34.1 Introduction

Femoral rotational osteotomy is a surgical procedure performed on pediatric patients with excessive femoral anteversion. In growing children, femoral anteversion typically decreases from 30 to 50 degrees, at birth, and reaches on average 15 degrees, by the time of skeletal maturity. When this decrease in femoral anteversion does not occur, patients may have anterior hip pain as well as an in-toeing gait. Surgery in this patient population is limited to those with significant hip pain and an in-toed gait that causes functional deficits and a decreased quality of life. Excessive femoral anteversion can also be seen in combination with external tibial torsion, also known as “malignant malalignment.” These two deforming factors can lead to significant patellofemoral pain and patellar instability. In this situation, a corrective osteotomy may also be indicated. ¹ Finally, cerebral palsy is often associated with increased femoral anteversion due to developmental delays and muscle contractures. This again will lead to an in-toeing gait, but surgical indications in this patient population is again limited except for patients with gross motor functional classification system levels IV or V where, in combination with coxa valga, increased femoral anteversion puts these nonambulatory patients at the risk of subluxation or dislocation of the hip joint.

34.2 Preop

Preoperative X-rays and CT scans are crucial in determining the amount of correction that is needed to improve hip kinematics. Anteroposterior (AP) pelvis X-rays can determine any signs of coxa valga and possible hip subluxation that would require pelvic osteomies. A CT scan for rotational alignment should be ordered to evaluate the degree of correction required. Axial images of the femur, with the leg internally rotated 15 degrees, should be used to create a line down the longitudinal axis of the femoral neck. This line should then be measured against a line drawn between the lateral posterior femoral condyles. These lines, when measured against each other, form the anteversion angle and allow the surgeon to determine the degree of correction required. All patients should also undergo dynamic gait assessment for correction required. Fixation of the osteotomy can be achieved by using either a blade plate or an intramedullary nail; the choice is based on the surgeon preference (▶Fig. 34.1 and ▶Fig. 34.2).

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  Surgical table. Radiolucent table flat table

  
  
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  Patient positioning. Supine with a, “bump,” placed under the patient’s sacrum or prone, where care should be taken to pad the patients soft tissue, including chest, iliac crests, abdomen and genitalia. Image intensifier should be placed on opposite side of the patient with the monitor placed at the foot of the bed.

  
  
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  Patient exam. Examination of patients’ dorsalis pedis and posterior tibial pulses as well as sensory and motor examination of the lower extremity should be performed.

34.3 Approach

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  It is the same in both the supine and prone positions.

  
  
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  A 3–7 cm line is drawn on the patient beginning at the proximal end of the vastus ridge and extends distally in line with the femur, to mark out the incision.

  
  
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  Sharp incision through skin is made first. Then, the electrocautery is used for deeper dissection to control hemostasis.

  
  
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  Dissection continues until the tensor fascia lata is identified. Self-retaining retractors are used to hold skin flaps and improve the visualization of surgical field.

  
  
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  The tensor fascia lata (TFL) is split in line with the incision.

  
  
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  This exposes the vastus lateralis, which may be better visualized with removal of the trochanteric bursa.

  
  
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  Elevate the vastus lateralis transversely off the vastus ridge and extend in an “L” shape to improve visualization and exposure of the femur.

  
  
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  A generous sub-periosteal dissection is performed at the level of the osteotomy site to allow for rotational correction. The resection should be circumfrential and it is imperative to remove all attachments to the linea aspera along the femoral shaft to maintain the alignment postoperativly. This tissue can act as a tether leading to translation in the fragments.