Tibial lengthening using a retrograde magnetically driven intramedullary lengthening device in 10 patients with preexisting ankle and hindfoot fusion

Abstract

Background and purpose — Motorized intramedullary lengthening nails (ILNs) have been developed as an alternative to external fixators for long bone lengthening. The antegrade approach represents the standard method for tibial ILN insertion. In patients with preexisting ankle and hindfoot fusion a retrograde approach provides an alternative technique that has not been evaluated so far. We report the outcome of this method in 10 patients. Patients and methods — This retrospective study included 10 patients (mean age 18 years [13–25]) with preexisting ankle and hindfoot fusion who underwent tibial lengthening with a retrograde ILN (PRECICE). The mean leg length discrepancy (LLD) was 58 mm (36–80). The underlying conditions were congenital (n = 9) and post tumor resection (n = 1). The main outcome measures were: ILN reliability, distraction achieved, distraction index (DIX), time to bone healing, consolidation index (CIX), complications, and functional results. Results — All patients achieved the goal of lengthening (mean 48 mm [26–80]). Average DIX was 0.6 mm/day (0.5–0.7) and mean CIX was 44 days/cm (26–60). Delayed consolidation occurred in 2 patients and healed after ILN dynamization or nail exchange with grafting. Toe contractures in 2 other patients were resolved with physiotherapy or tenotomy. Until last follow-up (mean 18 months [12–30]) no true complications were encountered, knee motion remained unaffected, and full osseous consolidation occurred in all patients. Interpretation — In patients with LLD and preexisting ankle and hindfoot fusion distal tibial lengthening using a retrograde ILN is a reliable alternative to the standard approach with equivalent bone healing potential and low complication rates leaving the knee unaffected.

What Are the Potential Benefits and Risks of Using Magnetically Driven Antegrade Intramedullary Lengthening Nails for Femoral Lengthening to Treat Leg Length Discrepancy?

“…Temporary joint stiffness remains a common complication of intramedullary lengthening. Although limb lengthening with magnetically driven lengthening nails seems reliable in terms of achieving the desired length of distraction [5,13,19,26,27], an unplanned additional surgical procedure remains a serious complication, even if treatment concludes without new pathologic findings or permanent sequelae. A recent systematic review of treatment with externally controlled lengthening nails has shown that complications can occur in one of three patients even though ultimately the treatment goal is still achieved [9].…”

“…Our results confirm that magnetically driven intramedullary lengthening nails are reliable for straight femoral lengthening, with nail insertion via an antegrade approach for lengthening of the femur along its anatomical axis. For standardized reporting and better comparability of lengthening parameters, we argue in favor of an implant-referenced measurement technique [27]. Wagner et al [29] reported an accuracy of 97% with a precision of 92%, while Nasto et al [19] found an accuracy of 91%.…”

Focal osteolysis and corrosion at the junction of Precice Stryde intramedullary lengthening device

“…1 , 2 , 22 Several previous studies have found limb lengthening with magnetically driven motorized ILNs to be safe and reliable. 10 , 12 , 13 , 23 …”

“… 5 - 7 In particular, magnetically driven ILNs have become increasingly popular over the last decade. 8 - 13 The Precice Stryde (Stryde) nail (NuVasive Specialized Orthopedics, USA) was approved by the USA Food and Drug Administration in April 2018 and received European CE certification in February 2019. The major difference in comparison to precedent implants such as the second-generation Precice ILN (P2) (NuVasive Specialized Orthopedics), 14 the intramedullary skeletal kinetic distractor (Orthofix, USA), 4 or the Fitbone nail 5 (Orthofix) lies in the change of implant design and material.…”

An Update on the Intramedullary Implant in Limb Lengthening: A Quinquennial Review Part 2: Extending Surgical Indications and Further Innovation

“…Wright et al [12] , in a case series of 17 consecutive patients, used a latency period of six days and lengthened at a rate of 0.33 mm twice per day, with no non-unions, no premature consolidation and a median healing index of 38.05 days/cm. Vogt et al [15] describe their outcomes following tibial lengthening in patients with a previous hind foot fusion using a retro-grade straight Precice nail. The study included 10 patients, with multiple aetiologies including fibular hemimelia (4 cases), tibial hemimelia (2), clubfoot (1), post osteosarcoma resection (1), pes calcaneus in caudal regression syndrome (1), and nail-patella syndrome (1).…”