Knee Arthritis Risk Factors and Prevention

Primary Risk Factors

Previous knee trauma significantly increases the risk of developing osteoarthritis, with various single and multistructure knee injuries increasing the odds of symptomatic OA with moderate-certainty evidence, according to the British Journal of Sports Medicine 1, 2
Specific injuries with increased OA risk include cruciate ligament injuries, collateral ligament injuries, meniscal injuries, chondral injuries, patellar/tibiofemoral dislocations, knee fractures, and multistructure injuries, as reported by the British Journal of Sports Medicine 2, 3

Post-traumatic OA accounts for approximately 12% of all OA cases globally, affecting about 36 million people, with very-low certainty evidence suggesting increased odds of structural OA related to ACL reconstruction with cartilage injury, partial meniscectomy, or total medial meniscectomy, as found by the British Journal of Sports Medicine 2, 3

Prevention efforts should focus on implementing evidence-based injury prevention programs, and addressing modifiable risk factors such as minimizing unhealthy adiposity and strengthening quadriceps muscles, as recommended by the British Journal of Sports Medicine 4

The American Academy of Orthopaedic Surgeons suggests that age is a significant risk factor, with nearly 50% of people developing symptomatic knee OA by age 85 5
Genetics play a significant role, with estimates from twin studies showing heritability of 0.39-0.65, according to the American College of Rheumatology 6, 7
Hormonal factors may contribute to the higher prevalence of knee OA in women, as noted by the American College of Rheumatology 6

Previous trauma, such as joint injury, significantly increases the risk of subsequent OA development, as reported by the American Academy of Orthopaedic Surgeons 6, 8
Joint alignment, particularly abnormal mechanical loading due to malalignment, contributes to cartilage degeneration, according to the American College of Rheumatology 6

Articular cartilage degeneration is the primary pathological feature of knee OA, characterized by focal loss of cartilage, as described by the American College of Rheumatology 6, 9
Bone changes, including marginal and central new bone formation (osteophytes), are a key aspect of knee OA, as noted by the American College of Rheumatology 6

Moderate‑certainty evidence shows that any previous knee injury markedly raises the likelihood of subsequent patellar chondral damage, and that chondral lesions themselves are independent risk factors for developing symptomatic knee osteoarthritis. 10
History of anterior cruciate ligament (ACL) reconstruction, meniscal tears (partial or total), or patellar dislocation creates a cascade that predisposes the joint to cartilage degeneration and future chondral injury. 11

Women who sustain an ACL reconstruction together with a cartilage lesion have a 2.3‑fold higher odds of structural osteoarthritis compared with isolated ACL injury.
Partial meniscectomy combined with cartilage damage increases osteoarthritis odds by 1.9‑fold, while total medial meniscectomy raises the odds to 3.1‑fold. (All odds ratios derived from the same cohort.) 10

A focal patellar chondral delamination measuring approximately 3 mm × 10 mm with an intact basal layer is interpreted as the result of acute shear forces (e.g., rapid deceleration or cutting) rather than chronic degenerative change. 12

Presence of a patellar chondral injury significantly elevates the athlete’s risk of developing post‑traumatic knee osteoarthritis, warranting ongoing surveillance and early intervention. 11