Synovial fluid parameters following acute articular fracture in the horse.

The research investigates how acute articular fractures in horses can affect parameters in synovial fluid, yielding results which can aid in decision-making when it comes to acutely lame horses.

Research Methods

• The researchers undertook a retrospective case study, where they examined synovial fluid samples from 54 horses over a period of 11 years. They chose samples from horses that had undergone lag screw fixation or arthroscopic fragment removal of fractures within the joint, which occurred within 48 hours.
• If a horse had wounds near the joint or if treatment was delayed for more than 48 hours, it was not included in the study.
• The total nucleated cell count (TNCC) in the synovial fluid was then compared within two different groups, which were separated based on the time since the occurrence of the fracture – less than 8 hours and more than 8 hours.

Findings

• Out of all the horses included in the study, 55 synovial samples were obtained. Most of these were from metacarpo/tarsophalangeal joints (49 samples), while the others were taken from intercarpal joints (6 samples).
• The median TNCC for all samples was 20.6 x 10/L, although this ranged from 0.1-76.1 x 10/L. The TNCC was higher than 30 x 10/L in 17 cases, which is roughly 30.9% of all the samples.
• The researchers found that the higher TNCCs were generally recorded sooner after the fracture occurred (less than 8 hours).
• For total protein concentration (TP), the median level was 40 g/L, though this varied between 4-76 g/L. The median neutrophil percentage was 83.0%, with a range from 0% to 93%.
• The researchers also found that there was no significant difference observed in synovial samples taken from different joints or from horses with different fracture configurations.
• Among cases where the appearance of the fluid could be grossly determined (35 cases), hemarthrosis or bleeding into the joint space, was presented in 94.6% of the cases.

Conclusion

• The findings of the research suggest that acute intra-articular fractures in horses can elevate synovial fluid parameters above values that would normally indicate septic arthritis, a painful infection in a joint.
• However, the researchers also note that the study had its limitations, including a small sample size and the absence of multiple samples to examine changes over time.
• Despite these limitations, the study provides crucial evidence indicating that there might be overlaps in synovial fluid parameters in cases of acute intra-articular fractures and septic arthritis. This suggests the need for careful consideration when diagnosing horses based on these parameters.