Degree Of Cartilage Degeneration Research Articles

High-Resolution N-Glycan MALDI Mass Spectrometry Imaging of Subchondral Bone Tissue Microarrays in Patients with Knee Osteoarthritis.

N-glycan alterations contribute to the progression of several joint diseases, including knee osteoarthritis (KOA). However, molecular changes in KOA subchondral trabecular bone, when exposed to different joint loading forces, are still unknown. The aim of this study was, therefore, to demonstrate the feasibility to differentiate N-glycan changes in subchondral trabecular bone from four different joint loading forces of the tibial plateau regions (i.e., Lateral Anterior (L-A), Lateral Posterior (L-P), Medial Anterior (M-A), and Medial Posterior (M-P)) in KOA patients (n = 10) using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) at 20 μm spatial resolution. The degree of cartilage degeneration was evaluated histologically, and the subchondral bone tissue microarrays (TMAs) were subsequently manually constructed from formalin-fixed paraffin-embedded (FFPE) KOA osteochondral (i.e., cartilage-subchondral bone) tissues. Overall, the Osteoarthritis Research Society International (OARSI) histological grade was significantly higher and the size of chondrocytes in the superficial zone was much larger for both M-A and M-P compared to L-A and L-P of cartilage (p = 0.006, p = 0.030, p = 0.028, and p = 0.010; respectively). Among the 65 putative N-glycans observed by MALDI-MSI, 2 core fucosylated bi-antennary N-glycans, m/z 1809.64; (Hex)5(HexNAc)4(Fuc)1 and 2100.73; (NeuAc)1(Hex)5(HexNAc)4(Fuc)1, were significantly higher in intensity in M-A compared to L-A of the trabecular bone (p = 0.027, and p = 0.038, respectively). These N-glycans were then further structurally characterized by in situ MS/MS fragmentation post-MALDI-MSI. Our results demonstrate, for the first time, N-glycan alterations can occur at different joint loading forces in the KOA tibial plateau and the feasibility of subchondral bone TMA construction for N-glycan MALDI-MSI.

Electroacupuncture Exerts Chondroprotective Effect in Knee Osteoarthritis of Rabbits Through the Mitophagy Pathway.

Mitochondrial dysfunction of chondrocytes has become an area of focus in Knee Osteoarthritis (KOA) in recent years. Activation of mitophagy could promote the survival of chondrocytes and alleviate cartilage degeneration. The aim of this study was to explore whether mitophagy was involved in the cartilage protection of KOA rabbits after electroacupuncture (EA) intervention. The rabbits were divided into 3 groups, Control group, KOA group, EA group, with 6 rabbits in each group. KOA model rabbits were established by modified Videman's extended immobilization method for 6 weeks and randomly divided into KOA group and EA group. The rabbits in EA group were treated every other day for 3 weeks. The degree of cartilage degeneration was detected by Safranine O-Fast Green staining and immunofluorescence. The morphological changes of chondrocytes mitochondria were detected by transmission electron microscope. ATP concentration in cartilage was measured by ATP Assay Kit. The changes of Pink1-Parkin signal pathway were detected by immunofluorescence, Western blot, and Real-time PCR. The morphology showed that EA could reduce the degeneration of KOA cartilage and increase the distribution of collagen II. We also found that EA could activate mitophagy in KOA rabbit chondrocytes to remove damaged mitochondria and restore mitochondrial homeostasis, which was manifested as increasing the expression of LC3 II/I, promoting the colocalization of TOM20 and LC3B, reducing the accumulation of mitochondrial markers outer mitochondrial membrane 20 (TOM20) and inner mitochondrial membrane 23 (TIM23), and increasing ATP production in chondrocytes. This regulation might be achieved by upregulating the Pink1-Parkin signal pathway. EA may play a role in protecting KOA cartilage by activating mitophagy mediated through Pink1-Parkin pathway.

