Interleukin-6 and severity of COVID-19 patients in Hefei, China

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Twenty-four out of 75 patients developed into severe condition in the course of the infection.

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The prominent laboratory abnormalities of COVID patients were lymphopenia, elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH).

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Elevated interleukin 6 (IL-6) correlated with decrease of LYM%, CD4⁺ and CD8⁺ T cell counts, and increase of CRP, LDH and Procalcitonin (PCT) levels.

FRI0383 A RANDOMISED PLACEBO-CONTROLLED CLINICAL TRIAL OF CURCUMA LONGA EXTRACT FOR TREATING SYMPTOMS AND EFFUSION-SYNOVITIS OF KNEE OSTEOARTHRITIS (CURKOA TRIAL)

Background:

Pharmacological therapies are limited, associated with off-target effects, are frequently contraindicated, and only modestly effective for pain in osteoarthritis (OA). Effusion and synovitis are common in OA and are associated with symptomatic and structural progression of OA.Curcuma longa(Turmeric) extract has anti-inflammatory effects and is gaining popularity in the treatment of OA despite the lack of high-quality evidence.

Objectives:

The CurKOA trial aimed to determine the efficacy ofCurcuma longaextract for reducing knee symptoms and effusion-synovitis in patients with symptomatic knee OA and knee effusion-synovitis.

Methods:

In this randomised, double-blind, placebo-controlled trial, participants with significant knee pain (≥ 40 mm on a 100-mm visual analog scale [VAS]), symptomatic knee OA (by ACR criteria) and ultrasound defined effusion-synovitis were randomised to receiveCurcuma longaextract (80% aqueous based extract standardized to turmerosaccharides + 20% curcuminoids, 2 × 500 mg capsules/day) or identical placebo for 12 weeks. Knee MRI scans were obtained at baseline and 12 weeks. Coprimary outcomes were changes in knee pain assessed by VAS and change in knee effusion-synovitis volume assessed by MRI over 12 weeks.

Results:

Among 70 participants (36 receivedCurcuma longa, 34 received placebo, age 61.8±8.6 years, 56% female),Curcuma longasignificantly improved VAS knee pain compared to placebo (-9.11mm, 95% confidence interval [CI] [- 17.79 to -0.44]) over 12 weeks, equivalent to a standardised effect size of 0.50. There was no significant between group difference in change in effusion-synovitis volume (3.24 mL [-0.33, 6.82]). There were significantly greater reductions in WOMAC knee pain (-47.22mm [-81.22, -13.22]), WOMAC function (-112.26mm [-222.79 to -1.74]) and significantly more OARSI-OMERACT treatment responders (63% treatment vs. 38% placebo [Risk Ratio=1.64 (1.00 to 2.70)]) in theCurcuma longagroup compared to the placebo group. There was no significant between-group difference in lateral femoral cartilage T2 relaxation time (-0.38 ms [- 1.10 to 0.34]) assessed from compositional MRI. The incidence of adverse events was similar in theCurcuma longa(n=14 (39%)) and placebo (n=18 (53%)) groups over 12 weeks (P=0.24).

Conclusion:

An extract ofCurcuma longasignificantly improved knee pain in an inflammatory phenotype of knee OA patients over 12 weeks compared to placebo but had no effect on knee effusion-synovitis and cartilage composition assessed using MRI. The moderate effect size of the treatment supports the use ofCurcuma longaextract for the symptomatic management of knee OA.

Figure 1.

Disclosure of Interests:

None declared

OP0246 MIR-214-3P PROTECTS AGAINST OSTEOARTHRITIS BY DIRECTLY TARGETING NF-ĸB PATHWAY

Background:

Osteoarthritis (OA) is a degenerative disease associated with changes in the articular cartilage and bone, severely affecting patients’ mobility and quality of life. Multiple factors including mechanical stress, metabolic alteration and inflammatory mediators are involved in the complex pathogenesis of OA[1]. Interventions targeting these pathogenic factors may contribute to the treatment of OA. MiRNAs are single strand non-coding small RNAs, which are regulated in chondrogenesis and OA[2,3]. Recent studies demonstrated that miRNAs are involved in the regulation of NF-κB signaling pathway by different mechanisms[4]. These interactions suggest that NF-κB related miRNAs may be used as potential biomarkers and drug therapeutic targets in clinical treatment of OA. However, the relationship between miR-214-3p and NF-κB pathway remains poorly understood in OA.

