Anatomy of the Shoulder
The two main bones of the shoulder are the humerus and the scapula (shoulder
blade). The joint cavity is cushioned by articular cartilage covering
the head of the humerus and face of the glenoid. The scapula extends up
and around the shoulder joint at the rear to form a roof called the acromion,
and around the shoulder joint at the front to form the coracoid process.
The end of the scapula, called the glenoid, meets the head of the humerus
to form a glenohumeral cavity that acts as a flexible ball-and-socket
joint. The joint is stabilized by a ring of fibrous cartilage surrounding
the glenoid called the labrum.
Ligaments connect the bones of the shoulder, and tendons join the bones
to surrounding muscles. The biceps tendon attaches the biceps muscle to
the shoulder and helps to stabilize the joint. Four short muscles originate
on the scapula and pass around the shoulder where their tendons fuse together
to form the rotator cuff.
All of these components of your shoulder, along with the muscles of your
upper body, work together to manage the stress your shoulder receives
as you extend, flex, lift and throw.
Rotator Cuff Disease / Impingement Syndrome Frequently Asked Questions
What is the rotator cuff in the shoulder?
The rotator cuff is a group of flat tendons which fuse together and surround
the front, back, and top of the shoulder joint like a cuff on a shirt
sleeve. These tendons are connected individually to short, but very important,
muscles that originate from the scapula. When the muscles contract, they
pull on the rotator cuff tendon, causing the shoulder to rotate upward,
inward, or outward, hence the name "rotator cuff."
What is impingement syndrome?
The uppermost tendon of the rotator cuff, the supraspinatus tendon, passes
beneath the bone on the top of the shoulder, called the acromion. In some
people, the space between the undersurface of the acromion and the top
of the humeral head is quite narrow. The rotator cuff tendon and the adherent
bursa, or lubricating tissue, can therefore be pinched when the arm is
raised into a forward position. With repetitive impingement, the tendons
and bursa can become inflamed and swollen and cause the painful situation
known as "chronic impingement syndrome."
How does impingement syndrome relate to rotator cuff disease?
When the rotator cuff tendon and its overlying bursa become inflamed and
swollen with impingement syndrome, the tendon may begin to break down
near its attachment on the humerus bone. With continued impingement, the
tendon is progressively damaged, and finally, may tear completely away
from the bone.
Why do some people develop impingement and rotator cuff disease when others do not?
There are many factors that may predispose one person to impingement and
rotator cuff problems. The most common is the shape and thickness of the
acromion (the bone forming the roof of the shoulder). If the acromion
has a bone spur on the front edge, it is more likely to impinge on the
rotator cuff when the arm is elevated forward. Activities which involve
forward elevation of the arm may put an individual at higher risk for
rotator cuff injury. Sometimes the muscles of the shoulder may become
imbalanced by injury or atrophy, and imbalance can cause the shoulder
to move forward with certain activities which again may cause impingement.
Other than impingement, what else can cause rotator cuff damage?
In young, athletic individuals, injury to the rotator cuff can occur with
repetitive throwing, overhead racquet sports, or swimming. This type of
injury results from repetitive stretching of the rotator cuff during the
follow-through phase of the activity. The tear that occurs is not caused
by impingement, but more by a joint imbalance. This may be associated
with looseness in the front of the shoulder caused by a weakness in the
What kind of symptoms does a patient have when the rotator cuff is injured?
The most common complaint is aching located in the top and front of the
shoulder, or on the outer side of the upper arm (deltoid area). The pain
is usually increased when the arm is lifted to the overhead position.
Frequently, the pain seems to be worse at night, and often interrupts
sleep. Depending on the severity of the injury, there may also be weakness
in the arm and with some complete rotator cuff tears the arm cannot be
lifted in the forward or outward direction at all.
How is the diagnosis of rotator cuff disease proven?
The diagnosis of rotator cuff tendon disease includes a careful history
taken and reviewed by the physician, an x-ray to visualize the anatomy
of the bones of the shoulder, specifically looking for acromial spur,
and a physical examination. Atrophy may be present, along with weakness,
if the rotator cuff tendons are injured, and special impingement tests
can suggest that impingement syndrome is involved. An MRI (magnetic resonance
imaging) scan frequently gives the final proof of the status of the rotator
cuff tendon. Although none of these tests is guaranteed accurate, most
rotator cuff injuries can be diagnosed using this combination of exams.
