CLINICAL ARTICLE
J Neurosurg Spine 28:630–641, 2018
Retrospective single-surgeon study of 1123 consecutive
cases of anterior cervical discectomy and fusion: a
comparison of clinical outcome parameters, complication
rates, and costs between outpatient and inpatient surgery
groups, with a literature review
Jack Mullins, BS,1 Mirza Pojskić, MD,2 Frederick A. Boop, MD,3,4 and
Kenan I. Arnautović, MD, PhD3,4
College of William & Mary, Williamsburg, Virginia; 2Department of Neurosurgery, University of Marburg, Germany; 3Semmes
Murphey Neurologic & Spine Institute; and 4Department of Neurosurgery, University of Tennessee Health Science Center,
Memphis, Tennessee
1
OBJECTIVE Outpatient anterior cervical discectomy and fusion (ACDF) is becoming more common and has been reported to offer advantages over inpatient procedures, including reducing nosocomial infections and costs, as well as improving patient satisfaction. The goal of this retrospective study was to evaluate and compare outcome parameters, complication rates, and costs between inpatient and outpatient ACDF cases performed by 1 surgeon at a single institution.
METHODS In a retrospective study, the records of all patients who had undergone first-time ACDF performed by a
single surgeon in the period from June 1, 2003, to January 31, 2016, were reviewed. Patients were categorized into 2
groups: those who had undergone ACDF as outpatients in a same-day surgical center and those who had undergone
surgery in the hospital with a minimum 1-night stay. Outcomes for all patients were evaluated with respect to the following parameters: age, sex, length of stay, preoperative and postoperative pain (self-reported questionnaires), number of
levels fused, fusion, and complications, as well as the presence of risk factors, such as an increased body mass index,
smoking, and diabetes mellitus.
RESULTS In total, 1123 patients were operated on, 485 (43%) men and 638 (57%) women, whose mean age was 50
years. The mean follow-up time was 25 months. Overall, 40.5% underwent 1-level surgery, 34.3% 2-level, 21.9% 3-level,
and 3.2% 4-level. Only 5 patients had nonunion of vertebrae; thus, the fusion rate was 99.6%. Complications occurred
in 40 patients (3.6%), with 9 having significant complications (0.8%). Five hundred sixty patients (49.9%) had same-day
surgery, and 563 patients (50.1%) stayed overnight in the hospital. The inpatients were older, were more commonly male,
and had a higher rate of diabetes. Smoking status did not influence the length of stay. Both groups had a statistically
significant reduction in pain (expressed as a visual analog scale score) postoperatively with no significant difference between the groups. One- and 2-level surgeries were done significantly more often in the outpatient setting (p < 0.001).
The complication rate was 4.1% in the outpatient group and 3.0% in the inpatient group; there was no statistically significant difference between the 2 groups (p = 0.339). Significantly more complications occurred with 3- and 4-level surgeries than with 1- and 2-level procedures (p < 0.001, chi-square test). The overall average inpatient cost for commercial
insurance carriers was 26% higher than those for outpatient surgery.
CONCLUSIONS Anterior cervical discectomy and fusion is safe for patients undergoing 1- or 2-level surgery, with a
very significant rate of pain reduction and fusion and a low complication rate in both clinical settings. Outpatient and
inpatient groups undergoing 3- or 4-level surgery had an increased risk of complications (compared with those undergoing 1- or 2-level surgery), with a negligible difference between the 2 groups. This finding suggests that these procedures
can also be included as standard outpatient surgery. Comparable outcome parameters and the same complication rates
between inpatient and outpatient groups support both operative environments.
https://thejns.org/doi/abs/10.3171/2017.10.SPINE17938
KEYWORDS ACDF; complication rate; inpatient surgery; outpatient surgery; cervical
ABBREVIATIONS ACDF = anterior cervical discectomy and fusion; ASA = American Society of Anesthesiologists; BMI = body mass index; LOS = length of stay; NIS =
National (Nationwide) Inpatient Sample; NSQIP = National Surgical Quality Improvement Program; VAS = visual analog scale.
SUBMITTED August 29, 2017. ACCEPTED October 17, 2017.
INCLUDE WHEN CITING Published online March 30, 2018; DOI: 10.3171/2017.10.SPINE17938.
630
J Neurosurg Spine Volume 28 • June 2018
©AANS 2018, except where prohibited by US copyright law
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
A
nterior cervical discectomy and fusion (ACDF)
is considered the gold standard for many degenerative diseases of the cervical spine because of
its relative simplicity, minimal risk, and reliability.8 It was
first described by several authors in 19585,31 and has become established as one of the most common spine procedures. A recent population-based observational study
revealed a steady increase in cervical spine surgeries in
both inpatient and outpatient settings.3
The increasing interest in cost-saving strategies has
shifted many medical procedures to outpatient and ambulatory surgery centers.1 Ambulatory surgery comprised 9%
(5.6 cases per 100,000 capita) of all cervical procedures
in 2005 and 13% (9.0 cases per 100,000 capita) in 2009,
constituting a 60.5% increase, whereas inpatient surgeries
increased 8.7% over the same period.3 The safety of outpatient surgery has been demonstrated in spine surgery.6,24
In addition, the facility fees for ambulatory surgery centers are about 70% of those in the inpatient hospital setting.21 Thus, outpatient single-level ACDF procedures are
becoming more common and offer advantages, such as
reduced nosocomial infections and costs and improved
patient satisfaction.12,13
Several studies have analyzed outcomes and complication rates for outpatient ACDF, while others have compared inpatient and outpatient ACDF. Four studies were
based on an analysis of the American College of Surgeons
National Surgical Quality Improvement Program (NSQIP)
database.1,10,13,16,18,19,21,25,29,32,34,36
Here, we conducted the first single-institution, singlesurgeon comparison of outcomes between inpatient and
outpatient ACDF with the advantage of diminishing the
discrepancies that can arise from differences in the experience, technique, treatment protocol, and expertise of different surgeons. Like other authors, we analyzed 1- and
2-level surgeries, but we also evaluated patients who had
undergone 3- and 4-level surgeries. For the first time, 3-level surgery was established as a standard procedure in the
outpatient setting. The goal of this retrospective study was
to evaluate and compare outcomes, complication rates, and
costs between inpatient and outpatient ACDF procedures
done by a single surgeon. We also reviewed the literature
comparing outcome parameters between inpatient and
outpatient ACDF.
Methods
After obtaining study approval from the appropriate
hospital institutional review board (Baptist Memorial Hospital/Semmes Murphey Clinic), we evaluated the records
for all patients who had undergone first-time ACDF for
cervical radiculopathy and/or myelopathy due to degenerative disc disease and/or cervical spinal canal stenosis. Over
a 13-year period (from June 1, 2003, to January 31, 2016),
surgeries were performed by the senior author, who used
a standard anterior approach from the left side. Fusion
was achieved using cadaver allografts (Medtronic Inc.)
with the Vision Elite titanium plate and various screws
(Medtronic Inc.). Operative reports, hospital and outpatient clinic charts, and radiographic studies were independently reviewed by 2 individuals. Differences in findings
were adjudicated during a review conference that included
all authors.
