The role of cells and signal pathways in subchondral bone in osteoarthritis.

Osteoarthritis (OA) is mainly caused by ageing, strain, trauma, and congenital joint abnormalities, resulting in articular cartilage degeneration. During the pathogenesis of OA, the changes in subchondral bone (SB) are not only secondary manifestations of OA, but also an active part of the disease, and are closely associated with the severity of OA. In different stages of OA, there were microstructural changes in SB. Osteocytes, osteoblasts, and osteoclasts in SB are important in the pathogenesis of OA. The signal transduction mechanism in SB is necessary to maintain the balance of a stable phenotype, extracellular matrix (ECM) synthesis, and bone remodelling between articular cartilage and SB. An imbalance in signal transduction can lead to reduced cartilage quality and SB thickening, which leads to the progression of OA. By understanding changes in SB in OA, researchers are exploring drugs that can regulate these changes, which will help to provide new ideas for the treatment of OA.

Biomechanical effects of reconstruction of the posterior structures after laminectomy with an individualized poly-ether-ether-ketone (PEEK) artificial lamina.

BACKGROUND: Laminectomy is a traditional method for treating lumbar diseases; however, the destruction of the posterior structures may cause postoperative symptoms. An individualized poly-ether-ether-ketone (PEEK) artificial lamina was designed to reconstruct the posterior structures after laminectomy. This study aimed to explore the biomechanical effects of reconstruction of the posterior structures with an individualized PEEK artificial lamina using validated finite element models. OBJECTIVE: To examine the biomechanical effects of individualized PEEK artificial lamina on postlaminectomy lumbar. METHODS: A finite element (FE) model of L3-5 was developed based on computed tomography images. Four surgical models (laminectomy, artificial lamina alone, ligament reconstruction, and osseointegration) were constructed, representing different stages of L4 artificial lamina implantation. The range of motion (ROM), intradiscal pressure (IDP), stresses in the annulus fibrosus at the surgical level and cephalad adjacent level, and stresses in the artificial lamina and screws were measured. RESULTS: The ROM, IDP, and stresses in the annulus fibrosus of the different artificial lamina models decreased compared to those of the laminectomy model at both surgical and adjacent levels for all motion patterns, most notably in the osseointegration model. In addition, the results of the stresses in the implants showed that the artificial lamina could enhance the lumbar isthmus and disperse the abnormally concentrated stresses after laminectomy. CONCLUSION: The application of a PEEK artificial lamina has the potential to stabilize the postlaminectomy lumbar spine and prevent adjacent segment disease (ASD) and iatrogenic lumbar deformities, resulting in a reduction in the incidence of post-lumbar surgery syndrome.

Is It Possible to Replace Microendoscopic Discectomy with Percutaneous Transforaminal Discectomy for Treatment of Lumbar Disc Herniation? A Meta-Analysis Based on Recurrence and Revision Rate.

OBJECTIVES: Due to recent developments and the wide application of percutaneous transforaminal discectomy (PTED) in China, we herein compare its clinical effects with microendoscopic discectomy (MED) for the treatment of lumbar disc herniation in terms of recurrence and revision rates. METHODS: Six databases, namely, PubMed, EMBASE, Cochrane Library, Ovid, China National Knowledge Infrastructure and Wanfang, were searched by computer. The literature was screened according to inclusion and exclusion criteria, and the quality of the included literature was evaluated. After extracting the data from the papers, Review Manager 5.2 software (Cochrane Collaboration, Oxford, UK) was applied to analyze these data. Finally, sensitivity and publication bias analyses of the results were conducted. RESULTS: A total of 12 studies consisting of 2400 patients were included in this meta-analysis. A comparison of PTED with MED revealed higher postoperative recurrence and postoperative revision rates for PTED (odds ratio [OR] recurrence, 1.60; 95% confidence interval [CI], 1.01 to 2.53; p=0.05 and OR revision, 1.77; 95% CI, 1.18 to 2.64, p=0.006). CONCLUSION: PTED has a number of advantages because it is a minimally invasive surgery, but its recurrence and revision rates are higher than MED. Therefore, MED should not be completely replaced by PTED.

Mesenchymal Stem Cell (MSC)-Derived Extracellular Vesicles: Potential Therapeutics as MSC Trophic Mediators in Regenerative Medicine.

Mesenchymal stem cells (MSCs) are pluripotent progenitor cells with the capabilities of self-renewing, differentiating into multiple lineages, and achieving trophic effects during tissue repair. MSCs can secrete extracellular vesicles (EVs) including exosomes and microvesicles, which mediate their trophic effects on other cells. Carrying a variety of intracellular molecules of MSCs including lipids, proteins, RNA (mRNA and noncoding RNA), and DNA, EVs deliver them into other cells to regulate tissue regeneration process. The therapeutic effects of MSC-derived EVs have been observed in a number of animal disease models. In this review, we focus on the current state and future directions of MSC-derived EVs in regenerative medicine. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

TRAIL gene 1595C/T polymorphisms contribute to the susceptibility and severity of intervertebral disc degeneration: a data synthesis.