What is the initial treatment for rotator cuff disease and impingement?
If minor impingement or rotator cuff tendinitis is diagnosed, a period
of rest coupled with medicines taken by mouth, and physical therapy will
frequently decrease the inflammation and restore the tone to the atrophied
muscles. Activities causing the pain should be slowly resumed only when
the pain is gone. Sometimes a cortisone injection into the bursal space
above the rotator cuff tendon is helpful to relieve swelling and inflammation.
Application of ice to the tender area three or four times a day for 15
minutes is also helpful.
What is the second line of treatment if the rotator cuff pain and weakness persist?
If there is a thickened acromion or acromial bone spur causing impingement,
it can be removed with a burr using arthroscopic visualization. This procedure
can often be performed on an outpatient basis, and at the same time, any
minor damage and fraying to the rotator cuff tendon and scarred bursal
tissue can be removed. Often this will completely cure the impingement
and prevent progressive rotator cuff injury.
If the rotator cuff is already torn, what are the options?
When the tendon of the rotator cuff has a complete tear, the tendon often
must be repaired using surgical techniques. The choice of surgery, of
course, depends on the severity of the symptoms, the health of the patient,
and the functional requirements for that shoulder. In young working individuals,
repair of the tendon is most often suggested. In some older individuals
who do not require significant overhead lifting ability, surgical repair
may not be as important. If chronic pain and disability are present at
any age, consideration for repair of the rotator cuff should be given.
What will happen if the rotator cuff is not repaired?
In some situations, the bursa overlying the rotator cuff may form a patch
to close the defect in the tendon. Although this is not true tendon healing,
it may decrease the pain to an acceptable level. If the tendon edges become
fragmented and severely worn, and the muscle contracts and atrophies,
repair at that point may not be possible. Sometimes in this situation,
the only beneficial surgical procedure would be an arthroscopic operation
to remove bone spurs and fragments of torn tissue that catch when the
arm is rotated. This certainly will not restore normal power or strength
to the shoulder, but often will relieve pain.
How is a major injury to the rotator cuff tendon repaired surgically?
The arthroscope is extremely helpful when repairing rotator cuff tendons,
but sometimes it is necessary to add a "mini-open" procedure
if the tendon is completely torn. Using the arthroscope at the beginning
of the case allows visualization of the interior of the joint to facilitate
trimming and removal of fragments of torn cuff tendon and biceps tendon.
The next step utilizes the arthroscope to visualize the spur and thickened
ligament beneath the acromial bone, while they are removed with miniature
cutting and grinding instruments. If it is necessary to suture a rotator
cuff tear which has pulled off the bone, a two-inch incision can be made
directly over the tear that has been visualized and localized using the
arthroscope. The deltoid muscle fibers can be spread apart so that strong
stitches can attach the rotator cuff tendon back to the bone. If the tear
is minimally retracted, small suture screw anchors may be used arthroscopically or open.
How is my shoulder treated after surgery?
In a minor operation for impingement, the shoulder is placed in a simple
sling. If a full thickness tear of the rotator cuff was present and repaired,
then the shoulder will be supported by an UltraSling or a SCOI postoperative
brace. The brace is very helpful because it will allow exercise of the
elbow, wrist, and hand at all times, and places the arm in a position
that promotes better blood circulation and relieves stress on the repaired
rotator cuff tissues. In addition, the shoulder can be exercised in the
brace much easier than when it is at the side in an immobilizer.
What is the rehabilitation program after rotator cuff surgery?
Depending on the type of surgery performed, the program will allow a period
of time for healing of the soft tissues followed by time to regain range
of motion and then strengthen the shoulder muscles, but particularly the
rotator cuff. In minor tendinitis and impingement syndrome, the program
takes approximately two to three months. If the rotator cuff tendon has
been completely torn, it may take six months or more before the atrophied
muscles can resume their function and the range of motion of the arm is
restored. Frequently, pain relief is much quicker and return to daily
activities is often possible by two to three months.
How successful is rotator cuff surgery?
