[Transverse groove of the elbow joint. A biomechanical interpretation of its origin].

The division of the trochlear notch into a dorsal and a volar part by a furrow free of cartilage covering has been previously described by several authors. This subdivision is present in about 2/3 of the adults, while it is regularly absent in children. Several earlier attempts of interpretation could be refuted by some other authors, others seem not to be sufficient to vs. The fact, that living articular cartilage swells under functional stressing induced our conception about the change of the joint congruency by this swelling. The compensation of this incongruency by the joint pressure causes an alteration of the stress pattern, hereby the deepest part of the joint becomes relatively discharged. According to the theory of the functional adaptation of the connective and supporting tissues the cartilage in the less stressed areas becomes reduced and thus the transverse notch arises, while the thickness of cartilage in the dorsal and the volar part increases.