Use of Hexapod External Fixation in Limb Lengthening in Patients with Disproportionate Short Stature: A Systematic Review of the Last 20 Years

Background: Limb lengthening is a surgical procedure intended to correct discrepancies and deformities in limb length or to enhance limb length for functional or cosmetic reasons. Short stature, often seen as a physical condition, can significantly affect a patient's quality of life. The advancement of limb lengthening methods, including the creation of hexapod external fixation systems, has heightened the precision and efficacy of these procedures. The Taylor spatial frame (TSF), a form of hexapod external fixator, grants three-dimensional control of bone movement and is increasingly used to rectify deformities and lengthen limbs. This systematic review aims to assess the effectiveness of the hexapod external fixator in limb lengthening and deformity correction compared to other external fixation systems, focusing on outcomes such as achieved lengthening, healing index, complications, and follow-up duration. Methods: A structured search was engineered in four crucial search engines (PubMed, Scopus, Web of Science, and Medline) spanning 2004 to 2024. Results: The studies included in this review indicate that the average lengthening accomplished with the hexapod fixator ranged from 3 to 5.9 cm, with a healing index between 37 and 68.6 days/cm. The most frequent complications were pin site infections, compartment syndrome, and delayed union. The follow-up duration ranged from 6.8 months to 6 years. These studies also compared the hexapod external fixator with other external fixators, showing that while the TSF allowed more accurate deformity corrections, it often displayed a higher healing index. Conclusions: The hexapod external fixator, specifically the TSF, is an effective instrument for limb lengthening and deformity correction in patients with short stature. Although it provides superior three-dimensional control for deformity correction, the healing index and treatment duration can be longer compared to traditional external fixators. Further studies with larger sample sizes and extended follow-up are needed to perfect treatment protocols and thoroughly evaluate the long-term outcomes and complications associated with this technique.