Summary
The genual joint in horses is complex, making synovial fluid aspiration and injection of the femoropatellar joint difficult. Horses commonly have signs of resentment to needle penetration at this site. We compared the safety and efficacy of a new technique, using a lateral approach to the femoropatellar joint, with that of the standard cranial approach in 12 horses. A significantly greater amount of fluid was obtained with the lateral approach (2.0 ± 0.5 ml, mean ± sem) than with the cranial approach (0.9 ± 0.2 ml). Significant differences were not observed in color, nucleated cell count, rbc count, or total protein of the fluid. Mean articular cartilage injury score was significantly lower with the lateral approach (0.3 ± 0.3), compared with that from the cranial approach (1.3 ± 0.4). Only 8% of the joints (1/12) in which the lateral approach was used were injured, compared with 67% (8/12) in the cranial approach. The lateral approach yielded more fluid and was less likely to result in injury to the articular surface than was the cranial approach.
