Does Advanced Osteoarthritis Mimic Neuropathic Joint?

Osteoarthritis (OA) is a prevalent condition among the elderly and leads to pain and functional limitations. Radiographic imaging often fails to correlate with symptom severity, and advanced OA may exhibit features reminiscent of neuropathic joints. This study explored the clinicopathological and histopathological correlations between advanced OA and neuropathic joints, hypothesizing clinical similarities.

A retrospective study involving 43 patients who underwent total knee arthroplasty for advanced knee OA was conducted from 2016 to 2020. Clinical, radiological, and histopathological evaluations were performed. Advanced OA was defined as an Ahlbach grade IV or above. The functional Knee Society Score (KSS) was used to assess clinical severity, and histopathology was considered "significant" if the results were consistent with the neuropathic joint findings. The statistical analyses included univariate and binary logistic regression analyses.

The mean age was 57.63 ± 17.13 years, and most patients were females (69.77%). A total of 53.49% of the grading systems yielded histopathological findings resembling those of neuropathic joints. Univariate analysis revealed significant correlations between histopathology and the functional KSS, Ahlbach grade, and NRS score (p < 0.01). Binary logistic regression confirmed that KSS (< 40) and NRS score (< 7) were significant predictors (p < 0.001, Nagelkarke R ²  = 0.576).

Patients with advanced knee OA may exhibit characteristics resembling those of neuropathic joints, particularly individuals with a poorer functional knee. Thorough assessments are crucial for distinguishing between primary OA and neuropathic joint pathology and for carrying out more precise management strategies. This study provides valuable insights into the complex presentation of advanced knee OA and highlights the importance of using more constrained prosthesis and long stem components for potentially better outcomes.