The patients were categorized into 2 groups: those who
had undergone ACDF as an outpatient procedure (sameday discharge) and those who had undergone surgery in
the metropolitan area hospital (inpatients) with a minimum 1-night stay (overnight stay). General indications for
the procedure were pain that had not resolved with conservative therapy (pain medication and at least 8 weeks of
physical therapy) and the presence of neurological deficits.
The decision to perform surgery in either the inpatient or
outpatient setting was based on several indicators, most
importantly, the presence of comorbidities and the type of
health insurance. Patients who had Medicare were admitted to stay overnight. Furthermore, older patients (age >
65 years) and patients with comorbidities who had a preoperative American Society of Anesthesiologists (ASA)
physical status classification of III or IV stayed overnight.
Patients who went home on the same day were observed
for up to 6 hours postoperatively and were followed up via
phone interview for 4 postoperative days.
Outcomes for all patients were evaluated with respect
to the following parameters: age, sex, length of stay (LOS),
preoperative and postoperative pain (both from self-reported questionnaires), number of levels fused, fusion, and
complications, as well as the presence of risk factors, such
as increased body mass index (BMI), smoking, and diabetes mellitus. Outcomes for the inpatient group were compared with those for the outpatient group. A cost analysis
was also done for both groups.
Statistical Analysis
Data were recorded using descriptive statistical methods. The Mann-Whitney U-test was used to compare
samples. The chi-square test and Fisher’s exact test were
used to assess differences between groups. The level of
significance was set at p = 0.05. Statistical analysis was
performed using MedCalc Statistical Software version
14.12.0 (MedCalc Software bvba).
Results
Overall Patient Characteristics
Overall patient characteristics are summarized in Table
1. The median follow-up was 25 months (SD 5.63, range
11–56 months).
Age and Sex
Overall, 1123 patients were operated on, 485 (43%) of
whom were men and 638 (57%) of whom were women.
The median patient age was 50 years (Fig. 1).
Risk Factors
Overall, 172 patients (15.3%) had diabetes mellitus,
which affected patients equally by sex. Three hundred
eighty-nine patients (34.6%) used tobacco; among these
patients, there were significantly more men (192, 17% of
overall group; p = 0.002, Fisher’s exact test). According
to anthropometric measurements, men were significantly
taller and heavier, but there were no significant differences
between the sexes in terms of BMI characteristics.
J Neurosurg Spine Volume 28 • June 2018
631
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
TABLE 1. General characteristics of patients who underwent ACDF
Sex
Parameter
No. of patients
Median age in yrs (IQR)
Risk factor (no. [%])
Diabetes mellitus
Smoking
Total
Median height in inches (IQR)
Median weight in lbs (IQR)
Median BMI (IQR)
Surgical level (no. [%])
1
2
3
4
LOS (no. [%])
Outpatient
Inpatient
LOS (no. [%])
Same day
1 night
2 nights
≥3 nights
Median FU in mos (IQR)
Median preop VAS pain score (IQR)
Median postop VAS pain score (IQR)
Male
Female
Overall
p Value
485
51 (44–58)
638
49 (43–57)
1123
50 (43–58)
0.090†
76 (15.67)
192 (39.59)
268 (55.26)
70 (68–72)
202.1 (178.3–232)
29.5 (26.5–32.9)
96 (15.05)
197 (30.88)
293 (45.92)
64 (62–66)
173.8 (150–205)
30.2 (26.1–34.7)
172 (15.32)
389 (34.64)
561 (49.96)
67 (64–69)
187.9 (160–215)
29.8 (26.3–33.8)
198 (40.82)
158 (32.58)
108 (22.27)
21 (4.33)
257 (40.28)
228 (35.74)
138 (21.63)
15 (2.35)
455 (40.52)
386 (34.34)
246 (21.91)
36 (3.21)
229 (47.22)
256 (52.78)
331 (51.88)
307 (48.12)
560 (49.87)
563 (50.13)
0.802‡
0.002‡
<0.001†
<0.001†
0.519†
0.234*
0.132‡
0.009§
229 (47.22)
224 (46.19)
16 (3.30)
16 (3.30)
25 (21–30)
7.5 (6–8.5)
0 (0–2)
331 (51.88)
286 (44.83)
16 (2.51)
5 (0.78)
24 (21–29)
8 (7–9)
0 (0–2)
560 (49.87)
510 (45.41)
32 (2.85)
21 (1.87)
25 (21–30)
7.75 (6–9)
0 (0–2)
0.617†
<0.001†
FU = follow-up.
Boldface type indicates statistical significance.
† Mann-Whitney U-test.
‡ Fisher’s exact test.
* Levels 1 and 2 compared with levels 3 and 4, chi-square test.
§ Chi-square test.
Pain
Each patient’s pain level was assessed using a self-administered, self-reported visual analog scale (VAS) before
and after surgery (Fig. 2). Preoperative pain was significantly higher in women (median 8, IQR 7–9) than in men
(p < 0.001, Mann-Whitney U-test; Table 1). Both men and
women had a significant reduction in pain after surgery (p
< 0.001, Wilcoxon test).
Levels of Surgery
Overall, 40.5% of patients underwent 1-level surgery,
34.3% 2-level, 21.9% 3-level, and 3.2% 4-level (Table 1).
Fusion
Fusion was assessed with lateral radiographs of the cervical spine during follow-up visits and was recorded when
it occurred. A fusion was considered solid when osseous
trabeculae were seen to bridge the disc space on the lateral
radiograph30 and there was no motion on standard flexion
and extension lateral spine radiographs. An independent
632
FIG. 1. Age distribution (x-axis, in years) of the cohort (y-axis, number of
patients). Figure is available in color online only.
J Neurosurg Spine Volume 28 • June 2018
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
were nonsmokers and inpatients. Three patients underwent
additional surgery because of nonunion, 1 patient had a
ventral revision, and 2 patients underwent additional posterior fusion. These patients were not double counted in
the study.
