ASERNIP S
Australian Safety
and Efficacy
Register of New
Interventional
Procedures –
Surgical
Consumer Summary
Arthroscopic Subacromial Decompression using the Holmium:YAG laser
(Adapted from the report of the Review Group for consumer use by Ms M. Boult)
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ASERNIP-S has undertaken a systematic review of the medical literature concerning treatment of
impingement syndrome with arthroscopic subacromial decompression using the Holmium:YAG
laser. The purpose of the review was to ascertain the safety and effectiveness of this surgical
procedure. In addition to the findings of the review and the recommendations made by ASERNIP-S
to the Royal Australasian College of Surgeons, some background information on shoulder
impingement has been provided.
What is impingement syndrome?
Impingement syndrome is a condition where the space between two of the bones in the shoulder
gets narrower resulting in a “pinching” of the tissues within the space. This causes pain and
stiffness for the sufferer.
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The shoulder is a complicated part of the body made up of bones, muscles, joints, ligaments,
tendons and a bursa. When these parts are working properly they allow the greatest range of
movement of any body part. However injury or wear and tear to parts of the shoulder can result in
pain or stiffness with movement.
There are three bones which make up the shoulder:
·
shoulder blade (scapula)
·
upper arm bone (humerus) and
·
collarbone (clavicle).
The top-most point of the shoulder blade is also called the acromion, and the smooth, concave,
undersurface together with the ligament from the acromion to the coracoid makes up the
coracoacromial arch. The latter name derives from a bony projection on the outer edge of the
scapula called the coracoid process. Impingement or “pinching” occurs to the tissues beneath this
bony and ligamentous arch in the subacromial space, i.e. in the space beneath the acromion and
coracoacromial ligament.
The shoulder has two joints
·
the acromioclavicular (AC) joint which is located between the
collarbone (clavicle) and the acromion and
·
the shoulder joint, properly called the glenohumeral joint.
The shoulder joint is a ball-and-socket type joint where the ball is the
rounded end of the upper arm bone and the socket is the dish-shaped part of the shoulder blade.
Around the shoulder joint socket is a
capsule or envelope attaching the
two bones together, the thickenings
of which are called ligaments.
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The bones and joints of the shoulder are held in place by muscles, tendons and ligaments. There are
four major muscles of the shoulder. The tendons that are connected to these muscles blend with the
capsule surrounding the shoulder joint to form a structure known as the rotator cuff. The rotator cuff
muscles and tendons control our ability to raise the arm from the side and help maintain the stability
of the shoulder joint.
Several important ligaments attach the shoulder bones to each other and provide stability within the
shoulder. For example the capsule which surrounds the shoulder joint has a group of ligaments that
connect the “ball” at the end of the upper arm bone to the “socket” of the shoulder joint on the
shoulder blade.
Between the immobile acromion and the mobile rotator cuff
tendons there is a bursa which allows gliding between these
structures.
When the arm is raised there needs to be sufficient space for the tendons of the rotator cuff to slide
under the acromion. By definition impingement syndrome may involve the “pinching” of one or
more of the shoulder bursa, the four cuff muscles, a shoulder muscle tendon and a card-like biceps
tendon, all of which are located under the coracoacromial arch. The “pinching” is caused by a
narrowing of the subacromial space.
What causes impingement syndrome?
Typical causes of damage leading to impingement syndrome include:
·
prolonged work at or above shoulder level
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·
repetitive and/or heavy forceful motions such as throwing / tennis
·
prolonged exposure to heavy handheld vibrating tools such as jackhammers
·
normal wear and tear due to aging
·
variations that people are born with in the structure of the bones or AC joint
·
scarring from accidents or operations
·
instability of the shoulder joint
How do you know if you have impingement syndrome?
The diagnosis of a shoulder problem can be difficult due to the number of possible shoulder injuries
and the similarity between them. Traditionally the changes that occur in the shoulder as a
consequence of impingement syndrome have been divided into three stages of increasing severity.
q
Stage 1 is characterised by an inflammatory reaction resulting in excessive accumulation of
fluid or swelling of the tissues under the arch (i.e. bursa and / or cuff tendons).
q
Stage 2 is reached when there is thickening and scarring of the tendons and bursa.
q
Stage 3 is indicated by tendon failure and bony changes.
Early symptoms of impingement syndrome include an aching shoulder and pain when the arm is
raised out from the side of the body or in front of the body. Most patients have difficulties sleeping
due to pain, especially when they roll over onto the affected shoulder. As the process continues
through the three stages, pain and discomfort increase and the joint may feel stiffer. Sometimes a
“catching” feeling happens when the arm is lowered. The symptoms of impingement syndrome
become worse with each stage and include:
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Stage 1
·
Pain that is gradual in onset
·
Pain that follows strenuous activity
·
Pain made worse by overhead activity or direct pressure
Stage 2
·
Aching discomfort that may interfere with sleep and work, and may progress and interfere
with activities of daily life.
