Objective—To determine whether serum concentrations
of biomarkers of skeletal metabolism can,
in conjunction with radiographic evaluation, indicate
severity of osteochondrosis in developing
Animals—43 Dutch Warmblood foals with varying
severity of osteochondrosis.
Procedure—24 foals were monitored for 5 months
and 19 foals were monitored for 11 months. Monthly
radiographs of femoropatellar-femorotibial and tibiotarsal
joints were graded for osteochondral abnormalities.
Serial blood samples were assayed for 8 cartilage
and bone biomarkers. At the end of the monitoring
period, foals were examined for macroscopic
Results—Temporal relationships were evident
between certain serum biomarkers and osteochondrosis
severity in foals during their first year.
Biomarkers of collagen degradation (collagenasegenerated
neoepitopes of type-II collagen fragments,
type-I and -II collagen fragments [COL2-3/4Cshort],
and cross-linked telopeptide fragments
of type-I collagen) and bone mineralization (osteocalcin)
were positive indicators of osteochondrosis
severity at 5 months of age. In foals with lesions at
11 months of age, osteochondrosis severity correlated
negatively with COL2-3/4Cshort and osteocalcin
and positively with C-propeptide of type-II procollagen
(CPII), a collagen synthesis marker.
Radiographic grading of osteochondrosis lesions
significantly correlated with macroscopic osteochondrosis
severity score at both ages and was
strongest when combined with osteocalcin at 5
months and CPII at 11 months.
Conclusions and Clinical Relevance—The ability of
serum biomarkers to indicate osteochondrosis severity
appears to depend on stage of disease and is
strengthened with radiography. In older foals with
more permanent lesions, osteochondrosis severity is
significantly related to biomarker concentrations of
decreased bone formation and increased cartilage synthesis.
(Am J Vet Res 2004;65:143–150)