JOT

JOURNALOF ORTHOPAEDIC

TRAUMA

www.jorthotrauma.com

OFFICIAL JOURNAL OF

Belgian Orthopaedic Trauma Association

Canadian Orthopaedic Trauma Society

Foundation for Orthopedic Trauma

International Society for Fracture Repair

The Japanese Society for Fracture Repair

Orthopaedic Trauma Association

AOTrauma North America

Special Case Report Series

CASE REPORTS

Sponsorship provided by DePuy Synthes

Use of Polymethyl Methacrylate Bone Cement to Augment theSalvaging of Failed Hip Fracture Fixation

Sarah Blumenthal, MD and Samir Mehta, MD

Summary: Cephalomedullary nails are frequently used forfixation of both stable and unstable hip fractures. Despite theirmany proven benefits, complications including fracture collapseand malunion remain a concern. At present, there is no goldstandard technique for revision fixation in these instances. Wepresent here a case of peri-implant failure after cephalomedullarynailing of an OTA/AO 31A2.2 left pertrochanteric hip fracture.The patient was successfully revised by treatment using a prox-imal femoral nailing system with polymethyl methacrylateaugmentation.

Key Words: cephalomedullary nail, pertrochanteric hip fracture,fixation failure, revision fixation, cement augmentation

INTRODUCTIONCephalomedullary nails (CMNs) are a common fixation method

for pertrochanteric hip fractures. Although they may be used forboth stable and unstable fractures, they are not without complica-tions, which include screw cutout, infection, peri-implant fractures,fracture collapse, and device failure.1 These complications may

necessitate early or late return to the operating room and evencomplex revision, often with suboptimal outcomes.

First introduced in the 1990s, CMNs have improved biomechan-ics, decreased bleeding, and allowed for earlier weight bearing,particularly in unstable fracture patterns. With the advent of theintegrated dual screw construct, newermodifications provide optionsfor locked interfragmentary compression and antirotation control.2,3

Yet studies continued to show conflicting data on complications andfailure of instrumentation between varying designs. Helical bladesoffered a novel solution to screw cutout in osteoporotic hip fractures,with supporting biomechanical data.4 Clinical data corroboratedthese findings. A meta-analysis of 10 randomized controlled trials(RCTs) showed reduced rates of cutout in helical blade systemscompared with conventional lag screw designs.5 This differencewas independent of tip–apex distance (TAD), which has been dem-onstrated previously to predict pertrochanteric hip fracture fixationfailure when the TAD is less than 25 mm in sliding hip screws.6

Several studies have demonstrated worse outcomes when sub-sidence of fixation constructs leads to femoral shortening.7 Given over-all low rates of failure after CMNs, there is no gold standard techniquefor revision options in pertrochanteric fracture nonunion or malunion.In a retrospective evaluation of 20 patients who experienced fatiguefailure after CMNs, immediate postoperative radiographs revealed thata significant proportion of these fractureswerefixed in varus. The samestudy demonstrated that inadequate reductions resulted in earlier nailfailure, with a mean time to failure of 1.1 years. Amulticenter study of1360 CMNs performed over a 16-year time frame revealed a 1.47%incidence ofmechanical failure,whichwas similar to previous studies.8

Methods of revision included revision nailing, proximal femoral lock-ing plate, long-stem or hydroxyapatite-coated diaphyseal fit modulararthroplasty, or proximal femoral endoprosthesis.

Although the introduction of helical blades has been reported todecrease the incidence of cephalic screw cutout from 12% to 3.6%, thepoor quality of the osteoporotic bone may still complicate optimalfracture fixation.9 The proximal femoral nail antirotation (PFNA;DePuy Synthes, West Chester, PA) device was developed and

From the Division of Orthopaedic Trauma and Fracture Care, Departmentof Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA.

S. Mehta—Consulting: Depuy Synthes, Smith & Nephew; Grants: DOD,NIH, PCORI; Board Membership: AOA, OTA/AO Foundation. The re-maining author reports no conflict of interest.

