Axial rotation and pain are associated with facet joint osteoarthritis in Adolescent Idiopathic Scoliosis

The TLR-M-CSF axis is implicated in increased bone turnover and curve progression in adolescent idiopathic scoliosis

BACKGROUND

Facet joint osteoarthritis (OA) is prevalent in patients with adolescent idiopathic scoliosis (AIS). The most pronounced OA presents above and below the curve's apex where the intervertebral rotation is the greatest. This indicates that facet joint OA is implicated and potentially contributes to AIS progression. OA impacts both cartilage and bone and we have previously demonstrated an association between lower bone quality and more severe OA in AIS facet joints. This study aimed to further investigate the molecular mechanisms underlying cartilage-bone crosstalk in the facet joints of patients with AIS.

METHODS

Unbiased deep RNA sequencing was performed to compare gene expression in facet joint chondrocytes of age-matched AIS patients and non-scoliotic individuals. Differentially expressed genes of interest were validated through qPCR and ELISA in a larger sample cohort. Key regulatory pathways involved in cartilage-bone crosstalk were identified through bioinformatic analysis. Functional studies were conducted by treating chondrocytes with TLR2 and TLR4 agonists, collecting conditioned media, and administering it to an in vitro osteoclastogenesis model. The expression of M-CSF, a key regulatory factor influencing osteoclast proliferation, was measured in individual facet joint cartilage samples at different spinal levels and correlated with cartilage morphological grade and 3D structural parameters extracted from spine reconstruction.

RESULTS

One thousand four hundred twenty six upregulated genes were detected, and gene ontology analysis revealed a significant enrichment of the TLR pathway, and bone-regulating biological processes in AIS chondrocytes. TLR activation of AIS chondrocytes induced expression of bone-regulating factors, including M-CSF, a key regulator of osteoclast proliferation. Furthermore, secreted factors from AIS chondrocytes enhanced osteoclast proliferation and maturation, with a stronger effect observed following TLR pre-activation. Clinically, M-CSF expression was found to correlate strongly with increased OA severity and a greater degree of intervertebral axial rotation.

CONCLUSIONS

Together, our findings suggest that the TLR-M-CSF axis is implicated in osteoclastogenesis, resulting in increased bone turnover and may contribute to curve progression in AIS patients.

Influence of coronal lumbar Cobb angle and surgical level on short-segment lumbar surgery outcomes in degenerative scoliosis

PURPOSE

This study investigates the relationship between surgical levels and coronal deformity to identify risk factors for failing to achieve a minimal clinically important difference (MCID) in the Oswestry Disability Index (ODI) following short-segment isolated decompression or fusion surgery in patients with degenerative scoliosis (DS) and concurrent lumbar canal stenosis (LCS), without severe sagittal deformity malalignment.

METHODS

Patients with degenerative scoliosis who underwent 1- or 2-level lumbar isolated decompression or fusion surgery were included. Surgical level was labeled as "Cobb-related" when decompression or surgical levels spanned or were between end vertebrae, and "outside" when the operative levels did not include the end vertebrae. Logistic regression analysis was conducted to assess the factor associated with MCID achievement in ODI at 1 year postoperatively.

RESULTS

A total of 129 DS patients with LCS and preoperative ODI > 30 were included. At 1-year follow-up, 91 patients (70.5%) achieved MCID in ODI. No significant differences were found in demographics or overall spinal alignment between patients who did and did not achieve MCID. Logistic regression analysis revealed that Cobb-related decompression was independently associated with decreased odds of achieving MCID in ODI (adjusted Odds Ratio 0.18, 95% CI 0.42-0.79, P = 0.025).

CONCLUSION

In patients with mild to moderate coronal deformity and minimal sagittal deformity, decompression alone at or across end vertebrae significantly lowers the likelihood of achieving the MCID in ODI compared to fusion surgery, with an 84% reduction in odds. No significant difference in MCID achievement was observed between decompression and fusion surgeries outside the Cobb angle.