Poster 290: Effect of Platelet-rich Plasma Injections on Cartilage T1rho in Knee Osteoarthritis

Poster 290: Effect of Platelet-rich Plasma Injections on Cartilage T1rho in Knee Osteoarthritis

Joint instability causes catabolic enzyme production in chondrocytes prior to synovial cells in novel non-invasive ACL ruptured mouse model

The Anterior Cruciate Ligament (ACL)-deficient model helps to clarify the mechanism of knee osteoarthritis (OA); however, the conventional ACL injury model could have included concurrent onset factors such as direct compression stress to cartilage and subchondral bone. In this study, we established a novel Non-invasive ACL-Ruptured mouse model without concurrent injuries and elucidated the relationship between OA progression and joint instability. We induced the ACL-Rupture non-invasively in twelve-week-old C57BL/6 male mice and evaluated histological, macroscopical, and morphological analysis at 0 days. Next, we created the ACL-R, controlled abnormal tibial translation (CATT), and Sham groups. Then, the joint stability and OA pathophysiology were analyzed at 2, 4, and 8 weeks. No intra-articular injuries, except for ACL rupture, were observed in the ACL-R model. ACL-R mice increased anterior tibial displacement compared to the Sham group (P<0.001, 95% CI [-1.509 to-0.966]) and CATT group (P<0.001, 95% CI [-0.841 to-0.298]) at 8 weeks. All mice in the ACL-R group caused cartilage degeneration. The degree of cartilage degeneration in the ACL-R group was higher than in the CATT group (P=0.006) at 8 weeks. The MMP-3-positive cell rate of chondrocytes increased in the ACL-R group than CATT group from 4 weeks (P=0.043; 95% CI [-28.32 to-0.364]) while that of synovial cells increased at 8 weeks (P=0.031; 95% CI [-23.398 to-1.021]). We successfully established a Non-invasive ACL-R model without intra-articular damage. Our model revealed that chondrocytes might react to abnormal mechanical stress prior to synovial cells while the knee OA onset.

Evaluation of articular cartilage in knee osteoarthritis using hybrid multidimensional MRI

To evaluate a two-compartment model with a normal and an abnormal compartment using hybrid multidimensional (HM) magnetic resonance imaging (MRI) for detection of early stage degeneration in knee articular cartilage. Forty mild osteoarthritis (OA; Kellgren-Lawrence grades [KLGs] 1 and 2), 27 moderate OA (KLG 3), and 23 healthy controls were included in the study. HM imaging using a two-compartment model was used to measure a normal and an abnormal cartilage compartment. The relationship between Vnormal and the degree of cartilage degeneration was examined using whole-organ MRI scores (WORMS). Receiver operating characteristic analysis was used to detect the ability of Vnormal, apparent diffusion coefficient (ADC), and T2 relaxation time to discriminate healthy controls from early OA. The intra- and interobserver reproducibility for calculated mean Vnormal values and WORMS indicated substantial agreement (intraclass correlation coefficient and weighted kappa >0.8). Overall, Vnormal in all compartments significantly differed among the healthy controls (50±5.5%) and mild (41.1±5.3%) and moderate OA (36.4±8.1%). Mean Vnormal correlated negatively with the degree of OA progression (ρ=-0.778, p<0.001). Mean Vnormal was characterised by a higher sensitivity (82.5%, 95% confidence interval [CI=67.2-92.7) and specificity (87%, 95% CI=66.4-97.2), with a cut-off value of 44.4%, compared to ADC and T2 values or a combination of ADC and T2 to differentiate early OA from healthy controls. HM-MRI coupled with values of ADC and T2 may provide value for detecting cartilage degeneration at an early stage of OA.

Arthroscopic Debridement, Facetectomy, and Synovectomy for Isolated Patellofemoral Osteoarthritis

Isolated patellofemoral osteoarthritis (PFOA) is a condition that affects climbing, squatting, and standing up movements in daily life and sports. Various surgical methods have been developed to address the various causes, different degrees of cartilage degeneration, and combined lesions. We describe an arthroscopic patellofemoral arthroplasty technique, with the main purpose to decrease the pain originating from the patellofemoral joint and related structures. The critical points of this technique are patellofemoral denervation and partial patellar facetectomy. Our clinical experience indicates that this technique is effective to address all kinds of PFOA. We consider that the introduction of this technique will provide a feasible choice when surgical treatment of PFOA is indicated.

Expression and Localization of Thrombospondins, Plastin 3, and STIM1 in Different Cartilage Compartments of the Osteoarthritic Varus Knee.

