What is a Frozen Shoulder?
“Frozen shoulder” is a term that describes a pathological condition that is characterized primarily by painful stiffness.
The patient presents a loss of range of motion in more than one direction.
The medical term for frozen shoulder is adhesive capsulitis and describes an inflammatory condition that affects the entire rotator cuff and the underlying joint capsule leading to tissue shrinkage and adhesion of the follicle to adjacent tissues (e.g. femoral head).
The result is that the patient is in pain and unable to perform simple daily exercises.
Normal shoulder movement varies greatly and some people experience greater loosening of their joints than others within the normal range of motion.
Image: The normal shoulder joint is loose so that the shoulder can move in any direction (left). With the development of adhesive capsulitis, irritation and inflammation leads to capsule contracture.
Frozen shoulder – Causes
The causes that can lead to ‘frozen shoulder’ conditions are many and can be classified as primary and secondary. The primary causes include the idiopathic “frozen shoulder” (without known cause) while the secondary causes include diabetes mellitus, injury and surgery.
Despite the differences, which will be described below, all variants of the frozen shoulder involve some degree of inflammation of the joint (folliculitis) and this leads to scar tissue, adhesions and ultimately to rupture. The exact causes remain unclear, but they appear to be the result of “abnormal” cellular activity that leads to inflammation and scar tissue formation.
Women are more frequently affected than men, and patients with diabetes mellitus are four times more likely to develop adhesive capsulitis. Finally, the risk for the other shoulder to develop the same symptoms is considered high.
Image: On the normal shoulder (left) the ligaments and pouch are thin and white. On the frozen shoulder (right), the joint capsule appears red and edematous due to inflammatory reaction.
Duration of Symptoms
In the case of adhesive capsulitis, three phases have been described. These include:
Stage 1: (Invasion) The onset of pain and the onset of decrease in the range of abduction and rotation movements. “The shoulder begins to freeze”
Stage 2: (Stabilization) Pain reduction accompanied by severe stiffness. The shoulder cannot be abducted and cannot be flexed. ‘Frozen shoulder’
Stage 3: (Restoration) It is characterized by gradual improvement of movement and reduction of pain. “Defrozen shoulder”
The duration of all three stages can range from 4 to 20 months. However, the stages of the condition may not be as distinct and clear and overlap.
In particular, some patients continue to experience severe pain even when the shoulder becomes extremely stiff.
What are the Symptoms?
The diagnosis of frozen shoulder is difficult and often the condition is underdiagnosed by the orthopedist that has a tendency to associate shoulder pain with the pathology of the rotator cuff of the shoulder. The typical patient suffering from idiopathic adhesive capsulitis is a woman who reports the onset of pain after a minor injury or even without any injury. Subsequently, there is a decrease in the range of motion, and sometimes surgery for tendonitis or rupture of the rotator cuff is recommended, which exacerbates the existing symptoms. The patient, as mentioned above, has a painful decrease in the range of motion of the joint. In most cases, it is advisable to request an X-ray to confirm that the pain and loss of movement is not due to arthritic lesions.
Frozen Shoulder – Diagnosis
The diagnosis of the disease is mainly based on the clinical symptoms and the patient’s medical history. If the patient describes a gradual loss of movement without trauma, the orthopedist should suspect the possibility of a frozen shoulder. Radiological examination will rule out osteoarthritis; however, this is a possible cause if the patient only experiences a brief stiffness period. The patient may experience loss of movement following shoulder surgery. Stiffness can occur after a variety of shoulder surgeries, including restoration of the rotator cuff tendon rupture, repair of shoulder instability or osteosynthesis of a fracture.
Physical examination will highlight not only the loss of active movement but also of passive movement in all directions. Shoulder strength testing is normal unless combined with rotator cuff disease.
There are several factors that contribute to the development of frozen shoulder. In the case of the idiopathic frozen shoulder, the joint capsule thickens and contracts. In the case of post-traumatic frozen shoulder (e.g. after a fracture) the scar tissue may include not only the follicle but also the adjoining tissues.
Finally, in the case of postoperative stiffness after restoring shoulder instability, the ligaments and the joint capsule at the anterior part of the joint are contracted, limiting mainly the outward flexion of the shoulder. In the worst case, tensed joints may push the head of the humerus backwards, gradually leading to osteoarthritis.
Frozen Shoulder – Treatment
- In the case of adhesive capsulitis, the majority of patients recover either without treatment or with a mild physiotherapy program.
- In patients with severe pain and mild stiffness, cortisone infusion at the joint provides significant relief and may shorten the recovery time.
- In those rare cases of chronic stiffness that do not respond to conservative treatment, surgical treatment is recommended. In cases of idiopathic frozen shoulder, surgery is rarely necessary, while in the secondary frozen shoulder (mainly post-traumatic and post-operative) it is the only solution.
- In the case of stiffness following shoulder instability surgery, it is reasonable to worry. Loss of outward rotation without treatment can contribute to the development of osteoarthritis. Therefore, when stiffness is present, surgical treatment should be recommended.
- In the case of stiffness following surgical repair of a fracture, adhesions can be extensive and include not only the joint capsule, but also the adjacent tissues. These are cases that do not respond to conservative treatment and require surgery.
MOBILIZATION – HANDLING UNDER ANESTHESIA
Historically, this is the most popular method for many surgeons.
According to this method and with the patient under anesthesia, certain manipulations are attempted in each direction to “break” the adhesions and restore shoulder movement.
Although it has proven its effectiveness as a method, it can lead to complications such as:
Dislocation of the head of the humerus
Patients with diabetes mellitus are at greater risk of relapsing.
Today, the arthroscopic method is an emerging therapeutic alternative.
ARTHROSCOPIC RELEASE OF THE JOINT CAPSULE
Arthroscopic release of the joint capsule was first tested during the late 1990s and has since been established as a well-known and effective method that seems to completely restore the range of motion of the joint.
Anesthesia during surgery and pain control after arthroscopic release are considered very important parameters.
In some cases it is preferable to use nerve blocking to maintain analgesia 24 to 48 hours postoperatively.
The release of adhesions and joint capsule contracture is performed with the help of the arthroscope, a thin tube inserted into the joint (through a very small incision) that provides a satisfactory view of the contracted capsule.
Next, special tools for releasing adhesions are inserted.
The arthroscope is inserted from the back of the shoulder and as a first step the anterior part of the joint capsule is released.
The capsule usually is depicted reds and thickened due to the inflammatory reaction.
Re-insertion of the arthroscope and tools from other very small incisions releases the posterior part of the joint capsule as well.
Finally, adhesions can also develop between the rotator cuff and the acromion.
These are adequately treated with the arthroscopic method.
In most cases the patient is hospitalized for 24-48 hours.
Thus, the interscalenic catheter will provide pain relief.
During this period, the patient undergoes physiotherapy.
After discharge, the patient removes the suspension and begins stretching exercises explained by the physiotherapist, while using the limb normally for all daily activities.
OPEN SURGICAL INTERVENTION
Patients with large adhesions or with adhesions located around the joint capsule may require open-release surgery.
The steps include arthrotomy and release of adhesions between various anatomical shoulder planes and sometimes elongation of the tendons.
Overall, the results after arthroscopic and open release of adhesions are excellent.
However, the extent of contracture and damage due to previous surgeries results in worse functional outcomes.
Finally, patients with idiopathic frozen shoulder usually have better results than patients with frozen shoulder due to previous surgery or injury.