Tenoscopic anatomy of the equine carpal flexor synovial sheath.

This research explores the anatomy of the carpal sheath of the flexor tendons in equines (horses) using a lateral tenoscopic approach. The approach was found to be effective in observing all structures within the sheath, and has potential application in various diagnostic procedures.

Methods

• This study employed tenoscopic observation and dissection on 12 equine cadaveric forelimbs.
• The limbs were positioned with the lateral side upwards and the carpus slightly flexed.
• A portal for the arthroscope was made approximately 3 cm proximal to the distal radial physis and 2.5 cm caudal to the radius, between the tendons of the ulnaris lateralis and lateral digital extensor muscles, after the distension of the carpal sheath.

Results

• It was found that a lateral tenoscopic approach was sufficient for identifying all structures within the carpal sheath.
• From proximal to distal, the observed structures included the radial head of the deep digital flexor muscle, the accessory ligament of the tendon of the superficial digital flexor muscle, distal radial physis, tendons of the superficial and deep digital flexor muscles, accessory carpal bone, antebrachiocarpal and middle carpal joints, and vincula of the tendon of the deep digital flexor muscle.

Conclusions

• The lateral tenoscopic approach provides an easy and repeatable entry into the carpal sheath, permitting a comprehensive observation of all structures within the sheath with the exception of the medial borders of the tendons of the deep and superficial digital flexor muscles.
• The potential applications of a lateral tenoscopic approach to the carpal sheath encompass diagnostic procedures, lavage and synovial resection for septic tenosynovitis, desmotomy of the accessory ligament of the tendon of the superficial digital flexor muscle for flexural deformity or tendinitis, and removal of osteochondromas from the distal radial metaphysis.