Comparison of percutaneous endoscopic interlaminar discectomy and conventional open lumbar discectomy for L4/5 and L5/S1 double-segmental lumbar disk herniation.

OBJECTIVE: Although spinal endoscopic techniques have shown great advantages in the treatment of single-segment lumbar disk herniation (LDH), the therapeutic advantages for double-segment LDH are controversial. To compare the outcomes of percutaneous endoscopic interlaminar discectomy (PEID) versus conventional open lumbar discectomy (COLD) for the treatment of L4/5 and L5/S1 double-segmental LDH. METHODS: From January 2016 to September 2021, we included 50 patients with double-segmental LDH who underwent PEID (n = 25) or COLD (n = 25). The clinical outcomes between the two groups were evaluated using the visual analog scale (VAS), the Oswestry disability index (ODI), and the modified MacNab criteria. Moreover, the incision length, operation time, intraoperative fluoroscopy time, postoperative bedtime, hospital stays, and complications were also recorded and compared after surgery. RESULTS: In both groups, the VAS and ODI scores at different timepoints postoperatively were significantly improved compared with those preoperatively (P < 0.05) According to the modified MacNab criteria, the excellent or good outcome rate was 92% in the PEID group and 88% in the COLD group. The PEID group had shorter incision length, postoperative bedtime, and hospital stays than the COLD group. However, the operation time was shorter and intraoperative fluoroscopy time was fewer in the COLD group. In addition, there was no significant difference between the two groups in terms of surgical complications during the postoperative follow-up period. CONCLUSIONS: Both PEID and COLD have good efficacy and high safety for management of L4/5 and L5/S1 double-segmental LDH. Compared with the COLD group, the PEID group had more operative time as well as more intraoperative fluoroscopy, but it had a more minimally invasive surgical incision as well as faster postoperative recovery.

Melatonin suppresses bone marrow adiposity in ovariectomized rats by rescuing the imbalance between osteogenesis and adipogenesis through SIRT1 activation.

Introduction: Accelerated imbalance between bone formation and bone resorption is associated with bone loss in postmenopausal osteoporosis. Studies have shown that this loss is accompanied by an increase in bone marrow adiposity. Melatonin was shown to improve impaired bone formation capacity of bone marrow-derived mesenchymal stem cells from ovariectomized rats (OVX-BMMSCs). Objectives: To investigate whether the anti-osteoporosis effect of melatonin involves regulation of the equilibrium between osteogenic and adipogenic differentiation of osteoporotic BMMSCs. Methods: To induce osteoporosis, female Sprague-Dawley rats received ovariectomy (OVX). Primary BMMSCs were isolated from tibiae and femurs of OVX and sham-op rats and were induced towards osteogenic or adipogenic differentiation. Matrix mineralization was determined by Alizarin Red S (ARS) and lipid formation was evaluated by Oil Red O. OVX rats were injected with melatonin through the tail vein. Bone microarchitecture was determined using micro computed tomography and marrow adiposity were examined by histology staining. Results: OVX-BMMSCs exhibited a compromised osteogenic potential and an enhanced lineage differentiation towards adipocytes. In vitro melatonin improved osteogenic differentiation of OVX-BMMSCs and promoted matrix mineralization by enhancing the expression of transcription factor RUNX2 in a dose-dependent manner. Moreover, melatonin significantly inhibited lipid formation and suppressed OVX-BMMSCs adipogenesis by down-regulating peroxisome proliferator-activated receptor γ (PPARγ). Intravenous injection of melatonin prevented bone mass reduction and bone architecture destruction in ovariectomized rats. Importantly, there was a significant inhibition of adipose tissue formation in the bone marrow. Mechanistic investigations revealed that SIRT1 was involved in melatonin-mediated determination of stem cell fate. Inhibition of SIRT1 abolished the protective effects of melatonin on bone formation by inducing BMMSCs towards adipocyte differentiation. Conclusions: Melatonin reversed the differentiation switch of OVX-BMMSCs from osteogenesis to adipogenesis by activating the SIRT1 signaling pathway. Restoration of stem cell lineage commitment by melatonin prevented marrow adipose tissue over-accumulation and protected from bone loss in postmenopausal osteoporosis. The translational potential of this article: Determination of stem cell fate towards osteoblasts or adipocytes plays a pivotal role in regulating bone metabolism. This study demonstrates the protective effect of melatonin on bone mass in estrogen-deficient rats by suppressing adipose tissue accumulation in the bone marrow. Melatonin may serve as a promising candidate for the treatment of osteoporosis in clinics.

Melatonin Improves the Resistance of Oxidative Stress-Induced Cellular Senescence in Osteoporotic Bone Marrow Mesenchymal Stem Cells.

