Growth arrest occurs when there is damage to a growth plate resulting from a fracture. There are many causes that may cause growth arrest including:
- Vascular Injury
- Metabolic Disorders
- Iatrogenic Diseases
The growth plate (or physis) is located at the ends of long bones (e.g. the femur, the tibia) in children and adolescents. Each of these bones has two growth plates at each end of the bone. During childhood the growth plates are “open” in that there is a gap where new bone is formed. This is where the growing occurs during childhood. At some point during adolescence the growth plates close and the gap disappears. At this point, the bones will no longer increase in length. When there is damage to the growth plate, this can cause the growth plate (or sections of it) to close prematurely, forming a bony bridge known as a “bar.”
There are different categorizations of growth arrest, depending on the degree and location of arrest:
- Partial vs. Complete
- Peripheral vs. Central vs. Elongated
In a complete growth arrest, a large enough section of the growth plate has closed and the bone will no longer grow. A limb length discrepancy will then result, the magnitude of which depends on the age of the arrest.
In a partial growth arrest, a smaller section of the growth plate has closed and a deformity may result, the specific nature of the deformity depending on the location of the arrest. In a peripheral arrest, asymmetric (uneven) growth of the growth plate results in an angular deformity. In a central arrest, a limb length discrepancy may result since there is tethering of the growth plate; this tethering may also alter the shape of the joint, especially in the knee.
Limb length discrepancies are a common problem following growth arrest and occur when there is arrest in one limb and not in the opposite side. The affected limb will cease to grow, resulting in a discrepancy. In some cases, bilateral involvement may occur (e.g. meningococcemia), in which short stature occurs. Growth arrest can also result in a progressive deformity, extra-articular (outside the joint) or intra-articular (inside the joint).
Treatment for growth arrest involves correcting the resultant deformities and addressing the limb length discrepancy or short stature. A variety of techniques have been proposed to treat the many forms of growth arrest. These will be described in the next section