Shoulder

A Patient’s Guide to Artificial Joint Replacement of the Shoulder

Introduction

Shoulder joint replacement surgery (also called shoulder arthroplasty) is not as common as replacement surgeries for the knee or hip joints. Still, when necessary, this operation can effectively ease pain from shoulder arthritis. Most people experience improved shoulder function after this surgery.

This guide will help you understand

• how the shoulder works
• what parts of the shoulder are replaced in surgery
• what to expect after shoulder replacement surgery

Anatomy

What parts make up the shoulder?

The shoulder is made up of three bones: the scapula (shoulder blade), the humerus (upper arm bone), and the clavicle (collarbone).

The rotator cuff connects the humerus to the scapula. The rotator cuff is formed by the tendons of four muscles: the supraspinatus, infraspinatus, teres minor, and subscapularis.

Tendons attach muscles to bones. Muscles move bones by pulling on the tendons. The rotator cuff helps raise and rotate the arm. As the arm is raised, the rotator cuff also keeps the humerus tightly in the socket. A part of the scapula, called the glenoid, makes up the socket of the shoulder. The glenoid is very shallow and flat.

The part of the scapula that connects to the shoulder is called the acromion. A bursa is located between the acromion and the rotator cuff tendons. A bursa is a lubricated sac of tissue that cuts down on the friction between two moving parts. Bursae are located all over the body where tissues must rub against each other. In this case, the bursa protects the acromion and the rotator cuff from grinding against each other.

The humeral head of the shoulder is the ball portion of the joint. The humeral head has several blood vessels, which enter at the base of the articular cartilage. Articular cartilage is the smooth, white material that covers the ends of bones in most joints. Articular cartilage provides a slick, rubbery surface that allows the bones to glide over each other as they move. Cartilage also functions as sort of a shock absorber.

The shoulder joint is surrounded by a watertight sac called the joint capsule. The joint capsule holds fluids that lubricate the joint. The walls of the joint capsule are made up of ligaments. Ligaments are connective tissues that attach bones to bones. The joint capsule has a considerable amount of slack, loose tissue, so that the shoulder is unrestricted as it moves through its large range of motion.

Related Document: A Patient’s Guide to Shoulder Anatomy

Rationale

What conditions lead to shoulder joint replacement?

The most common reason for undergoing shoulder replacement surgery is osteoarthritis. Osteoarthritis is caused by the degeneration of the joint over time, through wear and tear. Osteoarthritis can occur without any injury to the shoulder, but that is uncommon. Because the shoulder is not a weight-bearing joint, it does not suffer as much wear and tear as other joints. Osteoarthritis is more common in the hip and knee.

Most of the time osteoarthritis occurs many years after an injury to the shoulder. For example, a shoulder dislocation can result in an unstable shoulder. The extra movement or repeated dislocation of the unstable joint causes damage to the articular cartilage and other joint tissues. Over time, this damage leads to osteoarthritis.

Osteoarthritis is not the only type of arthritis that affects the shoulder joint. Systemic diseases, such as rheumatoid arthritis, may affect any joint in the body. Whatever the type or cause of the arthritis, the shoulder may become painful and difficult to use. If you and your doctor can’t find ways to control your pain, or if it becomes impossible to use your shoulder for daily tasks, your doctor may recommend shoulder replacement surgery.

Certain types of shoulder fractures can injure the blood vessels of the humeral head. The fracture may heal, but the blood vessels don’t. When the blood vessels are damaged, the humeral head no longer has any blood supply. This condition leads to a condition called aseptic necrosis.

In necrosis, parts of the joint surface actually die. Over time, necrosis of the shoulder joint can lead to arthritis. When fractures affect the humeral head, doctors may recommend a shoulder joint replacement. In some cases, the risk of developing necrosis is so high that it makes sense to replace the humeral head immediately.

In most cases, doctors see shoulder replacement surgery as the last option. Sometimes there is a benefit to delaying shoulder replacement surgery as long as possible. Your doctor will probably want you to try nonsurgical measures to control your pain and improve your shoulder movement, including medications and physical or occupational therapy.

Like any arthritic condition, osteoarthritis of the shoulder may respond to anti-inflammatory medications such as aspirin or ibuprofen. Acetaminophen (Tylenol®) may also be prescribed to ease the pain. Some of the newer medications such as glucosamine and chondroitin sulfate are more commonly prescribed today. They seem to be effective in helping reduce the pain of osteoarthritis in all joints. There are also new injectable medications that lubricate the arthritic joint. These medications have been studied mainly in the knee. It is unclear if they will help the arthritic shoulder.

