Surgical options for patients with osteoarthritis of the knee

Advancing Tissue Damage Repair in Geriatric Diseases: Prospects of Combining Stem Cell-Derived Exosomes with Hydrogels

Geriatric diseases are a group of diseases with unique characteristics related to senility. With the rising trend of global aging, senile diseases now mainly include endocrine, cardiovascular, neurodegenerative, skeletal, and muscular diseases and cancer. Compared with younger populations, the structure and function of various cells, tissues and organs in the body of the elderly undergo a decline as they age, rendering them more susceptible to external factors and diseases, leading to serious tissue damage. Tissue damage presents a significant obstacle to the overall health and well-being of older adults, exerting a profound impact on their quality of life. Moreover, this phenomenon places an immense burden on families, society, and the healthcare system.In recent years, stem cell-derived exosomes have become a hot topic in tissue repair research. The combination of these exosomes with biomaterials allows for the preservation of their biological activity, leading to a significant improvement in their therapeutic efficacy. Among the numerous biomaterial options available, hydrogels stand out as promising candidates for loading exosomes, owing to their exceptional properties. Due to the lack of a comprehensive review on the subject matter, this review comprehensively summarizes the application and progress of combining stem cell-derived exosomes and hydrogels in promoting tissue damage repair in geriatric diseases. In addition, the challenges encountered in the field and potential prospects are presented for future advancements.

New concept of orthosis treatment for knee osteoarthritis: Clinical and radiological outcomes

BACKGROUND

Given the increasing numbers of young patients with knee osteoarthritis there is a need for treatments that can postpone a joint prosthesis (total knee replacement).

OBJECTIVE

As an alternative to the effective yet invasive knee joint distraction procedure, a knee orthosis was developed aiming to unload the affected knee and improving synovial fluid flow. The aim of this study was to examine the effectiveness of using a load-reducing orthosis for two months on functioning, pain, and disease progression (e.g. amount of damaged cartilage) in patients with symptomatic osteoarthritis of the knee for at least one year.

METHODS

This is an interventional single-center pilot study. Ten patients with symptomatic osteoarthritis of one knee (5 males/5 females; median age 57; age range 42-59) used a custom-made orthosis for 60 days during daily life activities that involved knee loading (e.g. standing, walking, but not during stair climbing). Cycling was not allowed. Clinical outcomes were assessed up to 24 months after intervention at 6 timepoints using patient reported-outcome measures Western Ontario and McMaster Universities Osteoarthritis (WOMAC) range 0-100; Visual Analogue Scale (VAS), range 0-100 for pain. Minimum joint space width (mJSW) was assessed using knee images digital analysis (KIDA) and articular cartilage volume with magnetic resonance imaging (MRI) using custom software at baseline and at 12 and 24 months follow-up.

RESULTS

Clinically beneficial effects were found for functioning (WOMAC improvement compared to baseline ranged between 18 points at 3 months follow-up and 31 points at 12 months follow-up, with only the 24-months follow-up (improvement of 27 points) not reaching statistical significance (p< 0.05)) and for pain (VAS improvement compared to baseline at follow-up time points ranged between 41-56 points; all p< 0.05). No improvements in mJSW- or MRI-derived parameters were found.

CONCLUSION

This study demonstrates that use of a custom-made knee-unloading orthosis for 60 days can result in improved functional ability and decrease in pain in relatively young patients with knee osteoarthritis. No effect on disease progression could be evidenced.

Core Recommendations for Osteoarthritis Care: A Systematic Review of Clinical Practice Guidelines

OBJECTIVE

To evaluate the quality of clinical practice guidelines (CPGs) for interventions in management of osteoarthritis (OA) and to provide a synthesis of high-quality CPG recommendations.

METHODS

Five databases (OvidSP Medline, Cochrane, Cumulative Index to Nursing and Allied Health Literature [CINAHL], Embase, and the Physiotherapy Evidence Database [PEDro]) and 4 online guideline repositories were searched. CPGs for the management of OA were included if they were 1) written in English and published from January 2015 to February 2022, focused on adults age ≥18 years, and met the criteria of a CPG as defined by the Institute of Medicine; and 2) were rated as high quality on the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument. CPGs for OA were excluded if they were available via institutional access only, only addressed recommendations for the system/organization of care and did not include interventional management recommendations, and/or included other arthritic conditions.

RESULTS

Of 20 eligible CPGs, 11 were appraised as high quality and included in the synthesis. Of interest were the hip, knee, hand, and glenohumeral joints and/or polyarticular OA. Consistent recommendations were that care should be patient centered and include exercise, education, and weight loss (where appropriate). Nonsteroidal antiinflammatory drugs and surgical interventions were recommended for disabling OA that had not improved with nonsurgical care. Hand orthoses should be recommended for patients with hand OA.

CONCLUSION

This synthesis of high-quality CPGs for OA management offers health care providers with clear, simple guidance of recommended OA care to improve patient outcomes.

Donor-Matched Peripheral Blood-Derived Mesenchymal Stem Cells Combined With Platelet-Rich Plasma Synergistically Ameliorate Surgery-Induced Osteoarthritis in Rabbits: An In Vitro and In Vivo Study

BACKGROUND

Osteoarthritis (OA) is a common disease that causes joint pain and disability. Stem cell therapy is emerging as a promising treatment for OA.

PURPOSE

To evaluate the ability of peripheral blood-derived mesenchymal stem cells (PBMSCs) combined with donor-matched platelet-rich plasma (PRP) to treat OA in a rabbit model.

STUDY DESIGN

Controlled laboratory study.

METHODS

PBMSCs and donor-matched PRP were isolated and prepared from the same rabbit. PBMSCs were treated with serum-free medium, fetal bovine serum, and PRP; a series of PBMSC behaviors, including proliferation, migration, and adhesion, were compared among groups. The ability of PBMSCs or PRP alone and PBMSCs+PRP to protect chondrocytes against proinflammatory cytokine (interleukin 1β [IL-1β]) treatment was compared by analyzing reactive oxygen species (ROS)-scavenging ability and apoptosis. Real-time quantitative polymerase chain reaction and immunofluorescence were used to investigate the expression of extracellular matrix (ECM) metabolism genes and proteins, and Western blotting was used to explore the potential mechanism of the corresponding signaling pathway. In vivo, the effect of PBMSCs+PRP on cartilage and inflammation of the synovium was observed in a surgery-induced OA rabbit model via gross observation, histological and immunohistochemical staining, and enzyme-linked immunosorbent assay.

RESULTS

Proliferation, migration, and adhesion ability were enhanced in PBMSCs treated with PRP. Moreover, compared with either PBMSCs or PRP alone, PBMSCs+PRP enhanced ROS-scavenging ability and inhibited apoptosis in IL-1β-treated chondrocytes. PBMSCs+PRP also reversed the IL-1β-induced degradation of collagen type 2 and aggrecan and increased expression of matrix metalloproteinase 13, and this effect was related to increased expression of ECM synthesis and decreased expression of degradation and inflammatory genes and proteins. Mechanistically, PBMSCs+PRP reduced the phosphorylation of inhibitor of nuclear factor-κBα (IκBα), which further inhibited the phosphorylation of downstream nuclear factor-κB (NF-κB) in the NF-κB signaling pathway. In vivo, compared with PBMSCs or PRP alone, intra-articular (IA) injection of PBMSCs+PRP enhanced cartilage regeneration and attenuated synovial inflammation in OA-induced rabbits.

CONCLUSION

These results demonstrate that PRP could enhance biological activities, including viability, migration, and adhesion, in PBMSCs. PBMSCs+PRP could rescue ECM degeneration by inhibiting inflammatory signaling in IL-1β-treated OA chondrocytes. In addition, IA injection of PBMSCs+PRP effectively attenuated OA progression in a surgery-induced OA rabbit model.

CLINICAL RELEVANCE

PBMSCs+PRP may provide a promising treatment for knee OA, and this study can advance the related basic research.

Paroxetine Attenuates Chondrocyte Pyroptosis and Inhibits Osteoclast Formation by Inhibiting NF-κB Pathway Activation to Delay Osteoarthritis Progression

Background

Osteoarthritis (OA), a common chronic joint disease, is characterized by cartilage degeneration and subchondral bone reconstruction. NF-κB signaling pathway-activated inflammation and NLRP3-induced pyroptosis play essential roles in the development of OA. In this study, we examine whether paroxetine can inhibit pyroptosis and reduce osteoclast formation, thereby delaying the destruction of knee joints.

Methods

We employed high-density cultures, along with quantitative polymerase chain reactions and Western blotting techniques, to investigate the effects of paroxetine on extracellular matrix synthesis and degradation. The expression levels of NF-κB and pyroptosis-related signaling pathway proteins were examined by Western blotting and immunofluorescence. Furthermore, the impact of paroxetine on RANKL-induced osteoclast formation was evaluated through TRAP staining and F-actin ring fluorescence detection. To investigate the role of paroxetine in vivo, we constructed a mouse model with destabilization of the medial meniscus (DMM) surgery. Safranin O-Fast Green staining, Hematoxylin-Eosin staining, and immunohistochemistry were conducted to observe the extent of knee joint cartilage deformation. In addition, TRAP staining was used to observe the formation of osteoclasts in the subchondral bone.