Objectives:

This study aimed to test the expression and biological function of miR-214-3p in OA, and explore its mechanism in osteoarthritic chondrocytes.

Methods:

Articular primary chondrocytes were isolated from human cartilage samples, which were acquired from patients with end-stage knee OA at the time of total knee replacement surgery (n = 27), according to protocols approved by the Ethic Committee of Zhujiang Hospital. Real time PCR (RT-PCR) and in situ hybridization (ISH) were used to detect the expression of miR-214-3p in OA and non-OA cartilage tissues. Interference of miR-214-3p was conducted using inhibitor, while overexpression of miR-214-3p was performed with mimics. Metabolism of extracellular matrix was detected by RT-PCR, western blotting and immunofluorescence in vitro. Flow cytometry were conducted to determine cell apoptosis. A luciferase reporter assay, was used to evaluate the interaction between miR-214-3p and its downstream target. Human chondrocytes were cotransfected with miR-214-3p and the IKBKB-overexpressing plasmid to confirm the interaction between miR-214-3p and NF-ĸB pathway. For in vivo studies, experimental OA was induced in 12-week-old male C57BL/6J mice by destabilization of the medial meniscus (DMM) surgery with miR-214-3p agomir intra-articular (IA) injection (once weekly for 12 days) or by IA injection (once weekly for 12 days) of miR-214-3p antiagomir. Mice were sacrificed 10 weeks after the first IA injection, and subjected to histological analyses.

Results:

MiR-214-3p was significantly reduced in human OA cartilage. The decreased expression of miR-214-3p in the OA cartilage tissues was directly associated with excessive apoptosis and imbalance between anabolic and catabolic factors of ECM. Mechanistically, we determined that miR-214-3p directly targeted IKBKB/IKK-b and thereby suppressed the activation of NF-ĸB pathway. IKBKB overexpression attenuated the inhibitory effect of miR-214-3p on NF-ĸB pathway. Furthermore, inhibition of miR-214-3p in mice joints triggered spontaneous cartilage loss and OA development, while IA injection of miRNA-214-3p agomir alleviated OA in the DMM mouse model.

Conclusion:

Our results reveal an important role of miR-214-3p in OA progression. MiR-214-3p was down-regulated while IKBKB was upregulated in OA. MiR-214-3p inhibits the NF-kB signaling pathway and suppresses the progression of OA through targeting IKBKB. Thus, miR-214-3p maybe a therapeutic target for OA.

References:

[1]Glyn-Jones S, Palmer AJR, Agricola R, Price AJ, Vincent TL, Weinans H, Carr AJ:Osteoarthritis.The Lancet2015,386(9991):376-387.

[2]Nugent M:MicroRNAs: exploring new horizons in osteoarthritis.Osteoarthritis and cartilage2016,24(4):573-580.

[3]Vicente R, Noel D, Pers YM, Apparailly F, Jorgensen C:Deregulation and therapeutic potential of microRNAs in arthritic diseases.Nature reviews Rheumatology2016,12(4):211-220.

[4]Xu B, Li YY, Ma J, Pei FX:Roles of microRNA and signaling pathway in osteoarthritis pathogenesis.Journal of Zhejiang University Science B2016,17(3):200-208.

Disclosure of Interests:

None declared

Qualitative and quantitative measures of prefemoral and quadriceps fat pads are associated with incident radiographic osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

To determine if qualitative and quantitative measures of prefemoral fat pad (PFP) and quadriceps fat pad (QFP) are associated with incident radiographic osteoarthritis (iROA) over 4 years in the Osteoarthritis Initiative (OAI) study.

DESIGN

Participants in this nested case-control study were selected from the OAI study with knees that had Kellgren Lawrence grades (KLG) of 0 or 1 at baseline. Case knees were defined by iROA (KLG≥ 2) over 4 years. Control knees without iROA were matched 1:1 with case knees. Magnetic resonance images (MRIs) were read at P0 (time of onset of iROA), P-1 (1 year prior to P0) and baseline, and used to assess PFP (i.e., prefemoral hyperintensity alteration, patellofemoral hyperintensity alteration, maximum axial area) and QFP (i.e., hyperintensity alteration, mass effect, maximum axial area). Conditional logistic regression analyses were performed to study the associations between PFP/QFP measures and iROA, after adjustment for covariates.

