Frozen shoulder AKA Adhesive Capsulitis

Anatomy

The shoulder (glenohumeral) joint is comprised of the glenoid fossa of the scapula and the head of the humerus, which is surrounded by the strong connective tissue joint capsule. The glenohumeral joint is a ball and socket joint which provides the upper limb a significant amount of mobility and versatility.

Pathology Frozen Shoulder was originally thought to be an

inflammatory process, followed by fibrosis and contraction of the shoulder capsule.

It is also referred to as adhesive capsulitis, due to the belief that the capsule was adhering to the humeral head. However, its true pathology is still subject to debate. The condition causes significant pain and stiffness in the shoulder, with reductions in range, hence the name frozen shoulder.

There is still a poor understanding of the cause of frozen shoulder. Pathological changes have been noted such as thickening of the rotator interval, increased neovascularity, increased cytokine concentrations, contraction of the anterior and inferior part of the capsule, reduced joint volume, proliferation of fibroblasts and myofibroblasts and presence of contractile proteins.

There are also similarities with Frozen Shoulder and Dupuytren’s contracture with a high overlap between people suffering from these conditions.

Onset of frozen shoulder can be either idiopathic (unknown cause) or secondary, with secondary often following trauma and forced inactivity. Secondary onset falls into the following categories:

• Intrinsic causes à shoulder specific issues such as tendinopathies or after surgical intervention.

• Extrinsic à something occurs external to the shoulder, such as a humeral or clavicular fracture resulting in prolonged immobility.

• Systemic à Frozen shoulder develops in the presence of predisposing factors that affect the entire system such as diabetes, thyroid abnormalities and heart disease.

There are several risk factors for developing Frozen Shoulder which include:

• Diabetes

• Family history of frozen shoulder - Genetic predisposition.

• Hypothyroidism/hyperthyroidism

• Parkinson’s disease

• Cardiac disease

• Immobility or reduced mobility (such as those recovering from surgery or an injury).

The condition occurs more commonly in those between 40-60 years of age and is thought to affect women more than men. As the exact cause of frozen shoulder is unknown, prevention is difficult. In cases of forced immobility, regular passive range of motion exercises may reduce stiffness.

Symptoms of Frozen Shoulder

• Usually slow onset (but can also occur suddenly from acute trauma like a fall)

• High levels of pain in the shoulder

• Unable to sleep on affected side

• Painful and incomplete shoulder elevation and external rotation – restrictions tend to be in a capsular pattern (External rotation, Abduction and Internal Rotation are affected the most)

Progression of Frozen Shoulder

Frozen shoulder usually progresses through 3 phases:

1. Freezing phase – increase in pain more so than stiffness – length can be from 6 weeks to 9 months and will generally see a progressive reduction in range of movement.

2. Frozen or stiffness phase – pain decreases but range of movement remains restricted – can last 4-6 months to several years.

3. Thawing/recovery phase – slowly regaining range of motion – length from 6 months to 2 years.

The average duration for resolution is 30 months. Longer episodes of frozen phase are generally linked to longer thawing phases.

Treatment and management of Frozen Shoulder

Frozen shoulder improves with time but can take up to 30 months on average to resolve (with some reporting ongoing deficits and restriction in range of movement). Treatment surrounds controlling pain and slowing the rate of movement loss in the freezing phase, maintaining movement during the frozen phase and restoring motion and strength during the thawing phase.

• Supervised neglect is an option as it tends to self-resolve.

• Non-steroidal anti-inflammatory drugs can help to reduce pain and swelling.

• Mobilisations through the GHJ and exercise have shown some better outcomes (over ultrasound and massage).

• Short wave diathermy (heat) and stretching has shown some benefit.

• Heat or cold can be used, depending on what eases the pain.

• Maintaining range as able, within a pain free range, using passive, active assisted and active range of motion activities.

Medical options:

• Corticosteroid injections – cortisone is a powerful anti-inflammatory which is injected directly into the shoulder joint with lidocaine for pain relief. This may provide short to medium term relief – effective during the freezing phase.

• Hydrodistension procedures injects large volumes of sodium chloride into the capsule space to distend and stretch the capsule but has insufficient evidence to warrant recommendation.

• Manipulation under anesthetic (MUA) is another option where the joint is mobilized when the patient is under general anesthesia. The use of MUA is not supported by evidence and can result in iatrogenic damage following MUA, including haemarthrosis, SLAP lesions, partial thickness tears of the Rotator Cuff, osteochondral defects and labral detachment.

• Arthroscopic capsular release involves capsular distension, debriding, ligament splitting and loosening of adhesions. This procedure is currently not supported by clinical trials, but has been based on expert opinions and published case series.

So that’s an overview of frozen shoulder. If you have any questions or comments, please email us at admin@cbdwellnesscentre.com.au and we will be happy to answer them for you.

If you suffer from shoulder pain or ongoing restriction, feel free to call us on (08) 9486 8653 and our therapists will be happy to chat with you.