Reprints: Samir Mehta, MD, Division of Orthopaedic Trauma and Frac-ture Care, Department of Orthopaedic Surgery, University of Pennsylva-nia, 3737 Market St, Philadelphia, PA 19104 (e-mail: samir.mehta@pennmedicine.upenn.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.0000000000001862

J Orthop Trauma � 2020 www.jorthotrauma.com e1

introduced in 2003; it combined a helical blade adaptation with theoption for application of bone cement through perforations in the bladeto augment the mechanical strength of the device.10,11 A prospective,multicenter RCT compared outcomes of patients treatedwith andwith-out cement augmentation and found fewermechanical complications inthe nonaugmentation group, although these did not reach clinical sig-nificance possibly because of overall low rates of catastrophic failure.12

Cadaveric studies have also validated improved cut-out resistance withcement augmentation.11 The Trochanteric Fixation Nail-Advanced(TFNA) Proximal Femoral Nailing System (DePuy Synthes) wasbrought to the market in 2015 to offer either blade or screw fixationof the femoral head with a modified alloy, designed to improve fatigueresistance and strength.13 It allowed for cement augmentation based onthe same principles, with augmentation integrated into the design in2017. We describe here the use of a TFNA with polymethyl methac-rylate (PMMA) augmentation as a salvage option for failed cephalo-medullary fixation of a pertrochanteric hip fracture.

PATIENT CASEA 79-year-old male community ambulator who required

a walker for ambulation sustained a ground-level mechanical fallat home with immediate pain in the left hip and inability toambulate. His medical history was significant for coronary arterydisease status after double coronary artery bypass graft 2 yearsbefore, also mitral valve replacement for mitral regurgitation 2years before, hypertension, paroxysmal atrial fibrillation on dailywarfarin, and chronotropic incompetence with implanted looprecorder. He also had a history of contralateral knee periprostheticjoint infection, for which he completed appropriate treatment.

Radiographs demonstrated an OTA/AO 31A2.2 left pertrochan-teric hip fracture (Fig. 1).14 He had no other injuries. He was admit-ted by the geriatric multidisciplinary hip fracture protocol,medically cleared by the hospitalist, and consented for surgery.

Index SurgeryAt the time of his index surgery, a long intramedullary nail

(Intertan; Smith Nephew, Memphis, TN) was used for fracturefixation. Under general anesthesia, the patient was positionedsupine on a radiolucent flat-top table. Reduction was achievedusing distal femoral traction by a 5/64 inch Kirschner (K) wire,internal rotation and adduction of the limb. Using standardtechniques, the starting point on the tip of the greater trochanterwas identified and verifiedwith fluoroscopy. The standard 17.0mmentry reamer was used to open the proximal femoral canal. A 103420 mm nail was advanced. The standard Intertan technique wasused to place the lag screw and the second proximal interdigitatingscrew subsequently. Two distal interlocking bolts were placedusing the standard technique. Live fluoroscopy demonstrated thatthe cephalomedullary screws were extra-articular. There were nointraoperative complications with the procedure, and the patienthad a routine postoperative course with immediate weight-bearing.

Postoperative radiographs demonstrated a 15 degree flexiondeformity with the proximal femur in 121 degrees of varusmalposition, as well as residual comminution and fracture gappingvisible medially (Fig. 2). TAD was 19.0 mm. The on-call surgeonfelt that the axial and anteroposterior (AP) alignment were in anacceptable range for healing and that the 2 screw integrated

FIGURE 1. AP radiograph of the pelvis demonstrating OTA/AO31A2.2 left pertrochanteric hip fracture.

FIGURE 2. AP (A) and lateral (B) postoperative ra-diographs after initial fracture fixation with cepha-lomedullary device revealing medial comminution.

Blumenthal and Mehta

e2 www.jorthotrauma.com Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.

construct would provide sufficient stability. The patient was dis-charged to skilled nursing facility for rehabilitation on the thirdpostoperative day.

ComplicationApproximately 6 months after surgery, the patient developed

progressive left groin pain aggravated by activity. He presented tothe emergency department because of uncontrolled pain. At thistime, there was radiographic migration of the construct superiorlywith worsening of the varus deformity, nowmeasuring 117 degreeswith 8mm of proximal screwmigration (Fig. 3). Computed tomog-raphy verified hypertrophic malunion, worsening of the varusdeformity, and lag screw abutting superior cortex of the femoralhead (Fig. 4). After lengthy conversation with the patient and fam-ily regarding operative and nonoperative treatment, the patientopted to proceed with implant removal and revision intramedullarynailing.