RESULTS

354 case knees with iROA were matched to 354 control knees. 66.9% of the participants were female, with an average age of 60.1 years. PFP prefemoral hyperintensity alteration measured at three time points (OR [95%CI]: 1.46 [1.18-1.82], 1.50 [1.20-1.88], 1.52 [1.22-1.89] respectively), PFP maximum axial area (OR [95%CI]: 1.07 [1.01-1.14], 1.08 [1.01-1.15], 1.08 [1.02-1.15] respectively) and QFP hyperintensity alteration (OR [95%CI]: 1.59 [1.27-2.00], 1.44 [1.13-1.82], 1.38 [1.09-1.73] respectively) were significantly associated with iROA in multivariable conditional logistic analyses. QFP mass effect measured at BL and P-1 (OR [95%CI]: 1.42 [1.11-1.82], 1.33 [1.01-1.73] respectively) were significantly associated with iROA.

CONCLUSIONS

Qualitative and quantitative measures of PFP and QFP are associated with increased iROA over 4 years.

Propagation of temporal coherence gratings in dispersive medium with a chirper

In this paper, the propagation of Temporal Coherence Grating (TCG) pulse trains in a dispersive medium with a chirp is investigated for the first time. The two-time mutual coherence function of the TCG pulse trains propagating through extended dispersive medium specified by temporal ABCD matrix is derived and the evolution of their mean intensity and temporal degree of coherence (DOC) is explored. It is shown that the distribution of the mean intensity can be modulated freely by the number of grating lobes N, grating constant a, pulse duration T₀, power distributions vn, group-velocity dispersion coefficient β₂ and the medium chirper s. Upon dispersive-medium propagation, the single pulse splits into N+1 subpulses with the same or different peak intensities which depend on power distributions vn. What's more, during the propagation the pulse self-focusing occurs being the chirp-induced non-linear phenomenon. And the distribution of temporal DOC will degenerate into Gaussian form from initial periodic coherence distribution with increasing propagation distance z or adjusting incident pulse parameters and medium dispersion. The physical explanation and numerical illustrations relating to the pulse behavior are included.

The morphology of proximal tibiofibular joint (PTFJ) predicts incident radiographic osteoarthritis: data from Osteoarthritis Initiative

OBJECTIVE

To determine whether the morphology of proximal tibiofibular joint (PTFJ) is associated with increased risk of incident radiographic osteoarthritis (iROA) over 4 years in the OA Initiative (OAI) study.

METHODS

A nested matched case-control study design was used to select participants from OAI study. Case knees were defined as those with iROA. Control knees were matched one-to-one by sex, age and radiographic status with case knees. T2-weighted MR images were assessed at P0 (the visit when incident ROA was found on radiograph), P1 (1 year prior to P0) and at OAI baseline. The contacting area of PTFJ (S) and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ) and coronal plane (posterior stress-bolstering area, Sυ) were assessed, respectively.

RESULTS

354 case knees and 354 matched control knees were included, with a mean age of 60 and a mean body mass index (BMI) of 28 kg/m². Baseline PTFJ morphological parameters (S, Sτ and Sυ) were significantly associated with iROA over 4 years, and these associations remained unchanged after adjustment for BMI, number of knee bending activities, self-reported knee injury and surgery. S, Sτ and Sυ were also significantly associated with iROA at P1 and P0. In subgroup analysed, S, Sτ and Sυ were associated with risks of incident joint space narrowing in the medial, but not the lateral tibiofemoral compartment.

CONCLUSION

Greater contacting area, load-bearing area and posterior stress-bolstering area of PTFJ were associated with increased risks of iROA, largely in the medial tibiofemoral compartment.

[Impact of heterotopic ossification after single-level cervical disc replacement on adjacent segment]