Again, every case is unique. In the young, healthy person with a minor
rotator cuff impingement, surgery is predictably successful. As the injury
becomes more severe, such as with a large bone spur and fragmentation
of the tendon, then a perfect result cannot be expected. Since it is necessary
to trim back the unhealthy tendon before reattaching it to the bone, a
decreased range of motion of the shoulder will often result. Despite this,
pain relief and return of strength are usually well worth the minor decreased
mobility. The final outcome often depends on the willingness and ability
of an individual patient to work on their postoperative physical therapy program.
Shoulder instability represents a spectrum of disorders, the successful
management of which requires a correct diagnosis and treatment. The boundaries
of this spectrum are represented by a subluxation event (a partial dislocation
which spontaneously reduces), to a complete dislocation which often requires
anesthesia to reduce the shoulder. The majority of instabilities are traumatic
in nature and the ball of the shoulder is unstable toward the front of
the shoulder. It is this type of shoulder instability which we will concentrate on here.
In order for a shoulder to dislocate, the very important and delicate balance
of soft tissues (ligaments, capsule and tendons) around the shoulder must
become damaged. These damaged tissues often don't heal properly and
the shoulder can develop recurrent dislocations and/or pain with certain
types of activities.
The older a patient is at the time of initial injury the lower the chances
are for developing recurrent instability. Patients under the age of 20
with traumatic dislocations have a substantially higher rate of recurrence
(greater than 90%).
It is for this reason we have become more aggressive in recent years in
recommending early repair for this group of patients. We believe early
repair reduces the likelihood of further injuring the shoulder with additional
episodes of dislocation.
The treatment for recurrent shoulder instability is usually surgical. This
surgery is aimed at repairing the damaged capsule and ligaments directly.
This procedure can be done arthroscopically as an outpatient. The surgery
is performed with a miniature lighted telescope and small instruments
introduced into the shoulder joint through hollow cannulas. Advanced miniature
anchors with suture attached are inserted precisely into the socket of
the shoulder, and the torn ligaments are reattached to the socket. Complete
healing from this procedure takes approximately 4-6 months.
Calcium Deposits in the Shoulder
Calcium deposits around the shoulder are a fairly common occurrence. Frequently
they do not cause problems, but if they increase in size or become inflamed,
then very severe pain may result. This collection of questions and answers
is intended to explain this common shoulder problem and describe the methods
we recommend for treatment in different situations.
What is the cause of calcium deposits around the shoulder?
In most situations, there is no known cause for calcium deposits. Many
people ask if their diet should be changed to reduce calcium intake. This
should never be used as a form of treatment, since a normal balanced diet
with a calcium supplement up to 1000mg a day is healthy in a normal patient,
particularly senior citizens and post-menopausal females.
Who most commonly gets calcium deposits?
Calcium deposits occur most frequently in females between 35 and 65 years
of age, but may occur in males as well.
Do all calcium deposits cause problems?
Many calcium deposits are present for years without causing any symptoms.
Only when the deposit becomes large enough to pinch between the bones
when the shoulder is elevated, does it cause pain. Sometimes smaller deposits
cause pain if they become acutely inflamed, especially when the calcium
salts leak from the lesion into the sensitive bursal tissues.
Does a calcium deposit damage my shoulder?
Some calcium deposits can cause erosion with the destruction of a portion
of the rotator cuff tendon. Most calcium deposits remain on the outside
of the rotator cuff tendon in the bursa and only cause problems because
of their pain and catching.
Is the calcium deposit hard like a rock?
Most early calcium deposits are very soft like toothpaste, but sometimes
after being present for a long period of time, they do dry up and become
chalk-like, sometimes even turning to bone.
What is the best treatment for a calcium deposit?
When a calcium deposit becomes acutely inflamed, either because it ruptures
and leaks calcium salts into the bursa, or because it pinches the bursa
or rotator cuff, the symptoms can be quite severe. The acute inflammation
can be treated with localized ice packs and rest in a sling, but oral
anti-inflammatory medications are also helpful. A cortisone injection
directly into the area of the calcium deposit may give relief within a
few hours, when without it the acute severe pain may last for several days.
Do calcium deposits need removal?
If a patient has two or three recurrent episodes of painful symptoms in
the shoulder, or if the calcium deposit appears on x-ray to be enlarging,
then it may be appropriate to consider arthroscopic surgery to remove it.
What is involved in arthroscopic surgery to remove calcium?