Results

In the in vitro experiments with ATDC5, paroxetine treatment attenuated IL-1β-induced activation of the pyroptosis-related pathway and suppressed extracellular matrix catabolism by inhibiting the NF-kB signaling pathway. In addition, paroxetine treatment decreased the expression of RANKL-induced osteoclast marker genes and reduced osteoclast formation. In animal experiments conducted in vivo, mice treated with paroxetine exhibited thicker knee cartilage with a smoother surface compared to the DMM group. Additionally, the formation of osteoclasts in the subchondral bone was reduced in the paroxetine-treated mice. Further analysis revealed that paroxetine treatment played a role in preserving the balance of the extracellular matrix and delaying knee joint degeneration.

Conclusion

Paroxetine can inhibit pyroptosis and reduce osteoclast formation via inhibiting the NF-κB signaling pathway, suggesting that it may have therapeutic effects in patients with OA.

Bibliometric Analysis of Publications in Clinical Trials on Knee Osteoarthritis Between 2001 and 2022

Purpose

Clinical treatment of knee osteoarthritis has gained great interest, and numerous clinical studies have been reported. Few studies have described the detailed characterizations of clinical trials on knee osteoarthritis. This study is to identify, visualize, and characterize the clinical trials in knee osteoarthritis research.

Design and Methods

Articles published in recent two decades were extracted from the Web of Science core collection database using a query based on MeSH terms and topics of knee osteoarthritis and clinical trial. Basic characteristics of publications were analyzed based on the publication year, authors, institutions, counties, and keywords covered in the article. CiteSpace and VOS viewer were used for data visualization. The data were retrieved on May 28, 2022.

Results

A total of 1972 trials on knee osteoarthritis were identified. The number of publications has experienced rapid growth in the past two decades. America, England, and China had strong contributions in publication. Osteoarthritis and Cartilage, Annals of the Rheumatic Diseases and American Journal of Sports Medicine were highly cited and bellwether journals. Clustering mapping of the collaborative network, co-citation, and co-occurrence analyses showed that the research hotspots are mainly focused on disease-modifying medications, intra-articular injections, physical therapy for symptom control, lifestyle intervention, Chinese medicine treatment, and knee replacement.

Conclusion

Clinical treatments of knee OA are evolving. Pharmacologic therapy, intra-articular therapy, nonpharmacologic therapy including exercise or diet, self-management programs, Chinese medicine treatment, and knee replacement were highly represented in clinical trials of knee OA. Adjustment of combination therapy may be the next study focus in the future.

Comparison of Femoral Component Rotation between Robotic-Assisted vs. Soft-Tissue Tensor Total Knee Arthroplasty with Anatomic Implants

Background and Objectives: Total knee arthroplasty (TKA) is the most effective treatment method for end-stage osteoarthritis. One of the most important aspects of this surgery is adequate implant positioning, as it guarantees the desired outcome of restoring limb biomechanics. Surgical technique is being continuously improved along with hardware development. There are two novel devices designed to help establish proper femoral component rotation: soft-tissue tensor and robotic-assisted TKA (RATKA). This study compared the femoral component rotation achieved with the use of three methods: RATKA, soft tissue tensioner and the conventional measured-resection technique, all of them utilizing anatomical design prosthesis components. Materials and Methods: A total of 139 patients diagnosed with end-stage osteoarthritis underwent total knee arthroplasty between December 2020 and June 2021. After the surgery, they were divided into three groups depending on procedure technique and implant type: Persona (Zimmer Biomet) + Fuzion Balancer, RATKA + Journey II BCS or conventional TKA + Persona/Journey. Postoperatively, a computed tomography examination was performed in order to measure femoral component rotation. All three groups were compared independently during statistical analysis. Fisher's exact, Kruskal-Wallis and Dwass-Steel-Crichtlow-Fligner tests were used for particular calculations. Results: Statistically significant differences in femoral component rotation between groups were noticed. However, in terms of values other than 0° in external rotation, no significant variance was revealed. Conclusions: Additional total knee arthroplasty instruments seem to improve the outcomes of the surgery, providing better component positioning than in the conventional measured-resection technique based only on bone landmarks.

Key-point estimation of knee X-ray images using a parallel fusion decoding network

BACKGROUND

High tibial osteotomy (HTO) is a knee preservation procedure used to treat osteoarthritis of the knee. Identifying the hinge point, surgical point, and Fujisawa point in the patient's knee X-ray before surgery is a critical task. The aim of this study was to propose an artificial intelligence-based method to effectively help surgeons select the location of these landmark points, which provides important reference for subsequent surgery.

METHODS

We proposed PFDNet (parallel fusion decoding network), a novel convolutional neural network for key-point estimation of knee X-rays. PFDNet employs Res2Net for feature extraction in the network encoding phase and two partial decoders connected in parallel in the network decoding phase to finely aggregate the multiscale feature information produced by Res2Net. A total of 1842 knee X-ray images were trained, validated and predicted by PFDNet to determine whether the network could accurately detect key-points in the HTO surgical plan.

RESULTS

At the hinge point, surgical point, and Fujisawa point, the average error and standard deviation from the calibration value in the PFDNet test results were 2.06 ± 1.165 mm, 2.713 ± 1.457 mm, and 2.015 ± 1.304 mm, respectively. This method exhibits superior performance compared with four convolutional neural network models that are also based on encoding and decoding frameworks: U-Net, ResUnet, SegNet, and FCN.

CONCLUSION

The hinge point, surgical point, and Fujisawa point can be clearly selected by PFDNet from knee X-ray images and is locked to the millimeter level. The results show that the proposed artificial intelligence-based strategy can be instrumental in preoperative HTO planning.

Engineering Hyaluronic Acid for the Development of New Treatment Strategies for Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that is characterized by inflammation of the joints, degradation of cartilage, and the remodeling of other joint tissues. Due to the absence of disease-modifying drugs for OA, current clinical treatment options are often only effective at slowing down disease progression and focus mainly on pain management. The field of tissue engineering has therefore been focusing on developing strategies that could be used not only to alleviate symptoms of OA but also to regenerate the damaged tissue. Hyaluronic acid (HA), an integral component of both the synovial fluid and articular cartilage, has gained widespread usage in developing hydrogels that deliver cells and biomolecules to the OA joint thanks to its biocompatibility and ability to support cell growth and the chondrogenic differentiation of encapsulated stem cells, providing binding sites for growth factors. Tissue-engineering strategies have further attempted to improve the role of HA as an OA therapeutic by developing diverse modified HA delivery platforms for enhanced joint retention and controlled drug release. This review summarizes recent advances in developing HA-based hydrogels for OA treatment and provides additional insights into how HA-based therapeutics could be further improved to maximize their potential as a viable treatment option for OA.

Method Categorization of Stem Cell Therapy for Degenerative Osteoarthritis of the Knee: A Review

Current clinical applications of mesenchymal stem cell therapy for osteoarthritis lack consistency because there are no established criteria for clinical processes. We aimed to systematically organize stem cell treatment methods by reviewing the literature. The treatment methods used in 27 clinical trials were examined and reviewed. The clinical processes were separated into seven categories: cell donor, cell source, cell preparation, delivery methods, lesion preparation, concomitant procedures, and evaluation. Stem cell donors were sub-classified as autologous and allogeneic, and stem cell sources included bone marrow, adipose tissue, peripheral blood, synovium, placenta, and umbilical cord. Mesenchymal stem cells can be prepared by the expansion or isolation process and attached directly to cartilage defects using matrices or injected into joints under arthroscopic observation. The lesion preparation category can be divided into three subcategories: chondroplasty, microfracture, and subchondral drilling. The concomitant procedure category describes adjuvant surgery, such as high tibial osteotomy. Classification codes were assigned for each subcategory to provide a useful and convenient method for organizing documents associated with stem cell treatment. This classification system will help researchers choose more unified treatment methods, which will facilitate the efficient comparison and verification of future clinical outcomes of stem cell therapy for osteoarthritis.

Primary Care Provider Density and Elective Total Joint Replacement Outcomes

BACKGROUND

Primary care physicians (PCPs) are often gatekeepers to specialist care. This study assessed the relationship between PCP density and total knee (TKA) and total hip arthroplasty (THA) outcomes.

METHODS

We obtained patient-level data from an institutional registry on patients undergoing elective primary TKA and THA for osteoarthritis, including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores at baseline and 2 years. Using geocoding, we identified the number of PCPs in the patient's census tract (communities). We used Augmented Inverse Probability Weighting and Cross-validated Targeted Minimum Loss-Based Estimation to compare provider density and outcomes adjusting for potential confounders.

RESULTS

Our sample included 3606 TKA and 4295 THA cases. The median number of PCPs in each community was similar for both procedures: TKA 2 (interquartile range 1, 6) and for THA 2 (interquartile range 1, 7). Baseline and 2-year follow-up WOMAC pain, function, and stiffness scores were not statistically significantly different comparing communities with more than median number of PCPs to those with less than median number of PCPs. In sensitivity analyses, adding 1 PCP to a community with zero PCPs would not have statistically significantly improved baseline or 2-year follow-up WOMAC pain, function, and stiffness scores.

CONCLUSIONS

In this sample of patients who underwent elective TKA or THA for osteoarthritis, we found no statistically significant association between PCP density and pain, function, or stiffness outcomes at baseline or 2 years. Further studies should examine what other provider factors affect access and outcomes in THA and TKA.

Real-World Health Care Resource Utilization and Costs Among US Patients with Knee Osteoarthritis Compared with Controls

PURPOSE

To determine the prevalence, healthcare resource utilization and costs (HCRU&C) of knee osteoarthritis (OA) patients versus controls.

