Association between age and knee structural change: a cross sectional MRI based study

Age-stratified analysis of temporomandibular joint osteoarthritis using cone-beam computed tomography

Purpose

This study aimed to evaluate age-stratified radiographic features in temporomandibular joint osteoarthritis using cone-beam computed tomography.

Materials and Methods

In total, 210 joints from 183 patients (144 females, 39 males, ranging from 12 to 88 years old with a mean age of 44.75±19.97 years) diagnosed with temporomandibular joint osteoarthritis were stratified by age. Mandibular condyle position and bony changes (flattening, erosion, osteophytes, subchondral sclerosis, and subchondral pseudocysts in both the condyle and articular eminence, thickening of the glenoid fossa, joint space narrowing, and joint loose bodies) were evaluated through cone-beam computed tomography. After adjusting for sex, the association between age groups and radiographic findings was analyzed using both a multiple regression model and a multinomial logistic regression model (α=0.05).

Results

The prevalence of joint space narrowing and protruded condyle position in the glenoid fossa significantly increased with age (P<0.05). The risks of bony changes, including osteophytes and subchondral pseudocysts in the condyle; flattening, erosion, osteophyte, and subchondral sclerosis in the articular eminence; joint loose bodies; and thickening of the glenoid fossa, also significantly rose with increasing age (P<0.05). The number of radiographic findings increased with age; in particular, the increase was more pronounced in the temporal bone than in the mandibular condyle (P<0.05).

Conclusion

Increasing age was associated with a higher frequency and greater diversity of bony changes in the temporal bone, as well as a protruded condyle position in the glenoid fossa, resulting in noticeable joint space narrowing in temporomandibular joint osteoarthritis.

Prognostic factors associated with changes in knee pain outcomes, identified from initial primary care consultation data. A systematic literature review

BACKGROUND

Data collected during initial primary care consultations could be a source of baseline prognostic factors associated with changes in outcome measures for patients with knee pain.

OBJECTIVES

To identify, appraise and synthesize studies investigating prognostic factors associated with changes in outcome for people presenting with knee pain in primary care.

METHODS

EMBASE, CINAHL, AMED, MEDLINE and MedRxiv electronic databases were searched from inception to March 2021 and repeated in August 2022. Prospective cohort studies of adult participants with musculoskeletal knee pain assessing the association between putative prognostic factors and outcomes in primary care were included. The Quality in Prognostic Studies (QUIPS) tool and The Modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework, specific to prognostic reviews were used to appraise and synthesize the evidence respectively.

RESULTS

Eight studies were included. Eight knee pain outcomes were identified. Methodological and statistical heterogeneity resulted in qualitative analysis. All evidence was judged to be of low to very low quality. Bilateral knee pain (multivariable odds ratio (OR) range 2.60-2.74; 95%CI range 0.90-8.10, p value = 0.09) and a lower educational level (multivariable (OR) range 1.74-5.6; 95%CI range 1.16-16.20, p value = <0.001) were synonymously associated with persisting knee pain at 12-month follow up. A total of 37 univariable and 63 multivariable prognostic factors were statistically associated with outcomes (p ≤ 0.05) in single studies.

CONCLUSIONS

There was consensus from two independent studies that bilateral knee pain and lower educational level were associated with persistent knee pain. Many baseline factors were associated with outcome in individual studies but not consistently between studies. The current understanding, accuracy and reliability of the prognostic value of initial primary care consultation data for knee pain outcomes are limited. This review will provide an essential guide for candidate variable selection in future primary care prognostic confirmatory studies.Key messagesBilateral knee pain and lower educational level were associated with persistent knee pain.Many baseline factors were associated with outcome in individual studies but not consistently between studies.The current understanding, accuracy and reliability of the prognostic value of initial primary care consultation data for knee pain outcomes are limited.

Charting Aging Trajectories of Knee Cartilage Thickness for Early Osteoarthritis Risk Prediction: An MRI Study from the Osteoarthritis Initiative Cohort

Knee osteoarthritis (OA), a prevalent joint disease in the U.S., poses challenges in terms of predicting of its early progression. Although high-resolution knee magnetic resonance imaging (MRI) facilitates more precise OA diagnosis, the heterogeneous and multifactorial aspects of OA pathology remain significant obstacles for prognosis. MRI-based scoring systems, while standardizing OA assessment, are both time-consuming and labor-intensive. Current AI technologies facilitate knee OA risk scoring and progression prediction, but these often focus on the symptomatic phase of OA, bypassing initial-stage OA prediction. Moreover, their reliance on complex algorithms can hinder clinical interpretation. To this end, we make this effort to construct a computationally efficient, easily-interpretable, and state-of-the-art approach aiding in the radiographic OA (rOA) auto-classification and prediction of the incidence and progression, by contrasting an individual's cartilage thickness with a similar demographic in the rOA-free cohort. To better visualize, we have developed the toolset for both prediction and local visualization. A movie demonstrating different subtypes of dynamic changes in local centile scores during rOA progression is available at https://tli3.github.io/KneeOA/. Specifically, we constructed age-BMI-dependent reference charts for knee OA cartilage thickness, based on MRI scans from 957 radiographic OA (rOA)-free individuals from the Osteoarthritis Initiative cohort. Then we extracted local and global centiles by contrasting an individual's cartilage thickness to the rOA-free cohort with a similar age and BMI. Using traditional boosting approaches with our centile-based features, we obtain rOA classification of KLG ≤ 1 versus KLG = 2 (AUC = 0.95, F1 = 0.89), KLG ≤ 1 versus KLG ≥ 2 (AUC = 0.90, F1 = 0.82) and prediction of KLG2 progression (AUC = 0.98, F1 = 0.94), rOA incidence (KLG increasing from < 2 to ≥ 2; AUC = 0.81, F1 = 0.69) and rOA initial transition (KLG from 0 to 1; AUC = 0.64, F1 = 0.65) within a future 48-month period. Such performance in classifying KLG ≥ 2 matches that of deep learning methods in recent literature. Furthermore, its clinical interpretation suggests that cartilage changes, such as thickening in lateral femoral and anterior femoral regions and thinning in lateral tibial regions, may serve as indicators for prediction of rOA incidence and early progression. Meanwhile, cartilage thickening in the posterior medial and posterior lateral femoral regions, coupled with a reduction in the central medial femoral region, may signify initial phases of rOA transition.

Mid-term prognosis of the stromal vascular fraction for knee osteoarthritis: a minimum 5-year follow-up study

Background

The short-term safety and efficacy of stromal vascular fraction (SVF) in treating knee osteoarthritis (KOA) have been extensively studied but the mid-term and long-term prognoses remain unknown.

Methods

126 KOA patients were recruited and randomly assigned to SVF group and hyaluronic acid (HA) group (control group). The scores of visual analogue scale (VAS) and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) were assessed and compared between the two groups 1, 2, 3, and 5 years after treatment. The endpoint was defined as surgeries related to KOA or clinical scores exceeding the patient acceptable symptom state (PASS).

Results

The VAS and WOMAC scores in the SVF group were significantly better than those in the HA group during the 5-year follow-up after treatment. The average responsive time to SVF treatment (61.52 months) was significantly longer than HA treatment (30.37 months). The adjusted Cox proportional hazards model showed that bone marrow lesion (BML) severity, body mass index (BMI) and treatment were independent risk factors and that the use of SVF reduced the risk of clinical failure by 2.602 times. The cartilage volume was reduced in both the SVF and control groups at 5 years but reduced less in the SVF group.

Conclusions

Up to 5 years after SVF treatment, acceptable clinical state was present for approximately 60% of patients. BML severity and BMI were independent predictors of the prognosis.

Trial Registry: This study was retrospectively registered at Chinses Clinical Trial Registry with identifier ChiCTR2100052818 and was approved by ethics committee of the First Affiliated Hospital of Zhejiang Chinese Medical University, number 2013-X-063.

Associations between serum biomarkers of cartilage metabolism and serum hyaluronic acid, with risk factors, pain categories, and disease severity in knee osteoarthritis: a pilot study

BACKGROUND

Specific serum biomarkers of cartilage metabolism such as cartilage oligomeric matrix protein (sCOMP) and procollagen type II C-terminal propeptide (sPIICP) as well as hyaluronan (sHA), a biomarker of synovitis, have been implicated in the pathophysiology of knee osteoarthritis (OA). However, the associations of these biomarkers with the severity of the disease and OA risk factors, including age and obesity remain inconclusive. This analysis examines the associations between these serum biomarkers and the radiographic severity of OA and knee pain, as wells as obesity, the age and gender of the participants, and other OA risk factors.

