n Feature Article

abstract

Comparing Entry Points for Antegrade Nailing of Femoral Shaft FracturesUjash sheth, MD; Chetan Gohal, BhsC; jaskarnDip Chahal, MD, MsC, FrCsC; aaron naUth, MD, MsC, FrCsC; tiM Dwyer, MBBs, FrCsC

The use of intramedullary (IM) nail-ing is currently the gold standard treatment for the vast majority of

femoral shaft fractures.1-3 Despite major advances in the design and engineering of these devices, there remains significant

debate regarding the ideal entry point for antegrade nailing.4,5 Kuntscher’s original IM nail was straight and introduced in antegrade fashion through the tip of the greater trochanter (GT) to minimize the risk of intracapsular infections, osteone-

crosis of the femoral head, and iatrogenic femoral neck fractures.6,7 However, be-cause the tip of the GT is not colinear with the anatomic axis of the medullary canal, the insertion of a straight nail was reported to occasionally result in varus malreduc-tion of the proximal fracture fragment, ec-centric reaming of the medial cortex, and fracture comminution.8 As a result, Han-sen and Winquist9 recommended using an entry point more medial to the GT at the junction of the femoral neck and the GT. At the same time, McMaster10 introduced the piriformis fossa (PF) entry, which is colinear with the medullary canal, as the

The optimal entry point for antegrade intramedullary nailing of femoral shaft fractures remains controversial. The purpose of this systematic review was to determine whether there is a difference in operative parameters, healing, and functional outcome when comparing the greater trochanter (GT) and pirifor-mis fossa (PF) entry points. A systematic search of multiple databases and 3 major orthopedic meetings (American Academy of Orthopaedic Surgeons, Canadian Orthopaedic Association, and Orthopaedic Trauma Association) was conducted. Four studies (570 patients) met the inclusion criteria. Mean patient age was 34.5 years, and 60.4% were male. The GT entry point was associated with significantly shorter operative (mean difference [MD], -20.05 minutes [95% confidence interval (CI), -23.09 to -17.02]; P<.00001) and fluoroscopy times (MD, -24.55 seconds [95% CI, -43.23 to -5.86]; P=.01). There was no significant difference in nonunion (risk ratio [RR], 0.74 [95% CI, 0.35 to 1.58]; P=.44) and delayed union rates (RR, 0.94 [95% CI, 0.41 to 2.14]; P=.88) between the 2 entry points. Heterogeneity in outcome mea-sures reported prevented pooled analysis of functional outcomes. This review supports the use of the GT entry point during antegrade nailing of femoral shaft fractures over the PF entry point, with regard to shorter operative and fluoroscopy times. Healing and complication rates were not related to the entry point. Further study is required to determine the effect of each entry point on the surrounding soft tissue structures and ultimately its impact on postoperative function. [Orthopedics. 2016; 39(1):e43-e50.]

The authors are from the Division of Ortho-paedic Surgery (US, CG, JC, AN, TD), University of Toronto; the Division of Orthopaedic Surgery (US, JC), Toronto Western Hospital; the Division of Orthopaedic Surgery (AN), St Michael’s Hospi-tal; and the Division of Orthopaedic Surgery (TD), Mount Sinai Hospital, Toronto, Ontario, Canada.

Dr Sheth, Mr Gohal, Dr Chahal, and Mr Dw-yer have no relevant financial relationships to dis-close. Dr Nauth receives grants from Synthes and Stryker and nonfinancial support from Stryker.

The authors thank Joshua Hwang, BSc, for his assistance with Korean-English translation.

Correspondence should be addressed to: Ujash Sheth, MD, Division of Orthopaedic Sur-gery, Toronto Western Hospital, 399 Bathurst St, 1 E 447, Toronto, Ontario M5T 2S8, Canada (usheth@qmed.ca).

