The following sections will review the risk factors for this condition, typical signs and symptoms, diagnosis and treatment options. It is important for patients to realize that many of the prescribed treatments are not curative rather are designed to alleviate symptoms while the disease runs its course.
The glenohumeral joint (ball and socket joint) is surrounded by a fibrous capsule that is reinforced with several ligaments. This capsule/ligament complex serves several functions: 1) keep the joint water tight; 2) provide support to help hold the ball in the socket at the end ranges of shoulder motion; 3) provide sufficient volume to allow the shoulder to move through an incredibly wide range to position the hand in space.
When frozen shoulder syndrome occurs, this capsule becomes inflamed, thickened and contracted. This process dramatically affects shoulder mobility. The contracted capsule prematurely reaches maximal stretch before the shoulder reaches its normal end range of motion. As the capsule contracture increases, shoulder motion decreases.
Certain types of frozen shoulder can also occur from scar tissue that develops between the muscle layers of the shoulder joint and shoulder girdle.
Idiopathic: This terms indicates that the cause is unknown. Idiopathic cases account for the majority of patients presenting with onset of shoulder stiffness.
Diabetes, hyperthyroidism (overactive thyroid), cardiovascular disease, lung disease, depression and Parkinsons disease have all been associated with frozen shoulder syndrome. Diabetes has the most notable association and frozen shoulder may occur in roughly 15% of diabetic patients, particularly those who have been on insulin treatment for greater than 10 years.
Shoulder surgery for conditions such as rotator cuff tear, proximal humerus fracture, shoulder instability and arthritis may result in stiffness due to aggressive scar formation during the healing process. Prolonged immobilization to protect a surgical repair may lead to stiffness. Frozen shoulder syndrome has also been reported following neck surgery, open heart surgery, and radiation therapy for breast and lung cancer.
Post-traumatic: Shoulder or arm injury may result in a frozen shoulder from prolonged immobilization, scar formation during tissue healing or from a mechanical block to movement as may occur if bony fractures heal in the wrong position.
Risk Factors: In addition to the risk factors of prolonged immobility, diabetes and other systemic illnesses mentioned above, age and gender are also risk factors for frozen shoulder. This condition occurs more frequently in women and most commonly between the ages of 40-65. The average age from a large series of patients followed with this condition was 55 years.
Stages of the Disease:
Note: these phases apply only to idiopathic frozen shoulder and that which develops from systemic illness. They do not apply to post-operative and posttraumatic frozen shoulder.
Inflammatory Phase: this initial phase occurs over 3 weeks to 3 months and is marked by relatively severe shoulder pain. During this phase, the capsule becomes inflamed and the process of thickening and contracture begin. Initially, pain predominates without significant stiffness, but gradual loss of motion ensues. Pain at rest and night pain accompany pain with active use.
Freezing Phase: during this phase, shoulder motion continues to decrease until it approaches a minimum range. Pain increases during this phase approaching a plateau. The time course of freezing is variable but generally lasts between 3 months and 9 months after the onset of frozen shoulder.
Frozen Phase: this phase is characterized by fixed loss of motion that does not increase or decrease. The shoulder remains uncomfortable during active use as well as at night. Pain diminishes relative to the first two phases and is more manageable. The frozen phase also varies in duration but may lasts between 6 months to a year.
Thawing Phase: Thawing is marked by gradual return in range of motion and progressively decreasing pain. The shoulder is no longer irritable. This phase generally begin somewhere between 1-2 years after the onset of frozen shoulder.
Symptoms and Signs:
Symptoms: Progressively worsening pain without preceding injury is the typical history of a frozen shoulder. Patients often think they have bursitis or a rotator cuff tear because the shoulder hurts with active use. Strength is generally unaffected but limited by pain. Increasing difficulty with daily activities including dressing and hygiene are common complaints. Night pain and pain that awakens patients from sleep is one of the most troublesome symptoms. Some patients have pain that radiates into the neck, back or upper arm due to shoulder fatigue.