PATIENTS AND METHODS

Retrospective, matched-cohort administrative claims analysis using IBM MarketScan databases (2011-2017). Newly diagnosed, adult (18+ yrs) knee OA patients identified by ICD9/10 code were matched 1:1 to controls by age, sex, payer, and geography; alpha level set to 0.05. Prevalence was estimated for 2017. All-cause and knee OA-related HCRU&C reported per-patient-per-year (PPPY) over follow-up period up to 4 years.

RESULTS

Overall 2017 knee OA prevalence was 4% (615,514 knee OA/15.4M adults). A total of 510,605 patients meeting inclusion criteria were matched 1:1 with controls. The knee OA cohort had mean age 60 years and was 58% female. Versus controls, knee OA patients had significantly more PPPY outpatient (84.5 versus 45.0) and pharmacy (29.8 versus 19.8) claims, and significantly higher PPPY outpatient costs ($12,571 versus $6,465), and pharmacy costs ($3,655 versus $2,038). Knee OA patients incurred $7,707 more PPPY total healthcare costs than controls, of which $4,674 (60.6%) were knee OA-related medical claims and $1,926 (25%) were knee OA-related medications of interest. PPPY costs for nonselective NSAIDs, cyclooxygenase-2 (COX-2) inhibitors, intraarticular hyaluronic acid, non-acute opioids, and knee replacement were higher for knee OA patients than controls. Using median and mean all-cause total cost ($9,330 and $24,550, respectively), the estimated sum cost of knee OA patients in MarketScan ranged from $5.7B to $15B annually.

CONCLUSION

This retrospective analysis demonstrated an annual 2017 prevalence of 4.0% (≥18 years) and 13.2% (≥65 years) for newly diagnosed knee OA patients. Compared with controls, all-cause costs were significantly higher for knee OA patients, nearly double that of matched controls, attributable to increased medical and treatment costs and comorbidity treatment burden. Additionally, the estimated annual cost of knee OA treatment was substantial, ranging between $5.7 billion and $15 billion.

Development of a multivariable prediction model for early revision of total knee arthroplasty - The effect of including patient-reported outcome measures

Background

Revision TKA is a serious adverse event with substantial consequences for the patient. As revision is becoming increasingly common in patients under 65 years, the need for improved preoperative patient selection is imminently needed. Therefore, this study aimed to identify the most important factors of early revision and to develop a prediction model of early revision including assessment of the effect of incorporating data on patient-reported outcome measures (PROMs).

Material and methods

A cohort of 538 patients undergoing primary TKA was included. Multiple logistic regression using forward selection of variables was applied to identify the best predictors of early revision and to develop a prediction model. The model was internally validated with stratified 5-fold cross-validation. This procedure was repeated without including data on PROMs to develop a model for comparison. The models were evaluated on their discriminative capacity using area under the receiver operating characteristic curve (AUC).

Results

The most important factors of early revision were age (OR 0.63 [0.42, 0.95]; P = 0.03), preoperative EQ-5D (OR 0.07 [0.01, 0.51]; P = 0.01), and number of comorbidities (OR 1.01 [0.97, 1.25]; P = 0.15). The AUCs of the models with and without PROMs were 0.65 and 0.61, respectively. The difference between the AUCs was not statistically significant (P = 0.32).

Conclusions

Although more work is needed in order to reach a clinically meaningful quality of the predictions, our results show that the inclusion of PROMs seems to improve the quality of the prediction model.

Changes in Cartilage Thickness and Denuded Bone Area after Knee Joint Distraction and High Tibial Osteotomy-Post-Hoc Analyses of Two Randomized Controlled Trials

High tibial osteotomy (HTO) and knee joint distraction (KJD) are joint-preserving treatments that unload the more affected compartment (MAC) in knee osteoarthritis. This post-hoc study compares two-year cartilage-thickness changes after treatment with KJD vs. HTO, and identifies factors predicting cartilage restoration. Patients indicated for HTO were randomized to KJD (KJD_HTO) or HTO treatment. Patients indicated for total knee arthroplasty received KJD (KJD_TKA). Outcomes were the MRI mean MAC cartilage thickness and percentage of denuded bone area (dABp) change two years after treatment, using radiographic joint space width (JSW) as the reference. Cohen’s d was used for between-group effect sizes. Post-treatment, KJD_HTO patients (n = 18) did not show significant changes. HTO patients (n = 33) displayed a decrease in MAC cartilage thickness and an increase in dABp, but an increase in JSW. KJD_TKA (n = 18) showed an increase in MAC cartilage thickness and JSW, and a decrease in dABp. Osteoarthritis severity was the strongest predictor of cartilage restoration. Kellgren–Lawrence grade ≥3 showed significant restoration (p < 0.01) after KJD; grade ≤2 did not. Effect sizes between severe KJD and HTO patients were large for MAC MRI cartilage thickness (d = 1.09; p = 0.005) and dABp (d = 1.13; p = 0.003), but not radiographic JSW (d = 0.28; p = 0.521). This suggests that in knee osteoarthritis patients with high disease severity, KJD may be more efficient in restoring cartilage thickness.

Machine learning and wearable sensors at preoperative assessments: Functional recovery prediction to set realistic expectations for knee replacements

Unmet expectations contribute to a high patient dissatisfaction rate following total knee replacement but clinicians currently do not have the tools to confidently adjust expectations. In this study, supervised machine learning was applied to multi-variate wearable sensor data from preoperative timed-up-and-go tests. Participants (n=82) were instrumented three months after surgery and patients showing relevant improvement were designated as "responders" while the remainder were labelled "maintainers". Support vector machine, naïve Bayes, and random forest binary classifiers were developed to distinguish patients using sensor-derived features. Accuracy, sensitivity, specificity, and area under the receiver-operator curve (AUC) were compared between models using ten-fold out-of-sample testing. A high performance using only sensor-derived functional metrics was obtained with a random forest model (accuracy = 0.76 ± 0.11, sensitivity = 0.87 ± 0.08, specificity = 0.57 ± 0.26, AUC = 0.80 ± 0.14) but highly sensitive models were observed using naïve Bayes and SVM models after including patient age, sex, and BMI into the feature set (accuracy = 0.72, 0.73 ± 0.09, 0.12; sensitivity = 0.94, 0.95 ± 0.11, 0.11; specificity = 0.35, 0.37 ± 0.20, 0.18; AUC = 0.80, 0.74 ± 0.07, 0.11; respectfully). Including select patient-reported subjective measures increased the top random forest performance slightly (accuracy = 0.80 ± 0.10, sensitivity = 0.91 ± 0.14, specificity = 0.62 ± 0.23, AUC = 0.86 ± 0.09). The current work has demonstrated that prediction models developed from preoperative sensor-derived functional metrics can reliably predict expected functional recovery following surgery and this can be used by clinicians to help set realistic patient expectations.

Closing-wedge high tibial osteotomy, a reliable procedure for osteoarthritic varus knee

PURPOSE

The purpose of this study was to analyze the long-term clinical and radiological outcomes of patients who underwent closing-wedge High Tibial Osteotomy (HTO) for the treatment of medial compartment osteoarthritis and to evaluate the conversion rate to knee arthroplasty.

METHODS

A retrospective, non-randomized, monocentric study was performed in our Institution considering 166 patients between 1989 and 2012. The final population was composed by 82 patients (94 knees), median age at time of operation was 53 (range 45-73) years. All patients were evaluated clinically (HSS Score, Tegner Scale, VAS and Crosby-Insall Grading) and radiographically (osteoarthritis staging, hip-knee-ankle (HKA) angle, tibial slope and metaphyseal varus).

RESULTS

Mean follow-up was 11.9 ± 7.2 years. HSS Score increased significantly from 70.8 ± 10 to 93.2 ± 9.1 (p < 0.05) instead Tegner Scale increased from 1.3 ± 0 (range 1-4) to 2.8 ± 0.7 (range 2-6) at the last control (n.s.); VAS score significantly decreased from 7.9 ± 1.4 to 1.6 ± 1.1 (p < 0.05) at last follow-up. According to the Crosby-Insall Grading System, 80 patients (97.4%) reported excellent-good results. HKA angle decreased from 6.9° ± 3.5 to 2.6° ± 2.6 (p < 0.01), tibial slope decreased from 10.1° ± 1.4 to 6.8° ± 2.1 (p < 0.05) and finally the metaphyseal varus decreased from 4.2° ± 0 to 2.1° ± 1.2 (n.s.) at the last follow-up. Adverse events were reported in 4.8%. Osteotomy survivorship rate resulted 92% at 10 years, 82% at 15 years and 80% at 20 years. Sixteen revisions (9.6%) were reported at a mean period of 12.8 years.

CONCLUSIONS

CW-HTO is a valid option for medial osteoarthritis treatment, with successful results in both clinical and radiological outcomes.

LEVEL OF EVIDENCE

IV.

Non-surgical management of knee osteoarthritis: comparison of ESCEO and OARSI 2019 guidelines

Knee osteoarthritis (OA) is a heterogeneous disease associated with substantial effects on quality of life, and its clinical management is difficult. Among the several available guidelines for the management of knee OA, those from OARSI and ESCEO were updated in 2019. Here, we examine the similarities and differences between these two guidelines and provide a narrative to help guide health-care providers through the complexities of non-surgical management of knee OA. OARSI and ESCEO both recommend education, structured exercise and weight loss as core treatments, topical NSAIDs as first-line treatments and oral NSAIDs and intra-articular injections for persistent pain. Low-dose, short-term acetaminophen, pharmaceutical grade glucosamine and chondroitin sulfate are recommended by ESCEO whereas OARSI strongly recommends against their use (including all glucosamine and chondroitin formulations). Despite this difference, the two guidelines are consistent in the majority of their recommendations and provide useful treatment recommendations for individuals with OA and health-care providers.

