Spinal Surgery
and Patient Safety:
A Systems Approach
Abstract
In every spinal procedure, identifying the specific patient, proper
surgical site, and pathologic lesion for surgical intervention are
crucial patient safety concerns. The 1999 Institute of Medicine
report “To Err is Human” identified adverse events associated with
surgery. Both the American Academy of Orthopaedic Surgeons and
the North American Spine Society have had voluntary, systems-
based programs in place for several years to address wrong patient,
wrong procedure, and wrong site surgery. Beginning July 1, 2004,
the Joint Commission on the Accreditation of Healthcare
Organizations mandated that hospitals comply with the JCAHO
Universal Protocol. In addition to surgical site marking, the
protocol incorporates additional factors, such as calling a time out
before skin incision to do a final systems check of patient
identification, surgical site, records, imaging studies, equipment,
and review of preoperative medication.
C
rucial to patient safety in any
spinal surgery is ensuring that
the correct patient, the proper surgi-
cal site, and the extent of the patho-
logic lesion are all properly and pre-
cisely identified. Although the
initial reaction to this assertion is
likely to be that these issues are in-
herent in the performance of any
surgical procedure, on reflection,
these processes constitute a prime

course of treatment. The evaluation
of contributing factors led to the de-
scription of medicine as a prime
model of a complex interactive sys-
tem. As such, a systems methodol-
ogy may be applied in order to frame
both an analysis of existing problems
and strategies for potential solutions.
David A. Wong, MD, MSc,
FRCSC
Dr. Wong is Director, Advanced Center
for Spinal Microsurgery, Presbyterian/
St. Luke’s Medical Center, Denver, CO.
Dr. Wong is also Past President, North
American Spine Society; Chairman,
AAOS Patient Safety Committee; and
Chairman, NASS Patient Safety Task
Force.
Dr. Wong or the department with which
he is affiliated has received research or
institutional support from Stryker, Arcus
Centerpulse. Dr. Wong or the
department with which he is affiliated
has received nonincome support (such
as equipment or services), commercially
derived honoraria, or other
non-research–related funding (such as
paid travel) from Stryker. Dr. Wong or
the department with which he is
affiliated serves as a consultant to or is

Interestingly, these inci-
dents were considered “negligent”
(therefore, likely preventable) in
17.7% of the New York cases
3
and in
35.1% of the cases in Colorado and
Utah.
4
By a large margin, antibiotics
were the largest medication class of
concern. The most consistent oppor-
tunity for problems regarding antibi-
otics for spinal surgery is in the se-
lection and timely administration of
preoperative prophylactic antibiot-
ics. A specific history of patient al-
lergy to antibiotics should be ob-
tained from the medical record and
solicited from the patient before per-
forming any surgical procedure.
3,4
The AAOS recently published an
advisory statement on prophylactic
antibiotics, outlining guidelines for
medication selection and timing of
preoperative antibiotic prophylaxis.
5
Although joint arthroplasty is the pri-
mary focus of the advisory statement,

Reviews of
medical records indicated that ap-
proximately 17% of the adverse
events in both series were consid-
ered negligent.
3,4
Technical errors during surgery
made up the largest category of sur-
gical adverse events. The IOM report
did not break down technical errors
more specifically, but other studies
have specified the most frequent
technical complications in spine
surgery, including dural tears,
6-11
bat-
tered root syndrome,
12,13
incomplete
decompression,
14-17
development of
instability,
18
and wrong level sur-
gery.
19
Antonacci and Eismont
11
sug-

mandated Joint Commission on the
Accreditation of Healthcare Organi-
zations (JCAHO) Universal Protocol
for avoiding wrong patient, wrong
site, and wrong procedure surgery.
22
Wrong Site Surgery:
Historical Perspective
In North America, the issue of
wrong site surgery was first high-
lighted in a closed claims analysis by
the Canadian Medical Protective As-
sociation, Canada’s national mal-
practice insurance carrier. The data
were additionally reviewed by a
committee of the Canadian Ortho-
paedic Association chaired by Paul
Wright, MD.
23
In the United States,
Terry Canale, MD, chaired the
AAOS Task Force on Wrong Site
Surgery, which performed a closed
claims review of wrong site surgeries
in the United States.
20
Additional
data have come from analysis of the
Sentinel Event program of the
JCAHO.