Osteoarthritis (OA) is a multifactorial disease which is characterized by a change in the homeostasis of the extracellular matrix (ECM). The ECM is essential for the function of the articular cartilage and plays an important role in cartilage mechanotransduction. To provide a better understanding of the interaction between the ECM and the actin cytoskeleton, we investigated the localization and expression of the Ca2+-dependent proteins cartilage oligomeric matrix protein (COMP), thrombospondin-1 (TSP-1), plastin 3 (PLS3) and stromal interaction molecule 1 (STIM1). We investigated 16 patients who suffered from varus knee OA and performed a topographical analysis of the cartilage from the medial and lateral compartment of the proximal tibial plateau. In a varus knee, OA is more pronounced in the medial compared to the lateral compartment as a result of an overloading due to the malalignment. We detected a location-dependent staining of PLS3 and STIM1 in the articular cartilage tissue. The staining intensity for both proteins correlated with the degree of cartilage degeneration. The staining intensity of TSP-1 was clearly reduced in the cartilage of the more affected medial compartment, an observation that was confirmed in cartilage extracts by immunoblotting. The total amount of COMP was unchanged; however, slight changes were detected in the localization of the protein. Our results provide novel information on alterations in OA cartilage suggesting that Ca2+-dependent mechanotransduction between the ECM and the actin cytoskeleton might play an essential role in the pathomechanism of OA.

Clinical and Pathological Features in Horses With Advanced Arytenoid Chondritis.

Equine arytenoid chondritis causes airway obstruction and abnormal upper airway noise due to a space-occupying lesion(s) and decreased abduction. Our objective was to compare clinical scores and ultrasonographic findings with gross and microscopic lesions of naturally occurring arytenoid chondritis, in order to guide surgical treatment. Seventeen naturally affected horses with advanced/severe chronic arytenoid chondritis and 4 control arytenoid cartilages were evaluated after partial arytenoidectomy. Cartilages were sectioned caudal to the corniculate process and the body of each arytenoid was measured. We assessed total gross area (TA), percentage of viable cartilage (VC), percentage of viable cartilage on the lateral wall, and medial expansion. Retrospectively, the gross lesions were used to suggest 2 preferred surgical management (SM) groups: those requiring partial arytenoidectomy and those amendable to focal medial resection (a conservative SM). TA of horses with arytenoid chondritis was significantly larger than controls (P = .005), due to a layered lesion composed of cavitation, granulation tissue, fibrosis, inflammation, hemorrhage, and edema, with relatively equal medial and lateral expansion that distorted the geometry of the affected cartilage. The increased TA paralleled the presence of immature cartilage with disorganized primitive mesenchymal cells. TA and SM were positively correlated (P = .01). All cases showed varying degrees of cartilage degeneration or necrosis, more severe medially; those appearing amenable to focal medial resection arytenoid group had significantly more viable cartilage on the lateral wall (P = .02). The gross and histopathologic findings suggest a new surgical approach-focal medial resection-that may save the lateral wall of the arytenoid.

Discoid lateral meniscus: a simple horizontal tear was associated with less articular cartilage degeneration compared to other types of tear.

The relationship between the tear type of discoid lateral meniscus (DLM) and articular cartilage degeneration has not been well studied. Data from patients with DLM tears who underwent arthroscopic surgery, between 2008 and 2016, were reviewed retrospectively. Demographic variables were obtained from medical records. The types of DLM and meniscal tear and status of cartilage were assessed using operation records and arthroscopic images. Patients were assigned to horizontal or non-horizontal tear groups according to the types of the tear. Factors affecting cartilage degeneration of the lateral femoral condyle (LFC) and lateral tibial plateau (LTP) were identified using logistic regression analysis. The horizontal tear group was divided into two subgroups on the basis of the median value of duration of symptoms and difference in cartilage degeneration between the two subgroups was evaluated. Overall, 355 knees were enrolled and assigned to the horizontal (n = 53) or the non-horizontal (n = 302) tear groups. The incidence of International Cartilage Repair Society grades 2-4 cartilage lesions of the LFC (0%, P < 0.001) and LTP (24.5%, P < 0.001) was significantly lower in the horizontal tear group than in the non-horizontal tear group. Horizontal tear [LFC, odds ratio (OR) = 0.02, P < 0.001; LTP, OR = 0.27, P < 0.001] and age (LFC, OR = 1.04, P < 0.001; LTP, OR = 1.03, P < 0.001) were significantly related to cartilage status. There was no difference in cartilage degeneration between the two subgroups in the horizontal tear group. A simple horizontal tear was associated with less articular cartilage degeneration compared to other types of tear in the DLM. In the case of simple horizontal tear, there was no difference in the degree of cartilage degeneration according to the duration of symptoms. Therefore, it is not necessary to perform surgical treatment promptly in cases of simple horizontal tears unless the patient's symptoms are severe. III, Case-Control Study.

