Understanding Rotator Cuff Injuries

What is the shoulder rotator cuff?

The rotator cuff is a group of four muscles and their tendons that create a ‘cuff’ around the shoulder joint and centralise the humeral head in the socket. The bony anatomy can be compared to a golf ball on a tee and thus is not very stable on a stand alone basis. The rotator cuff has two functions that are to stabilise the shoulder joint but also to move it.

How does it work

The rotator cuff muscles are connected to the bone with tendons and stabilise the shoulder joint by ensuring that the head of the humerus sits within the socket. To allow the arm bone to glide easily, a lubricating sac called a bursa, separates the rotator cuff from the acromion, the bone at the top of your shoulder.

What happens

Rotator cuff pathology is really a continuum or a spectrum of abnormalities ranging from a normal, asymptomatic aging process to end-stage arthritis and instability caused by absence of the rotator cuff. Changes can vary from microscopic tears and bursitis to large tears. The symptoms include pain, weakness, restricted motion, a feeling of instability, catching, and locking.

When the strength or integrity of the muscles and tendons are compromised, control of the humeral head is impaired and the bursa and the tendons can become painful. If the space between the humeral head and the acromion is reduced then this is known as impingement. Impingements can result when rotator cuff muscles become irritated, swell and obstruct the space between the arm and shoulder bones, causing pinching and irritation to the tendons and bursa. The space can also be reduced by anatomical factors that then contribute to the tendons being irritated.

As we age, the rotator cuff tendons degenerate and can also undergo wear and tear as they rub between the acromion and the humeral head. When the bursa becomes irritated, this is known as bursitis.

It’s a bit of a chicken and egg scenario as to which of the factors come first.

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Who gets it

Rotator cuff injuries can occur at any age. In younger ages, it is typically secondary to trauma or from overuse especially in overhead activities (e.g. sports and overhead work) However everyone over 50 years of age has abnormalities in their rotator cuff, although usually asymptomatic, and the onset of symptoms may only be related to ordinary activities of daily living, or they can be attributed to a single event- fall or reaching behind etc

Tears of the rotator cuff are common. The prevalence of a rotator cuff tear has been reported to be 25% in those over 50 and 20% in those over 20 years of age. However only 1/3 of these tears are in pain.

What are the stages

While everyone’s presentation is individual there is a common continuum described in the absence of a traumatic injury.

The rotator cuff injury has been described as starting from normal tendons to an overloaded tendon with reactive tendinopathy ( acute) to tendon disrepair ( subacute to chronic)

Generally the repetitive, overuse or unaccustomed use (eg Play tennis after many years) can injure tendons and lead to pain and impaired function. This is called tendinitis, tendinosis or tendinopathy. People typically complain of shoulder pain at the tip of the shoulder and the upper, outer arm. The pain is often aggravated by reaching, pushing, pulling, lifting, positioning the arm above the shoulder level, or lying on the side. Painful daily activities may also include putting on a shirt or brushing hair. Sleeping maybe impaired.

Bursa involvement can add to the pain picture with night pain and upper lateral arm pain.

Progressing to a small partial thickness tear to degenerated tendons with large partial thickness tear or full thickness tear. Symptoms of significant rotator cuff tear nearly always include weakness as well as pain in the specific muscle-tendon unit. To present with a tear there are three main mechanisms 1.Trauma 2. Repetitive and 3. degenerative

Treatment

There are two basic options for treatment: conservative, non-surgical treatments and surgery.

Conservative Treatment

Treatment- of early stages reactive tendinopathy and partial tears are along similar principles.

For the best result treatment of a rotator cuff tendinopathy, it will require an individualised rehab program. Both to strengthen the rotator cuff but also to address any factors contributing to pain.

The first task when treating a torn rotator cuff is to identify the major factors that contributed to the injury. Based on the result of the examination, an individualized treatment plan is designed. Interventions may include:

• Ergonomic adjustments (eg, placing monitors, keyboards, and chairs at appropriate heights)
• Postural retraining – Education and training to improve sitting, sleeping, and standing postures
• Mobility/flexibility interventions – Exercises for the thoracic spine, scapulothoracic joint, glenohumeral joint, and cervical spine as needed to improve shoulder mechanics
• Strengthening and stability exercises to restore balance and coordination to the shoulder complex
• Treatment of any underlying pathological tissue with manual therapy or other modalities (may include: joint and soft tissue mobilization taping, ice/heat, nonsteroidal anti-inflammatory drugs [NSAIDs], injection, dry needling)

Our Physiotherapists utilise symptom modification techniques in their assessment to best guide which rehabilitation pathway will be best suited. Not each patient will present the same and therefore everyone requires individualised rehabilitation to ensure they get the best care possible.

Isometric exercises have been shown to be effective for immediate pain relief, as well as helping to build strength, so this is a common starting point. ‘Isometric’ means that the muscles are used with minimal movement of the sore joint, so they should be comfortable.

What’s Next?

Once pain has reduced, we start working on gradually loading the shoulder again, both with exercises and increasing day to day activities. Rehab needs to match activity levels and needs inline with the patient goals.

Research on partial thickness rotator cuff tears (< 75% tear of the muscle), has shown that physiotherapy is AS effective as surgery.

Conservative management has also shown to be effective in 73-80% of patients even with full-thickness rotator cuff tears and can reduce the need for surgery by up to 75% at a 2 year review.

Surgery

Surgery may be indicated for those with the following:

• Symptoms >6 months with conservative treatment
• Rotator cuff tears >3cms
• Significant weakness and loss of function

But Surgery is not a simple option

It takes the repaired rotator cuff tendons about six weeks to heal initially to the bone, three months to form a relatively strong attachment to the bone, and about six to nine months before the tendon is completely healed to the bone.

Some research has suggested that surgery may only be beneficial due to the fact that it enforces rest and a period of rehabilitation.