Complications
FIG. 2. Comparison of preoperative and postoperative pain levels (xaxis, VAS score) in all patients (y-axis, number of patients). Figure is
available in color online only.
neuroradiologist who is not a coauthor of this study reviewed the radiographs. Computed tomography scanning
of the cervical spine was performed if there were clinical
indicators (i.e., neck pain) of passible underlying nonunion,
when there were radiological signs of pseudarthrosis, or
if radiographic results were inconclusive. Five patients
(0.45%) had nonunion during the follow-up; thus, the fusion rate was 99.56%. Two of these patients were male,
smokers, and outpatients, and 3 (1 female and 2 males)
Complications, including nonunion, occurred in 40
patients (3.6%; Table 2). Seven patients (0.62%) who developed significant temporary swallowing problems postoperatively were included in the complication rate even
though the problem was resolved conservatively during
follow-up. Major complications were defined as any septic,
cardiac, pulmonary, or cerebrovascular complications, as
well as deep vein thrombosis, pulmonary embolism, or a
return to the operating suite.10
Despite these complications, all patients had a significant reduction in preoperative pain after surgery (p <
0.001, Wilcoxon test; Table 2). The most common complication was infection in 11 patients (0.98%), followed by
hematoma in 9 (0.80%), Horner syndrome in 5 (0.45%),
nonunion in 5 (0.45%), lower plate-screw breakage in 2
(0.18%), and screw pullout in 1 (0.09%). The 9 patients
with neck hematomas were returned to the operating
room. Two outpatients had a same-day reoperation for the
hematoma (2-level and 4-level ACDF, respectively), and
TABLE 2. Characteristics of patients with complications following ACDF
Complications
Parameter
No
Yes
Overall
No. of patients
Sex (no. [%])
Male
Female
Risk factor (no. [%])
Diabetes mellitus
Smoking
Median height in inches (IQR)
Median weight in lbs (IQR)
Median BMI (IQR)
Surgical level (no. [%])
1
2
3
4
LOS (no. [%])
Outpatient
Inpatient
Median FU in mos (IQR)
Median preop VAS pain score (IQR)
Median postop VAS pain score (IQR)
1083
40
1123
459 (42.4)
624 (57.6)
26 (65)
14 (35)
485 (43.2)
638 (56.8)
163 (15.0)
375 (34.6)
66.5 (64–69)
187.8 (160–215)
29.9 (26.4–33.9)
9 (22.5)
14 (35)
68 (67–69)
185 (153.7–232)
28.7 (25–33.7)
172 (15.3)
389 (34.6)
67.25 (64–69)
186.4 (160–215)
29.3 (26.3–33.8)
447 (41.3)
375 (34.6)
232 (21.4)
29 (2.7)
8 (20)
11 (27.5)
14 (35)
7 (17.5)
455 (40.5)
386 (34.4)
246 (21.9)
36 (3.2)
537 (49.6)
546 (50.4)
25 (21–30)
8 (6–9)
0 (0–2)
23 (57.5)
17 (42.5)
28 (22–34)
8 (6.8–9)
1 (0–3)
560 (49.9)
563 (50.1)
25 (21–30)
8 (6–9)
0.5 (0–2)
p Value
0.005*
0.186†
>0.990‡
0.265†
0.819†
0.283†
<0.001§
0.339‡
0.026†
0.375†
0.039†
Boldface type indicates statistical significance.
* Chi-square test.
† Mann-Whitney U-test.
‡ Fisher’s exact test.
§ Levels 1 and 2 compared with levels 3 and 4, chi-square test.
J Neurosurg Spine Volume 28 • June 2018
633
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
TABLE 3. Patient characteristics according to LOS
Parameter
No. of patients
Median age in yrs (IQR)
Risk factor (no. [%])
Diabetes mellitus
Smoking
Median height in inches (IQR)
Median weight in lbs (IQR)
Median BMI (IQR)
Surgical level (no. [%])
1
2
3
4
Median FU in mos (IQR)
Median preop VAS pain score (IQR)
Median postop VAS pain score (IQR)
Outpatient (same-day discharge) Inpatient (overnight stay)
560
47.5 (41–55)
563
53 (46–62)
63 (11.3)
211 (37.7)
67 (63–70)
185.6 (158.8–216)
29.7 (26.4–33.7)
209 (37.1)
188 (33.4)
136 (24.2)
30 (5.3)
24 (21–29)
7 (6–8)
0 (0–2)
p Value
1123
<0.001
109 (19.4)
178 (31.6)
66 (64–69)
188.5 (160–213.3)
29.9 (26.2–34.1)
246 (43.9)
198 (35.4)
110 (19.6)
6 (1.1)
26 (22–30)
8 (7–9)
0 (0–2)
Overall
172 (15.3)
<0.001†
389 (34.6)
0.501†
66.5 (64–69)
0.381‡
187 (160–215)
0.928‡
29.8 (26.3–33.8) 0.686‡
<0.001*
455 (40.5)
386 (34.4)
246 (21.9)
36 (3.2)
25 (21–30)
0.001‡
7.5 (6–9)
<0.001‡
0 (0–2)
0.713‡
Boldface type indicates statistical significance.
† Fisher’s exact test.
‡ Mann-Whitney U-test.
* Levels 1 and 2 compared with levels 3 and 4, chi-square test.
3 others (3-level, 3-level, and 2-level ACDF, respectively)
were operated on 3, 6, and 6 days after the initial surgery,
respectively. Outpatients with neck hematomas were not
counted as inpatients in our analysis. Four inpatients developed postoperative hematomas (3-level, 3-level, 1-level,
and 4-level ACDF, respectively). They were operated on 1,
4, 6, and 7 days after the initial surgery.
Overall, complications occurred in 1.8% of patients
who underwent 1-level surgery, 2.8% who had 2-level surgery, 5.7% who had 3-level surgery, and 19.4% with 4-level
surgery. Significantly more complications occurred in patients who had 3- or 4-level surgery (p < 0.001, chi-square
test; Table 2). Patients with complications had significantly greater postoperative pain (median VAS score 1, IQR
0–3; p = 0.039, Mann-Whitney U-test).
tient group was older (53 vs 47.5 years, p < 0.001). Significantly more men remained in the hospital for 2 or more
nights (p = 0.010, chi-square test). The 2 groups showed
no differences in height, weight, or BMI. Younger patients
went home the same day (p < 0.001, Mann-Whitney Utest) more often than the older patients. The older patients
having surgery on 1–3 levels stayed in the hospital significantly longer (p < 0.001, chi-square test). Those having
4-level surgery showed no significant differences in age
according to the LOS.
Smoking did not affect the LOS after surgery. There was
a higher rate of diabetes mellitus in the inpatient group. Of
the 172 patients with diabetes (15.3% of the overall group),
109 (63.4% of all patients with diabetes) stayed in the hospital significantly longer (p < 0.001, Fisher’s exact test).
Inpatient and Outpatient Characteristics and Outcome
Comparisons
Length of Stay
A total of 560 patients (49.9%) were discharged home
on the same day (Table 3). Of the remaining 563 patients
(50.1%), 510 (90.6%) remained in the hospital for only 1
night and 96.27% left the hospital within 3 days. Only 21
patients stayed in the hospital 3 nights or more. Patients
were kept in the hospital for medical reasons. The 2 longest LOSs for the inpatients were 10 days (infection) and
18 days (postural hypotension).
Levels of Surgery
General Patient Characteristics
The general characteristics of both groups are shown
in Table 3. There were significant differences in baseline
characteristics and comorbidities between outpatients and
inpatients. Because of the Medicare mandate, the inpa634
The number of fused levels differed between the inpatients and outpatients. Among the inpatients, 209 (37.1%)
underwent 1-level surgery, 188 (33.4%) had 2-level surgery,
136 (24.2%) had 3-level surgery, and 30 (5.3%) had 4-level
surgery.