Received: January 8, 2015; Accepted: May 18, 2015.

doi: 10.3928/01477447-20151218-09

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entry point for antegrade nailing. In the following years, the PF became the start-ing point of choice, due to its favorable biomechanical results.11-13

The debate surrounding the optimal en-try point was revived with the advent of the IM nail featuring a proximal valgus bend. These nails were specifically designed to address the pitfalls associated with insert-ing a straight nail through the GT.4,7 Ricci et al14 were the first to directly compare the GT and PF entry points during ante-grade nailing of femoral shaft fractures.15 Results from their study demonstrated no difference in union rate and complications between the 2 entry points.14 However, they reported significantly shorter opera-tive and fluoroscopy times with the GT en-try point.14 Furthermore, other investiga-tors have advocated the use of GT entry in obese patients, citing increased ease of use in that patient population.16 Since the study

by Ricci et al,14 there have been a number of randomized, controlled trials (RCTs) and cohort studies comparing the efficacy of the 2 entry points on various patient- and procedure-related outcomes.17-20 To the current authors’ knowledge, there has been no systematic review of the literature on optimal entry point during antegrade nailing of femoral shaft fractures.

The primary objective of the current systematic review was to compare the op-erative and fluoroscopic time required for IM nail fixation of femoral shaft fractures using the GT vs the PF entry point. A sec-ondary objective was to determine wheth-er there were any differences in complica-tions (nonunion and delayed union) and functional outcomes between the 2 entry points.

Materials and MethodsEligibility Criteria

The authors identified all RCTs, pro-spective cohort studies (PCSs), and ret-rospective cohort studies (RCSs) that compared GT and PF entry points for an-tegrade IM nail fixation of femoral shaft

fractures in adults. Case series, reviews, and technique and basic science articles that did not report patient-specific data were excluded. There were no language restrictions.

Literature SearchTo identify eligible studies for inclu-

sion, a systematic search of the electronic databases Medline, Embase, PubMed, Cochrane Central Register of Controlled Trials, and clinicaltrials.gov (for ongo-ing registered RCTs) was performed in-dependently by 2 authors (U.S., C.G.). The search was conducted during the week of October 6, 2014, and articles were retrieved from database inception to the search date. Complete Embase and Medline search strategies can be found in Table 1 and Table 2, respectively. Titles of podium and poster presentations in programs of 3 major orthopedic meet-ings (American Academy of Orthopaedic Surgeons, Canadian Orthopaedic Asso-ciation, and Orthopaedic Trauma Associa-tion) from 2011 to 2013 were reviewed for any relevant unpublished studies. Addi-tional studies were detected by searching the bibliographies of eligible studies. The “related articles” feature of PubMed was used to identify similar relevant articles.

Study SelectionArticle titles and abstracts were re-

viewed independently by 2 authors (U.S., C.G.) to determine whether they met in-clusion criteria. If any ambiguity was en-countered, the study was included until full-text review could be performed. The 2 independent reviewers assessed each full-text article for eligibility. Any dis-agreements were discussed between the reviewers and, if required, a third reviewer (J.C.) until consensus was reached.

Data ExtractionData were abstracted by 2 independent

reviewers (U.S., C.G.) into a standardized collection form using Microsoft Excel 2013 (Microsoft, Redmond, Washington).

Table 1

Complete Search Strategy for Medline

Step Search TermNo. of Results

1 exp femoral frac-tures

30,587

2 (femoral adj frac-ture).mp

1644

3 1 or 2 30,902

4 fracture fixation.mp or exp fracture

fixation

48,373

5 exp fracture fixation, intramedullary

7375

6 intramedullary.mp 14,914

7 5 or 6 14,914

8 nail*.mp 31,568

9 6 and 8 6822

10 4 or 7 or 9 55,018

11 trochanter.mp 3677

12 piriformis.mp 568

13 11 or 12 4195

14 3 and 10 and 13 294

Table 2

Complete Search Strategy for Embase

Step Search TermNo. of Results

1 exp femur fractures 26,161

2 (femoral adj2 frac-ture).mp

5708

3 1 or 2 27,087

4 exp intramedullary nailing or exp intra-

medullary nail

12,027

5 exp fracture fixation 64,343

6 4 or 5 65,079

7 exp greater trochan-ter or trochanter.mp

4831

8 piriformis.mp 877

9 7 or 8 5617

10 3 and 6 and 9 359

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Data collected included general study information (author, year of publication, study design, sample size, level of evi-dence), demographic data (mean or me-dian age, sex), IM nail entry point (GT vs PF), IM nail characteristics (manufactur-er), patient positioning (supine or lateral), follow-up data (mean duration, rate), and outcome measures used.

