenosis identified significant degeneration at L3-4, and similar disc degeneration from lateral radiographs was determined at L3-4 between before the prior fusion surgery and the later non-fusion surgery. After the non-fusion surgery, the L3-4 segment and the proximal segment of L2-3 were preserved in the disc, stenosis and facet joint whereas L1-2 showed disc degeneration on the last MRI (p=0.032). Five instances of radiologic ASP were identified, showing characteristic disc-space narrowing at the proximal segments of L1-2 and L2-3. However, no patient underwent additional surgery for ASP after non-fusion dynamic stabilization surgery.

CONCLUSION

The proposed non-fusion dynamic stabilization system could be an effective surgical treatment for elderly patients with symptomatic ASP after lumbar fusion.

Magnetic resonance imaging-based anatomical study of the multifidus-longissimus cleavage planes in the lumbar spine

PURPOSE

The Wiltse approach allows spinal surgeries to be performed with minimal soft tissue trauma. The purpose of this study was to investigate the anatomy of the natural cleavage plane between multifidus and longissimus at different levels based on MRI images.

METHODS

MRI cross-sectional scans from L1 to S1 were collected from 205 out patients (103 males, 102 females). Based on the images, some parameters were defined and measured to describe the locations, curvature and directions of Wiltse approach. Besides, differences of these parameters between genders and segments were compared.

RESULTS

Among the total of 2460 one-sided images, cleavage planes between multifidus and longissimus were not able to be identified in 105 images. The locations, directions and curvature of the cleavage plane differed significantly among different segments but followed some regular pattern from L1-S1. The simultaneous rotation of the plane around its deepest points to the midline from S1 to L1 and the plane seemed to be the most curved at L3 and relatively straight for L5 and S1.

CONCLUSIONS

With a better understanding of the natural cleavage plane between multifidus and longissimus, performers can correctly plan the distance of skin incisions from the midline and the direction of muscle dissection at each vertebral level, thus reducing trauma in the operation.

Short-term effects of a dynamic neutralization system (Dynesys) for multi-segmental lumbar disc herniation

PURPOSE

To determine the safety and short-term curative effects of internal fixation using a dynamic neutralization system (Dynesys) for multi-segmental lumbar disc herniation (ms-LDH) with the control group treated by posterior lumbar interbody fusion (PLIF).

METHODS

Forty-five patients with ms-LDH were selected as study group treated with Dynesys and 40 patients as control group with PLIF. The surgical efficacy was evaluated by comparing the visual analogue scale (VAS) scores, the Oswestry Disability Index (ODI) scores and the ROMs of the adjacent segment before and after surgery. The postoperative complications related to the implants were identified.

RESULTS

All patients were followed up for an average duration of over 30 months. Dynesys stabilization resulted in significantly higher preservation of motion at the index level (p < 0.001), and significantly less (p < 0.05) hypermobility at the adjacent segments. VAS for back and leg pain and ODI improved significantly (p < 0.05) with both the methods, but there was no significant difference between the groups.

CONCLUSIONS

The non-fusion fixation system Dynesys is safe and effective regarding short-term curative effects for the treatment of ms-LDH.