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Abstract Magnetic resonance imaging (MRI) is widely regarded as the primary modality for the morphological assessment of cartilage and all other joint tissues involved in osteoarthritis. 2D fast spin echo fat-suppressed intermediate-weighted (FSE FS IW) sequences with a TE between 30 and 40ms have stood the test of time and are considered the cornerstone of MRI protocols for clinical practice and trials. These sequences offer a good balance between sensitivity and specificity and provide appropriate contrast and signal within the cartilage as well as between cartilage, articular fluid, and subchondral bone. Additionally, FS IW sequences enable the evaluation of menisci, ligaments, synovitis/effusion, and bone marrow edema-like signal changes. This review article provides a rationale for the use of FSE FS IW sequences in the morphological assessment of cartilage and osteoarthritis, along with a brief overview of other clinically available sequences for this indication. Additionally, the article highlights ongoing research efforts aimed at improving FSE FS IW sequences through 3D acquisitions with enhanced resolution, shortened examination times, and exploring the potential benefits of different magnetic field strengths. While most of the literature on cartilage imaging focuses on the knee, the concepts presented here are applicable to all joints. Key points 1. MRI is currently considered the modality of reference for a “whole-joint” morphological assessment of osteoarthritis. 2. Fat-suppressed intermediate-weighted sequences remain the keystone of MRI protocols for the assessment of cartilage morphology, as well as other structures involved in osteoarthritis. 3. Trends for further development in the field of cartilage and joint imaging include 3D FSE imaging, faster acquisition including AI-based acceleration, and synthetic imaging providing multi-contrast sequences.

Objectives: By analyzing the protective effect and mechanism of tobacco on knee joint cartilage in rats, this paper studies the effect of tobacco on knee joint recovery of college students after sports. Methods: Firstly, the main subunits of nAChRs were systematically studied by using the rat knee arthritis model α 7 and α 4 and β To clarify the correlation between nAChRs and the occurrence and development of OA. Then, the OA rat model prepared by iodoacetic acid was used as the experimental object to observe the protective effect of nicotine on knee osteoarthritis cartilage in rats. Results: The histological changes of rats in MIA group were obvious after operation. The results of light microscope score and Mankin's score at 15 and 30 days were significantly higher than those in con group. Of right knee cartilage in rats in MIA group α 7, α 4 and β The expression of 2 did not change significantly on the 15th day, but increased significantly on the 30th day compared with the blank control group. Conclusion: Nicotine has a protective effect on knee bone and joint cartilage and promotes the accelerated recovery of knee bone and joint after exercise.. Key words: nicotine, knee joint, cartilage, recovery after exercise.

A research method was developed to analyse the tribological properties of cartilage tissue. Based on the literature data and the possibility of obtaining samples of appropriate dimensions, the frequency and amplitude of friction tests were adopted. Based on the previously conducted preliminary tests, other test parameters were proposed, such as the frictional contact load and the number of test runs. It was assumed that the results of the research will be the friction coefficient and the wear intensity of the tribological system. According to the developed method, a series of verification tests was carried out in which the friction contact was lubricated in various ways with the selected lubricants. The results of tests of animal cartilage in nonlubricated contact were used as the reference basis for all the tested associations. The friction tests showed good method resolution and satisfactory repeatability. In the case of wear characteristics, a greater scatter of test results was observed. It is probably related to the varied geometrical structure of the cartilage surface as well as the elastic properties of the bone on which the tissue was placed. The correctness of the obtained results and a relatively good resolution of the tribological test method were found.

To compare three-dimensional (3D) nasal forms after definitive correction of unilateral cleft lip (UCL)-nose using an extended spreader cartilage graft with/without a cross-lap joint cartilage graft technique. Twenty-four patients with UCL who underwent definitive nose correction using an extended spreader cartilage graft with a cross-lap joint technique (CLJ group) and fifteen patients with UCL who underwent nose correction without a cross-lap joint technique (non-CLJ group) were enrolled in this study. Pre- and postoperative 3D nasal forms were compared between the two groups. The CLJ group demonstrated more successful recovery of the nasal tip and anterior nasal ridge in the center of the face (P 0.01), and the higher nasal tip was maintained for more than 1 year (P = 0.008). The differences in the cephalo-caudal heights of the nasal alar groove and curvatures of the alar groove arch were successfully improved in both CLJ and non-CLJ groups. The nasal angles on lateral profiles did not change in either group. An extended spreader cartilage graft with a cross-lap joint technique facilitates satisfactory recovery of the nasal tip in the center of the face and a higher nasal tip, avoiding over-projection in the definitive correction of UCL-nose.

Osteoarthritis is a degenerative joint disease that is associated with damage to joint cartilage. One way to diagnose mild pain or the onset of OA early is to do a rontgen examination. The aim of the study was to determine the differences in the degree of osteoarthritis of the knee joint AP position erect with the AP supine position. This research was conducted in the hospital. Academic Jaury Jusuf Putera Makassar April - June 2019. This type of research is descriptive analytical, data collection techniques using questionnaires, sampling techniques carried out by accidental sampling analysis. Data analysis using statistics Presentation of data is presented in the form of graph tables accompanied by narration. Based on the results of the study it can be concluded that the Erect Position has an assessment score with an average of 7.20 while the Supine position with an average of 8.00. From the results of the statistical test obtained p value (0.455)> 0.05 means that there is no statistically significant difference in scores between Erect and Supine positions. It is expected that the radiology officer chooses the right projection that is in accordance with the patient's general condition. If it is possible for the patient to be examined with the projection of AP Weight-Bearing Standing, the officer uses the projection, otherwise the officer can use the AP Supine or AP Erect position because the two positions have no significant differences based on the results of the existing research.

The objective of this study is to investigate the expression of enzymes involved in the sulfation of articular cartilage from proximal metacarpophalangeal (PMC) joint cartilage and distal metacarpophalangeal (DMC) joint cartilage in children with Kashin-Beck disease (KBD). The finger cartilage samples of PMC and DMC were collected from KBD and normal children aged 5-14 years old. Hematoxylin and eosin staining as well as immunohistochemical staining were used to observe the morphology and quantitate the expression of carbohydrate sulfotransferase 3 (CHST-3), carbohydrate sulfotransferase 12 (CHST-12), carbohydrate sulfotransferase 13 (CHST-13), uronyl 2-O-sulfotransferase (UST), and aggrecan. In the results, the numbers of chondrocyte decreased in all three zones of PMC and DMC in the KBD group. Less positive staining cells for CHST-3, CHST-12, CHST-13, UST, and aggrecan were observed in almost all three zones of PMC and DMC in KBD. The positive staining cell rates of CHST-12 were higher in superficial and middle zones of PMC and DMC in KBD, and a significantly higher rate of CHST-13 was observed only in superficial zone of PMC in KBD. In conclusion, the abnormal expression of chondroitin sulfate sulfotransferases in chondrocytes of KBD children may provide an explanation for the cartilage damage, and provide therapeutic targets for the treatment.