Physical or occupational therapy may be suggested to help you regain as much of the motion and strength in your shoulder as possible before you undergo surgery.

An injection of cortisone into the shoulder joint may give temporary relief. Cortisone is a powerful anti-inflammatory medication that can ease inflammation and reduce pain, possibly for several months. Most surgeons only allow two or three cortisone shots into any joint. If the shots don’t provide you with lasting relief, your doctor may suggest surgery.

Related Document: A Patient’s Guide to Joint Injections for Arthritis

Preparation

What do I need to do to get ready for surgery?

Some severe degenerative problems of the shoulder may require replacement of the painful shoulder with an artificial shoulder joint. You and your surgeon should make the decision to proceed with surgery together. You need to understand as much about the procedure as possible. If you have concerns or questions, you should talk to your surgeon.

Once you decide on surgery, you need to take several steps. Your surgeon may suggest a complete physical examination by your regular doctor. This exam helps ensure that you are in the best possible condition to undergo the operation.

You may also need to spend time with the physical or occupational therapist who will be managing your rehabilitation after surgery. This allows you to get a head start on your recovery. One purpose of this pre-operative visit is to record a baseline of information. Your therapist will check your current pain levels, ability to do your activities, and the movement and strength of each shoulder.

A second purpose of the pre-operative visit is to prepare you for surgery. You’ll begin learning some of the exercises you’ll use during your recovery. And your therapist can help you anticipate any special needs or problems you might have at home, once you’re released from the hospital.

On the day of your surgery, you will probably be admitted to the hospital early in the morning. You shouldn’t eat or drink anything after midnight the night before. Come prepared to stay in the hospital for several nights. The length of time you will spend in the hospital depends a lot on you.

Surgical Procedure

What happens during shoulder replacement surgery?

Before we describe the procedure, let’s look first at the artificial shoulder itself.

The Artificial Shoulder

There are two major types of artificial shoulder replacements: a cemented prosthesis and an uncemented prosthesis. A cemented prosthesis is held in place by a type of epoxy cement that attaches the metal to the bone. An uncemented prosthesis has a fine mesh of holes on the surface. Bone grows into the mesh. Over time, this anchors the prosthesis to the bone.

Both types of artificial joints are widely used. Your surgeon may also use a combination of the two types. The surgeon determines the type of replacement joint based on your age, your lifestyle, and the surgeon’s experience.

Each prosthesis (artificial joint) is made up of two parts. The humeral component replaces the humeral head, or the ball of the joint. The glenoid component replaces the socket of the shoulder, which is actually part of the scapula.

The humeral component is made of metal. The glenoid component is usually made of two parts. A metal tray attaches directly to the bone, and a plastic cup forms the socket. The plastic is very tough and very slick, much like the articular cartilage it is replacing. In fact, you can ice skate on a sheet of this plastic without causing it much damage.

The Operation

Shoulder replacement surgery can be done in one of two ways. When the cartilage of both the humeral head (the ball) and the glenoid (the socket) is worn away, both parts of the joint must be replaced. This surgery is called arthroplasty, which is the term used for joint reconstruction.

If the glenoid still has some articular cartilage, your surgeon may replace only the humeral head. This procedure is known as a hemiarthroplasty. (Hemi means half.) The hemi-arthroplasty is most commonly used after a fracture of the shoulder where the blood supply to the ball portion (the humeral head) of the humerus is damaged. Research has shown that when the shoulder is being replaced for arthritis, the complete shoulder arthroplasty performs better. Patients have less pain immediately after surgery and in the long run have a better functioning shoulder with less complications and are less likely to need a second operation.

You will most likely need general anesthesia for shoulder replacement surgery. General anesthesia puts you to sleep. It is difficult to numb only the shoulder and arm in a way that makes such a major surgery possible.

Shoulder replacement surgery is done through an incision on the front of your shoulder. This is called an anterior approach. The surgeon cuts through the skin and then isolates the nerves and blood vessels and moves them to the side. The muscles are also moved to the side.

The surgeon enters the shoulder joint itself by cutting into the joint capsule. This allows the surgeon to see the joint.

At this point, the surgeon can prepare the bone for attaching the replacement parts. The ball portion of the humeral head is removed with a bone saw. The hollow inside of the upper humerus is prepared using a rasp. This lets your surgeon mold the space to anchor the metal stem of the humeral component inside the bone.