The patient underwent revision fixation with TFNA withPMMA augmentation. Rationale for augmentation included (1)revision surgery, (2) large cavitary defect in the femoral headresulting from migration around the previous implants, and (3)posteromedial comminution.

SURGICAL TECHNIQUEThe patient was brought to the operating room and induced

under general anesthesia. He was positioned on a flat top

radiolucent table, and the left leg was prepped and draped ina standard fashion. Antibiotics were administered before incision.

Attention was first directed toward removal of the implants.Under fluoroscopy, standard nail removal techniques were used tosuccessfully remove the indwelling implants. Of note, when thedirect lateral surgical approach15 to the proximal femur incorporat-ing previous incisions was performed, a seroma was encountered.Cultureswere obtained and sent for standard gram stain and culture.

After indwelling implant removal, a small diameter K wire wasplaced in the distal femur, a sterile Kirschner traction bow applied,and a sterile rope was attached over a custom-made pipe benderattached to the operative table with 15 pounds of skeletal tractionapplied. Once skeletal traction was applied, there was immediateimprovement in the overall length and varus malalignment of theproximal femur. A portion of the anterior fracture callus wasremoved with an osteotome and rongeur.With debridement of thenonunited heterotopic bone, the fracture site was noted to allowfor sufficient distraction for a Cobb elevator to be inserted throughthe previously made incision. The Cobb elevator was levered tohelp further distract the fracture site, at which point traction wasnoted to adequately maintain the overall alignment and length.Once the alignment was improved on the both the AP and axialviews, attention was turned in creating a new stable proximalfemur (Fig. 5).

A guide pin was inserted through the incision to a more medialstarting point on the greater trochanter than previously used. ACobb elevator was placed in the previous starting point to prevent

FIGURE 3. Radiographs 6 monthsafter index surgery demonstratingpersistent varus deformity on the APhip (A) and flexion malunion on thelateral hip radiographs (B).

FIGURE 4. Axial (A) and coronal (B) cuts on thecomputed tomography scan 6 months after indexsurgery demonstrating screw migration in the fem-oral head with impending failure. Screw migrationresults in the bone void in the femoral head withincreasing instability.

Salvaging of Failed Hip Fracture Fixation

Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved. www.jorthotrauma.com e3

the nail from falling into this more lateral hole. The guidewire wasadvanced into the proximal femur, with AP and lateral fluoroscopicviews showing it to be in the appropriate position. The 15 mmopening channel reamer was used. A ball-tipped guidewire was

advanced past the traction pin and inserted down to the level of thephyseal scar. Sequential reaming was performed with standardflexible medullary reamers up to 13 mm.

A 12 3 440 mm TFNA (Depuy Synthes) was then insertedover the ball-tipped guidewire. The guidewire was removed.Using the external targeting guide, the cephalomedullary guide-wire was placed into the femoral head slightly posterior and infe-rior to avoid the area of previous screw cut out. Once the wire wasin place, the length was measured, and the fenestrated helicalblade was placed over the wire. Fluoroscopic imaging verifiedthe position of the helical blade, which was then locked into placewith the set screw.

Cement augmentation was then performed. Using the radi-opaque dye through the jig, the head was confirmed to be intactwithout extrusion of dye into the joint. Sixmilliliters of TraumacemV 1 PMMA cement (Depuy Synthes) was injected through thehelical blade into the femoral head. Once the cement had hardened,2 screws were placed distally using the standard technique. Stan-dard wound closure was performed.

The patient was allowed to weight bear with a walker immedi-ately after surgery. He required postoperative blood transfusionbecause of acute blood loss anemia and was discharged to a skillednursing facility on postoperative day 6. At 1 year, he was walkingwith assist device (baseline) and radiographically healed withoutevidence of failure (Fig. 6).

