OBJECTIVE: Loose bodies are free-floating tissues of cartilage and bone that can cause pain, swelling, the inability to straighten the knee, or intermittent locking of the knee. Loose bodies can arise from degenerative j...OBJECTIVE: Loose bodies are free-floating tissues of cartilage and bone that can cause pain, swelling, the inability to straighten the knee, or intermittent locking of the knee. Loose bodies can arise from degenerative joint disease, flake fractures, osteochondritis dissecans, or chondromatosis. We hypothesized that loose bodies can be classified in stages with tissue characteristics similar to endochondral ossification. DESIGN: Loose bodies were harvested from patients undergoing joint replacement. Samples were processed for histology, gene expression analysis, and micro-computed tomography (µCT). Cartilage- and bone-related genes and proteins were selected for immunofluorescence stainings (collagen type I, II, and X, SOX9 [SRY-box transcription factor 9], and MMP13 [matrix metalloproteinase 13]) and gene expression analysis ( [fibronectin], , and aggrecan []). RESULTS: Loose bodies were grouped in 4 stages: fibrous, (mineralized) cartilaginous, cartilage and bone, and bone. Hyaline-like cartilage tissue with Benninghoff arcades was present in stages 2 and 3. A transition from cartilaginous to mineralized tissue and bone trabecula was defined by an increase in and (stage 3 vs. 4: = 0.047) positive area. Stage 4 showed typical trabecular bone tissue. The relative volume of calcified tissue (mineralized cartilage and bone tissue) decreased with stages (stages 1-2 vs. 3: = 0.002; stage 1-2 vs. 4: = 0.012). expression and stained area decreased from stages 1-2 to 4 ( = 0.010 and = 0.004). expression decreased from stage 1-2 to stage 3 ( = 0.049) and stage 4 ( = 0.002). CONCLUSION: Loose bodies show tissue characteristics similar to endochondral ossification. They are probably a relevant substrate for regenerative therapeutic interventions in joint disease.
OBJECTIVE: In contrast to osteochondral lesion (OCL) of the ankle, OCLs in other joints of the foot, such as subtalar joint, talonavicular joint, calcaneocuboid joint, and the midfoot, are rare conditions, but they can a...OBJECTIVE: In contrast to osteochondral lesion (OCL) of the ankle, OCLs in other joints of the foot, such as subtalar joint, talonavicular joint, calcaneocuboid joint, and the midfoot, are rare conditions, but they can also lead to significant morbidity. The objective of this systematic review was to summarize the clinical evidence for the treatment of OCLs of the subtalar, talonavicular, calcaneocuboid, and the other midfoot joints. DESIGN: A systematic search of the MEDLINE, EMBASE, and Cochrane Library databases was performed in January 2021 based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by 2 independent reviewers. Included studies were evaluated with regard to LOE (level of evidence) and QOE (quality of evidence). Variable reporting outcome data, clinical outcomes, and complications were evaluated. RESULTS: Seventeen studies with 21 patients were included, all of which were case reports (level 5) without any case series reporting greater than 3 patients. There were 5 patients with OCL in the subtalar joint, 15 patients in the talonavicular joint, and 1 patient in the calcaneocuboid joint. Thirteen case reports (4 subtalar joint, 8 talonavicular joint, and 1 calcaneocuboid joint) reported surgical treatment. Surgical procedures mainly included debridement, bone marrow stimulation, fixation, and bone grafting, through open or arthroscopy, all of which resulted in successful outcomes. Four case reports (1 subtalar joint, 3 talonavicular joint) reported successful conservative treatment. Other 13 case reports reported successful surgery after failed conservative treatment. No complications and reoperations were reported. CONCLUSIONS: The current systematic review revealed that there is no available evidence to ascertain clinical outcomes of both conservative and surgical treatments for cartilage lesions in the talonavicular joint, subtalar joint, and the midfoot joints, owing to the extreme paucity of literature. Both nonoperative and operative treatments can be considered, but no treatment strategies have been established.