Stem cell-directed therapies for osteoarthritis: The promise and the practice

Osteoarthritis (OA) is a disease of an entire synovial joint characterized by clinical symptoms and distortion of joint tissues, including cartilage, muscles, ligaments, and bone. Although OA is a disease of all joint tissues, it is a defined accessible compartment and is thus amenable to topical surgical and regenerative therapies, including stem cells. All tissues arise from stem progenitor cells, and the relative capacity of different cellular compartments, and different individuals, to renew tissues into adulthood may be important in the onset of many different degenerative diseases. OA is driven by both mechanical and inflammatory factors, but how these factors affect the proliferation and differentiation of cells into cartilage in vivo is largely unknown. Indeed, our very basic understanding of the physiological cellular kinetics and biology of the stem-progenitor cell unit of the articular cartilage, and how this is influenced by mechano-inflammatory injury, is largely unknown. OA seems, rather deceptively, to be the low-hanging fruit for stem cell therapy. Without the basic understanding of the stem cell and progenitor unit that generate and maintain articular cartilage in vivo, we will continue to waste opportunities to both prevent and manage this disease. In this review, we discuss the biology of chondrogenesis, the stem cell populations that support articular cartilage in health and disease, and future opportunities afforded through the translation of basic articular chondrocyte stem cell biology into new clinical therapies.

Characterization of Post-Traumatic Osteoarthritis in Rats Following Anterior Cruciate Ligament Rupture by Non-Invasive Knee Injury (NIKI)

Small animal models are essential for studying anterior cruciate ligament (ACL) injury, one of the leading risk factors for post-traumatic osteoarthritis (PTOA). Non-surgical models of ACL rupture have recently surged as a new tool to study PTOA, as they circumvent the confounding effects of surgical disruption of the joint. These models primarily have been explored in mice and rabbits, but are relatively understudied in rats. The purpose of this work was to establish a non-invasive, mechanical overload model of ACL rupture in the rat and to study the disease pathogenesis following the injury. ACL rupture was induced via non-invasive tibial compression in Lewis rats. Disease state was characterized for 4 months after ACL rupture via histology, computed tomography, and biomarker capture from the synovial fluid. The non-invasive knee injury (NIKI) model created consistent ACL ruptures without direct damage to other tissues and resulted in conventional OA pathology. NIKI knees exhibited structural changes as early as 4 weeks post-injury, including regional structural changes to cartilage, chondrocyte and cartilage disorganization, changes to the bone architecture, synovial hyperplasia, and the increased presence of biomarkers of cartilage fragmentation and pro-inflammatory cytokines. These results suggest that this model can be a valuable tool to study PTOA. By establishing the fundamental pathogenesis of this injury, additional opportunities are created to evaluate unique contributing factors and potential therapeutic interventions for this disease. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:356-367, 2020.

Partial or total knee replacement? Identifying patients' information needs on knee replacement surgery: a qualitative study to inform a decision aid

Purpose

For patients with end-stage knee osteoarthritis, joint replacement is a widely used and successful operation to help improve quality-of-life when non-operative measures have failed. For a significant proportion of patients there is a choice between a partial or total knee replacement. Decision aids can help people weigh up the need for and benefits of treatment against possible risks and side-effects. This study explored patients’ experiences of deciding to undergo knee replacement surgery to identify information priorities, to inform a knee replacement decision aid.

Methods

Four focus groups were held with 31 patients who were candidates for both partial and total knee replacement surgery. Two focus groups included patients with no prior knee replacement surgery (pre-surgery); two with patients with one knee already replaced and who were candidates for a second surgery on their other knee (post-surgery). Data were analysed using Framework Analysis.

Results

Participants described a process of arriving at ‘readiness for surgery’ a turning point where the need for treatment outweighed their concerns. Referral and personal factors influenced their decision-making and expectations of surgery in the hope to return to a former self. Those with previous knee surgery offered insights into whether their expectations were met. ‘Information for decisions’ details the practicality and the optimal timing for the delivery of a knee replacement decision aid. In particular, participants would have valued hearing about the experiences of other patients and seeing detailed pictures of both surgical options. Information priorities were identified to include in a decision aid for knee replacement surgery.

Conclusions

Patients’ experiences of surgical decision-making have much in common with the Necessity-Concerns Framework. Whilst originally developed to understand drug treatment decisions and adherence, it provides a useful lens to understand decision-making about surgery. The use of a decision aid could enhance decision-making on knee replacement surgery. Ultimately, patients’ understanding of the risks and benefits of both surgical options could be improved and in turn, help informed decision-making. The knee replacement decision aid is perceived as a useful tool to be associated with other detailed information resources as recommended.

Electronic supplementary material

The online version of this article (10.1007/s11136-019-02381-9) contains supplementary material, which is available to authorized users.

Effect of Germanium-Embedded Knee Sleeve on Osteoarthritis of the Knee

Background

Knee osteoarthritis (OA) affects an estimated 1 in 5 individuals older than 45 years of age in the United Kingdom. Previous studies have suggested that germanium-infused garments may provide improved clinical outcomes in OA. Germanium-embedded (GE) knee sleeves embrace this fabric technology.

Purpose

To assess the outcomes of GE knee sleeves for patients with knee OA.

Study Design

Cohort study; Level of evidence, 2.

Methods

This study was undertaken at a hospital in the United Kingdom. Patients who had radiographic features of OA, experienced knee pain for at least 6 months, and opted for nonsurgical intervention were included. Patients were recruited over 3 months. The University of California, Los Angeles activity score, Lysholm score, visual analog scale (VAS) score, and Oxford Knee Score (OKS) were collected at monthly intervals for 6 months. Patients were followed to determine their compliance with wearing the knee sleeves at all times, as advised, and whether any adverse effects had occurred.

Results

A total of 50 participants were recruited for the study; 4 participants were excluded due to pain and were converted to surgical management. Therefore, 46 patients were analyzed and placed into 2 groups according to severity of OA, as classified by the Kellgren-Lawrence system: group A had grade 1 or 2 OA, and group B had grade 3 or 4 OA. There were 25 patients in group A and 21 in group B. Improvements were seen in OKS, VAS, and Lysholm scores in both groups. Clinically significant improvements were seen in group A only for OKS (mean increase, 14), VAS (mean decrease, 4.1), and Lysholm (mean increase, 17.2) scores. These results were also statistically significant (OKS, P = 5.8 × 10^-7; VAS, P = 7.7 × 10^-12; Lysholm, P = 4.2 × 10^-11). The data from this study demonstrated that GE knee sleeves gave better outcomes for patients with grades 1 and 2 OA compared with patients with more advanced disease, which is consistent with previous studies. A total of 3 patients reported skin irritation, which resolved with simple skin ointment application. No patients reported infection, deep vein thrombosis, or circulation problems.

Conclusion

GE knee sleeves could play an important role in optimizing nonsurgical management of patients with knee OA, especially patients with grades 1 and 2 OA, as demonstrated by the clinically significant improvements.

Innate glycosidic activity in metallic implants for localized synthesis of antibacterial drugs

The unexpected discovery presented herein is that industrialized metallic wires can perform conversion of the glucuronide prodrugs with ensuing antibacterial effects.

Faster return to sport after robotic-assisted lateral unicompartmental knee arthroplasty: a comparative study

INTRODUCTION

Unicompartmental knee arthroplasty (UKA) is frequently performed on active patients with symptomatic osteoarthritis who desire a quick return to sports. The aim of this study was to compare return to sport after lateral UKA performed by robotic-assisted and conventional techniques.

MATERIALS AND METHODS

This retrospective study has assessed 28 lateral UKA (25 patients), 11 performed with robotic-assisted technique and 17 with conventional technique, between 2012 and 2016. The mean age was 65.5 and 59.5 years, with a mean follow-up of 34.4 months (range 15-50) and 39.3 months (range 22-68). Both groups were comparable pre-operatively. Sport habits and the details of the return to sports were assessed using University of California, Los Angeles Scale (UCLA) and direct questioning.

RESULTS

Robotic-assisted surgical technique provided significantly quicker return to sports than conventional technique (4.2 ±1.8 months; range 1-6 vs 10.5 ± 6.7 months; range 3-24; p < 0.01), with a comparable rate of return to sports (100% vs 94%). The practiced sports after lateral UKA were similar to those done preoperatively, with mainly low- and mid-impact sports (hiking, cycling, swimming, and skiing).

CONCLUSION

Robotic-assisted lateral UKA reduces the time to return to sports at pre-symptomatic levels when compared with conventional surgical technique. The return to sports rate after surgery is high in both groups. A long-term study would provide data on the prothesis wear in this active population.

LEVEL OF EVIDENCE

Comparative retrospective study, Level III.

Initial tissue repair predicts long-term clinical success of knee joint distraction as treatment for knee osteoarthritis

OBJECTIVE

Knee joint distraction (KJD), a joint-preserving surgery for severe osteoarthritis (OA), provides clinical and structural improvement and postpones the need for total knee arthroplasty (TKA). This study evaluates 9-year treatment outcome and identifies characteristics predicting long-term treatment success.

DESIGN

Patients with severe tibiofemoral OA (n = 20; age<60 years) indicated for TKA were treated with KJD. Questionnaires, radiographs, and magnetic resonance imaging (MRI) were used for evaluation. Survival after treatment was analyzed, where 'failure' was defined by TKA over time.