Signs: the physical exam of a frozen shoulder demonstrates loss of both active and passive motion. This motion loss may be globally restricted in all ranges or may be focally restricted in specific ranges. Loss of internal rotation (ability to put the hand behind the back) is usually the most affected. Strength testing generally indicates intact rotator cuff function. Rotation of the ball in the socket is smooth and without grating as occurs in arthritis.
How is a Frozen Shoulder Diagnosed?
In straight forward cases, the patients history and physical exam may be all that is necessary to make a diagnosis of frozen shoulder. If the exam raises suspicion that the frozen shoulder may have developed secondary to another problem such as a rotator cuff tear or fracture, X-rays may be helpful to screen for other underlying causes. In the absence of previous injury or surgery, the X-rays of a frozen shoulder that is classified as idiopathic or due to systemic illness are usually normal.
Other imaging studies as MRI and arthrograms may also be helpful in ruling out underlying causes such as rotator cuff disease. These studies may also show capsular contracture and thickening.
What is the Natural History of Frozen Shoulder Syndrome?
Generally speaking, frozen shoulder syndrome is a self-limited process that resolves with time. The time it will take for the disease to run its course cannot be predicted in any one case. On average frozen shoulder syndrome lasts between 9 and 18 months. There are a few exceptions to this rule. Firstly, frozen shoulders in diabetics behave somewhat differently: they last longer, they are more resistant to treatment and they are more likely to recur. Secondly, post-operative or posttraumatic frozen shoulders may not resolve spontaneously. Because the stiffness in these cases results from actual scar tissue forming between tissue layers rather than an inflammatory contracture of the shoulder capsule, these types of frozen shoulder may require more aggressive treatment.
What is the Chance of Recurrence?
Idiopathic frozen shoulder has little chance of recurrence once fully resolved. The highest chance of recurrence is for patients with diabetes. There is a 50% chance that frozen shoulder could occur on the opposite side and a 30-50% chance that it could return on the affected side.
How is Frozen Shoulder Treated?
The mainstays of treatment for these types of frozen shoulder are activity modification, physical therapy and home exercises, non-steroidal anti-inflammatory medications and patience.
Activity Modification: patients with frozen shoulder are encouraged to remain active and use the affected extremity. Activities which stress the shoulder and cause significantly worsening pain, however, may increase the inflammation in the shoulder capsule. This is particularly true in the inflammatory and freezing phases of the disease. Trying to work through the pain is not recommended, and patients may have to modify their work and recreational activities until the pain reaches a plateau.
Physical Therapy: the goals of physical therapy are as follows: 1) gently stretch the shoulder to prevent worsening stiffness and improve mobility; 2) decrease pain and inflammation through techniques such as ultrasound and cold therapy; 3) gently strengthen the rotator cuff and shoulder girdle muscles to prevent atrophy from disuse of the shoulder; 4) instruct patients on the proper techniques for a home exercise program. We generally recommend that patients attend a structured physical therapy program for about 6 weeks to accomplish these goals. Physical therapy may be most effective in the frozen phase of the disease. Overly aggressive stretching during the inflammatory and freezing phases may actually worsen inflammation and prolong the disease and patients should avoid trying to work through the pain.
Home Exercise Program: gentle stretching exercises should be performed 2- 3 times daily to prevent adhesions from reforming between therapy sessions. As much as possible, these sessions should be performed after the shoulder has been relaxed by a hot shower, bath, or aerobic exercise. An important principle of the stretching exercises is to allow the muscles to relax so that the stretch can be applied to the soft tissues without muscle interference. Tissues of a tight shoulder do not like to be stretched suddenly, roughly, or with a lot of force. Thus the strategy is to apply a gentle stretch so that at most minimal soreness results. Any soreness should go away within 15 minutes after you stop the exercises. Improvement in the range of motion and comfort may not begin until six weeks of persistence with the program. One should not stop these exercises until the frozen shoulder has regained normal motion and comfort.
