Rotator Cuff Injections

Shoulder injections to treat rotator cuff injuries typically target the small space between 2 bones:

• The bottom of the acromion (the top outer edge of the shoulder blade)
• The top of the shoulder’s ball-and-socket joint (glenohumeral joint)

This space is called the subacromial space and the injections are called subacromial injections.

Rotator cuff tendons travel through this small space, where degeneration and impingement often occur.

Goals of Injection Treatments

Subacromial injections have some combination of the following goals:

• Manage pain, swelling, and inflammation
• Facilitate participation in physical therapy and exercise
• Improve range of motion in the shoulder
• Improve healing in the injured muscles and tendons

Through these potential benefits, the injections aim to help the patient better tolerate daily activities and improve the quality of life.

Common injection treatments are discussed below.

Corticosteroid Injection

Cortisone, a type of corticosteroid, helps relieve inflammation, and the medication is sometimes combined with a local anesthetic for additional pain-relieving effects.

These injections offer pain relief for days, weeks, or even months, but do not directly improve healing of the muscle or tendon tissue.

Platelet Rich Plasma (PRP)

PRP harnesses the body's healing potential. Platelets are extracted from the patient’s blood, concentrated, and then injected into the subacromial space. The goal of a PRP injection is to stimulate tissue healing by reducing inflammation, encouraging the growth of new tissue in the joint, and regulating the body’s immune function.

See Pros and Cons of Using PRP for Tendon Injuries

Prolotherapy

This treatment involves administering small amounts of a medicated solution, such as dextrose or saline, into the rotator cuff tissue(s) over a period of several weeks with the goal of inducing tissue regeneration, promoting healing, and reducing pain.

Stem Cell Injection

Stem cells have the ability to transform into different cell types and regrow different types of tissues. Similar to PRP, the goal of this injection is to promote healing and regeneration of damaged tendons or muscles, potentially offering a long-term solution.

See Stem Cell Therapy for Sports Injuries

Effectiveness of Rotator Cuff Injections

The injections offer varying degrees of effectiveness, and every individual responds differently to the injection.

• Some people experience a significant decrease in their symptoms, while others may find only slight improvement.
• The duration of pain relief may last for a few days, weeks, or months.

Patients who receive a combination of anesthetic and steroid medication may notice a slight increase in pain after the injection as the numbing medicine wears off and the cortisone starts to take effect. This increase in pain may last for a few days.

Repeat injections are typically reserved for patients who experience substantial improvement from the initial injection.

Rotator Cuff Injection Side Effects and Risks

The injections are generally well-tolerated, and the side effects are typically minor and transient. As with any injection procedure, there are risks of serious complications, but the incidence is rare.

Temporary side effects

It is common for local tenderness and swelling at the site of the injection. Sometimes, the injection site may feel numb or have slight bruising. In most cases, these side effects resolve within approximately 48 hours.

Potential risks

Serious risks and adverse events include:

• Allergic reaction to the medications or dye used in the injection
• Shoulder infection
• Depigmentation of the skin around the injection site (a whitening of the skin)
• Local fat atrophy around the injection site (thinning of the skin)
• Rupture of a tendon located in the path of the injection
• Nerve damage near the shoulder joint
• Bleeding at the injection site

In addition to the above, corticosteroid injections increase the risk of:

• High blood pressure
• High blood sugar
• Decreased immune function
• Decrease in bone mineral density
• Bone infection (osteonecrosis)
• Reproductive hormone imbalance
• Metabolic changes (eg, increased appetite, weight gain, and fluid retention)

These risks are typically associated with higher doses of corticosteroids, multiple injections, and for people with underlying medical conditions such as diabetes and heart problems.

When to See a Doctor

Prompt medical evaluation is warranted if one or more of the following symptoms occur after the injection treatment:

• Increased pain or swelling at the injection site that progressively worsens
• Fever, chills, and/or night sweats
• Uncontrolled or excessive bleeding at the injection site
• Persistent numbness or weakness in the neck, shoulder, arm, or upper back
• Headaches
• Swelling in the arms

Before considering a rotator cuff injection, patients are advised to discuss the risks, benefits, and alternative treatments with their doctor.