Can radiological findings detect neuropathic pain in patients with osteoarthritis of the knee undergoing surgery?

OBJECTIVES: The mechanism underlying neuropathic pain (NP) in osteoarthritis (OA) of the knee is not completely understood. This study aimed to investigate whether possible NP in patients with knee OA undergoing knee surgery is associated with specific radiological findings. METHODS: This study included 197 patients who underwent knee surgery for symptomatic knee OA. Clinical evaluation was performed using the Central Sensitization Inventory (CSI), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and PainDETECT questionnaire. Radiological evaluation was performed using the hip-knee-ankle (HKA) angle, posterior tibial slope (PTS), varus and valgus laxities, and magnetic resonance imaging OA Knee Score (MOAKS). Radiological findings were compared between patients with possible and unlikely NP. Logistic regression analysis was performed to identify the predictive factors for NP. RESULTS: There were 163 and 34 patients with unlikely NP and with possible NP, respectively. The percentage of patients with CSI score ≥ 40 was significantly higher in the possible NP group than in the unlikely NP group (17.6% vs. 6.1%). Patients with possible NP had worse WOMAC scores than patients with unlikely NP. There were no significant positive associations between the possible NP and radiological findings in knee OA. Regression analysis showed no predictive factors for possible NP. CONCLUSIONS: Possible NP is not associated with specific radiological findings in knee OA. Patients with possible NP may mediate CS and experience more severe symptoms, including decreased knee function and lower quality of life, than patients with unlikely NP.

Comparison of Clinical and Imaging Outcomes of Different Doses of Adipose-Derived Stromal Vascular Fraction Cell Treatment for Knee Osteoarthritis.

Favorable clinical outcomes of intra-articular injection of adipose-derived stromal vascular fraction (SVF) cells for knee osteoarthritis (OA) have been reported, but the effects of different doses of SVF cells have not been examined. This study aimed to compare the short-term clinical and imaging outcomes of different doses of SVF cells for knee OA treatment. This study included 60 patients with knee OA who underwent intra-articular injection of SVF cells. The follow-up period was at least 12 months. Thirty patients received an intra-articular injection of 2.5×107 SVF cells (low-dose group), and the remaining 30 patients received an intra-articular injection of 5.0×107 SVF cells (high-dose group). Clinical evaluations were performed for the Knee injury and Osteoarthritis Outcome Score (KOOS). Imaging evaluations, including the magnetic resonance imaging Osteoarthritis Knee Score (MOAKS) features (bone marrow lesions, cartilage defects, osteophytes, Hoffa's synovitis, and effusion synovitis), were also performed. All clinical and imaging evaluations were performed preoperatively and 12 months postoperatively and compared between the groups. In demographic data, no significant differences were found between the two groups. The total score of KOOS at 12 months postoperatively was significantly more favorable than the preoperative score in the high-dose groups. Pain and symptoms subscale scores of KOOS at 12 months postoperatively were significantly better in the high-dose group than in the low-dose group. The bone marrow lesions, Hoffa's synovitis, and effusion synovitis improved approximately 30-40% at 12 months postoperatively compared to baseline in both groups. However, there were no significant differences in imaging evaluations between the two groups. In conclusion, the pain and symptoms subscale scores of KOOS from baseline to 12 months postoperatively improved better in the high-dose group than in the low-dose group. Our findings suggest that intra-articular injection of SVF cells for knee OA is an innovative approach.

Dolor en la artrosis de rodilla / Pain in knee osteoarthritis

El dolor constituye el síntoma fundamental de la artrosis, sus características e interpretación permiten el diagnóstico certero y también conocer la magnitud de esa entidad. El objetivo de este trabajo, es profundizar los conocimientos sobre los elementos más esenciales relacionados con el dolor en la artrosis de la rodilla. Se describen las causas mecánicas y bioquímicas del dolor, entre las que resaltan el dolor óseo, sinovial, así como los factores bioquímicos relacionados con ese síntoma. Se hace referencia a las principales estructuras anatómicas responsables del dolor y sus mecanismos de acción. Se mencionan la relación existente entre ese síntoma y las modalidades imagenológicas, así como los patrones del dolor. Para finalizar, se hace referencia a las escalas de dolor usadas.

Pain is the main symptom of osteoarthritis. Determining the distinctive features of pain in knee osteoarthritis allows for an accurate diagnosis. This article gives a review of the results from research work on the typical features of knee osteoarthritic pain. The mechanics and biochemical causes of pain are described including both bone and synovial biochemical symptom-related factors. The relationships between knee pain, various imaging techniques and pain mechanism are also identified. Finally, the used pain scales are presented.