ObjectiveThe use of porcine animal models for cartilage injury has increased recently due to their similarity with humans with regard to cartilage thickness, limited intrinsic healing of chondral defects, and joint loadi...ObjectiveThe use of porcine animal models for cartilage injury has increased recently due to their similarity with humans with regard to cartilage thickness, limited intrinsic healing of chondral defects, and joint loading biomechanics. However, variations in the mechanical and biochemical properties of porcine hip articular cartilage among various tissue ages and weightbearing (WB) regions are still unknown. This study's aim was to characterize the mechanical and biochemical properties of porcine hip articular cartilage across various ages and WB regions.MethodsArticular cartilage explants were harvested from WB and non-weightbearing (NWB) surfaces of the femoral head and acetabulum of domesticated pigs () at fetal (gestational age: 80 days), juvenile (6 months), and adult (2 years) ages. Explants underwent compressive stress-relaxation mechanical testing, biochemical analysis for total collagen and glycosaminoglycan (GAG) content, and histological staining.ResultsJuvenile animals consistently had the highest mechanical properties, with 2.2- to 7.6-time increases in relaxation modulus, 1.3- to 2.3-time increases in instantaneous modulus, and 4.1- to 14.2-time increases in viscosity compared with fetal cartilage. Mechanical properties did not significantly differ between the WB and NWB regions. Collagen content was highest in the NWB regions of the juvenile acetabulum (65.3%/dry weight [DW]) and femoral head (75.4%/DW) cartilages. GAG content was highest in the WB region of the juvenile acetabulum (23.7%/DW) and the WB region of the fetal femoral head (27.5%/DW) cartilages. Histological staining for GAG and total collagen content followed the trends from the quantitative biochemical assays.ConclusionThis study provides a benchmark for the development and validation of preclinical porcine models for hip cartilage pathologies.
ObjectiveMicroRNAs (miRNAs) play a key role in the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) into chondrocytes. Our previous study found that novel-miR-81 can relieve osteoarthritis, but its r...ObjectiveMicroRNAs (miRNAs) play a key role in the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) into chondrocytes. Our previous study found that novel-miR-81 can relieve osteoarthritis, but its role in chondrogenic differentiation of BMSCs remains unclear. The purpose of this study was to explore the role of novel-miR-81 in chondrogenic differentiation of BMSCs.MethodsWe used a model in which transforming growth factor (TGF)-β3-induced BMSCs differentiation into chondrocytes. We detected the expression Sox9, Collagen Ⅱ, Aggrecan, novel-miR-81, and Rac2 by real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Western blot was performed to detect the expression of Sox9, Collagen Ⅱ, and Rac2. Dual-luciferase reporter gene assay confirmed that the association between novel-miR-81 and Rac2. In addition, the ectopic chondrocyte differentiation of BMSCs was performed subcutaneously in nude mice. The effect of novel-miR-81 and Rac2 on ectopic chondrogenic differentiation of BMSCs was determined by immunohistochemical staining.ResultsNovel-miR-81 upregulated in chondrogenic differentiation of BMSCs. Rac2 was a key target of novel-miR-81. Mimic novel-miR-81 and siRac2 upregulated the expression of Sox9, Collagen Ⅱ, and Aggrecan.ConclusionNovel-miR-81 promotes the chondrocytes differentiation of BMSCs by inhibiting the expression of target gene Rac2, which provides potential targets for BMSCs transplantation to repair cartilage defects.
ObjectiveOur study was performed to investigate whether micro-223 promotes diabetic Osteoarthritis (OA) progression by regulating cartilage degeneration and subchondral bone remodeling.MethodsThe expression of miR-223 in...ObjectiveOur study was performed to investigate whether micro-223 promotes diabetic Osteoarthritis (OA) progression by regulating cartilage degeneration and subchondral bone remodeling.MethodsThe expression of miR-223 in human normal cartilage, OA cartilage, and subchondral bone tissue with or without DM was detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). miR-223 mimic or inhibitor was transfected into chondrocytes. Cell viability and apoptosis were assessed by 3-(4,5)-dimethylthiahiazo(-2)-3,5-diphenyltetrazolium bromide (MTT) and Terminal Deoxynucleotidyl Transferase(TdT)-mediated dUTP nick end labeling (TUNEL) assay, respectively.ResultsmiR-223 was significantly higher in human diabetic OA cartilage and subchondral bone compared with normal OA and healthy control. Overexpression of miR-223 accelerated cartilage degeneration and subchondral bone sclerosis in diabetic OA mice, whereas miR-223 inhibition had the opposite effect. upregulation of miR-223 decreased proliferation and enhanced apoptosis of chondrocytes. Meanwhile, downregulation of miR-223 promoted glycosaminoglycan (GAG) production in chondrocytes.ConclusionmiR-223 promotes diabetic OA progression by regulating cartilage degeneration and subchondral bone remodeling both and .
