Chapter 133

The anatomy of the pediatric musculoskeletal system is unique and reflects the active growth and development that occurs during childhood. Fracture classification, treatment approach, and types of complications are directly related to this unique anatomy. Perhaps the most helpful way to divide pediatric musculoskeletal injuries is those occurring before and after fusion of the physes (growth plates). In general, both injury patterns and treatment approaches in children in whom closure of the physes has already occurred is similar to those of the adult. Therefore, the major focus of this chapter is directed at injuries occurring in the prepubescent child. In addition, diseases specific to children that cause nontraumatic musculoskeletal complaints are also covered.

The long bones of children consist of discrete anatomic areas. The physis is an area of growth cartilage and may occur at one (e.g., the phalanges) or both (e.g., the tibia and the femur) ends of a long bone. The area of bone between a physis and the adjacent joint is termed the epiphysis. An apophysis is a type of growth plate that occurs at the end of a bone when there are no bones on the other side (e.g., calcaneous) and often serves as a point for muscle or ligament attachment. The midshaft of a long bone is referred to as the diaphysis. The metaphysis of a long bone represents the area between the diaphysis and the physis (Figure 133-1; see Chapter 264, Initial Evaluation and Management of Orthopedic Injuries).

###### Figure 133-1.

The anatomy of the pediatric long bone as demonstrated by the femur. Longitudinal growth occurs at the physes (growth plates) located at either end. Bony prominences that serve as sites of muscular or ligamentous attachment are known as apophyses (e.g., greater and lesser trochanteric apophysis).

The long bones of children are less dense and more porous than the long bones of adults. Pediatric long bones respond to mechanical stress by bowing and buckling, rather than fracturing through and through, as in adults. The periosteum of the diaphysis and the metaphysis is thick in children and is continuous from the metaphysis to the epiphysis, surrounding and protecting the mechanically weaker physis. The weakness of the physis is, in part, related to the reduced oxygen tension found in the hypertrophic zone of the physis. This hypertrophic zone is the location of frequent fractures within the physis. The physis is also sensitive to alterations in the blood supply, and physeal injuries can result in growth disturbance.

The growth of the musculoskeletal system and its response to injury are also influenced by the growth of muscle and connective tissue. The ligaments of children are stronger and more compliant than in adults, and ligaments tolerate mechanical forces better than the weaker physis. Therefore, apophyseal detachments or epiphyseal fractures are much more common than ligamentous injuries during ...

Sign in to your MyAccess Account while you are actively authenticated on this website via your institution (you will be able to tell by looking in the top right corner of any page – if you see your institution’s name, you are authenticated). You will then be able to access your institute’s content/subscription for 90 days from any location, after which you must repeat this process for continued access.

Ok

## Subscription Options

### AccessMedicine Full Site: One-Year Subscription

Connect to the full suite of AccessMedicine content and resources including more than 250 examination and procedural videos, patient safety modules, an extensive drug database, Q&A, Case Files, and more.