Common Biochemical and Magnetic Resonance Imaging Biomarkers of Early Knee Osteoarthritis and of Exercise/Training in Athletes: A Narrative Review

Arthroscopic Management of Moderate-to-Severe Osteoarthritis of the Knee: A Systematic Review

BACKGROUND

Total knee arthroplasty (TKA) is the procedure of choice for osteoarthritis of the knee (OAK) when conservative treatment fails; however, high rates of dissatisfaction and poor implant longevity dissuade younger patients from TKA. There is a paucity of evidence that report outcomes and clinical effectiveness of arthroscopic knee procedures in patients with end-stage (grade 3-4) OAK. The purpose of this systematic review was to evaluate the efficacy of arthroscopic treatment for patients with moderate-to-severe (grade 3-4) OAK.

METHODS

A systematic review of the literature was performed with the terms "Knee," "Osteoarthritis," and/or "Arthroscopic debridement," "Arthroscopic lavage," "Arthroscopic microfracture," "Arthroscopic chondroplasty," "debridement," "lavage," "chondroplasty," "microfracture," and/or "arthroscopy" in PubMed (MEDLINE), Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases in November 2023 according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Databases were searched for studies that evaluated outcomes (e.g., pain, function, and conversion to TKA) for patients with Kellgren-Lawrence grade 3 to 4 OAK after knee arthroscopy (including debridement, lavage, microfracture, or chondroplasty) at a minimum 6-month follow-up. Percent improvement from preoperative score was the primary outcome measure. Secondary outcome measures included achievement of minimal clinically importance difference and conversion to TKA.

RESULTS

Nine studies (410 knees with grades 3-4 OAK) were included. Arthroscopic debridement and lavage resulted in a 18.8% to 53.1% improvement at short-term follow-up (e.g., 6 months to 3 years) and a 50.0% improvement at long-term follow-up (e.g., 10 years) in knees with grade 3 OAK and a 15.0% to 41.3% improvement at short-term follow-up and a 46.9% improvement at long-term follow-up in knees with grade 4 OAK. Arthroscopic debridement and microfracture resulted in 1.6% to 50.8% improvement at short-term follow-up in knees with grade 3 OAK. No studies included long-term outcomes or evaluated knees with grade 4 OAK after arthroscopic debridement and microfracture. Conversion to TKA after arthroscopic debridement and lavage occurred in 21.9% of patients with grade 3 OAK and in 35.0% of patients with grade 4 OAK at short-term follow-up and in 47.4% of patients with grade 3 OAK and in 76.5% of patients with grade 4 OAK at long-term follow-up. Conversion to TKA after arthroscopic debridement and microfracture occurred in 10.9% of patients with grade 3 and 4 OAK at long-term follow-up.

CONCLUSION

Arthroscopic debridement, lavage, and microfracture can provide short- and long-term symptomatic relief and improvement in function by up to 50.0% in patients with grade 3 to 4 OAK. These procedures may result in fewer patients with grade 3 OAK undergoing TKA compared with patients with grade 4 OAK.

LEVEL OF EVIDENCE

Level IV; systematic review of Level II-IV studies. See Instructions for Authors for a complete description of levels of evidence.

Therapeutic Potential of Olfactory Ensheathing Cells and Adipose-Derived Stem Cells in Osteoarthritis: Insights from Preclinical Studies

Olfactory-ensheathing cells (OECs) are known for their role in neuronal regeneration and potential to promote tissue repair. Adipose-derived stem cells (ADSCs), characterized by mesenchymal stem cell (MSC) traits, display a fibroblast-like morphology and express MSC surface markers, making them suitable for regenerative therapies for osteoarthritis (OA). In this study, OECs and ADSCs were derived from tissues and characterized for their morphology, surface marker expression, and differentiation capabilities. Collagenase-induced OA was created in 10-week-old C57BL/6 mice, followed by intra-articular injections of ADSCs (1 × 105), OECs (1 × 105), or a higher dose of OECs (5 × 105). Therapeutic efficacy was evaluated using rotarod performance tests, MRI, histology, and immunohistochemistry. Both cell types exhibited typical MSC characteristics and successfully differentiated into adipocytes, osteoblasts, and chondrocytes, confirmed by gene expression and staining. Transplantation significantly improved rotarod performance and preserved cartilage integrity, as seen in MRI and histology, with reduced cartilage destruction and increased chondrocytes. Immunohistochemistry showed elevated type II collagen and aggrecan in treated joints, indicating hyaline cartilage formation, and reduced MMP13 and IL-1β expression, suggesting decreased inflammation and catabolic activity. These findings highlight the regenerative potential of OECs and ADSCs in treating OA by preserving cartilage, promoting chondrocyte proliferation, and reducing inflammation. Further research is needed to optimize delivery methods and evaluate long-term clinical outcomes.