Quantitative susceptibility mapping of articular cartilage in patients with osteoarthritis at 3T.

Quantitative susceptibility mapping (QSM) has recently been applied in humans to quantify the magnetic susceptibility of collagen fibrils in the articular cartilage. To determine the ability of QSM to detect cartilage matrix degeneration between normal and early knee osteoarthritis (OA) patients. Prospective. Twenty-four patients with knee OA and 24 age- and sex-matched healthy controls. 3D gradient echo, T1 turbo spin echo, and proton density-weighted (PDw) spectral attenuated inversion recovery (SPAIR) sequence at 3.0T. Scan-rescan reproducibility of the susceptibility values in the cartilage was assessed in control subjects. Cartilage thickness, volume, mean, and standard deviation (SD) of susceptibility values of the cartilage compartments were compared between normal and OA patients. The relationship between magnetic susceptibility values and cartilage lesion grading based on MR images was studied. The Wilcoxon Rank-Sum test was used to compare cartilage thickness, volume, mean, and SD of susceptibility values between control subjects and OA patients. A Spearman rank correlation was performed to study the relationship between the mean and SD of susceptibility values and the cartilage thinning grades. The SD of magnetic susceptibility values in the knee cartilage was significantly lower in OA patients compared with healthy controls, and it decreased with more severe MR grades of cartilage thinning degeneration. Significant correlations between the SD of susceptibility values and cartilage thinning grades were observed with R2 = 0.64 and P = 0.000, R2 = 0.47 and P = 0.002, R2 = 0.52 and P = 0.001, R2 = 0.42 and P = 0.0006, and R2 = 0.67 and P = 0.000 for medial femoral condyle (MFC), lateral femoral condyle (LFC), medial tibia (MT), lateral tibia (LT), and patella, respectively. No significant difference was found in cartilage volume (P = 0.17, P = 0.13, P = 0.20, P = 0.25, and P = 0.18 for MFC, LFC, MT, LT, and patella, respectively) and thickness (P = 0.31, P = 0.19, P = 0.16, P = 0.09, and P = 0.22 for MFC, LFC, MT, LT, and patella, respectively) between OA patients and healthy controls. The variations of susceptibility values in the knee cartilage decrease with the degree of cartilage degeneration. QSM may be a sensitive indicator for alteration of the collagen network and shows potential to detect cartilage degeneration at early stage. 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018.

Varus knee osteoarthritis: Elevated synovial CD15 counts correlate with inferior biomechanical properties of lateral-compartment cartilage.

The study analyzed the influence of synovitis on the histological and biomechanical properties of lateral-compartment cartilage. In a prospective cohort study, 84 patients (100 knees) with varus deformity of the knee were included. Osteochondral samples from the distal lateral femur underwent biomechanical and histologic analysis. Synovial tissue was sampled for histological (chronic synovitis score) and immunohistochemical evaluation of the degree of synovitis. CD15 (neutrophils), Ki-67 (dividing cells), and CD68 (macrophages) were tested in all synovial samples. While the histological synovitis score did not correlate with the degree of cartilage degeneration (histological OARSI grades), both CD15 (rs = 0.297, p = 0.006) and Ki-67 (rs = 0.249, p = 0.023) correlated with histological OARSI grades. There was a weak negative correlation of CD15 with biomechanical properties of cartilage of the distal lateral femur (aggregate modulus (Ha): rs = -0.125; p = 0.257; dynamic modulus (DM): rs = -0.216; p = 0.048). No correlations were observed for Ki-67 and CD68. In addition, biomechanical properties were inferior in knees with a CD15 of >8/high power field compared to knees with a CD15 of ≤8/high power field (Ha: p = 0.031, d = 0.46; DM: p = 0.005, d = 0.68). The study demonstrates an association of increased inflammatory activity with advanced cartilage degeneration. Lateral-compartment cartilage in knees with elevated synovial CD15 counts has a reduced ability to withstand compressive loads. CD15 might serve as an indicator for inferior biomechanical cartilage properties. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:841-846, 2018.

