New Single-stage Double Osteotomy for Late-presenting Infantile Tibia Vara

BACKGROUND:: Successful surgical treatment of late-presenting infantile tibia vara (ITV) patient requires the correction of oblique deformities. The purpose of this study was to report on a new comprehensive approach to correct and prevent recurrence of these deformities with a single procedure. METHODS:: Medical records of 23 consecutive children (7 to 18 y) with advanced ITV (29 knees) were retrospectively reviewed after a mean of 7.3 years postoperatively (range, 2 to 22 y). Indications for the corrective surgery were any child 7 year or older with a varus mechanical axis angle ≥10 degrees or a varus anatomic axis angle ≥11 degrees and a medial tibial angle (MTA) slope <60 degrees. The deformities were corrected with a dome-shaped osteotomy proximal to the tibial tubercle with a midline vertical extension to the subchondral region of the joint and a lateral hemi-epiphysiodesis. RESULTS:: At latest follow-up, means and medians of each tibial radiographic axis measurement improved significantly from preoperative values (P<0.001): mechanical axis angle from 23 degrees to 4 degrees varus, anatomic axis angle from 25 degrees varus to 1 degree valgus, MTA downward slope from 30 to 78 degrees, posterior MTA from 59 to 80 degrees. In total, 79% and 74% had good to excellent results based on radiographic criteria and clinical questionnaire for satisfaction, pain and function, respectively. Two abnormal medial tibial plateau types were described. CONCLUSIONS:: This is the first study to use a single-stage double osteotomy performed proximal to the tibial tubercle for the late-presenting ITV for children 7 years of age or older. In addition to the effective correction of the 4 major tibial deformities, a lateral proximal tibial hemi-epiphysiodesis minimizes recurrence of tibia vara. A contralateral proximal tibial epiphysiodesis is recommended for treated skeletally immature patients with unilateral disease. LEVEL OF EVIDENCE:: Therapeutic level IV. See instructions for authors for a complete description of levels of evidence.