Tendons are surrounded by a lubricating fluid filled sac as they go over joints. This is called the tendon sheath. In other areas tendons are cushioned by a sac between a bone and skin called a bursa. Both these areas can get inflamed or infected and their distension may simply reflect underlying disease in the tendon itself. The ability to look into these areas with the same equipment that we use to look into a joint is called tenoscopy.
The areas that we routinely examine include the carpal sheath (behind the knee), the digital sheath (behind the fetlock-pastern- windpuff area) and the tarsal sheath (behind the hock – thoroughpin area). Extensor tendon sheaths commonly get infected at the front of the knee or hock and arthroscopic exam, flushing and debridement (surgical trimming of dead or devitalized tissue) has been very successful at saving many horses.
Tenoscopic ligament transections (same technique as for carpal tunnel in people) are useful since examination and debridement of proliferative synovitis can be done simultaneously.
For prevention and assistance in healing of superficial flexor tendonitis (bowed tendons) we do a tenoscopic proximal check desmotomy. This is done through the carpal sheath above the back of the knee and is much less invasive than the old open technique.
Tenoscopy is very useful to examine and treat various bursae including the biceps bursa (shoulder) and the Navicular bursa.