The technique for accurate biplane osteotomy at the level of the lesser trochanter for the treatment of slipped capital femoral epiphysis by making reasonably accurate roentgenographic measurements is described and illustrated.

Correction of one deformity by producing a reverse deformity at another level may not be esthetically appealing but an osteotomy through the lesser trochanter for slipped capital femoral epiphysis has the following advantages:

1. It does not seem to cause avascular necrosis of the head of the femur;

2. It does not open or directly assault the hip joint;

3. It seems to stimulate early closure of the slipped epiphyseal plate;

4. It does not prevent further corrective surgery at a second stage if need be;

5. If performed accurately it can be expected to restore hip function in almost every patient.

Fifty-five patients have been treated by this method and avascular necrosis has not occurred. The results in twenty-six patients followed five years or more are reported in detail.

Patients who have the complication of joint-space narrowing (not avascular necrosis) with joint stiffness should be given adequate time and rest, probably three years or more, to allow regeneration of the joint space to occur before consideration is given to reconstructive procedures. A possible mechanism for this narrowing and for the later restoration of the space is discussed.