ObjectiveIntegrin α10β1-selected mesenchymal stem cells (integrin α10-MSCs) have previously shown potential in treating cartilage damage and osteoarthritis (OA) and in animal models . The aim of this study was to furthe...ObjectiveIntegrin α10β1-selected mesenchymal stem cells (integrin α10-MSCs) have previously shown potential in treating cartilage damage and osteoarthritis (OA) and in animal models . The aim of this study was to further investigate disease-modifying effects of integrin α10-MSCs.DesignOA was surgically induced in 17 horses. Eighteen days after surgery, horses received 2 × 10 integrin α10-MSCs intra-articularly or were left untreated. Lameness and response to carpal flexion was assessed weekly along with synovial fluid (SF) analysis. On day 52 after treatment, horses were euthanized, and carpi were evaluated by computed tomography (CT), MRI, histology, and for macroscopic pathology and integrin α10-MSCs were traced in the joint tissues.ResultsLameness and response to carpal flexion significantly improved over time following integrin α10-MSC treatment. Treated horses had milder macroscopic cartilage pathology and lower cartilage histology scores than the untreated group. Prostaglandin E2 and interleukin-10 increased in the SF after integrin α10-MSC injection. Integrin α10-MSCs were found in SF from treated horses up to day 17 after treatment, and in the articular cartilage and subchondral bone from 5 of 8 treated horses after euthanasia at 52 days after treatment. The integrin α10-MSC injection did not cause joint flare.ConclusionThis study demonstrates that intra-articular (IA) injection of integrin α10-MSCs appears to be safe, alleviate pathological changes in the joint, and improve joint function in an equine post-traumatic osteoarthritis (PTOA) model. The results suggest that integrin α10-MSCs hold promise as a disease-modifying osteoarthritis drug (DMOAD).
ObjectiveAlthough knee osteoarthritis (KOA) is a common disease, there is a lack of specific prevention and early treatment methods. Hence, this study aimed to examine the molecular changes occurring at different stages...ObjectiveAlthough knee osteoarthritis (KOA) is a common disease, there is a lack of specific prevention and early treatment methods. Hence, this study aimed to examine the molecular changes occurring at different stages of KOA to elucidate the dynamic nature of the disease.DesignUsing a low-force compression model and analyzing RNA sequencing data, we identified molecular changes in the transcriptome of knee joint cartilage, including gene expression and molecular pathways, between the cellular changes and structural damage stages of KOA progression. In addition, we validated hub genes using an external dataset.ResultsGene set enrichment analysis (GSEA) identified the following pathways to be associated with KOA: "B-cell receptor signaling pathway," "cytokine-cytokine receptor interaction," and "hematopoietic cell lineage." Expression analysis revealed 585 differentially expressed genes, with 579 downregulated and 6 upregulated genes. Enrichment and clustering analyses revealed that the main molecular clusters were involved in cell cycle regulation and immune responses. Furthermore, the hub genes , and were related to immune responses.ConclusionsOur study provides insights into the dynamic nature of early-stage KOA and offers valuable information to support the development of effective intervention strategies to prevent the irreversible damage associated with KOA, thereby addressing a major clinical challenge.
