Rotator Cuff Injury

The rotator cuff is a group of four muscles with tendons that attach to the humeral head. They contribute to the stability of the shoulder and play a large role in raising the arm. The rotator cuff tendons may be torn or bruised by a traumatic event, such as a fall on an outstretched hand. However, many rotator cuff injuries are due to overuse. Many repetitive activities, especially overhead activity, such as throwing, tennis or swimming, put a great deal of stress on the rotator cuff. Eventually, the tissues can breakdown and tear. This can result in pain, loss of strength, or loss of range of motion, all of which can result in loss of function. Although rotator cuff tears are a common cause of shoulder pain, less than 5% of patients will actually need surgery. Nonoperative treatment with a guided exercise program and a gradual and controlled return to activities can successfully treat overuse rotator cuff tears. Additionally, rotator cuff tears become more common as patients age, but most are “silent”, meaning that patients are able to perform 100% of their activities without shoulder pain or limitations, as their bodies have been able to adjust by using other muscles. Our goal is to help patients return to their functional baseline with the least invasive treatment option.

Anatomy

The shoulder is one of the most complex joints in your body and allows your arm to rotate and move in many different directions. The shoulder joint is described as a “ball and socket” joint, however, the socket is very shallow and is similar to a golf ball resting on a tee. The shoulder is made up of three bones: the humerus (upper arm bone), the clavicle (collarbone), and the scapula (shoulder blade). The outer portion of the scapula bone is called the glenoid and is the golf tee where the ball of the humeral bone rests to make up the shoulder joint. The shoulder joint is also called the glenohumeral joint and you may see it referred as this in test results.

Due to the geometry of the shoulder joint, it is very flexible and allows a large range of motion, but this leads to an inherent risk of injury to the shoulder. Several soft tissue structures (non-bony structures) exist in the shoulder joint to improve the stability of the joint.

• Labrum: A rim of cartilage on the shoulder socket (glenoid) that helps stabilize the joint by providing a bumper for the ball around the socket.

• Capsule: Every joint has an envelope around it to contain the joint and the joint fluid.

  • Ligaments: Several ligaments in the shoulder joint strengthen the capsule and increase stability of the shoulder joint

• Rotator cuff muscles: A group of 4 muscles that are an important contributor to shoulder stability and function. Each muscle attaches to the humeral head (ball of the shoulder joint) and work in a coordination fashion to keep the ball centered in the socket

  • The subscapularis is a large rotator cuff muscle that attaches to the front of the ball and allows you to rotate your arm inward

  • The supraspinatus and infraspinatus muscles attach at the top of the ball and allow you to raise your arm overhead

  • The teres minor attaches to the back of the ball and allows you to rotate your arm outward

Other soft tissue structures in the shoulder include:

• Bursa: These structures are located between bone and the surrounding soft tissue above the rotator cuff. They serve as a cushion between the rotator cuff and the bones of the shoulder

• Cartilage: This structure is present in all joints, where its called articular cartilage, and covers both ends of the bones in the joint. Cartilage allows the bones to glide easily as the joint is moved.

Rotator Cuff Injury

Rotator cuff injuries are very common and can result from a specific acute injury or from chronic irritation. When the rotator cuff is injured, it is usually the tendons that are injured and the muscle is spared. Injury can range from a mild strain and irritation to a large tear involving several rotator cuff tendons. Typically, the severity the injury dictates the level of pain and dysfunction. However, some patients can have relatively large tears without much pain or functional limitation. 3 types of rotator cuff conditions exist:

• Tendinitis happens when the rotator cuff tendons become inflamed as a result of overuse or overload. This commonly results from repetitive overhead activities that occur during sports and/or activities of daily living.

• Bursitis is an inflammation of the fluid-filled sac (bursa) between the rotator cuff and the bone above it (acromion) that happens when it becomes irritated. This can also result from overhead activity or overuse of the shoulder.

• A tear of the rotator cuff can occur from an acute injury or over time if tendinitis and bursitis are not treated. Acute tears are due to a specific injury like falling down onto an outstretched arm or lifting an object that was too heavy. Degenerative/chronic tears happen over time because the tendon has been slowly worn down and is more common as we get older. Rotator cuff tears can be partial, where only part of the tendon is injured, or complete/“full-thickness”, where the connection between the tendon and the bone has been disrupted.