The surgery is done in the outpatient department under a general anesthesia.
There is no pain at all during the operation and afterwards a mild aching
sensation is usually present for a few days until the skin puncture sites
heal. If the calcium erodes a hole in the rotator cuff, then a decompression
is necessary (removing a portion of the overhanging bone arthroscopically)
and this will cause a little more discomfort for a few days.
Will calcification return once it is removed?
It is incredibly rare for a calcification return in the same shoulder once
it has been removed.
Can there be any permanent damage caused by calcification?
Yes. A long term calcification may cause pressure on the rotator cuff tendon
which can damage portions of the tendon permanently.
The AC (Acromioclavicular) Joint
What is the AC Joint in the shoulder?
The top of the wing bone or scapula is the acromion. The joint formed where
the acromion connects to the collar bone or clavicle is the AC joint.
Usually there is a protuberance or bump in this area, which can be quite
large in some people normally. This joint, like most joints in the body,
has a cartilage disk or meniscus inside and the ends of the bones are
covered with cartilage. The joint is held together by a capsule, and the
clavicle is held in the proper position by two heavy ligaments called
How is the AC Joint usually injured?
The AC joint is injured most often when one falls directly on the point
of the shoulder. The trauma will separate the acromion away from the clavicle,
causing a sprain or a true AC joint dislocation. In a mild injury, the
ligaments which support the AC joint are simply stretched (Grade I), but
with more severe injury, the ligaments can partially tear (Grade II) or
completely tear (Grade III). In the most severe injury, the end of the
clavicle protrudes beneath the skin and is visible as a prominent bump.
How is an AC Joint separation diagnosed?
Most often the clinical exam will demonstrate tenderness or bruising around
the top of the shoulder near the AC joint, and the suspected diagnosis
can be confirmed using an x-ray, which compares the injured side with
the patient's other joint.
What is the proper treatment for a sprained AC Joint?
When a joint is first sprained, conservative treatment is certainly the
best. Applying ice directly to the point of the shoulder is helpful to
inhibit swelling and relieve pain. The arm can be supported with a sling
which also relieves some of the weight from the shoulder. Gentle motion
of the arm can be allowed to prevent stiffness, and exercise putty is
very helpful to improve function of the elbow, wrist, and hand, but any
attempts at vigorous shoulder mobilization early on will probably lead
to more swelling and pain.
How long does it take for a shoulder separation to heal?
Depending on how severe the injury is, it may heal adequately in two to
three weeks. In severe cases, the shoulder may not heal without surgery.
When and why is surgery necessary for AC Joint separations?
Usually surgery is reserved for those cases where there is residual pain
or unacceptable deformity in the joint after several months of conservative
treatment. The pain can occur with direct pressure on the joint, such
as with straps from underwear or work clothing. Sometimes there will be
catching, clicking, or pain with overhead activities, such as lifting,
throwing, or reaching. Finally, in some people with very thin skin and
very little muscular and soft tissue padding above their shoulders, the
prominent clavicle after the separation may be considered unattractive,
since the shoulder can appear to be unbalanced.
Are there other causes of AC Joint pain and disability?
Arthritis can occur as an isolated event in the AC joint, causing stiffness,
aching, and sometimes swelling. Another condition called DCO, or distal
clavicle osteolysis, gives a similar picture, usually in young people
who lift heavy weights. This is called "Weightlifter's Shoulder."
What type of surgery can repair AC Joint problems?
The simplest type of surgery for AC joint injury involves resection or
removal of the end of the clavicle using arthroscopic (mini-surgical)
techniques (called a Mumford procedure). If the joint becomes painful
because of DCO (weightlifter's shoulder) or arthritis, or the separation
is only minor, this technique can be very satisfactory. When the joint
is severely displaced, then a more complex procedure is needed to restore
the position of the clavicle. Usually this operation, called a Weaver-Dunn
procedure, is done using a two-inch incision over the joint. The end of
the clavicle is removed, and ligament is transferred from the underside
of the acromion into the cut end of the clavicle to replace the ligaments
torn during the dislocation. Soon an arthroscopic procedure should be
available to restore the position of the joint, but at this point, only
open surgery techniques are available.
What is the postoperative treatment and rehabilitation?
