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Although there is little debate that hardware should be removed in the setting of implant failure, infec-tion, nonunion, and soft-tissue com-promise, there is little consensus on routine

Indications and Expectations

Abstract

Although hardware removal is commonly done, it should not be considered a routine procedure The decision to remove hardware has significant economic implications, including the costs of the procedure as well as possible work time lost for postoperative recovery The clinical indications for implant removal are not well established There are few definitive data to guide whether implant removal is appropriate Implant removal may be challenging and lead to complications, such as neurovascular injury, refracture, or recurrence of deformity When implants are removed for pain relief alone, the results are unpredictable and depend on both the implant type and its anatomic location Current literature does not support the routine removal of implants to protect against allergy,

carcinogenesis, or metal detection Surgeons and patients should be aware of appropriate indications and have realistic expectations of the risks and benefits of implant removal

Hardware removal is frequently undertaken for symptoms at-tributed to the presence of hardware

In addition, concerns about

system-ic and local effects of retained im-plants have led many patients to re-quest elective hardware removal

Although many orthopaedic sur-geons view the procedure as a rou-tine part of care, it is sometimes more challenging and prone to com-plications than the initial surgery

Although there is little debate that hardware should be removed in the setting of implant failure, infec-tion, nonunion, and soft-tissue com-promise, there is little consensus on routine hardware removal in the set-ting of healed fracture Neither is there consensus on whether im-plants represent a risk for the patient whose vocation or avocation re-quires impact loading at that site

Furthermore, it is not clear how long patients should be protected from significant loads after hardware re-moval

Important considerations in de-termining whether to remove hard-ware include the potential for com-plications and the economic impact

To make the best decision regarding implant removal, the orthopaedic surgeon must be familiar with the potential risk of refracture or neural injury, pain caused by implants, metal sensitivity, carcinogenesis, and the possibility of implant detec-tion by security devices reported in the orthopaedic literature

Frequency and Cost

Although there are not extensive data outlining occurrence of hard-ware removal, most sources identify

Matthew L Busam, MD*

Robert J Esther, MD, MSc*

William T Obremskey, MD,

MPH

*Dual first authorship

Dr Busam is Resident, Department of

Orthopaedics and Rehabilitation,

Vanderbilt University, Nashville, TN.

Dr Esther is Resident, Department of

Orthopaedics, University of North

Carolina, Chapel Hill, NC.

Dr Obremskey is Assistant Professor,

Department of Orthopaedics and

Rehabilitation, Division of Orthopaedic

Trauma, Vanderbilt University.

None of the following authors or the

departments with which they are

affiliated has received anything of value

from or owns stock in a commercial

company or institution related directly or

indirectly to the subject of this article:

Dr Busam, Dr Esther, and Dr.

Obremskey.

Reprint requests: Dr Obremskey,

Division of Orthopaedic Trauma,

Vanderbilt University, Medical Center

East, South Tower, Suite 4200,

Nashville, TN 37232-8774.

J Am Acad Orthop Surg

2006;14:113-120

Copyright 2006 by the American

Academy of Orthopaedic Surgeons.