Objective: To investigate the impact of heterotopic ossification (HO) after cervical disc replacement (CDR) on clinical outcome and radiological outcome of adjacent segment. Methods: The data of patients underwent single-level Prestige-LP CDR between January 2008 and March 2014 in West China Hospital with a minimum 36 months of follow-up were retrospectively analyzed in this study. The incidence of HO, whether it affected clinical outcome, and its impact on adjacent segment intervertebral disc height (IDH), range of motion (ROM) and adjacent segment degeneration were observed. The data were compared with independent sample t test between the two groups. Results: Ninety-two patients were included in this study, including 48 males and 44 females, the mean age was (44±8) years, and the mean follow-up was (62±23) months. At the final follow-up, 34 patients developed HO after CDR, but the incidence of Grade 4 HO was 7.6%. In both of the HO and non-HO groups, clinical outcomes at the final follow-up were all significantly improved when compared to those before the operation. And there was no significant differences in any clinical indexes between the HO and non-HO groups. The adjacent segment IDH before operation and at the final follow-up in the HO group and non-HO group were similar(t=0.596, 0.825 and t=0.877, 0.644, all P>0.05). The preoperative adjacent segment ROM of HO group was similar with that in non-HO group(t=0.056, 0.709, both P>0.05), but the adjacent segment ROM in HO group was higher than that in the non-HO group at the final follow-up (upper adjacent segment: 10.0°±2.0° vs 9.0°±1.3°; lower adjacent segment: 10.2°±1.9° vs 8.8°±1.3°, t=2.824, 4.022, both P<0.05). The incidence of adjacent segment degeneration of HO group was higher than that of non-HO group at the final follow-up(41.2% vs 19.0%, χ(2)=5.343, P<0.05). Conclusions: HO is a common phenomenon in the long-term follow-up after the CDR operation with Prestige LP prosthesis, but HO does not affect the improvement of clinical outcome. HO after CDR might be one of important risk factors accelerating adjacent segment degeneration.

Label-free superresolution effect of nonlinear reverse saturation absorption thin films through difference method

Label-free superresolution effect of nonlinear reverse saturation absorption (NRSA) thin films was investigated through difference method, where a subdiffraction-limit spot signal was constructed by intensity subtraction of two spots obtained under different laser intensities. By using annealed InSb films as the NRSA thin films, we experimentally obtained the subdiffraction-limit spot signal, and the optimal reduction ratio was approximately 52.5% of the original spot. Experimental results agreed well with theoretical simulations. The simulation results of a 9-point array sample showed the capability to achieve nonfluorescence superresolution imaging using the NRSA effect.

Hypofractionated stereotactic radiotherapy combined with chemotherapy or not in the management of recurrent malignant gliomas: A systematic review and meta-analysis

Hypofractionated stereotactic radiotherapy (HFSRT) is a common salvage treatment for recurrent malignant glioma (MG). However, it remains controversial whether the combination of HFSRT and chemotherapy could improve survival for patients with recurrent MG compared to HFSRT alone. The present systematic review and meta-analysis aims to investigate this question, and tries to determine to what extent the addition of chemotherapy to HFSRT affects survival. A systematic review was performed to analyse the survival for patients treated with HFSRT combined with chemotherapy or not. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were pooled with random effects; and standard mean difference (MD) with 95% CIs for OS were pooled using the same strategy. A total of 7 studies including 388 patients with recurrent MG were eligible for our study. The OS survival of patients receiving combination therapy ranged from 8.7 to 23 months, and the median OS of patients underwent HFSRT ranged from 3.9 to 12 months. The meta-analyses resulted in the pooled HR of 0.44 (95% CI 0.30-0.65, p < 0.0001) (Cochran Q statistic 4.70, P = 0.320, I² = 14.8%) and pooled standard MD of 0.80 months (95% CI 0.41-1.18, p < 0.001) (Cochran Q statistic 10.16, p = 0.71, I² = 50.8%). The present study suggests that HFSRT + chemotherapy confers a slight survival improvement for patients with recurrent MG as compared with sole HFSRT management. To draw a more solid conclusion, greater investigation is warranted.

Ambulatory activity interacts with common risk factors for osteoarthritis to modify increases in MRI-detected osteophytes

OBJECTIVE

To investigate the longitudinal association between objectively measured ambulatory activity (AA) and knee MRI-detected osteophytes (OPs), and to test whether this relationship was modified by common risk factors for OA including sex, obesity, disease severity and knee injury history.

METHODS

408 community-dwelling adults aged 51-81 years were assessed at baseline and 2.7 years. T1-weighted fat-suppressed MRI was used to evaluate knee OPs at both time points. AA was assessed at baseline by pedometers and categorized as: less active (≤7499 steps per day), moderately active (7500-9999 steps per day) and highly active (≥10,000 steps per day).