Postoperatively, treatment depends on the type of surgery performed. Usually,
when the Mumford procedure is performed using arthroscopic techniques,
the arm can be treated with a sling. Bathing is allowed in three days'
time, and elbow, wrist, and hand exercises are begun immediately. Lifting
is limited for three weeks, but following that, progressive exercise and
motion activities proceed as the symptoms allow.
When a Weaver-Dunn procedure (rebuilding of the torn ligaments) is needed,
approximately two or three weeks is added to the immobilization time before
motion exercises are begun. This time allows the ligament to heal. Otherwise,
the exercise program is the same as that for the Mumford procedure above.
The Biceps Tendon
What is the biceps tendon?
The biceps tendon is a long cord-like structure which is located in the
front of the shoulder. It originates from the top of the shoulder socket
(the glenoid) and exits the joint through a bony trough (the biceps groove).
Below the shoulder, this tendon becomes the long head of the biceps muscle.
The short head of the biceps is a continuation of the conjoined tendon
which originates from a bony hook (the coracoid) at the front of the shoulder
blade. Thus the biceps muscle, which functions to bend the elbow and rotate
the forearm, has two anchor points in the shoulder region.
Who get biceps tendon injuries?
In general, these injuries occur more frequently as we become older. As
we age, our tendons lose their elasticity and slowly become stiffer and
more "brittle." The blood supply which nourishes the tendon
also diminishes with age. The "degenerative" processes may be
more pronounced in sedentary individuals, but may be lessened with proper
and regular exercise. The well-conditioned individual, however, is not
immune from biceps tendon injuries as over-training can also harm an otherwise
How do biceps tendon injuries occur?
As mentioned above, age, inactivity, or over-activity can weaken a tendon
which may lead to injury due to the decreased ability to endure repetitive
motions and sudden loads. Because of its location, from a direct blow
to the front of the shoulder, some individuals develop bone spurs in their
biceps grooves or under the top of their shoulder blades (the acromion)
which can lead to wear and tear of their tendons. A less frequent injury
is a dislocation of the biceps tendon from its groove. This is usually
seen in combination with a tear of the subscapularis tendon or the rotator
cuff tendon which normally help hold the biceps tendon in it groove. The
biceps tendon can also be injured at its attachment site on top of the
glenoid. This usually involves an avulsion, where the tendon is pulled
off the bone and rendered unstable.
What happens to the tendon when it is injured?
If the tendon or its sheath (which encases the tendon) is irritated, it
becomes inflamed, resulting in pain and swelling. This condition is called
"tendinitis." Mild injuries can also result in microscopic tearing
of individual tendon fibers. As the severity of an injury increases, larger
tears can occur to the point where the tendon is partially torn or even
completely ruptured. If a rupture occurs, the long head will usually fall
distally toward the elbow. Biceps muscle function usually remains nearly
normal because of its dual attachment proximally.
How are biceps tendon injuries treated?
Initially, rest, ice, and gentle anti-inflammatory medications are all
that is usually needed. Sometimes an injection with a strong anti-inflammatory
medication such as cortisone is needed to control the pain and swelling.
Severe cases which fail to improve may require surgical treatment.
What does surgery involve?
Surgical treatment depends on the nature and extent of damage to the tendon.
If only a small portion of the tendon is damaged, a simple arthroscopic
shaving (debridement) of the torn fibers may be all that is needed. If
a significant portion is involved, a biceps tenodesis may need to be performed.
This is done by arthroscopically removing the torn tendon stump from inside
the shoulder joint and then, through a small skin incision, attaching
the remaining tendon to the bone in the upper arm (humerus). If the biceps
tendon is completely ruptured, causing the muscle to bulge in the upper
arm, a tenodesis can be done only if the distal portion remains near the
top of the shoulder. A tenodesis is not done if the tendon slides too
far distally because doing so would require unacceptably large incisions.
If the tendon has been partially avulsed from its origin on the top of
the glenoid (SLAP lesion) it can be arthroscopically reattached using
miniature screws and sutures.
What is the usual course after surgery?
A simple sling is all that is needed for the first few weeks after surgery.
Immediate use of the hand is encouraged, but only for very light objects.
Four to six weeks of healing is required before a gradual return to moderate
or heavy lifting. Desk work and light-duty can usually be resumed within
the first week or two. Return to heavy labor usually takes 2 to 4 months.