Molecular Assessment of Healthy Pathological Articular Cartilages in Physically Active People: A Scoping Review

Physiological aging triggers a cascade of negative effects on the human body and the human joint is only one of the several compartments affected by this irreversible and natural process. Osteoarthritis and cartilage degeneration can cause pain and disability; therefore, identifying the molecular processes underlying these phenomena and the biomarkers produced during physical activity is of critical importance. In the present review, the main goal was to identify and discuss the articular cartilage biomarkers analyzed in studies in which physical or sports activities were adopted and eventually to propose a standard operating procedure for the assessment. Articles collected from Pubmed, Web of Science, and Scopus were scrutinized to detect reliable cartilage biomarkers. The principal articular cartilage biomarkers detected in these studies were cartilage oligomeric matrix protein, matrix metalloproteinases, interleukins, and carboxy-terminal telopeptide. The articular cartilage biomarkers identified in this scoping review may aid in a better comprehension of where research on the topic is heading and offer a viable instrument for streamlining investigations on cartilage biomarker discovery.

Dose-response relationship of in vivo ambulatory load and mechanosensitive cartilage biomarkers-The role of age, tissue health and inflammation: A study protocol

OBJECTIVE

To describe a study protocol for investigating the in vivo dose-response relationship between ambulatory load magnitude and mechanosensitive blood markers of articular cartilage, the influence of age, cartilage tissue health and presence of inflammation on this relationship, and its ability to predict changes in articular cartilage quality and morphology within 2 years.

DESIGN

Prospective experimental multimodal (clinical, biomechanical, biological) data collection under walking stress and three different load conditions varied in a randomized crossover design.

EXPERIMENTAL PROTOCOL

At baseline, equal numbers of healthy and anterior cruciate ligament injured participants aged 20-30 or 40-60 years will be assessed clinically and complete questionnaires regarding their knee health. Biomechanical parameters (joint kinetics, joint kinematics, and surface electromyography) will be recorded while performing different tasks including overground and treadmill walking, single leg balance and hopping tasks. Magnetic resonance images (MRI) of both of knees will be obtained. On separate stress test days, participants will perform a 30-minute walking stress with either reduced (80% body weight (BW)), normal (100%BW) or increased (120%BW) load. Serum blood samples will be taken immediately before, immediately after, 30, 120 and 210 minutes after the walking stress. Concentration of articular cartilage blood biomarkers will be assessed using enzyme linked immunosorbent assays. At 24-month follow-up, participants will be again assessed clinically, undergo an MRI, complete questionnaires, and have a blood sample taken.

CONCLUSION

The study design provides a standardized set up that allows to better understand the influence of ambulatory load on articular cartilage biomarkers and thereby extend current knowledge on in vivo cartilage metabolism and mechanosensitivity. Further, this study will help to elucidate the prognostic value of the load-induced cartilage biomarker response for early articular cartilage degeneration.

TRIAL REGISTRATION

The protocol was approved by the regional ethics committee and has been registered at clinicaltrials.gov (NCT04128566).

Blood and urine biomarkers in osteoarthritis - an update on cartilage associated type II collagen and aggrecan markers

PURPOSE OF REVIEW

Osteoarthritis (OA) is a painful disease for which drug development has proven difficult. One major reason for this is the heterogeneity of the disease and the current lack of operationalized means to distinguish various disease endotypes (molecular subtypes). Biomarkers measured in blood or urine, reflecting joint tissue turnover, have been developed and tested during the last decades. In this narrative review, we provide highlights on biomarkers derived from the two most studied and abundant cartilage proteins - type II collagen and aggrecan.

RECENT FINDINGS

Multiple biomarkers assessing type II collagen degradation and formation, and aggrecan turnover have been developed. Several markers, such as uCTX-II, have been validated for their association with disease severity and prognosis, as well as pharmacodynamically used to describe the mode of action and efficacy of drugs in development. There is a great need for biomarkers for subdividing patients (i.e., endotyping) and recent scientific advances have not yet come closer to achieving this goal.

SUMMARY

There is strong support for using biomarkers for understanding OA, reflecting degradation and formation of the joint tissues, focused on type II collagen and aggrecan. There is still a lack of in vitro diagnostics, in all contexts of use.