METHODS

From 44 patients with early knee OA and 130 patients with late knee OA we analyzed the radiographic severity of the disease using the Kellgren and Lawrence (KL) grading system. Moreover, 38 overweight healthy individuals were used as a control group. Specific information was collected from all participants during their recruitment. The levels of the three serum biomarkers were quantified using commercially available ELISA kits. Serum biomarkers were analyzed for associations with the average KL scores and pain in both knees, as well as with specific OA risk factors.

RESULTS

The levels of sCOMP were elevated in patients with severe late OA and knee pain and correlated weakly with OA severity. A weakly correlation of sHA levels and OA severity OA was observed. We demonstrated that only sPIICP levels were markedly decreased in patients with late knee OA suggesting the alterations of cartilage metabolism in this arthritic disease. Moreover, we found that sPIICP has the strongest correlation with obesity and the severity of OA, as well as with the knee pain at rest and during walking regardless of the severity of the disease. ROC analysis showed that the area under the ROC curve (AUC) was 0.980 (95% CI: 0.945-0.995; p < 0.0001), suggesting high diagnostic accuracy of sPIICP. Interestingly, gender and age had also an effect on the levels of sPIICP.

CONCLUSION

This study revealed the potential of serum PIICP to be used as a biomarker to monitor the progression of knee OA, however, further studies are warranted to elucidate its clinical implication.

Fatty Acid-Binding Protein 4 (FABP4) Is Associated with Cartilage Thickness in End-Stage Knee Osteoarthritis

BACKGROUND

There is no single blood biomarker for the staging of knee osteoarthritis (KOA). The purpose of this study was to assess the relationship of obesity, serum biomarkers, the hip-knee-ankle angle (HKAA) with sonographic cartilage thickness.

METHODS

We conducted a cross-sectional study of n = 33 patients undergoing knee arthroplasty. Body mass index (BMI) was recorded, and patients were grouped based on BMI. Serum blood samples were collected, and the following biomarkers were measured using the ELISA technique (subgroup of n = 23): oxidized low-density lipoprotein (oxLDL), soluble receptor for advanced glycation end-products (sRAGE), fatty acid-binding protein 4 (FABP4), membrane-bound phospholipase A2 (PLA2G2A). The HKAA was analyzed on full-length limb standing x-ray images. Cartilage thickness was assessed on ultrasound images. Multivariable regression analysis was performed to account for confounding.

RESULTS

After adjusting for age, gender, and HKAA, obese patients had thicker medial femoral cartilage (β = 0.165, P = 0.041). Furthermore, lateral cartilage thickness was negatively correlated with FABP4 level after adjusting for of age, gender, BMI, and HKAA (β = -0.006, P = 0.001). Confirming previous studies, after adjustment, FABP4 level was associated with a higher BMI group (β = 42.99, P < 0.001). None of the other markers (oxLDL, PLA2G2A, and sRAGE) was associated with BMI or cartilage thickness.

DISCUSSION

Our results indicate that BMI has a weak, positive association with cartilage thickness in end-stage KOA patients. FABP4 levels were negatively associated with cartilage thickness. While our study is limited by a small sample size, these results further highlight the role of FABP4 as promising biomarkers of burden of disease in KOA.

Biological reconstruction of the joint: Concepts of articular cartilage regeneration and their scientific basis

Articular cartilage injuries are common. The diagnosis of these injuries is often delayed and may lead to early osteoarthritis. Treatment depends on many factors but mainly on the stage and size of the lesion. The anatomy of articular cartilage is complex, and it is an avascular, aneural, and alymphatic structure. Recently, more emphasis is laid on its anatomy and biomechanics to understand the regeneration process of articular cartilage.

Value of passive anterior tibial subluxation on axial MRI in identifying anterior cruciate ligament functional deficiency in patients with advanced anteromedial osteoarthritis of the knee: a case-control study

BACKGROUND

A functionally deficient anterior cruciate ligament (ACL) is considered one of the contraindications in unicompartmental knee arthroplasty (UKA). But there is still a lack of standardized and reproducible methods to assess ACL functional integrity in patients with advanced anteromedial osteoarthritis of the knee (AMOA). This study explores the value of passive anterior tibial subluxation (PATS) on axial MRI in evaluating ACL status in this population.

METHODS

Patients who met UKA indications between November 2017 and September 2020 were included and grouped into "intact" (ACLI) or "deficient" (ACLD) group according to their ACL status during surgery. All participants underwent MRI with a standardized protocol. The measurements of medial and lateral PATS were conducted on axial MRI, and the mean of them was calculated as global PATS. Then the reliability and diagnostic ability of PATS were determined.

RESULTS

A total of 85 patients (45 for ACLI group, 40 for ACLD group) were included after selection. The measurements of PATS showed excellent intra- and inter-observer reliabilities (with an intraclass correlation coefficient of at least 0.986). The global PATS of the ACLI group was significantly lower than that of the ACLD group (- 2.30 ± 1.96 vs. 1.03 ± 1.96 mm, P<0.0001). The diagnostic ability of global PATS was good (area under the curve = 0.897), and a threshold of 1.2 mm had a specificity of 100%, a sensitivity of 55%, and an accuracy of 78.82%.

CONCLUSION

An axial global PATS of 1.2 mm on MRI is greatly specific for identifying a functionally deficient ACL in patients with advanced AMOA.

Collagen fibres determine the crack morphology in articular cartilage

Cracks in articular cartilage compromise tissue integrity and mechanical properties and lead to chondral lesions if untreated. An understanding of the mechanics of cracked cartilage may help in the prevention of cartilage deterioration and the development of tissue-engineered substitutes. The degeneration of cartilage in the presence of cracks may depend on the ultrastructure and composition of the tissue, which changes with aging, disease and habitual loading. It is unknown if the structural and compositional differences between immature and mature cartilage affect the mechanics of cartilage cracks, possibly predisposing one to a greater risk of degeneration than the other. We used a fibre-reinforced poro-viscoelastic swelling material model that accounts for large deformations and tension-compression non-linearity, and the finite element method to investigate the role of cartilage structure and composition on crack morphology and tissue mechanics. We demonstrate that the crack morphology predicted by our theoretical model agrees well with the histo-morphometric images of young and mature cracked cartilages under indentation loading. We also determined that the crack morphology was primarily dependent on collagen fibre orientation which differs as a function of cartilage depth and tissue maturity. The arcade-like collagen fibre orientation, first discussed by Benninghoff in his classical 1925 paper, appears to be beneficial for slowing the progression of tissue cracks by 'sealing' the crack and partially preserving fluid pressure during loading. Preservation of the natural load distribution between solid and fluid constituents of cartilage may be a key factor in slowing or preventing the propagation of tissue cracks and associated tissue matrix damage. STATEMENT OF SIGNIFICANCE: Cracks in articular cartilage can be detrimental to joint health if not treated, but it is not clear how they propagate and lead to tissue degradation. We used an advanced numerical model to determine the role of cartilage structure and composition on crack morphology under loading. Based on the structure and composition found in immature and mature cartilages, our model successfully predicts the crack morphology in these cartilages and determines that collagen fibre as the major determinant of crack morphology. The arcade-like Benninghoff collagen fibre orientation appears to be crucial in 'sealing' the tissue crack and preserves normal fluid-solid load distribution in cartilage. Inclusion of the arcade-like fibre orientation in tissue-engineered construct may help improve its integration within the host tissue.

An exploratory study to investigate the association between age, physical activity, femoral trochlear cartilage thickness and biomarkers of tissue metabolism in adult males

Purpose

To investigate the association between age, physical activity, femoral trochlear cartilage thickness and biomarkers of tissue metabolism in a cross-sectional sample of adult males. This study utilizes several emerging biomarkers that have been associated with early joint degenerative changes; serum COMP (cartilage oligomeric matrix protein), HA (hyaluronan) and lubricin.

Methods

Eighty-one males (age: mean (range): 43(18–70) years; body mass index: 25.2 (21.0–30.6) kg/m²) volunteered. Resting serum COMP, HA and lubricin concentrations were determined via commercially available enzyme-linked immunosorbent assay (ELISA) and femoral trochlear cartilage thickness via supra-patellar ultrasound imaging. Physical activity levels were assessed using questionnaires. Statistical analyses were performed using correlation and regression analyses.

Results

Age was correlated with lateral trochlear cartilage thickness (r = − 0.372; p < 0.01) and serum COMP (r = 0.342; p < 0.01). 7-day physical activity was correlated with serum COMP (r = 0.357, p < 0.01), and 12-month physical activity with both lateral trochlear cartilage thickness (r = 0.340, p = 0.01) and serum HA (r = 0.296, p < 0.05). Regression analyses revealed that age significantly accounted for the variability in lateral cartilage thickness and serum COMP, following the adjustment for potential cofounders. However, the association between age and lateral trochlear cartilage thickness was not moderated by physical activity levels (all p > 0.05).

