Frozen Shoulder: Thawing the Sticky Mystery of Adhesive Capsulitis

Frozen Shoulder and Adhesive Capsulitis are both conditions that ultimately involve significant stiffness and restriction in both active and passive motion of the shoulder. The diagnosis is clinical, meaning it is primarily made based on the history and examination, and when there is not a clear initiating factor, idiopathic, it is reached when all other possibilities are excluded. The picture isn’t so simple, however, because there are literally hundreds of disorders or other diagnoses that can contribute or initiate the cascade of events that lead to a frozen shoulder. A frozen shoulder can also coexist with other entities, meaning patients may present with both a rotator cuff tear and frozen shoulder, for example.

It’s perplexing and murky nature was first recognized by Dr. Codman who aptly termed frozen shoulder as “difficult to define, difficult to treat and difficult to explain from the point of view of pathology.” In 1945, Neviaser coined the term adhesive capsulitis and described the pathological lesion of fibrosis, inflammation, and capsular contracture responsible for idiopathic frozen shoulder. Others have supported this description – histological analysis consistently demonstrates chronic nonspecific inflammation with synovial hyperplasia, proliferation of vessels and fibroblasts, and increased amount of extracellular matrix. Some have also highlighted the generally reduced level of synovial fluid, joint lubrication, found at different stages of adhesive capsulitis. To date, despite nearly a century of research, the root cause of frozen shoulder and adhesive capsulitis remain unknown.

Several researchers have suggested the likelihood that there may be an autoimmune and/or genetic component, whereby patients with a predilection or susceptibility to developing a frozen shoulder, only do so when a particular environmental or systemic trigger is encountered-setting in motion a complex cascade of events that ultimately lead to adhesive capsulitis (frozen shoulder). This may help explain why patients with systemic diseases involving the endocrine system (hormones), such as diabetes and thyroid disorders, are at much greater risk for developing frozen shoulder.

SYMPTOMS

Gradual onset of pain at the lateral part of the arm (deltoid insertion, rather than at the shoulder joint, is the most common presenting complaint. Typically the pain is achy at rest and much sharper with movement, especially sudden or high-speed movements. Pain at night with sleep disturbance is also a very common complaint. With more advanced stages of adhesive capsulitis, shoulder stiffness or restricted range of motion becomes more apparent-inability to fasten bra behind back, reach back for seatbelt, or tuck in shirt, for example. These are understandably rather nonspecific complaints, meaning many other causes of shoulder pain can also present with these complaints, so the presence of one or more of these doesn’t mean you have a frozen shoulder-there may be other causes or you may have several causes all at once.

DIAGNOSIS

The diagnosis of frozen shoulder is clinical, meaning your doctor will perform a detailed evaluation to provide you with a comprehensive diagnosis. For instance, in our practice, the majority of patients referred with persistent or severe frozen shoulder have other contributing diagnoses, such as a pinched nerve, rotator cuff tear, labrum tear, etc.

TREATMENT

The goals of treatment are ultimately to reverse the inflammation, restore the elasticity, motion, and function of the shoulder, and most importantly remove the pain. Many different treatments have been recommended over the years, with varying levels of success.

Oral anti-inflammatory drugs such as NSAIDs (aspirin, ibuprofen, indomethacin, naproxen, etc.) have not been shown to be very effective in helping restore motion, but are commonly used to help with temporary pain relief. The studies looking at NSAIDs for frozen shoulder also report that side effects such as nausea are common with these drugs.

Oral anti-inflammatory steroids such as prednisone or a Medrol Dosepak show a more rapid relief of pain in studies, but unfortunately this effect is short-lived. The potential for systemic side effects, such as aseptic necrosis, and the inconvenience of daily dosing are disadvantages of systemic treatment.

Intra-articular steroid injections have been extensively studied and have been shown to offer a rapid improvement in pain with benefit for motion and function more likely in the early phases of adhesive capsulitis, before severe motion restriction is present.

Physical therapy is commonly prescribed for frozen shoulder, but most studies seem to indicate the best physical therapy involves using low grade mobilization techniques with gentle stretching within the patient’s pain threshold rather than high grade mobilization techniques and strenuous active and passive stretching beyond the pain threshold. This gentle form of physiotherapy has sometimes been called “benign neglect” in that the goal is to promote gradual restoration of active and passive motion and function rather than the more typical “no pain no gain” protocols commonly seen. In our experience, significant muscular spasm and changes in muscle-tendon flexibility are also present in these patients and low-grade mobilization techniques, including newer methods like proprioceptive neuromuscular facilitation (PNF), active stretch, and co-contraction, can help improve proprioception and muscular relaxation more effectively than the strenuous high-grade techniques.

Frozen Shoulder refractory to these conservative measures has historically been treated with manipulation under anesthesia. Complications of this technique have been reported including humeral fracture, rotator cuff rupture, labrum tears, and injury to the biceps tendon.

PREFERRED APPROACH

Our preferred approach for the early stages of adhesive capsulitis is an intra-articular steroid injection combined with a gentle shoulder mobilization program. For patients without concurrent pathology or other mitigating factor, this approach provides a high level of satisfaction and success for both the patient and physician.

Refractory frozen shoulder and adhesive capsulitis are best addressed in our hands with an all-arthroscopic approach. As many of these patients have concurrent or contributing pathology, we prefer the anatomic precision and accuracy of an arthroscopic capsulotomy, which also allows us to evaluate and treat concurrent pathology. After the arthroscopic procedure patients are immediately started on a gentle mobilization program to overcome the significant muscular contraction/spasm that is typically present. This low slow approach to regaining mobility still requires significant patient commitment, but ultimately provides our patients with a predictable path to pain relief and functional restoration.

CONCLUSION

Frozen shoulder and adhesive capsulitis are still without a clear known cause. Research continues on agents, such as hyaluronic acid for example, to short circuit the inflammatory cascade, inhibit scar deposition and enhance capsular remodeling but none have yet been approved for clinical use. Treatment starts with first clearly establishing a comprehensive diagnosis followed by a treatment regimen tailored to each patient. Arthroscopic capsulotomy, in our hands, has become the treatment of choice for patients with refractory severe adhesive capsulitis and frozen shoulder. More information is available at TheShoulderCenter.com