Accumulation of senescent bone marrow-derived mesenchymal stem cells (BMMSCs) has led to an age-related bone loss. However, the role of stem cell senescence in estrogen deficiency-induced osteoporosis remains elusive. Though melatonin plays a vital role in bone metabolism regulation, the underlying mechanisms of melatonin-mediated antiosteoporosis are partially elucidated. Therefore, this study purposed to explore (1) whether estrogen deficiency causes cellular senescence of BMMSCs, and if so, (2) the potential of melatonin in preventing bone loss via senescence signaling inhibition. BMMSCs derived from ovariectomized (OVX) rats (OVX BMMSCs) showed an impaired osteogenic capacity, albeit having comparable levels of senescence biomarkers than the sham cells. When exposed to low levels of hydrogen peroxide (H2O2), OVX BMMSCs rapidly exhibited senescence-associated phenotypes such as the increased activity of senescence-associated ß-galactosidase (SA-ß-gal) and upregulation of cell cycle inhibitors. Notably, the in vitro treatment with melatonin hindered H2O2-induced senescence in OVX BMMSCs and restored their osteogenic capacity. Treatment with either SIRT1 inhibitor (sirtinol) or melatonin receptor antagonists (luzindole and 4-P-PDOT) eliminated melatonin protective effects, thus indicating its potential in preventing stem cell senescence via SIRT1 activation through the melatonin membrane receptors. Following in vivo intravenous administration with melatonin, it successfully protected the bone microstructure and preserved the antisenescence property of BMMSCs in OVX rats. Collectively, our findings demonstrated that melatonin protected against estrogen deficiency-related bone loss by improving the resistance of BMMSCs to cellular senescence. Therefore, melatonin-mediated antisenescence effect on stem cells provides vital information to facilitate the development of a novel and effective strategy for treating postmenopausal OP.

Andersson Lesion Occurring in the Lumbosacral Segment of a Young Man: A Case Report and Literature Review.

BACKGROUND: Andersson lesion (AL) is not a rare complication of ankylosing spondylitis (AS), but it seldom occurs in single lumbosacral segments or young people. We present a case of a young patient with AS and AL between L5 and S1. CASE DESCRIPTION: A 30-year-old man with a history of AS presented with AL between L5 and S1. Surgery performed under O-arm navigation was successful. At 6-month follow-up, the patient's pain was reduced, and his function had improved. CONCLUSIONS: AL rarely occurs in the lumbosacral region or in young people and can be misdiagnosed as spinal tuberculosis. Surgical treatment of AL aims to relieve spinal nerve compression, reconstruct spinal stability, and restore sagittal balance. In view of the ambiguous anatomic landmark of patients with AS, we recommend surgery assisted with O-arm navigation, which clearly showed the entry point and guaranteed the accuracy of pedicle screw placements.

Comparison of Polyaxial or Poly/Monoaxial Mixed Screw Fixation for Treatment of Thoracolumbar Fractures with O-Arm Navigation: A Case-Control Study.

BACKGROUND: Navigation and minimally invasive techniques have revolutionized spinal surgery. There are different types of pedicle screws for navigation-assisted percutaneous internal fixation for thoracolumbar burst fractures, resulting in 2 different types of internal fixation approaches: the PPP method (polyaxial screw fixation for all 3 vertebrae) and the MPM method (polyaxial screw fixation for the injured vertebra and monoaxial screw fixation for the adjacent vertebrae). This study aims to compare these 2 different methods for treatment of thoracolumbar fractures via O-arm navigation. METHODS: From January 2017 to January 2018, 45 patients were enrolled according to the criteria with a minimal follow-up of 1 year; there were 21 patients in the PPP group, and 24 patients in the MPM group. For follow-up, the demographic features and clinical outcomes were collected and evaluated. RESULTS: With regard to preoperative indices and demographic features, no significant difference was observed between these 2 groups (P > 0.05). For operation time, intraoperative bleeding, and length of hospitalization, no significant difference was observed either between the 2 groups (P > 0.05). The Cobb angle and anterior vertebrae body height (AVBH) of the injured vertebra were significantly restored in both groups 1 day after surgery (P < 0.05). However, the Cobb angle and AVBH in the MPM group was better corrected than that in the PPP group 1 day, 3 months, and 12 months after surgery, respectively (P < 0.05). In contrast, loss of Cobb angle and AVBH in the PPP group were significantly larger than the MPM group (P < 0.05). Meanwhile, no difference in the Visual Analog Scale and the Oswestry Disability Index were found between the 2 groups (P > 0.05). CONCLUSIONS: Both MPM and PPP systems are good for treatment of single-segment thoracolumbar fracture. However, MPM showed better restoration effect and postoperative maintained Cobb angle than PPP.

The Influence of Diabetes Mellitus on Patients Undergoing Primary Total Lower Extremity Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Diabetes mellitus (DM) is a common disease that has an adverse impact on most orthopedic surgeries, and its prevalence has gradually increased in recent years. We aim to investigate the influence of DM on comorbidities and complications of patients undergoing primary total lower extremity arthroplasty. METHODS: PubMed, Embase, Cochrane Library, Medline, and Web of Science were systematically searched for relevant studies published before December 2019. Demographic data, comorbidities, and postoperative complications after primary total hip arthroplasties (THA) or primary total knee arthroplasties (TKA) were assessed between DM and non-DM patients. Meta-analysis was conducted using Review Manager 5.3, and forest plots were drawn for each variable. RESULTS: A total of 1,560,461 patients (215,916 patients with DM and 1,344,545 patients without DM) from 23 studies were included in this meta-analysis. The incidences of several preoperative comorbidities (hypertension (HTN), kidney disease, cardiac and cerebrovascular disease) were generally higher in patients with DM. Moreover, DM patients had a higher rate of postoperative complications (superficial and deep infection, deep vein thrombosis (DVT), and in-hospital mortality) compared to non-DM patients. CONCLUSIONS: DM patients were more likely to suffer from comorbidities and had a higher risk of complications in total lower extremity arthroplasty compared to non-DM patients. It is necessary to identify DM and control hyperglycemia in the perioperative period to prevent postoperative complications in patients with DM.