Methodological Quality AssessmentThe quality of eligible studies was as-

sessed independently by 2 authors (U.S., C.G.). The checklist to evaluate a report of a nonpharmacological trial (CLEAR-NPT) was used to assess the quality of RCTs.21 The CLEAR-NPT is a validated checklist used to assess the adequacy of 10 key elements of an RCT.21 The Newcastle-Ottawa Scale (NOS) was used to assess quality of the nonrandomized studies.22 The NOS uses a star system (0 to 9) to evaluate nonrandomized studies on 3 domains: selection, comparability, and outcome/exposure.22 Higher scores on the NOS represent higher study qual-ity. A consensus agreement was achieved between reviewers.

Statistical Analysis Data were pooled across studies; the

weighted mean difference (MD) was calculated for continuous outcomes, and the risk ratio (RR) was calculated for binary outcomes. Point estimates for all outcomes were calculated with their cor-responding 95% confidence intervals (CIs). All tests of significance (2-tailed) were performed with an α value of 0.05. In situations where studies only reported a median and interquartile range (IQR), es-tablished statistical methods were used to obtain converted mean and SD values to allow for pooling of data across studies.23

A random-effects model was used to account for any heterogeneity that may have been introduced due to the variation in the patient population, IM nail design, and operative technique between the stud-ies. The I2 statistic was used to quantify

heterogeneity, and the Cochran chi-square test of homogeneity was used to test for significance (ie, Q test, P<.10).24 An I2 statistic value of greater than 75% was considered high.24 The authors could not assess for publication bias because the number of eligible studies was too small.

A sensitivity analysis was planned to test the robustness of the pooled results by sequential removal of studies one by one. Subgroup analyses that were planned a priori included analyzing the primary out-comes (operative and fluoroscopy time) based on study randomization.

resultsGeneral Study Characteristics

The search resulted in 4 studies14,17-19 that met the eligibility criteria, providing a total of 570 patients for analysis (Fig-ure 1). Included were 2 level I RCTs,17,18 1 level II PCS,14 and 1 level III RCS.19 All of the studies were published in peer- reviewed journals. Of the 4 studies, 3 were

written in English14,17,18 and 1 required translation19 (Korean to English) by a bi-lingual Korean-English medical student. Mean age of participants across all eli-gible studies was 34.5 years. Mean clini-cal follow-up across the 4 studies ranged from 10 to 48 months. Data pertaining to sex were available for 3 studies,14,18,19 and 278 (60.4%) of the 460 patients were male. Patients were placed supine for an-tegrade IM nailing in all of the eligible studies.14,17-19 Information on body mass index (BMI) was available for 3 of the 4 included studies.14,17,19 The frequency-weighted mean BMI across these studies was 25.0 kg/m2 and 24.6 kg/m2 in the GT-entry and PF-entry groups, respectively. Table 3 depicts the baseline characteris-tics of all eligible studies.

Fracture TypeAll of the eligible studies14,17-19 com-

prised adults with isolated femoral shaft fractures (defined by the Orthopaedic

Figure 1: Flow diagram summarizing the search strategy and screening and selection process.

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Trauma Association [OTA] classification system25 as 32A, B, or C). Ricci et al14 included patients with sub-trochanteric fractures (OTA 31-A3) in their eligibility criteria; however, the final study population only in-cluded patients with femo-ral shaft fractures (OTA 32-A/B/C). A breakdown of fracture type based on OTA classification was provided for 3 of the 4 studies.14,17,19 These results are summa-rized in Table 4.

Lateral Bend of Greater Trochanter Entry Nail

In 2 of the 4 studies, the TRIGEN trochanteric an-tegrade nail (TAN) (Smith & Nephew, Memphis, Ten-nessee) that incorporates a 4° proximal valgus bend was used. In another study, the antegrade femoral nail (AFN) (Synthes, Solothurn, Switzerland), which has a 6° proximal valgus bend, was used. The fourth study used a Sirus femoral nail (Zimmer, Warsaw, Indiana), and the degree of proximal lateral bend was not stated in the manuscript; however, the manufacturer’s product guide describes a 4° bend.

