Salmon Calcitonin Attenuates Degenerative Changes in Cartilage and Subchondral Bone in Lumbar Facet Joint in an Experimental Rat Model

Enhancing Clinical Insights: New Radiographic Grading for Lumbar Facet Joint Degeneration, A Reliability Study

Background

Lumbar facet joint diseases can often lead to reduced work efficiency and increased medical costs. As a primary imaging tool in orthopedics, X-rays offer numerous advantages. However, there is no consensus on the classification of lumbar facet joints based on X-ray imaging.

Methods

This study was conducted for 356 patients between November 2017 and September 2023. A senior radiologist and a senior orthopedic surgeon discussed and established a grading system for lumbar facet joints based on both X-ray and MRI findings. Two double-blind attending spinal surgeons were asked to evaluate and grade the included cases. The intra-rater reliability and inter-rater reliability were evaluated by assessing the weighted kappa (κw) coefficient.

Results

The level of inter-rater reliability of MRI for complete agreement was good for Doctor A (κw = 0.792) and Doctor B (κw = 0.869). The inter-rater reliability coefficient for grading lumbar facet joint degeneration based on the radiograph was as follows: for Doctor A (κw = 0.702, session 1; κw = 0.847, session 2) and Doctor B (κw = 0.714, session 1; κw = 0.828, session 2). Moreover, the level of intra-rater reliability based on X-ray for complete agreement was excellent for Doctor A (κw = 0.843) and Doctor B (κw = 0.836).

Conclusion

We propose a new grading system for lumbar facet joint degeneration based on X-rays, which serves as a supplement to the Weishaupt and Pathria classifications. This grading system aims to provide clinicians with a more comprehensive understanding of lumbar facet joint degeneration, allowing for the use of a broader range of diagnostic tools to evaluate facet joint degeneration from multiple perspectives. We believe that this grading system can be valuable in assessing potential anatomical changes related to the facet joint, thereby informing modifications to surgical techniques and procedural steps.

Calcitonin treatment for osteoarthritis and rheumatoid arthritis - a systematic review and meta-analysis of preclinical data

Purpose

The aim of this study was to investigate the efficacy of calcitonin (CT) in animal models of experimental osteoarthritis (OA) and rheumatoid arthritis (RA), as new stabilized CT formulations are currently being introduced.

Methods

A comprehensive and systemic literature search was conducted in PubMed/MEDLINE and Embase databases to identify articles with original data on CT treatment of preclinical OA and RA. Methodological quality was assessed using the Systematic Review Centre for Laboratory Animal Experimentation's risk of bias tool for animal intervention studies. To provide summary estimates of efficacy, a meta-analysis was conducted for outcomes reported in four or more studies, using a random-effects model. Subgroup analyses were employed to correct for study specifics.

Results

Twenty-six studies were ultimately evaluated and data from 16 studies could be analyzed in the meta-analysis, which included the following outcomes: bone mineral density, bone volume, levels of cross-linked C-telopeptide of type I collagen, histopathological arthritis score, and mechanical allodynia. For all considered outcome parameters, CT-treated groups were significantly superior to control groups (P = 0.002; P = 0.01; P < 0.00001; P < 0.00001; P = 0.04). For most outcomes, effect sizes were significantly greater in OA than in RA (P ≤ 0.025). High in-between study heterogeneity was detected.

Conclusion

There is preclinical evidence for an antioxidant, anti-inflammatory, antinociceptive, cartilage- and bone-protective effect of CT in RA and OA. Given these effects, CT presents a promising agent for the treatment of both diseases, although the potential seems to be greater in OA.

Low back pain and osteoarthritis pain: a perspective of estrogen

Low back pain (LBP) is the world's leading cause of disability and is increasing in prevalence more rapidly than any other pain condition. Intervertebral disc (IVD) degeneration and facet joint osteoarthritis (FJOA) are two common causes of LBP, and both occur more frequently in elderly women than in other populations. Moreover, osteoarthritis (OA) and OA pain, regardless of the joint, are experienced by up to twice as many women as men, and this difference is amplified during menopause. Changes in estrogen may be an important contributor to these pain states. Receptors for estrogen have been found within IVD tissue and nearby joints, highlighting the potential roles of estrogen within and surrounding the IVDs and joints. In addition, estrogen supplementation has been shown to be effective at ameliorating IVD degeneration and OA progression, indicating its potential use as a therapeutic agent for people with LBP and OA pain. This review comprehensively examines the relationship between estrogen and these pain conditions by summarizing recent preclinical and clinical findings. The potential molecular mechanisms by which estrogen may relieve LBP associated with IVD degeneration and FJOA and OA pain are discussed.