In the outpatient group, 1-level surgery was the most
common (246 patients [43.9%]). Level C5–6 was the most
common surgical site. Two-level surgery was performed
in 198 patients (35.4%), 3-level surgery in 110 (19.6%), and
4-level surgery in 6 (1.1%).
One- and 2-level surgeries were performed significantly
more often in the outpatient setting, whereas 3- and 4-level
surgeries were performed more often as inpatient procedures (p < 0.001; Figs. 3–6).
Pain
Preoperative pain in the inpatient group was signifi-
J Neurosurg Spine Volume 28 • June 2018
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
FIG. 3. Age distribution (in years, x-axis) for patients (number, y-axis)
who underwent 1-level surgery, according to hospital LOS. Overnight =
overnight stay; Same Day = same-day discharge. Figure is available in
color online only.
cantly lower on the VAS scale than that in the outpatients
(p < 0.001). In both groups, pain was significantly reduced
after surgery (p < 0.001, Wilcoxon test) with no significant
differences between the groups.
Complications
The complication rate was 4.1% in the outpatient group
and 3.0% among the inpatients. There was no statistically
significant difference between these 2 groups (p = 0.339;
Fig. 7). Significantly more complications occurred in patients having 3- or 4-level surgery than in those having
1- or 2-level surgery (p < 0.001, chi-square test). Following
1- and 2-level surgeries, outpatients had more complications than the inpatients, whereas after 3-level surgery inpatients had significantly more complications. Four-level
surgery patients showed no difference in the number of
complications between inpatient and outpatient groups (p
= 0.044). A total of 1.76% of patients who had undergone
1-level surgery and 2.85% of patients who had undergone
2-level surgery experienced complications. Nine patients
had neck hematomas (5 outpatients and 4 inpatients).
Reoperations
FIG. 5. Age distribution (in years, x-axis) for patients (number, y-axis)
who underwent 3-level surgery, according to hospital LOS. Figure is
available in color online only.
11 patients had adjacent-segment disease below the ACDF
level.
Costs
To minimize the reimbursement collection bias, we
compared data for the year 2015, including only commercial insurance carriers. Data were obtained from the chief
financial officers of the outpatient and inpatient institutions
separately. The average facility reimbursement collections
for commercial insurance ACDF procedures were calculated by dividing total commercial insurance reimbursements for 2015 ACDF cases by the number of cases done
that year. These reimbursements were for the operating
room, instrumentation, anesthesia (excluding physician
fees and facility costs), observation/hospital room, imaging, and pharmacy expenses. This calculation was done
both for inpatient and for outpatient institutions, and the
results were compared.
In the outpatient setting, the average reimbursement for
treatment of an individual patient was $18,095. In the inpatient setting, the average reimbursement per patient was
$24,492. The average difference in commercial insurance
reimbursement was $6397 in favor of the outpatient group.
In other words, reimbursements for the outpatient group
were 74% of those for the inpatient group.
A total of 27 patients (2%) were reoperated on during
the follow-up for adjacent-segment disease. Those surgeries were not double counted as primary procedures.
Eleven patients underwent posterior surgery, and 16 underwent anterior surgery. Sixteen patients had adjacentsegment disease above the level of the initial ACDF, and
After the senior author joined the practice (2003) and
after the inauguration of the outpatient surgery center
(2005), the total number of ACDF surgeries, including
the outpatient cases, increased until 2007 and then re-
FIG. 4. Age distribution (in years, x-axis) for patients (number, y-axis)
who underwent 2-level surgery, according to hospital LOS. Figure is
available in color online only.
FIG. 6. Age distribution (in years, x-axis) for patients (number, y-axis)
who underwent 4-level surgery, according to hospital LOS. Figure is
available in color online only.
Distribution of Cases: Timeline
J Neurosurg Spine Volume 28 • June 2018
635
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
FIG. 7. Distribution of complications (number, y-axis) according to LOS.
Figure is available in color online only.
mained relatively stable (after 2009) in terms of both the
absolute number of cases done per year and the inpatient/
outpatient ratio (Fig. 8).
Discussion
To our knowledge, this is the first retrospective singlesurgeon, single-institution study of patients who had undergone ACDF in which the outcomes were compared
between outpatient (same-day discharge) and inpatient
(overnight stay) surgery. This is also the only study to
evaluate clinical outcomes (pain reduction), radiological
outcomes (fusion), and complication rates between the
2 groups. Furthermore, this is the first study to compare
costs for both inpatient and outpatient procedures. Finally,
this study establishes for the first time the safety of performing 3-level ACDF as an outpatient procedure.
In a literature review of PubMed, MEDLINE, and
the Cochrane databases using the keywords “inpatient
ACDF” and “outpatient ACDF,” we identified a total of
12 peer-reviewed articles that compared different outcome
parameters between inpatient and outpatient ACDF.1,10,13,16,
18, 20,21,25,29,32,34,36
Four of these papers were multicenter propensity score–adjusted retrospective or prospective cohort
studies of the NSQIP database.10,13,18,21 Five studies were
retrospective; 1 was prospective. Two studies were retrospective analyses of the National (Nationwide) Inpatient
Sample (NIS) and/or the inpatient and ambulatory databases of 4 states (California, Florida, New Jersey, and New
York). A summary of these studies is featured in Table 4.
In the study by Villavicencio and colleagues, the outpatient data were analyzed retrospectively and compared
with a historical cohort developed from a meta-analysis.36
When we exclude the 4 cohort studies of the NSQIP database10,13,18,21 and the study of Purger et al.,25 our study is
second to that of Adamson and associates in number of
patients and is the only single-surgeon, single-institution
study on ACDF to date. The studies by Silvers and colleagues29 and Liu and associates16 had fewer than 110 patients each, which makes their results difficult to compare
with the results of our study. The studies of Stieber et al.32
and Trahan et al.34—which compared complication rates
only between inpatient and outpatient ACDF—were in636
FIG. 8. Distribution of inpatients and outpatients in the 2003–2016 time
period. Figure is available in color online only.
cluded in our literature review, although these studies also
had fewer than 120 patients each, which again makes comparison with our study difficult.
Inpatient and Outpatient Characteristics and Risk Factors
In our study, the inpatient group was older (53 vs 47.5
years, p < 0.001), and there were no differences in BMI
between the outpatient and inpatient groups. This finding
was comparable to those in most other studies, although
our inpatient group was a bit younger than the inpatient
group in the study by Adamson and colleagues (53 vs 56
years).1 The inpatient group in their study was older than
the outpatient group, as was true in other studies.10,13,16 In a
multicenter study by McGirt and associates, the inpatient
group was older and consisted of more males and more patients with comorbidities, such as diabetes,21 which is consistent with our results. Although we found no differences
between our inpatient and outpatient groups according to
sex, significantly more male patients stayed in the hospital
for 2 or more nights. The reason for this remains unclear.
