An Abnormal Presentation of Pediatric Genu Varum, Managed by Bilateral Tibial and Fibular Osteotomies With External Spatial Frame Placement: A Case Report

Abstract

Genu varum is a common finding in the pediatric population with a large differential, including but not limited to Blount's disease, rickets, and physiologic bowing of the legs. Here we report a case of a 12-year-old Caucasian male who presented for an atraumatic stress fracture of the fifth metatarsal after an athletic event. Further evaluation showed significant genu varum with a Q angle of 9 degrees and medial knee joint space narrowing. The patient was unable to undergo conservative management due to early completion of puberty with relatively premature skeletal maturity. A bilateral tibial and fibular osteotomy with external spatial frame placement was performed successfully followed by six months of minor activity complicated by subclinical enoxaparin-induced purpura. The unique presentation of a stress fracture caused by compensatory mechanisms for the severe varus deformity, as well as the rarity of this procedure being performed on both legs simultaneously with good outcomes was the primary reason for the publication of this paper.

Keywords: genu varum; minimally invasive osteotomy; pediatric stress fracture; taylor spatial frame; tibial osteotomy.

Figure 1. Bilateral lower extremity bowing noted on physical exam

Figure 2. Pre-operative lower extremity X-ray showing the varus deformity bilaterally

Figure 3. Post-operative X-ray of the lower extremity showing correction of the varus deformity