Table 1.

Frequencies of lesions identified in 1671 horses in this study and comparisons with published data

Lesion site	n (%)	Percentage range from other studies of TBs	Percentage range from studies of non‐TBs	References: TB (non‐TB)
Any osteochondrosis	389 (23.3%)	20.5%	16.6%	15 (32)
Any stifle osteochondrosis	166 (9.9%)	6.2–10.2%	11.5–16.6%	20,26,27 (31,32)
Medial femoral condyle cyst	63 (3.8%)	0–5.6%		20,26,27
Bilateral medial femoral condyle cyst	13 (0.8%)
Lateral trochlear ridge of femur	104 (6.2%)	4.0–5.7%		26,27
Bilateral lateral trochlear ridge	44 (2.6%)
Any tarsal osteochondrosis	102 (6.1%)	6.5–10.5%	9.2–16.0%	20,26,27 (32,33)
Distal intermediate ridge of tibia	60 (3.6%)	3.0–4.4%		26,27
Bilateral distal intermediate ridge of tibia	9 (0.5%)
Lateral trochlear ridge of talus	39 (2.3%)	1.4–4.0%		20,26
Bilateral lateral trochlear ridge of talus	8 (0.5%)
Medial malleolus of distal tibia	3 (0.2%)
Both lateral trochlear ridge and distal intermediate ridge of tibia	8 (0.5%)
Any metacarpo/tarsophalangeal joint osteochondrosis	134 (8.0%)	14.6–15.4%	11.8–23.5%	26,27 (33,34)
Any distal third metacarpal/metatarsal cyst	16 (1.0%)	2.0–6.0%		20,26,27
Distal third metacarpal cyst	10 (0.6%)
Distal third metatarsal cyst	6 (0.4%)
Any dorso‐proximal P1 (DP‐P1) osteochondral fragment	62 (3.7%)	3.0–4.9%		20,26,27
Forelimb DP‐P1 fragment	24 (1.4%)
Hindlimb DP‐P1 fragment	38 (2.3%)
Bilateral forelimb DP‐P1 fragment	3 (0.2%)
Bilateral hindlimb DP‐P1 fragment	5 (0.3%)
Any P1 cyst	14 (0.8%)
Forelimb P1 cyst	5 (0.3%)
Hindlimb P1 cyst	11 (0.7%)
Bilateral hindlimb P1 cyst	0
Any distal third metacarpal/tarsal proximal sagittal ridge fragment	37 (2.2%)
Third metacarpal proximal sagittal ridge fragment	22 (1.3%)
Bilateral third metacarpal proximal sagittal ridge fragment	7 (0.4%)
Third metatarsal proximal sagittal ridge lesion	23 (1.4%)
Total number of osteochondrosis sites	505 (30.2%)

TB, Thoroughbred; non‐TB, breed other than Thoroughbred.