Correlation of prostaglandin E2 concentrations in synovial fluid with ground reaction forces and clinical variables for pain or inflammation in dogs with osteoarthritis induced by transection of the cranial cruciate ligament.
OBJECTIVE
To evaluate the temporal pattern of prostaglandin (PG) E2 concentrations in synovial fluid after transection of the cranial cruciate ligament (CCL) in dogs and to correlate PGE2 concentrations with ground reaction forces and subjective clinical variables for lameness or pain.


METHODS
19 purpose-bred adult male Walker Hounds.


METHODS
Force plate measurements, subjective clinical analysis of pain or lameness, and samples of synovial fluid were obtained before (baseline) and at various time points after arthroscopic transection of the right CCL. Concentrations of PGE2 were measured in synovial fluid samples, and the PGE2 concentrations were correlated with ground reaction forces and clinical variables.


RESULTS
The PGE2 concentration increased significantly above the baseline value throughout the entire study, peaking 14 days after transection. Peak vertical force and vertical impulse significantly decreased by day 14 after transection, followed by an increase over time without returning to baseline values. All clinical variables (eg, lameness, degree of weight bearing, joint extension, cumulative pain score, effusion score, and total protein content of synovial fluid, except for WBC count in synovial fluid) increased significantly above baseline values. Significant negative correlations were detected between PGE2 concentrations and peak vertical force (r, -0.5720) and vertical impulse (r, -0.4618), and significant positive correlations were detected between PGE2 concentrations and the subjective lameness score (r, 0.5016) and effusion score (r, 0.6817).


CONCLUSIONS
Assessment of the acute inflammatory process by measurement of PGE2 concentrations in synovial fluid may be correlated with the amount of pain or lameness in dogs.
Orthopaedic Research Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Troy N
TN
Trumble
R Clark
RC
Billinghurst
C Wayne
CW
McIlwraith
D000704:Analysis of Variance; D000818:Animals; D000070598:Anterior Cruciate Ligament Injuries; D001169:Arthritis, Experimental / Q000378:metabolism / Q000503:physiopathology / Q000662:veterinary*; D001696:Biomechanical Phenomena; D015232:Dinoprostone / Q000378:metabolism*; D004283:Dog Diseases / Q000378:metabolism* / Q000503:physiopathology; D004285:Dogs; D007794:Lameness, Animal / Q000175:diagnosis*; D008297:Male; D010003:Osteoarthritis / Q000378:metabolism / Q000503:physiopathology / Q000662:veterinary*; D010147:Pain Measurement / Q000662:veterinary*; D013582:Synovial Fluid / Q000378:metabolism*; D013997:Time Factors
D015232:Dinoprostone