RESULTS

Statistically significant interactions were detected between knee OA risk factors and AA on increases in MRI-detected OPs (all P < 0.05). In stratified analyses, being moderately active, compared to being less active, was protective against an increase in MRI-detected OPs (score change of ≥1) in females (relative risk (RR) = 0.42, 95%CI, 0.25-0.70, P < 0.01), those who were obese (RR = 0.50, 95%CI, 0.30-0.83, P < 0.01), those with radiographic OA (ROA) (RR = 0.68, 95%CI, 0.47-0.97, P = 0.02) and those with a history of knee injury (RR = 0.27, 95%CI, 0.08-0.88, P = 0.02) in almost every knee compartment, after adjustment for confounders. No statistically significant associations were found in males, non-obese, non-ROA or non-injury groups.

CONCLUSIONS

Being moderately active is protective against an increase in MRI-detected OPs in females, those with ROA, those who are obese and those with a history of knee injury. These findings suggest that being moderately active is beneficial for individuals who are at higher risk of knee OA.

Patellar tendon enthesis abnormalities and their association with knee pain and structural abnormalities in older adults

OBJECTIVE

To describe associations between presence of patellar tendon enthesis (PTE) abnormalities and symptoms, structural abnormalities, and total knee replacement (TKR) in older adult cohort.

METHODS

PTE abnormalities (presence of abnormal bone signal and/or bone erosion), were measured on T2-weighted magnetic resonance (MR) images at baseline in 961 community-dwelling older adults. Knee pain and function limitation were assessed using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Bone marrow lesions (BMLs), cartilage volume and defects score, and infrapatellar fat pad (IPFP) area were measured using validated methods. Incidence of TKR was determined by data linkage.

RESULTS

Participants with abnormal PTE bone signal and/or erosion was 20%. Cross-sectionally, presence of PTE abnormalities was associated with greater pain intensity while going up and down stairs (β = 0.22 (95% confidence interval (CI); 0.03, 0.41)), greater risk of femoral BMLs (RR = 1.46 (1.12, 1.90)) and worse tibial cartilage defects score (RR = 1.70 (1.16, 2.47), and smaller IPFP area (β = -0.27 (-0.47, -0.06) cm²), after adjustment of confounders. Longitudinally, presence of baseline PTE abnormalities was associated with a deleterious increase in tibial BML size (RR = 1.52 (1.12, 2.05)) over 10.7 years but not symptoms, other structural changes, or TKR.

CONCLUSION

PTE abnormalities are common in older adults. Presence of cross-sectional but not longitudinal associations suggests they are commonly co-exist with other knee structural abnormalities but may not play a major role in symptom development or structural change, excepting tibial BMLs.

Validation of a predictive method for sunscreen formula evaluation using gene expression analysis in a Chinese reconstructed full-thickness skin model

OBJECTIVE

This study aimed to establish a predictive in vitro method for assessing the photoprotective properties of sunscreens using a reconstructed full-thickness skin model.

MATERIALS AND METHODS

A full-thickness skin model reconstructed with human fibroblasts and keratinocytes isolated from Chinese skin was exposed to daily UV radiation (DUVR). We examined the transcriptomic response, identifying genes for which expression was modulated by DUVR in a dose-dependent manner. We then validated the methodology for efficacy evaluation of different sunscreens formulas.

RESULTS

The reconstructed skin model was histologically consistent with human skin, and upon DUVR exposure, the constituent fibroblasts and keratinocytes exhibited transcriptomic alterations in pathways associated with oxidative stress, inflammation and extracellular matrix remodelling. When used to evaluate sunscreen protection on the model, the observed level of protection from UV-induced gene expression was consistent with the corresponding protection factors determined clinically and allowed for statistical ranking of sunscreen efficacy.

CONCLUSIONS

Within this study we show that quantification of gene modulation within the reconstructed skin model is a biologically relevant approach with sensitivity and predictability to evaluate photoprotection products.

Oxytocin in metabolic homeostasis: implications for obesity and diabetes management

Oxytocin was once understood solely as a neuropeptide with a central role in social bonding, reproduction, parturition, lactation and appetite regulation. Recent evidence indicates that oxytocin enhances glucose uptake and lipid utilization in adipose tissue and skeletal muscle, suggesting that dysfunction of the oxytocin system could underlie the pathogenesis of insulin resistance and dyslipidaemia. Murine studies revealed that deficiencies in oxytocin signalling and oxytocin receptor expression lead to obesity despite normal food intake, motor activity and increased leptin levels. In addition, plasma oxytocin concentration is notably lower in obese individuals with diabetes, which may suggest an involvement of the oxytocin system in the pathogenesis of cardiometabolic disease. More recently, small scale studies demonstrated that intranasal administration of oxytocin was associated with significant weight loss as well as improvements in insulin sensitivity and pancreatic β-cell responsivity in human subjects. The multi-pronged effects of oxytocin signalling on improving peripheral insulin sensitivity, pancreatic function and lipid homeostasis strongly suggest a role for this system as a therapeutic target in obesity and diabetes management. The complexity of obesity aetiology and the pathogenesis of obesity-related metabolic complications underscore the need for a systems approach to better understand the role of oxytocin in metabolic function.