Intra-articular injections of hyaluronic acid (HA) are widely used in the treatment of osteoarthritis. HA half-life varies between products which might explain differences in effectiveness between viscosupplements.AimTo...Intra-articular injections of hyaluronic acid (HA) are widely used in the treatment of osteoarthritis. HA half-life varies between products which might explain differences in effectiveness between viscosupplements.AimTo compare the resistance to degradation of linear and cross-linked viscosupplements using a rheological model combining mechanical and oxidative stresses, mimicking what happens inside the joint following HA injection.MethodsThe rheological properties of 8 HAs were measured using a stress-imposed Rheometer DHR3. Strain sweeps were carried out to evaluate the rheological properties at rest from 0.001 to 3000% at a frequency of 1 Hz. The complex modulus G*, in Pa, and the phase tangent tan δ, dimensionless, in the linear viscoelastic domain (LVED) were extracted. The oxidation tests were conducted by exposing the product to HO for 30 minutes. The effect of oxidation was evaluated by measuring variations of G* and tan δ, using an oscillation time sweep. Those tests were carried out at a frequency of 1 Hz and at 1% strain in the LVED.ResultsAt rest, the different samples exhibited various viscous behaviors. During mixing process, G* decreased from -6.4% to -31.3%. G* of low-molecular-weight HAs decreased more than that of medium molecular weight (MW) and cross-linked products. After oxidative stress, G* variation ranged from -10.1% to -46.3%. Cross-linked HAs and those containing mannitol resisted the best to degradation.ConclusionsWe showed large variations in resistance to degradation between viscosupplements. The duration of effectiveness of these products deserves to be compared in randomized clinical studies.
OBJECTIVE: To collate current literature pertaining to the published reports of indications for, and outcomes of, osteochondral allograft (OCA) transplantations in the shoulder so as to guide surgeons in the management o...OBJECTIVE: To collate current literature pertaining to the published reports of indications for, and outcomes of, osteochondral allograft (OCA) transplantations in the shoulder so as to guide surgeons in the management of various etiologies of osteochondral lesions in this joint. DESIGN: A systematic review of the current literature was performed in February 2022 in the PubMed, Cochrane, and EMBASE databases using specific search terms and predetermined inclusion/exclusion criteria. RESULTS: One-hundred-twenty-three articles were initially identified, 30 full-text articles were assessed for eligibility, and 17 articles met inclusion criteria. Data were collected for study characteristics, etiology, lesion size/location, intervention/type of graft used, follow-up, and outcomes. In total, 83 shoulders were included ( = 83) in the review with an average follow-up of 45.7 months. Nine specific indications for OCA transplantation in the shoulder included: reverse Hill-Sachs lesions (33), Hill-Sachs lesions (22), pain pump chondrolysis (10), recurrent shoulder instability (7), osteoarthritis/degenerative changes (5), radiofrequency chondrolysis (2), prominent suture anchors (2), glenoid lesion (1), and osteochondritis dissecans (1). Seventeen patients had concomitant surgeries and two patients were lost to follow-up. Of the total 83 shoulders, 68 had favorable outcomes and 13 had unfavorable outcomes as determined by graft incorporation, pain scores, functionality/ROM, patient-reported satisfaction, and/or requirement for revision/arthroplasty. Of the 13 with unfavorable outcomes, a disproportionate number had concomitant surgeries and/or were performed for pain pump chondrolysis (6). CONCLUSIONS: The use of OCAs appears to be a viable option for a variety of difficult-to-treat shoulder pathologies, particularly those characterized by isolated osteochondral injuries.