gery since the inception of the vol-
untary Operate Through Your Ini-
tials program.
23
Sign, Mark and X-Ray
Program
The SMaX program
21
contains three
key elements performed in three
steps: (1) reviewing the medical
records, including imaging studies, to
confirm patient identification, the
site of surgery, and the procedure to
be performed; (2) specifying the side
of surgery as part of the site marking
process; and (3) confirming the spinal
level of pathology intraoperatively
(Table 1). The steps involved in
checking these key elements are:
(1) completing the preoperative
checklist, (2) signing the surgeon’s
initials on the patient’s extremity or
trunk to identify the side to be ap-
proached as well as to serve as an ini-
tial approximation of level, and (3) in-
traoperatively marking a fixed, bony
landmark and taking a radiograph for
final identification of the spinal level.
The SMaX checklist (Figure 1),

daunting. A reliable system must be
established at each treatment center
to ensure that relevant records are
available at the time of surgery.
The second step in the SMaX pro-
gram, identifying the side of surgery,
is literally a “sign” intervention.
The trunk or neck on the side of the
surgical procedure is marked with
the surgeon’s initials to establish the
definitive side of surgical interven-
tion. This usually correlates with
the patient’s side of dominant symp-
toms. With a bilateral procedure, ini-
tialing the general location on either
side will suffice.
The last component of SMaX is
performed in the operating room. Fi-
nal documentation of levels is con-
firmed by radiographic examination.
A radiopaque marker (eg, needle,
towel clip, Kocher clamp) is used to
identify a bony landmark (eg, pedicle,
spinous process). A needle positioned
just below the facet will generally lo-
calize the top of the pedicle. When
the spinous process is employed, cor-
relation with preoperative plain ra-
diographs will help localize the vari-
able superior/inferior relation of the

any surgical procedure, the surgeon
must ensure that the pathologic level
is accurately identified. This is most
reliably performed by obtaining an
MRI spanning the thoracic pathol-
ogy, extending either up to the base
Table 1
The Identification Process According to the North American Spine Society
Sign, Mark and X-ray (SMaX) Program
Correct patient Verbal name check with patient
Confirm ID bracelet
Correlate medical records: written notes, laboratory
reports, imaging studies, consent forms
Proper side of
surgery
With patient participation, when feasible
Surgeon or credentialed provider (eg, fellow, resident,
physician assistant), who is a member of the patient’s
surgical team, marks skin for first site marking with
indelible ink, on the neck or torso, in the general area of
surgery, and on the proper side of surgery (when a
unilateral approach is planned)
Appropriate
spinal level
Final localization of surgical level intraoperatively via
radiograph, bony landmark, metal marker
Spinal Surgery and Patient Safety: A Systems Approach
228 Journal of the American Academy of Orthopaedic Surgeons
of the skull or down to the sacrum.
Levels may then be counted directly.

cent graphite operating frame, which
offers the option of both AP and lat-
eral views.
In the cervical spine, lateral radio-
graphs are the most commonly used
in both anterior and posterior ap-
proaches for correlating a marked
level with reliably identified upper
cervical segments. Where the shoul-
ders would obscure a marker in the
lower cervical area, the exposure
may have to be extended up to allow
marking of an unobstructed level.
Direct counting down to the point of
pathology may then be dependably
performed.
JCAHO Sentinel Event
Program: Not Just
Wrong Site
Since 1995, the JCAHO Sentinel
Event program has monitored the in-
cidence of “wrong site” surgeries.
From its inception through 2003,
278 incidents of wrong site surgery
were reported.
24
On further review of
the data, it was found that this cate-
gory, wrong site, in fact comprised
several clinically important subcat-

tration of preoperative medications
(eg, antibiotics); and the presence of
appropriate medical records, imag-
ing, and equipment (Table 2). Both
the AAOS and NASS had consider-
able input in the development of the
JCAHO Universal Protocol, and
many of the elements of the SYS and
SMaX programs were incorporated
into the JCAHO methodology. Both
the AAOS and NASS have endorsed
the Universal Protocol.
Site Marking is Not
Enough: Why a Systems
Approach is Needed
In the following example, site mark-
ing alone likely would not have pre-
vented an adverse event. Figure 3, A
is a sagittal, T2-weighted MRI scan
of a man whose chief complaint was
sciatica. The radiologist identified a
rudimentary disk at the lumbosacral
junction, judged it to be a transition-
al level, and designated this segment
as S1-2. According to this numbering
system, the herniated disk is at the
next level cephalad, L5-S1. Using a
grease pencil, the radiologist num-
bered the vertebrae accordingly on
the film. Unfortunately, the official