View animation of removing humeral head

View animation of reaming the humerus

If the glenoid will be replaced, it is prepared by grinding away any remaining cartilage on the surface. This is done with an instrument called a burr. The surgeon usually uses the burr to drill holes into the bone of the scapula. This is where the stem of the glenoid component is anchored.

View animation of preparing the glenoid

View animation of drilling the glenoid

Finally, the humeral component and the glenoid component are inserted and the humeral ball is attached.

View animation of inserting the humeral component

View animation of inserting the glenoid component

View animation of attaching the humeral ball

Once the joint is anchored, the surgeon tests for proper fit. When the surgeon is satisfied with the fit, the joint capsule is stitched together. The muscles are then returned to their correct positions, and the skin is also stitched up.

Your incision will be covered with a bandage, and your arm will be placed in a sling. You will then be woken up and taken to the recovery room.

Complications

What might go wrong?

As with all major surgical procedures, complications can occur. This document doesn’t provide a complete list of the possible complications, but it does highlight some of the most common problems. Some of the most common complications following artificial shoulder replacement are

• anesthesia
• infection
• loosening
• dislocation
• nerve or blood vessel injury

Anesthesia

Most surgical procedures require that some type of anesthesia be done before surgery. A very small number of patients have problems with anesthesia. These problems can be reactions to the drugs used, problems related to other medical complications, and problems due to the anesthesia. Be sure to discuss the risks and your concerns with your anesthesiologist.

Infection

Infection following joint replacement surgery can be very serious. The chances of developing an infection following artificial joint replacement, however, are low (about one percent). Sometimes infections show up very early, before you leave the hospital. Other times infections may not show up for months, or even years, after the operation.

Infection can also spread into the artificial joint from other infected areas. Once an infection lodges in your joint, it is almost impossible for your immune system to clear it. You may need to take antibiotics when you have dental work or surgical procedures on your bladder and colon. The antibiotics reduce the risk of spreading germs to the artificial joint.

Loosening

The major reason that artificial joints eventually fail is that they loosen where the metal or cement meets the bone. A loose joint prosthesis causes pain. Once the pain becomes unbearable, another operation will probably be needed to fix the artificial joint.

There have been great advances in extending the life of artificial joints. However, most will eventually loosen and require another surgery. In the case of artificial knees, you can expect about 12 to 15 years, but artificial shoulder joints tend to loosen sooner.

Dislocation

Just like your real shoulder, an artificial shoulder can dislocate. A shoulder dislocation occurs when the ball comes out of the socket. There is a greater risk of dislocation right after surgery, before the tissues have healed around the new joint. But there is always a slightly increased risk of dislocation with an artificial joint. Your therapist will teach you how to avoid activities and positions that tend to cause shoulder dislocation. A shoulder that dislocates more than once may need another operation to make it more stable.

Related Document: A Patient’s Guide to Shoulder Dislocations

Nerve or Blood Vessel Injury

All of the large nerves and blood vessels to the arm and hand travel through the armpit. (This area is called the axilla.) Because shoulder replacement surgery takes place so close to the axilla, it is possible that the nerves or blood vessels may be injured during surgery. The resulting problems may be temporary if the injury was caused by stretching to hold the nerves out of the way. The nerves and blood vessels rarely suffer any kind of permanent injury after shoulder replacement surgery, but this type of injury can happen.

After Surgery

What happens after surgery?

After surgery, you’ll be transported to the recovery room. You will have a dressing wrapped over your shoulder that will need to be changed frequently over the next few days. Your surgeon may have inserted a small drainage tube into the shoulder joint to help keep extra blood and fluid from building up inside the joint. An intravenous line (IV) will be placed in your arm to give you needed antibiotics and medication.

Your shoulder may be placed in a continuous passive motion (CPM) machine immediately after surgery. CPM helps the shoulder begin moving and alleviates joint stiffness. The machine straps to the shoulder and continuously bends and straightens the joint. This motion is thought to reduce stiffness, ease pain, and keep extra scar tissue from forming inside the joint. You’ll use a shoulder sling to support your arm when you’re not using the CPM machine.

Rehabilitation

What will my recovery be like?

A physical or occupational therapist will see you the day after surgery to begin your rehabilitation program. Therapy treatments will gradually improve the movement in your shoulder. If you are using CPM, your therapist will check the alignment and settings. Your therapist will go over your exercises and make sure you are safe getting in and out of bed and moving about in your room.

When you go home, you may get home therapy visits. By visiting your home, your therapist can check to see that you are safe getting around in your home. Treatments will also be done to help improve your range of motion and strength. In some cases, you may require up to three visits at home before beginning outpatient therapy.