Background: Knee osteoarthritis (KOA) refers to a chronic deteriorating disease distinguished by degeneration of joint cartilage. Many clinical studies have demonstrated that isokinetic muscle strength training can improve muscle function in patients with KOA. However, although such studies deduce an excellent effect, the results remain controversial. Therefore, the present systematic review seeks to explore the curative effects of isokinetic muscle strength training to establish if it can improve muscle function in patients experiencing KOA. Methods: This review will entail a systematic review and a comprehensive examination to establish all randomized controlled studies covering curative effects of isokinetic muscle strength training to improve muscle function in patients with KOA. We will obtain data from PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure, and WanFang databases from inception to September 2021. In addition, the study will employ the criterion postulated by Cochrane to ascertain a quality evaluation and risk assessment of the studies included for analysis. Also, we will employ relative risk, mean differences, and standardized mean differences with 95% confidence intervals to estimate the effective measures. Also, we will employ Cochran Q test and I2 statics to assess heterogeneity among the 2 studies. Results: Overall, this study anticipates providing accurate results and balanced inferences on curative effects of isokinetic muscle strength training for improving muscle function in patients with KOA. Conclusion: The study's inferences will offer evidence to decide whether isokinetic muscle strength training is an effective measure for improving muscle function in patients with KOA.

This study was to investigate the effects of 13 weeks of long-distance cycling on biomarkers of joint cartilage, muscle damage and inflammation. All subjects in this study were seven participants of the “One Korea New-Eurasia Peace Cycle Expedition”, in which they rode cycles from Berlin, Germany to Seoul, Korea for thirteen weeks. The total course of the expedition was divided into three sub-courses: course 1 (from Berlin to Moscow), course 2 (from Moscow to Ulaanbaatar) and course 3 (from Ulaanbaatar to Seoul). All the selected participants rode 87.4 km/day (course 1), 70.4 km/day (course 2) and 57.6 km/day (course 3) on average, respectively. We collected their blood samples before the expedition in Seoul (S1), after course 1 in Moscow (M), after course 2 in Ulaanbaatar (U) and after the expedition in Seoul (S2), to analyze biomarkers of joint cartilage damage (Cartilage Oligomeric Matrix Protein; COMP), muscle damage (Creatine Phosphokinase; CPK, Lactate Dehydrogenase; LDH, Myoglobin), inflammation (Interleukin-6; IL-6, Interleukin-1β; IL-1β, Tumor Necrosis Factor-α; TNF-α, C-Reactive Protein; CRP) and stress hormone (Cortisol). According to this result, COMP (S1; 188.37 ± 46.68 ng/mL) showed a significant increase after the expedition course 1 (M; 246.69 ± 51.69 ng/mL, p = 0.012) and course 2 (U; 237.09 ± 62.57 ng/mL, p = 0.047), and recovered to the stable state after expedition course 3 (S2; 218.46 ± 34.78. p = 0.047). Biomarkers of muscle damage (CPK, LDH and Myoglobin) and inflammation (IL-6, IL-1β, TNF-α and CRP) were not significantly changed in all courses, but CRP (S1; 1.07 ± 0.76 ng/mL) showed a tendency to decrease after the expedition course 1 (M; 0.3 ± 0.1 mg/mL, p = 0.044). Lastly, the Cortisol level significantly increased in all courses (per p < 0.05), but the Cortisol level after expedition course 3 (S2; 21.00 ± 3.65 mg/mL) was lower than that of after the expedition course 1 (M; 24.23 ± 2.47 mg/mL, p = 0.028). In summary, it seems that repetitive and continuous 50–90 km/day of cycling can increase joint cartilage damage risk and stress hormone temporarily. However, this result suggests that the appropriate intensity of cycling for thirteen weeks does not increase physical damage, and rather enhances the human body to adapt to exercise training.

BackgroundThe walking ability of many broilers is characterised by slight or definite defects categorised as gait scores (GS) 1 and 2. The present study aimed to examine potential relationships between GSs and indicators of body morphology, leg pathology, tibia strength and wooden breast in Ross 308 broilers assessed as GS ≤ 2.MethodsAt 38 days of age, GS and live body weight of 179 birds was recorded. Each bird was examined post-mortem for signs of wooden breast, contact dermatitis and a range of leg pathologies. Weights of different body parts and tibia strength were quantified.ResultsWithin sex, GS increased with increasing live body weight (p = 0.020). There was a tendency for an effect of GS on prevalence of footpad dermatitis (p = 0.086) and dislocated femoral joint cartilage (p = 0.059) where both pathologies increased in frequency with increasing GS. Greater load was required to fracture tibia from GS2 than GS0 birds (p = 0.040).ConclusionsWithin this relatively small data set, no strong relationships between GS ≤ 2 and indicators of body morphology, leg pathology, tibia strength and wooden breast in Ross 308 broilers were found, except for the live terminal body weight. Further studies, involving larger data sets are required for full clarification.

This review summarizes research on many of the potential applications of photosensitized crosslinking of tissue proteins in surgery and current knowledge of the photochemical mechanisms underlying formation of the covalent protein-protein crosslinks involved. Initially developed to close wounds or reattach tissues, protein photocrosslinking has also been demonstrated to stiffen and strengthen tissues, decrease inflammatory responses and facilitate tissue bioengineering. These treatments appear to result largely from crosslinks within and between collagen molecules in tissue that typically form by an oxygen-dependent mechanism. Surgical applications discussed include sealing wounds in skin, cornea and bowel; reattaching severed nerves, blood vessels and tendons; strengthening cornea and vein; reducing capsular contracture after breast implants; and regenerating joint cartilage.

Objectives: Different materials are currently being used experimentally to accelerate cartilage healing and to obtain hyaline cartilage. We aimed to investigate the effect of platelet-rich fibrin on joint cartilage healing. Methods: Twenty rats were used in this study. platelet-rich fibrin was obtained from 4 rats, and the remaining 16 rats were randomly divided into two groups (4 and 8 weeks). Both knee joints were prepared, and an osteochondral defect was created at the femoral condyle in all rats. platelet-rich fibrin was placed into the osteochondral defect of the right knee, while the left knee joint was used as a control. Groups were sacrificed after 4 and 8 weeks, respectively. Results: According to the O'Driscoll score, there were no significant differences between the right and left knee scores in group 4 weeks (p = 0.820). However, the right knee scores were significantly different than the left knee scores in group 8 weeks (p < 0.001). Defects were completely filled with cartilage tissue after 8 weeks in the platelet-rich fibrin group. Conclusions: Similar to its role in various tissues, platelet-rich fibrin is an effective biomaterial that enhances the healing of osteochondral defects.

