The correlation between the dose and distribution of intratendinous fluid injections in the flexor tendons/ligaments of the horse.

The research article discusses the impact of different doses of fluid injections into the tendons of horses’ legs, with the aim of understanding the optimal level to achieve an effective distribution without causing excessive fluid accumulation. The paper recommends that injections should be guided by ultrasound and that the routinely suggested dose in veterinary literature may be too high.

Introduction and Objectives

• The paper begins by outlining the intention to investigate the relationship between the amount (dose) of intratendinous fluid injections and their distribution within the flexor tendons and ligaments of the horse’s lower leg.
• The objective of the study was to understand how to achieve the best spread of the injected fluid within the tendon, while avoiding excessive fluid build-up, which can have negative effects.

Methodology

• The research was conducted in vitro, meaning it was carried out on removed horse tissue in a controlled environment.
• Various doses of fluid were injected into the tendon tissue, ranging from 0.1 ml to 2 ml, and the resulting spread of the fluid was observed and compared.

Findings

• The researchers found that a smaller dose (0.1-0.2 ml) resulted in a localised fluid depot (storage area) with minimal spreading outside the tendon (abaxial spreading).
• When the dose was increased to 0.3-0.5 ml, the fluid spread (proximodistal expansion) still remained largely contained within the tendon, but was significantly greater.
• However, when the dose was further increased to between 0.5 and 2 ml, there was a corresponding extensive ‘abaxial spreading’ and a pool of fluid accumulated around the tendon (peritendinous accumulation).

Conclusion and Recommendations

• The study’s observations suggest that the dose typically recommended in existing veterinary literature (2 ml) may be excessive.
• If a small lesion is present, a 0.1-0.2 ml intratendinous injection should be capable of achieving the desired distribution.
• For larger lesions, a slightly higher dose (0.3-0.5 ml) may be sufficient. However, if a large section of the tendon is injured, the injection should be divided into several smaller doses, applied roughly 5 cm apart.
• Importantly, the researchers recommend using ultrasound as a guiding tool during the injection process as it allows precise placement of the drug into the lesion.