BACKGROUND: Studies have investigated the correlation between tumor necrosis factor related apoptosis-inducing ligand (TRAIL) gene polymorphisms and the susceptibility and severity of intervertebral disc degeneration (IDD), but the results were inconsistent. To evaluate the specific relationship, we performed a meta-analysis to clarify the controversies. METHODS: Four databases were searched, and the pooled results were presented as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Three case-control studies from Han Chinese were included (565 cases and 427 controls). All the included studies reported TRAIL 1595C/T gene polymorphisms. The recessive model (CC vs. CT + TT) was the optimal model, which demonstrated a significant relationship between 1595C/T polymorphisms and increased IDD risk (OR = 2.18, 1.45 to 3.27, P = 0.000). No significant heterogeneity was found in the recessive model (I2 = 48.6%, P = 0.143). Patients with lower grade IDD had more genotypes or alleles including 1595TT genotype (grade II vs. grade III: OR = 2.12, 1.18 to 3.83, P = 0.012; grade III vs. grade IV: OR = 2.59, 1.29 to 5.22, P = 0.007) and 1595 T allele (grade II vs. grade III: OR = 1.91, 1.43 to 2.55, P = 0.000; grade II vs. grade IV: OR = 2.46, 0.94 to 1.76, P = 0.000). CONCLUSIONS: There is a significant relationship between 1595C/T polymorphisms and the susceptibility and severity of IDD in Han Chinese. Patients with lower grade IDD had higher frequency of the 1595TT genotype and 1595 T allele.

Posterior atlantoaxial fusion with a screw-rod system: Allograft versus iliac crest autograft.

OBJECTIVE: To compare the effectiveness of allograft and iliac crest autograft in atlantoaxial fusion. PATIENTS AND METHODS: Between January 2012 and December 2012, 41 consecutive patients underwent posterior atlantoaxial fusion with a screw-rod fixation system in our spine center. The choice to use allograft or iliac crest autograft was made by the patient himself or herself after being informed about the advantages and disadvantages of both methods. In the allograft group, we used mixed material of morcellized demineralized freeze-dried bone allograft and local autograft for posterior atlantoaxial fusion. In the autograft group, we used the morcellized iliac crest autograft for fusion. Patients underwent regular follow up including CT scans and dynamic radiographs 6 months postoperatively and every 6 months thereafter until study completion or confirmation of fusion. RESULTS: Twenty-four patients underwent posterior atlantoaxial fusion with allograft, and 17 underwent fusion with autograft. All patients were followed up for at least 24 months. At the final follow-up visit, only two (8.3%) patients in the allograft group had confirmed posterior bony fusion on CT imaging while 15 (88.2%) patients in the autograft group had confirmed posterior bony fusion. None of the 41 patients had movement on the dynamic radiographs. CONCLUSIONS: Allograft is not reliable for posterior atlantoaxial fusion even with the rigid internal fixation of modern constructs. Autograft remains the first choice for atlantoaxial fusion despite the donor-site morbidity. The assessment of fusion based on a lack of movement on dynamic radiographs is not reliable. The confirmation of fusion should be based on the presence of bridging bone on CT imaging.

Acupuncture for musculoskeletal pain: A meta-analysis and meta-regression of sham-controlled randomized clinical trials.

The aims of this systematic review were to study the analgesic effect of real acupuncture and to explore whether sham acupuncture (SA) type is related to the estimated effect of real acupuncture for musculoskeletal pain. Five databases were searched. The outcome was pain or disability immediately (≤1 week) following an intervention. Standardized mean differences (SMDs) with 95% confidence intervals were calculated. Meta-regression was used to explore possible sources of heterogeneity. Sixty-three studies (6382 individuals) were included. Eight condition types were included. The pooled effect size was moderate for pain relief (59 trials, 4980 individuals, SMD -0.61, 95% CI -0.76 to -0.47; P < 0.001) and large for disability improvement (31 trials, 4876 individuals, -0.77, -1.05 to -0.49; P < 0.001). In a univariate meta-regression model, sham needle location and/or depth could explain most or all heterogeneities for some conditions (e.g., shoulder pain, low back pain, osteoarthritis, myofascial pain, and fibromyalgia); however, the interactions between subgroups via these covariates were not significant (P < 0.05). Our review provided low-quality evidence that real acupuncture has a moderate effect (approximate 12-point reduction on the 100-mm visual analogue scale) on musculoskeletal pain. SA type did not appear to be related to the estimated effect of real acupuncture.

Traditional Chinese medicine for neck pain and low back pain: a systematic review and meta-analysis.

BACKGROUND: Neck pain (NP) and low back pain (LBP) are common symptoms bothering people in daily life. Traditional Chinese medicine (TCM) has been used to treat various symptoms and diseases in China and has been demonstrated to be effective. The objective of the present study was to review and analyze the existing data about pain and disability in TCM treatments for NP and LBP. METHODS: Studies were identified by a comprehensive search of databases, such as MEDLINE, EMBASE, and Cochrane Library, up to September 1, 2013. A meta-analysis was performed to evaluate the efficacy and safety of TCM in managing NP and LBP. RESULTS: Seventy five randomized controlled trials (n = 11077) were included. Almost all of the studies investigated individuals experiencing chronic NP (CNP) or chronic LBP (CLBP). We found moderate evidence that acupuncture was more effective than sham-acupuncture in reducing pain immediately post-treatment for CNP (visual analogue scale (VAS) 10 cm, mean difference (MD) = -0.58 (-0.94, -0.22), 95% confidence interval, p = 0.01), CLBP (standardized mean difference = -0.47 (-0.77, -0.17), p = 0.003), and acute LBP (VAS 10 cm, MD = -0.99 (-1.24, -0.73), p< 0.001). Cupping could be more effective than waitlist in VAS (100 mm) (MD = -19.10 (-27.61, -10.58), p < 0. 001) for CNP or medications (e.g. NSAID) for CLBP (MD = -5.4 (-8.9, -0.19), p = 0.003). No serious or life-threatening adverse effects were found. CONCLUSIONS: Acupuncture, acupressure, and cupping could be efficacious in treating the pain and disability associated with CNP or CLBP in the immediate term. Gua sha, tai chi, qigong, and Chinese manipulation showed fair effects, but we were unable to draw any definite conclusions, and further research is still needed. The efficacy of tuina and moxibustion is unknown because no direct evidence was obtained. These TCM modalities are relatively safe.