[Distribution and three-dimensional reconstruction of lymphatic vessels of the elbow joint capsule of rabbits].

Lymphatic vessels are believed to be distributed in the the depth of synovial membrane, but the details of this distribution remain to be fully elucidated. The synovial membrane is classified in part on the basis of histological characteristics, even in the same joint capsule, into three fundamental types: adipose type, areolar type, and fibrous type. In addition, the adipose and areolar types are involved in the absorption of synovial fluid. In this study, the distribution of lymphatic vessels was investigated with special reference to histological structure of the synovial membrane. The materials were prepared from 11 elbow joint capsules of male 8 rabbits weighting 2-3 kg. Five specimens were stained with silver nitrate, and the remainder were stained with trichrome. All of the materials were serially sectioned and observed by light microscopy. Three-dimensional reconstructions of lymphatic vessels were performed using Cosmozone 2SA software (Nikon Co.) with a PC-9800 series microcomputer (NEC Co.) When the joint capsule is divided into synovial and fibrous layers in accordance with the Nomina Histologica Japonica, the fibrous layer is frequently connected with the epimysium of neighboring muscles. The synovial and fibrous layers are occasionally continuous with each other, without a distinct boundary. The number of lymphatic vessels in the synovial layer is small, and they originate in the vicinity of the border of the fibrous layer and pass over into the lymphatic vessels of the fibrous layer. Many lymphatic vessels were found in the fibrous layer, the majority of which come from the epimysium or perimysium close to the outer surface of the fibrous layer.(ABSTRACT TRUNCATED AT 250 WORDS)