Stage 3
·
Prolonged periods of pain, especially at night
·
Stiffness and weakness in the shoulder
There are various means that your doctor will use to establish (diagnose) whether you have
impingement syndrome. One is described as the impingement test. In this the doctor moves the
shoulder in a way that is known to cause pain. Anaesthetic is then injected into the shoulder below
the acromion. The movement of the shoulder is then repeated. If the pain caused by the movement
has been eliminated the test is positive and impingement syndrome is suspected. Additional tests
include X-rays (radiographs) which can help determine possible causes of impingement such as
changes to the bone (e.g. spurs), however stage 1 impingement will not show up on an X-ray.
Ultrasound can also be used as a diagnostic test. Radiologists can use ultrasound to see whether the
catching and pinching of tissues is coinciding with the shoulder pain. MRI (magnetic resonance
imaging) can also be useful to determine whether there are any tears in the rotator cuff. In addition
to these diagnostic tests your doctor will examine your history and conduct a thorough physical
examination. There are several other conditions that resemble impingement syndrome including
frozen shoulder, arthritis and joint degeneration.
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What treatment options are available?
Once a diagnosis of impingement syndrome has been made, treatment will depend on the severity
of the symptoms and may include patient education, physical therapy and medical management.
Together this is known as “conservative treatment”. If this treatment has failed, following a period
of 6-12 months, surgery may be considered appropriate if the individual is experiencing severe pain
or unable to function normally.
The aim of the surgery is to increase the space between the acromion and the rotator cuff tendons
(i.e. arthroscopic subacromial decompression). This involves removing any bony spurs found under
the acromion that are rubbing on the rotator cuff tendons and bursa. Part of the acromion and its
lining may also be removed (acromioplasty) to enable the tendons to move without rubbing on the
bottom of the acromion. The subacromial bursa is also removed (bursectomy) from the subacromial
space and the ligament that attaches to the coracoid process and acromion is peeled away from the
bottom surface of the acromion (coracoacromial ligament resection).
There are two main surgical ways in which subacromial decompression may be done. The operation
can be performed via a large cut (incision), however since the 1980’s the tendency in shoulder
surgery has been towards smaller incisions. Smaller incisions have been made possible by the
introduction of a special optical device called an arthroscope. A procedure called arthroscopic
subacromial decompression (ASD) enables impingement syndrome to be relieved using a smaller
incision. During ASD surgical instruments are inserted through small holes in the skin, and the
bursectomy, coracoacromial ligament resection and acromioplasty are done whilst the surgeon
views the site through the arthroscope. The advantage of this technique is that the patient usually
recovers more quickly from the surgery and requires less screening. By viewing the joint directly
the diagnosis of the underlying problem may be better than that obtained from other imaging
techniques such as X-rays or from physical examination of the patients shoulder. arthroscopic
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subacromial decompression is now regarded as a well-established and popular technique for the
treatment of impingement syndrome.
Arthroscopic subacromial decompression using a Holmium:YAG laser
A modification to the technique of arthroscopic subacromial decompression has been introduced to
surgery during the last ten years. Instead of using mechanical instruments to perform the
acromioplasty, coracoacromial ligament resection and bursectomy procedures, these functions have
been performed using a laser. A laser is a device that generates an intense beam of light which is
powerful enough to cut, separate and destroy living tissue but in a very precise, controlled way. In
surgery there are several types of laser in use such as the neodymium:yttrium-aluminuim-garnet
(Nd:YAG) laser, the argon laser, the carbon dioxide laser and the holmium:yttrium-aluminiumgarnet (Ho:YAG) laser. The lasers differ according to the type of light they emit. In surgery the
effect of the light is to heat the tissue, which results in it melting, or burning. The Ho:YAG laser has
been found to be particularly suitable for orthopaedic procedures. The reported advantage of using
the Ho:YAG laser for subacromial decompression is its ability to reduce pain and swelling after the
operation and to prevent bleeding from small blood vessels.
Is arthroscopic subacromial decompression using a Ho:YAG laser safe?
Safety
There has been insufficient information published in the scientific journals to draw any firm
conclusions about the safety of the procedure. Up to the end of 1999 there were only eight articles
in the major medical literature that referred to the procedure. None of these reported any major
problems with safety. The complications reported included a painful portal area (i.e. the site at
which an instrument was inserted through the skin), and minor problems with the laser equipment
(handpiece failed during the operation).
