Evaluation of a palmar approach to the carpal flexor tendon sheath

Background

A palmar approach for centesis of the carpal flexor tendon sheath has not been reported.

Objective

To determine the feasibility and accuracy of a palmar approach to an undistended carpal flexor tendon sheath.

Study design

In vivo and experimental.

Methods

Both forelimbs of six horses were used. A 20-gauge, 8.9- or 7.62-cm spinal needle was inserted 3–4 cm proximal to the dorsal border of the accessory carpal bone in the space between the ulnaris lateralis and flexor carpi ulnaris muscles and directed sagittally and perpendicular to the long axis of the limb until the needle contacted the radius. The needle was retracted slightly, contrast medium was injected, and a laterally projected radiograph of the carpus and distal aspect of the radius was obtained and examined.

Results

The technique, when performed on 12 limbs of six horses, was 92% accurate. For one limb, the needle was inadvertently directed slightly ventrally, rather than perpendicular to the long axis of the limb, causing it to contact the radius near its physeal remnant, resulting in centesis of the antebrachiocarpal joint.

Conclusions

The palmar approach to the carpal flexor tendon sheath appears to be highly accurate.