The elbow is an inherently stable joint, due to 1) the congruent and form-fitting nature of the bones, 2) the muscles that cross the joint and tighten it, and 3) the collateral ligaments along the lateral and medial side of the joint that hold the humerus to the forearm.

Falling onto an outstretched arm can result in tearing of the elbow's collateral ligaments. If the tear is severe enough, the elbow joint may subsequently dislocate

Despite the stability of the joint, injuries creating instability of the elbow can occur.  The elbow is the second most commonly dislocated joint in the human body (behind the shoulder).  Elbow dislocations usually occur as the result from a fall onto the hand, or from another person falling onto the outside of the elbow such as during contact sports (see image on right)

Aside from a sudden traumatic event like a dislocation, an elbow joint can also become unstable due to chronic overuse.  This can occur from various stresses on the elbow, but is occasionally seen in baseball pitchers that injure their medial collateral ligament and subsequent require “Tommy John surgery”.

Injuries to the soft tissues around the elbow can result in subsequent elbow problems such as weakness, instability, stiffness, or arthritis (see images below)

Medial collateral ligament: The collateral ligaments on the medial side (inside) of the elbow provide stability during activities such as throwing. The "anterior" bundle of the ligament (shown in red and blue) is the most critical portion for maintaining elbow stability

Lateral collateral ligament: The collateral ligaments on the lateral side (outside) of the elbow provide stability during lifting and rotation. The posterior portion shown in green, known as the "lateral ulnar collateral ligament", is the most important structure for stability on the lateral side of the elbow. Injury to this structure can result a phenomenon known as posterolateral rotatory instability (PLRI). PLRI can result in symptoms of instability or frequent dislocations of the elbow joint

Dr. Schreiber has published numerous articles on elbow instability.  Click on the links to read more about how he used both videos and MRI to learn more about the causes of elbow dislocations.

Other injuries to the collateral ligaments of the elbow may require surgery.  Dr. Schreiber has published research on treating unstable elbows with repair of the injured ligaments.  For more information, click here.


Complete elbow dislocations are not subtle, and are usually reduced (relocated) either immediately at the time of injury or under sedation in an emergency room.  Mild elbow instability can be subtle, and the diagnosis is made from x-rays and from a physical examination.


Acute elbow dislocations can usually be successfully treated non-surgically.  During the healing process, specific rehabilitation protocols are used to minimize tension on the injured structures and optimize the chance that the ligaments heal in a normal (and not lengthened or lax) position.  An overhead motion protocol can allow early range of motion by placing the elbow in a protected position (see figure below). 

Overhead motion exercises. These exercises are performed under the direct supervision of a therapist. The patient is positioned supine (lying on back) with the shoulder flexed, adducted, and in a neutral to external rotation position. This position eliminates gravitational varus and distraction forces. In this position, A elbow flexion, B extension, C pronation, and D supination motion exercises are performed.

By performing range of motion exercises in a supine (lying down) position, the weight of the forearm helps to hold the elbow joint reduced, whereas performing early motion with the arm by your side results in gravity causing distraction across the joint.  It also transitions the triceps muscle from a joint distracting force to a joint stabilizing force.

The overhead motion protocol has been shown to produce excellent range of motion outcomes following elbow dislocations.  To read more about Dr. Schreiber’s research on the overhead motion protocol and outcomes following elbow injuries, click here

Elbow “fracture-dislocations” include both an elbow dislocation, and a broken bone within the joint. These injuries are often unstable, and if not treated appropriately, can result in decreased motion, arthritis, and repeat dislocations. A. An elbow fracture dislocation, showing a dislocated ulno-humeral joint and a radial head fracture. B. Despite an attempt at relocating the elbow joint, it remains unstable due to the fractured radial head. C. Fractures of the radial head involving >3 pieces are usually replaced with a metal implant, which is specifically sized to match the patient. D. In this patient, excellent range of motion was obtained and stability of the joint was restored.

Other injuries to the collateral ligaments of the elbow may require surgery.  Dr. Schreiber has published research on treating unstable elbows with repair of the injured ligaments.  For more information, click here

Dr. Schreiber is a board certified orthopedic surgeon specializing in hand, wrist, and elbow conditions. Dr. Schreiber practices at the Raleigh Orthopaedic Clinic in Raleigh, North Carolina.