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Changes in the femoral osteotomy level coefficient and neck shaft angle during limb lengthening with an intramedullary magnetic nail

  • Orthopaedic Surgery
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Archives of Orthopaedic and Trauma Surgery Aims and scope Submit manuscript



The intramedullary magnetic IM nail enables bone graduated distraction. Proximal femur osteotomies for ante grade IM lengthening nails have a tendency towards varus-procurvatum malalignment. We examined the effect of the level of the osteotomy and of trochanteric versus piriformis entry points on the neck shaft angle (NSA) during lengthening with the PRECICE IM magnetic nail.


A novel parameter, the osteotomy level coefficient (OLC), was introduced as a guide to determine the level of an osteotomy at the proximal femur. The OLC was defined as the ratio between the distances from the tip of the greater trochanter to the osteotomy divided by the full length of the femur. A retrospective review of all femoral lengthening procedures with the PRECICE ante grade IM lengthening nail between 2013 and 2018 was carried out.


31 femurs were lengthened in 30 patients (16 males and 14 females, mean age at surgery years 17.1. The average amount of lengthening was 4.4 cm. Trochanteric entry points were used in 24 femurs, and piriformis entry points in seven femurs. The OLC values ranged from 0.16 to 0.34 (average 0.25). The average follow-up period was 10.15 months. The distraction index average 10.5 days/cm (Range 8.6–11.9), Consolidation index 32.1 days/cm (14.3–51.9). The average post-operative NSA was significantly reduced from 133.5º to 128.5º [t (31) = 5.57, p = 0.000]. There was no correlation between the OLC and the change in the NSAs. The trochanteric entry point showed a greater tendency to reduce the NSA (Mdif = − 6, SD = 4.8) compared to the piriformis entry point (Mdif =  − 0.86, SD = 2.27) [t (31) = -3.96, p = 0.001].


Proximal femur lengthening with the PRECICE IM nail significantly reduced the NSA and might cause Varus deformity. The level of osteotomy by OLC did not influence the amount of NSA reduction. The trochanteric entry points have a greater tendency to reduce the NSA compared to the piriformis entry points.

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  1. Calder PR, Laubscher M, Goodier WD (2017) The role of the intramedullary implant in limb lengthening. Injury 48(1):S52–S58

    Article  Google Scholar 

  2. Fragomen AT, Wellman D, Rozbruch SR (2019) The PRECICE magnetic IM compression nail for long bone nonunions: a preliminary report. Arch Orthop Trauma Surg 139:1551–1560

    Article  Google Scholar 

  3. Paley D (2015) PRECICE intramedullary limb lengthening system. Expert Rev Med Dev 12(3):231–249

    Article  CAS  Google Scholar 

  4. Laubscher M, Mitchell C, Timms A, Goodier D, Calder P (2016) Outcomes following femoral lengthening: an initial comparison of the Precice intramedullary lengthening nail and the LRS external fixator monorail system. Bone Jt J 98(10):1382–1388

    Article  Google Scholar 

  5. Wagner P, Burghardt RD, Green SA, Specht SC, Standard SC, Herzenberg JE (2017) PRECICE® magnetically-driven, telescopic, intramedullary lengthening nail: pre-clinical testing and first 30 patients. SICOT J 3:19

    Article  Google Scholar 

  6. Fragomen AT, Kurtz AM, Barclay JR, Nguyen J, Rozbruch SR (2018) A comparison of femoral lengthening methods favors the magnetic internal lengthening nail when compared with lengthening over a nail. HSS J 14(2):166–176

    Article  Google Scholar 

  7. Paley D (1990) Problems, obstacles, and complications of limb lengthening by the Ilizarov technique. Clin Orthop Relat Res 250:81–104

    Google Scholar 

  8. Paley D, Herzenberg JE, Paremain G, Bhave A (1997) Femoral lengthening over an intramedullary nail. A matched-case comparison with Ilizarov femoral lengthening. J Bone Joint Surg Am 79(10):1464–1480

    Article  CAS  Google Scholar 

  9. Schiedel F (2020) Extracorporal noninvasive acute retraction of STRYDE® for continued lengthening in cases with limited nail stroke: a technical less invasive solution to reload the STRYDE®. Arch Orthop Trauma Surg. (Published online ahead of print, May 26 2020)

  10. Burghardt RD, Herzenberg JE, Burghardt MH (2011) Trigonometric analysis of the mechanical axis deviation induced by telescopic intramedullary femoral lengthening nails. J Appl Biomech 27(4):385–391

    Article  Google Scholar 

  11. Burghardt RD, Paley D, Specht SC, Herzenberg JE (2012) The effect on mechanical axis deviation of femoral lengthening with an intramedullary telescopic nail. J Bone Joint Surg Br 94(9):1241–1245

    Article  CAS  Google Scholar 

  12. Guichet JM, Deromedis B, Donnan LT, Peretti G, Lascombes P, Bado F (2003) Gradual Femoral Lengthening with the Albizzia Intramedullary Nail. J Bone Joint Surg Am 85(5):838–848

    Article  Google Scholar 

  13. García-Cimbrelo E, Curto de la Mano A, García-Rey E, Cordero J, Marti-Ciruelos R (2002) The intramedullary elongation nail for femoral lengthening. J Bone Joint Surg Br 84(7):971–977

    Article  Google Scholar 

  14. Singh S, Lahiri A, Iqbal M (2006) The results of limb lengthening by callus distraction using an extending intramedullary nail (Fitbone) in non-traumatic disorders. J Bone Joint Surg Br 88(7):938–942

    Article  CAS  Google Scholar 

  15. Kirane YM, Fragomen AT, Rozbruch SR (2014) Precision of the PRECICE ® internal bone lengthening nail. Clin Orthop Relat Res 472(12):3869–3878

    Article  Google Scholar 

  16. Emara KM, Mahmoud AN, Emara AK, Emara MK (2017) Effect of lengthening along the anatomical axis of the femur and its clinical impact. World J Orthop 8(5):431–435

    Article  Google Scholar 

  17. Hawi N, Kenawey M, Panzica M, Stuebig T, Omar M, Krettek C, Liodakis E (2015) Nail-medullary canal ratio affects mechanical axis deviation during femoral lengthening with an intramedullary distractor. Injury 46(11):2258–2262

    Article  Google Scholar 

  18. Segev E, Hemo Y, Wientroub S et al (2010) Intra- and interobserver reliability analysis of digital radiographic measurements for pediatric orthopedic parameters using a novel PACS integrated computer software program. J Child Orthop 4(4):331–341

    Article  Google Scholar 

  19. Kumar P, Neradi D, Kansal R, Aggarwal S, Kumar V, Dhillon MS (2019) Greater trochanteric versus piriformis fossa entry nails for femur shaft fractures: resolving the controversy. Injury 50(10):1715–1724

    Article  Google Scholar 

  20. Yun HH, Oh CH, Yi JW (2013) Subtrochanteric femoral fracture during trochanteric nailing for the treatment of femoral shaft fracture. Clin Orthop Surg 5(3):230–234

    Article  Google Scholar 

  21. Sadagatullah AN, Nazeeb MN, Ibrahim S (2017) Incidence of varus malalignment post interlocking nail in proximal femur shaft fractures comparing two types of entry points. Malays Orthop J 11(3):31–35

    Article  CAS  Google Scholar 

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Correspondence to Eitan Segev.

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Gigi, R., Hemo, Y., Danino, B. et al. Changes in the femoral osteotomy level coefficient and neck shaft angle during limb lengthening with an intramedullary magnetic nail. Arch Orthop Trauma Surg 142, 1739–1742 (2022).

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