Acute Elbow Dislocation
CDR Glen Ross, MD
Department Editor: William O. Roberts, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 27 - NO. 2 - FEBRUARY 1999
After the shoulder, the elbow is the second most frequently dislocated major joint (1). Because an acutely dislocated elbow has a dramatic appearance and the pain can be severe, the attending physician or trainer often feels pressure to "do something."
Elbow dislocations are usually the result of a fall on an outstretched hand with the elbow extended. Most are simple dislocations that involve no significant fractures. Complex dislocations are less common and involve major fractures that require surgical repair.
Posterior dislocations, in which the coronoid process disengages from the trochlea and moves posteriorly (figure 1), account for more than 90% of dislocations (2). Whether the elbow dislocates posteromedially or posterolaterally, the injury and treatment are the same (2).
Injured structures include the anterior and posterior bands of the medial collateral ligament and the lateral collateral ligament. The brachialis muscle, flexor-pronator muscle group, and articular cartilage may be injured as well.
The on-field assessment of the dislocated elbow is critical, because it can affect final outcome. The patient usually has swelling and obvious deformity. If possible, first ascertain the mechanism of injury. Next, evaluate the patient to rule out other injuries, especially in the ipsilateral upper extremity. Palpate for possible shoulder or wrist fracture or injury to the distal radioulnar joint. Then, gently palpate the elbow for crepitus to detect obvious fractures.
Next, do a complete neurovascular exam. Note pulses and check capillary refill. In most cases, vascular impairment will be reversed with reduction of the joint. Though anatomic injury to the brachial artery is rare, it does occur (3); it requires arteriography and referral. Neurologic injury is also uncommon. The ulnar nerve is most commonly injured, usually in a stretch neurapraxia.
At this point, it is necessary to decide whether to reduce the elbow or to splint the joint and send the patient to the emergency department. This decision should be based on the physician's familiarity with reduction and whether radiographs and intravenous sedation are needed before reduction.
Advantages of immediate reduction include pain relief and restoration of normal neurovascular status. Immediate reduction is often quite easy because spasm and muscle contracture have not set in and swelling is minimal. But if the elbow does not reduce easily, the patient should be taken to a medical facility.
Children who have elbow injuries should be evaluated with particular care and should usually be splinted and referred. Although elbow dislocations occur in children, fractures are more common. Radiographs should always be obtained, but they can be difficult to interpret because of multiple growth plates. Reduction should usually be performed under general anesthesia.
If the injury is a simple posterior elbow dislocation, and the clinician feels comfortable trying a reduction, the following should be done quickly:
A solid reduction often indicates a stable joint. Assess stability by moving the elbow gently through a range of motion, watching especially for instability as the elbow is extended. Splint the elbow in 90° of flexion and do a neurovascular exam.
We do not routinely hospitalize patients for observation following reduction of simple dislocations. However, radiographs should always be obtained after reduction and assessed for joint congruity, fractures, and alignment; the patient's radial head should line up with the capitellum in all views. Patients should be instructed on neurovascular status, especially on pain as a warning sign.
The leading complication of elbow dislocation is stiffness. Late instability is not usually a problem, but posterolateral rotary instability, due to injury of the lateral ligaments, has recently been described (4).
Rehabilitation protocol is controversial. Standard rehab includes splinting the elbow in 90° of flexion for 5 to 10 days followed by modalities and active range-of-motion exercises. At my institution, we try to minimize stiffness by reexamining patients the next day and starting aggressive rehab with supervised active range of motion (5). Such follow-up is critical to ensure good motion and function.
A simple dislocation that is treated properly has a good prognosis; a return to preinjury function is the goal.
Dr Ross is an orthopedic surgeon and team physician at the US Naval Academy in Annapolis, Maryland. Dr Roberts is a family physician in White Bear Lake, Minnesota, and an editorial board member of The Physician and Sportsmedicine.