RESULTS

9-year survival was 48%, and 72% for men (compared to 14% for women; P = 0.035) and 73% for those with a first-year minimum joint space width (JSW) increase of >0.5 mm (compared to 0% for <0.05 mm; P = 0.002). Survivors still reported clinical improvement compared to baseline (ΔWOMAC +29.9 points (95%CI 16.9-42.9; P = 0.001), ΔVAS -46.8 mm (-31.6-61.9; P < 0.001)). Surprisingly, patients getting TKA years after KJD still reported clinical improvement although less pronounced (ΔWOMAC +20.5 points (-1.8-42.8; P = 0.067), ΔVAS -25.4 mm (-3.2-47.7; P = 0.030)). Survivors showed long-lasting minimum JSW increase (baseline 0.3 mm (IQR 1.9), follow-up 1.3 mm (2.5); P = 0.017) while 'failures' did not (baseline 0.4 mm (1.8), follow-up 0.2 mm (1.5); P = 0.161). First-year minimum JSW on radiographs and cartilage thickness increase on MRI predict 9-year survival (HR 0.05 and 0.12, respectively; both P < 0.026). Male gender was associated with survival (HR 0.24; P = 0.050).

CONCLUSIONS

KJD shows long-lasting clinical and structural improvement. In addition to a greater survival rate for males (>two out of three), the initial cartilage repair activity appears to be important for long-term clinical success.

Sociodemographic and Clinical Correlates of Physical Therapy Utilization in Adults With Symptomatic Knee Osteoarthritis

BACKGROUND

Physical therapy is essential for conservative management of symptomatic knee osteoarthritis (OA). However, physical therapy utilization data are limited for knee OA.

OBJECTIVE

The purpose of this study is to identify correlates of physical therapy utilization among adults with symptomatic knee OA.

DESIGN

The design consisted of secondary analysis using baseline data from a randomized controlled trial of 350 adults with physician-diagnosed symptomatic knee OA.

METHODS

Patients completed baseline surveys regarding demographics, pain, function, medical history, and prior physical therapy utilization for symptomatic knee OA. Multivariable logistic regression identified correlates of physical therapy utilization, with models adjusted for body mass index and age. Interactions of race and sex with all other characteristics were evaluated.

RESULTS

One hundred and eighty-one patients (52%) reported prior physical therapy utilization. Factors independently associated with increased odds of physical therapy utilization were female sex (odds ratio [OR] = 3.06, 95% CI = 1.58-5.93), bachelor degree or higher degree (OR = 2.44, 95% CI = 1.15-5.16), prior knee injury (OR = 1.86, 95% CI = 1.08-3.19), and duration of knee OA symptoms (OR = 2.16, 95% CI = 1.09-4.29 for >5-10 years; OR = 2.11, 95% CI = 1.10-4.04 for >10 years). Whites who had received a joint injection were >3 times as likely to have utilized physical therapy (OR = 3.69, 95% CI = 1.94-7.01); this relationship did not exist for non-whites who had received joint injections.

LIMITATIONS

A sample enrolled in an exercise study may limit generalizability. Self-report of physical therapy may misclassify utilization. It cannot be determined whether lack of utilization resulted from lack of referral or from patients choosing not to attend physical therapy.

CONCLUSION

Physical therapy is underutilized to manage symptomatic knee OA. Women and those with a bachelor degree or higher degree, prior knee injury, and longer duration of knee OA symptoms were more likely to have used therapy previously. Differences by race in the link between joint injection and physical therapy utilization may reflect a reduced likelihood of referral and decreased use of health interventions for symptomatic knee OA among non-whites, or both.

Time Trends in Characteristics of Patients Undergoing Primary Total Hip and Knee Arthroplasty in California, 2007-2010

BACKGROUND

As the number of total hip and knee arthroplasty cases increases, it is important to understand the burden of factors that impact patient outcomes of these procedures. This article examined the time trends in key demographics, clinical characteristics, comorbidity burden (Deyo-Charlson Comorbidity Index [CCI]), and presence of depression in patients undergoing primary total hip arthroplasty and total knee arthroplasty using population-based, all-payer inpatient database, California Healthcare Cost and Utilization Project, from 2007 to 2010.

METHODS

Chi-square tests and analysis of variance were used. Multivariate logistic regression analyses were also performed to compare the prevalence of depression in 2007 to later years.

RESULTS

In the primary total hip arthroplasty cohort, the prevalence of depression significantly increased by 20%, mean age decreased by 0.4 years, mean length of stay (LOS) decreased by 0.5 days, and having a CCI score of ≥3 increased by 30% (P value < .001 for all) over the study period. Similarly, in the primary total knee arthroplasty cohort, the prevalence of depression increased by 23%, the mean age decreased by 0.4 years, mean LOS decreased by 0.4 days, and the prevalence of CCI score of ≥3 increased by 35% (P value < .001 for all).

CONCLUSION

Despite the younger age of the joint arthroplasty population over time, we found increased prevalence of depression and comorbidity scores but shorter LOS. Further study is needed to determine the impact of the changing demographics of the total joint population and the best strategies to optimize their outcome with these procedures.

Cost-effectiveness of unicompartmental compared with total knee replacement: a population-based study using data from the National Joint Registry for England and Wales

OBJECTIVES

To assess the value for money of unicompartmental knee replacement (UKR) compared with total knee replacement (TKR).

DESIGN

A lifetime Markov model provided the framework for the analysis.

SETTING

Data from the National Joint Registry (NJR) for England and Wales primarily informed the analysis.

PARTICIPANTS

Propensity score matched patients in the NJR who received either a UKR or TKR.

INTERVENTIONS

UKR is a less invasive alternative to TKR, where only the compartment affected by osteoarthritis is replaced.

PRIMARY OUTCOME MEASURES

Incremental quality-adjusted life years (QALYs) and healthcare system costs.

RESULTS

The provision of UKR is expected to lead to a gain in QALYs compared with TKR for all age and gender subgroups (male: <60 years: 0.12, 60-75 years: 0.20, 75+ years: 0.19; female: <60 years: 0.10, 60-75 years: 0.28, 75+ years: 0.44) and a reduction in costs (male: <60: £-1223, 60-75 years: £-1355, 75+ years: £-2005; female: <60 years: £-601, 60-75 years: £-935, 75+ years: £-1102 per patient over the lifetime). UKR is expected to lead to a reduction in QALYs compared with TKR when performed by surgeons with low UKR utilisation but an increase among those with high utilisation (<10%, median 6%: -0.04, ≥10%, median 27%: 0.26). Regardless of surgeon usage, costs associated with UKR are expected to be lower than those of TKR (<10%: £-127, ≥10%: £-758).

CONCLUSIONS

UKR can be expected to generate better health outcomes and lower lifetime costs than TKR. Surgeon usage of UKR does, however, have a significant impact on the cost-effectiveness of the procedure. To achieve the best results, surgeons need to perform a sufficient proportion of knee replacements as UKR. Low usage surgeons may therefore need to broaden their indications for UKR.

A pilot hole does not reduce the strains or risk of fracture to the lateral cortex during and following a medial opening wedge high tibial osteotomy in cadaveric specimens

Aim

It has been suggested that the use of a pilot-hole may reduce the risk of fracture to the lateral cortex. Therefore the purpose of this study was to determine the effect of a pilot hole on the strains and occurrence of fractures at the lateral cortex during the opening of a high tibial osteotomy (HTO) and post-surgery loading.

Materials and Methods

A total of 14 cadaveric tibias were randomized to either a pilot hole (n = 7) or a no-hole (n = 7) condition. Lateral cortex strains were measured while the osteotomy was opened 9 mm and secured in place with a locking plate. The tibias were then subjected to an initial 800 N load that increased by 200 N every 5000 cycles, until failure or a maximum load of 2500 N.

Results

There was no significant difference in the strains on the lateral cortex during HTO opening between the pilot hole and no-hole conditions. Similarly, the lateral cortex and fixation plate strains were not significantly different during cyclic loading between the two conditions. Using a pilot hole did not significantly decrease the strains experienced at the lateral cortex, nor did it reduce the risk of fracture.

Conclusions

The nonsignificant differences found here most likely occurred because the pilot hole merely translated the stress concentration laterally to a parallel point on the surface of the hole.

Cite this article: K. Bujnowski, A. Getgood, K. Leitch, J. Farr, C. Dunning, T. A. Burkhart. A pilot hole does not reduce the strains or risk of fracture to the lateral cortex during and following a medial opening wedge high tibial osteotomy in cadaveric specimens. Bone Joint Res 2018;7:166–172. DOI: 10.1302/2046-3758.72.BJR-2017-0337.R1.

Efficacy of arthroscopic loose body removal for knee osteoarthritis

The purpose of the present study was to explore the efficacy of arthroscopic loose body removal for knee osteoarthritis (KOA). A total of 23 patients with KOA were enrolled and randomly received conservative treatment (conservative group; n=10) or loose body removal surgery (surgery group; n=13). The serum levels of disease activity indices, including hypersensitive C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR) and synovial inflammatory factors [interleukin (IL)-1 and IL-6] were detected prior to surgery, and at 4 days, 2 or 4 weeks after surgery. All patients were followed up for 2 years and the cure rate was estimated. No significant difference was identified in pre-operative plasma levels of hs-CRP and ESR as well as the synovial concentration of IL-1 and IL-6 between the two groups (all P>0.05). At 2 and 4 weeks after treatment, the levels of these parameters in the surgery group were significantly lower than those in the conservative group (all P<0.05), although the maximum value of these parameters was higher in the surgery group than in the conservative group at 4 days after surgery. The cure rate for KOA in the surgery group was significantly higher than that in the conservative group. In conclusion, the results demonstrated that arthroscopic loose body removal is a more effective treatment than conservative therapy for KOA.

