Objectives

To evaluate whether the concentration of C2C, CTX1 and ICTP in synovial fluid and serum of dogs diagnosed with medial coronoid disease (MCD) is associated with the severity of disease and the presence or absence of defined clinical, cytological, computer tomography and arthroscopic findings.

Methods

Nineteen dogs were recruited prospectively. Synovial fluid samples were collected from 35 elbow joints at the time of arthroscopic examination. CT images, surgical reports and synovial fluid cytology findings were reviewed for presence of predetermined features. Concentrations of C2C, CTX-1 and ICTP were correlated with clinical, pathological, CT and arthroscopic findings. Associations between serum and synovial fluid biomarkers and clinical, cytological, arthroscopic and CT features were assessed.

Results

A positive correlation was demonstrated between serum CTX1 and both serum ICTP (R_s = 0.853, P = < 0.005) and serum C2C (R_s = 0.506, P = 0.008). Synovial fluid CTX1 concentration positively correlated with cytological assessment of severity (i.e., normal, mild, moderate or severe degenerative joint disease) (R_s = 0.547, P = 0.023). Median synovial ICTP concentration was significantly greater in elbows with humeral condylar erosion (45.2 ng/mL) compared to those without (30.55 ng/mL, P = 0.025).

Clinical Significance

Concentrations of C2C, CTX1 and ICTP in synovial fluid and serum were not consistently associated with the clinical signs nor the presence of pre-defined arthroscopic and CT changes typically observed in dogs with MCD. Synovial ICTP concentration may have some potential as a biomarker for diagnosis of humeral condylar cartilage erosion. Despite this the selected biomarkers may not be of clinical use.