Elbow joint stability is dependent on a highly congruent skeletal articulation and collateral ligaments. Dislocations of the elbow are relatively common, being the second most commonly dislocated major joint. Most simple elbow dislocations are managed with closed reduction, a brief period of immobilization, and early protected rehabilitation. Elbow dislocations associated with fractures of the radial head and the coronoid are complex injuries that are much more likely to require surgical intervention.

The elbow is stabilized by both the bony congruency of the joint and the periarticular soft-tissue structures. The soft-tissue structures on the medial side (Figure 19.1) are the medial collateral ligament (MCL) complex and the flexor pronator mass. The lateral (Figure 19.2) side soft tissues include the lateral collateral ligament complex (LCL) and the extensor and supinator muscular complex. The primary restraint to valgus instability is the radial capitellar joint, while the MCL is a secondary stabilizer that becomes the primary stabilizer if the radial head is removed. The bony congruency of the ulnar trochlear articulation is the primary restraint to varus stress, with the LCL being a secondary stabilizer.

Supination and axial loading of the forearm causes the ulna and radial head to rotate away from the distal humerus, with the radial head translating posterior to the capitellum and the lateral ulna rotating away from the lateral trochlea. The lateral ulnar collateral ligament (LUCL) is the primary stabilizer to prevent this instability pattern, known as posterolateral rotatory instability (PRLI).

Most elbow dislocations occur as a result of a fall onto an outstretched arm. The forearm is forcibly supinated and axially loaded. In addition, the valgus-carrying angle and slight degree of flexion convert the axial load into a valgus thrust. This mechanism results in injury of the stabilizing structures around the elbow. O’Driscoll described the stages of elbow instability as beginning with a failure of the LUCL, with progressive disruption of the anterior and posterior capsule. In severe cases, the medial ulnar collateral ligament (MUCL) is also injured. This unlocks the forearm from the humerus, and allows the radial head to dislocate behind the capitellum.

In cases of complex instability, the radial head is driven into the capitellum and the coronoid into the trochlea before the forearm is fully disengaged, resulting in various degrees of fracture of the radial head and coronoid in addition to the collateral ligament injuries. The terrible triad injury pattern consists of an elbow dislocation, radial head fracture, and coronoid fracture.

PRLI is a relatively rare late sequelae of traumatic elbow dislocation or subluxation. It occurs when the LCL complex fails to heal sufficiently to prevent the forearm from rotating away from the humerus, resulting in either recurrent frank dislocations or subluxations of the elbow. Varus posteromedial rotatory instability (VPRI) is caused by a varus load, which results in failure of the LCL under tension and fracture of the medial ulna joint line due to compression of the coronoid against the medial aspect of the trochlea.

Although there is no “one-size-fits-all” approach to rehabilitation after operative fixation of elbow instability injuries, there are general principles that can be applied and utilized in individual cases. The initial postoperative management focuses on preventing and decreasing swelling, managing pain, and protecting the repair. The primary rehabilitation goals after surgical treatment of elbow dislocation are restoring joint mobility while protecting the surgical repair, preserving elbow stability, and eventually restoring function. Increases in ROM should not be gained at the expense of joint stability. Restoring a functional arc of motion is essential to enabling the patient to return to normal activities. While normal elbow ROM has been measured as 0° to 140° of flexion and extension, and supination/pronation 80° to 85°, the functional ROM to complete most activities of daily living (ADLs) has been established as 30° to 130° (flexion/extension) and 50°/50° supination/pronation, although some common tasks may require higher degrees of flexion and forearm rotation. It is important to educate the patient early about the expected ROM losses, especially elbow extension. A loss of 15° of elbow extension is not an uncommon sequela of even simple elbow dislocations.

Patients are splinted in the operating room and placed in a sling. The splint rests the soft tissue to help reduce swelling and protect the repair. The splint is typically discontinued 7 to 10 days after surgery. The splint can be replaced with either a custom-molded orthoplast removable splint, or a prefabricated brace, which can be removed for hygiene and permit early ROM exercise while protecting the repair (Figure 19.4).

Gentle active and active assisted exercises are typically initiated within the first 7 to 10 days after surgery. Active range of motion (AROM) rather than passive range of motion (PROM) is advocated to take advantage of the compressive stabilizing forces of the muscles surrounding the elbow. The patient is encouraged to remove the orthosis and perform these exercises at frequent intervals throughout the day. As the bone and soft tissues begin to heal, the ROM can be progressed and light functional activities can be initiated. Strengthening is begun once the joint is declared stable by the physician. In general,
the elbow has enough healing to tolerate strengthening around 8 weeks after surgery. Comminuted coronoid or radial head fractures may need to be protected for a longer duration.

Dependent on the amount of soft-tissue trauma, there may be substantial swelling and edema in the first 14 days postoperatively. Capsular thickening and co-contracture of the brachialis muscle develops within days of the injury, leading to restricted movement of the elbow, especially with extension. Edema management can include elevation, retrograde massage, and the use of light compressive dressings and sleeves.

Pain also contributes to stiffness and muscle guarding. The therapist needs to distinguish between the normal level of pain associated with the injury and surgery versus pain from nerve irritation. Care must be taken to monitor the ulnar nerve on the medial aspect of the elbow for irritation/instability. Symptoms will include tenderness to palpation of the medial aspect of the elbow and paresthesias in the ring and small fingers. Uncontrolled neuritis and neuropathy with associated pain can lead to elbow contracture as well as reflex sympathetic dystrophy and chronic regional pain syndrome (CRPS). Prolonged ulnar compression can also lead to muscle atrophy or wasting of ulnar innervated muscles, including the hand interossei.

Pain management techniques, including medication, transcutaneous electrical nerve stimulation (TENS), biofeedback, and relaxation techniques may be employed to decrease pain and increase the ability to participate with the therapeutic exercises.

The patient is encouraged to use the affected arm for functional activities, within protected guidelines, throughout the rehabilitation process. For example, if in a splint, the patient may still be able to use the affected hand as a helper for ADLs. When a patient has a weight limit on lifting, it is still beneficial to use the elbow for unweighted ADLs. Since the function of the elbow is to position the hand for functional activities such as dressing, bathing, and eating, patients are usually highly motivated to progress toward these goals.