Five succinct key points:
-Otolaryngologists are at high risk for ergonomic injury, particularly
in the neck and cervical spine region.
- There is a need to use validated ergonomic assessment tools to
quantify the amount of risk in specific otolaryngology procedures and
identify alternative methods to decrease that risk.
- The physical positioning of the senior author was studied
using the RULA score during two different operative approaches to
tonsillectomy: one using an endoscope and one using direct visualization
without the aid of an endoscope.
- The RULA score for the traditional, non-endoscopic approach was 5,
with a Neck, Trunk, and Leg Score of 6 and a Wrist/Arm score of 1,
demonstrating a high risk and suggesting a need for further
investigation and change. The RULA score for the endoscopic-assisted
approach was 3, with a Neck, Trunk, and Leg score of 4 and a Wrist/Arm
score of 1.
-An endoscopic-assisted approach to tonsillectomy allowed for a lower
RULA score than traditional tonsillectomy. This study suggests that an
endoscopic approach may decrease the potential for musculoskeletal
strain and reduce occupational-related pain and injury seen in
practicing otolaryngologists.
Introduction: Prior research has demonstrated that
otolaryngologists are at high risk for ergonomic injury, particularly in
the neck and cervical spine region, manifesting as stiffness and pain
(1-3). Some otolaryngologists even report the need to stop during
procedures or miss workdays due to the musculoskeletal burden they are
consistently subjected to (3). Therefore, there is a need to use
validated ergonomic assessment tools to quantify the amount of risk in
specific otolaryngology procedures and identify alternative methods to
decrease that risk.
The RULA tool, created by Corlett and McAtamney (1993), is a screening
tool based on observation to assess exposure to energy use due to neck,
trunk, and upper limb posture, muscle use, and forces (4). The
administration of this tool is inexpensive and does not require special
tools or pre-existing skills. Rodman et al. (2020) used the RULA tool to
analyze surgical ergonomics in pediatric otolaryngology. This study
demonstrated that 37% of intraoperative observations had a high
ergonomic risk, while 16% had a very high risk (2). Furthermore, a
recent systematic review and meta-analysis demonstrated the prevalence
of work-related MSK discomfort to be approximately 79% among practicing
otolaryngologists (5). Thus, given the high prevalence of work-related
musculoskeletal discomfort and the unacceptable level of ergonomic risk
for common procedures, analyzing the ergonomic risk of alternative
techniques and new technologies is needed to reduce and lower the risk
of musculoskeletal injury for otolaryngologists.
The tonsillectomy is one of the most frequently performed surgeries by
the otolaryngologist. There are several techniques for tonsillectomy,
but in general, they are performed macroscopically, requiring the
surgeon to look down and flex their cervical spine for the extent of the
procedure. However, an alternative to the macroscopic approach is an
endoscopic-assisted tonsillectomy, either by having an assistant hold
the endoscope or mounted on an endoscope holder. We believe that the
ergonomics of the endoscopic-assisted tonsillectomy technique may reduce
the neck and cervical spine strain of the performing surgeon. Thus, this
study aims to quantitatively evaluate the ergonomics of traditionally
performed tonsillectomy versus an alternative endoscopic-assisted
tonsillectomy. Further, we compare the additional positive and negative
aspects of using the endoscope for tonsillectomy.
Methods: A simulation tonsillectomy was conducted using
a Airsim advance Bronchi 2 manakin for the subject. A zero-degree
Hopkins rod connected to a 4K camera and a Storz video tower was
Endoscopic Assisted tonsillectomy and a Welch Allyn headlight attached
to a xenon light source was used for traditional tonsillectomy. In both
cases an Arthrocare Evac 70 Cobator handpiece was utilized. The physical
positioning of the senior author was studied during simulation of two
different operative approaches to tonsillectomy: one using an endoscope
and one using direct visualization without the aid of an endoscope.
Whole-body postural data was collected and analyzed using the validated
Rapid Upper Limb Assessments (RULA) tool to calculate the risk of
musculoskeletal injuries. To use the RULA tool, the viewer assigns a
numerical rating to the posture of the upper arms, lower arms, and
wrists, which equals Score A, together with the stance of the neck,
trunk, and legs equals score B. The observer then assigns another
numerical rating for extra factors that strain the musculoskeletal
system, such as static loading, repetitive action, and force exertion.
Thus, Score A + muscle use + force scores for group A equals Score C,
and Score B + muscle use + force scores for group B equals Score D.
The numerical ratings are scored and computed to a Grand Score, ranging
from 1 to 7. A RULA score of 1 to 2 is negligible the risk with no
action required, 3 to 4 is low risk with a potential need for change, 5
to 6 is a high risk suggesting a need for further investigation and
change, and 6 or greater is a very high risk with the need for rapid
change (2). The otolaryngologist subject of this simulation study is the
senior author of this project, making it exempt from IRB review.