NOTE: Many patients will have engaged in previous program of physical therapy but may have failed to improve. Often, the programs have focused on muscle strengthening exercises for a presumed diagnosis of rotator cuff tendonitis or impingement syndrome. Little emphasis will have been placed on a thorough and comprehensive flexibility program, and muscle strengthening may actually increase shoulder pain in the early phases of the process. Our repeated observation is that may patients who have failed previous physical therapy will benefit from further treatment once the appropriate diagnosis has been established and the exercises focused on stretching rather than strengthening. This in combination with a properly performed home exercise program will often provide substantial benefit with time and persistence. Most importantly, patients must recognize that recovery of motion is a slow process. One should not give up if immediate and early gains are not seen.
Non-steroid Anti-inflammatory Medications (NSAIDS): these medications include Ibuprofen, Motrin, Advil, Naprosyn, Alleve, Bextra, Celebrex, and many others. They act both to reduce inflammation and to relieve pain. They may be more effective in the early phases of frozen shoulder syndrome when the shoulder capsule is inflamed. Once the inflammatory process has plateaued and patients reach the frozen phase, these medications are not likely to have significant benefit. Long term use of NSAIDS may be associated with risks such as irritation of the stomach lining, ulcers and kidney problems. Patients should become informed about the possible short and long-term side effects of each medication prior to use.
Other Medications: Narcotic pain medications, muscle relaxants and sleepingpills are generally not recommended for frozen shoulder syndrome as prolonged use may diminish their effectiveness and may cause medication dependence or even addiction.
Other non-operative treatments for frozen shoulder syndrome include cortisone injections into the shoulder joint, nerve blocks, and acupuncture.
Cortisone Injections: Cortisone is a powerful anti-inflammatory medication that can be injected directly into the shoulder joint so that it acts locally on the inflamed shoulder capsule. As with oral medications, it may be most effective in the inflammatory and freezing phases of the process which are dominated by inflammation. Occasionally, 2-3 shots spaced over several months may be necessary to have an effect. The results of this treatment are variable and some patients do not respond. Nevertheless, cortisone injections remain a reasonable alternative in patients with moderate to severe discomfort whose quality of life is significantly affected by the disease. The injections are generally well tolerated and have minimal sideeffects. In patients with diabetes, cortisone shots may temporarily elevate the blood sugar and careful glucose level monitoring is recommended for the first few days after treatment.
Nerve Blocks: the suprascapular nerve supplies sensation to the shoulder capsule. There is growing evidence that blocking this nerve with a series of injections may help alleviate some of the discomfort of frozen shoulder. These injections are performed by the anesthesiologists who use a device called a nerve stimulator to target the injection into the proper location. Nerve blocks are not a cure for frozen shoulder. Rather, their purpose is to reduce the effect of shoulder discomfort on the patients quality of life and facilitate a home exercise program.
Acupuncture: This is an ancient medicinal art that uses needles inserted into the body at points along the meridians just under the skin. These needles stimulate, disperse and balance the flow of energy, relieve pain, and treat a variety of chronic, acute and degenerative conditions. There is anecdotal evidence that acupuncture may be helpful in managing the pain associated with frozen shoulder. As with most other treatments, however, acupuncture is not a cure and does not necessarily shorten the course of the disease.
Who Should Consider Surgery?
Surgery may be considered if a concerted effort at non-operative treatment has failed to result in improvement in comfort and function after 6-9 months. Surgery is entirely elective. The decision should be based on how frozen shoulder syndrome affects a persons quality of life and ones tolerance for waiting out the process.
Surgery should be performed during the frozen phase of the disease process. Surgery performed during the inflammatory or freezing phases is likely to fail with recurrence of shoulder pain and stiffness. If patients have reached the thawing phase, surgery is not indicated as resolution can be expected with further nonoperative treatment.
Patients with post-operative, post-traumatic and diabetic frozen shoulder may be more likely to require to surgery as the chance of spontaneous resolution is less for these types of frozen shoulder. In post-operative cases, surgery should generally not be performed until 4-6 months after the original operation to minimize the risk of further injury to healing tissues.
