Aims: As an alternative to external fixators, intramedullary lengthening nails (ILNs) can be employed for distraction osteogenesis. While previous studies have demonstrated that typical complications of external devices, such as soft-tissue tethering, and pin site infection can be avoided with ILNs, there is a lack of studies that exclusively investigated tibial distraction osteogenesis with motorized ILNs inserted via an antegrade approach.
Methods: A total of 58 patients (median age 17 years (interquartile range (IQR) 15 to 21)) treated by unilateral tibial distraction osteogenesis for a median leg length discrepancy of 41 mm (IQR 34 to 53), and nine patients with disproportionate short stature treated by bilateral simultaneous tibial distraction osteogenesis, with magnetically controlled motorized ILNs inserted via an antegrade approach, were retrospectively analyzed. The median follow-up was 37 months (IQR 30 to 51). Outcome measurements were accuracy, precision, reliability, bone healing, complications, and patient-reported outcome assessed by the Limb Deformity-Scoliosis Research Society Score (LD-SRS-30).
Results: A median tibial distraction of 44 mm (IQR 31 to 49) was achieved with a mean distraction index of 0.5 mm/day (standard deviation 0.13) and median consolidation index of 41.2 days/cm (IQR 34 to 51). Accuracy, precision, and reliability were 91%, 92%, and 97%, respectively. New temporary range of motion limitations occurred in 51% of segments (34/67). Distraction-related equinus deformity treated by Achilles tendon lengthening was the most common major complication recorded in 16% of segments (11/67). In 95% of patients (55/58) the distraction goal was achieved with 42% unplanned additional interventions per segment (28/67). The median postoperative LD-SRS-30 score was 4.0 (IQR 3.6 to 4.3).
Conclusion: Tibial distraction osteogenesis using motorized ILNs inserted via an antegrade approach appears to be a reliable and precise procedure. Temporary joint stiffness of the knee or ankle should be expected in up to every second patient. A high rate and wide range of complications of variable severity should be anticipated.
Competing Interests: B. Vogt reports grants or contracts from NuVasive and Smith & Nephew, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events and support for attending meetings and/or travel from NuVasive, OrthoPediatrics, Smith & Nephew, BioMarin, Orthofix, Kyowa Kirin, and Merete, all of which are unrelated to this article. A. Laufer reports support for attending meetings and/or travel from BioMarin, NuVasive, and Implantcast, all of which are unrelated to this article. C. Antfang reports support for attending meetings and/or travel from BioMarin and Smith & Nephew, unrelated to this article. R. Roedl reports institutional grants or contracts from NuVasive, royalties or licenses and patents planned, issued or pending from Merete, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from NuVasive, BioMarin, Kyowa Kirin, Vereinigung für Kinderorthopädie, Forum für medizinische Fortbildung, and Infectopharm, all of which are unrelated to this article. A. Frommer reports grants or contracts and support for attending meetings and/or travel from NuVasive, unrelated to this article.
(© 2024 The British Editorial Society of Bone & Joint Surgery.)