Ten-year patient-reported outcomes following total and minimally invasive unicompartmental knee arthroplasty: a propensity score-matched cohort analysis

PURPOSE

For patients with medial compartment arthritis who have failed non-operative treatment, either a total knee arthroplasty (TKA) or a unicompartmental knee arthroplasty (UKA) can be undertaken. This analysis considers how the choice between UKA and TKA affects long-term patient-reported outcome measures (PROMs).

METHODS

The Knee Arthroplasty Trial (KAT) and a cohort of patients who received a minimally invasive UKA provided data. Propensity score matching was used to identify comparable patients. Oxford Knee Score (OKS), its pain and function components, and the EuroQol 5 Domain (EQ-5D) index, estimated on the basis of OKS responses, were then compared over 10 years following surgery. Mixed-effects regressions for repeated measures were used to estimate the effect of patient characteristics and type of surgery on PROMs.

RESULTS

Five-hundred and ninety UKAs were matched to the same number of TKAs. Receiving UKA rather than TKA was found to be associated with better scores for OKS, including both its pain and function components, and EQ-5D, with the differences expected to grow over time. UKA was also associated with an increased likelihood of patients achieving a successful outcome, with an increased chance of attaining minimally clinically important improvements in both OKS and EQ-5D, and an 'excellent' OKS. In addition, for both procedures, patients aged between 60 and 70 and better pre-operative scores were associated with better post-operative outcomes.

CONCLUSION

Minimally invasive UKAs performed on patients with the appropriate indications led to better patient-reported pain and function scores than TKAs performed on comparable patients. UKA can lead to better long-term quality of life than TKA and this should be considered alongside risk of revision when choosing between the procedures.

LEVEL OF EVIDENCE

II.

Mud-Bath Therapy in Addition to Usual Care in Bilateral Knee Osteoarthritis: An Economic Evaluation Alongside a Randomized Controlled Trial

OBJECTIVE

To perform a cost-effectiveness analysis of mud-bath therapy (MBT) in addition to usual treatment compared to usual treatment alone in patients with bilateral knee osteoarthritis (OA).

METHODS

An economic evaluation alongside a randomized controlled trial was conducted. Patients were randomly assigned to receive either a 2-week cycle of MBT in addition to their usual treatment or to continue routine care alone. The EuroQol 5-domain questionnaire was administered at baseline, 2 weeks, and at 3, 6, 9, and 12 months. Direct health care resource consumption data up until 12 months were derived from a daily diary given to patients and returned at prescheduled followup visits.

RESULTS

A total of 103 patients were included (n = 53 for MBT patients; n = 50 for controls). Overall, patients in the MBT group accrued mean ± SD 0.835 ± 0.10 quality-adjusted life years (QALYs) compared to 0.753 ± 0.11 in the control group (P < 0.001). Average direct costs per patient (€303 versus €975; P < 0.001) were higher in the control group, primarily because of hospitalization for total knee replacement and use of intraarticular hyaluronic acid. Bootstrapping replications of costs and QALY sample distributions consistently indicated that the MBT therapy combined with standard therapy represents a dominant strategy as compared with standard therapy alone. The probability of MBT being cost-effective at standard cost-effectiveness thresholds (e.g., €20,000/QALY) is 100%.

CONCLUSION

The results of this cost-effectiveness analysis support the use of MBT as midterm complementary therapy in the management of knee OA.

Long-term results and comparison of the three different high tibial osteotomy and fixation techniques in medial compartment arthrosis

BACKGROUND

The purpose of this study is to report and analyze the long-term outcomes of the patients who underwent high tibial osteotomy (HTO) with three different techniques for the treatment of medial compartment arthrosis.

METHODS

A total of 187 patients (195 knees) who underwent HTO between 1990 and 2010 were retrospectively evaluated. Eighty-eight knees, opening-wedge osteotomy with Puddu plate (group A); 51 knees, transverse osteotomy below the tubercle with external fixator (group B); and 29 knees, closing-wedge osteotomy with staple fixation (group C) were included in the study. The patients (mean age 44.9 ± 10.6 years, mean follow-up of 12.4 ± 3.2 years) were called for final controls and survival rates of the knees, and functional evaluations of the patients were performed using Knee Society Score (KSS) and Hospital for Special Surgery (HSS) knee score assessments.

RESULTS

In the comparison of the three groups, there were no differences regarding the mean age, preoperative arthrosis levels, or preoperative deformity analyses (n.s.). The main finding of these comparisons showed that the closing-wedge osteotomy has the greatest lateralization effect on mechanical axis deviation (MAD) (p = 0.024), the greatest valgization effect on medial proximal tibial angles (MPTA) (p = 0.026), and the lowest posterior tibial slope (PTS) angles (p = 0.032) in comparison to the other groups. There were no functional differences between the three groups in the long-term assessment of patients with KSS and HSS knee scores. According to the Kaplan-Meier survival analysis, the probability of the survival of the native knee joint after HTO was 93.4% in 5 years and 71.2% in 10 years in our study group. During the follow-up of the 168 knees, revision surgery with total knee replacement was needed in 27 knees (16%). The mean time from HTO to total knee replacement was 8.9 years in these patients.

CONCLUSIONS

HTO has acceptable long-term clinical and functional results that should not be underestimated by orthopedic surgeons under pressure to perform arthroplasty operations.

THE EUROPEAN SOCIETY FOR CLINICAL AND ECONOMIC ASPECTS OF OSTEOPOROSIS AND OSTEOARTHRITIS (ESCEO) ALGORITHM FOR THE MANAGEMENT OF KNEE OSTEOARTHRITIS IS APPLICABLE TO RUSSIAN CLINICAL PRACTICE: A CONSENSUS STATEMENT OF LEADING RUSSIAN AND ESCEO OSTEOARTHRITIS EXPERTS

The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) treatment algorithm for the management of knee osteoarthritis (OA), published in December 2014, provides practical guidance for the prioritization of interventions. This current paper represents an assessment and endorsement of the algorithm by Russian experts in OA for use in Russian clinical practice, with the aim of providing easy-to-follow advice on how to establish a treatment flow in patients with knee OA, in support of the clinicians’ individualized assessment of the patient. Medications recommended by the ESCEO algorithm are available in Russia. In step 1, background maintenance therapy with symptomatic slow-acting drugs for osteoarthritis (SYSADOA) is advised, for which high-quality evidence is provided only for the formulations of patented crystalline glucosamine sulphate (pCGS) (Rottapharm/Meda) and prescription chondroitin sulfate. Paracetamol may be added for rescue analgesia only, due to limited efficacy and increasing safety signals. Topical non-steroidal anti-inflammatory drugs (NSAIDs) may provide additional symptomatic treatment with the same degree of efficacy as oral NSAIDs but without the systemic safety concerns. To be effective, topical NSAIDs must have high bioavailability, and among NSAIDs molecules like etofenamate have high absorption and bioavailability alongside evidence for accumulation in synovial tissues. Oral NSAIDs maintain a central role in step 2 advanced management of persistent symptoms. However, oral NSAIDs are highly heterogeneous in terms of gastrointestinal and cardiovascular safety profile, and patient stratification with careful treatment selection is advocated to maximize the risk: benefit ratio. Intra-articular hyaluronic acid as a next step provides sustained clinical benefit with effects lasting up to 6 months after a short-course of weekly injections. As a last step before surgery, the slow titration of sustained-release tramadol, a weak opioid, affords sustained analgesia with improved tolerability.

Knee Osteoarthritis: A Primer

The purpose of this article is to provide a synopsis of the current medical understanding of knee osteoarthritis. We describe the prevalence, causes and associated risk factors, symptoms, diagnosis and classification, and treatment options. A quiz serves to assist readers in their understanding of the presented material.

Use of polyvinylpyrrolidone-iodine solution for sterilisation and preservation improves mechanical properties and osteogenesis of allografts

Allografts eliminate the disadvantages associated with autografts and synthetic scaffolds but are associated with a disease-transmission risk. Therefore, allograft sterilisation is crucial. We aimed to determine whether polyvinylpyrrolidone-iodine (PVP-I) can be used for sterilisation and as a new wet-preservation method. PVP-I-sterilised and preserved allografts demonstrated improved mechanical property, osteogenesis, and excellent microbial inhibition. A thigh muscle pouch model of nude mice showed that PVP-I-preserved allografts demonstrated better ectopic formation than Co₆₀-sterilised allografts (control) in vivo (P < 0.05). Furthermore, the PVP-I-preserved group showed no difference between 24 h and 12 weeks of allograft preservation (P > 0.05). PVP-I-preserved allografts showed more hydrophilic surfaces and PVP-I-sterilised tendons showed higher mechanical strength than Co₆₀-sterilised tendons (P < 0.05). The level of residual PVP-I was higher without washing and with prolonged preservation (P < 0.05). In vitro cellular tests showed that appropriate PVP-I concentration was nontoxic to preosteoblast cells, and cellular differentiation measured by alkaline phosphatase activity and osteogenic gene markers was enhanced (P < 0.05). Therefore, the improved biological performance of implanted allografts may be attributable to better surface properties and residual PVP-I, and PVP-I immersion can be a simple, easy method for allograft sterilisation and preservation.

