Hip Pelvis.  2017 Jun;29(2):104-112. 10.5371/hp.2017.29.2.104.

Radiographic Outcomes of Osteosynthesis Using Proximal Femoral Nail Antirotation (PFNA) System in Intertrochanteric Femoral Fracture: Has PFNA II Solved All the Problems?

• Shin WC
• Seo JD
• Lee SM
• Moon NH
• Lee JS
• Suh KT

• KMID: 2424238
• DOI: http://doi.org/10.5371/hp.2017.29.2.104

Abstract

PURPOSE
We evaluated the geometric discrepancies between the proximal femur in Koreans and two types of proximal femoral nail using plain radiographs.
MATERIALS AND METHODS
A total of 100 consecutive patients (38 treated with proximal femoral nail antirotation [PFNA], 62 PFNA II) with intertrochanteric fracture were retrospectively identified. The minimum follow up period was 32 months. The geometric analysis of the proximal femur was performed using preoperative true hip antero-posterior radiographs of the unaffected side, and the data were compared with the PFNA and PFNA II dimensions. Postoperative assessments were performed using postoperative radiographs for the proximal protruding length of nail tip, quality of reduction, implant position and the presence of lateral cortical impingement.
RESULTS
The geometric dimensions of the proximal femur were different between the two proximal femoral nail types. No impingement was detected in patients treated with PFNA II, whereas 13 cases of lateral impingement were observed in patients treated with PFNA. A significant association was observed between the short proximal femur and the presence of lateral cortical impingement (P=0.032) and between impingement and intraoperative reduction loss (P=0.012). Proximal protrusion of the nail tip was seen in 71 patients and no difference was observed between two groups.
CONCLUSION
Our study demonstrates that the flat lateral surface of PFNA II can avoid lateral cortical impingement, which provide better fixation for intertrochanteric fracture. However, there was still a problem associated with longer proximal end of PFNA II compared with the proximal femoral length in Korean.

Keyword

Intertrochanteric fracture; Lateral cortical impingement; Proximal femoral nail antirotation; Korean

MeSH Terms

Femoral Fractures*
Femur
Follow-Up Studies
Hip
Humans
Retrospective Studies

Figure

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  Fig. 1 This picture demonstrates the measuring method of the geometry of the proximal femur. Proximal femoral length (PFL) was the distance between the tip of the greater trochanter and the crossing point, which was made between femoral shaft axis and line drawn at 130° to the femoral shaft axis from the inferior margin of the femoral neck (central line of the proximal femur). The anteroposterior bending angle (APBA) was formed by the femoral shaft line and a line between the greater trochanteric tip and the crossing point. Arrow indicates the impingement point.

• 

  Fig. 2 Postoperative radiograph (A) shows anatomical mismatch between the proximal femur of the patient and proximal femoral nail antirotation (PFNA), and lateral cortical impingement (arrow). Postoperative radiograph (B) shows good alignment without lateral cortical impingement between the proximal femur of the patient and PFNA II. Illustrations were sourced by a manual of PFNA and PFNA II15).

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  Fig. 3 (A) This preoperative anteroposterior radiograph illustrates an unstable intertrochanteric fracture of the femur with subtrochanteric extension in a 45-year-old woman. (B) Postoperative radiograph after using proximal femoral nail antirotation shows loss of reduction at the fracture site (arrow) with lateral cortical impingement.

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  Fig. 4 (A) This preoperative anteroposterior radiograph illustrates an unstable intertrochanteric fracture of the femur in a 68-year-old woman. (B) Postoperative radiograph after using proximal femoral nail antirotation shows lateral wall fracture (arrow) during nail insertion.

Reference

1. Gardenbroek TJ, Segers MJ, Simmermacher RK, Hammacher ER. The proximal femur nail antirotation: an identifiable improvement in the treatment of unstable pertrochanteric fractures? J Trauma. 2011; 71:169–174.

2. Garg B, Marimuthu K, Kumar V, Malhotra R, Kotwal PP. Outcome of short proximal femoral nail antirotation and dynamic hip screw for fixation of unstable trochanteric fractures. A randomised prospective comparative trial. Hip Int. 2011; 21:531–536.

3. Strauss E, Frank J, Lee J, Kummer FJ, Tejwani N. Helical blade versus sliding hip screw for treatment of unstable intertrochanteric hip fractures: a biomechanical evaluation. Injury. 2006; 37:984–989.

