Ultrasound-Guided Proximolateral Approach for Digital Flexor Tendon Sheath Injection in the Horse: A Cadaver Study

Caitlyn R Horne,Lauren V Schnabel,William R Redding,Hongyu Ru

doi:10.1055/s-0039-1696962

Abstract

Abstract Objectives The aim of this study was to define a reliable ultrasound-guided proximolateral approach (PLA) for injection of the digital flexor tendon sheath (DFTS) in horses that would be as accurate as the landmark-guided basilar sesamoidean approach (BSA). Study Design Forty cadaveric limbs with no palpable effusion or DFTS abnormalities were randomly and evenly distributed between one senior (WRR) and one resident clinician (CRH) and between ultrasound-guided PLA and landmark-guided BSA groups. Limbs were injected with contrast, radiographed, and dissected. For each injection, the following was recorded: clinician, order of injection, number of attempts, if contrast was present within the DFTS, and if a structure other than the DFTS was penetrated. Results The ultrasound-guided PLA resulted in a greater number of successful injections into the DFTS than the landmark-guided BSA (19/20 vs. 16/20, respectively) with significantly fewer attempts (p = 0.03). The ultrasound-guided PLA also resulted in significantly less penetration of the surrounding soft tissue structures compared with the landmark-guided BSA (p = 0.02). Neither clinician experience nor injection number within the series was determined to have an effect on injection outcome. Conclusions The ultrasound-guided PLA to the DFTS is accurate and technically easy to perform. This approach should be considered for synoviocentesis of the DFTS, particularly in cases in which effusion is not present to reduce soft tissue trauma.

Highlights

Injection of the digital flexor tendon sheath (DFTS) is becoming a more commonly utilized technique in the diagnosis and management of distal limb injuries in the horse
The limb injected was found to be significantly more successful with hindlimbs having a greater success rate overall (p 1⁄4 0.05). When these input factors were entered into a logistic regression model, none of the factors were determined to have a significant effect on successful DFTS injection
The results of this study revealed that in our hands the use of the ultrasound-guided e42 Ultrasound-Guided Proximolateral Approach for DFTS Injection Horne et al Table 2 Association between input factors and successful digital flexor tendon sheath injection

Summary

Introduction

Injection of the digital flexor tendon sheath (DFTS) is becoming a more commonly utilized technique in the diagnosis and management of distal limb injuries in the horse. The use of intrathecal contrast material with either radiography or computed tomography has recently been described to diagnose deep digital flexor tendon (DDFT) and manica flexoria (MF) tears.. A variety of injuries to structures associated within the DFTS some of which may manifest few localizing signs. To determine the clinical relevance of some of these injuries requires the placement of local anaesthetic into the DFTS. In cases without significant effusion within the DFTS, accurate needle placement into the synovial space can be difficult.. Treatment of these injuries, such as with regenerative therapies, often requires accurate placement of the appropriate elected treatment into the synovial space In cases without significant effusion within the DFTS, accurate needle placement into the synovial space can be difficult. In addition, treatment of these injuries, such as with regenerative therapies, often requires accurate placement of the appropriate elected treatment into the synovial space

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