SYSTEMATIC REVIEW OF SURGICAL INDICATIONS FOR TIBIAL DEROTATIONAL OSTEOTOMY

Abstract

Background: Tibial torsion is a lower extremity disorder of children and adolescents that may be idiopathic in nature. While spontaneous correction of the torsion occurs in the majority of patients during childhood, a small percentage of cases will persist into adulthood and can be associated with significant functional compromise due to patellofemoral instability, osteoarthritis, and anterior knee pain. Furthermore, late detection of tibial torsion may lead to compromise of other therapeutic efforts to alleviate symptoms. Idiopathic tibial torsion is best corrected by a tibial derotational osteotomy. However, determining which patients may benefit most from surgical correction is not well-understood, given the wide range of accepted values for normal tibial torsion depending on various measurement techniques. This review seeks to establish surgical indications for the procedure in a pediatric population with no underlying neurological, muscular, or osseous abnormalities. Methods: Systematic literature searches of 10 major databases and grey literature resources were conducted (Medline and Embase (via OVID), Cochrane Library, SPORTDiscus, Web of Science, Scopus, ClinicalTrials.gov, WHO ICTRP, and Global Index). Studies were screened by two independent reviewers based on previously established inclusion and exclusion criteria. Articles that focused on non-idiopathic torsion, such as torsion associated with neuromuscular causes, or that did not involve derotational osteotomy were excluded. Included studies were assessed for bias by two independent reviewers using GRADE and the Newcastle Ottawa Scale. Results: 911 articles were retrieved through the searches, 16 of which were ultimately included in the study. Due to the rarity of the condition, most authors studied a mixed population of skeletally mature and immature patients, except for one study. The most common surgical indications described were functional gait or cosmetic disability (70%), followed by patellofemoral instability and anterior knee pain (30%). Only a few articles cited numerical limits of abnormal torsion, and these depended on the method of measurement. Thigh-foot angle (TFA) was most often used (external torsion > 30°, internal torsion > 15°, and TFA > 2 or 3 standard deviations from the mean for the patient’s age). A bimalleolar axis with <20° external rotation was deemed excessively internally rotated. No numerical data was provided for defining abnormal foot-progression angle. Almost all authors recommended waiting until a patient was greater than 8 years old to allow for spontaneous correction of tibial torsion. Only two studies utilized computed tomography for pre- and post-operative assessment, given the cost of advanced imaging, and two other authors measured with gait analysis the effect of derotational tibial osteotomies on knee moments and ankle power. Conclusion/Significance: The diversity of measurement techniques and different anatomic references axes for describing tibial torsion has translated into a heterogenous set of surgical indications for tibial derotational osteotomies. At this time, the literature suggests that most correction procedures are decided by a patient’s functional and/or cosmetic disability. Further research is warranted to define clear standards and numerical values of tibial torsion that would benefit from surgical correction.