What Causes Frozen Shoulder and How Can It Be Treated?

What Causes Frozen Shoulder and How Can It Be Treated?

Frozen shoulder, also known as adhesive capsulitis, is one of the more painful conditions that we see and treat at The Joint Injection Clinic. It is a condition which is characterised by pain, stiffness and significant restriction of range of movement of the ball-and-socket joint in the shoulder.

It is an unusual condition that can be triggered by even a minor injury or illness. No joint in the body undergoes the same process of severe restriction and then thawing to a complete (or at times almost complete) recovery, other than the shoulder. In frozen shoulder the capsule of the ball and socket joint ‘shrink wraps’ down on the head of the humerus (arm bone) leading to stiffness and loss of movement.

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With frozen shoulder the individual suffers a gradual and progressive loss of range of movement and stiffness in the ball-and-socket (glenohumeral) joint of the shoulder, which can make it very difficult to perform everyday tasks, such as washing your hair, reaching for a high shelf and fastening a bra behind the back. An initial trigger such as a minor injury or illness can result in a cascade of inflammation within the shoulder which leads to the formation of adhesions and subsequent gross restriction of range of movement. Patients often describe a minor trip or knock to the shoulder as a primary trigger. Other patients may have undergone an operation under general anaesthetic for an entirely different body part, i.e. a toe operation, but may have been placed in an awkward position on the operating table which puts stress on the shoulder, triggering the process.

The condition typically follows a three-stage pattern. At worst, each phase can last up to six months although these phases may be far shorter.

  • Freezing stage: This stage is characterised by a gradual increase in pain and stiffness in the shoulder. The pain may be worse at night and can make it difficult to sleep. The pain and stiffness typically develops over weeks to months and may have developed from a pre-existing issue such as “impingement” or rotator cuff injury. If a patient says that their symptoms came on over a few days then they almost certainly have another condition such as calcific tendinitis of the rotator cuff tendons or a form of nerve irritation.
  • Frozen stage: This stage is characterized by a reduction in pain but a continued restriction of range of movement. This phase is often reasonably well tolerated as the individual can now most likely sleep more comfortably and undergo daily activities with less pain but the shoulder may still feel very stiff and locked, and it may be difficult to reach overhead or behind the back. Day to day activities can still be very difficult and sports activity may still be unachievable during this phase.
  • Thawing stage: This stage is marked by a gradual return of movement. The pain and stiffness should slowly improve over time and the patient often regains a full and pain free range of movement. Most patients notice a slight restriction of range of movement that may persist for years or maybe even for ever, compared to the other shoulder but this is often barely noticeable and we would hope and expect most individuals to be able to achieve 90-95% of their normal range of movement and function levels.

Who is affected by frozen shoulder?

Frozen shoulder can affect all ages, but it is most common in people aged 40 to 60. It is also more common in women than in men. People with Type-1 (insulin dependent) diabetes, patients with a history of previous shoulder injuries, or individuals who have had to keep their shoulder immobilised for a period of time, i.e. after surgery or following an arm fracture, are at increased risk of developing frozen shoulder. Patients with type-1 diabetes also tend to be harder to treat as the degree of restriction and tightness in the capsule is far greater than in non-diabetic patients.

What are the main symptoms of frozen shoulder?

The main symptoms of frozen shoulder are:

  • Pain in the shoulder
  • Stiffness in the shoulder
  • Loss of range of motion in the shoulder

The pain may be felt in the shoulder itself or may radiate down the arm to the elbow or hand. The stiffness may make it difficult to perform everyday tasks, such as dressing, bathing, and reaching overhead.

How is frozen shoulder diagnosed?

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There is no one specific test for frozen shoulder. The diagnosis is usually made based on the patient's medical history and physical examination. The specific examination findings include restriction when placing hands behind the head, limitation of range of movement when reaching behind the back and limitation when attempting to raise the hands above the head. One of the classic signs is noted when the patient has their elbows tucked into their sides and bent to 90 degrees, with their forearms raised in front of them. In this position the patient is asked to rotate their shoulders and arms outwards (external rotation). With frozen shoulder we can expect the injured side to rotate far less than the non-injured side, indicating a likely diagnosis of frozen shoulder.

The doctor may order imaging tests, such as X-rays, ultrasound or MRI scans, to rule out other causes of shoulder pain. An x-ray may be used to rule out other causes of gross restriction of range of movement such as severe osteoarthritis of the ball and socket joint or in extremely rare cases a bony tumour within the joint.

On ultrasound assessment your doctor will be looking for excess fluid within the biceps tendon sheath and the ball-and-socket joint. Inflammation that develops during the frozen shoulder process results in excessive joint fluid which can be seen in these two locations. The doctor will also be checking to see that the rotator cuff tendons are intact and that there are no other significant injuries.

