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CASE REPORTS

Sponsorship provided by DePuy Synthes

New-Generation Femoral Neck Fixation for the Treatment ofa Nondisplaced Femoral Neck Fracture in an Elderly Patient

Eben A. Carroll, MD

Summary: Femoral neck fractures are challenging fractures to treat.Anatomic fracture reduction drives outcomes in all patient popula-tions. In the elderly with nondisplaced or stable valgus-impactedfracture patterns, success hinges on a construct’s ability to maintainreduction. New-generation femoral neck fixation constructs maydecrease failure rates by providing increased mechanical stability.This case explores the use of a new-generation femoral neck fixationconstruct to stabilize a femoral neck fracture in an elderly patient.

Key Words: femoral neck fracture, femoral neck fixation,elderly, hip fracture

INTRODUCTIONThe management of intracapsular femoral neck fractures in

young and elderly patients presents challenges to the treatingsurgeon. The demanding biomechanical environment of theproximal femur, a tenuous vascular supply, and a lack of periostealfracture response all contribute to making femoral neck fractures atrisk for complications.

For displaced femoral neck fractures in younger populations,complication rates in the literature approach 64% if you combinerates of reoperation, malunion, nonunion, avascular necrosis,

infection, and implant failure.1 These rates of complication aresimilarly high in elderly populations.2,3 For this reason, there isclear consensus that displaced femoral neck fractures in cognitivelyintact elders should undergo arthroplasty.4–6

However, there is controversy as to the ideal treatment ofnondisplaced intracapsular fractures in the elderly.7 Even nondis-placed femoral neck fractures in older cohorts have a 10% reopera-tion rate.8Most cases of failure result from secondary displacementand nonunion due to inadequate implant stability provided by tra-ditional constructs.7 In fact, multiple studies have shown that ratesof reoperation for displaced fractures treated with hemiarthroplastyare lower than reoperation rates of nondisplaced fractures treatedwith internal fixation.9 This is compounded by evidence that pa-tients converted to arthroplasty after failed internal fixation haveinferior outcomes to those undergoing immediate arthroplasty.10

There are, however, benefits to internal fixation in nondisplacedfractures both to health systems andmore importantly to the patient.From the standpoint of direct and indirect costs, traditional implantsused for internal fixation are cheaper than prosthetic options and theoperative time necessary to fix versus replace may be shorter.Moreover, few would argue there is inherent value in maintainingthe native hip joint in patients without pre-existing arthritis.

With the current case, we will examine a patient with a valgusimpacted femoral neck fracture treated with a new generation offemoral neck fixation (NGFNF). Specifically, we will pose but notseek to answer the question, “Can newer-generation implantslessen failure and complications in elderly nondisplaced femoralneck fractures”?

CASE REPORTA79-year-oldman sustained an unwitnessed ground-level fall at

home. Hismedical historywas significant for chronic alcohol abusewith resultant dementia, hypertension, coronary artery disease,history of lacunar cerebrovascular accident, as well as severaldocumented falls at home.

From the Department of Orthopaedic Surgery, Wake Forest UniversitySchool of Medicine, Winston-Salem, NC.

The author is a paid consultant for DePuy Synthes and Globus. He re-ceives royalties from Globus. He is a paid speaker for DePuy Synthes andreceives travel support from the AO Foundation.

Reprints: Eben A. Carroll, MD, Department of Orthopaedic Surgery,Wake Forest University School of Medicine, Medical Center Blvd,Winston-Salem, NC 27157 (e-mail: ecarroll@wakehealth.edu).

The views and opinions expressed in this case report are those of theauthors and do not necessarily reflect the views of the editors of Journalof Orthopaedic Trauma or DePuy Synthes.

Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.

