Phenotyping and Management of Knee Osteoarthritis

Knee osteoarthritis is a multifactorial condition marked by progressive cartilage loss, subchondral bone remodelling and chronic pain. Heterogeneity in structural changes, inflammatory activity and pain perception has prompted the delineation of distinct clinical and molecular phenotypes. Commonly recognised phenotypes include mechanical overload driven by malalignment, inflammatory characterised by elevated cytokine activity, metabolic associated with obesity and lipid dysregulation, bone and cartilage metabolism with matrix turnover imbalance, central pain sensitisation and minimal joint disease with slow progression. Precise phenotyping enables stratification of patients for tailored interventions, ranging from targeted anti-inflammatory agents and neuromodulatory strategies to biomechanical realignment and weight-management programmes. Advances in imaging techniques, synovial fluid and serum biomarkers, and machine-learning analyses facilitate identification of subgroups most likely to benefit from specific therapies. Integrating phenotypic profiles with patient-centred management pathways holds promise for improving functional outcomes, reducing symptom burden and optimising resource allocation on a global scale.

Research from Nature Portfolio

Latent profile analysis applied to a large cohort of individuals with knee osteoarthritis revealed four discrete subgroups defined by body mass index, radiographic severity, pain catastrophising, self-efficacy and disturbed knee self-perception. Clusters ranged from early radiographic changes with moderate symptoms to advanced joint damage accompanied by profound cognitive and perceptual dysfunction. Importantly, cognitive factors and altered body perception explained discrepancies between radiographic severity and disability, underscoring the need to incorporate psychological and sensorimotor assessments into phenotype-driven management plans.

Phenotyping and Management of Knee Osteoarthritis publication trend

The graph below shows the total number of articles in phenotyping and management of knee osteoarthritis across all publications each year (not limited to Nature Index journals).

Technical terms

Phenotype: A subgroup of patients sharing distinct underlying mechanisms, such as inflammatory, metabolic or pain-sensitisation pathways.

Cytokine: A small protein secreted by immune or joint cells that modulates inflammation and tissue remodelling.

Synovial fluid: The lubricating liquid within the joint capsule, analysed for biomarkers of inflammation and cartilage turnover.

Latent profile analysis: A statistical technique that identifies unobserved subgroups within a population based on multiple variables.

Stratified exercise therapy: A treatment approach in which patients are allocated to exercise programmes tailored to their specific phenotype or functional capacity.

References

1. Recent advances in understanding the phenotypes of osteoarthritis. F1000Research (2019).
2. Knee-related disability was largely influenced by cognitive factors and disturbed body perception in knee osteoarthritis. Scientific Reports (2021).
3. Specific-cytokine associations with outcomes in knee osteoarthritis subgroups: breaking down disease heterogeneity with phenotyping. Arthritis Research & Therapy (2024).
4. Biclustering reveals potential knee OA phenotypes in exploratory analyses: Data from the Osteoarthritis Initiative. PLOS ONE (2022).
5. Stratified exercise therapy compared with usual care by physical therapists in patients with knee osteoarthritis: A randomized controlled trial protocol (OCTOPuS study). Environmental Quality Management (2019).