Background: Knee osteoarthritis (OA) is a painful condition with peripheral and central
pain transmission. Fibromyalgia (FM) is the role model of central sensitization of pain
perception.
Aim: To assess the frequency of FM in knee OA patients and evaluate the impact of FM on
mental health and the quality of life in knee OA patients.
Patients and Methods: A total of 121 female patients were recruited and divided into
3 groups: group I of 59 patients with knee OA only, group II of 32 patients with knee OA and
FM, and group III of 30 FM patients. Patients underwent history taking, examination,
investigations, and radiological evaluation of both knees. The assessment of visual analog
scale (VAS), Pittsburgh Sleep Quality Index (PSQI), Pain Anxiety Symptom Scale Short
Form 20 (PASS20), Beck Depression Inventory (BDI-II), and PCASEE questionnaire were
done for all patients. Lequesne index of knee OA and radiological Kellgren and Lawrence
score severity were done for all OA patients. Fibromyalgia Impact Questionnaire (FIQ) was
assessed for all FM patients.
Results: FM was diagnosed in 35.5% of knee OA patients. Group II patients had higher
VAS, PASS-20, PSQI, and lower quality of life than either groups I and III, elevated
Lequesne index score than group I, significant correlation between VAS and BMI
(p=0.002), Lequesne index score (p