Risk Factors for Injury

Rotator cuff tendon tears can occur for several reasons. Risk factors for injury include age, repetitive overhead movements, or bone spurs above the rotator cuff tendons. As we get older, the normal blood supply to the rotator cuff tendon and the overall quality of the tendon tissue decreases making it more vulnerable to injury. Additionally, bone spurs on the underside of the acromion bone, which forms a roof over the rotator cuff tendons, can cause impingement of the rotator cuff tendon against the bone as you raise your arm.

Symptoms

The most common symptom of a rotator cuff tendon injury is pain, particularly with overhead activities. Patients may also have pain with reaching behind the back. Pain at night is also common and can wake you from sleep, especially if sleeping on the affected shoulder. The pain can be located in different locations, based on the patient, and may manifest deep in the shoulder, on the outside of the shoulder, or the front of the shoulder. Patients may also sense a weakness in the shoulder when lifting objects.

Diagnosis

Rotator cuff tendon injuries are diagnosed using physical examination and imaging studies to confirm the diagnosis. The physical examination is used to identify areas of pain, weakness, and changes in range of motion of the shoulder. X-rays help evaluate for the presence of a bone spur or any arthritic changes of the shoulder joint. MRI (magnetic resonance imaging) allows us to evaluate the soft tissue and non-bony parts of your shoulder and specifically look at the integrity of the rotator cuff tendons. MRI will provide information about rotator cuff tears such as the size, length of tendon retraction, and tear shape, which can influence treatment selection and will help determine the prognosis. 

Treatment

Treatment of rotator cuff tendon injuries can be done with non-surgical or surgical means. The goal of treatment is to reduce pain and regain function of the shoulder. Non-surgical treatment is used for patients with slowly developing mild to moderate rotator cuff tendon injuries due to overuse. These therapies are used to reduce inflammation associated with injury and allow you to strengthen the rotator cuff muscles and regain function. Non-surgical treatment options include:

• Rest

• Change in activities: Avoiding activities that irritate the shoulder, specifically overhead motions

• Non-steroidal anti-inflammatory medications (NSAIDs) can help decrease inflammation

• Injections: Steroid injections can help decrease inflammation in the bursa surrounding the rotator cuff tendons, but should be used sparingly. Steroid injections can be used if rest, activity modification, and NSAIDs do not improve the symptoms. There is currently little evidence supporting the use of biologic injections for rotator cuff tendon injuries, but this is an area of increased scientific study.

• Physical therapy: This is an important tool to help you strengthen and retrain the muscles of the rotator cuff to work better together

Moderate injuries of the rotator cuff that do not improve with conservative care and severe injuries to the rotator cuff or acute injuries may need surgery to return you to the activities you love. Surgical options include:

• Arthroscopic Rotator Cuff Repair is the most commonly performed surgery to fix a torn rotator cuff back to bone. This is the most minimally invasive technique available. Dr. Kew uses a specialized camera and set of small instruments through a series of small incisions in the skin around your shoulder to repair the torn tendons back to the arm bone (humerus) where they normally insert. Using arthroscopic techniques minimizes the surgery time, blood loss, and postoperative pain. Recovery time is typically 4 months, but depends on many factors such as tear size, the quality of the tissues, and level of activity.

  • Good candidates for arthroscopic rotator cuff repair include:

• Symptoms that have lasted 6 to 12 months or longer

• Large tears(more than 3 cm) and the quality of the surrounding tissue is healthy

• Significant weakness and loss of function in the shoulder

• The tear was caused by a recent, acute injury.

• Open Rotator Cuff Repair is sometimes undertaken for very large tears of the rotator cuff that cannot adequately be treated by arthroscopic means. Before the advent of arthroscopic techniques, all rotator cuff tears were repaired in this fashion. An incision is made in the skin and the large muscle on the outside of the shoulder (deltoid) is split to allow the surgeon to see and repair the rotator cuff. Today, open repairs of the rotator cuff are very uncommon and reserved for very difficult tears.

• Tendon Transfer is when a tendon from a different muscle, with the same basic job of the rotator cuff, is moved to take the place of an irreparable rotator cuff tendon. This may be used in rare cases for patients with massive rotator cuff tendon tears that are not repairable. In this procedure, we move a tendon from one location to another location to help regain some of the function lost by the rotator cuff. This is often a last step or a salvage type of surgery.

• Reverse Total Shoulder Replacement is another type of salvage surgery that is most commonly performed in patients with both rotator cuff tear and severe arthritis of the shoulder. The procedure is designed to replace the arthritic shoulder with metal and plastic implants and allow another large muscle in your shoulder, the deltoid, to move the shoulder joint.