Effect of End Cap Type on Outcomes in Elderly Intertrochanteric Fractures Treated With PFNA
DOI:
https://doi.org/10.56929/jseaortho-2026-0281Keywords:
intertrochanteric fracture, PFNA, end cap, elderly, fixation, complicationsAbstract
Purpose: Intertrochanteric hip fractures in the elderly are most commonly managed using a proximal femoral nail anti-rotation (PFNA) system, which employs a helical blade secured by either a locked or non-locked end cap. While locked end caps prevent blade migration, they may concentrate stress and increase cut-out risk; non-locked end caps allow controlled dynamization but can permit lateral sliding. This study evaluated the influence of end cap choice on radiographic union and mechanical complications in elderly patients.
Methods: We performed a retrospective cohort analysis of 107 patients aged ≥ 60 years with low-energy intertrochanteric fractures treated with PFNA at Sansai Hospital between January and December 2024. Surgeons selected locked (n = 54) or non-locked (n = 53) end caps based on fracture stability and bone quality. The primary outcome was radiographic union at final follow-up (mean 267.5 ± 50.0 days). Secondary outcomes included screw cut-out, screw cut-through, and lateral blade migration. Fisher’s exact test was used, with p < 0.05 considered significant.
Results: Overall union was achieved in 95.3% of patients, with no significant difference between groups (92.6% vs. 98.1%, p = 0.363). In the locked group, three patients (5.6%) had screw cut-out requiring arthroplasty. In the non-locked group, two patients (3.8%) developed lateral migration requiring implant removal. No central cut-through occurred.
Conclusions: Both end caps types yielded high union rates. Locked end caps carry a higher risk of screw cut-out, whereas non-locked end caps are associated with lateral blade migration. Locked end caps may have more catastrophic failure requiring major revision.
Metrics
References
National Statistical Office, Thailand. Executive Summary: The 2024 Survey of The Older Persons in Thailand [Internet]. 2024. Available from: https://www.nso.go.th/nsoweb/storage/survey_detail/2025/20241209145003_88327.pdf. Accessed Sep 14, 2025.
Wongtriratanachai P, Luevitoonvech S, Songpatanasilp T, et al. Increasing incidence of hip fracture in Chiang Mai, Thailand. J Clin Densitom 2013;16:347-52.
Feger J, Qureshi P, Er A. Proximal femoral nail fixation. Radiopaedia. Available from: https:// radiopaedia.org/articles/proximal-femoral-nail-fixation-1. Accessed Sep 14, 2025.
Huang SG, Chen B, Zhang Y, et al. Comparison of the clinical effectiveness of PFNA, PFLCP, and DHS in treatment of unstable intertrochanteric femoral fracture. Am J Ther 2017;24:e659-66.
Parker MJ, Handoll HH. Gamma and other cephalocondylic intramedullary nails for hip fractures. Cochrane Database Syst Rev 2010;(11):CD000093.
Butler A, Condon F. The effect of time to surgery on functional ability at six weeks in a hip fracture population in Mid-West Ireland. Int J Orthop Trauma Nurs 2017;26:36-42.
Shiga T, Wajima Zi, Ohe Y. Is operative delay associated with increased mortality of hip fracture patients? Systematic review, meta-analysis, and meta-regression. Can J Anaesth 2008;55:146-54.
Simunovic N, Devereaux PJ, Sprague S, et al. Effect of early surgery after hip fracture on motality and complications: systematic review and meta-analysis. CMAJ 2010;182:1609-16.
Al-Ani A, Samuelsson B, Tidermark J, et al. Early operation on patients with a hip fracture improved the ability to return to independent living. A prospective study of 850 patients. J Bone Joint Surg Am 2008;90:1436-42.
Klestil T, Roder C, Stotter C, et al. Impact of timing of surgery in elderly hip fracture patients: a systematic review and meta-analysis. Sci Rep 2018;8:13933.
Kinglam T, Wang CW, Kit MY. An analysis: Risk factors of cut-out following treatment of intertrochanteric hip fractures with proximal femur nail antirotation (PFNA) system. J Orthop Trauma Rehabil. Accessed June 4, 2025.
Liu JJ, Shan LC, Deng BY, et al. Reason and treatment of failure of proximal femoral nail antirotation internal fixation for femoral intertrochanteric fractures of senile patients. Genet Mol Res 2014;13:5949-56.
Li Z, Gao J, Wu X, et al. Risk factors for implant failure of PFNA–II in the treatment of intertrochanteric fractures (AO/OTA 31 A1 and A2). BMC Musculoskelet Disord 2025;26:784;
Koyuncu Ş, Altay T, Kayalı C, et al. Mechanical failures after fixation with proximal femoral nail and risk factors. Clin Interv Aging 2015;10:1959-65.
Synthes. TFNAdvance proximal femoral nailing system, For intramedullary fixation of proximal femoral fratures, Surgical technique. 2021. Available from: https://www.kalteq.com/wp-content/uploads/2024/07/TFN-ADVANCEDTM-Proximal-Femoral-Nailing-System.pdf. Accessed Sep 17, 2025.
Davis TR, Sher JL, Horsman A, et al. Intertrochanteric femoral fractures. Mechanical failure after internal fixation. J Bone Joint Surg Br 1990;72:26-31.
Synthes. DHS/DCS System. Including LCP DHS and DHS Blade, Technique Guide. 2010. Available from: https://pdf4pro.com/cdn/dhs-dcs-system-including-lcp-dhs-27aad7.pdf. Accessed Sep 17, 2025.
Synthes. PFNA Leading the way to optimal stability, Surgical Technique. 2005. Available from: https://www.rch.org.au/uploadedFiles/Main/Content/ortho/PFNA-Proximal_Femoral_Nailing-A_System.pdf. Accessed Sep 17, 2025.
Bhandari M, Chiavaras MM, Parasu N, et al. Radiographic union score for hip substantially improves agreement between surgeons and radiologists. BMC Musculoskelet Disord 2013;14:70.
Frank T, Osterhoff G, Sprague S, et al. The radiographic union score for hip (RUSH) identifies radiographic nonunion of femoral neck fractures. Clin Orthop Relat Res 2016;474:1396-404.
Hoffmann MF, Khoriaty JD, Sietsema DL, et al. Outcome of intramedullary nailing treatment for intertrochanteric femoral fractures. J Orthop Surg Res 2019;14:360.
Siddiqui YS, Khan AQ, Asif N, et al. Modes of failure of proximal femoral nail (PFN) in unstable trochanteric fractures. MOJ Orthop Rheumatol 2019;11:7-16.
Yoon JY, Park S, Kim T, et al. Cut-out risk factor analysis after intramedullary nailing for the treatment of extracapsular fractures of the proximal femur: a retrospective study. BMC Musculoskelet Disord 2022;23:107.
Kellam JF, Meinberg EG. Fracture and dislocation classification compendium-2018. J Orthop Trauma 2018;32 Suppl 1:S1-S170.
Brunner A, Büttler M, Lehmann U, et al. What is the optimal salvage procedure for cut-out after surgical fixation of trochanteric fractures with the PFNA or TFN?: A multicentre study. Injury 2016;47:432-8.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 The Royal College of Orthopaedic Surgeons of Thailand
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