Fibronectin splice variation in human knee cartilage, meniscus and synovial membrane: observations in osteoarthritic knee.

Fibronectin (FN) is a widely expressed molecule that can participate in development of osteoarthritis (OA) affecting cartilage, meniscus, and synovial membrane (SM). The alternatively spliced isoforms of FN in joint tissues other than cartilage have not been extensively studied previously. The present study compares FN splice variation in patients with varying degrees of osteoarthritic change. Joint tissues were collected from asymptomatic donors and patients undergoing arthroscopic procedures. Total RNA was amplified by PCR using primers flanking alternatively spliced Extra Domain A (EDA), Extra Domain B (EDB) and Variable (V) regions. EDB(+) , EDB(-) and EDA(-) and V(+) variants were present in all joint tissues, while the EDA(+) variant was rarely detected. Expression levels of EDB(+) and EDV(+) variants were similar in cartilage, synovium, and meniscal tissues. Synovial expression of V(+) FN in arthroscopy patients varied with degree of cartilage degeneration. Two V(-) isoforms, previously identified in cartilage, were also present in SM and meniscus. Fibronectin splicing in meniscus and SM bears striking resemblance to that of cartilage. Expression levels of synovial V(+) FN varied with degree of cartilage degeneration. V(+) FN should be investigated as a potential biomarker of disease stage or progression in larger populations.

The DNA repair enzyme apurinic/apyrimidinic endonuclease (Apex nuclease) 2 has the potential to protect against down-regulation of chondrocyte activity in osteoarthritis.

Apurinic/apyrimidinic endonuclease 2 (Apex 2) plays a critical role in DNA repair caused by oxidative damage in a variety of human somatic cells. We speculated that chondrocyte Apex 2 may protect against the catabolic process of articular cartilage in osteoarthritis (OA). Higher levels of Apex 2 expression were histologically observed in severely compared with mildly degenerated OA cartilage from STR/OrtCrlj mice, an experimental model which spontaneously develops OA. The immunopositivity of Apex 2 was significantly correlated with the degree of cartilage degeneration. Moreover, the OA-related catabolic factor interleukin-1β induced the expression of Apex 2 in chondrocytes, while Apex 2 silencing using small interfering RNA reduced chondrocyte activity in vitro. The expression of Apex 2 in chondrocytes therefore appears to be associated with the degeneration of articular cartilage and could be induced by an OA-related catabolic factor to protect against the catabolic process of articular cartilage. Our findings suggest that Apex 2 may have the potential to prevent the catabolic stress-mediated down-regulation of chondrocyte activity in OA.

Effects of Platelet Rich Plasma (PRP) in Treatment of Experimentally Induced Osteoarthritis in Rabbit’s Knee Joint

Osteoarthritis is the most common type of arthritis and the major cause of chronic disability in musculoskeletal mobility in the elderly populations worldwide. In this study, the scaffold free autologous platelet rich plasma (PRP) in an experimental animal model of osteoarthritis (OA) by direct intra articular injection was used. Seventeen New Zealand white adult rabbits of both sexes were used. Osteoarthritis was induced by anterior cruciate ligament transection of knee joints. Eight weeks following operation, a single dose of (0.5 ml) Platelet Rich plasma (PRP) was delivered into the injured knee by direct intra articular injection. The control group received no treatment. The knees were examined on 12 and 16 weeks past from the initial operation. The healing status was investigated histopathologically. Pathologic assessment confirmed development of OA changes after 8 weeks which was advanced at 12 weeks in the control group. PRP treated Rabbits showed lower degree of cartilage degeneration, less osteophyte formation, and minimal subchondral sclerosis at 12 weeks following surgery compared to the control group. The PRP group had near to normal joint structure at 16 week postoperative interval. This study showed that the PRP could potentially be used for the treatment of osteoarthritis.