MRI is used to check on the above and will also allow the doctor to visualise the labrum, the rim of soft tissue cartilage, which helps to deepen and stabilise the ball and socket joint. The labrum acts like a toilet-plunger, sucking the ball (head of the humerus) into the socket and can become injured and potentially mimic or worsen a frozen shoulder.

How is frozen shoulder treated?

Treatments aim to relieve inflammation, pain and improve function. Treatment options may include:

  • Pain relievers: Over-the-counter pain relievers, such as ibuprofen, paracetamol, codeine or naproxen, can help to relieve mild to moderate pain. Prescription pain relievers may be necessary for people with more severe pain.
  • Physiotherapy: Physiotherapy aims to help patients to improve their shoulder range of motion and strengthen the muscles around the shoulder.
  • Corticosteroid injections: Corticosteroid injections can help to reduce inflammation and pain in the shoulder joint.

Corticosteroid injections can be a highly effective way of reducing inflammation and pain associated with a frozen shoulder. The two main injection options include:

  • a standard injection of steroid and local anaesthetic to the ball-and-socket joint under ultrasound-guidance if pain (and not range of movement restriction) is the predominant feature. A total volume of 5-10mls is injected and can have a dramatic impact on pain, helping the patient to start to work on their range of movement and allowing them to move the shoulder more comfortably during the day and make sleep more bearable. The effects of the injection may be noted within days but can take several weeks to really kick in. Side effects are rare but include a 1 in 10,000 risk of localised infection, bleeding and nerve damage. If the patient has insulin-dependent diabetes then the steroid can interfere with the action of the insulin and push their blood sugar levels up. Patients are therefore advised to check their blood sugars frequently and have a plan to manage raised sugars if they develop this in the days following the injection.
  • a Hydrodilatation procedure describes an injection of a larger volume of fluid consisting of steroid, local anaesthetic and water or saline. This is injected under ultrasound-guidance to the ball-and-socket joint as a way of mechanically stretching the tight capsule, responsible for limiting the range of movement in frozen shoulder. This injection is used when the range of movement is significantly restricted. A total volume of 10-40mls of fluid is injected following administration of local anaesthetic, which is placed between the skin and the joint. The procedure is performed in a side-lying position. Patients may feel a stretching tightness or pressure build up within the shoulder and sometimes describe a “dead arm” feeling, as if they have been punched in the shoulder. This is generally short lived and settles rapidly after the procedure.
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At The Joint Injection Clinic, these injections are performed after a thorough consent process, whereby the risk and benefits of the procedure are discussed in detail with your doctor. The experienced medical doctor will then place you in a side-lying position with the affected shoulder upmost and with the hand of the affected shoulder placed on the opposite side of the chest. The shoulder is cleaned using a cleaning solution to ensure that the procedure is performed under sterile conditions. Local anaesthetic is injected from the skin to the joint under ultrasound guidance. After giving the local anaesthetic a few minutes to take effect, the standard shoulder joint injection or hydrodilatation procedure is performed with a small dose of steroid and local anaesthetic (and sometimes water/saline), targeting the back part of the ball and socket joint.

The injection itself is normally completed within 30-60 seconds (3-5 minutes for the hydrodilatation procedure), after which a plaster is applied and post-injection advice is given. The patient is advised to look out for any signs of infection, specifically to check whether the local area becomes red, hot, tender, swollen or if they develop a fever. If this occurs then the patient is asked to contact the clinic immediately at which time a formal reassessment will occur and if needed oral antibiotics can be prescribed. The patient is also warned that following any injection they may notice a short-term worsening or flare in their symptoms after the local anaesthetic has worn off (4-5 hours). This may last for 3-5 days and the patient is advised to consider icing of the area using an ice pack for 10-15 minutes every hour as required.

At The Joint Injection Clinic patients are then advised to seek the guidance of an expert musculoskeletal physiotherapist, who can help them to work on optimisation of range of movement, strengthening and return to normal daily activities. As standard, the patient is then followed up at 4 weeks to check on progress and ensure that the treatment has helped.

  • Manipulation under anaesthesia: This procedure involves manually moving the shoulder joint under anaesthesia to break up scar tissue and improve range of motion. In our experience this is very rarely required.
  • Surgery: Surgery is rarely necessary for frozen shoulder. However, it may be an option if all other treatments have not been effective.

Most cases of frozen shoulder resolve on their own within 1 to 3 years. However, treatment can help significantly to relieve pain and improve function during this time. If you are experiencing pain and stiffness in your shoulder, it is important to see a doctor to obtain a diagnosis and discuss all the treatment options.