Conclusion

This study indicates that older age may be associated with thinner lateral trochlear cartilage and higher cartilage turnover. Being physically active may also be positive for lateral trochlear cartilage thickness. However, overall, both age and physical activity level only account for a small amount of the variability in cartilage thickness and serum biomarkers.

[Functional improvement and thickening of quadriceps muscle and femoral intercondylar cartilage after a single intra-articular injection of a new bionic cross-linked hyaluronic acid Flexotron Cross in the treatment of knee joint osteoarthritis]

OBJECTIVE

To evaluate an effectiveness of a single intra-articular injection of a new cross-linked hyaluronic acid by measuring thickness of the quadriceps muscle and femoral intercondylar cartilage in addition to subjective assessment.

MATERIAL AND METHODS

There were 49 patients with gonarthrosis (Kellgren-Lawrence grade II-III) who underwent a single intra-articular injection of Flexotron Cross into the knee joint with higher grade of arthrosis. The scores were assessed at baseline, after 1, 3 and 6 months using: 1) visual analogue scale (VAS) of pain syndrome, 2) Western Ontario and McMaster University Osteoarthritis Index (WOMAC), 3) Lequesne Index, 4) duration of standing on one leg, 5) thigh circumference, 6) thickness of quadriceps muscle and femoral intercondylar cartilage according to ultrasound data.

RESULTS

A 6-month follow-up comprised 46 patients. HA administration significantly improved all parameters (p <0.001). VAS and WOMAC pain scores were significantly improved after 1, 3 and 6 months (p <0.01). Thickness of the quadriceps muscle and femoral intercondylar cartilage was increased after 3 and 6 months (p <0.05). Lequesne Index, duration of standing on one leg and thigh circumference were also increased in 6 months after HA administration (p <0.01).

CONCLUSION

Flexotron Cross is effective subjectively and objectively for at least 6 months and safe for the treatment of gonarthrosis.

Dispersion of knee helical axes during walking in young and elderly healthy subjects

Knee joint rotation center displacement can be estimated in vivo through the analysis of helical axis (HAs) dispersion. HAs can be analyzed during walking, providing information on joint stability. The study aim was to describe knee HAs dispersion during walking in dominant and non-dominant legs of young and elderly healthy subjects. Twenty young (YG: age 23.3 ± 2.4 years) and twenty elderly (EG: age 69.3 ± 4.6 years) healthy subjects were asked to walk on a treadmill at a self-selected speed with reflective markers placed bilaterally on thighs and shanks to detect HAs dispersion and knee kinematics with an optoelectronic system. HAs dispersion was described during the following four phases of gait cycle: (1) flexion from 95% of the previous gait cycle to 10% of the subsequent gait cycle, (2) extension from 10% to 40%, (3) flexion from 40% to 75% and (4) extension from 75% to 95% of the gait cycle. Mean Distance (MD) and Mean Angle (MA) were used as HAs dispersion indexes during each gait phase. Participants showed greater MD and MA in sagittal and frontal planes during the first and second phases. EG revealed higher MD (p = 0.001) and MA (p < 0.001) during the first phase and higher MA (p = 0.001) during the fourth phase in both dominant and non-dominant legs on the sagittal plane. HAs dispersion could be related to the amount of forces acting on knee (first two phases) and knee degeneration (elderly). These results may be used as reference data in further studies on HAs dispersion in presence of knee pathologies or after knee surgery or rehabilitation.

Examining the Association of Knee Pain with Modifiable Cardiometabolic Risk Factors

OBJECTIVE

There is a well-established link between obesity and knee osteoarthritis, and recent research has implicated diabetes as a potential cause of cartilage degeneration. This study uses the National Health and Nutrition Examination Survey (NHANES) database to examine the association between knee pain and various metabolic factors.

METHODS

A retrospective cross-sectional study of the NHANES database from 1999 to 2004 was performed. The main outcome was any knee pain and bilateral knee pain. Main effects of interest were body mass index (BMI), and hemoglobin A1c (HbA1c). We additionally assessed various patient factors including age, race, poverty, gender and smoking status. Multivariable logistic regression models and interaction terms were analyzed.

RESULTS

Data on 12,900 patients was included. In the main adjusted analysis, the modifiable risk factors associated with any knee pain were: overweight (OR 0.91; 95% CI 0.85, 0.97), obesity (OR 1.54; 95% CI 1.42, 1.66), glycemic control (OR 1.20; 95% CI 1.03, 1.38), and current smokers (OR 1.15; 95% CI 1.05, 1.27), all p<0.05. These same factors remain significant for bilateral knee pain. Subgroup analysis showed patients under 65 years old have a 5% increase in risk of any knee pain as their body mass index increases, but patients 65 years and older have a 10% increase in risk.

CONCLUSION

This study confirms the association of knee pain with increased weight, glycemic control, current smoking and age. Most of these risk factors can be modified in patients with knee pain and should be discussed when providing conservative treatment options.

Identifying Morphological Indicators of Aging With Neural Networks on Large-Scale Whole-Body MRI

A wealth of information is contained in images obtained by whole-body magnetic resonance imaging (MRI). Studying the link between the imaged anatomy and properties known from outside sources has the potential to give new insights into the underlying factors that manifest themselves in individual human morphology. In this work we investigate the expression of age-related changes in the whole-body image. A large dataset of about 32,000 subjects scanned from neck to knee and aged 44-82 years from the UK Biobank study was used for a machine-based analysis. We trained a convolutional neural network based on the VGG16 architecture to predict the age of a given subject based on image data from these scans. In 10-fold cross-validation on 23,000 of these images the network reached a mean absolute error (MAE) of 2.49 years (R² = 0.83) and showed consistent performance on a separate test set of another 8,000 images. On a second test set of 100 images the network outperformed the averaged estimates given by three experienced radiologists, which reached an MAE of 5.58 years (R² = 0.08), by more than three years on average. In an attempt to explain these findings, we employ saliency analysis that opens up the image-based criteria used by the automated method to human interpretation. We aggregate the saliency into a single anatomical visualization which clearly highlights structures in the aortic arch and knee as primary indicators of age.

Clinical characteristics associated with depression or anxiety among patients presenting for knee surgery

BACKGROUND

Preoperative depression and anxiety in patients undergoing surgery have been shown to be associated with increased postoperative complications, decreased functional improvement, and long-term dissatisfaction. The purpose of this prospective study was to measure the relationship between a diagnosis of depression or anxiety and Patient-Reported Outcomes Measurement Information System (PROMIS) domains, as well as determine which preoperative factors are associated with depression or anxiety in patients undergoing knee surgery. We hypothesized that preoperative depression and/or anxiety would be associated with worse preoperative pain, function, and general health status.

METHODS

Three-hundred and eighty-six patients undergoing knee surgery between 2015 and 2017 were administered health-related quality of life measures preoperatively, and their medical records were reviewed for relevant medical history. A propensity matched analysis was performed to determine clinical factors independently associated with preoperative depression and/or anxiety.

RESULTS

The overall study population consisted of 216 males and 170 females, with a mean age of 39.4 ± 16.2 years. From this overall cohort, 43 (11.1%) patients had a positive preoperative diagnosis of depression and/or anxiety. After controlling for covariate imbalances, preoperative depression/anxiety was independently associated with PROMIS Anxiety (p = 0.018), PROMIS Depression (p < 0.019), and Tegner pre-injury (p = 0.013) scores. Regression analysis also determined that preoperative depression/anxiety was independently associated with arthroscopic anterior cruciate ligament reconstruction (ACLR) (p = 0.004), total knee arthroplasty (TKA) (p = 0.019), and uni-compartmental knee arthroplasty (p < 0.05).

CONCLUSION

The results support our hypothesis that preoperative depression/anxiety is associated with worse preoperative pain, function, and general health status. Furthermore, PROMIS Anxiety and Depression tools offer a reliable means of measuring psychological distress in the orthopaedic knee population. Similar to other studies, we also noted psychological comorbidity to be independently associated with ACLR and TKA.

Association of age, sex and BMI with the rate of change in tibial cartilage volume: a 10.7-year longitudinal cohort study

Background

To describe the association of age, sex and body mass index with the rate of change of tibial knee cartilage volume over 10.7 years in a community-based sample of older adults.