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Efficacy
As mentioned above, the lack of supporting information means that no firm conclusions can be
drawn from the literature in terms of the effectiveness of the procedure. In one report of 200
patients, three patients required a second operation, as the first operation had not adequately
decompressed the subacromial space. Five other patients required a different type of operation,
indicating that a wrong diagnosis from the symptoms had been made. One article questioned
whether the laser was effective at cutting bone, however, this apparently referred to an earlier model
of the laser.
Recommendation to the Royal Australasian College of Surgeons
A review group that comprised surgeons from the field of orthopaedic surgery and surgeons from
different specialties, in addition to a researcher and the ASERNIP-S Surgical Director assessed the
evidence available on arthroscopic subacromial decompression using the Ho:YAG laser.
The group recommended that The safety and/or efficacy of the procedure cannot be determined at the present time due to
an incomplete and /or poor evidence base. The procedure should only be used with caution
and it is also recommended that further research be conducted to establish safety and/or
efficacy. In order to strengthen the evidence base regarding the procedure it was
recommended that a controlled clinical trial; ideally with random allocation to an
intervention and control group, be conducted.
This classification was given due to the small number of studies identified and the poor quality of
the information contained in all studies concerning arthroscopic subacromial decompression.
The Royal Australasian College of Surgeons recognises that it may not always be possible to
undertake a controlled clinical trial. Under such circumstances, it is recommended that at the very
least, data be contributed to an audit for further assessment, in collaboration with ASERNIP-S, until
such time as a controlled clinical trial is undertaken.
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Acknowledgments
Collins Dictionary of Medicine, Robert M Youngson, Harper Collins Publishers, Glasgow
Churchill Livingstone Pocket Medical Dictionary, 13th Edition Ed Nancy Roper Edinburgh
Scotland.
Some excellent anatomical drawings and animations of the shoulder are available online from the
Medical Multimedia Group: www.medicalmultimediagroup.com/opectoc.html. All the diagrams
contained in this article were derived from this source.
Key words: laser shoulder surgery, laser shoulder arthroscopy
June 2000
Important Note:
The information contained in this report is a distillation of the best available
evidence located at the time the searches were completed as stated in the
protocol. Please consult with your medical practitioner if you have further
questions relating to the information provided, as the clinical context may
vary from patient to patient.
For further information about ASERNIP-S
Contact Professor Guy Maddern, ASERNIP-S Surgical Director, PO Box 688, North Adelaide, SA
5006, ph. (08) 82391144, fax (08) 82391244, or visit the website (www.surgeons.org/asernip-s).
If you would like to provide feedback on this consumer summary, please contact us at
[email protected] .
ASERNIP-S is a programme of the Royal Australasian College of Surgeons (RACS).
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Glossary
Acromial arch: the smooth concave undersurface of the acromion and the coracoacromial
ligament. It provides a strong ceiling for the shoulder joint along which the cuff tendons must glide
during all shoulder movements.
Acromion: the top or roof of the shoulder blade. The acromion is joined to the tip of the collar bone
in the acromioclavicular joint and is the outer extremity of the shoulder blade.
Arthroscopic subacromial decompression: an arthroscopic operation to relieve impingement
syndrome. The surgery is done through small incisions and uses an arthroscope to view within the
joint. The procedure involves removing the subacromial bursa, removing some of the acromion and
resectioning the coracoacromial ligament.
Bones: the main structural material in the body.
Bursa: a small fibrous sac lined with a membrane that secretes a lubricating fluid. Bursae are found
in many parts of the body, they are protective and friction-reducing structures which occur around
joints and in areas where tendons pass over bones.
Capsule: an outer covering made up of a group of ligaments. In the shoulder joint the ligaments
join the humerus to the socket of the shoulder joint on the scapula.
Coracoacromial arch: see acromial arch.
Coracoid process: a finger-like bony process on the outer edge of the shoulder blade, which points
forward.
Deltoid muscle: a large, triangular-shaped muscle of the shoulder sometimes called the ‘shoulder
pad’.
Impingement syndrome: a condition where the space between two of the bones in the shoulder
gets narrower resulting in a “pinching” of the tissues within the space.
Joints: a junction between bones, where movement may or may not be possible. A synovial joint
such as the shoulder is freely moveable and has lubricated bearing surfaces. Synovial joints are
enclosed in capsules and are reinforced by internal and external ligaments. The shoulder joint
capsule is known as the rotator cuff.
Ligaments: bundles of a tough, fibrous, elastic protein called collagen that connect bones to bones.
Muscles: a tissue made up of individual cells which can shorten and thicken, the result of which is
to cause movement in the body. Muscles are connected to bones by tendons, and bones move when
tendons are pulled by muscle action.
Rotator cuff: the structure around the shoulder joint which consists of the tendons of four muscles
blended with the capsule of the joint.
Subacromial: beneath the acromion.
Tendons: a strong band of collagen fibres that joins muscle to bone or cartilage and transmits the
force of muscle contraction to cause movement.
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