Parathyroid Hormone (1-34) Attenuates Cartilage Degradation and Preserves Subchondral Bone Micro-architecture in Rats with Patella Baja-Induced-Patellofemoral Joint Osteoarthritis

Several studies have revealed that PTH1-34 may possess the potential for treating osteoarthritis (OA) and osteoporosis. However, no study has yet determined whether PTH1-34 can be used for the treatment of patella baja-induced patellofemoral joint OA (PFJOA). Thus, this study sought to assess the efficacy of PTH1-34 for the treatment of PFJOA in a rat model. Patella baja was induced in 3-month-old female Sprague-Dawley (SD) rats by patellar ligament shortening (PLS), after which the rats were randomly divided into three groups (n = 12): Sham, PLS, and PTH group (PTH + PLS, PTH1-34, 30 µg/kg/d, 5 days per week for 10 weeks). Thereafter, radiographic imaging, macroscopic and microscopic analyses, immunohistochemistry, and microcomputed tomography (CT) analysis were performed. The appearance of PLS-induced PFJOA promoted obvious changes in the patellar position and structure in the PLS group, which were characterized by cartilage degeneration, subchondral bone microstructure deterioration, patella baja, and increasing patella length. However, these negative characteristics were markedly ameliorated by PTH1-34, which not only inhibited cartilage catabolism by decreasing MMP-13 and ADAMTS-4 but also enhanced anabolism by increasing Col-II and Aggrecan. Furthermore, the micro-CT results showed a marked improvement in subchondral bone microarchitecture. The findings presented herein demonstrated that early treatment with PTH1-34 could improve cartilage metabolism and subchondral bone health in this PFJOA model.

Hsp22 Inhibits Oxidative Stress-Induced Endplate Chondrocyte Apoptosis by Regulating Mitochondrial Pathway

Background: Facet joint degeneration (FJD), which is also called facet joint syndrome (FJS), has become one of the most commonly seen etiological factors for lumbago. Cartilage lesion triggered by lumbar facet joint (LFJ) degeneration might be related to mitochondrial impairment, but the its underlying mechanism remains unclear. Materials and methods: The endplate chondrocytes were induced by hydrogen peroxide (H2O2) to mimic the pathological conditions of oxidative stress. Enzyme linked immunosorbent assay (ELISA) were used for the evaluation of reactive oxygen species (ROS). Adenosine-triphosphate (ATP) level was assessed using ATP detection, along with the detection the expression of cytochrome C in mitochondria (mito-cyt c) and in cell cytoplasm (cyto-cyt c) and cleaved caspase 3 by Western blot analysis. TUNEL assay was conducted for the measurement of cell apoptosis in endplate chondrocytes. Reverse transcription-polymerase chain reaction (RT-qPCR) was used to verify the expression of heat shock protein 22 (HSP22) and the transfection efficiency of HSP22 interference plasmid. Results: It was found that H2O2 promoted the mitochondrial dysfunction, ROS generation and cell apoptosis in endplate chondrocytes. Moreover, HSP22 was down-regulated in H2O2-induced endplate chondrocytes, and interference of HSP22 decreased the ROS production, increased the ATP level and promoted the cell apoptosis, resulting in the enhanced impairment of endplate chondrocytes. Additionally, mitochondrial ROS inhibitor (Mito-TEMPO) ameliorated the injury effects of HSP22 silencing in the H2O2-induced endplate chondrocytes. Conclusion: In conclusion, HSP22 inhibits oxidative stress-induced endplate chondrocyte apoptosis by regulating mitochondrial pathway, possibly providing novel guidance direction for the treatment of LFJ degeneration.