Relationship between insertions of the tibialis anterior and peroneus longus and first tarsometatarsal joint degeneration

BACKGROUND

The purpose of this study was to clarify the relationships of the tibialis anterior tendon (TAT) and peroneus longus tendon (PLT) with articular cartilage degeneration on the medial cuneiform and first metatarsal.

METHODS

We examined 100 feet from 50 Japanese cadavers. The TAT was classified into 4 types based on attachment site area and number of fiber bundles: Type I, two fiber bundles with equal (within 20%) attachment site areas on the first metatarsal and medial cuneiform; Type II, with two fiber bundles and a larger (>20%) attachment site area on the medial cuneiform than on the first metatarsal; Type III, with two fiber bundles and a larger (>20%) attachment site area on the first metatarsal than on the medial cuneiform; and Type IV, with three fiber bundles. The PLT was classified into 2 types, following previous studies: Type I, insertion only to the base of the first metatarsal; Type II, insertion to the medial cuneiform and first metatarsal. The severity of articular cartilage degeneration was assessed in five stages using the International Cartilage Repair Society scale.

RESULTS

No significant difference in severity of articular cartilage degeneration was evident among types of TAT and PLT.

CONCLUSION

Our results suggested that anatomical variations in the TAT and PLT might not affect joint stability, indicating that strengthening of these muscles could potentially enhance stability regardless of morphological variations in the insertions.

Adolescent idiopathic scoliosis: treatment outcomes, quality of life and implications for practice

Adolescent idiopathic scoliosis (AIS) is the most common spinal disorder among children and adolescents, with most cases being diagnosed around puberty. While the majority of people with AIS do not undergo treatment, a small but significant number are treated, depending on the extent of their spinal curvature. Treatment typically involves bracing, which requires substantial adherence, and/or surgery, which is invasive and permanent. Furthermore, decisions about treatment often need to be made at a critical stage of the person's development. This article examines the evidence on AIS and its treatment, synthesising the current literature and drawing from the authors' empirical work to explore the clinical outcomes of bracing and surgery, as well as the longer-term effects on people's quality of life. Drawing from this evidence, the authors provide guidance for nurses and healthcare professionals who care for people with AIS.

Relationship between first tarsometatarsal ligament morphology and its continuity with the fibularis longus and first tarsometatarsal joint degeneration

This study explored the relationship between the morphological characteristics of the first tarsometatarsal ligaments and fibularis longus (FL) and the severity of articular cartilage degeneration in the first tarsometatarsal joint. Sixty legs from 30 cadavers were examined. The plantar, dorsal, and medial first tarsometatarsal ligaments were classified by fiber bundle number, and their morphological characteristics (fiber bundle length, width, thickness) were measured. The FL was categorized by its continuity with the plantar first tarsometatarsal ligament (PTML): Type A, connection with the PTML only on the first metatarsal; Type B, connection along the entire PTML; and Type C, no connection with the PTML. The severity of articular cartilage degeneration was assessed in four stages. No significant differences in cartilage degeneration among ligament types were found. Negative correlations were observed between the fiber bundle width and thickness of the PTML and the severity of cartilage degeneration. FL was classified as Type A in 68%, Type B in 27%, and Type C in 5% of feet. The fiber bundle thickness of the PTML in Type B was greater than in other types. Our findings suggest that smaller fiber bundle width and thickness in the PTML may be associated with severe cartilage degeneration. The FL had continuity with the PTML in 95% of feet and could enhance the mechanical strength of the PTML in Type B feet.

Three Stages on Magnetic Resonance Imaging of Lumbar Degenerative Spine

PURPOSES

To propose a new lumbar degenerative staging system using the current radiological classification system.

METHODS

A cross-sectional analysis of retrospective databases between January 2018 and December 2022 was performed. Total of 410 patients for Modic changes, paravertebral muscle fat infiltration, disc degeneration, articular process degeneration, vertebral endplate degeneration and other structures, and disc displacement, Spondylolisthesis, and stenosis, and grouped patients according to stage were assessed. Visual analog scale, Japanese Orthopaedic Association, and Oswestry Disability Index scores were used to assess low back pain strength, neurological function, and quality of life, respectively.

