Table 2

Prevalence of medial and lateral PF cartilage damage in BOKS, FOA and MOST studies

Definition of PF cartilage damage
Patellar (cartilage morphology score)Either patellar or trochlear (cartilage morphology score)
≥2≥3≥4≥5≥2≥3≥4≥5
BOKSMedial PF damage % (n/N knees)75.0** (168/224)68.8* (154/224)48.2 (108/224)26.8 (60/224)84.4** (189/224)79.0* (177/224)55.8 (125/224)30.4 (68/224)
Lateral PF damage % (n/N knees)61.6 (138/224)58.0 (130/224)45.5 (102/224)24.1 (54/224)73.7 (165/224)68.8 (154/224)54.5 (122/224)28.6 (64/224)
FOA (all knees)Medial PF damage % (n/N knees)55.6** (644/1159)38.3** (444/1159)15.6* (181/1159)12.0** (139/1159)60.1** (693/1153)43.5** (501/1153)18.3* (211/1153)14.7* (170/1153)
Lateral PF damage % (n/N knees)38.3 (444/1159)30.7 (356/1159)12.3 (143/1159)8.0 (93/1159)41.5 (479/1153)33.6 (387/1153)15.2 (175/1153)11.1 (128/1153)
FOA (knees with measured alignment)Medial PF damage % (n/N knees)64.7** (277/428)50.0* (214/428)23.4* (100/428)17.8** (76/428)70.0** (298/426)57.5** (245/426)27.0 (115/426)21.1 (90/426)
Lateral PF damage % (n/N knees)50.93 (218/428)43.22 (185/428)16.59 (71/428)10.98 (47/428)55.4 (236/426)47.7 (203/426)21.6 (92/426)16.4 (70/426)
MOSTMedial PF damage % (n/N knees)62.7** (1017/1621)51.6** (837/1621)20.3 (329/1621)18.6 (302/1621)69.2** (1116/1613)56.1** (905/1613)21.6 (349/1613)19.8 (319/1613)
Lateral PF damage % (n/N knees)45.3 (735/1621)38.4 (623/1621)19.7 (320/1621)16.6 (269/1621)51.1 (824/1613)43.2 (696/1613)23.6 (380/1613)20.5 (331/1613)
  • Crude comparison (χ2) of medial to lateral PF cartilage damage prevalence indicates statistically significant difference: *p<0.05; **p<0.01.

  • BOKS, Boston Osteoarthritis of the Knee Study; FOA, Framingham Osteoarthritis Study; MOST, Multicenter Osteoarthritis Study; PF, patellofemoral.