Study QualityA summary of the meth-

odological quality assess-ment of included studies using the CLEAR-NPT and NOS is provided in Ta-ble 5 and Table 6, respec-tively. In general, both of the RCTs were of moder-ate methodological quality. One study did not provide

Tabl

e 3

Bas

elin

e C

hara

cter

isti

cs o

f Elig

ible

Stu

die

sM

ean

BMI,

kg/m

2

Stud

ySt

udy

Des

ign

Incl

usio

n C

rite

ria

GT-

Entr

y IM

Nai

lPF

-Ent

ry

IM N

ail

Ope

rati

ve

Pati

ent

Posi

tion

GT-

Entr

y G

roup

PF-E

ntry

G

roup

Sam

ple

Size

(%

Mal

e)

Mea

n A

ge,

yFo

llow

-up

Rat

e

Mea

n Fo

llow

-up,

m

oO

utco

me

Mea

sure

s

Ric

ci e

t a

l14Le

vel I

I, PC

SFe

mor

al s

haft

or s

ubtr

o-ch

ante

ric

frac

ture

a

Trig

en T

AN

N

ail (

Smith

&

Nep

hew

, M

emph

is, T

en-

ness

ee)

Trig

en F

AN

N

ail

Supi

ne24

2491

(59.

3)28

.685

.7%

10O

pera

tive

and

fluor

osco

py ti

me,

un

ion

time,

frac

ture

al

ignm

ent,

LEM

Stan

nard

e

t al17

Leve

l I,

RC

TIs

olat

ed

fem

oral

sha

ft fr

actu

res

Trig

en T

AN

N

ail

Trig

en F

AN

N

ail

Supi

ne28

.127

.811

0 (N

R)

3481

%16

Ope

rativ

e an

d flu

oros

copy

tim

e, in

-ci

sion

leng

th, b

lood

lo

ss, W

OM

AC

, VA

S,

unio

n tim

e, m

uscl

e st

reng

th, f

unct

iona

l te

stin

g (c

hair

sta

nd

test

, tim

ed u

p an

d go

test

)

Moe

in e

t a

l18Le

vel I

, R

CT

Isol

ated

fe

mor

al s

haft

frac

ture

s

Ant

egra

de

Fem

oral

Nai

l (S

ynth

es,

Solo

thur

n,

Switz

erla

nd)

Unr

eam

ed

Fem

oral

Nai

l (S

ynth

es)

Supi

neN

RN

R19

(94.

7)28

.990

.5%

48V

AS,

gai

t ana

lysi

s,

mus

cle

stre

ngth

, EM

G, M

RI

Ha

et

al19

Leve

l III

, RC

SIs

olat

ed

fem

oral

sha

ft fr

actu

res

Siru

s Fe

mor

al

Nai

l (Z

imm

er,

Cow

pens

, So

uth

Car

olin

a)

M/D

N

Fem

oral

Nai

l (Z

imm

er,

War

saw

, In

dian

a)

Supi

ne24

.323

.735

0 (5

8.9)

36.4

81%

24O

pera

tive

and

fluo-

rosc

opy

time,

blo

od

loss

, uni

on ti

me,

H

HS,

com

plic

atio

ns

(LLD

, non

unio

n,

dela

yed

unio

n,

iatr

ogen

ic fr

actu

re,

brok

en s

crew

)

Abb

revi

atio

ns:

BM

I, b

ody

mas

s in

dex;

EM

G, e

lect

rom

yogr

aphy

; FA

N, f

emor

al a

nteg

rade

nai

l; G

T, g

reat

er tr

ocha

nter

; H

HS,

Har

ris

Hip

Sco

re;

IM, i

ntra

med

ulla

ry;

LE

M, l

ower

ext

rem

ity

mea

sure

; L

LD

, lim

b-le

ngth

dis

crep

ancy

; M

RI,

mag

neti

c re

sona

nce

imag

ing;

NR

, not

rep

orte

d; P

CS,

pro

spec

tive

coh

ort s

tudy

; P

F, p

irif

orm

is fo

ssa;

RC

S, r

etro

spec

tive

coh

ort s

tudy

; R

CT,

ra

ndom

ized

, con

trol

led

tria

l; T

AN

, tro

chan

teri

c an

tegr

ade

nail

; VA

S, v

isua

l ana

log

scal

e; W

OM

AC

, Wes

tern

Ont

ario

and

McM

aste

r U

nive

rsit

ies

Ost

eoar

thri

tis

Inde

x.

a No

pati

ents

wit

h su

btro

chan

teri

c fr

actu

res

wer

e pa

rt o

f the

stu

dy.