DOI: 10.1097/BOT.0000000000001785

J Orthop Trauma � 2020 www.jorthotrauma.com e1

The patient was found down by emergency medical servicespersonal with a laceration over his eye and chief complaints of left hippain and inability to bearweight. Before this fall, hewalkedwithout anassistive device. Plain radiographs, three-dimensional computedtomography (CT) reconstruction, and an axial CT slice obtained atinitial consultation are shown in Fig. 1. At our institution, elders withfemoral neck fractures that could either be treatedwith internalfixationor arthroplasty, a CT scan is obtained to assure sagittal plane displace-ment and fracture complexity are fully understood.

Based on his imaging, his fracture pattern and displacementoperative fixation were considered. After a lengthy discussion with

the patient’s family, the decision was made to proceed with oper-ative fixation. A NGFNF was chosen to allow for minimally inva-sive insertion while maximizing mechanical fixation and stabilitywhen compared with previous generation implants.11

SURGICAL TECHNIQUEThe patient required a preoperative echocardiogram and cor-

rection of electrolyte abnormalities and was medically cleared onhospital day 2. Spinal anesthesia and a fracture table were used.Care was taken to gently manipulate his left leg to avoiddisimpacting the impacted valgus position of his fracture. Theability to obtain adequate anteroposterior and lateral radiographswas confirmed.

After standard surgical prep and draping, a lateral incision wasmade centered at the level of the mid to distal aspect of the lessertrochanter (Fig. 2). Dissection was taken down to the level of theiliotibial band. The iliotibial band was incised in line with the skinincision. The vastus lateralis can then be elevated from posterior toanterior, or the muscle fibers of the lateralis can be split in line withthe skin incision. We prefer and performed the former.

The guide for the NGFNF used in this case is used to placea guide pin in a center–center position in the femoral head. In theauthors’ opinion, surgeons familiar with sliding hip screw place-ment will find this portion of the technique quite familiar. Onedifference to point out is that placing the pin slightly inferior in thefemoral head prevents placing the second antirotation screw in a toocranial position (Fig. 3).

After confirmation of appropriate pin placement in both thecoronal and sagittal planes, a triple reamer is used to create a pathfor the blade. Insertion in aminimally invasivemanner is facilitatedby the insertion jig (Fig. 4). It is critical at this juncture to assure thatthe small lateral foot print of the plate is centered on the lateralaspect of the shaft (Fig. 5). This needs to be completed beforeplacing the antirotation screw that prevents any further sagittalplane correction. This will be a difference for surgeons accustomedto making rotational corrections of the plate after lag screw inser-tion with the traditional sliding hip screw (SHS). There are cur-rently 2 plate options—1 hole and 2 hole. It is the authors’preference to use the 1-hole plate as it allows for insertion througha smaller incision and is easier to center on the lateral femur. It iscritical to avoid placing the distal aspect of the plate too posterior oranterior to avoid creating a stress riser in the subtrochanteric region.

Finally, the locking plate screw was placed. Final anteroposte-rior and lateral radiographs of the proximal femur demonstratedappropriate fracture reduction and placement of fixation device(Fig. 6). Thewoundwas irrigated and closed in a layered fashion. In

FIGURE 1. A, B, Plain radiographs and a volumerendered CT reconstruction lateral view of the lefthip demonstrate a valgus impacted femoral neckfracture.

FIGURE 2. Intraoperative clinical photograph demonstratesincision needed for FNS insertion. Angled guide wire insertion,blade and plate, and plate screw insertion are all accomplishedthrough this single incision.

Carroll

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the authors’ hands, operative time with this device is comparable orshorter than the time needed for placement of 3 cannulated screws.

The patient was made weight bearing as tolerated postopera-tively. Our postoperative protocol for hip fractures involvesphysical therapy on postoperative day 1, deep venous thromboses(DVT) prophylaxis with aspirin, and outpatient referral to ourosteoporosis clinic. He was discharged on hospital day 5. Hispostoperative course was uncomplicated. He returned to the officeat 3 months. He was ambulating without pain or limp. Radiographsshowed maintenance of reduction with slight shortening of thefracture (Fig. 7).

