Ligament and Tendon Enthesis: Anatomy and Mechanics - Structural Interfaces and Attachments in Biology - page 70

Fig. 4.3 Typical load-elongation curve of the femur-MCL-tibia complex

4.3 Development, Growth, and Aging

4.3.1 Changes with Skeletal Maturity

4.3.1.1 Embryology

The development of ligaments and tendons to bone is unique and it is important to
better understand the structure-function relationships in these tissues. Between
7 and 8 weeks of embryonic life, the ligaments, tendons, and joint capsules begin
development by cellular condensations, forming in situ as a unit without migration.
The overall development of the insertion site proceeds along with that of the bone.

4.3.1.2 Skeletally Immature

Before skeletal maturation, bone growth is longitudinal and coincides with the
lengthening of the insertion site, so that a constant position relative to the growth
plate and adjacent joint can be maintained. This is why the indirect insertion is
needed. D

orlf [ 62 ] sought to explain the cause and method of migration of tendon
insertions in immature rabbits by using Tetracycline as a marker of osteogenesis at
the insertion sites. He found that insertion site migration is caused by dragging of
the insertion by the periosteum, which is itself pulled by the epiphyses as they grow
away from the diaphyses of the bone. In our studies of the rabbit MCL, we have

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