Cartilage degradation frequently occurs during the postmenopausal period due to a decrease in type 2 collagen and constitutes a condition affected by the level of estrogen in the body. The purpose of this study is to prove that such post-menopausal reductions in estrogen levels influence the type 2 collagen expression in cartilage. Oophorectomies were per-formed on 54 Rattus norvegicus subjects and each of which was subsequently assigned to one of six different groups. 17β-estradiol present in the blood of the subjects was examined by means of ELISA technique, while the expression of MMP-13 and type 2 collagen in their knee joint cartilage was assessed immunohistochemically. A significant post-oopho-rectomy decrease of 17β-estradiol was detected in subjects (p

The cartilage surgeon is a comprehensive knee surgeon. A sound understanding of meniscal, ligamentous, and patellofemoral issues is required. Cartilage injuries are often a result of trauma or aberrant anatomy. Excessive pressure or shear forces on articular cartilage will decrease the longevity of its pristine surface. With limited native regeneration potential, specific techniques must be employed to restore or reconstruct the articular surface. This chapter discusses a complete evaluation of the knee including history, physical exam, and imaging. Core components will be obtained for all patients, but it is important to note that not every test or study will be employed uniformly. As with any sound evaluation, it will begin by conducting a comprehensive history.

Joint cartilage lesions are seen as a major musculoskeletal system problem that have a negative effect on quality of life and are observed at increasing rates [1]. In a prospective examination of 1000 knee arthroscopies by Hijelle et al., chondral and osteochondral lesions were determined incidentally at the rate of 61%. In a similar series, grade III–IV lesions at least 1 cm2 in size were determined in 5.3% of patients aged ≤40 years [2]. According to this, it can be said that focal symptomatic cartilage lesions are frequently seen in young patients.

Symptomatic osteochondral lesions of the talus (OLT) often require surgical treatment. Surgical interventions can be broadly divided into reparative procedures and replacement procedures. Reparative techniques include bone marrow stimulation, autologous chondrocyte implantation, and matrix-induced autologous chondrocyte implantation, while replacement techniques include osteochondral autograft and allograft transplantation. More recently, biological adjuncts and scaffolds have been shown to have promising evidence and may be utilized alongside surgery to improve healing potential. This chapter reviews the current evidence for surgical management and use of biological adjuncts for the treatment of OLT.

Background Femoroacetabular impingement (FAI) has attracted increasing attention over the past few decades. We aim to evaluate FAI research and predict research hot spots quantitatively and qualitatively. Methods The publications in FAI research between 2000 and 2019 were assimilated from the Web of Science Core Collection of Clarivate Analytics. The retrieved data were evaluated by the bibliometric method. Software CiteSpace 5.7.R1, VOSviewer 1.6.15, and the Online Analysis Platform of Literature Metrology ( http://bibliometric.com/ ) were used to analyze and identify the hot spots and trends in this field. Results A total of 2471 originals articles that fulfilled the study requirements were obtained. The number of manuscripts on FAI has experienced rapid growth, especially after 2009. The United States of America was the leading country for publication and to the collaboration network. FAI, osteoarthritis, hip arthroscopy, labral reconstruction, pathomorphology, outcome, rehabilitation, and joint cartilage are some of the high-frequency keywords in co-occurrence cluster analysis and cocited reference cluster analysis. Burst detection analysis of top keywords revealed that outcomes, instability, labral reconstruction, adolescent, and risk factor were newly emerged research hot spots. Conclusion The understanding of FAI has been improved significantly during the past two decades. Present studies focused on identifying the optimal method to treat labral pathology, outcome assessment of either surgeries or conservative managements, and predicting midterm and long-term outcomes. Together these studies exert critical implications for decision-making and management for FAI.

Background Magnetic resonance (MR) T2 and T2* mapping sequences allow in vivo quantification of biochemical characteristics within joint cartilage of relevance to clinical assessment of conditions such as hip osteoarthritis (OA). Purpose To evaluate an automated immediate reliability analysis of T2 and T2* mapping from MR examinations of hip joint cartilage using a bone and cartilage segmentation pipeline based around focused shape modelling. Study type Technical validation. Subjects 17 asymptomatic volunteers (M: F 7:10, aged 22–47 years, mass 50–90 kg, height 163-189 cm) underwent unilateral hip joint MR examinations. Automated analysis of cartilage T2 and T2* data immediate reliability was evaluated in 9 subjects (M: F 4: 5) for each sequence. Field strength/sequence A 3 T MR system with a body matrix flex-coil was used to acquire images with the following sequences: T2 weighted 3D-trueFast Imaging with Steady-State Precession (water excitation; 10.18 ms repetition time (TR); 4.3 ms echo time (TE); Voxel Size (VS): 0.625 × 0.625 × 0.65 mm; 160 mm field of view (FOV); Flip Angle (FA): 30 degrees; Pixel Bandwidth (PB): 140 Hz/pixel); a multi-echo spin echo (MESE) T2 mapping sequence (TR/TE: 2080/18–90 ms (5 echoes); VS: 4 × 0.78 × 0.78 mm; FOV: 200 mm; FA: 180 degrees; PB: 230 Hz/pixel) and a MESE T2* mapping sequence (TR/TE: 873/3.82–19.1 ms (5 echoes); VS: 3 × 0.625 × 0.625 mm; FOV: 160 mm; FA: 25 degrees; PB: 250 Hz/pixel). Assessment Automated cartilage segmentation and quantitative analysis provided T2 and T2* data from test-retest MR examinations to assess immediate reliability. Statistical tests Coefficient of variation (CV) and intraclass correlations (ICC2, 1) to analyse automated T2 and T2* mapping reliability focusing on the clinically important superior cartilage regions of the hip joint. Results Comparisons between test-retest T2 and (T2*) data revealed mean CV's of 3.385% (1.25%), mean ICC2, 1′s of 0.871 (0.984) and median mean differences of −1.139ms (+0.195ms). Conclusion The T2 and T2* times from automated analyses of hip cartilage from test-retest MR examinations had high (T2) and excellent (T2*) immediate reliability.

