What is Frozen shoulder?
Frozen shoulder, or adhesive capsulitis, is an inflammatory disorder of the shoulder that causes fibrosis (scarring) of the joint capsule leading to pain and loss of motion. The capsule of the shoulder is normally a very thin, elastic layer of tissue that forms the wall of the joint and assists with shoulder stability. In patients suffering from capsulitis, this lining becomes very thickened and inflamed resulting in stiffness and loss of motion of the shoulder. Frozen shoulder has classically been described as a self-limited process with three distinct phases: freezing, frozen, and thawing. The freezing phase is the first stage and typically is highlighted by gradual onset of pain and gradual loss of motion. This phase can last from 6 weeks to 9 months. The frozen phase is the stiff phase. Typically during this time, the pain may gradually improve but the patient’s shoulder remains stiff. This phase can last anywhere from 4-8 months. The final phase, thawing, is marked by gradual resolution of motion and can take anywhere from 5-26 months to run its course.
Most patients with adhesive capsulitis are women aged 40-60. In fact, women are five times more likely than men to develop a frozen shoulder. There are numerous medical conditions that have been associated with adhesive capsulitis including diabetes, thyroid disorder, breast cancer treatment, heart attack, and stroke. In patients that develop a frozen shoulder there is a 50% probability of developing it in the other shoulder within two years.
People presenting with frozen shoulder typically complain of pain and loss of motion. The hallmark of frozen shoulder is loss of passive external rotation. Since not many things are done in positions of external rotation, most patients do not typically notice this loss and usually complain more of inability to reach behind their back, hindering their ability to fasten a bra or get to their wallet. Rotator cuff strength is typically normal. Although x-rays are usually normal, they can be useful in eliminating other causes of shoulder stiffness and loss of motion including arthritis, calcific tendonitis, or dislocation.
The mainstay of treatment of a frozen shoulder is conservative management. In fact, up to 80% of patients with this problem will improve thru the course of time itself and nothing further. Unfortunately, time can be in the realm of 1-2 years and most people typically grow frustrated early in the course of the process. The goal of the treating physician, therefore, is to first accurately make the diagnosis and then intervene with different modalities in effort to reduce the pain and shorten the disease duration. This may include the administration of a course of oral anti-inflammatories, intermittent steroid injections into the capsule (intra-articular), and/or physical therapy. The goal of therapy is gentle passive motion and avoidance of forceful manipulation which can make the condition worse. This can typically be done at home and rarely requires a formal physical therapist. In patients that don’t respond to conservative management, arthroscopic release of the capsule is generally advised if failure is demonstrated after 4-6 months.