Pitfalls in Automatic Limb Lengthening - First Results with an Intramedullary Lengthening Device

Background: The treatment of leg length discrepancy and deformities has become more common over the last few decades due to newly developed implants. Lengthening using fully implantable intramedullary nails provides many advantages; however, only little data is available. Therefore, we aimed to determine: (1) safety of the implant, (2) the complication rate and (3) functional outcome after magnetic driven intramedullary bone lengthening with a telescopic implant.

Hypotheses: Automatic bone lengthening with intramedullary nails provide good short-term outcome.

Patients And Methods: Ten patients with limb length discrepancy of lower extremity, treated with an Ellipse PRECICE nail, were included in this retrospective follow-up study. The mean limb length discrepancy was 4.7cm (range: 2.5-7.0cm).

Results: In all patients, limb lengthening goals were reached within a range of ±0.5cm after a mean time of 53 days. However, in 2 patients, mechanical failures with unintended shortening were observed. In a further patient nail breakage occurred. Overall, 7 patients presented with complications during the follow-up period.

Discussion: The PRECICE nail represents a new, fully implantable, magnetically driven device for limb lengthening. However, due to a high rate of complications, a close follow-up is necessary to identify early implant failures and to avoid severe adverse outcomes.

Level Of Evidence: Retrospective follow-up study, case series, level IV.