Review Question - QID 3436

The clinical presentation is consistent with severe bilateral genu valgum in a skeletally immature patient. Temporary hemiepiphysiodesis across the bilateral medial distal femoral growth plates is the most appropriate treatment.

Temporary hemiepiphysiodesis, or temporary physeal tethering using staples or tension plates, can be utilized to redirect physeal growth depending on the amount of growth calculated to remain for the child. Surgical correction is warranted if a mechanical axis line drawn from the center of the head of the femur to the center of the ankle falls in at least the outer 25% of the tibial plateau in children older than 10 years.

Wiemann et al. present a Level 4 review of 63 patients that underwent either physeal stapling or tension "8-plate" hemiepiphysiodesis. They found that the tension "8-plate"(as shown in Illustration A) is as effective as staple hemiepiphysiodesis for correction of angular deformity in terms of the rate of correction and associated complications.

Stevens presents Level 4 evidence of 34 patients that underwent nonlocking extraperiosteal "8-plate" tethering. He observed that the rate of correction was approximately 30% more rapid than noted with stapling, and that only 4 patients needed revision alignment surgery for rebound deformity.

Schroerlucke et al. report a Level 4 study of 31 patients that underwent "8-plate" tethering. They found that implant failure occurred in 8 (26%) of the proximal tibia constructs. All of these failures happened in patients with Blount's disease and involved breakage of the tibial metaphyseal screw.

Figure A displays a radiograph of bilateral genu valgum (anatomic LDFA= 80 degrees)in a skeletally immature individual. Illustration A is an example of a lateral tension band plate or "8 plate". Illustration B demonstrates the complication of screw breakage during hemiepiphysiodesis. Illustration C demonstrates a postoperative extremity alignment radiograph showing medial tension band plate tethering and correction of genu valgum.

Incorrect Answers:
Answer 1: Bracing plays no role in the treatment of severe bilateral genu valgum.
Answer 2: Osteotomy is considered once the child is skeletally mature or not enough growth remains for guided-growth.
Answer 4: The patient has bilateral disease, so a unilateral correction is not sufficient.
Answer 5: This will worsen her deformity.