What and How for Frozen Shoulder

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The Mechanism Behind Frozen Shoulder (Adhesive Capsulitis)

Frozen shoulder, also known as adhesive capsulitis, most often occurs between the ages of 40 to 60. Frozen shoulder is progressive shoulder pain and stiffness that can often limit or hinder activities of daily living. Understanding the underlying mechanism can help patients appreciate the importance of early intervention and active treatment.

What Happens in a Frozen Shoulder?

The primary issue in frozen shoulder is inflammation and fibrosis (thickening and scarring) of the shoulder joint capsule, which is the connective tissue around the glenohumeral (shoulder) joint.

The condition typically develops in three stages:

1. Freezing Stage (Painful Stage)

In this first phase, inflammation has initiated in the joint capsule. Patients report the gradual onset of pain, notably during the night, or when attempting particular movements. This discomfort leads to increased difficulty in moving the shoulder due to pain, along with the initiation of stiffness.

2. Frozen Stage (Stiff Stage)

If inflammation continues, the capsule becomes thicker and tighter, and adhesions (scar tissue) develop between the layers of the capsule. At this time, motion is highly restricted, but the pain may be less than the previous stage.

3. Thawing Stage (Recovery Stage)

Eventually, the inflammation resolves and the capsule tissue begins to loosen, and mobility will gradually improve. Recovery can take a few months to a few years, depending on how early on and well the problem is addressed.

Genetic Factors and Frozen Shoulder: Is There a Link?

Although the precise mechanisms underlying frozen shoulder (adhesive capsulitis) remain poorly understood, peer-reviewed research does suggest that genetic predisposition may have a role in the development of frozen shoulder. The current evidence is limited, but there are some interesting findings to consider.

Genetic Connections to Frozen Shoulder

  • Family History: Certain research has shown an increased incidence of frozen shoulder in those with a family history of the disease. This suggests a potential inherited predisposition. (1, 2)
  • Connection to Diabetes: There is a much higher prevalence of frozen shoulder in patients with diabetes, and diabetes itself has a hereditary component. Heredity may play a role in the development of frozen shoulder due to a metabolic mechanism. (3, 4) According to the research from Zreik et al., the prevalence of frozen shoulder in diabetic individuals is 5 times higher than in non-diabetic individuals.
  • Connective Tissue Disorders: Some hereditary connective tissue disorders may confer a higher risk of adhesive capsulitis, possibly indicating a shared genetic mechanism. (5, 6)

Treatment Options for Frozen Shoulder (Adhesive Capsulitis)

Frozen shoulder treatment focuses on two main goals:

  1. Reducing pain, and
  2. Improving shoulder mobility (range of motion).

Treatment is tailored to the stage of the condition and the severity of symptoms.

Conservative Management

πŸ’Š Medications

  • NSAIDs (e.g. ibuprofen, naproxen): Help reduce inflammation and pain.
  • Oral corticosteroids: May be used short-term for severe pain during the early inflammatory phase.
    β†’ These help with symptoms but don’t address the underlying joint stiffness.
  • Stretching & Physical Therapy
  • Home exercises: Pendulum swings, towel stretches, wall walks.
  • Physiotherapy: Guided sessions to improve range of motion using passive and active movements.
  • Heat/Ice Therapy
  • Ice packs: Helpful during the painful (freezing) phase to reduce inflammation.
  • Heat packs: Useful in later stages to relax muscles and improve blood flow.

πŸ’‰ Medical Interventions

  • Corticosteroid Injections (7)
    • Injected directly into the shoulder joint capsule to reduce inflammation.
    • Most effective during the early “freezing” stage.
    • Can accelerate symptom relief but is not always curative.
  • Hydrodilatation (Capsular Distension) (8)
    • A procedure in which saline and corticosteroid are injected into the joint to stretch the capsule and break adhesions.
    • Often guided by ultrasound or fluoroscopy.

Effectiveness of Physical Therapy

  • Research indicates that physiotherapy significantly improves shoulder mobility and reduces pain in most cases. (9)
  • Techniques such as passive joint mobilization, active stretching, and strengthening exercises are especially effective. (9)
  • Physical therapy is most beneficial during the frozen and thawing stages of the condition. (9)
  • Several studies report that more than 70% of patients experience functional improvement within 6 months of beginning physical therapy. (10)
    However, results vary based on:
    • The stage of the condition at treatment onset
    • Consistency with rehabilitation
    • Individual response to therapy

Reference

  1. Kelley, M. J., Shaffer, M. A., Kuhn, J. E., Michener, L. A., Seitz, A. L., Uhl, T. L., … & McClure, P. W. (2013). Frozen shoulder: A review of current concepts. Journal of Shoulder and Elbow Surgery, 22(3), 469–478. https://doi.org/10.1016/j.jse.2012.11.011
  2. Urwin, M., Symmons, D., Allison, T., Brammah, T., Busby, H., Roxby, M., Simmons, A., & Williams, G. (2011). Genetic factors in musculoskeletal disorders. Best Practice & Research Clinical Rheumatology, 25(6), 703–714. https://doi.org/10.1016/j.berh.2011.11.004
  3. Zreik, N. H., Malik, R. A., Charalambous, C. P. (2016). Adhesive capsulitis of the shoulder and diabetes: A meta-analysis of prevalence. Journal of Shoulder and Elbow Surgery, 25(5), 754–761. https://doi.org/10.1016/j.jse.2015.08.045
  4. Wang, K., Ho, V., Hunter, D. J. (2017). Adhesive capsulitis and diabetes: A population-based cohort study. The Journal of Rheumatology, 44(6), 814–820. https://doi.org/10.3899/jrheum.160972
  5. Reeves, B. (1995). The pathology of frozen shoulder. A Dupuytren-like disease. The Journal of Bone and Joint Surgery. British Volume, 77(5), 677–683.​
  6. Raykha, C. N., Crawford, J. D., Burry, A. F., Drosdowech, D. S., Faber, K. J., Gan, B. S., & O’Gorman, D. B. (2014). IGF2 expression and Ξ²-catenin levels are increased in Frozen Shoulder Syndrome. Clinical and Investigative Medicine, 37(4), E262–E267.
  7. Koh, K. H. (2017). Corticosteroid injection in adhesive capsulitis: A systematic review and meta-analysis. The American Journal of Sports Medicine, 45(9), 2228–2236. https://doi.org/10.1177/0363546516688042
  8. Poku, D., Hassan, R., & Migliorini, F. (2023). Efficacy of hydrodilatation in frozen shoulder: a systematic review. British Medical Bulletin, 147(1), 121–136. https://doi.org/10.1093/bmb/ldad018
  9. Kelley, M. J., Shaffer, M. A., Kuhn, J. E., et al. (2013).
    Frozen shoulder: A review of current concepts. Journal of Shoulder and Elbow Surgery, 22(3), 469–478.
    https://doi.org/10.1016/j.jse.2012.11.011
  10. Page, M. J., Green, S., Kramer, S., et al. (2014).
    Manual therapy and exercise for adhesive capsulitis (frozen shoulder). Cochrane Database of Systematic Reviews, (8), CD011275.
    https://doi.org/10.1002/14651858.CD011275