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enough information to determine whether generation of allocation sequence and sur-geon experience was adequate.18 The oth-er study failed to use the intention-to-treat principle for analysis.17 The nonrandom-ized studies14,19 had study populations (within studies) that were well matched on important demographic and prognostic variables (eg, mechanism of injury, frac-ture classification, and BMI). One study failed to mention how outcomes were col-lected.19 Overall, these cohort studies14,19 were found to be of high methodologi-cal quality and were noted to have NOS scores of 9 and 7, respectively, of a pos-sible 9 stars.

Primary OutcomesOperative Time. Data on operative

time were available for 3 of the 4 includ-ed studies.14,17,19 The pooled mean differ-ence (MD) in operative time across all studies significantly favored the GT-entry IM nail by approximately 20 minutes (3 studies [551 patients]; MD, -20.05 [95% CI, -23.09 to -17.02]; P<.00001) (Figure 2). Subgroup analysis using data from RCTs alone also demonstrated a signifi-cant difference in operative time favor-ing the GT entry point (2 studies [201

patients]; MD, -20.88 [95% CI, -36.55 to -5.20]; P=.009).

Fluoroscopy Time. Three of the 4 studies reported total fluoroscopy time (in seconds) during IM nailing of femo-ral shaft fractures.14,17,19 The results of the pooled statistical analysis showed a significant difference in fluoroscopy time favoring the GT entry IM nail by ap-proximately 25 seconds (3 studies [551 patients]; MD, -24.55 [95% CI, -43.23 to -5.86]; P=.01) (Figure 2). A similar result was found during subgroup analysis us-ing only data from RCTs (2 studies [201 patients]; MD, -36.36 [95% CI, -59.46 to -13.26]; P=.002).

Secondary OutcomesNonunion. The pooled nonunion rate

among all patients in this study was 4.6% (26 of 570). The overall pooled nonunion rate was 3.9% (11 of 283) and 5.2% (15 of 287) for patients treated with GT-entry and PF-entry IM nails, respectively. Pooled summary of all 4 studies demonstrated no statistically significant difference in the overall risk of nonunion between pa-tients treated with a GT-entry vs PF-entry IM nail (4 studies [570 patients]; RR, 0.74 [95% CI, 0.35 to 1.58]; P=.44) (Figure 2).

Delayed Union. The number of delayed unions was reported in 3 of 4 studies.14,17,19

The pooled delayed union rate among all patients in the current review was 4.2% (23 of 551). The overall pooled delayed union rate was 3.6% (10 of 274) and 4.7% (13 of 277) for patients treated with GT-entry and PF-entry IM nails, respectively. A pooled analysis of the 3 studies showed no statis-tically significant difference in the overall

Table 4

OTA Classification of Treated Fracturesa

No. (%) of Fractures Treated

OTA Classification

With GT-Entry IM Nail

With PF-Entry IM Nail

32-A 137 (50) 100 (36)

32-B 70 (25) 103 (37)

32-C 70 (25) 75 (27)

Total 277 (100) 278 (100)

Abbreviations: GT, greater trochanter; IM, intramedullary; OTA, Orthopaedic Trauma Association; PF, piriformis fossa. aNote: Only 3 of the 4 included studies provided data on fracture classification.

Table 5

Methodological Quality Assessment for 2 Eligible RCTs Using CLEAR-NPT GuidelinesCLEAR-NPT Criteriona

Study 1 2 3 4 5 6 7 8 9 10 Explanation

Stannard et al17 Y Y Y Y U 1. U2. Y3. Y

1. U2. Y3. Y

Y Y U 4. Primary surgeon was senior resident; similar in each arm but may not have had same level of expertise as experienced surgeon. 5. Not applicable to surgi-cal intervention. 7. Not feasible. 10. No mention of analysis for missing data.