4. Xu YZ, Geng DC, Mao HQ, Zhu XS, Yang HL. A comparison of the proximal femoral nail antirotation device and dynamic hip screw in the treatment of unstable pertrochanteric fracture. J Int Med Res. 2010; 38:1266–1275.

5. Verettas DA, Ifantidis P, Chatzipapas CN, et al. Systematic effects of surgical treatment of hip fractures: gliding screw-plating vs intramedullary nailing. Injury. 2010; 41:279–284.

6. Macheras GA, Koutsostathis SD, Galanakos S, Kateros K, Papadakis SA. Does PFNA II avoid lateral cortex impingement for unstable peritrochanteric fractures? Clin Orthop Relat Res. 2012; 470:3067–3076.

7. Tao YL, Ma Z, Chang SM. Does PFNA II avoid lateral cortex impingement for unstable peritrochanteric fractures? Clin Orthop Relat Res. 2013; 471:1393–1394.

8. Tyagi V, Yang JH, Oh KJ. A computed tomography-based analysis of proximal femoral geometry for lateral impingement with two types of proximal femoral nail anterotation in subtrochanteric fractures. Injury. 2010; 41:857–861.

9. Cooper C, Campion G, Melton LJ 3rd. Hip fractures in the elderly: a world-wide projection. Osteoporos Int. 1992; 2:285–289.

10. Kim DS, Shon HC, Kim YM, Choi ES, Park KJ, Im SH. Postoperative mortality and the associated factors for senile hip fracture patients. J Korean Orthop Assoc. 2008; 43:488–494.

11. Müller ME, Nazarian S, Koch P, Schatzker J. The comprehensive classification of fractures of long bones. Berlin, Heidelberg, New York: Spinger-Verlag;1990.

12. Boldin C, Seibert FJ, Fankhauser F, Peicha G, Grechenig W, Szyszkowitz R. The proximal femoral nail (PFN)--a minimal invasive treatment of unstable proximal femoral fractures: a prospective study of 55 patients with a follow-up of 15 months. Acta Orthop Scand. 2003; 74:53–58.

13. Baumgaertner MR. The pertrochanteric external fixator reduced pain, hospital stay, and mechanical complications in comparison with the sliding hip screw. J Bone Joint Surg Am. 2002; 84-A:1488.

14. Clevenland M, Bosworth DM, Thompson FR, Wilson HJ Jr, Ishizuka T. A ten-year analysis of intertrochanteric fractures of the femur. J Bone Joint Surg Am. 1959; 41-A:1399–1408.

15. AO Synthes. The manual of PFNA and PFNA II. Paoli, Switzerland: AO Synthes;2011.

16. Hwang JH, Oh JK, Han SH, Shon WY, Oh CW. Mismatch between PFNa and medullary canal causing difficulty in nailing of the pertrochanteric fractures. Arch Orthop Trauma Surg. 2008; 128:1443–1446.

17. Khang G, Choi K, Kim CS, Yang JS, Bae TS. A study of Korean femoral geometry. Clin Orthop Relat Res. 2003; (406):116–122.

18. Sommers MB, Roth C, Hall H, et al. A laboratory model to evaluate cutout resistance of implants for pertrochanteric fracture fixation. J Orthop Trauma. 2004; 18:361–368.

19. Lee KB, Lee BT. Complications of femoral pertrochanteric fractures treated with proximal femoral nail (PFN). J Korean Fract Soc. 2007; 20:33–39.

20. Boopalan PR, Oh JK, Kim TY, Oh CW, Cho JW, Shon WY. Incidence and radiologic outcome of intraoperative lateral wall fractures in OTA 31A1 and A2 fractures treated with cephalomedullary nailing. J Orthop Trauma. 2012; 26:638–642.

21. Palm H, Jacobsen S, Sonne-Holm S, Gebuhr P. Hip Fracture Study Group. Integrity of the lateral femoral wall in intertrochanteric hip fractures: an important predictor of a reoperation. J Bone Joint Surg Am. 2007; 89:470–475.

22. Hsu CE, Shih CM, Wang CC, Huang KC. Lateral femoral wall thickness. A reliable predictor of post-operative lateral wall fracture in intertrochanteric fractures. Bone Joint J. 2013; 95-B:1134–1138.