The Journal of Bone and Joint Surgery (American). 2009;91:2873-2879.
doi:10.2106/JBJS.H.01245
© 2009 The Journal of Bone and Joint Surgery, Inc.
Treatment of Adolescent Tibia Vara with Hemiepiphysiodesis: Risk Factors for Failure
Amy L. McIntosh, MD1,
Chad M. Hanson, MD2 and
Karl E. Rathjen, MD3
1 Department of Orthopedic Surgery, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905
2 Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390
3 Department of Orthopedic Surgery, Texas Scottish Rite Hospital for Children, 2222 Welborn Street, Dallas, TX 75219. E-mail address: Karl.Rathjen{at}tsrh.org
Investigation performed at Texas Scottish Rite Hospital for Children, Dallas, Texas
Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.
Background: Lateral tibial hemiepiphysiodesis is an accepted surgical treatment for skeletally immature patients with adolescent tibia vara. However, the results of this procedure are unpredictable. This study was conducted to identify the risk factors associated with failure of hemiepiphysiodesis.
Methods: We studied patients with adolescent tibia vara who were at least ten years of age, had open physes, had been treated with a lateral hemiepiphysiodesis, and had been followed for at least two years. The mechanical axis deviation, medial proximal tibial angle, and lateral distal femoral angle were measured on radiographs preoperatively, at six months postoperatively, and at the time of final follow-up. Failure was defined as a residual varus deformity requiring osteotomy or a mechanical axis deviation exceeding 40 mm (moderate or severe varus) at the time of final follow-up.
Results: Forty-nine patients (forty-six male) with a total of sixty-four involved extremities met the inclusion criteria. The average age was 13.4 years, the average body mass index was 40.7 kg/m2, and the average duration of follow-up was 3.3 years. The lateral hemiepiphysiodesis was unsuccessful in 66% of the patients. In a multivariate Cox proportional hazards regression analysis, the variables associated with a higher risk of failure included an age of fourteen years or more (hazard ratio = 3.9, p = 0.0009) and a body mass index of 45 kg/m2 (hazard ratio = 2.8, p = 0.01). Greater deformity at baseline as indicated by a smaller medial proximal tibial angle was also found to be a significant factor in the multivariate analysis (p = 0.03).
Conclusions: Lateral hemiepiphysiodesis may be a valuable treatment option for non-morbidly obese patients with less severe adolescent tibia vara, but it is likely to fail in older adolescents with a high body mass index and greater deformity.
Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

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