Moein et al18 U Y Y U U 1. N2. Y3. Y

1. U2. Y3. Y

1. U2. Y3. Y

Y Y 1. Patients randomized through envelopes. No informa-tion given whether envelopes introduced bias (eg, no mention of sealed opaque, etc) 4. No mention of surgeons’ expertise. 5. Not applicable to surgical intervention. 7. Not feasible. 8. No mention of who outcome assessors were.

Abbreviations: N, no; RCTs, randomized, controlled trials; U, unclear; Y, yes. a1. Adequate generation of allocation sequence; 2. Treatment allocation concealed; 3. Details of each intervention available; 4. Expertise similar in each arm; 5. Participant adherence assessed; 6. Adequate participant blinding; 7. Care providers blinded; 8. Outcome assessors adequately blinded; 9. Similar follow-up between groups; 10. Used intention-to-treat analysis.

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risk of delayed union among patients treat-ed with a GT-entry vs a PF-entry IM nail (3

studies [551 patients]; RR, 0.94 [95% CI, 0.41 to 2.14]; P=.88) (Figure 2).

Malunion. Malunion or malalignment was reported in 2 of the eligible stud-ies.14,17 One study defined malalignment as greater than 10° of angulation, greater than 15° of malrotation, and/or a leg-length discrepancy greater than 2 cm.14 This study did not report any cases of malalignment in either group; however, 1 patient in the GT-entry group healed with 12° of external rotation.14 The other study had a total of 9 fractures that healed with 5° to 8° of malalignment.17 Six patients in the PF-entry group had a malunion; 4 healed in varus and 2 healed with femoral recurvatum. Two patients in the GT-entry group healed in varus, and one healed in slight procurvatum.17

Functional Outcomes. Due to the heterogeneity in outcome measures used among the included studies, data on func-tional outcomes could not be pooled. Although each study used a different out-come measure (Harris Hip Score [HHS],19 customized functional outcome ques-tionnaire,18 Lower Extremity Measure [LEM],14 and Western Ontario and Mc-Master Universities Osteoarthritis Index [WOMAC]17), it is important to note that there were no differences in function and patient-reported outcomes between patients who received GT- and PF-entry nailing.

discussionThe current systematic review of com-

parative studies evaluating the optimal en-try point (GT vs PF) for antegrade nailing of femoral shaft fractures found the follow-ing: (1) using the GT entry point leads to significantly reduced operative times com-pared with the PF entry point; (2) fluoros-copy time is significantly less when using the GT entry point compared with the PF entry point; and (3) nonunion and delayed union rates are not significantly different among patients undergoing antegrade nail-ing via the GT and PF entry points.

The observed MD in operative time of approximately 20 minutes favoring the GT entry point is a clinically significant finding. A decrease in operative time re-

Table 6

Methodological Quality Assessment of 1 Eligible PCS and 1 Eligible RCS Using Newcastle-Ottawa Scale

Newcastle-Ottawa Scale Criterion

Selection Comparability Exposure/Outcome

Study (Study Type) 1 2 3 4 1 1 2 3

Ricci et al15 (PCS) * * * * ** * * *

Ha et al19 (RCS) * * * * ** 0 * 0

Abbreviations: PCS, prospective cohort study; RCS, retrospective cohort study. Note: Star (*)=item present. Maximum 1 star (*) for the selection and outcome components and 2 stars (**) for the comparability component.

Figure 2: Forest plots illustrating results of the pooled analysis for greater trochanter (GT) vs piriformis fossa entry for operative time (A), fluoroscopy time (B), nonunion rate (C), and delayed union rate (D). Abbreviations: CI, confidence interval; IV, inverse variance; M-H, Mantel-Haenszel.