The first few outpatient treatments will focus on controlling pain and swelling. Ice and electrical stimulation treatments may help. Your therapist may also use massage and other types of hands-on treatments to ease muscle spasm and pain. Continue to use your shoulder sling as prescribed.

As the rehabilitation program evolves, more challenging exercises are chosen to safely advance the shoulder’s strength and function.

Finally, a select group of exercises can be used to simulate day-to-day activities, like grooming your hair or getting dressed. Specific exercises may also be chosen to simulate work or hobby demands.

When your shoulder range of motion and strength have improved enough, you’ll be able to gradually get back to normal activities. Ideally, you’ll be able to do almost everything you did before. However, you may need to avoid heavy or repeated shoulder actions.

You may be involved in a progressive rehabilitation program for two to four months after surgery to ensure the best results from your artificial joint. In the first six weeks after surgery, you should expect to see your therapist two to three times a week. At that time, if everything is still going as planned, you may be able to advance to a home program. Then you will only check in with your therapist every few weeks.

A Patient’s Guide to Calcific Tendonitis of the Shoulder

Introduction

Calcific tendonitis of the shoulder happens when calcium deposits form on the tendons of your shoulder. The tissues around the deposit can become inflamed, causing a great deal of shoulder pain. This condition is fairly common. It most often affects people over the age of 40.

This guide will help you understand

• what happens in the shoulder with calcific tendonitis
• what tests your doctor will run to diagnose this condition
• what you can do to help relieve the pain.

Anatomy

Which part of the shoulder is affected?

Calcific tendonitis occurs in the tendons (tendons attach muscles to bones) of the rotator cuff. The rotator cuff is actually made up of several tendons that connect the muscles around your shoulder to the humerus (the larger bone of the upper arm).

Calcium deposits usually form on the tendon in the rotator cuff called the supraspinatus tendon.

There are two different types of calcific tendonitis of the shoulder: degenerative calcification and reactive calcification. The wear and tear of aging is the primary cause of degenerative calcification. As we age, blood flow to the tendons of the rotator cuff decreases. This makes the tendon weaker. Due to the wear and tear as we use our shoulder, the fibers of the tendons begin to fray and tear, just like a worn-out rope. Calcium deposits form in the damaged tendons as a part of the healing process.

Reactive calcification is different. Why it occurs is not clear. It doesn’t seem to be related to degeneration, though it is more likely to cause shoulder pain than degenerative calcification. Doctors think of reactive calcification in three stages. In the pre-calcific stage, the tendon changes in ways that make calcium deposits more likely to form. In the calcific stage, calcium crystals are deposited in the tendons. Then they begin to disappear. The body simply reabsorbs the calcium deposits. Ironically, it is during this stage that pain is most likely to occur. In the post-calcific stage, the body heals the tendon, and the tendon is remodeled with new tissue.

No one knows what triggers the body to reabsorb the deposits. But once this occurs and the tissue begins to be remodeled, the pain usually decreases or goes away altogether.

Related Document: A Patient’s Guide to Shoulder Anatomy

Causes

Why did I develop calcific tendonitis?

No one really knows what causes calcific tendonitis. Severe wear and tear, aging, or a combination of the two are involved in degenerative calcification. Some researchers think that calcium deposits form because there is not enough oxygen to the tendon tissues. Others feel that pressure on the tendons can damage them, causing the calcium deposits to form.

Reactive calcification is even more of a mystery. This type of problem occurs in younger patients and seems to go away by itself in many cases.

Symptoms

What are the symptoms of this condition?

While the calcium is being deposited, you may feel only mild to moderate pain, or even no pain at all. For some unknown reason, calcific tendonitis becomes very painful when the deposits are being reabsorbed. The pain and stiffness of calcific tendonitis can cause you to lose motion in your shoulder. Lifting your arm may become painful. At its most severe, the pain may interfere with your sleep.

Diagnosis

What tests will my doctor run?

Your doctor will take a detailed medical history and do a thorough physical exam of your shoulder. The pain of calcific tendonitis can be confused with other conditions that cause shoulder pain. An X-ray is usually necessary to confirm the presence of calcium deposits. The X-ray will also help pinpoint the exact location of the deposits.

You will probably need to get several X-rays over time. This will help your doctor keep track of the changes in the amount of calcification. By following the changes in the calcium deposits, your doctor can determine whether the condition will heal by itself or perhaps require surgery.

Treatment

How can I get my pain under control?

