[Application of motorized intramedullary lengthening nails in skeletally immature patients : Indications and limitations]. / Anwendung motorisierter Verlängerungsmarknägel am wachsenden Skelett : Indikationsspektrum und Limitationen.

BACKGROUND: Limb lengthening and deformity correction with motorized intramedullary lengthening nails is a more comfortable and equally safe procedure than the use of external fixators. While this treatment is a well-established method in adults, intramedullary nailing for skeletally immature patients remains a challenge and is the focus of current clinical investigations. OBJECTIVE: Elucidation of the indications for the application of femoral and tibial lengthening nails in skeletally immature patients, presentation of essential characteristics and limitations of the treatment. MATERIAL AND METHODS: Treatment of skeletally immature patients up to 16 years old who had a lengthening nail inserted was retrospectively clinically and radiologically evaluated (2016-2018). RESULTS: A total of 60 procedures were performed on 54 patients. Mean age at the time of surgery was 13.6 years and the mean follow-up time was 10 months. Different nailing approaches were used: antegrade femoral (n = 42), retrograde femoral (n = 10) and antegrade tibial (n = 8). The average amount of lengthening was 45 mm. In 58 of the 60 cases (96.7%) the desired amount of lengthening was achieved, while 2 patients experienced complications that required interruption of the treatment. None of the patients developed growth disorders associated with the nailing approach. CONCLUSION: Different approaches for intramedullary lengthening nails can be used in children and adolescents to correct leg length discrepancy with or without concomitant deformities. The treatment is limited by the size of the available nails, the residual growth and extent of the deformity. Larger trials will be needed to further validate the application of lengthening nails in skeletally immature patients.