Central sensitization in osteoarthritic knee pain: A cross-sectional study.

Area of Science:

• Rheumatology
• Pain Medicine
• Clinical Neuroscience

Background:

• Central sensitization (CS) is a key mechanism in chronic pain conditions.
• Understanding CS in knee osteoarthritis (OA) and rheumatoid arthritis (RA) is crucial for effective management.
• Factors associated with CS in these patient groups require further investigation.

Purpose of the Study:

• To investigate central sensitization and its associated factors in knee osteoarthritis (OA) patients.
• To compare central sensitization between OA patients, rheumatoid arthritis (RA) patients with knee pain, and healthy controls.

Main Methods:

• A cross-sectional study involving 125 participants (62 OA, 32 RA, 31 controls).
• Central sensitization assessed using the Central Sensitization Inventory (CSI) and pressure pain threshold (PPT) measurements.
• Pain, functional status, and psychosocial features evaluated via self-reported questionnaires.

Main Results:

• Both OA and RA groups exhibited significantly lower PPT values compared to controls, indicating heightened pain sensitivity.
• Pressure hyperalgesia was prevalent in OA (43.5% knee) and RA (37.5% knee) patients.
• No significant differences in PPT values, CSI scores, or CS frequency were found between OA and RA groups.
• Psychosocial factors and structural damage did not correlate with PPT in OA patients.

Conclusions:

• Central sensitization is a common feature in both knee OA and RA.
• Clinical indicators for recognizing central sensitization in OA patients include chronic pain severity and functional status.
• Local joint damage is not a primary driver of central sensitization in OA; persistent pain is the key association.