OBJECTIVE: To determine the clinical, safety, and radiological outcomes after biological resurfacing arthroplasty for the treatment of osteoarthritis (OA) of one or more joints of the midtarsal joint complex. DESIGN: All...OBJECTIVE: To determine the clinical, safety, and radiological outcomes after biological resurfacing arthroplasty for the treatment of osteoarthritis (OA) of one or more joints of the midtarsal joint complex. DESIGN: All prospectively followed patients with OA to one of or multiple joints of the midtarsal joint complex who were operated with a biological resurfacing arthroplasty with a fascia lata autograft (BioJoint procedure) were included. A total of 7 patients were included (5 males, 2 females), with a median age of 52 (interquartile range [IQR] 44-55) years. The primary outcome was the Numeric Rating Scale (NRS) for pain during walking 2 years postoperatively. Range of motion (ROM), revision rates, and complications were assessed. A postoperative MRI scan was performed to assess progression of OA, graft position and ingrowth, and the degree of bone marrow edema. RESULTS: There was a 100% follow-up of the patients (median follow-up: 33 [IQR 26-33] months). The NRS during walking improved from 6 preoperatively to 2 at 2 years postoperatively ( < 0.05). There were no reoperations nor severe complications. The limitations in the ROM remained limited in the majority of the cases. MRI at 2 years of follow-up showed no progression of OA, reduced bone marrow edema, and no loosening of the grafts. CONCLUSION: Biological resurfacing arthroplasty with a fascia lata autograft (BioJoint procedure) for OA to one or more joints in the midtarsal joint complex showed clinically relevant pain reduction during walking, improvement in clinical and radiological outcomes, and proved to be safe and durable.
ObjectiveOsteochondral defects develop into osteoarthritis without intervention. Costal cartilage can be utilized as an alternative source for repairing osteochondral defect. Our previous clinical study has shown the suc...ObjectiveOsteochondral defects develop into osteoarthritis without intervention. Costal cartilage can be utilized as an alternative source for repairing osteochondral defect. Our previous clinical study has shown the successful osteochondral repair by costal cartilage graft with integration into host bone bed. In this study, we investigate how cartilaginous graft adapt to osteochondral environment and the mechanism of bone-cartilage interface formation.DesignCostal cartilage grafting was performed in C57BL/6J mice and full-thickness osteochondral defect was made as control. 3D optical profiles and micro-CT were applied to evaluate the reconstruction of articular cartilage surface and subchondral bone as well as gait analysis to evaluate articular function. Histological staining was performed at 2, 4, and 8 weeks after surgery. Moreover, costal cartilage from transgenic mice with fluorescent markers were transplanted into wild-type mice to observe the changes of costal chondrocytes.ResultsAt 8 weeks after surgery, 3D optical profiles and micro-CT showed that in the graft group, the articular surface and subchondral bone were well preserved. Gait analysis and International Cartilage Repair Society (ICRS) score evaluation showed a good recovery of joint function and histological repair in the graft group. Safranin O staining showed the gradual integration of graft and host tissue. Costal cartilage from transgenic mice with fluorescent markers showed that donor-derived costal chondrocytes turned into osteocytes in the subchondral area of host femur.ConclusionCostal cartilage grafting shows both functional and histological repair of osteochondral defect in mice. Graft-derived costal chondrocytes differentiate into osteocytes and contribute to endochondral ossification.
Objectivesα2-Macroglobulin (A2M) can prevent cartilage degeneration by blocking many types of cartilage-degrading enzymes, but the mechanism remains to be clarified. This study aimed to test that A2M protects against car...Objectivesα2-Macroglobulin (A2M) can prevent cartilage degeneration by blocking many types of cartilage-degrading enzymes, but the mechanism remains to be clarified. This study aimed to test that A2M protects against cartilage degeneration by promoting chondrocyte proliferation and cartilage matrix synthesis via inducing proliferating cell nuclear antigen (PCNA).DesignThe cartilage degeneration of the anterior cruciate ligament transection (ACLT) model was evaluated by Safranin O-fast green staining, and articular cartilage degeneration was graded using the Osteoarthritis Research Society International (OARSI)-modified Mankin criteria. The chondrocyte proliferation was detected by 5-Bromodeoxyuridinc (BrdU), MTT, and Cell Counting Kit-8 (CCK8) methods. The chondrocyte apoptosis was detected by lactate dehydrogenase (LDH) assay and Annexin PI staining with the flow cytometer. The glycosaminoglycan (sGAG) and aggrecan in culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to analyze the type II collagen and aggrecan mRNA expression. The PCNA protein expression was analyzed by western blot and immunofluorescent staining.ResultsA2M can attenuate cartilage degeneration in ACLT rats. The OARSI scores for cartilage degeneration in the A2M group were lower than those in the phosphate-buffered saline (PBS) group. A2M can promote chondrocyte proliferation and inhibit chondrocyte apoptosis, promote the cartilage matrix synthesis in chondrocytes (type II collagen and aggrecan), and culture supernatant (sGAG and aggrecan). At the same time, it also up-regulated the PCNA protein expression in chondrocytes.ConclusionsA2M can promote chondrocyte proliferation and cartilage matrix synthesis via inducing PCNA expression.
