A Biomimetic Peptide Functions as Specific Extracellular Matrix for Quiescence of Stem Cells against Intervertebral Disc Degeneration.

Maintaining quiescence of stem cells is a potential way to decrease cell nutrition demand for restoring the organization. Herein, a biomimetic peptide to maintain quiescence of stem cells through C-X-C motif chemokine ligand 8 (CXCL8)-C-X-C motif chemokine receptor 1 (CXCR1) pathway against intervertebral disc degeneration (IVDD) is developed. First, it is confirmed that quiescence can be induced via inhibiting phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway in nucleus pulposus stem cells (NPSCs). Meanwhile, it is well known that CXCR1, a chemokine receptor, can be targeted by CXCL8, resulting in cell proliferation via activating PI3K/Akt/mTOR pathway. Second, a biomimetic peptide (OAFF) that can bind to CXCR1 and form fibrous networks on NPSCs, mimicking extracellular matrix formation is developed. The multivalent effect and long-term binding to CXCR1 on NPSCs of OAFF fibers offer forcefully competitive inhibition with natural CXCL8, which induces NPSCs quiescence and ultimately overcomes obstacle in intradiscal injection therapy. In rat caudal disc puncture model, OAFF nanofibers still maintain at 5 weeks after operation and inhibit degeneration process of intervertebral disc in terms of histopathology and imageology. In situ fibrillogenesis of biomimetic peptide on NPSCs provides promising stem cells for intradiscal injection therapy against IVDD.

Correlation Between Atrophy of the Gluteus Medius Muscle and Symptoms of Lumbar Spinal Stenosis.

OBJECTIVE: Lower muscular weakness and gait disturbance are typical lumbar spinal stenosis (LSS) symptoms. Gait initiation and standing balance function are dependent on hip muscle groups, particularly gluteus medius (GMed). However, alterations to GMed in patients with LSS have not been studied. Therefore, we evaluated the impact of LSS on GMed in this study. METHODS: This study included 96 participants divided into the LSS and non-LSS groups. A total of 48 patients with LSS and unilateral buttock pain underwent T2-weighted magnetic resonance imaging of GMed, and 48 age- and sex-matched controls formed the control group. Differences between the cross-sectional areas (CSAs) on both sides of GMed were compared between the 2 groups. Additionally, correlations among patient characteristics, clinical evaluation, and radiological measurement data with a decrease in the CSA of GMed were assessed in the LSS group. RESULTS: A significant difference was observed in the bilateral discrepancy of the GMed CSA between the LSS and non-LSS groups. For patients with LSS with unilateral buttock pain, 81% had reduced CSA of GMed. Regression analysis revealed that buttock pain was an independent factor related to GMed atrophy. CONCLUSIONS: The degree of GMed atrophy is related to symptoms of LSS. Spine surgeons should be aware of the risk of GMed atrophy in patients with LSS with unilateral buttock pain.

Clinical outcomes of minimally invasive transforaminal lumbar interbody fusion via a novel tubular retractor.

OBJECTIVE: To assess the feasibility and clinical results of microscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a novel tapered tubular retractor that preserves the multifidus. METHOD: A total of 122 patients underwent MIS-TLIF using a tapered tubular retractor system from March 2016 to August 2017. Perioperative parameters and follow-up outcomes were reviewed. RESULTS: The follow-up period was 23.95 ± 1.43 months. The operative time averaged 130.48 ± 34.44 minutes. The estimated blood loss was 114.10 ± 96.70 mL. The mean time until ambulation was 16.33 ± 6.29 hours. The average visual analogue scale (leg/waist) and Oswestry Disability Index scores (preoperative to last follow-up) improved from 4.93 ± 2.68/3.74 ± 2.28 to 0.34 ± 0.77/0.64 ± 0.74 and from 59.09% ± 22.34 to 17.04% ± 8.49, respectively. At the last follow-up, 98.36% of the patients achieved solid fusion. Cerebrospinal fluid leakage occurred in two cases. The asymptote of the surgeon's learning curve occurred at the 25th case. There were no significant differences between the preoperative qualitative and quantitative analyses of multifidus muscle fatty infiltration and those at the final follow-up. CONCLUSION: MIS-TLIF can be performed safely and effectively using this tapered tubular retractor system, which helps preserve the multifidus.

Comparison of Endoscope-Assisted and Microscope-Assisted Tubular Surgery for Lumbar Laminectomies and Discectomies: Minimum 2-Year Follow-Up Results.

PURPOSE: This study aimed to evaluate the clinical outcomes of endoscope-assisted and microscope-assisted tubular surgery for lumbar laminectomies and discectomies. METHODS: Three hundred and seven patients with lumbar spinal stenosis (LSS) or lumbar disc herniation (LDH) at L3-4, L4-5, and L5-S1 were included in this study. The patients were treated with endoscope-assisted or microscope-assisted tubular surgery. Data on patient demographic characteristics and operative results, including ages, blood loss, operative times, hospital stay, and surgical complications were collected. Clinical outcomes were assessed based on pre- and postoperative Visual Analog Scale (VAS) scores for low-back pain (LBP) and leg pain, Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scale. RESULTS: Both tubular-based endoscope-assisted and microscope-assisted surgery were effective in relieving acute radicular symptoms. The results showed characteristic differences in operating times between endoscope-assisted and microscope-assisted procedures and between discectomies and laminectomies. At the last follow-up, VAS scores of LBP and leg pain, JOA scores, and ODI scores were significantly better than preoperative correlates in all groups. There were no differences between endoscope-assisted and microscope-assisted discectomies for LDH in JOA scores, ODI scores, and VAS scores, while the microscope-assisted laminectomies related to better JOA recovery rate for LSS. CONCLUSIONS: Endoscope-assisted and microscope-assisted tubular discectomies resulted in similar clinical outcomes for LDH, while the microscope-assisted surgery may relate to better recovery rate for LSS, less surgical time, and less intraoperative dural tear.

Establishment and Implementation of an Enhanced Recovery After Surgery (ERAS) Pathway Tailored for Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery.

PURPOSE: The concept of enhanced recovery after surgery (ERAS) spread to different surgical specialties to minimize surgical stress response and to reduce length of hospital stay (LOS) and cost. Recently, several studies have reported experience with the ERAS program for spine surgery. The aim of this study is to introduce the establishment and implementation of the ERAS pathway for minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF). METHODS: A multidisciplinary ERAS team was created to develop and implement a multimodal and evidence-based ERAS protocol for patients undergoing MIS-TLIF at a single spine center from January 2018. Fourty four cases in the ERAS group were compared with a historical cohort of 30 cases (from January 2017 to December 2017) who underwent MIS-TLIF before the pathway implementation (pre-ERAS group). We reviewed the compliance with ERAS components. The primary outcome was LOS. The secondary outcomes included 30-day readmission rate, 30-day reoperation rate, and financial cost. Perioperative factors and perioperative complications were also assessed. RESULTS: The protocol was composed of 11 ERAS components. The ERAS group showed high compliance with the ERAS program. The ERAS group manifested shorter LOS and lower cost compared with the the pre-ERAS group. There were no significant differences in complication rate, 30-day readmission and reoperation rates. Furthermore, the blood loss, operative time, intraoperative fluid infusion and postoperative drainage of the ERAS group decreased. CONCLUSIONS: Our ERAS program tailored for MIS-TLIF is able to reduce LOS and cost with minimal complications. The ERAS pathway expedites recovery in patients undergoing lumbar spine fusion.