Neuropathic-like knee pain (NKP) may be driven by central risk factors that include depression, anxiety, and pain catastrophizing, indicating that NKP may require different prevention and treatment strategies from non-neuropathic knee pain, according to a study published in Arthritis Research & Therapy.
The study included participants age ≥40 who completed a postal questionnaire to assess knee pain severity using a numeric rating scale and type — neuropathic vs nociceptive with the modified painDETECT questionnaire — as well as age, body mass index (BMI), significant knee injury, widespread pain, pain catastrophizing, and fatigue.
Of 9506 participants, 28.2% reported knee pain; 13.65% had NKP (3.9% of all responders). Women were found to be more likely than men to report NKP. After adjusting for age, gender, BMI, and pain severity, NKP was found to be associated with fibromyalgia (adjusted odds ratio [aOR], 4.07; 95% CI, 2.49-6.66), widespread pain (aOR, 1.93; 95% CI, 1.46-2.53), nodal osteoarthritis (aOR, 1.80; 95% CI, 1.28-2.53), injury (aOR, 1.50; 95% CI, 1.12-2.00), pain catastrophizing (aOR, 5.37; 95% CI, 2.93-9.84) and fatigue (aOR, 5.37; 95% CI, 3.08-9.35)
The results indicate that central and peripheral risk factors contributed equally to non-NKP (proportional risk contribution [PRC], 10%; 95% CI, 5-20 for both), and that only central risk factors contributed to NKP (central risk factors: PRC, 8%; 95% CI, 2.5-12.5 vs peripheral risk factors: PRC, 3%; 95% CI, −0.25-7.5).
“Consideration of NKP characteristics and the balance of central vs peripheral risk factors in individuals with [knee pain] could help direct best treatment selection and optimize patient care,” the researchers wrote.
Fernandes GS, Valdes AM, Walsh DA, et al. Neuropathic-like knee pain and associated risk factors: a cross-sectional study in a UK community sample. [published online September 27, 2018]. Arthritis Res Ther. doi:10.1186/s13075-018-1717-6