it as a common procedure,

account-ing for approximately 5% of all

or-thopaedic procedures done in the

United States.1In a Finnish study,

nearly all implants inserted for

frac-ture fixation (81%) were removed

af-ter fracture healing.2Removal of the

implant accounted for 29% of

elec-tive procedures and 15% of total

or-thopaedic procedures performed at

that institution during a 7-year

peri-od, compared with a removal rate of

6% of all orthopaedic cases in

Fin-land for the duration of that study

Despite the significant number of

hardware removals performed, there

is little published information

re-garding the full cost of the

proce-dure In addition to the direct costs

(ie, physician and hospital fees),

indi-rect costs include patient lost work

and productivity These costs have

not been quantified, and only a few

studies of implant removal

docu-ment patient time away from work

One study of removal of lower

ex-tremity intramedullary nails found

that patients required a mean of 11

days of sick leave.3Given the finite

resources available for medical care,

research is needed on the economic

costs of elective implant removal

Additionally, there is a need for

search into practice variations

re-garding hardware removal in the

United States

Peri-implant Fracture

and Refracture

Internal fracture fixation with either

intramedullary or extramedullary

implants creates a biologic

environ-ment that leads to adaptive changes

in bone, with the principal desired

effect of fracture healing Direct

ture healing does not produce

frac-ture callus; the new osseous

chan-nels form across the fracture site in

the environment of rigid internal

fix-ation, which is most commonly

achieved with compression plating

Indirect fracture healing with callus

formation occurs in the setting of

less rigid fixation, such as

intramed-ullary or external fixation

During the initial months of heal-ing after plate fixation, some bone mass loss is observed at the bone-plate interface Some authors at-tribute this to stress shielding, in which the plates shield the bones from normal, functional stresses leading to bone loss.4Perren et al5 at-tribute this osteopenia to the disrup-tion of blood supply caused by con-tact between the plate and the bone

They showed that osteopenia was temporary, produced even by flexible plastic plates, and occurred less of-ten and for a shorter time when the vascular supply to the bone was less disturbed This work led to the de-velopment of low-contact plates and locked plates, which cause less peri-osteal and cortical vascular disrup-tion

Multiple reports on implant moval demonstrate lower rates of re-fracture when implants are retained longer, possibly further supporting the idea that osteoporosis is a self-limited, vascular phenomenon

Beaupré and Csongradi6 retrospec-tively reviewed seven studies to ex-amine the refracture rate in 401 pa-tients from whom 459 forearm plates were removed after successful union They reported higher rates of refracture with the use of large-fragment dynamic compression plates (DCPs) (21%), compared with one-third tubular plates (0%), small-fragment DCPs (5.6%), and semitu-bular plates (6.6%).6 Removing a plate before complete fracture con-solidation increased the rate of re-fracture

A second area of concern is the stress riser at the cortical defect after screw removal In a study of drilled dog femurs, Brooks et al7reported a mean 55% reduction in energy-absorbing capacity in the presence of

a single 2.8- or 3.6-mm drill hole In

a cadaveric study, a 22% reduction

in compressive load to failure oc-curred in calcanei after drilling with

a 6.0-mm pin, the size commonly used when placing ankle-spanning

external fixators for tibial pilon frac-tures.8 However, Burstein et al9 re-ported that radiographic evidence of

a screw hole remained after the hole began to fill in with new bone New woven bone eliminated the stress-concentrating effect of the hole within 4 weeks in a canine model, even though the hole was still radio-graphically present Using single photon absorptiometry, Rosson et

al10found that bone mass in young adult men returned to close to nor-mal 18 weeks after screw removal, leading them to recommend avoid-ance of contact activity for 4 months after screw removal

Although refracture after plate re-moval cannot be completely pre-vented, the available data lead to several conclusions that can be used

to minimize the risk (1) Achieving complete union and remodeling be-fore implant removal decreases the risk of refracture (2) Avoiding un-necessary disruption of the vascular supply to the bone decreases os-teopenia Furthermore, allowing suf-ficient time for the vascular supply

to recover may correct the initial os-teopenia (3) Screw holes may re-main as stress risers for as long as 4 months

Refracture is rarely reported after removal of an intramedullary im-plant Wolinsky et al11reported on

551 fractures managed with reamed intramedullary femur fixation They removed 131 nails and reported no refractures In a study of femoral fractures in patients treated with static interlocked stainless steel nails, Brumback et al12 compared

111 fractures managed with retained implants with 103 from which the implant was removed No fractures occurred about the nail or locking screws in the first group, and only one patient refractured at the origi-nal fracture site in the second group The authors concluded that stress shielding from intramedullary nail fixation was not clinically evident once the fracture had united In addi-tion to radiographic evidence of

cir-cumferential bridging external

cal-lus, they recommend retaining the

implant for at least 12 months

post-operatively.12Although union occurs

before 12 months, the additional

time allows bone remodeling for

hy-pertrophy and strength before

hard-ware removal

Patients and physicians are often

concerned about the risk of fracture

in proximity to a retained implant

Because implants may

biomechani-cally function as stress risers,

theo-retically they may predispose a

pa-tient to peri-implant fracture (Figure

1) However, few data exist

indicat-ing an increased overall fracture risk

caused by a retained implant McKee

et al13reported three cases of fracture

occurring at the tip of a locked

hu-meral nail, all as a result of

low-energy trauma These injuries were

attributed to the type of bone in

which the implants were inserted:

humeral nails end in diaphyseal

bone, whereas femoral and tibial

im-plants end in metaphyseal bone An

analogous femoral implant is the

in-tramedullary hip screw, such as the

original Gamma nail (Stryker,

Kalamazoo, MI), a device reported to

have a risk of diaphyseal

peri-implant fracture as high as 3.1%.14

Periprosthetic fracture rates about

the hip and knee have been reported

to be as high as 2.3% and 1.2%,

re-spectively.15

Patients are often concerned

about the consequences of a new

fracture near a retained implant, but

a retained implant may be beneficial

if a second fracture occurs Figure 2,

A, demonstrates a distal tibia

frac-ture caused by a motorcycle accident

in a patient with a retained unlocked

intramedullary nail The tibial

in-tramedullary nail was reduced back

into the distal metaphysis and

re-locked without having to place a

new one (Figure 2, B)

There is no consensus concerning

the necessary amount of protection,

weight-bearing limits, or activity

modification after implant removal

The available data seem to support

Figure 1

Oblique-lateral radiograph demonstrating a peri-implant ulnar fracture caused by a retained implant The implant served as a stress riser

Figure 2

A,Lateral radiograph in a patient with a prior tibial fracture that was managed with

an intramedullary nail A repeat injury caused the nail to break out of the anterior

cortex of the distal tibia B, The retained nail simplified treatment by allowing

reimplantation and relocking of the nail in the distal tibia without the need to replace the intramedullary device

limiting impact and torsional loading

for up to 4 months.10The timing of

resuming contact activity, whether

occupational or recreational, is a

common question of patients and

their families Brumback et al,12

ac-knowledging lack of data to support

their recommendation, allowed

pa-tients to participate in sports

activ-ity with an intramedullary nail in

place for the first athletic season

af-ter fracture healing, provided the

in-terlocking screws had been removed

They recommended nail removal

upon completion of the first season

of competition Evans and Evans16

re-ported no clinical problems in 13 of

15 professional rugby players (87%)

who returned to participation with a

variety of implants in situ However,

one player reported a new,

peri-implant fracture after having open

re-duction and internal fixation (ORIF)

with plating for a both-bone forearm

fracture A second patient was

symp-tomatic in the area of a tension-band

fixation for a patellar fracture The

authors recommended allowing early

return to competitive sports with

re-tained implants because the minimal

risk is offset by competitive and

fi-nancial rewards.16

The current orthopaedic

litera-ture regarding fraclitera-ture risk from

re-tained implants does not support

ei-ther universal retention or removal

of hardware There appears to be no

significant risk of peri-implant

frac-ture when hardware is left in place,

even when the patient resumes

con-tact activity The local bone seems

to adequately remodel to correct any

deficit within 2 to 4 months after

hardware removal The decision to

remove or retain hardware cannot be

clearly decided solely on the basis of

refracture risk; therefore, other

fac-tors ought to be considered

Painful Hardware

Persistent pain after radiographic

ev-idence of fracture union commonly

leads to implant removal Rates of

implant removal vary based on

ana-tomic location and implant selec-tion In one study of 55 patients un-dergoing tension band wiring of olecranon fractures, 61% required revision surgery for painful hard-ware.17In a retrospective review of surgically treated patellar fractures,

9 of 87 patients underwent removal

of symptomatic hardware.18

It is important to consider whether the patient may reliably expect pain relief after hardware removal Brown

et al19examined functional outcomes after internal fixation of ankle frac-tures and found lower pain scores and lower scores on the Medical Out-comes Study 36-Item Short Form for patients with pain overlying the lat-eral hardware Of the 39 patients re-porting pain, 22 underwent removal

of hardware, but only 11 (50%) of those had improved lateral ankle pain These data contrast with that of Jacobsen et al,20 who reported im-provement after hardware removal in 75% of patients who had previously undergone ORIF of the ankle

