Pain trajectory defines knee osteoarthritis subgroups: a prospective observational study

Area of Science:

• Rheumatology
• Orthopedics
• Pain Medicine

Background:

• Knee osteoarthritis (OA) is a complex condition with varied patient experiences.
• Identifying distinct OA subgroups is crucial for targeted treatment and drug development.

Purpose of the Study:

• To identify homogeneous knee OA subgroups/phenotypes based on pain trajectories over time.
• To examine the relationship between pain and functional limitations in OA.
• To investigate how different OA subgroups respond to pharmacological and surgical interventions.

Main Methods:

• Group-based trajectory modeling was applied to pain data from the VIDEO trial and Osteoarthritis Initiative cohort.
• Dual trajectories were fitted to assess the interplay between pain and functional limitation.
• Analgesic use and knee replacement were analyzed in relation to identified OA phenotypes.

Main Results:

• Four distinct knee OA pain phenotypes were identified: low-fluctuating, mild-increasing, moderate-treatment-sensitive, and severe-treatment-insensitive.
• Functional knee limitation closely mirrored pain trajectories, with 94.3% concordance.
• Specific phenotypes showed differential responses to treatments, including one severe pain group unresponsive to current therapies and another likely to benefit from knee replacement.

Conclusions:

• Knee OA phenotypes can be reliably identified using longitudinal pain data, enabling better patient stratification.
• This robust and reproducible methodology informs clinical decision-making regarding symptom management and treatment options.
• The findings support a personalized medicine approach for knee osteoarthritis, optimizing therapeutic strategies.