The success of surgery can be maximized if patients are motivated and committed to the recovery process. Thus, one should not consider this course unless a substantial allotment of time and effort can be devoted to the goal of a comfortable and functional shoulder. The gains made at surgery are otherwise easily lost
What Does Surgery Entail?
In cases of idiopathic frozen shoulder and in some post-operative and posttraumatic cases, a manipulation under anesthesia may be all that is necessary to free up the stiff shoulder. This procedure involves putting the patient to sleep both to block pain and provide muscle relaxation. The shoulder is then forcefully stretched in all directions. This process usually tears the contracted shoulder capsule and any adhesions that have formed between the joint surface and muscle layers. Following the manipulation, cortisone is injected into the shoulder joint to hinder further post-operative scar formation and aid in post-manipulation pain relief.
In some instances, if the scar tissue is too thick, a manipulation under anesthesia may not succeed in restoring shoulder motion. In these cases, an arthroscopic surgery is required to cut and resect portions of the capsule that are too contracted to respond to manipulation. This surgery is called an arthroscopic capsular release. Once the capsule has been released, the shoulder is manipulated again until full motion is achieved. Arthroscopic surgery has the advantage of looking inside the joint so that any other problems can be assessed and treated if necessary.
Patients with a diabetic frozen shoulder always require an arthroscopic capsular release in addition to a manipulation under anesthesia. This is not because the capsule is overly contracted, but because the recurrence rate after manipulation alone is unacceptably high. By removing portions of the shoulder capsule, the likelihood of recurrence is reduced.
In many cases, an implantable pain pump is inserted into the shoulder joint. The pump delivers numbing medication at a slow and steady rate to provide pain relief for 48 hours following the operation. This extended window of analgesia facilitates early range of motion and helps reduce muscle spasms. Once the pump is empty, the patient removes the tubing from the shoulder and discards the pump system.
What Does Recovery Involve?
Recovery from a manipulation under anesthesia with or without an arthroscopic capsular release involves immediate range of motion exercises to prevent recurrent stiffness. Slings are highly discouraged as they only promote stiffness. There are no specific restrictions as far as lifting, pushing, pulling or using the arm for other activities. Generally, the shoulder may be sore for a few weeks following surgery and overly aggressive use of the extremity is discouraged so that the shoulder does not become inflamed.
We routinely employ continuous passive motion machines for two weeks after surgery for frozen shoulder. These machines are set up in the patients home and take the arm through a range of motion at a controlled rate. Because the machine does the work of the muscles, passive motion facilitates muscle relaxation and improves early motion. This is critical to preventing adhesions from forming between tissue planes. Patients are instructed on how to use these machines prior to surgery so that when they return home from the hospital they may immediately start the process. Generally, the CPM machine should be used 3-4 times per day for 45-60 minutes each session.
Non-steroidal anti-inflammatory medications and ice are useful modalities to reduce pain and swelling and also discourage scar tissue formation. Patients who can tolerate NSAIDS are encouraged to use them for a period of 3 weeks following surgery. Ice should be used following CPM and exercise sessions for 20-30 minutes at a time.
Patients are encouraged to attend outpatient physical therapy following surgery in addition to a daily home exercise program to maintain shoulder flexibility. The home exercises are critically important as formal therapy sessions may only be scheduled 2-3 days per week. The propensity to form new scar tissue exists for at least 6 weeks after both manipulation and arthroscopic capsular release. Thus, a maintenance flexibility program is essential we after surgery
Potential Risks and Complications of Surgery:
The risks of surgery include, but are not limited to, infection, damage to nerves and blood vessels, fracture of the humerus, instability of the shoulder joint, recurrent stiffness and complications related to anesthesia. While these risks and complications are infrequent, they can occur in anyone. Patients should consider these when electing to undergo surgery. Any one of these problems can limit the outcome of the procedure.