RESULTS

The lumbar degeneration staging system consists of 8 variables, which can be divided into 3 steps: early, middle and late, and the correlation between each variable is strong (P < 0.05). The later the staging, the worse the Japanese Orthopaedic Association, visual analog scale, and Oswestry Disability Index scores.

CONCLUSIONS

Patients with later stages have worse clinical scores. This staging system recommends a uniform classification to assess lumbar degeneration.

Relationship between joint structure of the first tarsometatarsal joint and its degeneration

This study aimed to elucidate the relationship between joint structures of the first tarsometatarsal and articular facet degeneration. A total of 100 feet from 50 cadavers were examined. The articular facets of the first metatarsal and medial cuneiform were categorized into four types based on the superior and inferior facets' separation, and the formation of the inferior lateral facet on the lateral plantar prominence: Type I, a single facet with no separation or inferior lateral facet; Type II-a, two facets with separation but no inferior lateral facet; Type II-b, two facets, no separation, but with an inferior lateral facet; Type III, three facets with separation and an inferior lateral facet. When both bone types matched, they were defined as Type I, Type II-a, Type II-b, and Type III joints, respectively; unmatched types were classified as Unpair joints. The severity of articular cartilage degeneration on both bones was assessed using a 5-point scale. The degeneration grade was compared among joint types. Type III joints exhibited significantly milder articular cartilage degeneration in medial cuneiform compared to Type II-a, II-b, Unpair joints. The formation of inferior lateral facet and separation of the superior and inferior facets might be crucial for the joint's stability.

Factors that influence in-brace derotation effects in patients with adolescent idiopathic scoliosis: a study based on EOS imaging system

OBJECTIVE

To investigate the effects of bracing on apical vertebral derotation and explore the factors that influence in-brace derotation effects in adolescent idiopathic scoliosis (AIS) patients. For patients with AIS, vertebral rotation causes cosmetic appearance abnormalities and acts as an indicator for curve progression. However, there have been few studies investigating the precise derotation effects of bracing for apical vertebra. The application of EOS imaging system enables quantitative evaluation of vertebral rotation in the axial plane in a standing position.

METHODS

There were 82 eligible patients enrolled in current study, who underwent EOS imaging evaluation before and immediately after bracing. The clinical demographic data (age, gender, Risser sign and menstrual status) were recorded. The correlation analyses between derotation effects and key parameters (age, pre-brace Cobb angle, thoracic kyphosis, lumbar lordosis, vertebral rotation, pelvis axial rotation and apical vertebral level) were performed. The in-brace derotation effects stratified by gender, Risser sign, apical vertebral level, menarche status, coronal balance and sagittal balance were also analyzed.

RESULTS

The rotation of apical vertebra was decreased from 8.8 ± 6.0 degrees before bracing to 3.8 ± 3.3 degrees immediately after bracing (p < 0.001), and the derotation rate was 49.2 ± 38.3%. The derotation degrees in brace was significantly correlated with major curve Cobb angle (r = 0.240, p = 0.030), minor curve Cobb angle (r = 0.256, p = 0.020) and total curve Cobb angle (r = 0.266, p = 0.016). Both the pre-brace apical vertebral rotation and apical vertebral level were significantly correlated with derotation effects in brace (p < 0.001). Patients with thoracic major curve showed worse derotation effects than those with lumbar major curve (p < 0.001). In addition, patients with coronal balance showed better in-brace derotation effects than those with coronal decompensation (p = 0.005).

CONCLUSIONS

A satisfactory apical vertebral derotation rate (approximately 50%) could be obtained immediately after bracing in AIS patients. Pre-brace Cobb angle of curve, pre-brace apical vertebral rotation, apical vertebral level and coronal balance exhibited close associations with in-brace derotation effects of apical vertebra.