The advent of improved clarity of intraoperative radiographic image intensification has facilitated the use of a closed technique, percutaneous epiphysiodesis. A very small incision is made over a Steinmann pin placed medially to laterally in the plane of the growth plate. A cannulated reamer is placed over the pin and used to begin removal of the growth plate, which is completed by power drilling or curettage or both. Viscous lidocaine and a radiographic contrast medium are injected into the defect, and the limb is rotated under the image intensifier to determine the adequacy of the procedure. Morbidity is quite low, and the scar is much more acceptable to patients than that of open epiphysiodesis.
Epiphyseal stapling retards, but does not stop, growth (see Plate 4-35). Unlike epiphysiodesis, the procedure must be performed on a younger patient to achieve the same growth retardation, but it should not be done before the child reaches the skeletal age of 8 years. If growth is to be resumed, the staples must be removed before growth of the epiphysis has ceased.
After the staples are removed, a rebound phenomenon, or initial growth spurt, may occur, followed by continuation of growth at the normal rate. A previously stapled epiphysis usually closes a few months prematurely, which tends to compensate for the spurt in growth. Although there are many technical problems associated with the stapling procedure, the theoretical advantages of stapling—such as the ability to control angular and length deformities—make it a worthwhile consideration.
Resection of bone from the longer limb may be performed to correct leg-length discrepancy in skeletally mature patients and may also simultaneously correct any associated angular or rotational deformities. The risk of excessive shortening is muscle weakness, which can be manifested in the femur as a knee extension lag due to decreased quadriceps strength.
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