A possible explanation is that significantly more men were
smokers. Furthermore, according to anthropometric measurements, the men were heavier, although there was no
significant difference in BMI. Current data from the literature show that male sex portends a better ACDF outcome,
relating this finding to greater muscle strength and endurance.22 In a recent study, female sex was identified as one
of the factors contributing to an increased LOS following
ACDF.2 The retrospective nature of that study, given its
low complication rate, does not exclude the possibility of
a confounding bias when it comes to influence of sex on
outcome. Unlike other studies, we did not analyze propensity scores to account for all of the differences that may
have served as potential confounders. But because of our
single-institution, single-surgeon study design and the fact
that there were no differences in sex, smoking, and BMI
between the inpatient and outpatient groups, we can state
that these parameters had very little or no effect on the
outcome.
J Neurosurg Spine Volume 28 • June 2018
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
TABLE 4. Literature studies comparing inpatient and outpatient ACDF procedures
Analysis of Outcome Parameters
Authors &
Year
Silvers et
al., 1996
Stieber et
al., 2005
Villavicencio et al.,
2007
Liu et al.,
2009
Trahan et
al., 2011
Study Type
Surgical
Levels
No. of Surgeons
Prospective
Not specified (>1) 1 & 2
Retrospective
Not specified (>1) 1 & 2
Retrospective
Multiple
1 & 2*
Retrospective
2
1
Retrospective
Multiple (surgeon 1 & 2
& supervised
residents)
Multiple
1
No. of Patients
Reduced
Pain
Fusion
Complication Rate
109 patients: 53 inpatients, 56 outpatients
90 patients: 60 inpatients, 30 outpatients
739 patients: 633
inpatients,† 106
outpatients
109 patients: 64 inpatients, 45 outpatients
117 patients: 58 inpatients, 59 outpatients
Yes
No
Inpatient 2%, outpatient 2%
No
No
No
No
Inpatient 13%, outpatient
10%
Inpatient 0.95%, outpatient
3.8%
Yes
No
Inpatient 3.7%, outpatient 0%
No
No
Inpatient 0%, outpatient 1.4%
2914 patients: 597
outpatients, 2317
inpatients
No
No
Inpatient 2.9%, outpatient
1.3%
Multiple
All levels w/ 7288 patients: 6120
inpatients, 1168
median
outpatients
1.25 ± 0.5
No
No
Inpatient morbidity 1.4%,
outpatient morbidity 3.1%
Multiple
1
6940 patients: 5162
inpatients, 1778
outpatients
No
No
Inpatient 2.5%, outpatient
1.2%
Multiple
1&2
22,006 patients: 4759
outpatients, 17,247
inpatients
No
No
Inpatient 3.94%, outpatient
1.47%
Multiple
1&2
1484 patients: 1000
outpatients, 484
inpatients
No
No
Purger et
Retrospective study
al., 2017
using data from the
HCUP SID, SASD,
& SEDD in FL, NY,
& CA
Multiple
Not specified 50,131 patients: 3135
ambulatory, 46,996
inpatient
No
No
McClelland Retrospective cohort
study using the NIS
et al.,
from 2001–2012 &
2017
the HCUP SASD for
NJ for 2003–2012
Multiple
1&2
No
No
30-day readmission: inpatient
2.9% vs outpatient 1.8%;
90-day readmission: inpatient 1.5% vs outpatient
1.3%; 90-day reoperation (same site) 1-level:
1 inpatient (0.4%), 1
outpatient (0.2%); 90-day
reoperation (same site)
2-level: 1 inpatient (0.5%),
1 outpatient (0.3%)
51 (1.6%) outpatients
readmitted, 5 (0.2%)
underwent reoperation;
1778 (3.8%) inpatients
readmitted, 200 (0.4%)
underwent reoperation
14 postop complications
assessed in propensity
score–matched analysis
of NIS & NJ SASD to
examine impact of ACDF;
no specified complication
rate
Martin et
Multicenter propensity
al., 2014
score–adjusted retrospective cohort study
of NSQIP database
McGirt et
Multicenter propensity
al., 2015
score–adjusted retrospective cohort study
of NSQIP database
Khanna et Multicenter propensity
al., 2017
score–adjusted retrospective cohort study
of NSQIP database
Fu et al.,
Retrospective cohort
2017
study of prospectively
collected data from
NSQIP database
Adamson Retrospective
et al.,
2016
257,398 inpatients, 2016
outpatients; propensity score matching
used to adjust analysis: 10,080 patients:
8064 inpatients, 2016
outpatients
CONTINUED ON PAGE 638 »
J Neurosurg Spine Volume 28 • June 2018
637
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
» CONTINUED FROM PAGE 637
TABLE 4. Literature studies comparing inpatient and outpatient ACDF procedures
Analysis of Outcome Parameters
Authors &
Year
Present
study,
2018
Study Type
Retrospective
No. of Surgeons
Single
Surgical
Levels
1–4
No. of Patients
1123 patients: 560
outpatients, 563
inpatients
Reduced
Pain
Fusion
Yes
Yes
Complication Rate
Overall: 3.21%; outpatient
4.15%, inpatient 3.17%‡
CA = California; FL = Florida; HCUP = Healthcare Cost and Utilization Project; NJ = New Jersey; NY = New York; SASD = State Ambulatory Surgery and Services
Databases; SEDD = State Emergency Department Databases; SID = State Inpatient Databases.
All studies had level III evidence.
* Ninety-six percent of patients had 1 or 2 surgical levels.
† Inpatients were a meta-analysis–derived comparison group.
‡ No statistical significance between the inpatient and outpatient groups, p = 0.424.
A recent study by Martin and associates analyzed risk
factors that influence the outcome of inpatient and outpatient single-level ACDF.18 An ASA physical status class
III or IV, current dialysis, current corticosteroid use, recent sepsis, and operative times longer than 120 minutes
were each independent risk factors for complications in
the multivariate analysis. After propensity score matching
to control for comorbidities, there were no significant differences in the complication rates between inpatients and
outpatients, and outpatient treatment was not a risk factor
for complications in the multivariate analysis. This result
is consistent with the findings of McGirt and associates,
who showed that an ASA class III or higher, chronic steroid use, hypertension, and male sex were risk factors for
postdischarge complications.21
Smoking did not affect the complication rate, nonunion
rate, or LOS after surgery in our study. Luszczyk and colleagues found no statistically significant difference in fusion status between smokers and nonsmokers who had undergone a single-level ACDF with allograft and a locked
anterior cervical plate.17
Diabetes is one of the most common comorbidities
in patients undergoing ACDF.1 In our study, there was a
higher rate of diabetes mellitus in the inpatients, and the
patients with diabetes stayed in the hospital significantly
longer. This finding is consistent with a recent retrospective analysis of prospectively collected data from the
NSQIP, which associated insulin-dependent diabetes with
increased total LOS.23
Levels of Surgery
In the outpatient group, significantly more patients had
1- and 2-level surgeries, whereas inpatients underwent 3and 4-level procedures more often. This was an expected
observation corroborating data in the literature. Fu and
colleagues showed that outpatients are less likely to undergo multilevel surgery.10 A recent multicenter meta-analysis
of outpatient ACDF revealed that nearly two-thirds of outpatients underwent single-level fusion with virtually none
undergoing ACDF at 3 or more levels, as well as an overall
complication rate of 1.8%.19 Our study is the first to establish 3-level surgery as a standard procedure in the outpatient setting given that one-fifth of our outpatient cohort
638
had 3-level surgery; all other studies have concentrated on
1- and 2-level surgeries.