Nonsurgical Treatment

Your doctor’s first goal will be to help control your pain and inflammation. Initial treatment is likely to be rest and anti-inflammatory medication, such as ibuprofen. The anti-inflammatory medicine is used mainly to control pain. Your doctor may suggest a cortisone injection if your pain stays severe even after trying other nonsurgical treatments. Cortisone is a very powerful steroid. Cortisone can be very effective at temporarily easing inflammation and swelling.

Related Document: A Patient’s Guide to Joint Injections for Arthritis

During the time when the calcium deposits are being reabsorbed, the pain can be especially bad. Your doctor may suggest trying to remove the calcium deposit by inserting two large needles into the area and rinsing with sterile saline. (Saline is simply a saltwater solution.) This procedure is called lavage. Sometimes lavage breaks the calcium particles loose. Then they can be removed with the needles. Getting rid of the calcium deposits can help speed up the healing. Even when lavage fails to remove calcium deposits, it may reduce pressure in the tendon, leading to less pain.

Your doctor will probably have a physical or occupational therapist direct your rehabilitation program. At first, therapy focuses on easing your pain and inflammation. Treatments may include heat or ice. Therapists may apply ultrasound treatments. Ultrasound has shown some benefit in reducing the size of the deposit and in helping people have less pain and better arm function. However, to get the full benefit, ultrasound treatments must be repeated often (up to 24 times) in a six-week period.

Shock wave therapy is a newer form of nonsurgical treatment. It uses a machine to generate shock wave pulses to the sore area. Patients generally receive the treatment once each week for up to three weeks. The impulses are thought to help break up the deposit so the body can more easily absorb it. Recent studies indicate that this form of treatment can help ease pain and reduce the size of the deposit.

Surgery

If the pain and loss of movement continue to get worse or interfere with your daily life, you may need surgery. Surgery for calcific tendonitis does not usually require patients to stay in the hospital overnight. It does require anesthesia.

Arthroscopic Resection

Most surgeries to correct calcific tendonitis of the shoulder are arthroscopic

surgeries. The arthroscope is a special TV camera that can be inserted into the shoulder joint through a small incision in the skin. Other small incisions allow the surgeon to insert small surgical instruments into the joint as well. The surgeon uses the arthroscope to locate the calcium deposit in the rotator cuff tendon. Once the deposit is found, the surgeon uses the small instruments to resect (remove) the calcium deposits and rinse the area. Loose calcium crystals must be removed. They can be very irritating to the surrounding tissues.

Open Resection

In rare instances, open surgery is necessary. In open surgery, the surgeon gets to the calcium deposit by cutting through muscles and other surrounding tissues. The tendon itself is cut to allow removal of the calcium deposits. The surgeon rinses the area to get rid of calcium crystals and then stitches the muscles and skin together.

Rehabilitation

What should I expect after treatment?

Nonsurgical Rehabilitation

Even if you don’t need surgery, you may need to follow a program of rehabilitation exercises. Your doctor may recommend that you work with a physical or occupational therapist for four to six weeks. Your therapist can create an individualized program of strengthening and stretching for your shoulder.

It is very important to strengthen the muscles of the rotator cuff, as these muscles help control the stability of the shoulder joint. Strengthening these muscles can actually decrease the pressure on the calcium deposits in the tendon. Your therapist can also evaluate your workstation or the way you use your body when you do your activities and suggest changes. Simple changes in the way you sit or stand can ease pain and help you avoid further problems.

After Surgery

Rehabilitation after shoulder surgery can be a slow process. You will probably need to attend therapy sessions for six to eight weeks, and you should expect full recovery to take three to four months. Getting the shoulder moving as soon as possible is important. However, this must be balanced with the need to protect the healing tissues.

Your surgeon may have you wear a sling to support and protect the shoulder for a few days after surgery. Ice and electrical stimulation treatments may be used during your first few therapy sessions to help control pain and swelling from the surgery. Your therapist may also use massage and other types of hands-on treatments to ease muscle spasm and pain.

Therapy can progress quickly after a simple arthroscopic resection. Treatments start out with range-of-motion exercises and gradually work into active stretching and strengthening. You just need to be careful to avoid doing too much, too quickly.

Therapy goes slower after open surgery, where the shoulder muscles have been cut. Therapists will usually wait up to two to three weeks before starting range-of-motion exercises. Exercises begin with passive movements. In passive exercises, your shoulder joint is moved, but your muscles stay relaxed. Your therapist gently moves your joint and gradually stretches your arm. You may be taught how to do passive exercises at home.

