An anatomic study on the attachment of the joint capsule to the tibia in the lateral side of the knee.

Abstract

The purpose of the current study was to examine the width, area, and histological characteristics of the capsular attachment to the tibia in the lateral side of the knee. A total of 27 knees were used in this study. The joint capsule of the knee was peeled away from the tibia and the width of the capsular attachment to the tibia was measured by two independent observers using a caliper. Interclass correlation coefficients for each value were calculated to evaluate the validity of the measurement. The capsular attachment to the tibia of the seven knees was histologically analyzed using Masson's trichrome staining. At the posterior border of Gerdy's tubercle, the capsular attachment was wide; the average width was 8.6mm (SD 3.0). Toward the posterolateral aspect of the knee, the capsular attachment gradually tapered. Finally, the capsular attachment was linear at the apex of the head of the fibula. Histological analysis at the posterior border of Gerdy's tubercle revealed developed uncalcified fibrocartilage on the capsular attachment. In contrast, at the apex of the head of the fibula, the joint capsule was adhered to the capsule of the proximal tibiofibular joint. Fibrous connective tissue was directly attached to the calcified fibrocartilage. The attachment width of the knee joint capsule at the lateral side varied according to location. We consider that this finding on the capsular attachment will facilitate an understanding of the pathology or mechanism of diseases on the lateral side of the knee joint.