Objective The aim of this study was to determine the effects of activity and cam morphology on cartilage composition during adolescence and investigate the development of cartilage composition with age. Design Cross-sectional observational cohort study of individuals from football club academies and an age-matched control population, aged 9 to 18 years. Assessments included questionnaires and T2-mapping of hips. Primary imaging outcome measures were T2 relaxation time of acetabular and femoral cartilage, average alpha angle, and lateral epiphyseal extension. Results The cohort consisted of 109 elite male footballers, 49 male controls, and 51 female controls. Elite male footballers had an acetabular cartilage T2 value 4.85 ms greater than male controls ( P < 0.001). A significant positive correlation existed between Physical Activity Questionnaire Score and acetabular cartilage T2 value (coefficient 1.07, P < 0.001) and femoral cartilage T2 value (coefficient 0.66, P = 0.032). Individuals with a closed physis had an acetabular cartilage T2 value 7.86 ms less than individuals with an open physis. Acetabular cartilage T2 values decreased with age in elite footballers. No correlation existed between alpha angle and anterosuperior acetabular cartilage T2 value and no difference in T2 value existed between individuals with and without cam morphology. Conclusions This study demonstrates that high activity levels may significantly affect acetabular cartilage composition during adolescence, but cam morphology may not detrimentally affect cartilage composition until after adolescence.

Joints are a necessary anatomic and functional element of the organ of locomotion. Hyaline cartilage is a very important element of a joint in physiological terms. Joint cartilage is subjected to injuries associated with non-physiological loading and excessive abnormal mobility caused by ligament instability. These can lead to damage to the surface of the cartilage and the development of defects. Until now there has been no „golden standard” for treating injuries to joint cartilage. The goal of this treatment is to sustain knee function at a level that is tolerable and acceptable to the patient. Three major minimally invasive techniques for treating damage of the surface of the joints are currently available, namely 1) the microfracture technique, which stimulates bone marrow. Regenerative processes promote the formation of fibrohyaline cartilage. 2) transplantation of osteocartilaginous allo- and autogeneic cylinders. 3) in vitro chondrocyte culture and transplantation of these chondrocytes to sites with cartilage defects. This review describes both the historical and modern techniques of joint cartilage treatment as well as new perspectives related to the use of biomaterials in the healing of cartilage defects.

In this chapter, the architecture of human joints, articular surfaces, and characteristics of the movements of the joint shapes will be discussed. Joint classifications based on their structural and functional features, sub-classifications, the degree of movements and the definitions of specific joint tissues such as the joint cartilage, synovial membrane, ligaments are described. The anatomic relationship that provides mobility and dynamic stability to the joint structures, osteokinematics, arthrokinematics, closed packet, and open packet joint and their relationship with joint play, concave-convex rule, open and closed kinematic chain are described in detail. In addition, the effect of injury and bone aging also will be pointed out.

Manganese dioxide nanoparticles target chondrocytes, protecting cartilage tissue from inflammation-induced oxidative damage.

Objective Automatic segmentation for biochemical cartilage evaluation holds promise for an efficient and reader-independent analysis. This pilot study aims to investigate the feasibility and to compare delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) hip joint assessment with manual segmentation of acetabular and femoral head cartilage and dGEMRIC hip joint assessment using automatic surface and volume processing software at 3 Tesla. Design Three-dimensional (3D) dGEMRIC data sets of 6 patients with hip-related pathology were assessed (1) manually including multiplanar image reformatting and regions of interest (ROI) analysis and (2) automated by using a combined surface and volume processing software. For both techniques, T1Gd values were obtained in acetabular and femoral head cartilage at 7 regions (anterior, anterior-superior, superior-anterior, superior, superior-posterior, posterior-superior, and posterior) in central and peripheral portions. Correlation between both techniques was calculated utilizing Spearman’s rank correlation coefficient. Results A high correlation between both techniques was observed for acetabular (ρ = 0.897; P < 0.001) and femoral head (ρ = 0.894; P < 0.001) cartilage in all analyzed regions of the hip joint (ρ between 0.755 and 0.955; P < 0.001). Conclusions Automatic cartilage segmentation with dGEMRIC assessment for hip joint cartilage evaluation seems feasible providing high to excellent correlation with manually performed ROI analysis. This technique is feasible for an objective, reader-independant and reliable assessment of biochemical cartilage status.

Background Assessment of the joint cartilage using ultrasound imaging is important. Objective Our aim was to investigate the reliabilities of ultrasonographic measurements for talus dome (TCT) and metacarpal cartilage thicknesses (MCT). Methods Twenty healthy volunteers were recruited in the study. Every day, five physiatrists measured eight joint cartilage thicknesses. They repeated all the measurements in five consecutive days. Results Intra-observer intraclass correlation coefficient (ICC) values were "excellent" for all MCTs, except for the 3rd left MCT on the 1st day, 4th left MCT on the 1st day and 4th right MCT on the 3rd day which were "good". They were "excellent" for the TCT measurements, except for the left side on the 3rd day and the right side on the 4th day which were "good". Inter-observer ICC values pertaining to the 2nd MCT measurements were "excellent" for all sonographers. Third and 4th MCT measurements (at least one side) were "excellent" for four and three sonographers, respectively. On the other hand, while TCT measurements were "excellent" for 4 sonographers. Conclusions Our results have shown that sonographic measurements of MCT and TCT have good to excellent reliabilities in healthy adults. These findings support the use of ultrasound for cartilage assessment in various diseases.

Fatigue resistance of hydrogels is critical to their applications in load-bearing sites of soft tissues that are usually subjected to continuous loadings, such as joint cartilage. However, hydrogels usually swell under physiological conditions and exhibit inevitable fatigue during excessive mechanical loadings. Here we show that hydrogels cross-linked by multivalent host–guest interactions can effectively dissipate a large fraction of the loading energy (>50%) under excessive compressions (over 80% strain, 1000 cycles) despite their high water contents (95%) under physiological conditions. No fatigue is observed in such highly swollen hydrogels during continuous cyclic compressions. We demonstrate that such hydrogels can be used as 3D cell carriers for excessive mechanical stimulation of the encapsulated stem cells, making them promising soft biomaterials for tissue engineering.

Some of the most pressing health problems of the industrial society are the damage and degeneration of articular cartilage associated with the limited capacity of tissues to regenerate. The review describes the existing and developing technologies for the recovery and replacement of damaged joint cartilage tissue. The results obtained are analyzed covering two major areas: the stimulation of regeneration of damaged cartilage tissue and the growing of cartilage tissue elements in bioreactors.