PURPOSE: To evaluate the clinical characteristics and global trends in the surgical treatment of articular cartilage defects. METHODS: Studies in English published between January 1, 2001 and December 31, 2020 were retri...PURPOSE: To evaluate the clinical characteristics and global trends in the surgical treatment of articular cartilage defects. METHODS: Studies in English published between January 1, 2001 and December 31, 2020 were retrieved from MEDLINE, WOS, INSPEC, SCIELO, KJD, and RSCI on the "Web of Science." Patient data were extracted, including age, sex, defect location and laterality, duration of follow-up and symptoms, and body mass index (BMI). Data were further stratified according to the surgical method, lesion location, procedural type and geographical area, and time period. A comparative analysis was performed. RESULTS: Overall, 443 studies involving 26,854 patients (mean age, 35.25 years; men, 60.5%) were included. The mean lesion size and patient BMI were 3.51 cm and 25.61 kg/m, respectively. Cartilage defects at the knees, talus, and hips affected 20,850 (77.64%), 3,983 (14.83%), and 1,425 (5.31%) patients, respectively. The numbers of patients who underwent autologous chondrocyte implantation, arthroscopic debridement/chondroplasty, osteochondral allograft (OCA), osteochondral autologous transplantation, and microfracture were 7,114 (26.49%), 5,056 (18.83%), 3,942 (14.68%), 3,766 (14.02%), and 2,835 (10.56%), respectively. European patients were the most numerous and youngest. North American patients had the largest defects. The number of patients increased from 305 in 2001 to 3,017 in 2020. In the last 5 years, the frequency of OCAs showed a greatly increasing trend. CONCLUSION: Clinical characteristics and global trends in the surgical treatment of articular cartilage defects were revealed. The choice of operation should be based on the patient characteristics and defect location, size, and shape, as well as the patient's preference.
OBJECTIVE: We aimed to evaluate the outcomes, survivorship, and complications following multi-surface cartilage procedures at minimum 2-year follow-up. DESIGN: Patients with either (1) single-surface osteochondral allogr...OBJECTIVE: We aimed to evaluate the outcomes, survivorship, and complications following multi-surface cartilage procedures at minimum 2-year follow-up. DESIGN: Patients with either (1) single-surface osteochondral allograft transplantation (OCAT) with third-generation matrix-induced autologous cultured chondrocyte implantation (MACI) or particulated juvenile cartilage implantation (DeNovo), or (2) multiple-surface OCAT ± associated MACI/DeNovo procedures for grade IV chondral or osteochondral defects about the knee with minimum 2-year follow-up were analyzed. Patient-reported outcome measures (PROMs), including International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, were obtained preoperatively and at minimum 2 years postoperatively. The percentage of patients who met the minimal clinically important difference (MCID) for each PROM was reported. Failure was defined as revision OCAT, conversion to patellofemoral/total/unicompartmental joint arthroplasty, or Arthrosurface HemiCAP placement. RESULTS: Of 257 patients identified, 35 were included. There was a significant increase in IKDC, KOOS-pain, KOOS-symptom, KOOS-sport, and KOOS-quality of life scores from preoperative to postoperative evaluation ( < 0.03 for all). More than 50% of patients met the MCID for each PROM. There were 2 failures, 1 of the patella and 1 of the medial femoral condyle, at 39.7 and 38.6 months postoperatively, respectively. DISCUSSION: Multi-surface cartilage procedures are a safe, efficacious treatment option for multifocal cartilage defects about the knee at short-term follow-up.
