The function of the elbow is to provide a stable link between the hand and the shoulder, allowing the hand to be positioned in space for completion of tasks integral to activities of daily living (1, 2, 3, 4). When this joint is disrupted by fracture or dislocation, prompt management can restore anatomy and preserve the functional integrity of the elbow (5,6). However, there are occasions when the initial injury is not diagnosed, is misdiagnosed, or is recalcitrant to treatment and persistent or recurrent chronic instability of the elbow ensues.

Chronic instability of the elbow is a spectrum of pathology that ranges from persistent or recurrent subtle dynamic ulnohumeral subluxation to chronic, fixed dislocation. It is uncommon to have a patient present with a chronic, fixed dislocation that has been undiagnosed or neglected. However, underdeveloped regions of the world without the luxuries afforded by industrialized health care systems have a higher incidence of chronic, fixed elbow dislocations. In some cultures initial management of these injuries may be provided by “witchdoctors” (8) or “bonesetters” (9) yielding inconsistent results. Much of the literature pertaining to the ultimate treatment of neglected elbow dislocations is provided by the experiences of clinicians from nonindustrialized health care systems (8,10, 11, 12, 13, 14, 15, 16).

Under advanced, industrialized health care systems, chronic elbow dislocations or fracture-dislocations can occur in patients who are noncompliant or fail to seek treatment, who are multiply injured where the dislocation
is either not recognized or unable to be addressed as a result of the prioritization of more severe injuries, or who have associated severe bony and soft-tissue deficiencies that are recalcitrant to primary treatment efforts (17,18). Most commonly prompt diagnosis and treatment occur; however, because of the complexity of the injury, concentric reduction of the ulnohumeral joint is not maintained.

Regardless of the presenting circumstances, a chronic elbow dislocation presents the clinician with a unique challenge that requires a true comprehension and understanding of the potential complex and extensive reconstructive options (17). Treatment options include open reduction and repair or reconstruction of all involved bony and ligamentous structures (8,11,13,15,16,19,20) with or without interposition arthroplasty (11), resection arthroplasty (12), ulnohumeral arthrodesis (21,22), and total elbow arthroplasty (TEA) (16,18,23, 24, 25, 26, 27).

Circumstances that may justify TEA include the presence of articular cartilage deficiency, severe periarticular bone or muscle loss, disuse or age-related osteopenia precluding open reduction and internal fixation (ORIF) or stable anchoring of ligament reconstructions, and patient-specific factors such as advanced patient age and/or an inability of the patient to participate in the postoperative regimen of a complex reconstructive effort (27,28).

This chapter reviews the essential issues to consider in the evaluation and treatment of a patient with a chronic elbow dislocation, including complete dislocation and “perched” partial dislocation. The unique pathophysiology, surgical anatomy, and treatment options will be reviewed as well as the evolving role that TEA plays in the management of this complex problem.

The chronic elbow dislocation has distinct pathologic anatomy, which must be identified and addressed to maximize treatment. Although the initial injury is one of instability, the surrounding soft tissues and bone quickly heal around the dislocated elbow in a nonanatomic and asymmetric fashion.

Patients with a chronic elbow dislocation present with obvious deformity, variable pain, and range of motion varying from complete ankylosis to a functional arc of motion. Patients with a chronic “perched” partial dislocation do not present with remarkable deformity but present with variable pain and range of motion.

A limited range of motion leads to subsequent disuse osteopenia and articular cartilage malnutrition (16). In addition, the articular cartilage is adversely affected by intraarticular scarring and delamination that may affect its quality and longevity.

The periarticular tendons and muscles that cross the elbow joint are not only at a mechanical disadvantage (8) as a result of the shortened extremity of a dislocated elbow, but they also quickly develop contractures and fibrosis as a result of the bleeding and subsequent healing response from the initial injury. This is especially true of the strong flexors (biceps, brachialis) and extensors (triceps) of the elbow. The severity of muscle and tendon contractures in this setting is time dependent, and the ideal surgical management of these contractures with either tendon mobilization(s) or lengthening(s) has been somewhat controversial (8,29). Although uncommon, avulsion of the insertion of the brachialis and triceps tendons associated with chronic elbow dislocation has been reported (30).

Fibrous thickening of capsular tissues coupled with periarticular myositis ossificans in the triceps and brachialis muscles or heterotopic ossification may also contribute to severe limitations of elbow motion. In addition, the ulnar nerve is often remarkably scarred and tight in the ulnar groove from bleeding of the initial injury as well as prolonged extension of the ulnohumeral articulation (8,13,16).

The empty olecranon and coronoid fossae are quickly filled with fibrous tissue, which may be difficult to distinguish from nascent articular cartilage (13). Synovial membrane destruction occurs with replacement by extensive fibro-fatty tissue leading to subchondral bone loss and delamination of intact articular cartilage (16). Although subacute cases may have surprisingly normal appearing cartilage (15), distinguishing scar from intact cartilage may be difficult (13).

Direct articular damage and subchondral bone loss of the trochlea is typically more severe in patients with chronic “perched” (partial) dislocation compared to fixed dislocation resulting from the erosion of the trochlea by the coronoid.

This combination of asymmetrically contracted soft tissues, intraarticular scarring with interposed fibrous tissue, disuse osteopenia, variable subchondral bone loss, and ulnar nerve scarring makes closed management of these injuries ill advised and potentially dangerous. Surgical intervention is warranted often as early as 2 to 3 weeks after the initial injury if iatrogenic fracture or neurologic injury is to be avoided (13).

Classically, ulnohumeral dislocation is sustained by a fall on an outstretched hand or any other mechanism whereby the soft tissues and/or bone are disrupted in a circular fashion pivoting around an intact anterior band of the medial collateral ligament (5). Simple elbow dislocations, defined as those without concomitant fractures, rarely require surgical intervention if managed appropriately in the acute setting (31). Closed reduction is performed with the subsequent stable range of motion arc noted. Protected motion is allowed within this arc for several weeks, and then progressive motion is allowed over the ensuing weeks to months (5). A slight flexion contracture (less than 15 degrees) is a fairly common long-term sequelae after successful
closed management of the simple elbow dislocation; however, more severe stiffness, persistent instability, or progressive arthrosis are rare (31).

Complex dislocations are defined as those associated with fracture(s) versus simple dislocations, which are limited to a soft-tissue capsuloligamentous injury. The incidence of associated fractures with elbow dislocations has ranged in the literature from 0% to 50% (8,11,13,15,29).

Elbows with chronic dislocation (partial or complete) are often complex dislocations with varying severity of bony involvement (5,6). The Mayo Classification of Elbow Instability (18) uses the three variables of time, extent, and direction of instability to appropriate the clinical scenarios of presentation (Table 27-1). It is the chronic unreduced subluxations and dislocations that are the subject of this chapter.

The precise timing of “acute,” “subacute,” and “chronic” in the Mayo Classification has not been strictly defined. Based on the relatively rapid development of the aforementioned pathologic anatomy around a dislocated elbow, treatment of an elbow dislocation with successful expectations should be initiated immediately and certainly no later than a few weeks after the injury, as outlined previously. Thus, although no literature specifically addresses this issue directly, it is intuitive that reduction of a dislocated elbow after approximately 4 to 6 months would have a high prevalence of posttraumatic articular degeneration (32,33). Thus, an algorithm for the treatment of elbow dislocations based on the timing of clinical presentation is presented in Table 27-2. Of course, patient-specific issues such as age, gender, hand dominance, activity level, comorbidities, expectations, and goals should be strongly considered and incorporated within this algorithm to choose the best treatment alternative.