Active therapy starts four to six weeks after surgery. You use your own muscle power in active range-of-motion exercises. You may begin with light isometric strengthening exercises. These exercises work the muscles without straining the healing tissues.

At about six weeks you start doing heavier strengthening. Exercises focus on improving the strength and control of the rotator cuff muscles and the muscles around the shoulder blade. Your therapist will help you retrain these muscles to keep the ball of the humerus in the socket. This helps your shoulder move smoothly during all your activities.

Some of the exercises you’ll do are designed get your shoulder working in ways that are similar to your work tasks and sport activities. Your therapist will help you find ways to do your tasks that don’t put too much stress on your shoulder. Before your therapy sessions end, your therapist will teach you a number of ways to avoid future problems.

A Patient’s Guide to Impingement Syndrome

Introduction

The shoulder is a very complex piece of machinery. Its elegant design gives the shoulder joint great range of motion, but not much stability. As long as all the parts are in good working order, the shoulder can move freely and painlessly.

Many people refer to any pain in the shoulder as bursitis. The term bursitis really only means that the part of the shoulder called the bursa is inflamed. Tendonitis is when a tendon gets inflamed. This can be another source of pain in the shoulder. Many different problems can cause inflammation of the bursa or tendons. Impingement syndrome is one of those problems. Impingement syndrome occurs when the rotator cuff tendons rub against the roof of the shoulder, the acromion.

This guide will help you understand

• what happens in your shoulder when you have impingement syndrome
• what tests your doctor will run to diagnose this condition
• how you can relieve your symptoms.

Anatomy

What part of the shoulder is affected?

The shoulder is made up of three bones: the scapula (shoulder blade), the humerus (upper arm bone), and the clavicle (collarbone).

The rotator cuff connects the humerus to the scapula. The rotator cuff is formed by the tendons of four muscles: the supraspinatus, infraspinatus, teres minor, and subscapularis.

Tendons attach muscles to bones. Muscles move the bones by pulling on the tendons. The rotator cuff helps raise and rotate the arm.

As the arm is raised, the rotator cuff also keeps the humerus tightly in the socket of the scapula, the glenoid. The upper part of the scapula that makes up the roof of the shoulder is called the acromion.

A bursa is located between the acromion and the rotator cuff tendons. A bursa is a lubricated sac of tissue that cuts down on the friction between two moving parts. Bursae are located all over the body where tissues must rub against each other. In this case, the bursa protects the acromion and the rotator cuff from grinding against each other.

Related Document: A Patient’s Guide to Shoulder Anatomy

Causes

Why do I have problems with shoulder impingement?

Usually, there is enough room between the acromion and the rotator cuff so that the tendons slide easily underneath the acromion as the arm is raised. But each time you raise your arm, there is a bit of rubbing or pinching on the tendons and the bursa. This rubbing or pinching action is called impingement.

Impingement occurs to some degree in everyone’s shoulder. Day-to-day activities that involve using the arm above shoulder level cause some impingement. Usually it doesn’t lead to any prolonged pain. But continuously working with the arms raised overhead, repeated throwing activities, or other repetitive actions of the shoulder can cause impingement to become a problem. Impingement becomes a problem when it causes irritation or damage to the rotator cuff tendons.

Raising the arm tends to force the humerus against the edge of the acromion. With overuse, this can cause irritation and swelling of the bursa. If any other condition decreases the amount of space between the acromion and the rotator cuff tendons, the impingement may get worse.

Bone spurs can reduce the space available for the bursa and tendons to move under the acromion. Bone spurs are bony points. They are commonly caused by wear and tear of the joint between the collarbone and the scapula, called the acromioclavicular (AC) joint. The AC joint is directly above the bursa and rotator cuff tendons.

In some people, the space is too small because the acromion is oddly sized. In these people, the acromion tilts too far down, reducing the space between it and the rotator cuff.

Symptoms

What does impingement syndrome feel like?

Impingement syndrome causes generalized shoulder aches in the condition’s early stages. It also causes pain when raising the arm out to the side or in front of the body. Most patients complain that the pain makes it difficult for them to sleep, especially when they roll onto the affected shoulder.

A reliable sign of impingement syndrome is a sharp pain when you try to reach into your back pocket. As the condition worsens, the discomfort increases. The joint may become stiffer. Sometimes a catching sensation is felt when you lower your arm. Weakness and inability to raise the arm may indicate that the rotator cuff tendons are actually torn.

Related Document: A Patient’s Guide to Rotator Cuff Tears

Diagnosis

What tests will my doctor run?