DISCUSSIONIn the current case, we chose to use a NGFNF to fix a valgus-

impacted femoral neck fracture in an elderly patient. We chose thisimplant because we felt it would potentially lessen failure byproviding increased mechanical stability compared to screws with,in our opinion, simpler insertion than a sliding hip screw construct.

The ideal treatment of valgus impacted or nondisplaced femoralneck fractures is debatable. Failure rates of internal fixation withtraditional implants (cannulated screws or sliding hip screws) are

FIGURE 3. Intraoperative fluoroscopy demonstrates the authors’preferred pin placement in both the coronal and sagittal planes.Note the slightly caudal position of the guidewire from traditionalcenter–center on the anteroposterior view in (A). The guidewire isplaced in the center–center position in the sagittal plane asshown in (B).

FIGURE 4. Insertion handle facilitates plate, blade, shaft, andantirotation screws all through a single lateral incision.

FIGURE 5. A, Shows that the distal aspect of the plate is tooanterior on the femoral shaft. B, Demonstrates correction of thiserror by rotation of the surgeon’s hand in a counterclockwiseposition (for the left hip). Note this must be checked and cor-rected before placement of the antirotation screw.

FIGURE 6. A, B, Anteroposterior (AP) and lateral fluoroscopicimaging show final fracture reduction and implant position.

New-Generation Femoral Neck Fixation

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higher than once believed in this population.7,8 These failures areoften due to loss of mechanical support with postoperative dis-placement leading to nonunion.8 It therefore makes intuitive sensethat fixation constructs, which provide increased stability, maydecrease this failure rate.

The ideal manner of mechanically stabilizing these fractures hasyet to be elucidated.12 Implantswidely available today include fullyand partially threaded cannulated screws and fixed-angle slidinghip screw devices. Sliding hip screw devices have been shown tohave a lower short-term failure rate than cannulated screws.13 How-ever, there is not enough evidence to recommend an optimalmethod of internal fixation regarding long-term outcome.12

Screwsmay be advantageous in terms of reduction. For example,a partially threaded cannulated screw placed at the cranial aspect ofa traditional inverted triangle pattern can compress the cranial neckand lessen varus. At worst, screws do not disrupt a good provisionalreduction or nondisplaced fracture because they exert less ofa rotational force on insertion than sliding hip screws. This wasimportant in the current case because disrupting the impacted andvalgus position of the fracture could have increased failure risk.However, screws are not as effective at preventing varus collapse,retroversion, and combating the shear forces that lead to failure.11

Fixed-angle sliding hip screw devices resist shear and varuscollapse; however, in the authors’ experience, they have a higherpropensity to disrupt an impacted or nondisplaced fracture. This isespecially true in the rotational plane because the sliding screw isadvanced in transcervical or subcapital fracture patterns. Slidinghip screw devices exert a strong rotational force on the head seg-ment, which may cause inadvertent rotational malreduction. Evenin cases where this malreduction is realized and corrected, it isconceivable that irreversible damage to the femoral head bloodsupply may occur. Although the fixed-angle sliding hip screwdevice has been shown to be biomechanically superior,14 thisadvantage has not been realized in clinical studies.12 This may bedue to disruption of a provisional anatomic reduction, which mit-igates the biomechanical advantage. This rotational disruption ofreduction may be one factor that explains the increased rates ofavascular necrosis.15

A new generation of implants is emerging, which may leveragethe mechanical strengths of fixed-angle devices without the short-comings of SHS insertion. The NGFNF used in this case has anarticulated bolt and screw construct, which exerts no rotationalmoment on the head segment during insertion, unlike a sliding hip

screw, and therefore may avoid displacing a nondisplaced orimpacted fracture pattern during implant insertion. Moreover, theinsertion instruments allow this implant to be placedmore efficiently.Finally, the implant is designed to limit more than 1 cm of fracturecompression and may limit the excessive shortening that can occurpostoperatively that leads to worse functional outcomes.16

CONCLUSIONSCurrently, there is controversy as to the ideal treatment of

minimally displaced intracapsular femoral neck fractures in elderlypopulations.7 NGFNF, such as the one used in this case, mayimprove fracture stability when compared with traditional fixationconstructs11 and could decrease the risk of failure in these elderlypatients.