Fusion
Nonunion occurred in 5 of our patients (0.45%). Two
outpatients and 3 inpatients had pseudarthrosis. Two were
treated with bone stimulators, and fusion occurred over 6
and 8 months’ time, respectively, and was confirmed on
CT scanning. Three patients underwent reoperation. The
use of anterior cervical plating has been suggested to increase arthrodesis rates and decrease subsidence, making
allograft an attractive option. For instrumented 1-level fusions, Samartzis and associates reported 100% arthrodesis
with intervertebral cage allograft compared with 90.3%
arthrodesis with autograft, although the difference between the two was not statistically significant.26 In another
study, the fusion rate was 100% in the allograft group and
90.3% in the autograft group, again with no statistically
significant difference (p > 0.05).15 The largest meta-analysis so far showed a fusion rate of 92.1% for ACDF.9 The
cases in studies by Silvers and associates29 and Liu and
colleagues16 were noninstrumented, and Adamson and colleagues did not specify which graft was used for fusion.1
Fraser and Härtl showed that, regardless of the number of
levels fused, the use of an anterior cervical plate system
significantly increases the fusion rate.9 Our experience of
a high rate of fusion utilizing bone allografts corroborates
this finding.
Complications
In our series, complications occurred in 3.6% of patients, with no significant difference in the complication
rate between outpatients (4.1%) and inpatients (3.0%).
Our complication rates are slightly higher than those in
some previous studies comparing the outcomes of inpatient versus outpatient ACDF, yet they are lower than the
complication rates reported by Fountas et al.7 and Stieber
et al.32 There are 2 main reasons for this. First is our inclusion of nonunion (long-term complication) and temporary
swallowing difficulties as complications. Excluding these
complications would lower our rate of permanent complications to 2.5%. Second, previous studies analyzed either
1- or 2-level ACDF or mostly 1- and 2-level ACDF with
J Neurosurg Spine Volume 28 • June 2018
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
only a small number of 3-level surgeries. Nonetheless, in
our series, the rate of complications in both settings was
relatively low and no deaths were observed. In addition,
we were fortunate not to experience any vascular, esophageal, nerve, or dural injuries.
In our study, 21.9% had 3-level surgery and the results
showed that the complication rate is generally higher for 3and 4-level surgery than for 1-level and 2-level surgery (p
< 0.001, chi-square test). Furthermore, patients undergoing
3-level ACDF had significantly more complications in the
outpatient setting than in the inpatient setting, whereas the
findings were opposite for 4-level ACDF. The reliability of
these differences is questionable, however, given the small
number of cases. In the literature, multilevel ACDF has
been shown to have an increased complication rate, and
the rate rises with the number of segments fused.14,35
Overall, 1.8% of patients who had undergone 1-level
surgery and 2.8% of those who had undergone 2-level surgery experienced complications. Outpatient 1-level surgery
had a complication rate of 2%, and 1- and 2-level outpatient surgery together had a rate of 3.16%, which is comparable to the findings of McGirt and associates.21 For 1- and
2-level surgery, 3 studies of the NSQIP database showed a
lower rate of postoperative complications in the outpatient
cohort,10,13,21 while the study by Adamson and associates,1
like ours, showed that all 90-day surgical morbidity was
similar between outpatient and inpatient cohorts for 1- and
2-level ACDF. A recent 12-year nationwide inpatient analysis and 10-year single-state outpatient analysis of more
than 250,000 total patients who had undergone 1- and
2-level surgery indicated that outpatient ACDF may yield
fewer perioperative complications than inpatient ACDF,
including durotomy, hematoma, paraplegia, respiratory
complications, and anemia.20 This same study reported
that ACDF performed on an outpatient basis was 19% less
likely to result in an intraoperative durotomy and 86% less
likely to result in a postoperative hematoma or seroma.
These findings may be attributable to potential reporting
bias between inpatient and outpatient centers given that
hospitals (unlike ambulatory centers) are incentivized to
report comorbidities and complications.20 Another potential explanation may be the significantly greater proportion
of Medicare patients in the inpatient group since Medicare
patients are more likely to have medical problems and associated comorbidities and to require longer hospitalizations.20,37
A major factor contributing to the reluctance of surgeons
to perform ACDF in the outpatient setting is the potential
complication of airway compromise as a result of airway
swelling or postoperative hematoma. But this complication is almost always recognizable within the first 4 hours
after surgery, well within the time frame of perioperative
observation in the ambulatory surgery setting.21 Our study
included 9 patients with postoperative hematomas who
underwent revision, and there were no permanent deficits.
Close monitoring of outpatients for 6 hours postoperatively and then close daily follow-up via phone interview
for 4 postoperative days allowed for the detection of all
patients with this complication in a timely fashion. Fountas
and associates,7 who analyzed the complications of ACDF,
postulated that the development of isolated postoperative
dysphagia was the most common complication (9.5%), followed by postoperative hematoma (5.6%), symptomatic
recurrent laryngeal nerve palsy (3.1%), dural penetration
(0.5%), esophageal perforation (0.3%), Horner syndrome
(0.1%), instrumentation back-out (0.1%), and superficial
wound infection (0.1%).
Our rates for the 2 most common complications reported
in the literature were significantly lower, with only 0.8% of
patients developing hematoma and 0.62% developing swallowing difficulties. Wound infection (0.98%) and Horner
syndrome (0.45%) occurred at a slightly higher rate. The
slight increase in wound infections could be a result of the
associated comorbidities, which make patients more prone
to developing infection. Because of this potential, we now
universally apply vancomycin 1 hour before surgery in an
attempt to decrease or eliminate this complication. Compared with the results of Adamson and associates,1 we had
a greater number of neck hematomas, which needed revision surgery (3 vs 9), and more infections (3 vs 11), but
none of our patients needed exploratory surgery to correct
the swallowing difficulty (as opposed to 16 patients in the
Adamson cohort). Silvers et al.29 and McGirt et al.21 did
not report neck hematoma as a complication, whereas Liu
et al.16 described it as a complication in 1 patient in their
cohort. Khanna et al.13 reported 0.5% of inpatients with
bleeding as a postoperative complication, as well as 0.6%
of inpatients and 0.3% of outpatients with surgical site infection. In the 30-day morbidity analysis by Martin and
associates,18 there were 5 deaths. Furthermore, the same
study described, among other complications, postoperative
surgical site infection in 0.48% of patients, unplanned intubation in 0.4%, and wound complications in 0.6%, with
a reoperation rate of 1.2% in the first 30 days following
ACDF.18 In the study by Khanna and colleagues, 0.2% of
inpatients and 0.1% of outpatients died.13
Several groups of investigators have concluded that
ACDF can be safely performed in the outpatient setting
with a sufficient postoperative observation period of up to
4 hours.11,16,27 Our protocol further increases postoperative
observation to 6 hours, adding an additional layer of safety.