The diagnosis of bursitis or tendonitis caused by impingement is usually made on the basis of your medical history and physical examination. Your doctor will ask you detailed questions about your activities and your job, because impingement is frequently related to repeated overhead activities.

Your doctor may order X-rays to look for an abnormal acromion or bone spurs around the AC joint. A magnetic resonance imaging (MRI) scan may be performed if your doctor suspects a tear of the rotator cuff tendons. An MRI is a special imaging test that uses magnetic waves to create pictures that show the tissues of the shoulder in slices. The MRI scan shows tendons as well as bones. The MRI scan is painless and requires no needles.

An arthrogram may also be used to detect rotator cuff tears. The arthrogram is an older test than the MRI, but it is still widely used. It involves injecting dye into the shoulder joint and then taking several X-rays. If the dye leaks out of the shoulder joint, it suggests that there is a tear in the rotator cuff tendons.

In some cases, it is unclear whether the pain is coming from the shoulder or a pinched nerve in the neck. An injection of a local anesthetic (such as lidocaine) into the bursa can confirm that the pain is in fact coming from the shoulder. If the pain goes away immediately after the injection, then the bursa is the most likely source of the pain. Pain from a pinched nerve in the neck would almost certainly not go away after an injection into the shoulder.

Treatment

What treatment options are available?

Nonsurgical Treatment

Doctors usually start by prescribing nonsurgical treatment. You may be prescribed anti-inflammatory medications such as aspirin or ibuprofen. Resting the sore joint and putting ice on it can also ease pain and inflammation. If the pain doesn’t go away, an injection of cortisone into the joint may help. Cortisone is a strong medication that decreases inflammation and reduces pain. Cortisone’s effects are temporary, but it can give very effective relief for up to several months.

Related Document: A Patient’s Guide to Joint Injections for Arthritis

Your doctor may also prescribe sessions with a physical or occupational therapist. Your therapist will use various treatments to calm inflammation, including heat and ice. Therapists use hands-on treatments and stretching to help restore full shoulder range of motion. Improving strength and coordination in the rotator cuff and shoulder blade muscles lets the humerus move in the socket without pinching the tendons or bursa under the acromion. You may need therapy treatments for four to six weeks before you get full shoulder motion and function back.

Surgery

If you are still having problems after trying nonsurgical treatments, your doctor may recommend surgery.

Subacromial Decompression

The goal of surgery is to increase the space between the acromion and the rotator cuff tendons. Taking pressure off the tissues under the acromion is called subacromial decompression. The surgeon must first remove any bone spurs under the acromion that are rubbing on the rotator cuff tendons and the bursa. Usually the surgeon also removes a small part of the acromion to give the tendons even more space. In patients who have a downward tilt of the acromion, more of the bone may need to be removed. Surgically cutting and shaping the acromion is called acromioplasty. It gives the surgeon another step to get pressure off (decompress) the tissues between the humerus and the acromion.

Resection Arthroplasty

Impingement may not be the only problem in an aging or overused shoulder. It is very common to also see degeneration from arthritis in the AC joint. If there is reason to believe that the AC joint is arthritic, the end of the clavicle may be removed during impingement surgery. This procedure is called a resection arthroplasty.

The most common procedure for AC joint osteoarthritis is resection arthroplasty. A resection arthroplasty involves removing a small portion of the end of the clavicle. This leaves a space between the acromion (the piece of the scapula that meets your shoulder) and the cut end of the clavicle, where the joint used to be. Your surgeon will take care not to remove too much of the end of the clavicle to prevent any damage to the ligaments holding the joint together. Usually only a small portion is removed, less than one cm (about three-eighths of an inch). As your body heals, the joint is replaced by scar tissue. Remember, the AC joint doesn’t move much, but it does need to be flexible. The scar tissue allows movement but stops the bone ends from rubbing together.

This procedure can be done in two ways. Today, it is more common to do this procedure using the arthroscope. An arthroscope is a slender tool with a tiny TV camera on the end. It lets the surgeon work in the joint through a very small incision. This may result in less damage to the normal tissues surrounding the joint, leading to faster healing and recovery.

Related Document: A Patient’s Guide to Osteoarthritis of the Acromioclavicular Joint

Arthroscopic Procedure

Today, acromioplasty is usually done using an arthroscope.

