Tennis Elbow lateral epicondylitis
The extensor muscles of the forearm are the muscles that act to extend, or pull back, the wrist and fingers.  The tendons of forearm extensors come together to form the common extensor tendon.  This attaches to the humerus (upper arm bone) at a bony prominence called the lateral epicondyle.  Injury or overuse can cause chronic pain and inflammation at the attachment of the common extensor tendon and lateral epicondyle.  This is known as tennis elbow, or lateral epicondylitis.
Tennis elbow is typically an overuse injury.  Repetitive, strenuous extension of the wrist and hand can, over time, cause inflammation at the common extensor tendon and lateral epicondyle.  This is common among tennis players because of the backhand swing.  But it can happen with a variety of activities including carpentry or even typing.
Tennis elbow is diagnosed based on a history and a physical exam.  Patients with tennis elbow usually report gradually worsening pain on the outside of the elbow.  Pain is typically worse with wrist extension.  Pain may be exacerbated by an injury.
Physical exam findings include tenderness over the lateral epicondyle and pain with resisted extension of the wrist.
Tennis elbow cannot be identified on x-rays, but they are often obtained to look for other causes of elbow pain such as arthritis or fractures.
Tennis elbow is almost always treated without surgery.  Anti-inflammatory medications, elbow straps and braces, ice, rest, and activity modification are first-line treatments.  Other options include steroid injections and physical therapy.  Even with good treatment, tennis elbow may take several months to resolve.
Platelet-rich plasma (PRP) injections have been used to treat tennis elbow that does not respond to more conservative treatment.  A specific portion of the patient’s own blood is injected over the damaged tendon.  This promotes healing.  The elbow must be put at rest for a few weeks after the injection.
normal elbow MRI
normal elbow x-rays
humerus
If tennis elbow is diagnosed but is not improving after months of treatment, an MRI may be obtained to evaluate the common extensor tendon and to rule out other possible causes of elbow pain.
tennis elbow
Surgery may be considered if tennis elbow persists despite several months of non-surgical treatment.  Surgery for tennis elbow involves debriding damaged tendon tissue.  If necessary, the tendon may be repaired with sutures or anchors (small screws with sutures attached).
radius
common extensor tendon
lateral epicondyle
lateral epicondyle