Pain relief following femoral in-tramedullary nail removal is simi-larly unpredictable In their retro-spective review of 80 patients with femoral fractures, Dodenhoff et al21 noted that 11 of 17 who underwent implant removal experienced pain re-lief With tibial implants, knee pain

is a common indicator for nail re-moval Keating et al22showed a 45%

rate of complete relief of knee pain after tibial nail removal; 35% of pa-tients experienced partial relief and 20%, no relief In a retrospective re-view of 169 patients, Court-Brown et

al23 noted complete pain relief in 27% and marked relief in 69% after nail removal However, 3.2% re-ported worsening pain after hardware removal In another study, 17% of pa-tients noted an increase in knee pain after tibial nail removal.3Because the extent of pain relief varies after hard-ware removal, the surgeon must ex-ercise caution in attributing persis-tent pain to retained implants No patient should be guaranteed com-plete pain relief

Fixation Across Joints

Preventing implant failure is a com-mon indication for removal The cy-clic loading associated with fixation across joints often leads to fatigue failure of metallic implants Because

of this concern, hardware is often re-moved from the distal tibiofibular syndesmosis after ankle injury fixa-tion as well as from the midfoot af-ter fixation of Lisfranc joint injuries Removal versus retention of ankle syndesmosis transfixion screws re-mains controversial There are no prospective, randomized studies comparing the results of retention versus removal of syndesmosis screws Some authors routinely re-move the implant before unrest-ricted weight bearing,24but DeSouza

et al25 reported no complications from screw retention and removed screws only from those patients who were symptomatic on palpation or who requested removal Kuo et al26 followed 48 patients who underwent ORIF for Lisfranc joint injuries for an average of 52 months (range, 13 to 144) Twenty-eight patients required hardware removal secondary to pain, but the remainder demonstrated no clinical problems with the retained hardware

Another concern is the immobil-ity created by fixation across pelvic joints Displaced fractures of the an-terior and posan-terior pelvic ring rou-tinely require fixation spanning the symphysis pubis and the sacroiliac joints Displaced pelvic fractures in female patients have been associated with negative effect on genitouri-nary and reproductive function.27To date, no studies have been able to de-termine the ability of a female pa-tient to have a vaginal delivery after undergoing pelvic fracture fixation However, obstetricians are generally unwilling to have their patients at-tempt vaginal delivery in the setting

of symphyseal or sacroiliac fixation This concern may be an indication for hardware removal in young fe-male patients

Metal Allergy

Implants with nickel or chromium

composition cause allergic

respons-es in a small segment of the

popula-tion A review of approximately 50

studies shows the prevalence of

met-al sensitivity in the genermet-al

popula-tion to be 10% to 15%.28In fracture

surgery, the incidence of sensitivity

to any of the three ions in stainless

steel (ie, chromium, nickel, cobalt)

seems to be low (0.2%, 1.3%, and

1.8%, respectively).29 Because of

concerns about hypersensitivity to

any of these ions, some authors have

proposed using titanium implants in

patients known to be allergic to the

components of stainless steel

A patient who has metal

sensitiv-ity or a nickel allergy may report

nonspecific deep generalized pain

over the area of injury and implant

It is very difficult to differentiate

this nonspecific pain from either

pain caused by the local injury or

mechanical pain related to the

im-plant An example of clinical

infor-mation that may suggest a metal

sensitivity is the presence of

symp-toms in a fair-skinned, red-haired

woman with a history of earlobe

ir-ritation caused by earrings that are

not 14-carat gold or caused by

cos-tume jewelry The patient also may

be sensitive to medications and

have multiple allergies Patients

with sensitivity or allergy will

ex-press significant relief almost

im-mediately after hardware removal

It is not yet known whether metal

sensitivity plays a notable role in

implant failure in fracture surgery,

or whether it is merely an unusual

complication for a limited number

of patients Additionally, it is not

known whether there is a

cause-and-effect relationship between

metal sensitivity and implant

loos-ening Currently, there is no

evi-dence of an increased risk of implant

failure in patients with positive skin

patch testing sensitivity.30

Carcinogenicity

Because younger patients may re-quire insertion of metal implants, the carcinogenic risk of these im-plants must be assessed The associ-ation between metallic implants and tumors has been established in ex-perimental animals.31In the absence

of chronic infection, the pathogene-sis of metal-induced carcinogenepathogene-sis may fall into two general categories:

(1) metal-ion binding to DNA and (2) alteration of DNA and protein syn-thesis Because binding is reversible, other effects are likely to be involved

in carcinogenesis Evidence points to reactive oxygen species created dur-ing corrosion and their effects on DNA and proteins as the likely sec-ond culprit in metal-induced car-cinogenesis.32 Although basic sci-ence and animal studies may point

to a correlation between metallic implants and cancer, one must be careful not to ascribe carcinogenesis

to retained implants

There are fewer than 30 human cases of implant-associated tumors

in the literature The limitations of such case reports is that the denom-inator is not known, making it im-possible to quantify risk Moreover,

it is extremely difficult to differenti-ate correlation from causation when trying to establish a relationship be-tween implants and tumors Gener-ally, sarcomas related to implants tend to be high-grade and occur many years after initial placement of the device.33There is no consensus, however, that implants pose a signif-icant risk for local tumor develop-ment The overall risk, if any, ap-pears to be very low

The great majority of data related

to cancer risk and metallic implants

is found in the total joint literature

Gillespie et al34reported a 70% in-crease in hematopoietic cancers over the general population in their retro-spective review of 1,358 total joint patients over a 10-year period Those results have not been duplicated in other studies, however In the largest

study to date, Signorello et al35 con-ducted a nationwide cohort study in Sweden to examine cancer incidence

in 116,727 patients who underwent total hip replacement from 1965 through 1994 Overall, they found

no increased risk of cancer compared with the general population, but they did note slight increases in prostate cancer and melanoma as well as a reduction in stomach can-cer Long-term follow-up (>15 years) showed an increase in multiple my-eloma and a statistically insignifi-cant increase in bladder cancer The authors found no increase in bone or connective tissue cancer in either sex in any follow-up period.35 The risk of carcinogenicity associated with metallic implants appears to be very small and does not warrant the routine removal of hardware

Metal Detection

In this era of heightened security at venues ranging from airports and sporting events to hospital

emergen-cy departments and high schools, pa-tients frequently inquire about the possibility that an implant will set off a metal detector In 1992, Pearson and Matthews36 tested a variety of arthroplasty and fracture implants They postulated that only those im-plants with sufficiently high iron content would be detected and that because modern implants have lit-tle, if any, iron, detection is

unlike-ly In 1994, Beaupre37corrected that earlier assertion, explaining that 316L stainless steel is actually 60% iron Detection depends on an ob-ject’s permeability (ability to tempo-rarily disrupt a magnetic field) and conductivity Because modern pro-cessing techniques limit permeabil-ity and conductivpermeabil-ity, the potential for detection is very low

The incidence of implant detec-tion during security screening may

be low, but many orthopaedic sur-geons provide their patients with wallet cards containing a short statement providing

documenta-tion of a metallic implant as well as

a telephone number that

appropri-ate authorities may use to further

confirm the presence of implanted

metal Our experience with a joint

arthroplasty and airport travel is

that the screeners do not pay

atten-tion to an implant card Given the

low likelihood of detection by

secu-rity measures, removing metallic

implants to avoid travel concerns is

not warranted at this time

Pediatric Patients

The general practice at many

institu-tions is to offer removal of implants

to pediatric patients The reasons cited for removing pediatric implants include difficulty in removing im-plants later because of exuberant cal-lus overlying the implant, stress shielding, risk of corrosion, metal al-lergy, and potential carcinogenesis

Concern about degenerative pro-cesses and the consequences of re-tained hardware when addressing later fractures also has driven the routine removal of implants in chil-dren The same concerns may be ex-pressed in adults, but adults have fewer expected years of risk for com-plications No data are available con-cerning the frequency of a retained implant’s posing a technical problem

in the patient undergoing surgery for

a second fracture or for joint degen-eration in that extremity

Flexible intramedullary rods used for treating pediatric fractures are routinely removed after bony union