in Figures 3, A and B, the concerns
raised by Figure 3, C—the intraoper-
ative localization radiograph—can
be anticipated. The surgeon’s dictat-
ed surgical report indicates that a
laminotomy/diskectomy was per-
formed at the L5-S1 level, which is
the location of the herniated disk de-
scribed in the written MRI report
from the radiologist. However, the
intraoperative radiograph shows the
Taylor retractor and the probe mark-
ing the disk at the transitional level.
In fact, were the radiologist’s num-
bering scheme to be used, this is the
S1-2 segment. The herniated disk is
actually at the level above.
Surgical site marking alone would
not have avoided this wrong level
surgery. This example represents an
instance of systems failure within
the framework of medicine as a
complex interactive system. Simi-
larly, site marking would not avoid a
Figure 2
Joint Commission on Accreditation and Healthcare Organizations analysis of
Sentinel Events reported under the wrong site surgery category.
Table 2
Elements of the Joint Commission on the Accreditation of Healthcare
Organizations Universal Protocol

confirming patient medication aller-
gies, and ensuring that antibiotics
have been given and that required
equipment is available for the case.
Table 3 summarizes the issues to be
addressed in both preoperative hold-
ing and the operating room. PRE-
PARE, the acronym developed by
John M. Purvis, MD, was the win-
ning submission in the 2004 AAOS
Patient Safety Tip contest.
25
Table 3
Systems Approach to Avoiding Wrong Patient, Wrong Site, Wrong
Level Surgery
Preoperative Holding (PREPARE)
P Procedure/
Plan
Discuss everything with the operating room team
R Radiology Images in the room, equipment requested
E Equipment Implants and supplies available and in working
order
P Patient Correct patient: check ID bracelet, surgical site
marked
A Anesthesia Be aware of the surgical plan, positioning, special
needs (eg, hypotension)
R Rx given Prophylactic antibiotics, patient-specific medications
E Exceptions Any special considerations
Surgery/Operating Room (TOR)
TO Time out Check patient identity, records, imaging, surgical

steps outlined in those programs
also ensures compliance with the
JCAHO Universal Protocol.
References
Citation numbers printed in bold
type indicate references published
within the past 5 years.
1. Why do er rors happen? in Institute
of Medicine: To Err is Human:
Building a Safer Health System.
Washington, DC: National Academy
Press, 1999, pp 49-68. Available at
http://www.nap.edu/books/03090683
71/html/49.html. Accessed Novem-
ber 21, 2005.
2. WongDA: It’s more than humanerror:
A systems approach to patient safety.
SpineLine May/June 2002;3:20-21.
3. Brennan TA, Leape LL, Laird NM, et al:
Incidence of adverse events and negli-
gence in hospitalized patients: Results
of the Harvard Medical Practice Study
I. N Engl J Med 1991;324:370-376.
4. Thomas EJ, Studdert DM, Burstin HR,
et al: Incidence and types of adverse
events and negligent care in Utah and
Colorado. Med Care 2000;38:261-
271.
5. AAOS Advisory Statement: Recom-
mendations for the use of intravenous

11. Antonacci MD, Eismont FJ: Neuro-
logic complications after lumbar
spine surgery. J Am Acad Orthop
Surg 2001;9:137-145.
12. Bertrand G: The “battered” root prob-
lem. Orthop Clin North Am 1975;6:
305-309.
13. Balderston RA, An HS: Complica-
tions in Spinal Surgery. Philadelphia,
PA: WB Saunders, 1991.
14. Herkowitz HN, Garfin SR: Decom-
pressive surgery for spinal stenosis.
Seminars in Spine Surgery 1989;1:
163-167.
15. Macnab I: Negative disc exploration:
An analysisof the causes ofnerve-root
involvement in sixty-eight patients.
J Bone Joint Surg Am 1971;53:891-
903.
16. Epstein JA, Epstein BS, Rosenthal AD,
Carras R, Lavine LS: Sciatica caused
by nerve root entrapment in the later-
al recess: The superior facet syn-
drome. J Neurosurg 1972;36:584-589.
17. Burton CV, Kirkaldy-Willis WH,
Yong-Hing K, Heithoff KB: Causes of
failure of surgery on the lumbar spine.
Clin Orthop 1981;157:191-199.
18. Johnsson KE, Redlund-Johnell I, Udén
A, Willner S: Preoperative and postop-

levels of wrong sided surgery. COA
Bulletin ACO February/March
2002:10.
24. Sentinel Event Alert. Oakbrook, IL:
Joint Commission on the Accredita-
tion of Healthcare Organizations.
December 5, 2001. Available at http://
www.jcaho.org/about+us/news+let
ters/sentinel+event+alert/sea_24.htm.
Accessed February 23, 2006.
25. Porucznik MA: Patient safety tip
contest winners announced. AAOS
Bulletin 2004;52:37. Available at
http://www.aaos.org/wordhtml/bulle
tin/apr04/acdnws2.htm. Accessed
November 21, 2005.
Spinal Surgery and Patient Safety: A Systems Approach
232 Journal of the American Academy of Orthopaedic Surgeons