DISCUSSIONMalunion or failure of fixation after cephalomedullary nailing

are challenging complications in geriatric hip fractures, requiringcomplex revision surgeries without a gold standard technique.The revision implant and technique may be chosen based onmultiple factors, including patient characteristics such as pre-operative function as well as fracture pattern and bone quality.Poor bone quality has a higher risk for catastrophic failure afterfixation.16

PMMA cement augmentation emerged as a viable treatmentoption in select patients because of the newer design of implantsystems that allow injection through fenestrations in the helicalblade inserted in the femoral head. The primary concern withcement augmentation is the possibility of extravasation into thejoint, which has not been born out in the literature. In a prospectivemulticenter study of 59 patients treated with augmented PFNA,only 1 perforation of the K wire into the joint was observedintraoperatively and was detected by injection of the contrastmedium. In cases such as these, cement augmentation is notperformed.17 This risk can be mitigated further with caution whenplacing the K wire to prevent perforation of the femoral head. Ifcement is noted to extravasate into the hip joint despite appropriateprecautions, aggressive irrigation through the cannulation may beconsidered. If unsuccessful, an open or arthroscopic irrigation anddebridement of the hip joint should be performed. Biodegradablealternatives such as calcium phosphate or calcium sulfate may alsobe used to minimize this concern.

Overall, there is increasing evidence from cadaveric andbiomechanical studies that cement augmentation improves themechanical properties of fixation in the osteoporotic bone.16,18

These data seem to be clinically reproducible. For instance, ina RCT of 105 patients allocated to augmentation and 118 to non-augmentation, 6 patients in the nonaugmentation group required

FIGURE 5. Intraoperative fluoroscopic images showing theproximal femur after implant removal (A) (AP view) and callusdebridement (B) (lateral view). After intramedullary nail wasplaced, the helical blade was introduced over the guidewire andlocation was verified [C (AP) and D (lateral)]. Dye was injectedwith no extravasation into the joint noted (E) (AP), and PMMAcement was injected to fill the remaining space [F (AP) and G(lateral)].

Blumenthal and Mehta

e4 www.jorthotrauma.com Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.

revision because of mechanical failure or implant migration com-pared with zero in the augmentation group.12

The final definitive option for failed cephalomedullarynailing remains hip arthroplasty. However, these patients areat a substantially increased risk for complications includinginfection, dislocation, and periprosthetic fractures. Medicaredata on 56,522 patients who underwent hip arthroplasty between2002 and 2015 indicated that revision rates from CMN toarthroplasty are increasing, doubling between 2002–2005 and2012–2015 periods. These patients have a 125% increased riskof infection, 379% increased risk of revision for infection, and321% increased risk of revision for dislocation. These proce-dures also have longer operating times and increased bloodloss.19 Thus, although some evidence supports arthroplasty assalvage for failed hip fracture fixation after CMN, most reportedcases of revision of PFNA or TFNA involve helical bladeexchange with or without cement augmentation, rather thancomplete implant removal.20 As described here, exchange nail-ing, rereduction, and cement augmentation is part of the treat-ment algorithm in revision CMN fixation of failedpertrochanteric hip fractures.

CONCLUSIONSThe optimal treatment for failed CMN of pertrochanteric hip

fractures remains debatable. Surgical decision making must betailored to each individual patient’s physiological needs and frac-ture pattern, accounting for osteoporotic bone and bone voids dueto device migration. PMMA cement augmentation has demon-strated promising results in both cadaveric and clinical studieswhen used to reinforce the mechanical properties of cephalicimplant fixation. Although more studies are needed on its use inboth primary and revision CMN, current research and case reportssuggest it is a viable option in preventing varus collapse and peri-implant complications in osteoporotic hip fractures.

REFERENCES1. Erez O, Dougherty PJ. Early complications associated with cephalomedul-lary nail for intertrochanteric hip fractures. J Trauma Acute Care Surg.2012;72:E101–E105.

2. Serrano R, Blair JA, Watson DT, et al. Cephalomedullary nail fixation ofintertrochanteric femur fractures: are two proximal screws better than one?J Orthop Trauma. 2017;31:577–582.

3. Nüchtern JV, Ruecker AH, Sellenschloh K, et al. Malpositioning of thelag-screws by 1- or 2-screw nailing systems for pertrochanteric femoralfractures: a biomechanical comparison of gamma 3 and intertan. J OrthopTrauma. 2014;28:276–282.

4. Nikoloski AN, Osbrough AL, Yates PJ. Should the tip apex distance(TAD) rule be modified for the proximal nail antirotation (PFNA)? Aretrospective study. J Orthop Surg Res. 2013;17:35.

5. Li S, Chang S, Niu W, et al. Comparison of tip apex distance and cut-outcomplications between helical blades and lag screws in intertrochantericfractures among the elderly: a meta-analysis. J Orthop Sci. 2015;20:1062–1069.