Methods

Four hundred and eighty-one participants (49% female, mean age 60.8 years [range 51.1–79.7], 49% had knee pain and 58% radiographic osteoarthritis) were included. Tibial cartilage volume of the right knee was assessed on T1-weighted fat-suppressed 1.5 T MRI at baseline and 10.7 years. Data analyses were performed using linear regression models.

Results

The average rate of loss of cartilage volume was 1.2%/year (range 0.2–3.9%) with all participants losing cartilage volume over the study period. There was a significant association between age and loss of tibial cartilage volume in the medial (0.023%/year, 95% confidence interval [CI] 0.010 to 0.036%, p < 0.001), lateral (0.013%/year, 95% CI 0.003 to 0.023%, p = 0.012) and total tibia (0.018%/year, 95% CI 0.009 to 0.026%, p < 0.001). Higher body mass index at baseline and increases in body mass index over time were associated with a greater tibial cartilage loss at the medial (body mass index at baseline 0.040%/year, 95% CI 0.022 to 0.058%, p < 0.001; increases in body mass index 0.055%/year, 95% CI 0.018 to 0.093%, p = 0.004) but not lateral compartment. No evidence of non-linear relationships was observed. Compared to males, females lost more lateral tibial cartilage with increasing age (0.023%/year, 95% CI 0.003 to 0.043%, p = 0.024 for interaction).

Conclusions

Tibial cartilage volume declines at a faster rate with increasing age and body mass index in both males and females, particularly in the medial compartment. In contrast to the low rate of change in radiographs, our findings suggest that cartilage loss at the tibia is universal in this age group.

Variation in the Thickness of Knee Cartilage. The Use of a Novel Machine Learning Algorithm for Cartilage Segmentation of Magnetic Resonance Images

BACKGROUND

The variation in articular cartilage thickness (ACT) in healthy knees is difficult to quantify and therefore poorly documented. Our aims are to (1) define how machine learning (ML) algorithms can automate the segmentation and measurement of ACT on magnetic resonance imaging (MRI) (2) use ML to provide reference data on ACT in healthy knees, and (3) identify whether demographic variables impact these results.

METHODS

Patients recruited into the Osteoarthritis Initiative with a radiographic Kellgren-Lawrence grade of 0 or 1 with 3D double-echo steady-state MRIs were included and their gender, age, and body mass index were collected. Using a validated ML algorithm, 2 orthogonal points on each femoral condyle were identified (distal and posterior) and ACT was measured on each MRI. Site-specific ACT was compared using paired t-tests, and multivariate regression was used to investigate the risk-adjusted effect of each demographic variable on ACT.

RESULTS

A total of 3910 MRI were included. The average femoral ACT was 2.34 mm (standard deviation, 0.71; 95% confidence interval, 0.95-3.73). In multivariate analysis, distal-medial (-0.17 mm) and distal-lateral cartilage (-0.32 mm) were found to be thinner than posterior-lateral cartilage, while posterior-medial cartilage was found to be thicker (0.21 mm). In addition, female sex was found to negatively impact cartilage thickness (OR, -0.36; all values: P < .001).

CONCLUSION

ML was effectively used to automate the segmentation and measurement of cartilage thickness on a large number of MRIs of healthy knees to provide normative data on the variation in ACT in this population. We further report patient variables that can influence ACT. Further validation will determine whether this technique represents a powerful new tool for tracking the impact of medical intervention on the progression of articular cartilage degeneration.

Identify CRNDE and LINC00152 as the key lncRNAs in age-related degeneration of articular cartilage through comprehensive and integrative analysis

Background

Osteoarthritis (OA) is one of the most important age-related degenerative diseases, and the leading cause of disability and chronic pain in the aging population. Recent studies have identified several lncRNA-associated functions involved in the development of OA. Because age is a key risk factor for OA, we investigated the differential expression of age-related lncRNAs in each stage of OA.

Methods

Two gene expression profiles were downloaded from the GEO database and differentially expressed genes (DEGs) were identified across each of the different developmental stages of OA. Next, gene ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to annotate the function of the DEGs. Finally, a lncRNA-targeted DEG network was used to identify hub-lncRNAs.

Results

A total of 174 age-related DEGs were identified. GO analyses confirmed that age-related degradation was strongly associated with cell adhesion, endodermal cell differentiation and collagen fibril organization. Significantly enriched KEGG pathways associated with these DEGs included the PI3K–Akt signaling pathway, focal adhesion, and ECM–receptor interaction. Further analyses via a protein–protein interaction (PPI) network identified two hub lncRNAs, CRNDE and LINC00152, involved in the process of age-related degeneration of articular cartilage. Our findings suggest that lncRNAs may play active roles in the development of OA. Investigation of the gene expression profiles in different development stages may supply a new target for OA treatment.

Improvement of self-reported functional scores and thickening of quadriceps and femoral intercondylar cartilage under ultrasonography after single intra-articular injection of a novel cross-linked hyaluronic acid in the treatment of knee osteoarthritis

BACKGROUND

Most studies used hyaluronic acid (HA) requiring 3-5 intra-articular injections (IAJ) for knee osteoarthritis (KOA).

OBJECTIVE

We evaluated the efficacy of a single IAJ of a novel HA by measuring the thickness of quadriceps and femoral intercondylar cartilage (FIC) under ultrasonography (US) in addition to subjective self-reported measures.

METHODS

Forty-nine patients with KOA (Kellgren-Lawrence grades 2-3) received unilateral IAJ of HYAJOINT Plus to the worse knee and were assessed at baseline and 1, 3 and 6-months after IAJ. Outcome measures were the (1) Visual Analog Scale for pain (VAS), (2) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), (3) Lequesne's Index, (4) single-leg-stance duration (5) thigh circumference, and (6) thickness of quadriceps and FIC under US.

RESULTS

Forty-six patients completed the 6-month-follow-up study. All outcome measures improved significantly after HA injection (p< 0.001). Both VAS and WOMAC-pain subscale scores improved significantly at 1, 3, and 6 months (p< 0.01). The US thickness of the quadriceps and FIC improved significantly at both 3 and 6 months (p< 0.05). The Lequesne's index, single-leg-stance and thigh circumference improved significantly at 6 months (p< 0.01).

CONCLUSIONS

HYAJOINT Plus is effective both subjectively and objectively for 6 months and is safe as a treatment for KOA.

Association of childhood adiposity measures with adulthood knee cartilage defects and bone marrow lesions: a 25-year cohort study

OBJECTIVE

To describe the associations between childhood adiposity measures and adulthood knee cartilage defects and bone marrow lesions (BMLs) measured 25 years later.

METHODS

327 participants from the Australian Schools Health and Fitness Survey (ASHFS) of 1985 (aged 7-15 years) were followed up 25 years later (aged 31-41 years). Childhood measures (weight, height and skinfolds) were collected in 1985. Body mass index (BMI), overweight status and fat mass were calculated. Participants underwent 1.5 T knee magnetic resonance imaging (MRI) during 2008-2010, and cartilage defects and BMLs were scored from knee MRI scans. Log binomial regressions were used to examine the associations.

RESULTS

Among 327 participants (47.1% females), 21 (6.4%) were overweight in childhood. Childhood adiposity measures were associated with the increased risk of adulthood patellar cartilage defects (Weight relative risk (RR) 1.05/kg, 95% confidence interval (CI) 1.01-1.09; BMI 1.10/kg/m², 1.01-1.19; Overweight 2.22/yes, 1.21-4.08; fat mass 1.11/kg, 1.01-1.22), but not tibiofemoral cartilage defects. Childhood adiposity measures were not significantly associated with adulthood knee BMLs except for the association between childhood overweight status and adulthood patellar BMLs (RR 2.87/yes, 95% CI 1.10-7.53). These significant associations persisted after adjustment for corresponding adulthood adiposity measure.

CONCLUSION

Childhood adiposity measures were associated with the increased risk of adulthood patellar cartilage defects and, to a lesser extent, BMLs, independent of adulthood adiposity measures. These results suggest that adiposity in childhood has long-term effects on patellar structural abnormalities in young adults.

Human adipose-derived mesenchymal stem cells for osteoarthritis: a pilot study with long-term follow-up and repeated injections

AIM

This study aimed to evaluate the safety and therapeutic potential of autologous human adipose-derived mesenchymal stem cells (haMSCs) in patients with osteoarthritis.

MATERIALS & METHODS

Safety and efficacy of haMSCs were preclinically assessed in vitro and in BALB/c-nu nude mice. 18 patients were enrolled and divided into three dose groups: the low-dose, mid-dose and high-dose group (1 × 10⁷, 2 × 10⁷ and 5 × 10⁷ cells, respectively), provided three injections and followed up for 96 weeks.

