Shoulder Impingement Syndrome – Shoulder Tendonitis

Introduction

Shoulder impingement syndrome is a painful condition in the shoulder. It occurs when the tendons in the shoulder are irritated, inflamed or degenerated from repetitive overhead motions or structural abnormalities in the shoulder. Shoulder impingement syndrome is treated with activity modification, medication, and therapy. When non-surgical options fail, surgical treatment may be used to relieve symptoms and restore function.

Anatomy

Your shoulder is composed of three bones. The humerus is your upper arm bone. The clavicle is your collarbone. The scapula is the shoulder blade that moves on your back. A prominent edge of the scapula, the acromion, forms the top of the shoulder.
The head of the humerus is round. It rotates in a shallow basin on the scapula called the glenoid. A group of ligaments, called the joint capsule, hold the head of the humerus in position. Ligaments are strong tissues that connect bones and provide stability. In other words, the joint capsule is responsible for holding your upper arm in place at your shoulder.
Four muscles at the shoulder form the rotator cuff of tendon that connects to the head of the humerus. The muscles allow the arm to rotate and move upward to the front, back, and side. A gliding membrane, the bursa, lubricates the rotator cuff tendons and reduces friction around them when they move.
You use your rotator cuff muscles whenever you perform overhead motions, such as lifting your arms up to put on a shirt or reaching for an item on a shelf. These motions are used repeatedly during sports, such as serving in tennis, pitching in baseball, stroking in swimming, and passing in football. Overhead motions may also be used for job duties, such as for construction.

Causes

Impingement syndrome usually occurs as a result of muscle imbalance around the shoulder that place increase stress on the rotator cuff tendons. Secondary impingement syndrome results from the rubbing or pinching of the tendons and bursa during repetitive overhead movements. Shoulder impingement syndrome occurs when the space beneath the acromion is too small for the rotator cuff tendons. The space may be too narrow because of structural abnormalities in the shoulder bones, bone spurs, or thickened tissues.
As the tendons and bursa rub together during movement, it causes friction, pain, and limited motion. Degenerated tendons can become painful. Tendons may develop tendonitis, and the bursa may develop bursitis. Both are painful conditions. Continued inflammation can cause the rotator cuff tendons to tear or detach from the top of the humerus.

Symptoms

Shoulder impingement syndrome causes a generalized aching pain in the shoulder and upper arm. You may feel weakness and pain when you raise your arm for activities, such as combing your hair or putting on a shirt. Pain at night is typical and may interfere with sleep.

Diagnosis

Your doctor can diagnose shoulder impingement syndrome by reviewing your medical history and examining your shoulder. X-rays are ordered to check for bone spurs or acromion abnormalities. A magnetic resonance imaging (MRI) scan may be used to show more detailed pictures of your shoulder, particularly the rotator cuff, the muscles and joint capsule.

Treatment

Treatments for shoulder impingement syndrome include rest from the irritating activity and ice packs or medication for pain and inflammation.
Ultrasound Guided Cortisone injections are used, followed by Physical therapy to regain motion and strengthen weakened muscles, thereby decreasing pain.
Ultrasound Guided Platelet rich plasma injection or Stem Cells injection for regeneration is promising (not FDA approved) but supported by multiple Studies.