Meniscus Lesions Tied to Neuropathic Pain in Knee OA
Friday, January 30, 2015 10:10 PM

Meniscus lesions, specifically extrusions, were a risk factor for neuropathic pain in patients with knee osteoarthritis (OA), results of a pilot study suggested.  The presence of meniscal extrusion on MRI, in both medial and lateral compartments, was significantly associated with increasing neuropathic pain (NP) pain scores in knee OA patients.  The presence of meniscal tears in the lateral compartment was also significantly associated with pain scores the study reports.

"Our finding of an association between neuropathic pain (NP) and lateral meniscal tear is somewhat unexpected as literature indicates that meniscal tears are not usually associated with symptoms," the authors wrote.

The multicenter, cross-sectional, observational study included 50 patients with symptomatic knee OA who had moderate to severe pain in the most painful knee.

The finding of a greater likelihood of NP in patients with meniscal extrusion and lateral meniscal tears suggests that knee OA patients with a neuropathic pain component have more severe symptoms, they wrote. This, to a certain extent, was reflected by a trend towards greater use of non-steroidal anti-inflammatory drugs (NSAIDS), they added.

The exact mechanisms underlying neuropathic pain-like symptoms in OA are poorly understood, but the authors noted that OA pain likely includes both nociceptive and neuropathic components. It has been suggested that local damage to innervation as well as other joint structures may cause damage to peripheral nerves, they said.  There are very few data on the relationship between meniscal lesions and NP in knee OA, they commented, noting that this is a promising field of future research.

This finding is clinically relevant for various reasons, they added. Not only does it support the examination for meniscal extrusion in knee OA patients with neuropathic pain, but the predominance of a neuropathic component in such patients should encourage physicians to consider using MRI to establish a proper diagnosis.

A diagnosis of meniscal extrusion may also help identify patients who might benefit from treatment aimed at controlling their symptoms. "There is hope that this 'personalized therapeutic management' would avoid the prolonged use of anti-inflammatory drugs or even narcotic analgesics, preventing potential side effects" the authors wrote.