Results: The RULA score for the traditional,
non-endoscopic approach was 5, with a Neck, Trunk, Leg Score of 6 and a
Wrist/Arm score of 1(Fig1). The RULA score for the endoscopic-assisted
approach was 3, with a Neck, Trunk, Leg score of 4 and a Wrist/Arm score
of 1(Fig2). The difference between the two approaches narrowed down to
the effect on neck positioning (angle decreased from >20
degrees with traditional to nearly 0 degrees with endoscopic) and trunk
positioning (angle reduced from 20-60 degrees with traditional to 0
degrees with endoscopic).
Discussion: Our study demonstrated that the
endoscopic-assisted approach to tonsillectomy allowed for a lower RULA
score, suggesting that there may be potential to reduce the
musculoskeletal strain and injuries induced by repetitive MSD. This
study is the first to utilize the RULA tool to analyze the ergonomic
risk of a traditional tonsillectomy versus an endoscopic approach.
Traditionally, the tonsillectomy is performed macroscopically under the
surgeon’s direct vision, necessitating sustained neck flexion to look
down at the surgical field (6). Rodman et al. found that this procedure
carried a RULA score of 5, which indicates that a procedure has a high
risk of ergonomic injury, and that further investigation and rapid
change are warranted (2). In comparison, the endoscopic-assisted
approach to tonsillectomy allowed for a lower RULA score of 3,
indicating a lower risk of ergonomic injury. Notably, the
endoscopic-assisted approach allows the surgeon is primarily looking up
at a screen, a position that is more neutral than the constant flexion
of the traditional approach. As a result, the difference between the two
approaches narrowed down to the effect on neck positioning, and the
angle decreased from >20 degrees with traditional to nearly
0 degrees with endoscopic.
In addition to the ergonomic issues, the traditional tonsillectomy is an
approach that is often not amenable for other members of the medical
team to have direct visualization due to the small surgical field. In
contrast, the endoscopic-assisted tonsillectomy is an approach that uses
an endoscope for indirect visualization, projecting the surgical field
onto a screen. This alternate approach has been shown to facilitate the
education of tonsillectomy techniques while enabling the surgeon to
operate with comparable, if not enhanced, precision due to the enlarged
view of the operation field (6). Additionally, with the wide-angle of
the endoscopic view compared to that offered by microscopy, it is not
necessary to move the fixed endoscope during the operation.
Despite the decreased ergonomic risk and the proposed educational
advantage, endoscopic-assisted tonsillectomies may carry some
disadvantages, including increased cost per procedure and the need for
an additional set of hands or an endoscope-holder setup. A previous
observational cohort study analyzing the significant expenses for
same-day adenotonsillectomy (T&A) found that the mean cost per T&A was
approximately $1506 with a 95% confidence interval, $1492-$1519 (7).
This study demonstrated that the most significant cost categories
included using the Operating Room (31.9%), Same Day Services such as
anesthesia and pharmacy (28.1%), and OR supplies (15.6%)(7).
Furthermore, a previous study examining the cost difference between the
Endoscopic Stapling Technique for the Treatment of Zenker Diverticulum
vs. the Standard Open-Neck Technique demonstrated that endoscopic
procedures, although maybe shorter in operative time, add increased cost
per procedure when compared to the conventional open approach(8) . This
increased price was attributed to specialized equipment, notably the
EndoGIA endoscopic stapler. Additionally, the costs associated with
reprocessing conventional endoscopes can range between $ 140 and $ 280
per endoscope (9). Thus, utilizing the reusable endoscope for routine,
same day adenotonsillectomy would undoubtedly add to the OR supply
expenses and likely increase the total cost of a procedure.
Nevertheless, a possible strategy to decrease the price per
endoscopic-assisted tonsillectomy procedure maybe be to use single-use
disposable endoscopes. For example, a previous study comparing the Costs
of Reusable Versus Disposable endoscopes in Carpal Tunnel surgery
demonstrated that the disposable equipment was less costly, resulting in
cost savings of $102 (10). Therefore, perhaps using disposable
endoscopes for endoscopic-assisted tonsillectomy may reduce cost.
However, a cost comparison between conventional tonsillectomies versus
endoscopic-assisted tonsillectomies or reusable endoscopes versus
disposable endoscopic-assisted tonsillectomies has yet to be performed
and requires further study.
This study is limited by evaluating the ergonomics of a single surgeon
on a single day. More studies are required to validate and expand on our
findings, by assessing multiple surgeons throughout different stages of
their careers.
Conclusions: Our study demonstrated that the
endoscopic-assisted approach to tonsillectomy allowed for a lower RULA
score than the traditional macroscopic tonsillectomy approach. While
previous research has shown the educational benefits of increased
visualization with an endoscopic procedure, this study suggests that an
endoscopic approach may additionally aid in reducing
occupational-related pain and injury. Though endoscopes may add
considerable cost to tonsillectomies, the rise in low-cost disposable
endoscopes may further promote this surgical technique.