OBJECTIVE A causal link between ballet, hip pain, and pathology has not been established. Change in ballet dancers' hip pain and cartilage defect scores were investigated over 5 years. DESIGN Longitudinal. SETTING Professional ballet company. PARTICIPANTS Twenty-one professional ballet dancers (52% men). INDEPENDENT VARIABLES Baseline and follow-up Copenhagen Hip and Groin Outcome Score (HAGOS-pain subscale); incidence of hip-related pain and levels of dance participation collected daily over 5 years; bony morphology measured on baseline 3T magnetic resonance imaging (MRI). MAIN OUTCOME MEASURE Change in cartilage defect score on MRI between baseline and 5-year follow-up. RESULTS Cartilage scores did not increase in 19 (90%) dancers. There was one new cartilage defect and one progressed in severity. At follow-up, all 6 dancers with cartilage defects were men. Group HAGOS pain scores were high 97.5 (7.5) and not related to cartilage defects (P = 0.12). Five (83%) dancers with baseline cartilage defects reported HAGOS pain scores

Background: Osteoarthritis (OA) remains one of the most common osteopathy for centuries, which can be attributed to multiple risk factors including mechanical and biochemical ones. More and more studies verified that inflammatory cytokines play important roles in the progression of OA, such as tumor necrosis factor-alpha (TNF-α). In this study, we aimed to investigate the relationship between epigenetic manifestations of TNF-? and the pathogenesis of OA. Methods: Totally, 37 OA patients’ cartilage was collected through the knee joint and 13 samples of articular cartilage as healthy control was collected through traumatic amputation. Real-time PCR, Western blot and ELISA analysis were performed to observe the expression of target genes and proteins in collected samples. Results: Compared with the healthy control group, TNF-? was over-expressing in cartilage which was collected from OA patients. DNA hypomethylation, histone hyperacetylation and histone methylation were observed in the TNF-? promoter in OA compared with normal patients, and we also studied series of enzymes associated with epigenetics. The results showed that by increasing DNA methylation and decreasing histone acetylation in the TNF-? promoter, and TNF-? over-expression in OA cartilage was suppressed, histone methylation has no significant correlation with OA. Conclusion: In conclusion, the changes of epigenetic status regulate TNF-α expression in the cells, which are pivotal to the OA disease process. These results may give us a better understanding of OA and may provide new therapeutic options.

Background Degeneration of the osteocartilaginous structures due to synovial inflammatory process is a feature of juvenile idiopathic arthritis (JIA)1. While anthropometry difference has been reported between Asian and Caucasian2, Asian specific age- and gender-related normal standard reference values should be established before ultrasound (US) measurement of cartilage thickness (Cth) becomes standard procedure in the clinic. Objectives The standard cartilage thickness in Asian children population Methods A cross-sectional study was performed in 100 healthy Asian children (including 48 girls and 52 boys, age between 5 to 12 years-old). Bilateral knees, ankles, wrists, second metacarpophalangeals (MCPs) and proximal interphalangeals (PIPs) were measured using US. Children’s body weight and body height were also recorded for later adjustment. Results We observed no difference in the Cth between right and left knees, ankles and wrists but MCPs and PIPs. Cartilage thickness in the large joints such as ankles and knees differed between sexes (p Conclusion Cartilage thickness measurement with US in small joints may be biased. A standard reference of Cth for Asians in the knee, ankle and wrist joints between age 5- to 12 have been proposed. References [1] Naredo, E. et al. Longitudinal power Doppler ultrasonographic assessment of joint inflammatory activity in early rheumatoid arthritis: predictive value in disease activity and radiologic progression. Arthritis Rheum57, 116-124, doi:10.1002/art.22461 (2007). [2] Yue, B. et al. Differences of knee anthropometry between Chinese and white men and women. J Arthroplasty26, 124-130, doi:10.1016/j.arth.2009.11.020 (2011). Disclosure of Interests None declared

Hip joint cartilage contact stresses are clinically relevant and necessary to improve our understanding of hip osteoarthritis. Therefore, the objective of this paper is to assess the contact pressure changes during series of dynamic postures such as slow walking, normal walking, fast walking, descending stairs and ascending stairs. A standard anatomical model is built from CT images and twenty kinematical models are constructed using a motion capture system. A two-step adjusted-iterative closest point method is proposed to register the anatomical model with the motion capture recorded kinematical model. After the registration, acetabular cartilage contact pressure is analyzed by a finite element method. According to simulation results among twenty subjects, the contact pressure distribution of walking and stairs movements are mostly uniform during a cycle of movement. The peak of contact pressure appears at the transition location from superior to posterior. The peak of contact pressure happens almost at the time of heel-strike. The contact area is changing from anterior to superior-posterior and ending at anterior for all the activities. These results demonstrate the trends for normal hip contact pressure in cartilage during daily activities. These results also provide guidance for the diagnosis of osteoarthritis. The location at transition from superior to posterior should be paid more attention in the diagnosis of osteoarthritis. And the osteoarthritis patient should try to avoid the movement of ascending and descending stairs.

The contact stresses in the hip joint cartilage are relevant with clinical hip osteoarthritis. Therefore, the objective of this paper is to discover the contact pressure changes in acetabular cartilage during series of dynamic postures such as slow walking, normal walking, fast walking, descending stairs and ascending stairs. Subject-specific anatomical models are built from CT images and kinematical models are constructed using a motion capture system. A two-step adjusted-iterative closest point method is proposed to register the anatomical model with the motion capture recorded kinematical model. After the registration, acetabular cartilage contact pressure is analyzed by a finite element method. According to simulation results, the distribution of walking and stairs movements for contact pressure are mostly uniform during cycle of movement. The peak of contact pressure appears at the heel-strike. The contact area spreads from anterior to superior-posterior and ending at anterior for all the activities. These results provide a basic understanding for the hip contact pressure in cartilage during daily activities and they could be used to analyze the pathologic hips in the clinical research.

Objective To identify if the time of day and pre-imaging exercise matter while performing T2* mapping of hip joint cartilage at 3 T. Design Nine asymptomatic healthy volunteers (mean age 27.4 ± 4.0 years) with no obvious morphological evidence of cartilage damage were enrolled. The MRI protocol included a double-echo steady state (DESS) sequence for morphological cartilage assessment and a multi-echo data image combination sequence for the T2* measurement. T2* values were obtained between 8 and 11 a.m., between 3 and 6 p.m., and after 50 knee-bends at several time points of each measurement (0, 15, 30, 45, 60 minutes). Results We observed no differences ( P = 0.47) between the T2* values obtained in the morning (T2* = 22.9 ± 3.0 ms) and those measured in the afternoon (T2* = 23.2 ± 3.2 ms). We also observed no statistically significant differences between the T2* values at different time points ( P = 0.67) or after 50 knee-bends ( P = 0.43). Conclusions Timing of the scan and pre-imaging exercise clearly did not matter in this modality. This study consolidates the value of T2* imaging in hip joint cartilage that seems to be independent of diurnal effects and physical activity prior to MRI.