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duces the potential morbidity associated with a longer anesthetic time and could potentially reduce intraoperative blood loss. It also reduces the economic costs associated with the surgical procedure (eg, resource use and nursing). The cost of operating room time in the United States (as per 2005 data) has been estimated to range from $22 to $133 per minute.26 These figures do not include surgeon and anesthetist fees. Thus, the potential cost savings may be substantial. Furthermore, evidence from the literature suggests that the decrease in operative time associated with use of the GT entry point is even more pronounced when considering obese patients.14,19 However, it is important to note that future conversion to a total hip arthroplasty (THA) may be more difficult after use of a GT entry nail. Although no studies have reported on conversion to THA after GT-entry IM nailing for femo-ral fractures, literature pertaining to THA conversion following cephalomedullary nailing for hip fractures has found opera-tive times and blood loss to be significant-ly greater with the GT entry point.27

The current review’s finding that the time exposed to fluoroscopy is significant-ly less (approximately 25 seconds) when using the GT entry point is another clini-cally relevant finding. Previous work has found that the average fluoroscopy time for antegrade femoral nailing can range from 0.56 minutes (31.2 seconds) to 4.60 minutes (276 seconds).28,29 The current re-sults suggest that there can be a significant reduction in radiation exposure to both the surgical team and the patient through the use of the GT entry point.

The pooled nonunion rate among all patients in this study was 4.6%, which may seem higher than the rates reported in the literature. However, nonunion rates have been found to range from 0.9% in simple femoral shaft fractures to 10% in cases of severe comminution and bone loss.8,30,31 With pooling of all fracture types (OTA 32-A/B/C) in the study, the overall nonunion rate reported here likely

reflects this varying degree of severity in fractures treated. The finding of no differ-ence in nonunion and delayed union rates between the GT and PF entry points is an important finding because it suggests that the biological healing process is not influ-enced by entry point.

The heterogeneity in outcome mea-sures used to assess postoperative func-tion in the eligible studies prevented any pooled analysis. Although no universal functional outcome measure was used, each eligible study in this review reported no significant difference in patient func-tion (as per the outcome measure used in each study) when comparing the 2 entry points.14,17-19 However, whether PF-entry nailing has a detrimental effect on the soft tissue structures around the hip is an area of controversy. In fact, Archdeacon et al32 compared hip abductor function in pa-tients who were treated for femoral shaft fractures with antegrade IM nailing using the GT or PF entry point. They found the PF-entry group had significantly less in-ternal hip abduction moment at terminal stance or push-off compared with the GT-entry group.32 In a cadaver study, Dora et al33 found that the PF entry portal was associated with significant damage to the external rotators and medial circumflex artery when compared with the GT en-try portal. Ansari Moein et al34 reported similar findings in their study of cadavers, noting that nailing through the GT would limit any surgical injury to the tendinous aspect of the hip abductor complex. How-ever, in another cadaver study by McCon-nell et al,35 the GT entry point was report-ed to cause an average of 27% damage to the gluteus medius tendon insertion. Considering the current authors’ finding of no significant difference in functional outcome between the 2 entry points, post-operative function may be independent of the entry point.

The entry site may be a more critical element in the management of subtrochan-teric fractures, which have demonstrated a propensity toward varus deformity with

the PF entry point.36,37 The deforming forces of the hip flexor and abductor mus-cles make the subtrochanteric fracture dif-ficult to treat irrespective of entry point.5 Despite this fact, there has only been one RCT examining the effect of entry point on proximal femur fractures (intertrochan-teric and subtrochanteric).20 This study found no difference in operative time, var-us malunion rate, blood loss, and incision length between the GT and PF entry points using a cephalomedullary nail.

The strength of the current systematic review is that it is the first to summarize and combine the available evidence com-paring the GT and PF entry points for ante-grade nailing of femoral shaft fractures. In addition, the authors’ search strategy was comprehensive and inclusive because they attempted to identify unpublished data by searching 3 North American orthopedic conference proceedings and did not limit results by language. Furthermore, they attempted to minimize bias throughout the study selection, data extraction, and quality assessment process by perform-ing these in duplicate. However, there are also a number of limitations to the study. First, both randomized and nonrandomized studies were pooled together in this review to increase the sample size and power for the pooled analysis. Moreover, due to the variation among the included studies in outcome measures used, it was not possible to provide any definitive conclusions on the difference in functional outcomes between patients who underwent antegrade nailing through the GT vs the PF entry portal.

conclusionThe current systematic review dem-

onstrates that use of the GT entry point during antegrade IM nailing is associated with decreased operative and fluoroscopy times, with no difference in nonunion and delayed union rates when compared with the PF entry point. Further research is required to determine the effect of each entry point on the surrounding soft tissue structures and functional outcomes.

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n Feature Article

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