RESULTS & CONCLUSION

The preclinical study established the safety and efficacy of haMSCs. Intra-articular injections of haMSCs were safe and improved pain, function and cartilage volume of the knee joint, rendering them a promising novel treatment for knee osteoarthritis. The dosage of 5 × 10⁷ haMSCs exhibited the highest improvement (ClinicalTrials.gov Identifier: NCT01809769).

Responsiveness of Infrapatellar Fat Pad Volume Change to Body Weight Loss or Gain: Data from the Osteoarthritis Initiative

Obesity is a potent risk factor for knee osteoarthritis (OA) that is driven by mechanical and potentially endocrine mechanisms, and it affects women more frequently than men. The infrapatellar fat pat (IPFP) represents a potential link between obesity, intra-articular inflammation and structural pathology. Here we investigate whether the IPFP is responsive to body weight loss/gain in women and how its responsiveness to weight change compares to that of subcutaneous fat (SCF) of the thigh. All female participants of the Osteoarthritis Initiative (OAI) with ≥10% weight loss/gain between baseline and a 2-year follow-up were included. Within-subject changes in IPFP volume and SCF cross-sectional areas (CSA) were determined from 3-T magnetic resonance imaging. Linear regression was used to assess the association between change in weight, IPFP volume, and SCF CSA. In the 38 participants with ≥10% weight loss over 2 years (age 59.3 ± 9.1 years, mean loss = 15.9%), there was a significant reduction in IPFP volume (-2.2%, p = 0.02) as well as in SCF CSA (-22%, p < 0.001). In the 34 participants with ≥10% gain (age 61.5 ± 8.7 years, mean gain = 15.9%), there was a significant increase in SCF CSA (+26%, p < 0.001) but not in IPFP volume (0.2%, p = 0.87). Weight change was significantly associated with SCF CSA change (r = 0.76, p < 0.001) but not with IPFP volume change (r = 0.11, p = 0.37). In this first longitudinal, observational study investigating the responsiveness of IPFP and SCF to weight change, IPFP morphology was found responsive to weight loss but not to weight gain. Overall, the responsiveness of the IPFP was substantially less than that of the SCF.

Reduced Osteoarthritis Severity in Aged Mice With Deletion of Macrophage Migration Inhibitory Factor

OBJECTIVE

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that is elevated in the serum and synovial fluid of patients with osteoarthritis (OA). This study was undertaken to investigate the potential role of MIF in OA in human joint tissues and in vivo in mice with age-related and surgically induced OA.

METHODS

MIF in conditioned media from human chondrocytes and meniscal cells and from cartilage explants was measured by enzyme-linked immunosorbent assay. The severity of OA was analyzed histologically in male wild-type and MIF^-/- mice at 12 and 22 months of age and following destabilization of the medial meniscus (DMM) surgery in 12-week-old MIF^-/- mice as well as in wild-type mice treated with a neutralizing MIF antibody. Synovial hyperplasia was graded in S100A8-immunostained histologic sections. Bone morphometric parameters were measured by micro-computed tomography.

RESULTS

Human OA chondrocytes secreted 3-fold higher levels of MIF than normal chondrocytes, while normal and OA meniscal cells produced equivalent amounts. Compared to age- and strain-matched controls, the cartilage, bone, and synovium in older adult mice with MIF deletion were protected against changes of naturally occurring age-related OA. No protection against DMM-induced OA was seen in young adult MIF^-/- mice or in wild-type mice treated with anti-MIF. Increased bone density in 8-week-old mice with MIF deletion was not maintained at 12 months.

CONCLUSION

These results demonstrate a differential mechanism in the pathogenesis of naturally occurring age-related OA compared to injury-induced OA. The inhibition of MIF may represent a novel therapeutic target in the reduction of the severity of age-related OA.

Geometric morphometric analysis reveals age-related differences in the distal femur of Europeans

Background

Few studies have looked into age-related variations in femur shape. We hypothesized that three-dimensional (3D) geometric morphometric analysis of the distal femur would reveal age-related differences. The purpose of this study was to show that differences in distal femur shape related to age could be identified, visualized, and quantified using three-dimensional (3D) geometric morphometric analysis.

Methods

Geometric morphometric analysis was carried out on CT scans of the distal femur of 256 subjects living in the south of France. Ten landmarks were defined on 3D reconstructions of the distal femur. Both traditional metric and geometric morphometric analyses were carried out on these bone reconstructions. These analyses were used to identify trends in bone shape in various age-based subgroups (<40, 40–60, >60).

Results

Only the average bone shape of the < 40-year subgroup was statistically different from that of the other two groups. When the population was divided into two subgroups using 40 years of age as a threshold, the subject's age was correctly assigned 80% of the time.

Discussion

Age-related differences are present in this bone segment. This reliable, accurate method could be used for virtual autopsy and to perform diachronic and interethnic comparisons. Moreover, this study provides updated morphometric data for a modern population in the south of France.

Conclusion

Manufacturers of knee replacement implants will have to adapt their prosthesis models as the population evolves over time.

The prevalence of radiographic and MRI-defined patellofemoral osteoarthritis and structural pathology: a systematic review and meta-analysis

BACKGROUND

Patellofemoral osteoarthritis (PF OA) is more prevalent than previously thought and contributes to patient's suffering from knee OA. Synthesis of prevalence data can provide estimates of the burden of PF OA.

OBJECTIVE

This study aims to conduct a systematic review and meta-analysis on the prevalence of PF OA and structural damage based on radiography and MRI studies in different populations.

METHODS

We searched six electronic databases and reference lists of relevant cross-sectional and observational studies reporting the prevalence of PF OA. Two independent reviewers appraised methodological quality. Where possible, data were pooled using the following categories: radiography and MRI studies.

RESULTS

Eighty-five studies that reported the prevalence of patellofemoral OA and structural damage were included in this systematic review. Meta-analysis revealed a high prevalence of radiographic PF OA in knee pain or symptomatic knee OA (43%), radiographic knee OA or at risk of developing OA (48%) and radiographic and symptomatic knee OA (57%) cohorts. The MRI-defined structural PF damage in knee pain or symptomatic population was 32% and 52% based on bone marrow lesion and cartilage defect, respectively.

CONCLUSION

One half of people with knee pain or radiographic OA have patellofemoral involvement. Prevalence of MRI findings was high in symptomatic and asymptomatic population. These pooled data and the variability found can provide evidence for future research addressing risk factors and treatments for PF OA.

TRIAL REGISTRATION NUMBER

PROSPERO systematic review protocol (CRD42016035649).

The interaction between weight and family history of total knee replacement with knee cartilage: a 10-year prospective study

OBJECTIVE

Although being overweight or obese is an important risk factor for the development of knee osteoarthritis (OA), the interplay between weight and genetic factors remains unclear. This study aimed to examine the associations between weight and knee cartilage volume/defects over 10 years in offspring having at least one parent with a total knee replacement (TKR) for primary knee OA and in controls without a knee OA family history.

METHOD

367 participants (183 offspring and 184 controls) aged from 26 to 61 years were recruited at baseline, and followed at 2 and 10 years later. T1-weighted magnetic resonance imaging (MRI) of the right knee was used to measure cartilage volume/defects at each time-point. Mixed-effects models were used with adjustment for potential confounders.

RESULTS

Study participants were middle-age adults (mean age 45 years, mean weight 77.5 kg at baseline). In multivariable analysis, increasing body weight was deleteriously associated with medial tibiofemoral cartilage volume (β = -0.28 ml, per 1 SD increase, 95% CI -0.49 to -0.07) and presence of medial tibiofemoral cartilage defects (RR = 1.27, per 1 SD increase, 95% CI 1.07 to 1.51) in offspring over 10 years. Similar associations were observed for lateral tibiofemoral cartilage volume (β = -0.19 ml, P = 0.059), and defects (RR = 1.24, P = 0.049). However, there were no statistically significant associations between weight and cartilage volume or defects in controls.

CONCLUSION

The adverse effects of increasing weight are stronger in the offspring of people with knee replacement for knee OA suggesting genetics-environment interaction with regard to overweight/obesity in the pathogenesis of knee OA particularly in the early stages.

Characteristics and associated factors of Klee cartilage lesions: preliminary baseline-data of more than 1000 patients from the German cartilage registry (KnorpelRegister DGOU)

INTRODUCTION

Knee cartilage lesions are very frequent in arthroscopic surgery. This multi-center-study was aimed to evaluate the distribution and possible associated factors of these pathologies in more than 1000 patients.

