[Scanning electron microscopy of the synovial membrane of the distal phalangeal joint and the navicular bursa in horses].

20 extremities of horses were used to investigate the synovial membrane of the distal interphalangeal joint and the navicular bursa. From each extremity five specimens were taken from the distal interphalangeal joint capsule, two further from the navicular bursa. Synovial villi were found near the articular cartilage as well as everywhere where the joint capsule did not form a tight periostal cover or was not connected with ligaments or tendons. Some lay between the articular surfaces of the phalanx media and phalanx distalis. Besides synovial villi and synovial folds "trabecular-like" cords of synovial membrane were demonstrated in the dorsal recess of the distal interphalangeal joint. These extend from one side of synovial membrane to another but they do not have a free ending. The surface of the synovial membrane and the arrangement of several synovial structures are documented.