Posterolateral Rotatory Instability of the Elbow

Abstract

Symptomatic posterolateral rotatory instability (PLRI) results from a lateral collateral ligament complex injury and presents with pain, clicking, and subluxation within the flexion and extension arcs of elbow motion. Often, symptoms and examination characteristics are subtle and can be easily misdiagnosed. Therefore, a thorough history and provocative physical examination maneuvers are important to correctly establish the diagnosis. Patients frequently have a history of elbow trauma such as an episode(s) of elbow dislocation, prior surgery, or previous cortisone injections. Radiographs and advanced imaging can aid in the diagnosis, and examination under anesthesia, manipulation with arthroscopic visualization, and/or stress radiographs can be confirmatory. Symptomatic cases of PLRI can be effectively treated with a repair or isometric ligament reconstruction.

Elbow Instability

“…Radiographic evaluation of PLRI should begin with radiographs of the elbow, which are frequently normal. Signs consistent with PLRI on radiographs of the elbow include bony avulsions, coronoid or radial head fractures, or widening of the ulnohumeral joint or posterior displacement of the radial head [ 20 ]. Stress radiographs or fl uoroscopy while performing the pivotshift test may reveal subluxation and posterolateral rotation of the radial head and ulnohumeral joint.…”

MR Imaging of the Elbow

“…8 Factors that may contribute to PRLI include a history of previous trauma, chronic resistant lateral epicondylitis, and prior lateral elbow surgery, with posttraumatic laxity, disruption, or avulsion of the LUCL considered the main contributing factor. 8,10 Since first described by O'Driscoll and colleagues in 1991, 11 the understanding of PLRI pathoanatomy has increased steadily over the last 2 decades. The typical mechanism of injury is falling onto an outstretched hand with the shoulder abducted, resulting in axial compression.…”

“…A staging system ( Table 5) described by O'Driscoll may influence the collection of a patient's history, clinical examination, and options for treatment. [8][9][10] Patients with PLRI may have pain and discomfort in the elbow as well as sensations of locking, clicking, snapping, or slipping, typically noted at 40 of flexion as the arm goes into extension within the arc of motion. In asymptomatic patients, nonoperative measures can include avoidance of instability-causing activities, elbow bracing to limit supination and valgus loading, application of a sugar tong cast, pain control, or physical therapy.…”

“…If symptoms or instability persist, operative intervention is indicated. 10 In clinical settings, clear imaging of the elbow is generally difficult. When the level of suspicion is high and radiograph results are normal, MR imaging should be performed.…”

“…3,8 The most significant complications are recurrence and arthrosis; others include infection, bony bridge fracture, cutaneous nerve injury, and arthrofibrosis that results in a flexion contracture. 10 …”