MATERIALS AND METHODS

The German cartilage registry (KnorpelRegister DGOU) started in 2013. In this paper, we present the baseline-data (distribution of knee cartilage lesions and the demographic data) of more than 1000 cases since the registries' start-up.

RESULTS

A total number of 47 centers were involved into this multicenter study. A total of 1071 patients primary were registered. Degenerative knees 629 times (61.8 %) and injured knees 302 times (29.6 %) were involved. In the remaining 89 knees (8.7 %) the genesis of cartilage lesions was unclear. Single defects were observed in 792 cases (77.6 %). Most frequently the medial femoral condyle or the patella was affected. In 78 knees (7.6 %) the main-defect was associated with a defect of the corresponding joint surface. In the remaining cases complex cartilage damages were found.

CONCLUSIONS

Our results are in confirmation with other multicenter studies. But these former studies did not differentiate into traumatic and degenerative lesions. Furthermore no characteristics were given regarding to single, kissing or complex lesions. Thus this database will be a sufficient instrument for the investigation of the "natural course" of cartilage lesions, but above all about the effectiveness of different treatment options.

Differences in subchondral bone size after one year in osteoarthritic and healthy knees

OBJECTIVE

Increase of subchondral bone area (tAB) in OA has been reported, but it remains unclear if this is specific to OA. We investigated differences in knee tAB after one year in healthy subjects and in those with radiographic OA (rOA).

METHOD

MR images of 899 right knees from the OA Initiative were acquired at baseline and one year follow-up (year-1). Medial and lateral tibial cartilage (MT and LT) and weight-bearing femoral cartilage (cMF and cLF) were segmented and tAB computed. Subjects were stratified into: healthy controls, pre-rOA (K&L grades 0 and 1, with OA risk factors), established rOA (K&L grades 2-4), and independently with regards to joint space narrowing (without, with medial, lateral and bilateral JSN). Primary analysis tested if tAB was different between baseline and year-1 in rOA. Exploratory analyses investigated whether: (1) tAB changes differed between healthy controls and those with rOA; (2) tAB differences were greater in higher K&L grades; and (3) tAB was different between baseline and year-1 in JSN. Significance was set at P < 0.0125.

RESULTS

Differences in tAB were found in rOA in MT, cMF and cLF (ranging from +0.2% to +0.4%; P < 0.001), but not in healthy controls or pre-rOA. Rates of change did not differ between groups. Within the JSN groups differences of 0.2-0.4% were found in the femur (P < 0.05).

CONCLUSION

We find that knee tABs differ in rOA between baseline and year-1, but the change was not greater than in healthy knees, and is restricted to the femur in JSN.

Serum hyaluronic acid concentration predicts the progression of joint space narrowing in normal knees and established knee osteoarthritis - a five-year prospective cohort study

Introduction

Serum hyaluronic acid (sHA) is a serum biomarker for knee osteoarthritis (OA). Although sHA concentration is elevated in patients with knee OA, the relationship between serum concentration and disease progression remains unclear. We examined the relationship between sHA concentration and radiographic progression of knee OA in a cohort of individuals followed for 5 years.

Methods

We prospectively enrolled 444 individuals and measured their sHA concentrations at baseline. Anterior-posterior weight bearing knee radiographs were obtained at baseline and the 5-year endpoint. Osteoarthritic knee changes were classified according to Kellgren–Lawrence (KL) grade, and joint space narrowing (JSN) was measured using a Knee Osteoarthritis Computer-Aided Diagnosis (KOACAD) system. Correlations between sHA concentration, progression in KL grade, and JSN were assessed using regression models, taking into account potentially confounding factors.

Results

OA progressed from KL grades 0 or 1 in 129 of the 323 knees, and from KL grades 2 or 3 in 61 of the 119 knees. Higher sHA concentrations were correlated with KL grade progression (p = 0.004). The mean JSN, as assessed by KOACAD over 5 years, was 0.23 ± 0.55 mm, and sHA concentration was positively correlated with progression of JSN in KL grades 0 or 1 (p = 0.021) and KL grades 2 or 3 (p = 0.008) knees.

Conclusion

Serum HA concentration was positively correlated with progression of KL grade. sHA was also positively correlated with progression of JSN in knees with and without OA, suggesting that sHA concentration may be a useful predictor of knee OA progression.

Computational investigation of the time-dependent contact behaviour of the human tibiofemoral joint under body weight

The knee joint is one of the most common sites for osteoarthritis, the onset and progression of which are believed to relate to the mechanical environment of cartilage. To understand this environment, it is necessary to take into account the complex biphasic contact interactions of the cartilage and menisci. In this study, the time-dependent contact behaviour of an intact and a meniscectomized human tibiofemoral joint was characterized under body weight using a computational model. Good agreement in the contact area and femoral displacement under static loads were found between model predictions of this study and published experimental measurements. The time-dependent results indicated that as loading time progressed, the contact area and femoral vertical displacement of both intact and meniscectomized joints increased. More load was transferred to the cartilage-cartilage interface over time. However, the portions of load borne by the lateral and medial compartments did not greatly vary with time. Additionally, during the whole simulation period, the maximum compressive stress in the meniscectomized joint was higher than that in the intact joint. The fluid pressure in the intact and meniscectomized joints remained remarkably high at the condyle centres, but the fluid pressure at the cartilage-meniscus interface decreased faster than that at the condyle centres as loading time progressed. The above findings provide further insights into the mechanical environment of the cartilage and meniscus within the human knee joint.

Anthropometric difference of the knee on MRI according to gender and age groups

The purpose of this study was to analyze the anthropometric data from MRI images that were obtained from the non-arthritic knees in Asian adults, and to identify the existence of morphologic differences between age groups. This cross-sectional study included knee MR images of 535 patients (273 males, 262 females) taken for the evaluation of soft-tissue injuries, excluding cases with cartilage defect and malalignment. The age, gender, height, and BMI were also assessed. The patients were grouped into three different 20-year age groups (20-39, 40-59, and 60-79). The MRI analysis was performed on the anthropometric parameters of distal femur and posterior tibial slope. Age-related differences were found in femoral width, distance from the distal and posterior cartilage surface to the medial/lateral epicondyle, medial posterior condylar offset (PCO), and posterior condylar angle (PCA) (all P < 0.001), but not in lateral PCO, and medial/lateral tibial slopes. In the analysis of covariance analyses, significant interaction between gender and age groups was found in most parameters, but not in PCA, distance from the posterior cartilage surface to the medial epicondyle, or medial tibial slope. We found anthropometric differences among age groups exist in most of distal femoral parameters, but not in posterior tibial slope. The results of this study can be used by manufacturers to modify prostheses to be suitable for the future Asian elderly population.

Familial effects on structural changes relevant to knee osteoarthritis: a prospective cohort study

OBJECTIVE

Genetic factors play an important role in the pathogenesis of knee osteoarthritis (OA), but which knee structural changes mediate this is unclear. This study aimed to describe the differences in knee structural changes over 8-10 years between offspring having at least one parent with total knee replacement (TKR) for severe primary knee OA and controls with no family history of knee OA.

DESIGN

115 offspring (mean age 45 years) with a family history of TKR for severe knee OA were compared with 104 (mean age 46 years) controls. T1 or T2-weighted fat saturated magnetic resonance imaging (MRI) was performed respectively to evaluate knee cartilage defects, bone marrow lesions (BMLs), meniscal extrusion and tears at baseline and 10 years. Multivariate logistic regression model was used to adjust for potential confounders.

RESULTS

Offspring had a greater increase in cartilage defect score (1.03 vs 0.52, P = 0.007) and meniscal extrusion score (0.28 vs 0.10, P = 0.027) over 10 years, and a greater increase in meniscal tear score (0.40 vs 0.10, P = 0.012) over 8 years in the medial but not the lateral tibiofemoral compartment. Changes in BMLs over 8-years were not different between the two groups. These associations were independent of potential confounders, and strengthened after further adjustment for each other.

CONCLUSION

With the exception of BMLs, offspring with a family history of knee OA have a greater risk of increases in multiple knee structural abnormalities in the medial tibiofemoral compartment suggesting pleiotropic familial effects.

Osteoarthritis and telomere shortening

Osteoarthritis is the most common disease of joints caused by degradation of articular cartilage and subchondral bone. It is classified as primary form with unknown cause and as secondary form with known etiology. Genetic and epigenetic factors interact with environmental factors and contribute to the development of primary osteoarthritis. Thus far, many polymorphisms associated with osteoarthritis have been identified and recent studies also indicate the involvement of epigenetic factors (e.g., telomere shortening) in the initiation of this disorder. Accelerated shortening of telomeres was detected in osteoarthritis and other age-related diseases. Studies revealed that telomere length is severely reduced in blood leukocytes and chondrocytes of patients with osteoarthritis, and this may contribute to the initiation and development of osteoarthritis, whose major cause is still unknown.