Associations between serum S100A8/S100A9 and knee symptoms, joint structures and cartilage enzymes in patients with knee osteoarthritis

OBJECTIVE

Animal studies suggest that S100A8/S100A9 may be involved in the pathogenesis of osteoarthritis (OA); however, there has been no clinical study examining the associations between serum S100A8/S100A9 and knee symptoms, joint structures and cartilage degradation enzymes in knee OA patients so far. Therefore, this study was designed to investigate the cross-sectional associations between serum levels of S100A8/S100A9 and the outcomes in patients with knee OA.

DESIGN

A total of 141 subjects with clinical knee OA were included. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was used to assess joint symptoms. Magnetic resonance imaging (MRI) was used to measure knee structural abnormalities including cartilage defects. Knee radiography was used to assess joint space narrowing (JSN), osteophytes and the radiographic severity of OA. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of S100A8/S100A9, matrix metalloproteinase (MMP)-3, MMP10 and MMP13.

RESULTS

In multivariable analyses, serum S100A8/S100A9 were positively associated with total WOMAC score (β: 0.111 per 10 ng/ml, P = 0.021), WOMAC weight-bearing pain (β: 0.015 per 10 ng/ml, P = 0.043) and WOMAC physical dysfunction (β: 0.091 per 10 ng/ml, P = 0.010), and had positive associations with total cartilage defects and cartilage defects at lateral femoral, lateral tibial and medial femoral sites (ORs: 1.006-1.008 per 10 ng/ml, all P < 0.05) and serum levels of MMP3 (β: 0.002 per 10 ng/ml, P = 0.032) in patients with clinical knee OA.

CONCLUSIONS

Serum levels of S100A8/S100A9 were positively associated with increased knee symptoms, cartilage defects and serum cartilage degradation enzymes in patients with knee OA, suggesting that S100A8/S100A9 may have a role to play in knee OA. Future longitudinal studies are required to confirm these findings.

A novel method for assessing proximal tibiofibular joint on MR images in patients with knee osteoarthritis

OBJECTIVES

To validate a method to measure the morphological parameters of the proximal tibiofibular joint (PTFJ) in patients with knee osteoarthritis (OA).

METHODS

408 participants were examined in this cross-sectional subject-based study. We calculated the fibular contacting area of PTFJ (S) and its projection areas onto the horizontal plane (load-bearing area, Sτ), the sagittal plane (lateral stress-bolstering area, Sφ) and the coronal plane (posterior stress-bolstering area, Sυ). Joint space narrowing (JSN) and osteophyte was measured using radiographs. Cartilage defects, bone marrow lesions (BMLs) and cartilage volume were evaluated using magnetic resonance imaging (MRI).

RESULTS

The average PTFJ fibular contacting area was 2.4 cm² (SD, ±0.7 cm²). Intra-observer and inter-observer reliabilities of measures of PTFJ morphological parameters were excellent (≥0.90). S, Sτ and Sφ were significantly associated with JSN in the medial tibiofemoral compartment (PR: 1.40, 95% CI 1.10-1.78; PR: 1.65, 95% CI 1.25-2.18 and PR: 0.53, 95% CI 0.29-0.97, respectively). There was a significantly positive association between S, Sτ and medial and/or femoral tibial cartilage defects. S, Sτ and Sυ were significantly and positively associated with medial and/or femoral tibial BMLs (PR: 1.36, 95% CI 1.12-1.64; PR: 1.47, 95% CI 1.17-1.83; and PR: 1.39, 95% CI 1.06-1.82, respectively) after adjustment. S and Sτ were significantly and negatively associated with medial tibial cartilage volume.

CONCLUSIONS

This novel method to assess the morphological parameters of PTFJ in MRI is reproducible. These parameters are associated with knee radiographic and MRI-based OA-related structural abnormalities, suggesting clinical construct validity. Its predictive validity needs to be examined in future longitudinal studies.