OBJECTIVE: Müller-Weiss disease (MWD) is a challenging condition involving the perinavicular region in the initial stages and subsequently the entire foot in the later stages. The goal of this article is to describe the...OBJECTIVE: Müller-Weiss disease (MWD) is a challenging condition involving the perinavicular region in the initial stages and subsequently the entire foot in the later stages. The goal of this article is to describe the pathomechanics, clinical evaluation, and nonoperative and operative treatment, including a treatment algorithm, based on current evidence and the combined authors' experience. DESIGN: We review the related articles and summarize the information about this condition. RESULTS: A number of related articles reveal that the treatments should focus on the management of degenerative regions and deformity correction to restore normal foot alignment and provide pain relief. CONCLUSION: This systematic review proposes a treatment algorithm that is comprehensive and practical to apply for the management of MWD.
OBJECTIVE: Mechanical alignment of the lower limbs has been suggested to cause abnormal uneven loading across the compartments at the knee, but its contribution to the initiation and progression of arthritis remains cont...OBJECTIVE: Mechanical alignment of the lower limbs has been suggested to cause abnormal uneven loading across the compartments at the knee, but its contribution to the initiation and progression of arthritis remains controversial. This study aimed to establish whether malalignment of the lower limb after trauma is associated with worsened arthritis scores in the theoretically overloaded compartment, and if arthritis scores continuously correlate with the degree of malalignment and time with deformity. DESIGN: After screening 1160 X-rays, 60 patients were identified with long-leg radiographs > 2 years after fracture. Measurement of mechanical axis deviation (MAD) divided into groups of varus malalignment ( = 16, >16 mm), valgus ( = 25, <0 mm), and normal alignment ( = 19). Alignment and bilateral knee compartmental arthritis scores were recorded by three clinicians, compared via analysis of variance and assessed with linear regression against time since injury using MAD as a covariate. RESULTS: In varus and valgus malalignment, there was a greater mean arthritis score in the "overloaded" compartment compared to the contralateral side, with varus medial Osteoarthritis Research Society International (OARSI) scores 5.17 ± 2.91 vs 3.50 ± 2.72 ( = 0.006) and Kellegren-Lawrence scores 2.65 ± 1.19 vs 1.79 ± 1.24 ( ≤ 0.001). In a linear regression model, OARSI arthritis score was significantly associated with absolute MAD (0.6/10 mm MAD, < 0.001) and time (0.7/decade, ≤ 0.001). CONCLUSIONS: Malalignment consistently results in more advanced arthritis scores in the overloaded compartment, most likely related to abnormal loading across the knee. Severity of arthritis using OARSI grading continuously correlates with degree of malalignment and time with deformity after post-traumatic malunion.
OBJECTIVE: Ultra-short TE (UTE) sequences on MRI are a technique that improves the visualization of tissues with short T2 relaxation time, such as deep cartilage layers. In addition, T2* relaxation time calculated from t...OBJECTIVE: Ultra-short TE (UTE) sequences on MRI are a technique that improves the visualization of tissues with short T2 relaxation time, such as deep cartilage layers. In addition, T2* relaxation time calculated from the UTE has the potential to evaluate water molecules bound to the cartilage matrix. This study was performed to determine if there is an association between UTE-T2* relaxation time by cartilage layer and histological degeneration in knee osteoarthritis (OA). DESIGN: Seven knees that had undergone total knee arthroplasty (TKA) were included in the study, and the lateral tibial cartilage, which had the least degeneration of the resected bones, was used as the sample. The T2* relaxation time of 4 patients with no abnormal findings on MRI was the reference relaxation time. Histological degeneration of TKA samples was assessed by the Mankin score and graded as the early OA group (≤3 points) and the advanced OA group (≥4 points). The association between T2* relaxation time and Mankin grade in each cartilage layer was compared. The effect of angiogenesis to the tidemark on T2* relaxation time was also compared. RESULTS: T2* relaxation time of the cartilage layer was significantly longer in early OA than that in the control group. In the deep cartilage layer, the mean T2* relaxation time for angiogenesis (-) was 15.7 ms, whereas it was significantly shorter for angiogenesis (+) at 8.2 ms. CONCLUSIONS: The UTE-T2* relaxation time was associated with histological cartilage degeneration, suggesting a potential application in monitoring early cartilage degeneration.