Numerous studies have verified the safety of outpatient
ACDF surgery.3,4,6,19,24,28,33,34,36 The procedure performed in
an ambulatory setting is not inferior to inpatient surgery
in terms of mortality, 30-day emergency department visit
rates, 30-day readmission rates, and 30-day reoperation
rates and is less costly than inpatient ACDF in terms of
actual costs and 90-day bundled charges.25 Nonetheless,
a recent risk-complication analysis of studies on cervical
spine surgery performed in ambulatory surgery centers has
revealed that at least some of these studies demonstrated
an inherent conflict of interest and did not report major
morbidity and mortality rates for outpatient procedures in
a nonbiased way, which must be considered.23
A study by Silvers and associates comparing outpatient
versus inpatient ACDF in 103 consecutive patients showed
equal complication rates (2%) in both groups.29 Similarly,
a study by Liu and colleagues involving 109 patients did
not show any significant differences in outcomes between
outpatient and inpatient groups.16 McGirt and associates
also verified the safety of outpatient ACDF, with those
who had undergone outpatient ACDF having 58% lower
J Neurosurg Spine Volume 28 • June 2018
639
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
odds of experiencing major morbidity and 80% lower odds
of a return to the operating room within 30 days.21 Villavicencio and associates evaluated outpatient and 23-hour admissions for ACDF and plating (ACDF+P) and compared
their numbers to those in a historical cohort treated as inpatients, finding no difference in the complication rates.36
Another study showed that among 1-level and 2-level
ACDF cases, the rate of any postoperative complication
was significantly lower in the outpatient group than in the
inpatient cohort.10 Our study strongly supports the findings
of other authors who assert that the risk of complications
is not higher in the outpatient setting than in the inpatient
setting.
Costs
The increased use of outpatient ACDF instead of inpatient ACDF represented a way to decrease payers’ costs by
more than $100 million in 1996.29 Adjusting for the utilization of ACDF in 2012, the cost savings may be as high
as $400 million annually.21 While an acute care episode
is the largest contributor to the cost of spine surgery, the
greatest variability in cost occurs with the wide range in
complication rates, hospital readmissions, and reoperations
during the post–acute care period.21 The recent study of
Purger et al.25 revealed that actual costs associated with
the initial operation, as well as 90-day cumulative charges
(charges associated with the initial surgery plus all emergency department visits, hospital readmissions, and revisits
to ambulatory surgery centers), were significantly lower for
outpatient ACDF than for inpatient ACDF. Overall charges
were significantly lower for ambulatory ACDF ($33,362.51
vs $74,667.04, p < 0.0001).25
Limits of This Study
The limitations of this study include its retrospective
design, our inability to exclude its selection bias, and the
relatively short mean follow-up period (slightly more than 2
years). This single-surgeon experience may limit the ability to generalize results to the entire population undergoing
ACDF. Furthermore, patients with cervical radiculopathy
cannot be differentiated from those with myelopathy, and
outcomes can differ in these 2 patient populations.21
Conclusions
Anterior cervical discectomy and fusion is safe to perform on an outpatient basis for 1 or 2 levels, with a high
rate of successful fusion and pain reduction, a low complication rate, and no deaths. Three-level ACDF can also
be performed as a standard procedure in an outpatient surgery center with close monitoring. Close follow-up should
be done for at least 6 hours postoperatively with the drain
in position. Additional consideration needs to be given to
patients with comorbidities, such as diabetes mellitus. To
decrease the cost of care, surgeons can safely consider
performing ACDF in an ambulatory surgery center. The
comparable clinical and radiological outcomes and the
same complication rates for inpatients and outpatients may
favor performing ACDF procedures in the outpatient setting, whenever medically and logistically possible, to lower
costs.
640
Acknowledgments
We thank Ms. Julie Yamamoto, MA, for editing this manuscript, Ms. Kristina Kralik for statistical expertise, and Mr. Andrew
J. Gienapp for copy editing, preparation of the manuscript and
figures for publishing, and publication assistance.
References
1. Adamson T, Godil SS, Mehrlich M, Mendenhall S, Asher
AL, McGirt MJ: Anterior cervical discectomy and fusion in
the outpatient ambulatory surgery setting compared with the
inpatient hospital setting: analysis of 1000 consecutive cases.
J Neurosurg Spine 24:878–884, 2016
2. Arnold PM, Rice LR, Anderson KK, McMahon JK, Connelly
LM, Norvell DC: Factors affecting hospital length of stay following anterior cervical discectomy and fusion. Evid Based
Spine Care J 2:11–18, 2011
3. Baird EO, Egorova NN, McAnany SJ, Qureshi SA, Hecht
AC, Cho SK: National trends in outpatient surgical treatment of degenerative cervical spine disease. Global Spine J
4:143–150, 2014
4. Ban D, Liu Y, Cao T, Feng S: Safety of outpatient anterior
cervical discectomy and fusion: a systematic review and
meta-analysis. Eur J Med Res 21:34, 2016
5. Cloward RB: The anterior approach for removal of ruptured
cervical disks. 1958. J Neurosurg Spine 6:496–511, 2007
6. Erickson M, Fites BS, Thieken MT, McGee AW: Outpatient
anterior cervical discectomy and fusion. Am J Orthop
36:429–432, 2007
7. Fountas KN, Kapsalaki EZ, Nikolakakos LG, Smisson HF,
Johnston KW, Grigorian AA, et al: Anterior cervical discectomy and fusion associated complications. Spine (Phila Pa
1976) 32:2310–2317, 2007
8. Fowler SB, Anthony-Phillips P, Mehta D, Liebman K:
Health-related quality of life in patients undergoing anterior
cervical discectomy fusion. J Neurosci Nurs 37:97–100,
2005
9. Fraser JF, Härtl R: Anterior approaches to fusion of the
cervical spine: a metaanalysis of fusion rates. J Neurosurg
Spine 6:298–303, 2007
10. Fu MC, Gruskay JA, Samuel AM, Sheha ED, Derman PB,
Iyer S, et al: Outpatient anterior cervical discectomy and
fusion is associated with fewer short-term complications
in one-and two-level cases: a propensity-adjusted analysis.