The relationship between clinical characteristics, radiographic osteoarthritis and 3D bone area: data from the osteoarthritis initiative

BACKGROUND

Radiographic measures of osteoarthritis (OA) are based upon two dimensional projection images. Active appearance modelling (AAM) of knee magnetic resonance imaging (MRI) enables accurate, 3D quantification of joint structures in large cohorts. This cross-sectional study explored the relationship between clinical characteristics, radiographic measures of OA and 3D bone area (tAB).

METHODS

Clinical data and baseline paired radiographic and MRI data, from the medial compartment of one knee of 2588 participants were obtained from the NIH Osteoarthritis Initiative (OAI). The medial femur (MF) and tibia (MT) tAB were calculated using AAM. 'OA-attributable' tAB (OA-tAB) was calculated using data from regression models of tAB of knees without OA. Associations between OA-tAB and radiographic measures of OA were investigated using linear regression.

RESULTS

In univariable analyses, height, weight, and age in female knees without OA explained 43.1%, 32.1% and 0.1% of the MF tAB variance individually and 54.4% when included simultaneously in a multivariable model. Joint space width (JSW), osteophytes and sclerosis explained just 5.3%, 14.9% and 10.1% of the variance of MF OA-tAB individually and 17.4% when combined. Kellgren Lawrence (KL) grade explained approximately 20% of MF OA-tAB individually. Similar results were seen for MT OA-tAB.

CONCLUSION

Height explained the majority of variance in tAB, confirming an allometric relationship between body and joint size. Radiographic measures of OA, derived from a single radiographic projection, accounted for only a small amount of variation in 3D knee OA-tAB. The additional structural information provided by 3D bone area may explain the lack of a substantive relationship with these radiographic OA measures.

No damage of joint cartilage of the lower limbs in an ultra-endurance athlete--an MRI-study

Background

Osteoarthritis is an increasing burden in an ageing population. Sports, especially when leading to an overstress of joints, is under suspicion to provoke or at least accelerate the genesis of osteoarthritis. We present the radiologic findings of a 49-years old ultra-endurance athlete with 35 years of training and competing, whose joints of the lower limbs were examined using three different types of magnetic resonance imaging, including a microscopic magnetic resonance imaging coil. To date no case report exists where an ultra-endurance athlete was examined such detailed regarding overuse-injuries of his joints.

Case presentation

A 49 years old, white, male ultra-endurance athlete reporting no pain during training and racing and with no significant injuries of the lower limbs in his medical history was investigated regarding signs of chronic damage or overuse injuries of the joints of his lower limbs.

Conclusion

Despite the age of nearly 50 years and a training history of over 35 years, the athlete showed no signs of chronic damage or overuse injuries in the joints of his lower limbs. This leads to the conclusion that extensive sports and training does not compulsory lead to damages of the musculoskeletal system. This is a very important finding for all endurance-athletes as well as for their physicians.

Quantitative magnetic resonance imaging assessment of cartilage status: a comparison between young men with and without anterior cruciate ligament reconstruction

PURPOSE

To assess the cartilage status of the knee joints using magnetic resonance imaging at least 2 years after anterior cruciate ligament reconstruction (ACLR) in young adult men.

METHODS

Thirty young male patients with unilateral ACLR and 15 age-matched and body mass index--matched healthy men (controls) participated in this study. All participants underwent quantitative magnetic resonance imaging scans. Three-dimensional dual-echo steady-state sagittal images were segmented using solid model software to calculate the mean cartilage thickness, and multi-echo sagittal images were segmented with Siemens software (Siemens, Erlangen, Germany) to determine the T2 relaxation time of each cartilage plate.

RESULTS

There was no statistically significant difference in the mean thickness of each cartilage plate between the ACLR and control groups (P = .9616 for lateral femoral cartilage, P = .5962 for lateral tibial cartilage, P = .9328 for patellar cartilage, P = .9712 for trochlear cartilage, P = .4408 for medial femoral cartilage, and P = .1933 for medial tibial cartilage). The ACLR group had significantly higher T2 values than the control group in the lateral femoral cartilage (P < .001), lateral tibia (P = .0011), trochlea (P = .0028), medial femur (P < .001), and medial tibia (P < .001). In addition, the patella showed no difference in T2 values between the 2 groups (P = .2152). The medial compartment cartilage showed a much higher percentage change in cartilage T2 values in the ACLR group.

CONCLUSIONS

Although no difference in cartilage thickness was detected between the ACLR group and the control group, the mean T2 relaxation time in the ACLR patients was significantly longer than that in control subjects.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Prevalence and clinical significance of chondromalacia isolated to the anterior margin of the lateral femoral condyle as a component of patellofemoral disease: observations at MR imaging

OBJECTIVE

To determine the prevalence of chondromalacia isolated to the anterior margin of the lateral femoral condyle as a component of patellofemoral disease in patients with anterior knee pain and to correlate it with patient demographics, patellar shape, and patellofemoral alignment.

MATERIALS AND METHODS

Retrospective study over a 1-year period reviewing the MR knee examinations of all patients who were referred for assessment of anterior knee pain. Only patients with isolated lateral patellofemoral disease were included. Age, gender, distribution of lateral patellofemoral chondromalacia, and grade of cartilaginous defects were documented for each patient. Correlation between the distribution of lateral patellofemoral chondromalacia and patient demographics, patellar shape, and indices of patellar alignment (femoral sulcus angle and modified Q angle) was then ascertained.

RESULTS

There were 50 patients (22 males, 28 females) with anterior knee pain and isolated patellofemoral disease. The majority of the patients (78 %) had co-existent disease with grade 1 chondromalacia. No significant correlation was found between patients with chondromalacia isolated to the anterior margin of the lateral femoral condyle and age, gender, patellar shape, or modified Q angle (p > 0.05). However, patients with chondromalacia isolated to the anterior margin of the lateral femoral condyle had a shallower femoral sulcus angle (mean 141.8°) compared to the patients with lateral patellar facet disease (mean 133.8°) (p = 0.002).

CONCLUSIONS

A small percentage of patients with anterior knee pain have chondromalacia isolated to the anterior margin of the lateral femoral condyle. This was associated with a shallower femoral sulcus angle.

The age-related changes in cartilage and osteoarthritis

Osteoarthritis (OA) is closely associated with aging, but its underlying mechanism is unclear. Recent publications were reviewed to elucidate the connection between aging and OA. With increasing OA incidence, more senior people are facing heavy financial and social burdens. Age-related OA pathogenesis is not well understood. Recently, it has been realized that age-related changes in other tissues besides articular cartilage may also contribute to OA development. Many factors including senescence-related secretory phenotypes, chondrocytes' low reactivity to growth factors, mitochondrial dysfunction and oxidative stress, and abnormal accumulation of advanced glycation end products (AGEs) may all play key roles in the pathogenesis of age-related OA. Lately, epigenetic regulation of gene expression was recognized for its impact on age-related OA pathogenesis. Up to now, few studies have been reported about the role of miRNA and long-noncoding RNA (lncRNA) in age-related OA. Research focusing on this area may provide valuable insights into OA pathogenesis. OA-induced financial and social burdens have become an increasingly severe threat to older population. Age-related changes in noncartilage tissue should be incorporated in the understanding of OA development. Growing attention on oxidative stress and epigenetics will provide more important clues for the better understanding of the age-related OA.

Associations between measures of adiposity over 10 years and patella cartilage in population-based asymptomatic women

OBJECTIVE

Osteoarthritis (OA) most commonly affects the patellofemoral compartment of the knee, and is a major cause of pain and disability. Structural changes that evolve prior to the onset of symptoms can be visualised using magnetic resonance imaging (MRI). There is little known information about the role of adiposity on the early structural changes in the patella cartilage in younger, asymptomatic adult females.

METHODS

One hundred and sixty asymptomatic women (20-49 years) participating in the Geelong Osteoporosis Study underwent knee MRI (2006-8). Weight and body mass index (BMI) were measured 10 years prior (1994-7, baseline) and at the time of MRI (current), with change over the period calculated (current-baseline). Relationships between measures of adiposity and patella cartilage volume and defects were examined.

RESULTS

After adjustment for age and patella bone volume, there was a reduction of 13 ml (95% confidence interval (95% CI), -25.7, -0.55) in patella cartilage volume for every 1 unit increase in current BMI, and a reduction of 27 ml (95% CI -52.6, -1.5) per BMI unit increase over 10 years (P=0.04 for both). No significant association was observed between baseline BMI and patella cartilage volume (P=0.16). Increased baseline and current weight and BMI were associated with increased prevalence of patella cartilage defects (all P<0.001).

