Limb Shortening. Although limb shortening is a risk in virtually any growth plate fracture, it is particularly common in Salter-Harris type V injuries, in which the growth plate is crushed and destroyed (see Plate 9-8). Children with growth plate injuries require periodic re-examination to ascertain that normal bone growth is occurring. Radiographs taken 6 to 9 months after fracture should show an open growth plate and continued longitudinal growth. The physical examination must document that the limb lengths are remaining equal. This determination is most important because modest limb length discrepancies are best treated by stopping the growth of the uninjured limb with epiphysiodesis as soon as complete growth arrest is demonstrated in the injured limb.
Angular Deformity. Partial damage to the growth plate may produce a partial growth arrest. When a portion of the growth plate ceases to grow, an angular deformity results. This particular deformity is frequently seen in the distal femur after a Salter-Harris type II fracture in which the medial portion of the growth plate is damaged (see Plate 9-8). The medial portion of the physis stops growing while the lateral portion continues to grow, producing a varus deformity of the limb. A similar angular deformity can occur in the forearm or the leg when the growth plate of one bone is injured and fuses prematurely while the remaining bone continues to grow. For example, when a fracture of the tibia damages the entire proximal or distal growth plate, continued longitudinal growth of the fibula forces the limb into a varus position.
After some growth plate injuries, a bone bridge forms across a portion of the growth plate, arresting growth and creating a significant deformity. To prevent these complications, the bone bridge must be completely removed. Extensive preoperative planning is necessary to identify the extent of the bone bridge and is typically done with computed tomography and magnetic resonance imaging. After resection of the bone bridge, Silastic, autogenous fat, or even a physeal graft harvested from the iliac crest can be packed into the defect to prevent the bridge from re-forming. If this surgical procedure is effective in maintaining an open growth plate, longitudinal growth resumes, reducing the risk of further angular deformity. Despite the technique for bony bridge resection or what material is used for interposition, significant angular deformity is typically not corrected. However, resecting the bone bridge will likely decrease the number of osteotomies that need to be performed to fully correct a residual deformity when the child reaches skeletal maturity.
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