The physiopathology of osteoarthritis: Paleopathological implications of non-articular lesions from a modern surgical sample.

OBJECTIVES: This research focused on osteoarthritis (OA) lesions on modern patients to 1) identify consistently observed lesions not included within current paleopathological measures of OA, 2) assess the correspondence of bone and cartilage lesions with clinical OA diagnostic criteria, and 3) discuss the correspondence of bone lesions with sources of pain reported in clinical literature. MATERIALS: Tibial plateaus from 62 patients undergoing total knee replacement surgery due to OA were examined. METHODS: Plateaus were scored for several non-standard OA criteria, including non-articular and X-ray visible lesions and pre-maceration cartilage lesions, as well as articular surface criteria standard in paleopathology. RESULTS: Proliferative bone in the intercondylar region was present in 95 % of specimens, while areas of dense trabecular bone and lytic defects, both on the inferior side of the plateaus, were present in 98 % and 83 %, respectively. CONCLUSIONS: The inferior lytic defects may be physical evidence of bone marrow lesions (BML), a clinical OA indicator visible via MRI. Previous research has linked BML to pain, inflammation, and ligament pathology. The latter conditions have also been associated with intercondylar enthesophytes and third intercondylar tubercle of Parsons (TITP), both of which were observed in the intercondylar regions. SIGNIFICANCE: Several non-articular lesions not currently included in paleopathological measures of OA were consistently observed. SUGGESTIONS FOR FUTURE RESEARCH: A similar analysis of a control sample of non-OA tibial plateaus would better contextualize these results. LIMITATIONS: The sample's high average age (65.8 years) and severe OA stage may hamper generalizability to archaeological collections.