There are no data in the literature re-garding whether these implants should be removed or what the con-sequences are if they are left in place In a recent review of flexible nailing of pediatric femoral frac-tures, hardware removal was not un-dertaken routinely.38 Removal of flexible intramedullary nails in chil-dren is frequently as difficult as or more difficult than implantation and requires larger incisions (Figure 3)

Of the two major complications in the study by Luhmann et al,38 one was a septic knee following implant removal

Removal of implants used for treating a slipped capital femoral epiphysis (SCFE) is also routinely done, but not without risk

of complications According to Swiontkowski,39a major complica-tion is blood loss and surgical time exceeding that of the original proce-dure He noted such difficulty in 11

of 18 cases of SCFE hardware

remov-al (61%) In another series of implant removal in patients with SCFE, four

of seven patients (57%) undergoing implant removal had complications, such as breakage of the retained

im-plant or intraoperative fracture.40 Kahle41reported an overall compli-cation rate of 13% in pediatric hard-ware removal but a 42% rate in SCFE hardware removal Based on these numbers, some surgeons ques-tion the practice of routine hardware removal in children Kahle41stated that “there is very little clinical or experimental evidence to support a policy of routinely removing asymp-tomatic internal fixation devices.” There are no clear data in the lit-erature regarding routine removal of pediatric implants Chapman states,

in the orthopaedic textbook that he edited, “In children we advise rou-tine removal of implants.”42

Howev-er, Green and Swiontkowski43do not recommend (and even discourage) routine removal of implants except

in the pelvis and proximal femur, where retained hardware could be problematic during secondary recon-structive procedures As with any elective procedure, parents need to

be aware of the risks and benefits of hardware removal in the pediatric population

Surgical Complications

Any surgical procedure carries inher-ent risks, including wound compli-cations, iatrogenic injury, and anes-thetic complications In their report

on implant removal in 86 patients, Richards et al44noted a 3% compli-cation rate, including one refracture, one radial nerve injury, and one he-matoma Sanderson et al45reported

an overall 20% complication rate in their series of 188 patients The most common complication was in-fection, followed by nerve injury They recommend senior surgeon su-pervision of forearm hardware re-moval; unsupervised junior surgeons produced three permanent nerve in-juries.45 Langkamer and Ackroyd46 reported on 55 patients who had forearm plate removal They noted a 40% complication rate, including 4 infections, 5 poor scars, 17 nerve problems, 1 delay in wound healing,

Figure 3

Anteroposterior view of a retained

flexible intramedullary nail after

management of a pediatric femur

fracture

and 2 refractures They

recommend-ed leaving asymptomatic hardware

in place and not delegating the

pro-cedure to inexperienced surgeons

They reported complication rates of

13%, 60%, and 100% in cases

per-formed by experienced surgeons,

moderately experienced surgeons,

and inexperienced surgeons,

respec-tively

Takakuwa et al47reported on four

intraoperative fractures of the tibia

during elective removal of a slotted

intramedullary tibial nail Given

this risk, the surgeon should

consid-er intraopconsid-erative fluoroscopy to

con-firm that no new fracture has

oc-curred Furthermore, informing the

patient about the possible risks of

nail removal remains paramount

Summary

Hardware removal, although a

com-mon operation, should not be

under-taken lightly and should not be a

routine procedure Although it is

clearly indicated in some instances,

the habitual removal of implants is

not supported by the literature and

exposes the patient to unnecessary

costs and complications Even in

pa-tients reporting implant-related

pain, removal of that implant does

not guarantee relief and may be

asso-ciated with further complications,

including infection, refracture, nerve

damage, and worsening pain

Addi-tionally, patients may request or

sur-geons may recommend removal on

unproved grounds, such as

protec-tion from neoplasm or reducprotec-tion of

stress shielding No data suggest

that implant removal accomplishes

these objectives or that retained

im-plants increase the risk of neoplasm

or cause stress shielding As with

any surgical procedure, it is

impor-tant to understand the expected

ben-efits from the procedure as well as to

know the inherent risks More

re-search is needed regarding the

tim-ing and expected benefits of

remov-ing implants as well as the direct and

indirect costs of the procedure

References

Evidence-based Medicine:There are

no level I or level II evidence-based studies in the articles referenced

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