Adhesive Capsulitis, commonly known as frozen shoulder, is a condition demarcated by pain, as well as, progressive stiffness and loss of motion in the shoulder joint due to thickening and tightening of the shoulder capsule.
When we talk about the shoulder capsule, we are referring to the glenohumeral articular capsule, that gives the joint stability whilst allowing freedom of movement. It is a fibrous sheath that completely covers the glenohumeral articulation. This sheath runs from the neck of the humerus (arm bone) to the glenoid cavity of the scapula (concave joint surface of the shoulder blade forming the socket). The joint capsule is reinforced by the ligaments in the area, namely the glenohumeral ligaments and the coracohumeral ligament. The rotator cuff tendons also contribute to the strength and stability of the capsule as their tendons blend and merge with the capsule.
The interior surface of the fibrous capsule is covered by the synovium or synovial membrane. The synovial membrane produces synovial fluid that serves to lubricate the joint and reduces friction of the movement of this joint. It also forms synovial bursas, which are fluid filled sacs that also serve as cushions to reduce friction. Frozen shoulder may affect these structures as well.
The cause of frozen shoulder is unknown, but it is believed that injury and/or inflammation to the area causes the capsule to scar, thicken and contract, which then leads to the decreased Range of motion (ROM) of the shoulder joint from which we get the name of the condition.
Onset of the condition may be:
Primary – idiopathic (starts on its own, without any identifiable cause).
Secondary – caused by a known factor or predisposing factor.
Predisposing factors include:
- Trauma to the area
- Systemic or metabolic conditions such as Diabetes Mellitus, thyroid disease
- Rheumatic conditions
- Injury such as: arthritis, fractures, rotator cuff injuries, tendinopathies
- Auto-immune diseases,
- Some cancers and/or cancer treatments, i.e. breast cancer
The most common complaint is a sudden onset of pain in the shoulder, that becomes progressively worse, followed by progressive decrease in the ROM of the shoulder. The main component of ROM affected being external rotation (rotating the arm bone outwards). The condition is commonly described in 3 phases below, however, there is disagreement in literature about the duration of each phase and their demarcations.
- Painful or Freezing Phase
This phase is marked with pain in the shoulder, that increases with movement especially at the extremes of ROM. Pain is worse at night and may wake a person up from sleep. Night pain is a common sign of inflammation and it is believed that the pain limits people’s use of the arm. This pain along with the contraction of the capsule contributes to the “freezing” or decrease in ROM of the shoulder. This stage may last anywhere from 2 to several months.
- Adhesive or Frozen Phase
In this stage there is progressive decrease of the ROM of the shoulder due to the contraction of the capsule. The capsule is thick with adhesions and scarring which stiffen the joint. The decrease in ROM follows the capsular pattern which is decrease in external rotation, then in abduction, and then in internal rotation. The pain in this stage starts to decrease significantly, and in some cases, can only be felt at the extremes of the available range. This stage may last anywhere from a few months to a year.
- Resolution or Thawing Phase
The ROM of the shoulder starts to improve gradually and return to normal. Some people recover completely, some may take years to fully recover, while others never regain the full ROM of what they had before they had the condition. This process may take months to many years.
When dealing with Frozen shoulder it is important to monitor the symptoms closely, as the pain and lack of sleep may lead to depression. Depression in turn, may exacerbate the symptoms, thus creating a vicious cycle.
The diagnosis is highly dependent on the stage of the condition. The diagnosis is highly dependent on a process of elimination of different conditions that may cause pain in the shoulder, especially in the first phase. A diagnosis is made with the following factors in mind:
- The history of the patient to shed light into predisposing factors.
- Pain: severity and behaviour of the pain, especially night pain and relationship with different movements and positions.
- ROM (active and passive): identify the movements that are affected and especially if they follow the capsular pattern. It is important to note that some cases do not follow this pattern.
- Postural and movement analysis.
- Integrity of the ligaments and muscles, especially the rotator cuff in the area.
There are some special tests used to assess some of these components. Imaging is generally not indicated, although in some cases, these techniques may be used, such as X-rays to rule out other conditions including arthritis. MRI or arthrograms can be used to assess the joint integrity, fluid within the synovium and even ultrasound to assess the surrounding soft tissues. Your healthcare practitioner may consider sending you for some lab tests to check for underlying diseases as these may be predisposing factors but none of these test specifically for adhesive capsulitis.
The general management of this condition involves a combination of non-steroidal anti-inflammatory drugs (NSAIDs) and physiotherapy.
The physiotherapy interventions vary according to the stage of the condition.
- In the Freezing phase: the main focus of this phase is to decrease pain and inflammation. Modalities such as heat, ice or combination therapy, TENS (Transcutaneous Electrical Nerve Stimulation), taping and even dry needling have shown to work. These are combined with gentle mobilisations and exercises to assist with the loss of ROM. It is important to avoid activities that cause pain during this phase.
- In the Frozen phase: the main aim is to regain some ROM. Joint mobilisations, stretches, specific muscle strengthening, and retraining are the main methods used to regain ROM. Dry needling may be used as an adjunct as well as MWM (Mobilisations with movement). Care needs to be taken not to push too hard and cause inflammation in this stage.
- Resolution phase: the main objective of this phase is maintaining the ROM gained and to continue increasing ROM back to full ROM (where possible). In this stage there is also focus in correct muscle recruiting patterns and stability.
Other interventions include: Injections, arthroscopic release and manipulation under anaesthesia. When non-operative options fail, some patients may then consider surgery.
Frozen shoulder is somewhat mysterious in the way it starts and how it progresses. It is important to be educated on its different stages and to monitor symptoms as they progress. It is very important to have a good cooperative relationship with your healthcare practitioner to yield the best results.
We hope you found this helpful. Feel free to drop us a question if you have any queries or would like assistance pertaining to this condition.