STRYDE versus PRECICE magnetic internal lengthening nail for femur lengthening

Arch Orthop Trauma Surg. 2022 Dec;142(12):3555-3561. doi: 10.1007/s00402-021-03943-8. Epub 2021 May 13.

Abstract

Introduction: Magnetic internal lengthening nails (MILNs) have been used for femoral lengthening to avoid complications associated with external fixation. The titanium version of the MILN (PRECICE®) has been in use since 2011 but had limitations (50-75 lb) in post-operative weight bearing. A new stainless-steel version of the MILN (STRYDE®) allows 150-250 lb of post-operative weight bearing. The aim is to compare the outcomes of using these two different MILNs for both unilateral and bilateral femoral lengthening.

Methods: A single-center, retrospective cohort study was conducted in which patients' records were reviewed from the period from January 2017 to March 2020. A total of 66 femoral lengthening procedures were included in the study and were divided into two groups: STRYDE® group (30 femora) and PRECICE® group (36 femora). Outcomes assessed were the 6-months post-operative Limb Deformity-Scoliosis Research Society (LD-SRS) Score, adjacent joint range of motion (ROM), average distraction rate, bone healing index (BHI), and complications.

Results: No statistically significant difference was found between the two groups in regard to the (LD-SRS) score, hip ROM, or knee ROM. Statistically significant differences were found between the two groups in regard to BHI (average of 0.84 months/cm and 0.67 months/cm for STRYDE® and PRECICE®, respectively) and distraction rate (average of 0.6 mm/day and 0.9 mm/day for STRYDE® and PRECICE®, respectively). No mechanical nail complications were reported in the STRYDE® group compared to three events of nail failure in the PRECICE® group. One femur in the PRECICE® group needed BMAC injection for delayed healing compared to four femurs in the STRYDE® group.

Conclusion: The STRYDE® MILN yields comparable functional results to those of PRECICE® MILN and shows fewer mechanical nail complications. However, STRYDE® MILN requires a slower distraction rate and yields slower healing (larger BHI).

Level of evidence: Level III, Therapeutic study.

Keywords: Femur; Intramedullary; Lengthening; PRECICE®; STRYDE®.

MeSH terms

  • Bone Lengthening* / methods
  • Bone Nails / adverse effects
  • Femur / surgery
  • Humans
  • Leg Length Inequality / etiology
  • Leg Length Inequality / surgery
  • Magnetic Phenomena
  • Nails
  • Retrospective Studies
  • Steel
  • Titanium
  • Treatment Outcome

Substances

  • Titanium
  • Steel