The surface of an articular cartilage human joint, coated with phospholipid bilayers or multi-layers, plays an important role in the surface-active phospholipid lubrication, friction, and wear during human limb movement. The biological bi-layer is a thin polar membrane composed of two layers of phospholipids that have a hydrophilic phosphate head (from the outside) and a hydrophobic tail (from the inside) consisting of two fatty acid chains. These membranes are flat sheets that form a continuous barrier around all cells. Synovial fluid (SF) in the human joint gap contains glycoprotein, lubricin (proteinglycan 4), and hyaluronidase, i.e. an enzyme that produces hialuron acid and ±10% phospholipids. Because the mechanism of surface articular phospholipid lubrication (SAPL) has been a frequently controversial subject in the past decade, this fact requires showing the hydrodynamic description in the form of a mathematical model of the abovementioned problem and its particular solution. To give a description of this model, it is necessary to recognize the variations of the dynamic viscosity of synovial fluid as a function of parameters depending on the presence of many phospholipid particles. To these parameters belong power (exponent) concentration of hydrogen ions (pH), cartilage wet ability (We), collagen fibre concentration in synovial fluid, and a created electrostatic field on the phospholipid membrane. Based on the Young-Laplace-Kelvin Law, initial achievements presented in scientific papers and our own investigations illustrated in this paper, the decrements, and increments of synovial fluid dynamic viscosities versus pH and wet ability (We) increases, simultaneously taking into account the influence of the intensity of charges in the electrostatic field. Moreover, this study considers the influence of collagen fibre concentration on the dynamic viscosity of synovial fluid. Based on initial considerations performed by virtue of the developed SAPL, it may be stated that the charge increments from low to high values of the electrostatic field is connected with viscosity increases of synovial fluid but only simultaneously with the pH index and cartilage wet ability variations.

During classical journal bearing lubrication the lubricant viscosity is independent of physical properties of cooperating bodies, which is well known by virtue of Hersey-Stribeck (H-S) curve presenting friction coefficient vs. Hersey number = viscosity´velocity/pressure. The result obtained by the H-S is valid for two cooperating bodies with homogeneous, isotropic properties, and for Newtonian oils omitting the elastohydrodynamic effects. In the presented paper, we take into account the two cooperating human joint cartilage surfaces, which, after new AFM measurements, have non-homogeneous hypo- or hyper-elastic properties, and the synovial fluid has non-Newtonian features. Moreover, the cartilage surface during human limb motion and during the squeezing and boosted squeezing effects gains important small deformations. From the abovementioned description, it follows that the H-S result cannot be acceptable in human joint lubrication [L. 1–6]. During human joint hydrodynamic lubrication, we observe the influence of the material coefficients of the hypo- and hyper-elastic cartilage tissue on the apparent viscosity of non-Newtonian synovial fluid occupying the thin joint gap limited by the two cartilage superficial layers. This problem has not been considered in scientific papers describing the hydrodynamic lubrication of the human joint. This problem attains significant meaning because, after numerous AFM laboratory measurements confirmed by the literature achievements, it follows that the joint cartilage tissue with a thin polar membrane made of two lipid molecules has no isotropic but anisotropic properties in general. These membranes are flat sheets that form a continuous barrier around the cartilage cells. Non-homogeneous, anisotropic biological bodies as distinct from classical isotropic materials have the various values of elasticity, hypoelasticity, or hyper-elasticity modules on individual places and directions. These places, loaded by the same forces, tend to various displacements and strains. In consequence, mutually connected physical implications caused by virtue of synovial fluid flow velocity and shear rates changes, indicate to us the conclusion that the dynamic viscosity of synovial fluid gains value variations caused by the cartilage’s physical properties during human joint lubrication.

The aim of this study was to investigate the effect of epinephrine-enhanced computed tomographic arthrography (CTA) on the image sharpness of the lateral and medial glenohumeral ligaments (LGHL and MGHL, respectively), biceps tendon (BT) and joint cartilage (JC) in the canine shoulder. The shoulders of eight normal dogs were examined using a 4-slice helical CT scanner. The right shoulders were injected with Iohexol and the left shoulders with a mixture of Iohexol and epinephrine. CTA images were obtained after 1, 3, 5, 9, 13, 20 and 30 min and the image sharpness of the intra-articular structures in both shoulders was graded for visibility. The attenuation values were measured to examine the persistence of contrast appearance. Admixture of epinephrine and Iohexol significantly improved the image sharpness of the LGHL and the BT, especially on delayed CTA images. The use of epinephrine did not negatively affect post-CTA recovery.

Osteoarthritis is a degenarative joint disease which affects joint cartilage. Almost 80% patients movement are limited and 25 % of them can not evev perform daily activities. Due to its chronic and progressive nature, socio-economic impacts in many developed and developing countries are enormous. This study aimed to determine the distribution of patient with knee osteoarthritis in Pertamina Bintang Amin Hospital Bandar Lampung. Methods: This study is a decriptive cross sectional approach with secondary data taken from medical record. Thirty eight cases were evaluated in this study from January 2019 – Mei 2019. The variables observed include age, sex, body mass index (BMI) and occupations. Results: The result show that 36,8 % of the samples were aged 50-59 years,78,9 % of the samples were female, 71,1 % of the samples had BMI obesity, 60,5 % and 43,2 % were work as housewife. A total of 23 of 38 knee samples had grade III, and 3 of 38 knee samples alsohad grade I, and as many as 7 of the 38 knee samples had a” very severe” clinical gradation. These result may be due to patients who have low grade gradation clinics and have received medical attention at the level I health facility or II. Conclusion: Form the result of this study, it can be concluded that age, sex, BMI, occupations and Kellgren-Lawrence scoring system at Pertamina Bintang Amin Bandar Lampung is in comformity with research that has been done in many places and theories that exist. Reference: Apley, Ag., & Louis Solomon, (2017). Osteoarthritis. In David Warwick (ED). System of Orthopaedics and Trauma (10th Ed., pp. 91-105). London, UK: CRC Press. Fransen M.Bridgett L. March L.Hoy D. Penserga E. Brooks P.The Epidemiolgy os Osteoarthritis in Asia. International Journal of Rheumatic Diseases 2011;14;113-212. Zhang Fu – Quang,Wu Ming – Xia, Liu Xian – Xiang, Gender and Sex distribution of middle and old aged people with osteoarthritis in Fuzhou, Vol II, May 2009. American of Orthopaedic Surgeon, Relatioship of Osteoarthritis and Biochemical Reactions, Journal of Bone and Joint Surgery, 2004 volume II.

Introduction: Hyalofast grafting with microfracture is a new minimally invasive treatment method being proposed for joint cartilage defects. This study was done to measure the clinical efficacy of Hyalofast grafting after microfractures. Methods: Forty-six patients were assessed for knee function using knee injury and osteoarthritis outcome score (KOOS) after undergoing microfracture and Hyalofast grafting surgery. We further divided the 46 patients into a group of 10 patients who had no associated procedures done with the microfracture and Hyalofast grafting surgery. All patients had magnetic resonance imaging (MRI) of the affected knee pre-surgery and two patients had MRI done post-surgery. Due to another unrelated injury, we were also able to obtain further arthroscopic findings of another patient’s knee 18 months after microfracture and Hyalofast grafting. Results: There was a statistically significant improvement in all categories of the KOOS (symptoms, pain, daily living, sports and quality of life) compared between years 1, 2 and 3 against pre-surgery. For the subgroup of Hyalofast only, there was a statistically significant improvement in symptoms, pain and daily living categories of the KOOS compared between years 1, 2 and 3 against pre-surgery. Conclusions: Our study shows that Hyalofast grafting after microfracture is a viable alternative to treatment for patients with grade 4 cartilage ulcers.