Alterations in the chondroitin sulfate chain in human osteoarthritic cartilage of the knee

To determine whether the structure of chondroitin sulfate (CS) in cartilage is reflected by the degree of cartilage degeneration in patients with osteoarthritis (OA) of the knee and to determine how CS biosynthesis affects cartilage degeneration. Two osteoarthritic cartilage samples were obtained from medial femoral condyle (MFC) and lateral femoral condyle (LFC) of 24 knees with end-stage OA. The samples were assigned to two groups as follows: lesion and remote cartilage were adjacent to and remote from the osteoarthritic cartilage, respectively. Histological grade was determined according to the Mankin score. The CS concentration and chain length were determined using high-performance liquid chromatography (HPLC) and gel filtration chromatography, respectively. Expression of the gene encoding CS glycosyltransferase was evaluated using a real-time quantitative polymerase chain reaction (qPCR) assay. These results were compared between lesion and remote cartilage. The Mankin score indicated that lesion cartilage was more degraded compared with remote cartilage. Although the CS levels varied among individuals, the mean CS concentration and chain length were significantly lower and shorter in lesion cartilage than in remote cartilage, respectively (concentration: 12.04 vs 14.84 μg/mg wet weight, P = 0.021; chain length: 5.36 vs 6.19 kDa, P = 0.026). Three genes encoding CS glycosyltransferases (CHPF, CSGALNACT1, CSGALNACT2) were expressed at lower levels in lesion cartilage. In the osteoarthritic knee, the CS concentration and chain length were reduced closer to the more degraded cartilage with decreasing CS glycosyltransferase gene expression. Inhibition of CS glycosyltransferase gene expression may reduce CS chain length, which may contribute to OA progression.

Osteoarthritis of the patella, lateral femoral condyle and posterior medial femoral condyle correlate with range of motion

The type of osteoarthritis and the degree of severity which causes restriction of knee range of motion (ROM) is still largely unknown. The objective of this study was to analyse the location and the degree of cartilage degeneration that affect knee range of motion and the connection, if any, between femorotibial angle (FTA) and knee ROM restriction. Four hundreds and fifty-six knees in 230 subjects with knee osteoarthritis undergoing knee arthroplasty were included. Articular surface was divided into eight sections, and cartilage degeneration was evaluated macroscopically during the operation. Cartilage degeneration was classified into four grades based on the degree of exposure of subchondral bone. A Pearson correlation was conducted between FTA and knee flexion angle to determine whether high a degree of FTA caused knee flexion restriction. A logistic regression analysis was also conducted to detect the locations and levels of cartilage degeneration causing knee flexion restriction. No correlation was found between FTA and flexion angle (r = -0.08). Flexion angle was not restricted with increasing FTA. Logistic regression analysis showed significant correlation between restricted knee ROM and levels of knee cartilage degeneration in the patella (odds ratio (OR) = 1.77; P = 0.01), the lateral femoral condyle (OR = 1.62; P = 0.03) and the posterior medial femoral condyle (OR = 1.80; P = 0.03). For clinical relevance, soft tissue release and osteophyte resection around the patella, lateral femoral condyle and posterior medial femoral condyle might be indicated to obtain a higher degree of knee flexion angle.

Cartilage degeneration and not age influences the health-related quality of life outcome after partial meniscectomy

The purpose of this study is to investigate whether inconsistently reported factors influence the health-related quality of life (HRQOL) outcome of partial meniscectomy. Short Form 36 (SF-36) data on 216 patients were retrospectively analysed for the influence of the factors age, gender and degree of cartilage degeneration. Mixed linear models were applied for univariate and multivariate analyses. All SF-36 scales, including the psychosocial scales, showed a significant improvement from pre- to post-operative (p<0.001). The factor 'degree of cartilage degeneration' was found to significantly influence post-surgical improvement of the SF-36 'physical component summary' score. Patients with mild cartilage degeneration benefited significantly more from surgery than did patients with advanced cartilage degeneration (p=0.011). Older patients had significantly lower scores on each subscale, but showed no significant age-time interaction, that is, no association was seen between age and the degree of improvement. No effect was determined for the variable gender. The findings of the current study can be interpreted to show that arthroscopic partial meniscectomy significantly improves HRQOL, even in mental or psychosocial dimensions of HRQOL. Not age but the degree of cartilage degeneration influences the HRQOL gain that can be expected. The factor gender has no effect on HRQOL. The findings of our study influence our daily routine, in that we take the degree of cartilage degeneration and not age as predictive value for the success to be anticipated from the procedure. Concerning the preoperative consenting, it is important to mention that advanced cartilage degeneration is a predictor of a less favourable outcome. IV.