CONCLUSIONS

Adiposity and weight gain during midlife are associated with detrimental structural change at the patella in young to middle-aged healthy non-osteoarthritic women. Maintaining a healthy weight and avoiding weight gain in younger asymptomatic women may be important in the prevention of patellofemoral OA.

T1rho MRI relaxation in knee OA subjects with varying sizes of cartilage lesions

BACKGROUND

The purpose of this investigation is to evaluate the T(1ρ) relaxation times of articular cartilage surrounding focal defects in the tibiofemoral joint.

METHODS

Quantitative cartilage assessment was performed using 3T MRI with T(1ρ) mapping in 19 healthy individuals and 44 OA patients. Sagittal T2-weighted fast spin echo (FSE) images were acquired for lesion assessment. Differences were determined using analysis of variance (ANOVA).

RESULTS

Cartilage lesions were found in 37% of controls, and 93% of OA patients. Meniscal tears were found in 16% of controls and 57% of OA patients. We observed no difference in T(1ρ) relaxation times when comparing cartilage immediately surrounding a focal defect, and the remaining cartilage within that compartment. The medial femoral condyle (MFC) had the highest incidence of cartilage defects. MFC and medial meniscus posterior horn T(1ρ) were higher in subjects having multiple focal lesions (p = 0.048, pb 0.001 respectively) and extensive full thickness lesions (p = 0.009, pb 0.001 respectively) compared to subjects with no MFC defects. Significant elevations in T(1ρ) of the adjacent compartment (medial tibia) and medial meniscus were observed in subjects with MFC lesions.

CONCLUSION

Increased relaxation times in the involved compartment as well as the adjacent compartment and associated meniscus underscore the interdependence of these structures at bearing load. However, no differences in cartilage composition immediately surrounding a defect were noted. Finally, an association was observed between cartilage defects and meniscal damage in advanced disease.

CLINICAL RELEVANCE

Cartilage defects were not associated with degeneration in the immediately adjacent cartilage.

Knee cartilage defects in a sample of older adults: natural history, clinical significance and factors influencing change over 2.9 years

OBJECTIVE

To describe the natural history of knee cartilage defects, and their relationship to cartilage volume loss and risk of knee replacement in a longitudinal study of older adults.

DESIGN

395 randomly selected older adults (mean age 62.7 years) had magnetic resonance imaging of their right knee at baseline and approximately 2.9 years later to determine cartilage defect grade (0-4), cartilage volume, medial and lateral tibial bone size, and presence of bone marrow lesions (BMLs). Height, weight, body mass index (BMI) and radiographic osteoarthritis were measured by standard protocols.

RESULTS

At baseline higher grade cartilage defects (grade ≥2) were significantly associated with age, BMI, lateral tibial bone size, BMLs, and radiographic osteoarthritis. Over 2.9 years, the average defect score increased statistically significantly in all compartments; however, the majority of defects remained stable and regression of defects was rare. Baseline factors associated with increase in defect score over 2.9 years were radiographic osteoarthritis, tibial bone size, BMI and being female. In multivariate analysis, baseline cartilage defect grade predicted cartilage volume loss at the medial tibia, lateral tibia and patella over 2.9 years (β = -1.78% to -1.27% per annum per 1 grade increase, P < 0.05 for all comparisons), and risk of knee replacement over 5 years (odds ratio (OR) = 1.73 per 1 grade increase, P = 0.001).

CONCLUSION

Knee cartilage defects in older adults are common but less likely to regress than in younger life. They independently predict cartilage volume loss and risk of knee replacement, suggesting they are potential targets for intervention.

Body fat is associated with increased and lean mass with decreased knee cartilage loss in older adults: a prospective cohort study

OBJECTIVE

To determine the associations between body composition at baseline and knee cartilage loss over 2.9 years in older adults.

METHODS

A total of 395 randomly selected subjects (mean 62 years, range 51-81, 50% female) were studied at baseline and 2.9 years later. T1-weighted fat-suppressed magnetic resonance imaging of the right knee was performed to determine knee cartilage volume and tibial bone area at baseline and follow-up. Height, weight and radiographic osteoarthritis were measured by standard protocols at baseline. Fat mass and lean mass were measured by dual-energy X-ray absorptiometry at baseline.

RESULTS

Tibial cartilage volume decreased by 2.0-2.7% per annum. In multivariable analysis, annual change in medial cartilage volume was negatively and significantly associated with body mass index (β: -0.14% per kg m(-2), 95% confidence interval (CI): -0.25%, -0.02%), percentage total body fat (β: -0.19% per %, 95% CI: -0.30%, -0.07%) and percentage trunk fat (β: -0.10% per %, 95% CI: -0.19%, -0.02%), and positively associated with percentage lean mass (β: 0.20% per %, 95% CI: 0.08%, 0.32%). Change in lateral tibial cartilage volume was also significantly associated with percentage total body fat (β: -0.11% per %, 95% CI: -0.21%, -0.001%) and total lean mass (β: 0.13% per kg, 95% CI: 0.04%, 0.22%). These were independent of sex and age even though both were also significant predictors.

CONCLUSIONS

Body fat adversely affects tibial cartilage loss over time, whereas lean mass is protective. Strategies aimed at reducing body fat but increasing lean mass may reduce knee cartilage loss in older people.

Quantitative magnetic resonance imaging (MRI) morphological analysis of knee cartilage in healthy and anterior cruciate ligament-injured knees

PURPOSE

To analyze the morphological change in the cartilage of the knee after anterior cruciate ligament (ACL) injury by comparing with that of the intact contralateral knee.

METHODS

A total of 22 participants (12 male and 10 female patients) who had unilateral ACL injury underwent MRI scan of both the injured and intact contralateral knees. Sagittal plane images were segmented using a modeling software to determine cartilage volume and cartilage thickness in each part of the knee cartilage that were compared between the ACL-injured and the intact contralateral knees. Furthermore, the male and female patients' data were analyzed in subgroups.

RESULTS

The ACL-injured knees had statistically significant lower total knee cartilage volume than the intact contralateral knees (P = 0.0020), but had similar mean thickness of total knee cartilage (not significant: n.s.). In the male subgroup, there was no significant difference in cartilage volume and thickness between normal and ACL-injured knees. In the female subgroup, the ACL-injured knees demonstrated statistically significant difference in total knee cartilage volume (P = 0.0004) and thickness (P = 0.0024) compared with the normal knees. The percentage change in the cartilage thickness in women was significantly greater than that in men.

CONCLUSION

Cartilage volume was significantly smaller in the ACL-injured knees than in the contralateral intact knees in this cohort. Women tended to display greater cartilage volume and thickness change after ACL injury than men. These findings indicated that women might be more susceptible to cartilage alteration after ACL injuries.

LEVEL OF EVIDENCE

III.

An anatomic study of coronoid cartilage thickness with special reference to fractures

BACKGROUND

Current coronoid fracture classification systems are based on fragment size and configuration using plain radiographs and/or computed tomography (CT). During surgery, coronoid fracture fragments appear much larger than anticipated because cartilage is radiolucent and therefore not accounted for with preoperative imaging. The purpose of this imaging study was to quantify the articular cartilage thickness of the coronoid, with reference to coronoid fractures.

MATERIALS AND METHODS

Twenty-four cadaveric ulnae were dissected, imaged with CT, and analyzed by use of image analysis software. Thirteen identifiable landmarks were chosen on the coronoid, olecranon, and proximal radioulnar joint to measure articular cartilage thickness. Intraobserver reliability and interobserver reliability were determined.

RESULTS

Cartilage thickness was highest at the coronoid tip, with a mean of 3.0 mm (range, 1.7-4.6 mm). Cartilage thickness at the tip correlated inversely with age (P < .01) and correlated strongly with overall ulnar height and ulnar length (P < .05). All measurements had excellent intraobserver and interobserver reliability.

CONCLUSION

The thickness of cartilage on the coronoid tip is not inconsequential. The results of this study indicate that a 2-mm coronoid tip fracture on CT scan may actually appear to be a mean of 5 mm thick when viewed at the time of surgery. Clinically, this is important because it may alter the classification, the decision to treat, or the type of fixation used. Importantly, biomechanical cadaveric studies assessing coronoid injuries have incorporated cartilage thickness into coronoid size measurements when creating simulated fractures; therefore, it is critical that the conclusions of such biomechanical studies be scrutinized with regard to their clinical recommendations. Surgeons should be aware of these discrepancies.