Table 2

Prevalence of knee osteoarthritis and its related outcomes in ex-footballers compared with the general population

Prevalence, n (%)RR (95% CI)
FootballersGeneral populationCrudeModel 1Model 2Model 3
Self-reported outcomes
 Current knee pain630 (52.2)1100 (26.9)1.94 (1.80 to 2.09)1.91 (1.77 to 2.06)1.48 (1.38 to 1.63)1.50 (1.28 to 1.76)
 Physician-diagnosed knee OA341 (28.3)500 (12.2)3.53 (3.15 to 3.96)3.73 (3.33 to 4.17)2.69 (2.36 to 3.07)2.18 (1.73 to 2.77)
 Total knee replacement134 (11.1)157 (3.8)2.88 (2.31 to 3.60)3.61 (2.90 to 4.50)2.33 (1.84 to 2.95)2.10 (1.42 to 3.14)
Radiographic outcomes
 Nottingham Line Drawing Atlas (>2 osteophyte and >2 joint space narrowing)301 (64.0)173 (35.2)1.82 (1.58 to 2.08)2.21 (1.92 to 2.54)1.91 (1.65 to 2.22)1.92 (1.66 to 2.23)
 Kellgren Lawrence (grade >3)134 (28.5)69 (14.1)2.02 (1.56 to 2.63)2.46 (1.89 to 3.22)2.10 (1.58 to 2.80)2.08 (1.56 to 2.79)
 Kellgren Lawrence (grade >2)257 (54.7)154 (31.4)2.06 (1.692.53)2.46 (2.11 to 3.02)1.99 (1.60 to 2.49)1.97 (1.58 to 2.46)
 Chondrocalcinosis114 (24.3)43 (8.8)2.77 (1.99 to 3.84)3.41 (2.44 to 4.77)2.63 (1.84 to 3.75)2.57 (1.80 to 3.66)
  • *RR adjusted for football status, age, BMI.

  • †RR adjusted for football status, age, BMI and injury.

  • ‡RR adjusted for football status, age, BMI, nodal OA, injury, constitutional alignment, high-risk occupation, 2D:4D ratio, nodal OA, comorbidities.

  • BMI, body mass index; OA, osteoarthritis; RR, relative risk.