Spine (Phila Pa 1976) 42:1044–1049, 2017
11. Garringer SM, Sasso RC: Safety of anterior cervical discectomy and fusion performed as outpatient surgery. J Spinal
Disord Tech 23:439–443, 2010
12. Helseth Ø, Lied B, Halvorsen CM, Ekseth K, Helseth E: Outpatient cervical and lumbar spine surgery is feasible and safe:
a consecutive single center series of 1449 patients. Neurosurgery 76:728–738, 2015
13. Khanna R, Kim RB, Lam SK, Cybulski GR, Smith ZA, Dahdaleh NS: Comparing short-term complications of inpatient
versus outpatient single-level anterior cervical discectomy
and fusion: an analysis of 6940 patients using the ACSNSQIP database. Clin Spine Surg [epub ahead of print], 2017
14. Koller H, Hempfing A, Ferraris L, Maier O, Hitzl W, MetzStavenhagen P: 4- and 5-level anterior fusions of the cervical
spine: review of literature and clinical results. Eur Spine J
16:2055–2071, 2007
15. Leven D, Cho SK: Pseudarthrosis of the cervical spine: risk
factors, diagnosis and management. Asian Spine J 10:776–
786, 2016
16. Liu JT, Briner RP, Friedman JA: Comparison of inpatient vs.
outpatient anterior cervical discectomy and fusion: a retrospective case series. BMC Surg 9:3, 2009
17. Luszczyk M, Smith JS, Fischgrund JS, Ludwig SC, Sasso RC,
Shaffrey CI, et al: Does smoking have an impact on fusion
J Neurosurg Spine Volume 28 • June 2018
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC
J. Mullins et al.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
rate in single-level anterior cervical discectomy and fusion
with allograft and rigid plate fixation? Clinical article. J Neurosurg Spine 19:527–531, 2013
Martin CT, Pugely AJ, Gao Y, Mendoza-Lattes S: Thirtyday morbidity after single-level anterior cervical discectomy
and fusion: identification of risk factors and emphasis on
the safety of outpatient procedures. J Bone Joint Surg Am
96:1288–1294, 2014
McClelland S III, Oren JH, Protopsaltis TS, Passias PG:
Outpatient anterior cervical discectomy and fusion: A metaanalysis. J Clin Neurosci 34:166–168, 2016
McClelland S III, Passias PG, Errico TJ, Bess RS, Protopsaltis TS: Inpatient versus outpatient anterior cervical discectomy and fusion: a perioperative complication analysis of
259,414 patients from the Healthcare Cost and Utilization
Project databases. Int J Spine Surg 11:11, 2017
McGirt MJ, Godil SS, Asher AL, Parker SL, Devin CJ: Quality analysis of anterior cervical discectomy and fusion in the
outpatient versus inpatient setting: analysis of 7288 patients
from the NSQIP database. Neurosurg Focus 39(6):E9, 2015
Peolsson A, Peolsson M: Predictive factors for long-term
outcome of anterior cervical decompression and fusion: a
multivariate data analysis. Eur Spine J 17:406–414, 2008
Phan K, Kim JS, Lee N, Kothari P, Cho SK: Impact of insulin
dependence on perioperative outcomes following anterior
cervical discectomy and fusion. Spine (Phila Pa 1976)
42:456–464, 2017
Pugely AJ, Martin CT, Gao Y, Mendoza-Lattes SA: Outpatient surgery reduces short-term complications in lumbar
discectomy: an analysis of 4310 patients from the ACSNSQIP database. Spine (Phila Pa 1976) 38:264–271, 2013
Purger DA, Pendharkar AV, Ho AL, Sussman ES, Yang L,
Desai M, et al: Outpatient vs inpatient anterior cervical discectomy and fusion: a population-level analysis of outcomes
and cost. Neurosurgery [epub ahead of print], 2017
Samartzis D, Shen FH, Goldberg EJ, An HS: Is autograft the
gold standard in achieving radiographic fusion in one-level
anterior cervical discectomy and fusion with rigid anterior
plate fixation? Spine (Phila Pa 1976) 30:1756–1761, 2005
Sasso RC, Ruggiero RA Jr, Reilly TM, Hall PV: Early reconstruction failures after multilevel cervical corpectomy. Spine
(Phila Pa 1976) 28:140–142, 2003
Sheperd CS, Young WF: Instrumented outpatient anterior
cervical discectomy and fusion: is it safe? Int Surg 97:86–
89, 2012
Silvers HR, Lewis PJ, Suddaby LS, Asch HL, Clabeaux DE,
Blumenson LE: Day surgery for cervical microdiscectomy: is
it safe and effective? J Spinal Disord 9:287–293, 1996
Singh P, Kumar A, Shekhawat V: Comparative analysis of interbody cages versus tricortical graft with anterior plate fixa-
31.
32.
33.
34.
35.
36.
37.
tion for anterior cervical discectomy and fusion in degenerative cervical disc disease. J Clin Diagn Res 10:RC05–RC08,
2016
Smith GW, Robinson RA: The treatment of certain cervicalspine disorders by anterior removal of the intervertebral disc
and interbody fusion. J Bone Joint Surg Am 40-A:607–624,
1958
Stieber JR, Brown K, Donald GD, Cohen JD: Anterior cervical decompression and fusion with plate fixation as an outpatient procedure. Spine J 5:503–507, 2005
Tally WC, Tarabadkar S, Kovalenko BV: Safety and feasibility of outpatient ACDF in an ambulatory setting: a retrospective chart review. Int J Spine Surg 7:e84–e87, 2013
Trahan J, Abramova MV, Richter EO, Steck JC: Feasibility
of anterior cervical discectomy and fusion as an outpatient
procedure. World Neurosurg 75:145–148, 43–44, 2011
Veeravagu A, Cole T, Jiang B, Ratliff JK: Revision rates and
complication incidence in single- and multilevel anterior
cervical discectomy and fusion procedures: an administrative
database study. Spine J 14:1125–1131, 2014
Villavicencio AT, Pushchak E, Burneikiene S, Thramann JJ:
The safety of instrumented outpatient anterior cervical discectomy and fusion. Spine J 7:148–153, 2007
Waits SA, Reames BN, Sheetz KH, Englesbe MJ, Campbell
DA Jr: Anticipating the effects of Medicaid expansion on
surgical care. JAMA Surg 149:745–747, 2014
Disclosures
No funding was used for this study. Mr. Mullins, Dr. Pojskić, and
Dr. Arnautović have no financial relationships to disclose. Dr.
Boop serves as a consultant for Medtronic.
Author Contributions
Conception and design: Arnautović, Pojskić, Boop. Acquisition of
data: Arnautović, Mullins, Pojskić. Analysis and interpretation of
data: Arnautović, Pojskić, Boop. Drafting the article: Arnautović,
Mullins, Pojskić. Critically revising the article: Arnautović,
Pojskić, Boop. Reviewed submitted version of manuscript:
Arnautović, Pojskić, Boop. Approved the final version of the manuscript on behalf of all authors: Arnautović. Statistical analysis:
Arnautović, Mullins, Pojskić.
Correspondence
Kenan Arnautović: Semmes Murphey Neurologic & Spine Institute, University of Tennessee Health Science Center, Memphis,
TN. kenanarnaut@yahoo.com.
J Neurosurg Spine Volume 28 • June 2018
641
Unauthenticated | Downloaded 05/18/22 03:44 AM UTC