Biological, biochemical and biomechanical characterisation of articular cartilage from the porcine, bovine and ovine hip and knee

This study aimed to determine the optimal starting material for the development of an acellular osteochondral graft. Osteochondral tissues from three different species were characterised; pig (6 months), cow (18 months) and two ages of sheep (8-12 months and >4 year old). Tissues from the acetabulum and femoral head of the hip, and the groove, medial and lateral condyles and tibial plateau of the knee were assessed. Histological analysis of each tissue allowed for qualification of cartilage histoarchitecture, glycosaminoglycan (GAG) distribution, assessment of cellularity and cartilage thickness. Collagen and GAG content were quantified and cartilage water content was defined. Following biomechanical testing, the percentage deformation, permeability and equilibrium elastic modulus was determined. Results showed that porcine cartilage had the highest concentration of sulphated proteoglycans and that the condyles and groove of the knee showed higher GAG content than other joint areas. Cartilage from younger tissues (porcine and young ovine) had higher cell content and was thicker, reflecting the effects of age on cartilage structure. Cartilage from older sheep had a much higher elastic modulus and was less permeable than other species.

Determinants of knee replacement in subjects with a history of arthroscopy: data from the osteoarthritis initiative

OBJECTIVE

To investigate the risk and determinants of knee replacement (KR) in subjects with or at risk of osteoarthritis (OA) and a history of arthroscopy.

METHODS

Data from the osteoarthritis initiative cohort were analyzed (n = 4796, up to the seventh year of follow-up). Cox proportional hazard analysis was used to determine the risk of KR according to the history of arthroscopy. A multivariable model was used to determine the risk factors for KR among subjects with a history of arthroscopy (n = 842), including age, gender, body mass index, history of knee injury, and baseline physical activity scale for the elderly, Western Ontario and McMaster (WOMAC) total score, and radiographic Kellgren and Lawrence (KL) score.

RESULTS

History of arthroscopy was associated with risk of KR after adjustments for the mentioned determinants of OA (HR: 1.90 (1.49-2.44); P value <0.001). Female gender (HR: 1.86 (1.30-2.68); P value <0.001), higher WOMAC (HR: 1.02 (1.01-1.03); P value <0.001), and KL score (HR: 2.64 (2.08-3.35); P value <0.001) increased the risk of KR among subjects with a history of arthroscopy. Subjects with a history of knee injury had 50 % lower risk of KR (HR: 0.50 (0.35-0.72); P value <0.001) after arthroscopy.

CONCLUSION

Female gender, more clinical symptoms and radiographic signs of OA, was associated with higher risk of future KR in subjects with a history of arthroscopy. Subjects with arthroscopy in the setting of concomitant knee injury were 50 % less likely to undergo KR compared to subjects who underwent arthroscopy without a history of concomitant knee injury.

Effect of Body Mass Index and Psychosocial Traits on Total Knee Replacement Costs in Patients with Osteoarthritis

Objective.

Clinical and psychosocial attributes are associated with clinical outcomes after total knee replacement (TKR) surgery in patients with osteoarthritis (OA), but their relationship with TKR-related costs is less clear. Our objective was to evaluate the effect of clinical and psychosocial attributes on TKR costs.

Methods.

We conducted a 6-month prospective cohort study of patients with knee OA who underwent TKR. We examined baseline demographic, clinical [body mass index (BMI) and comorbidities], and psychosocial attributes (social support, locus of control, coping, depression, anxiety, stress, and self-efficacy); baseline and 6-month OA clinical outcomes [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function]; and 6-month direct and indirect TKR-related costs. Multiple regression was performed to identify determinants of TKR-related costs.

Results.

We included 212 patients; 66% were women, 71% were white, and the mean age was 65.2 years. The mean baseline WOMAC pain score was 55 (SD 19) and WOMAC function score was 54 (SD 20). Mean total TKR-related costs were US$30,831 (SD $9893). Multivariate regression analyses showed that increasing BMI and anxiety levels and decreasing levels of positive social interactions were associated with increased costs. A lower cost scenario with a lower range of normal BMI (19.5), highest positive social interaction, and no anxiety predicted TKR costs to be $22,247. Predicted costs in obese patients (BMI 36) with lowest positive social interaction and highest anxiety were $58,447.

Conclusion.

Increased baseline BMI, anxiety, and poor social support lead to higher TKR-related costs in patients with knee OA. Preoperative interventions targeting these factors may reduce TKR-related costs, and therefore be cost-effective.

Chondrogenic regeneration using bone marrow clots and a porous polycaprolactone-hydroxyapatite scaffold by three-dimensional printing

Scaffolds play an important role in directing three-dimensional (3D) cartilage regeneration. Our recent study reported the potential advantages of bone marrow clots (MC) in promoting extracellular matrix (ECM) scaffold chondrogenic regeneration. The aim of this study is to build a new scaffold for MC, with improved characteristics in mechanics, shaping, and biodegradability, compared to our previous study. To address this issue, this study prepared a 3D porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffold combined with MC (Group A), while the control group (Group B) utilized a bone marrow stem cell seeded PCL-HA scaffold. The results of in vitro cultures and in vivo implantation demonstrated that although an initial obstruction of nutrient exchange caused by large amounts of fibrin and erythrocytes led to a decrease in the ratio of live cells in Group A, these scaffolds also showed significant improvements in cell adhesion, proliferation, and chondrogenic differentiation with porous recanalization in the later culture, compared to Group B. After 4 weeks of in vivo implantation, Group A scaffolds have a superior performance in DNA content, Sox9 and RunX2 expression, cartilage lacuna-like cell and ECM accumulation, when compared to Group B. Furthermore, Group A scaffold size and mechanics were stable during in vitro and in vivo experiments, unlike the scaffolds in our previous study. Our results suggest that the combination with MC proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The MC-PCL-HA scaffold is a candidate for future cartilage regeneration studies.

Return to sports, recreational activity and patient-reported outcomes after lateral unicompartmental knee arthroplasty

PURPOSE

As the indication for unicompartmental knee arthroplasty (UKA) in recent years has been extended to young and more active patients, the expectations concerning the postoperative level of activity are high. The aim of the following study was to survey the activity level and the health-related quality of life of patients following lateral UKA.

METHODS

Forty-five patients were surveyed to determine their sporting and recreational activities at a mean follow-up of 3 years (range 2.0-4.3 years) after lateral UKA. We also assessed health-related quality of life of our patients at the time of the survey by use of the SF-36 Health Survey.

RESULTS

Before the onset of the first restricting symptoms, 42 of 45 (93 %) patients were active in at least one sport compared to 43 of 45 (96 %) patients after surgery resulting in a return to activity rate of 98 %. Within 3 months, 56 % returned to their activities after surgery and 78 % within 6 months. The mean postoperative UCLA score was 6.7 (±1.5). Two-thirds of the patients reached a high activity level (UCLA ≥7). Most common activities after surgery were biking, hiking and long walks. While high-impact activities showed a significant decrease, low-impact activities showed a significant increase. The main reason for a decrease in patients' level of activity was precaution. There are no statistically significant differences in the postoperative scores of our patients and those of a matched healthy reference population in the SF-36 scores.

CONCLUSION

The results of the present study demonstrate that a vast majority (98 %) of our patients independent to age or gender returned to sports and recreational activity after lateral UKA. Two-thirds of the patients reached a high activity level. Activities patients were most participating in were low- or mid-impact, whereas high-impact activities were mostly given up. Further follow-up is necessary to assess the effect of activity on implant fixation and wear.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Fibrous Scaffolds with Varied Fiber Chemistry and Growth Factor Delivery Promote Repair in a Porcine Cartilage Defect Model

Current clinically approved methods for cartilage repair are generally based on either endogenous cell recruitment (e.g., microfracture) or chondrocyte delivery (e.g., autologous chondrocyte implantation). However, both methods culminate in repair tissue with inferior mechanical properties and the addition of biomaterials to these clinical interventions may improve their efficacy. To this end, the objective of this study was to investigate the ability of multipolymer acellular fibrous scaffolds to improve cartilage repair when combined with microfracture in a large animal (i.e., minipig) model. Composite scaffolds were formulated from a combination of hyaluronic acid (HA) fibers and poly(ɛ-caprolactone) (PCL) fibers, either with or without transforming growth factor-β3 (TGFβ3). After 12 weeks in vivo, material choice and TGFβ3 delivery had a significant impact on outcomes; specifically, PCL scaffolds without TGFβ3 had inferior gross appearance and reduced mechanical properties, whereas HA scaffolds that released TGFβ3 resulted in improved histological scores and increased type 2 collagen content. Importantly, analysis of the overall dataset revealed that histology, but not gross appearance, was a better predictor of mechanical properties. This study highlights the importance of scaffold properties on in vivo cartilage repair as well as the need for numerous quantitative outcome measures to fully evaluate treatment methods.

Recommendations for the conduct of efficacy trials of treatment devices for osteoarthritis: a report from a working group of the Arthritis Research UK Osteoarthritis and Crystal Diseases Clinical Studies Group

OBJECTIVE

There are unique challenges to designing and carrying out high-quality trials testing therapeutic devices in OA and other rheumatic diseases. Such challenges include determining the mechanisms of action of the device and the appropriate sham. Design of device trials is more challenging than that of placebo-controlled drug trials. Our aim was to develop recommendations for designing device trials.

METHODS

An Arthritis Research UK study group comprised of 30 rheumatologists, physiotherapists, podiatrists, engineers, orthopaedists, trialists and patients, including many who have carried out device trials, met and (using a Delphi-styled approach) came to consensus on recommendations for device trials.