T1ρ and T2 mapping reveal the in vivo extracellular matrix of articular cartilage

To determine the relationship between changes in the extracellular matrix (ECM) and T(1ρ) and T(2) values in vivo. The ECM is composed of proteoglycan (PG), collagen, and water. It has been unclear which of the ECM constituents affects T(1ρ) and T(2) mapping in living human cartilage. Sagittal T(1ρ) and T(2) maps were preoperatively obtained from 20 knee osteoarthritis patients. Osteochondral samples harvested from the resected tibial plateaus during total knee arthroplasty were consistent with the MRIs of the patients' knees. Parameters that included histological grading of cartilage degeneration, glycosaminoglycan (GAG) content (which constitutes PG), presence of collagen anisotropy and water content were evaluated along with T(1ρ) and T(2) values, and statistical analysis was performed using multiple regression analysis. T(1ρ) and T(2) values were significantly correlated with the degree of cartilage degeneration (β = 0.397 and 0.357, respectively) and the GAG content (β = -0.340 and -0.244, respectively). The present study demonstrated that T(1ρ) and T(2) values reflect the GAG content of the cartilage and can indicate cartilage degeneration in vivo. Use of these parameters can facilitate the noninvasive diagnosis and evaluation of cartilage degeneration.

Knee-to-Ankle Mosaicplasty for the Treatment of Osteochondral Lesions of the Ankle Joint

Background Osteochondral lesions are frequently seen in athletes after ankle injuries. At this time, osteochondral autologous transplantation (OATS, mosaicplasty) is the only surgical treatment that replaces the entire osteochondral unit in symptomatic lesions. Purpose To evaluate the clinical and radiological midterm to long-term outcome of ankles treated with knee-to-ankle mosaicplasty. Study Design Case series; Level of evidence, 4. Methods Clinical evaluation consisted of patient satisfaction, pain evaluation (visual analog scale [VAS]), American Orthopaedic Foot and Ankle Society (AOFAS) ankle score, sports activity score, range of motion, the radiological evaluation of magnetic resonance imaging (MRI), and single photon emission computed tomography–computed tomography (SPECT-CT) analysis of both the ankle and the knee joint. Results Twelve of 21 patients (mean age, 43 years; male, 8; female, 4) were available for latest follow-up (mean, 72 months). At follow-up, patients reported a satisfaction rate of good to excellent in 92% (n 5 11) and poor in 8% (n 5 1). The average VAS pain score was 3.9 (preoperative, 5.9; P 5 .02), AOFAS ankle score significantly increased from 45.9 to 80.2 points (P< .0001), sports activity score remained significantly decreased with 1.25 (preinjury level, 2.3; P 5 .035), and ankle dorsiflexion was significantly reduced (P 5 .003). Knee pain was reported in 6 patients (50%). Radiologically, recurrent lesions were found in 10 of 10 cases (100%) and some degree of cartilage degeneration and discontinuity of the subchondral bone plate in 100%. Conclusion Indications for mosaicplasty with a plug transfer from the knee to the talus must be considered carefully, as at midterm, moderate outcome and considerable donor-site morbidity may be found.

Rapid isotropic 3D‐sodium MRI of the knee joint in vivo at 7T

To demonstrate the feasibility of acquiring high-resolution, isotropic 3D-sodium magnetic resonance (MR) images of the whole knee joint in vivo at ultrahigh field strength (7.0T) via a 3D-radial acquisition with ultrashort echo times and clinically acceptable acquisition times. Five healthy controls (four males, one female; mean +/- standard deviation [SD] age 28.7 +/- 4.8 years) and five patients with osteoarthritis (OA) (three males, two females; mean +/- SD age 52.4 +/- 5.6 years) underwent (23)Na MRI on a 7T, multinuclei equipped whole-body scanner. A quadrature (23)Na knee coil and a 3D-gradient echo (GRE) imaging sequence with a radial acquisition were utilized. Cartilage sodium concentration was measured and compared between the healthy controls and OA patients. The average signal-to-noise ratio (SNR) for different spatial resolutions (1.2-4 mm) varied from approximately 14-120, respectively. The mean sodium concentration of healthy subjects ranged from approximately 240 +/- 28 mM/L to 280 +/- 22 mM/L. However, in OA patients the sodium concentrations were reduced significantly by approximately 30%-60%, depending on the degree of cartilage degeneration. The preliminary results suggest that sodium imaging at 7T may be a feasible potential alternative for physiologic OA imaging and clinical diagnosis.