An arthroscope is a special type instrument designed to look into a joint, or other space, inside the body. The arthroscope itself is a slender metal tube smaller than a pencil. Inside the metal tube are special strands of glass called fiberoptics. These small strands of glass form a lens that allows one to look into the tube on one end and see what is on the other side – inside the space. This is similar to a microscope or telescope. In the early days of arthroscopy, the surgeon actually looked into one end of the tube. Today, the arthroscope is attached to a small TV camera. The surgeon can watch the TV screen while the arthroscope is moved around in the joint. Using the ability to see inside the joint, the surgeon can then place other instruments into the joint and perform surgery while watching what is happening on the TV screen.

The arthroscope lets the surgeon work in the joint through a very small incision. This may result in less damage to the normal tissues surrounding the joint, leading to faster healing and recovery. If your surgery is done with the arthroscope, you may be able to go home the same day.

To perform the acromioplasty using the arthroscope, several small incisions are made to insert the arthroscope and special instruments needed to complete the procedure. These incisions are small, usually about one-quarter inch long. It may be necessary to make three or four incisions around the shoulder to allow the arthroscope to be moved to different locations to see different areas of the shoulder.

A small plastic, or metal, tube is inserted into the shoulder and connected with sterile plastic tubing to a special pump. Another small tube allows the fluid to be removed from the joint. This pump continuously fills the shoulder joint with sterile saline (salt water) fluid. This constant flow of fluid through the joint inflates the joint and washes any blood and debris from the joint as the surgery is performed.

There are many small instruments that have been specially designed to perform surgery in the joint. Some of these instruments are used to remove torn and degenerative tissue. Some of these instruments nibble away bits of tissue and then vacuum them up from out of the joint. Others are designed to burr away bone tissue and vacuum it out of the joint. These instruments are used to remove any bone spurs that are rubbing on the tendons of the shoulder and smooth the under surface of the acromion and AC joint.

Open Procedure

In other cases, an open incision is made to allow removal of the bone. Usually an incision about three or four inches long is made over the top of the shoulder. The surgeon removes any bone spurs and a part of the acromion. The surgeon then smooths the rough ends of the bone. If necessary, the surgeon will do a resection arthroplasty on the AC joint. If you have open surgery, you may need to spend a night or two in the hospital.

View animation of bone spur removal

Rehabilitation

What should I expect after treatment?

Nonsurgical Rehabilitation

Even if you don’t need surgery, you may need to follow a program of rehabilitation exercises. Your doctor may recommend that you work with a physical or occupational therapist. Your therapist can create an individualized program of strengthening and stretching for your shoulder and rotator cuff.

It is important to maintain the strength in the muscles of the rotator cuff. These muscles help control the stability of the shoulder joint. Strengthening these muscles can actually decrease the impingement of the acromion on the rotator cuff tendons and bursa. Your therapist can also evaluate your workstation or the way you use your body when you do your activities and suggest changes to avoid further problems.

After Surgery

Rehabilitation after shoulder surgery can be a slow process. You will probably need to attend therapy sessions for several weeks, and you should expect full recovery to take several months. Getting the shoulder moving as soon as possible is important. However, this must be balanced with the need to protect the healing muscles and tissues.

Your surgeon may have you wear a sling to support and protect the shoulder for a few days after surgery. Ice and electrical stimulation treatments may be used during your first few therapy sessions to help control pain and swelling from the surgery. Your therapist may also use massage and other types of hands-on treatments to ease muscle spasm and pain.

Therapy can progress quickly after a simple arthroscopic procedure. Treatments start out with range-of-motion exercises and gradually work into active stretching and strengthening. You just need to be careful to avoid doing too much, too quickly.

Therapy goes slower after open surgery in which the shoulder muscles have been cut. Therapists will usually wait up to two weeks before starting range-of-motion exercises. Exercises begin with passive movements. During passive exercises, your shoulder joint is moved, but your muscles stay relaxed. Your therapist gently moves your joint and gradually stretches your arm. You may be taught how to do passive exercises at home.

Active therapy starts four to six weeks after surgery. You use your own muscle power in active range-of-motion exercises. You may begin with light isometric strengthening exercises. These exercises work the muscles without straining the healing tissues.

At about six weeks you start doing more active strengthening. Exercises focus on improving the strength and control of the rotator cuff muscles and the muscles around the shoulder blade. Your therapist will help you retrain these muscles to keep the ball of the humerus in the socket. This helps your shoulder move smoothly during all your activities.

Some of the exercises you’ll do are designed get your shoulder working in ways that are similar to your work tasks and sport activities. Your therapist will help you find ways to do your tasks that don’t put too much stress on your shoulder. Before your therapy sessions end, your therapist will teach you a number of ways to avoid future problems.