Intramedullary leg lengthening with a motorized nail

Abstract

Background and purposeIn the last decade, intramedullary limb lengthening has become a viable alternative to traditional external systems. We retrospectively analyzed the use of an intramedullary motorized nail (Fitbone) in a consecutive series of 32 patients.Patients and methodsDuring the period September 2006 to December 2008, 32 consecutive patients with a median age of 17 (IQR: 15–19) years were treated with a fully implantable, motorized intramedullary lengthening device (Fitbone). The median leg length discrepancy was 35 (IQR: 30–44) mm at the femur (n = 21) and 28 (IQR: 25–30) mm at the tibia (n = 11).ResultsLeg lengthening was successful in 30 of 32 cases, with no residual relevant discrepancy (± 5 mm). No intraoperative complications were observed. The consolidation index was significantly different (p = 0.04) between femoral lengthening (mean 35 days/cm) and tibial lengthening (mean 48 days/cm) but did not depend on age older/younger than 16 or previous operations at the affected site. 3 problems, 3 obstacles, and 4 complications (3 minor, 1 major) were encountered in 8 patients, 5 of which were implant-associated.InterpretationThis technique even allows correction in patients with multiplanar deformities. Compared to external devices, intramedullary systems provide comfort and reduce complication rates, give improved cosmetic results, and lead to fast rehabilitation since percutaneous, transmuscular fixation is prevented. This results in reasonable overall treatment costs despite the relatively high costs of implants.

Internal Lengthening Device for Congenital Femoral Deficiency and Fibular Hemimelia

“…When comparing the accuracy of other methods of lengthening, we found that other intramedullary devices presented with more difficulty in controlling the rate of distraction, resulting in premature or delayed consolidation [16,[20][21][22]35]. Kenawey et al [20] reported an overall incidence of complications of 33%, of which the most important was insufficient bone regenerate (21%) and nine runaway nails.…”

“…For the past 10 years, the only FDA-approved intramedullary lengthening device has been the Intramedullary Skeletal Kinetic Distractor (ISKD) (Orthofix Inc, Lewisville, TX, USA). However, intramedullary lengthening is associated with complications, including premature or delayed consolidation with difficulty in controlling the rate of distraction, implant breakage, and mechanical failure [9,16,[20][21][22]35].…”

Current concepts of leg lengthening

“…2 cm to max. 17.4 cm) for Ilizarov ring fixators (IRF) [48,57,58] and intramedullary nails [16,46,50,[59][60][61][62][63][64] and around 2.5-3 cm (min. 8 mm to max.…”

“…There seems not to be a difference between femoral and tibial lengthenings, not between congenital and acquired problems but higher age, severity of deformity, unilateral fixation and amount of acute correction may have some additional negative impact [13,154]. The figures for complications according to Paley [22] are biased, since IRF and TSF are commonly used for more complex cases: they range from 46 to 72 % for external fixation [13,17,22], up to 60 % for LON [60], are around 29 % [16,49] for Albizzia nails, 31-50 % [51,55] for ISKD and 12.5-27 % [56,63] for Fitbone nails.…”

Distraction osteogenesis using a longitudinal corticotomy

“…This technique allowed them to remove the external fixator early, but healing still occurred at 48 days/cm. Healing rates following lengthening over an intramedullary nail are reported between 37 and 48 days/cm [9,11]. Future comparative studies are necessary to evaluate outcomes of these techniques relative to the longitudinal corticotomy technique described in the our study.…”