Penyakit Osteochondral Lesion of the Talus (OLT) adalah kelainan pada tulang talus di lapisan subchondral yang berupa lesi osteochondral pada talar dome dengan konsekuensi abnormalitas pada tulang rawan sendi talar. Pasien biasanya datang berobat ke tenaga kesehatan dengan keluhan yang tidak spesifik dan dengan gejala seperti nyeri pada pergelangan kaki, bengkak serta berkurangnya berkurangnya ruang gerak. Penegakan diagnosis bisa dilakukan dengan anamnesis, pemeriksaan fisik dan pemeriksaan penunjang sederhana seperti foto X-ray maupun pemeriksaan penunjang canggih seperti CT-Scan dan MRI. Tatalaksana OLT bervariasi. Tatalaksana pada OLT tergantung dari tahapan lesi, kronisitasnya, dan keluhan simtomatis yang menyertainya. Pasien dengan keluhan simtomatis yang akut dan non-displaced sering diberikan terapi nonoperatif biasanya berupa terapi konservatif dengan imobilisasi. Lesi yang tidak berhasil atau tidak menunjukkan perbaikan dalam keluhan simtomatisnya setelah 3 sampai 6 bulan, serta lesi dengan displacement dapat direncanakan untuk terapi operatif. Ada beberapa macam tehnik operatif yang dapat dilakukan untuk menyembuhkan OLT. Tehnik operatif ini dapat dikategorikan menjadi cartilage repair , cartilage regeneration dan cartilage replacement techniques. Kata kunci: osteochondral lesion of the talus , patofisiologi, tatalaksana ABSTRACT Osteochondral Lesion of the Talus (OLT) is an abnormality in the talus bone in the subchondral layer in the form of osteochondral lesions in the talar dome with consequent abnormalities in the talar joint cartilage. Patients usually come to a health care provider with nonspecific complaints and with symptoms such as pain in the ankles, swelling and reduced space for movement. The diagnosis can be made with a history, physical examination and simple investigations such as X-rays and sophisticated investigations such as CT-Scan and MRI. The management of OLT varies. The management of OLT depends on the stage of the lesion, its chronicity, and the accompanying symptomatic complaints. Patients with acute and non-displaced symptomatic complaints are often given nonoperative therapy usually in the form of conservative therapy with immobilization. Lesions that are unsuccessful or show no improvement in symptomatic complaints after 3 to 6 months, and lesions with displacement can be planned for operative therapy. There are several types of operative techniques that can be done to cure OLT. These operative techniques can be categorized into cartilage repair, cartilage regeneration and cartilage replacement techniques . Keywords: osteochondral lesion of the talus , patophysiology, treatment

Adropin is newly discovered peptide hormone. Osteoarthritis (OA) is a kind of joint disease characterized by progressive joint cartilage loss and joint pain. The present study was carried out to investigate adropin and tumor necrosis factor alpha (TNF-α) levels and the relationship between adropin in patients with knee OA classified by Kellgren-Lawrence (KL). A total of 60 knee OA patients and 30 healthy controls were included in this study. KL grading was carried out using the radiographic findings. Demographic characteristics and laboratory parameters were recorded. Adropin and TNF-α levels were determined by using enzyme-linked immunosorbent assay (ELISA). Adropin level was lower in the knee OA patients compared with the healthy controls (p 0.001), whereas TNF-α level was higher (p 0.001). Adropin level was negatively correlated with TNF-α level, blood white blood cell (WBC) count, and neutrophil-lymphocyte ratio (NLR). However, there was a significant decrease in adropin level and an increase in TNF-α level parallel to the increase in the KL grade. In addition, serum adropin level was found to be significantly lower in KL grade 1 groups compared with healthy controls (p 0.01). There was a decrease in adropin level parallel to the increase in the body mass index (BMI), and there was a statistically significant decrease in adropin level in knee OA patients higher than BMI 30 (p 0.01). Mean NLR of KL grade 4 was significantly increased compared with other grades (p 0.05). The consequence of the present study suggested that serum adropin level could be used as a new biomarker indicating the early grade of knee OA.

OBJECTIVE: The aim of this study was to analyze the blood serum levels of CTX-II in professional indoor soccer players, at three different times during one season: at the start of the pre-season, four months later (a time that marks the middle of the season) and at the end of the season.METHODS: Fourteen male soccer players of mean age 19 years were included. Blood samples of 3 mL were collected from each individual. The samples were analyzed by means of Elisa tests.RESULTS: There was a significant increase in the serum level of CTX-II in the indoor soccer players, from the beginning to the end of the season (p< 0.01).CONCLUSION: These data suggest that joint degradation had occurred in these soccer players, by the end of this period. It is evident that further studies are needed, with methodological rigor, so as to make an effective contribution toward precise elucidation of the etiology of this osteoarthritis and its relationship with the biomarkers, as a tool for early diagnosis. OBJETIVO: Analisar os níveis séricos sanguíneos de CTX-II em atletas profissionais de futebol de salão, em três momentos distintos durante uma temporada: no início da pré-temporada, quatro meses após (período que marca o meio da temporada) e no fim da temporada.MÉTODOS: Foram incluídos 14 atletas do gênero masculino e média de idade de 19 anos. Foram coletados 3 mL de sangue de cada indivíduo. As amostras foram analisadas pelo teste do tipo Elisa.RESULTADOS: Houve aumento significativo dos níveis séricos de CTX-II nos atletas de futebol de salão, comparando-se o início e o fim de uma temporada (p < 0,01).CONCLUSÃO: Esses dados sugerem a ocorrência de degradação articular nos atletas, ao término desse período. Fica evidente a necessidade de futuros estudos, com rigor metodológico, que possam contribuir efetivamente para a elucidação precisa da etiologia da OA e sua relação com os biomarcadores como instrumento de diagnóstico precoce.