In vitro and in vivo effectiveness of a novel injectable calcitonin-loaded collagen/ceramic bone substitute

This study aimed to evaluate the effectiveness of a novel calcitonin-loaded calcium phosphate composite bone cement in vitro and in vivo. The novel composite bone cements were composed of NuROs injectable bone graft substitute, type I collagen, and/or salmon calcitonin. The setting time, porosity, wettability, compressive strength, compressive modulus, and crystallographic structures of cement specimens were determined. Degradation rate, calcitonin release rate, and osteoinductivity were assessed in vitro. In addition, osteogenic effect was examined in a rabbit model of femoral defect. The results revealed that addition of collagen/calcitonin did not substantially alter physical properties and degradation rate of bone cement specimens. Calcitonin was released into culture medium in a two-phase manner. Osteogenic effect of conditioned medium derived from calcitonin containing bone cement was observed. Finally, de novo bone growth and bone mineralization across the bone defect area were observed in rabbits after implantation of composite bone cement specimens. In conclusion, this novel calcitonin-loaded composite calcium phosphate bone cement exhibits biocompatibility, bioresorbability, osteoinductivity, and osteoconductivity, which may be suitable for clinical use.

Parathyroid hormone (1-34) ameliorates cartilage degeneration and subchondral bone deterioration in collagenase-induced osteoarthritis model in mice

Aims

Parathyroid hormone (PTH) (1-34) exhibits potential in preventing degeneration in both cartilage and subchondral bone in osteoarthritis (OA) development. We assessed the effects of PTH (1-34) at different concentrations on bone and cartilage metabolism in a collagenase-induced mouse model of OA and examined whether PTH (1-34) affects the JAK2/STAT3 signalling pathway in this process.

Methods

Collagenase-induced OA was established in C57Bl/6 mice. Therapy with PTH (1-34) (10 μg/kg/day or 40 μg/kg/day) was initiated immediately after surgery and continued for six weeks. Cartilage pathology was evaluated by gross visual, histology, and immunohistochemical assessments. Cell apoptosis was analyzed by TUNEL staining. Microcomputed tomography (micro-CT) was used to evaluate the bone mass and the microarchitecture in subchondral bone.

Results

Enhanced matrix catabolism, increased apoptosis of chondrocytes in cartilage, and overexpressed JAK2/STAT3 and p-JAK2/p-STAT3 were observed in cartilage in this model. All of these changes were prevented by PTH (1-34) treatment, with no significant difference between the low-dose and high-dose groups. Micro-CT analysis indicated that bone mineral density (BMD), bone volume/trabecular volume (BV/TV), and trabecular thickness (Tb.Th) levels were significantly lower in the OA group than those in the Sham, PTH 10 μg, and PTH 40 μg groups, but these parameters were significantly higher in the PTH 40 μg group than in the PTH 10 μg group.

Conclusion

Intermittent administration of PTH (1-34) exhibits protective effects on both cartilage and subchondral bone in a dose-dependent manner on the latter in a collagenase-induced OA mouse model, which may be involved in regulating the JAK2/STAT3 signalling pathway.

Cite this article: Bone Joint Res 2020;9(10):675–688.

Image-based analysis of trabecular bone in osteoporotic rabbits: correlation of morphological features and bone mineral density profile

OBJECTIVE

To analyse a set of morphological features from digital radiographs (RX) and bone mineral density (BMD) values estimated from quantitative computerized tomography scans (QCT scans) of the knee joint of an osteoporotic rabbits, and to determine the relationship and correlation of these variables to be considered as an alternative diagnosis method.

METHODS

The knee joint of rabbits (N = 9 ovariectomized and injected with of methylprednisolone sodium succinate (OVX + MPSS) and 3 sham operated healthy controls) were subjected to radiographic examination before the beginning of the study and after 6 weeks; after sacrifice, they were immediately scanned with a 64-channel CT. A set of morphological features was extracted from RX images and then subjected to Principal Component Analysis (PCA); BMD-values were calculated at different depths from the articular surface of the femur and the tibia. The selected morphological variables and the BMD values were correlated in order to determine useful information in medical diagnostics.

RESULTS

Ten morphological variables explained 80.39% of the total variability, but only some of them demonstrated significant differences between baseline and OVX + SSMP states and between OVX + SSMP and control. Spearman analysis showed higher positive and negative correlation of these parameters among them (r = 0.67, 0.81, 0.83 and 1); and a moderate correlation with the BMD values (r = 0.50, 0.52, 0.52 and 0.55) during the progression of osteoporosis (OP).

CONCLUSION

The Spearman's rank test supported the overall significant correlation between both, the morphological features and BMD values, making them as a reliable alternative option to the diagnosis of osteoporosis.

