Frozen Shoulder (Adhesive Capsulitis)

The joint capsule (outer layer) is comprised of fibrous connective tissue that extends from the anatomical neck of the humerus to the outer rim of the glenoid. This capsule is formed by the superior, middle and inferior glenohumeral ligaments and it functions as the main stabiliser of the glenohumeral joint. The coracohumeral ligament, extending from the coracoid process to the greater tubercle of the humerus, supports the superior aspect of the joint; thickening of this ligament plays a role in the restricted range of movement in cases of frozen shoulder. The synovial membrane lines the inside of the joint capsule producing synovial fluid to reduce friction during movement.

Frozen shoulder typically presents with a gradual and progressive onset of pain and shoulder stiffness. Pain is commonly felt at the end of range of movement of the shoulder via the mechanism of stretching the capsule (Kelley et al., 2013). Pain can also be prominent at night.

The pain usually presents as a poorly localised deep ache, which may radiate down the anterior or lateral upper arm. Pain is associated with restricted active and passive range of movement at the shoulder. Initially, loss of external rotation (turning the arm out) is most common, followed by internal rotation, abduction and elevation (Dias et al., 2005). The pain and/or restriction results in increasing difficulties with functional activities such as hanging washing out to dry, drying/washing hair and doing up a bra.

Diagnosis of frozen shoulder is primarily made via clinical examination; however, imaging studies can be incorporated to exclude other shoulder conditions (Li et al., 2011).

The clinical criteria for the diagnosis of frozen shoulder includes (Kelley et al., 2013):

• Pain for at least one month;
• Pain at night;
• Inability to lie on the affected shoulder;
• Restriction in all passive and active ranges of movement;
• Pain is reproduced at the ends of the patient’s passive range of movement; and
• External rotation is most limited, particularly in adduction.

Imaging studies such as ultrasound (US) and magnetic resonance imaging (MRI) can identify coracohumeral ligament and joint capsule thickening, which is suggestive of frozen shoulder (Li et al., 2011). However, these signs may not be seen until later into the development of this condition (Yuan et al., 2017). Radiology is more useful in this condition to rule out the presence of other possible conditions, such as glenohumeral arthritis (Dias et al., 2005).

Current evidence suggests the most effective management for individuals with frozen shoulder is via a combination of medical and physiotherapy management (Cho, Bae, & Kim, 2019). Current evidence for medical management has demonstrated that hydrodilatation can provide significant improvement in individual’s pain and range of movement. This procedure involves the injection of saline solution and corticosteroid into the patient’s glenohumeral joint to help stretch the fibrous shoulder capsule (Cho et al., 2019). There is evidence that a combination of physiotherapy and hydrodilatation is most effective compared with either treatments in isolation (Cho et al., 2019). There is some evidence for the use of corticosteroid injections, however, the evidence suggests it is effective in reducing pain in the short-term but is no different than a wait-and-see approach in the long-term (Cho et al., 2019). CSI treatment seems to only be effective in the long-term in combination with physiotherapy management (Cho et al., 2019; Kelley, McClure, & Leggin, 2009). Though, the evidence suggests a more superior effect is seen in the use of hydrodilatation.

Physiotherapy management involves a combination of pain education, shoulder stretching and glenohumeral joint mobilisation techniques and home exercises (Chan, Pua, & How, 2017; Kelley et al., 2009; Kelley et al., 2013). Exercise programs vary enormously depending on the individual and their goals. For example, the exercise programs for people returning to recreational sport compared to those aiming to perform normal daily functions are understandably different. Though, most programs involve stretching exercises aimed at restoring capsular flexibility and shoulder range of movement (Kelley et al., 2009). Strengthening exercises may also be incorporated into the exercise regime as the surrounding muscles, e.g. the rotator cuff, often becomes weak due to prolonged periods of pain and reduced shoulder mobility.

Intervention may also be aimed at managing other regions that may become affected, for example, biomechanics of the scapula-cervical region are usually altered due to the limited glenohumeral (shoulder) range of movement, this may result in increases to the neck and upper back pain (Kelley et al., 2013).

In some cases of frozen shoulder, where there appears to be minimal to no resolution of movement restrictions over long periods of time, surgical intervention may be appropriate (Dias et al., 2005). A common procedure, which technically involves no surgery, is called manipulation under anaesthetic (Dias et al., 2005; Kelley et al., 2009; Kelley et al., 2013); this involves the forced movement of the shoulder to stretch and tear the capsule while the patient is under anaesthetic, in hopes to ‘kick-start’ improvements in therapy. Another procedure used is termed a ‘capsular release’ performed via arthroscopy. This operation involves the cutting and release of tight portions of the capsule (Cho et al., 2019; Dias et al., 2005); there are understandably more risks involved with this type of procedure, which is why it is usually utilised in cases failing other conservative forms of management.

Frozen shoulder can be a difficult diagnosis to make in the early stages, particularly when pain is the only presenting symptom. In the early stages, other possible conditions resulting in similar symptoms to frozen shoulder include (Ewald, 2011):

• Rotator cuff tendinopathy
• Glenohumeral osteoarthritis
• Subacromial or subdeltoid bursitis
• Cervical radicular pain
• Biceps tendinopathy
• Acromioclavicular arthropathy
• Autoimmune diseases e.g. rheumatoid arthritis
• Neoplasm

Once the multi-planar passive range of movement restrictions are apparent, the diagnosis becomes clearer, however, glenohumeral osteoarthritis can also result in similar symptoms and should be ruled out via x-ray (Ewald, 2011).

REFERENCES

Chan, H. B. Y., Pua, P. Y., & How, C. H. (2017). Physical therapy in the management of frozen shoulder. Singapore Med J, 58(12), 685-689. doi:10.11622/smedj.2017107

Cho, C. H., Bae, K. C., & Kim, D. H. (2019). Treatment Strategy for Frozen Shoulder. Clin Orthop Surg, 11(3), 249-257. doi:10.4055/cios.2019.11.3.249

Dias, R., Cutts, S., & Massoud, S. (2005). Frozen shoulder. BMJ, 331(7530), 1453-1456.

Ewald, A. (2011). Adhesive Capsulitis: A Review. American Family Physician, 83(4), 417-422.

Kelley, M. J., McClure, P. W., & Leggin, B. G. (2009). Frozen shoulder: evidence and a proposed model guiding rehabilitation. J Orthop Sports Phys Ther, 39(2), 135-148. doi:10.2519/jospt.2009.2916

Kelley, M. J., Shaffer, M. A., Kuhn, J. E., Michener, L. A., Seitz, A. L., Uhl, T. L., . . . McClure, P. W. (2013). Shoulder pain and mobility deficits: adhesive capsulitis. J Orthop Sports Phys Ther, 43(5), A1-31. doi:10.2519/jospt.2013.0302

Li, J. Q., Tang, K. L., Wang, J., Li, Q. Y., Xu, H. T., Yang, H. F., . . . Zhang, S. X. (2011). MRI findings for frozen shoulder evaluation: is the thickness of the coracohumeral ligament a valuable diagnostic tool? PLoS One, 6(12), e28704. doi:10.1371/journal.pone.0028704

Milgrom, C., Novack, V., Weil, Y., Jaber, S., Radeva-Petrova, D. R., & Finestone, A. (2008). Risk Factors for Idiopathic Frozen Shoulder. IMAJ, 10(5), 361-364.

Yuan, X., Zhang, Z., & Li, J. (2017). Pathophysiology of adhesive capsulitis of shoulder and the physiological effects of hyaluronan. European Journal of Inflammation, 15(3), 239-243.