ResumoObjetivoAnalisar os níveis séricos sanguíneos de CTX‐II em atletas profissionais de futebol de salão, em três momentos distintos durante uma temporada: no início da pré‐temporada, quatro meses após (período que marca o meio da temporada) e no fim da temporada.MétodosForam incluídos 14 atletas do gênero masculino e média de idade de 19 anos. Foram coletados 3 mL de sangue de cada indivíduo. As amostras foram analisadas pelo teste do tipo Elisa.ResultadosHouve aumento significativo dos níveis séricos de CTX‐II nos atletas de futebol de salão, comparando‐se o início e o fim de uma temporada (p

This study investigated the postmortem molecular changes that articular cartilage undergoes following burial. Fresh pig trotters were interred in 30-cm-deep graves at two distinct locations exhibiting dissimilar soil environments for up to 42 days. Extracts of the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joint cartilage from trotters disinterred weekly over 6 weeks were analyzed by Western blot against the monoclonal antibody 2-B-6 to assess aggrecan degradation. In both soil conditions, aggrecan degradation by-products of decreasing molecular size and complexity were observed up to 21 days postmortem. Degradation products were undetected after this time and coincided with MCP/MTP joint exposure to the soil environment. These results show that cartilage proteoglycans undergo an ordered molecular breakdown, the analysis of which may have forensic applications. This model may prove useful for use as a human model and for forensic investigations concerning crimes against animals and the mortality of endangered species.

To observe the age-related changes of sulfated glycosaminoglycan (sGAG) content of hip joint cartilage of elderly people based on Equilibrium Partitioning of an Ionic Contrast Agent (EPIC) micro-CT.Seventy human hip cartilage-bone samples were collected from hip-fracture patients (ages 51-96) and divided into five groups (10 years in an age group). They were first immersed in 20% concentration of the contrast agent Meglumine Diatrizoate (MD) for 6 h at 37 °C, and then scanned by micro-CT. Following scanning, samples were stained for sGAG with toluidine blue. The X-ray attenuation and sGAG optical density were calculated by image processing. The correlation between X-ray attenuation and sGAG optical density was then analyzed.The X-ray mean attenuation of the cartilage increased by 18.81% from the 50-80 age groups (p0.01), but decreased by 7.15% in the 90 age group compared to the 80 age group. The X-ray mean attenuation of the superficial layer and middle layer increased by 31.60 % and 44.68% from the 50-80 age groups, respectively (p0.01), but reduced by 4.67% and 6.05% separately in the 90 age group. However, the deep layer showed no significant change with aging. The sGAG optical density showed a linear correlation (r = -0.91, p0.01) with the X-ray attenuation.The sGAG content of hip joint cartilage varied with aging in elderly people. The changes in superficial layer and middle layer were more evident than deep layer.

To validate a fully automated scheme to extract biochemical information from the hip joint cartilages using MR T2 mapping images incorporating segmentation of co-registered three-dimensional Fast-Spin-Echo (3D-SPACE) images.Manual analyses of unilateral hip (3 Tesla) MR images of 24 asymptomatic volunteers were used to validate a 3D deformable model method for automated cartilage segmentation of SPACE scans, partitioning of the individual femoral and acetabular cartilage plates into clinically defined sub-regions and propagating these results to T2 maps to calculate region-wise T2 value statistics. Analyses were completed on a desktop computer (∼ 10 min per case).The mean voxel overlap between automated A and manual M segmentations of the cartilage volumes in the (clinically based) SPACE images was 73% (100 × 2|A∩M|/[|A|+|M|]). The automated and manual analyses demonstrated a relative difference error10% in the median "T2 average signal" for each cartilage plate. The automated and manual analyses showed consistent patterns between significant differences in T2 data across the hip cartilage sub-regions.The good agreement between the manual and automatic analyses of T2 values indicates the use of structural 3D-SPACE MR images with the proposed method provides a promising approach for automated quantitative T2 assessment of hip joint cartilages.

Background and purpose — Unloading alters the thickness of joint cartilage. It is unknown, however, to what extent unloading leads to a loss of glycosaminoglycans (GAGs) in the cartilage tissue. We hypothesized that muscle forces, in addition to axial loading, are necessary to maintain the joint cartilage GAG content of the knee and the upper and lower ankle.Patients and methods — The HEPHAISTOS orthosis was worn unilaterally by 11 men (mean age 31 (23–50) years old) for 56 days. The orthosis reduces activation and force production of the calf muscles while it permits full gravitational loading of the lower leg. MRI measurements of the knee and ankle were taken before the intervention, during the intervention (on day 49), and 14 days after the end of the intervention. Cartilage segmentation was conducted semiautomatically for the knee joint (4 segments) and for the upper (tibio-talar) and lower (subtalar) ankle joints (2 segments each). Linear mixed-effects (LME) models were used for statistical analysis....

In this chapter, we describe our renewed attempts at phalangeal regeneration by applying an osteoinductive biodegradable three-dimensional (3D) copolymer of P(LA-CL) with hydroxyapatite particles, shaped into a human phalanx. By combining a high-performance biodegradable copolymer with periosteum, we sought to achieve a better induction of phalangeal regeneration. Maintenance of joint cartilage after cartilage formation is functionally important. Periosteum has been suggested to play an important role in the regulation of joint cartilage, although the mechanism is not precisely known. An analytical study of the interaction between the periosteum and the joint cartilage in our model was undertaken. Periosteum was attached circumferentially around one half of a phalanx-molded biodegradable copolymer and the regenerative ability of bone between the periosteal and nonperiosteal sides was compared with respect to tissue-forming properties and 3D-maintained shape. Thus, our study was designed from both functional (human phalanx shape) and analytical viewpoints. A basic knowledge and understanding of the developmental processes that occur in phalangeal regeneration are clearly necessary for future clinical applications.

The shoulder (glenohumeral) joint has the greatest range of motion of all human joints; as a result, it is particularly vulnerable to dislocation and injury. The ability to non-invasively quantify in-vivo articular cartilage contact patterns of joints has been and remains a difficult biomechanics problem. As a result, little is known about normal in-vivo glenohumeral joint contact patterns or the consequences that surgery has on altering them. In addition, the effect of quantifying glenohumeral joint contact patterns by means of proximity mapping, both with and without cartilage data, is unknown. Therefore, the objectives of this study are to (1) describe a technique for quantifying in-vivo glenohumeral joint contact patterns during dynamic shoulder motion, (2) quantify normal glenohumeral joint contact patterns in the young healthy adult during scapular plane elevation depression with external humeral rotation, and (3) compare glenohumeral joint contact patterns determined both with and without articular cartilage data. Our results show that the inclusion of articular cartilage data when quantifying in-vivo glenohumeral joint contact patterns has significant effects on the anterior-posterior contact centroid location, the superior-inferior contact centroid range of travel, and the total contact path length. As a result, our technique offers an advantage over glenohumeral joint contact pattern measurement techniques that neglect articular cartilage data. Likewise, this technique may be more sensitive than traditional 6-Degree-of-Freedom (6-DOF) joint kinematics for the assessment of overall glenohumeral joint health. Lastly, for the shoulder motion tested, we found that glenohumeral joint contact was located on the anterior-inferior glenoid surface.