RESULTS

Challenges unique to device trials include defining the mechanism of action of the device and, therefore, the appropriate sham that provides a placebo effect without duplicating the action of the active device. Should there be no clear-cut mechanism of action, a three-arm trial including a no-treatment arm and one with presumed sham action was recommended. For individualized devices, generalizable indications and standardization of the devices are needed so that treatments can be generalized.

CONCLUSION

A consensus set of recommendations for device trials was developed, providing a basis for improved trial design, and hopefully improvement in the number of effective therapeutic devices for rheumatic diseases.

Cartilage matrix changes in contralateral mobile knees in a rabbit model of osteoarthritis induced by immobilization

Background

Many researches have investigated the changes associated with immobilization-induced osteoarthritis (OA). However, there are only few studies focusing on the effect of unilateral knee immobilization on cartilage matrix changes in the contralateral mobile knee. The aim of the present study was to investigate the influence of immobilization on the cartilage matrix in the contralateral mobile knees in a rabbit model of OA induced by immobilization.

Methods

Right knees (experimental knees) of eighteen mature female rabbits were immobilized at an extension of 180° with orthopedic casting tape for 2, 4, or 8 weeks. Left knees (contralateral knees) of the immobilized rabbits were not subjected to immobilization. The knees of six non-immobilized rabbits were designated as control knees. Following immobilization, cartilage specimens from the medial femoral condyle underwent macroscopic, histological, immunohistochemical, and biochemical evaluations.

Results

Roughness of cartilage surface was detected in the experimental knees at 2 weeks, and cartilage degeneration was further developed. In the contralateral knee, cartilage showed degenerative changes after 4 weeks. Safranin-O staining and glycosaminoglycan (GAG) contents were reduced in the experimental knees following immobilization and in the contralateral intact knees after 4 and 8 weeks. Type II collagen staining was gradually reduced, type I collagen accumulation was obviously detected in the upper and middle layers of cartilage in experimental knees after 8 weeks, and the collagen orientation was gradually disorganized in both knees at 4 and 8 weeks. For both experimental and contralateral knees, collagen contents were significantly decreased at 8 weeks, and Mankin and Osteoarthritis Research Society International (OARSI) scores increased over time.

Conclusion

OA developed in the contralateral intact knee with the progress of OA in the immobilized knee in a rabbit model of immobilization-induced OA.

Using 7.0T MRI T2 mapping to detect early changes of the cartilage matrix caused by immobilization in a rabbit model of immobilization-induced osteoarthritis

OBJECTIVE

The goal of this study was to detect early changes in the cartilage matrix caused by immobilization in a rabbit model of immobilization-induced osteoarthritis (OA) by T2 mapping with 7.0T MRI.

MATERIALS AND METHODS

Left knee joints of 28 mature rabbits were immobilized at 180° of extension with orthopedic casting tape for 1, 2, or 3weeks (n=7 rabbits each). No immobilization was performed in the control group (n=7 rabbits). T2 mapping was performed after 1, 2, and 3weeks. Osteochondral specimens harvested from the trochlea groove (TG) and medial femoral condyle (MFC) were subjected to histologic, immunohistochemical, and microscopic evaluation, followed by biochemical assays for water, glycosaminoglycan (GAG), and collagen. The ability of T2 mapping to reveal changes in the cartilage matrix was further assessed.

RESULTS

Rabbits demonstrated elevated T2 values (9.9% in TG, 10.6% in MFC), a dulled cartilage surface, reduced Safranin-O staining, and decreased GAG content (14.2% in TG and MFC) after 2weeks, with cartilage surface softening, irregularity, and markedly reduced GAG content by 3weeks. T2 values were correlated positively with water (r=0.836 in TG, r=0.821 in MFC) and negatively with GAG content (r=-0.945 in TG, r=-0.957 in MFC), but had no discernible relationship with collagen content (r=-0.196 in TG, r=-0.213 in MFC).

CONCLUSIONS

7.0T MRI T2 mapping can be used to detect early changes of the cartilage matrix caused by immobilization in an immobilization-induced OA model.

Arthroscopic patelloplasty and circumpatellar denervation for the treatment of patellofemoral osteoarthritis

BACKGROUND

Patellofemoral osteoarthritis commonly occurs in older people, often resulting in anterior knee pain and severely reduced quality of life. The aim was to examine the effectiveness of arthroscopic patelloplasty and circumpatellar denervation for the treatment of patellofemoral osteoarthritis (PFOA).

METHODS

A total of 156 PFOA patients (62 males, 94 females; ages 45-81 years, mean 66 years) treated in our department between September 2012 and March 2013 were involved in this study. Clinical manifestations included recurrent swelling and pain in the knee joint and aggravated pain upon ascending/descending stairs, squatting down, or standing up. PFOA was treated with arthroscopic patelloplasty and circumpatellar denervation. The therapeutic effects before and after surgery were statistically evaluated using Lysholm and Kujala scores. The therapeutic effects were graded by classification of the degree of cartilage defect.

RESULTS

A total of 149 cases were successfully followed up for 14.8 months, on average. The incisions healed well, and no complications occurred. After surgery, the average Lysholm score improved from 73.29 to 80.93, and the average Kujala score improved from 68.34 to 76.48. This procedure was highly effective for patients with cartilage defects I-III but not for patients with cartilage defect IV.

CONCLUSIONS

For PFOA patients, this procedure is effective for significantly relieving anterior knee pain, improving knee joint function and quality of life, and deferring arthritic progression.

Poly(2-ethyl-(2-pyrrolidone) methacrylate) and hyaluronic acid–based hydrogels for the engineering of a cartilage-like tissue using bovine articular chondrocytes

Poly(2-ethyl-(2-pyrrolidone)methacrylate)–hyaluronic acid hydrogels based on the free radical polymerization of 2-ethyl-(2-pyrrolidone)methacrylate combined with hyaluronic acid, using N,N′-methylenebisacrylamide or triethylene glycol dimethacrylate, as cross-linking agents, were considered for tissue engineering applications. Bovine articular chondrocytes were seeded onto the poly(2-ethyl-(2-pyrrolidone)methacrylate)–hyaluronic acid hydrogels, under orbital agitation, for a total of 40 days. The engineered cell-constructs were characterized according to cell proliferation, morphology and distribution as well as the biochemical composition of the tissue formed. The chondrocytes were found to be attached and presented a typical spherical morphology. Cells were able to proliferate and synthesize a hyaline-like matrix rich in glycosaminoglycans and collagen type II which were mainly located on the superficial area. Increased content of individual components poly(2-ethyl-(2-pyrrolidone)methacrylate) and hyaluronic acid, in triethylene glycol dimethacrylate–cross-linked networks led to enhanced cell distribution and total glycosaminoglycans content, supporting their potential application for the repair of cartilaginous tissues.

Naproxen induces type X collagen expression in human bone-marrow-derived mesenchymal stem cells through the upregulation of 5-lipoxygenase

Several studies have shown that type X collagen (COL X), a marker of late-stage chondrocyte hypertrophy, is expressed in mesenchymal stem cells (MSCs) from osteoarthritis (OA) patients. We recently found that Naproxen, but not other nonsteroidal anti-inflammatory drugs (NSAIDs) (Ibuprofen, Celebrex, Diclofenac), can induce type X collagen gene (COL10A1) expression in bone-marrow-derived MSCs from healthy and OA donors. In this study we determined the effect of Naproxen on COL X protein expression and investigated the intracellular signaling pathways that mediate Naproxen-induced COL10A1 expression in normal and OA hMSCs. MSCs of OA patients were isolated from aspirates from the intramedullary canal of donors (50-80 years of age) undergoing hip replacement surgery for OA and were treated with or without Naproxen (100 μg/mL). Protein expression and phosphorylation were determined by immunoblotting using specific antibodies (COL X, p38 mitogen-activated protein kinase [p38], phosphorylated-p38, c-Jun N-terminal kinase [JNK], phosphorylated-JNK, extracellular signal-regulated kinase [ERK], and phosphorylated-ERK). Real-time reverse transcription polymerase chain reaction (RT-PCR) was performed to determine the expression of COL10A1 and Runt-related transcription factor 2 gene (Runx2). Our results show that Naproxen significantly stimulated COL X protein expression after 72 h of exposure both in normal and OA hMSCs. The basal phosphorylation of mitogen-activated protein kinases (MAPKs) (ERK, JNK, and p38) in OA hMSCs was significantly higher than in normal. Naproxen significantly increased the MAPK phosphorylation in normal and OA hMSCs. NSAID cellular effects include cyclooxygenase, 5-lipoxygenase, and p38 MAPK signaling pathways. To investigate the involvement of these pathways in the Naproxen-induced COL10A1 expression, we incubated normal and OA hMSCs with Naproxen with and without inhibitors of ERK (U0126), JNK (BI-78D3), p38 (SB203580), and 5-lipoxygenase (MK-886). Our results showed that increased basal COL10A1 expression in OA hMSCs was significantly suppressed in the presence of JNK and p38 inhibitors, whereas Naproxen-induced COL10A1 expression was suppressed by 5-lipoxygenase inhibitor. This study shows that Naproxen induces COL X both at transcriptional and translational levels in normal and OA hMSCs. Elevated basal COL10A1 expression in OA hMSCs is probably through the activation of MAPK pathway and Naproxen-induced COL10A1 expression is through the increased 5-lipoxygenase signaling.