REFERENCES1. Slobogean GP, Sprague SA, Scott T, et al. Complications following youngfemoral neck fractures. Injury. 2015;46:484–491.

2. Frihagen F, Nordsletten L, Madsen JE. Hemiarthroplasty or internal fixa-tion for intracapsular displaced femoral neck fractures: randomized con-trolled trial. BMJ. 2007;335:1251–1254.

3. Parker MJ, Gurusamy K. Internal fixation versus arthroplasty for intra-capsular proximal femoral fractures in adults. Cochrane Database SystRev. 2006:CD001708.

4. Leonardsson O, Sernbo I, Carlsson A, et al. Long-term follow-up ofreplacement compared with internal fixation for displaced femoral neckfractures: results at ten years in a randomized study of 450 patients. J BoneJoint Surg Br. 2010;92:406–412.

5. Blomfeldt R, Törnkvist H, Ponzer S, et al. Comparison of internal fixationwith total hip replacement for displaced femoral neck fractures. Random-ized, controlled trial performed at four years. J Bone Joint Surg Am. 2005;87:1680–1688.

6. Ravikumar KJ, Marsh G. Internal fixation versus hemiarthroplasty versustotal hip arthroplasty for displaced subcapital fractures of femur-13 yearresults of a prospective randomized study. Injury. 2000;31:793–797.

7. Richards JT, Overman AL, O’Hara NN, et al. Internal fixation versusarthroplasty for the treatment of nondisplaced femoral neck fracture inthe elderly: a systematic review and meta-analysis. J Orthop Trauma.2020;34:42–48.

8. Griffin J, Anthony TL, Murphy DK et al. What is the impact of age onreoperation rates for femoral neck fractures treated with internal fixationand hemiarthroplasty? A comparison of hip fracture outcomes in the veryelderly population. J Orthop. 2016;13:33–39.

9. Hui AC, Anderson GH, Choudhry R, et al. Internal fixation or hemiar-throplasty for undisplaced fractures of the femoral neck in octogenarians. JBone Joint Surg Br. 1994;76:891–894.

10. Zielinski SM, Keijsers NL, Praet SFE, et al. Functional outcome aftersuccessful internal fixation versus salvage arthroplasty of patients witha femoral neck fracture. J Orthop Trauma. 2014;28:e273–e280.

FIGURE 7. A, B, Three-month postoperative ante-roposterior (AP) and lateral plain radiographs dem-onstrate slight shortening of the fracture.

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11. Stoffel K, Zderic I, Gras F, et al. Biomechanical evaluation of the femoralneck system in unstable Pauwels III femoral neck fractures: a comparisonwith the dynamic hip screw and cannulated screws. J Orhop Trauma.2017;31:131–137.

12. Hoshino CM, O’Toole RV. Fixed angle devices versus multiple cancellousscrews: what does the evidence tell us? Injury. 2015;46:474–477.

13. Gardner S, Weaver MJ, Jerabek S, et al. Predictors of early failure inyoung patients with displaced femoral neck fractures. J Orthop. 2015;12:75–80.

14. Bonnaire FA, Weber AT. Analysis of fracture gap changes, dynamic andstatic stability of different osteosynthetic procedures in femoral neck.Injury 2002;33(suppl 3):SC24–SC32.

15. Nauth A, Creek AT, Zellar A, et al. Fracture fixation in the operativemanagement of hip fractures (FAITH): an international, multicentre, rand-omised controlled trial. Lancet. 2017;389:1519–1527.

16. Zlowodzki M, Ayeni O, Petrisor BA, et al. Femoral neck shortening afterfracture fixation with multiple cancellous screws: incidence and effect onfunction [published correction appears in J Trauma. 2015;79:704. Ayie-ni, Olufemi [corrected to Ayeni, Olufemi]]. J Trauma. 2008;64:163–169.

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New-Generation Femoral Neck Fixation

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