6. Baumgaertner MR, Curtin SL, Lindskog DM, et al. The value of the tip-apex distance in predicting failure of fixation of peritrochanteric fracturesof the hip. J Bone Joint Surg Am. 1995;77:1058–1064.

7. Zlowodzki M, Brink O, Switzer J, et al. The effect of shortening and varuscollapse of the femoral neck on function after fixation of intracapsularfractures of the hip. A multi-centre cohort study. J Bone Joint Surg Br.2008;90:1487–1494.

8. Tucker A, Warnock M, McDonald S, et al. Fatigue failure of the cepha-lomedullary nail: revision options, outcomes and review of the literature.Eur J Orthop Surg Traumatol. 2018;28:511–520.

9. Mereddy P, Kamath S, Ramakrishnan M, et al. The AO/ASIF prox-imal femoral nail antirotation (PFNA): a new design for the treatmentof unstable proximal femoral fractures. Injury. 2009;40:428–432.

10. Li M, Wu L, Liu Y, et al. Clinical evaluation of the Asian proximalfemur intramedullary nail antirotation system (PFNA-II) for treat-ment of intertrochanteric fractures. J Orthop Surg Res. 2014;9:112.

11. Sermon A, Boner V, Boger A, et al. Potential of polymethylmethacrylatecement-augmented helical proximal femoral nail antirotation blades toimprove implant stability—a biomechanical investigation in human cadav-eric femoral heads. J Trauma. 2012;72:E54–E59.

12. Kammerlander C, Hem ES, Klopfer T, et al. Cement augmentation of theProximal Femoral Nail Antirotation (PFNA)—a multicentre randomizedcontrolled trial. Injury. 2018;49:1436–1444.

13. DePuy Synthes. TFN-advanced proximal femoral nailing system valueanalysis brief. 2016. Available at: http://synthes.vo.llnwd.net/o16/LLNWMB8/INT%20Mobile/Synthes%20International/Product%20Support%20MatMater/legacy_Synthes_PDF/DSEM-TRM-0515-0375-1_LR.pdf. Accessed January 24, 2020.

14. Marsh JL, Slongo TF, Broderick JS, et al. Fracture and dislocation clas-sification compendium—2007: Orthopaedic Trauma Association classifi-cation, database and outcomes committee. J Orthop Trauma. 2007;21(suppl 10):S1–S133.

15. Hardinge K. The direct lateral approach to the hip. J Bone Joint Surg Br.1982;64:17–19.

FIGURE 6. AP (A) and lateral (B) radiographs of theleft hip 3 months after revision fixation with cementaugmentation revealing stable fixation and no lossof reduction.

Salvaging of Failed Hip Fracture Fixation

Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved. www.jorthotrauma.com e5

16. Erhart S, Kammerlander C, El-Attal R, et al. Is augmentation a pos-sible salvage procedure after lateral migration of the proximal femurnail antirotation? Arch Orthop Trauma Surg. 2012;132:1577–1581.

17. Kammerlander C, Gebhard F, Meier C, et al. Standardised cementaugmentation of the PFNA using a perforated blade: a new techniqueand preliminary clinical results. A prospective multicentre trial. Injury.2011;42:1484–1490.

18. Fensky F, Nüchtern JV, Kolb JP, et al. Cement augmentation of theproximal femoral nail antirotation for the treatment of osteoporotic per-trochanteric fractures—a biomechanical cadaver study. Injury. 2013;44:802–807.

19. Smith A, Denehy K, Ong KL, et al. Total hip arthroplasty following failedintertrochanteric hip fracture fixation treated with a cephalomedullary nail.Bone Joint J. 2019;101:91–96.

20. Brunner A, Büttler M, Lehmann U, et al. What is the optimal salvageprocedure for cut-out after surgical fixation of trochanteric fractureswith the PFNA or TFN? A multicentre study. Injury. 2016;47:432–438.

Read the rest of the JOT Case Reports online on www.jorthotrauma.com. It’s the Grand Rounds series from the Jour-nal of Orthopaedic Trauma, the official journal of the Ortho-paedic Trauma Association.

Blumenthal and Mehta

e6 www.jorthotrauma.com Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.