Protective Effect of Alendronate on Lumbar Facet Degeneration in Ovariectomized Rats

Background

Facet joint degeneration (FJD) is a potential source of lower back pain, and estrogen deficiency can accelerate FJD. The present study aimed to investigate the effects of alendronate (ALN) on FJD induced by ovariectomy (OVX) in rats.

Material/Methods

Thirty female Sprague-Dawley rats underwent either bilateral OVX (n=20) or sham surgery (n=10). The OVX rats subsequently received either subcutaneous ALN (70 μg/kg/week) or vehicle for 12 weeks. Subchondral bone mass and microarchitecture were evaluated by micro-computed tomography. Cartilage degradation was evaluated by toluidine blue staining and histological scoring.

Results

Compared with the Sham group, the OVX group had significantly decreased bone mineral density, bone volume/trabecular volume, and trabecular thickness, significantly increased trabecular separation in subchondral bone, and significantly higher histological score for cartilage degeneration, particularly loss of cartilage thickness. ALN treatment significantly reversed the changes in subchondral bone, preserved cartilage thickness, and reduced the histological score. Immunohistochemical analyses showed significantly decreased expression of ADAMTS-4, MMP-13, and caspase-3 in the OVX+ALN group compared with the OVX group.

Conclusions

Treatment with ALN suppressed bone loss, subchondral bone architecture deterioration, and cartilage degeneration in OVX rats, which can be explained by roles of ALN in preservation of subchondral bone mass and microarchitecture, and counteraction of catabolism and chondrocyte apoptosis in cartilage.

Effects of Salmon Calcitonin on the Concentrations of Monoamines in Periaqueductal Gray in Formalin Test

Background:

The receptors of salmon calcitonin, located on certain areas of the brain such as the periaqueductal gray matter, are responsible for pain modulation.

Aims:

The effects of intracerebroventricular injection of salmon calcitonin on the behavioral response to pain and on the levels of monoamines in the periaqueductal gray were explored using a biphasic animal model of pain.

Study Design:

Animal experiment.

Methods:

A total of 45 male rats were divided into four groups (n=6). Salmon calcitonin was injected into the lateral ventricle of the brain (1.5 nmol, with a volume of 5 μL). After 20 min, 2.5% formalin was subcutaneously injected into the right leg claw, and pain behavior was recorded on a numerical basis. At the time of the formalin test, the periaqueductal gray area was microdialized. High-performance liquid chromatography method was used to gauge the levels of monoamines and their metabolites.

Results:

Intracerebroventricular injections of salmon calcitonin resulted in pain reduction in the formalin test (p<0.05). The dialysate concentrations of serotonin, dopamine, norepinephrine, 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic, and 4-hydroxy-3-methoxyphenylglycol increased in the periaqueductal gray area in different phases of the formalin pain test (p<0.05).

Conclusion:

Salmon calcitonin reduced pain by increasing the concentrations of monoamines and the metabolites derived from them in the periaqueductal gray area.

A Novel Rat Model of Patellofemoral Osteoarthritis Due to Patella Baja, or Low-Lying Patella

Background

Patella baja, or patella infera, consists of a low-lying patella that results in a limited range of motion, joint pain, and crepitations. Patellofemoral joint osteoarthritis (PFJOA) is a subtype OA of the knee. This study aimed to develop a reproducible and reliable rat model of PFJOA.

Material/Methods

Three-month-old female Sprague-Dawley rats (n=24) included a baseline group (n=8) that were euthanized at the beginning of the study. The sham group (n=8), and the patella ligament shortening (PLS) group (n=8) were euthanized and evaluated at ten weeks. The PLS model group (n=8) underwent insertion of a Kirschner wire under the patella tendon to induce patella baja. At ten weeks, the sham group and the PLS group were compared using X-ray imaging, macroscopic appearance, histology, immunohistochemistry, TUNEL staining for apoptosis, and micro-computed tomography (micro-CT). The patella height was determined using the modified Insall-Salvati (MIS) ratio.

Results

The establishment of the rat model of patella baja in the PLS group at ten weeks was confirmed by X-ray. In the PLS group, patella volume, sagittal length, and cross-sectional area were significantly increased compared with the sham group. The PFJ showed typical lesions of OA, confirmed macroscopically and histologically. Compared with the sham group, in the rat model of PFJOA, there was increased cell apoptosis, and immunohistochemistry showed increased expression of biomarkers of osteoarthritis, compared with the sham group.

Conclusions

A rat model of PFJOA was developed that was confirmed by changes in cartilage and subchondral bone.