CHAPTER 12 Arthroscopic and Open Radial Ulnohumeral Ligament Reconstruction for Posterolateral Rotatory Instability of the Elbow

Felix H. Savoie, III, Larry D. Field, Daniel J. Gurley

Dysfunction of the lateral ligamentous complex of the elbow may produce considerable dysfunction in the activities of daily living.¹ Unlike the medial ulnar collateral ligament, whose injury results in disability during athletic activities, the radial ulnohumeral ligament (RUHL) complex is involved in even the simplest activities of the upper extremity. There has been a growing interest in the diagnosis and treatment of posterolateral rotatory instability (PLRI) of the elbow since the original description by O’Driscoll and colleagues in 1991.¹ Because the RUHL complex stabilizes the elbow during supination and extension activities, even mild injury to this area can cause difficulty in lifting and twisting activities, such as turning a key or opening a door.

ANATOMY

The RUHL complex as described by O’Driscoll and coworkers ¹ is formed by three separate components that may have a variable expression. The radial collateral ligament is adjacent to the capsule and courses from the lateral epicondyle to the annular ligament and then down to the ulna. The RUHL begins at a variable point on the posterolateral aspect of the lateral epicondyle and courses distally to the crest of the ulna while sending fibers to the annular ligament and blending with the lateral collateral ligament (Fig. 12-1). The annular ligament originates and inserts on the ulna while following a course around the radial neck.

FIGURE 12-1 The lateral ligament complex of the elbow.

Anatomic studies have attempted to define the involved tissue. Dunning and colleagues ² stated that the RUHL and the radial collateral ligament must be sectioned to achieve PLRI. They also found that they could not visually differentiate the two ligaments at their humeral origin. They could differentiate the RUHL from the radial collateral ligament only by identifying the distal extent of the RUHL at the supinator crest of the ulna.² Seki and associates³ were able to show that sectioning just the anterior band of the lateral collateral complex induced instability. This suggests that an intact RUHL cannot stabilize the elbow.³ These data demonstrate that the cause of PLRI is a spectrum of injury. Although originally described as sequelae of an elbow dislocation, these anatomic studies and a report by Kalainov and Cohen⁴ support our own experience that there is a continuum of injury between PLRI and frank elbow dislocation.¹^,⁵

Instability findings may coexist with the standard examination findings of lateral epicondylitis, radial tunnel, and posterolateral plica syndrome. Kalainov and Cohen ⁴ posit that PLRI may be a cause of these problems of the elbow. Twenty-five percent of patients in their study had previous surgery for chronic, recurrent lateral epicondylitis. We think that uncorrected posterolateral instability of the elbow may result in increased tension on the lateral musculature as it attempts to stabilize the elbow, thereby producing a secondary lateral epicondylitis. Other tertiary findings, such as an inflamed posterolateral plica and inflammation of the posterior interosseous nerve in or near the radial tunnel, may also occur with the instability. Physicians must look for the instability and fully evaluate the elbow of patients with all of these findings. The clinical examination recommended by O’Driscoll and colleagues¹ and by Regan and Lapner⁶ can assist in the determination of a coexisting instability as a base cause of these problems in the elbow.

The data suggest that the proximity of the extensor carpi radialis brevis to the RUHL and lateral collateral ligament complex during lateral epicondylitis procedures may contribute to the iatrogenic development of PLRI. In performing a standard extensor carpi radialis brevis tendon release and repair for recalcitrant lateral epicondylitis, the surgeon must remain on the anterior aspect of the lateral epicondyle to avoid damage to the RUHL complex and resultant instability.

Smith and colleagues ⁵ initially described the role of arthroscopy in treating PLRI, and there have been various anecdotal reports since then.⁷ In this chapter, we update and summarize the current information about the diagnosis and management of PLRI.

PATIENT EVALUATION

History and Physical Examination

A patient with PLRI often complains of a popping or catching of the elbow with activities. It is especially noticeable with certain routine daily activities, such as using the arms to help rise from a chair or in doing push-ups. Patients have histories of various injuries, with the spectrum ranging from an inconsequential fall to a frank elbow dislocation.

Instability is best demonstrated clinically with the pivot shift test of the elbow. As first described by O’Driscoll and colleagues,¹ this test with the patient in the supine position may elicit gross instability or pain and apprehension.¹ Two other clinical tests assess (1) pain when pushing up from an arm chair with the palms facing inward and (2) having the patient push up from a prone or wall-leaning position first with the forearms maximally pronated and then repeating the test with the forearms supinated, reproducing pain or instability, or both.⁶^,⁸

We prefer to examine the elbow with the patient in the prone position and use the table as a base to stabilize the humerus. The elbow in this position mimics the examination of a flexed knee, and the findings seem to be more easily reproduced between examiners. We begin by manually trying to rotate the forearm from the humerus in 90 degrees of flexion, palpating the radiocapitellar joint and using the wrist to supinate and rotate the forearm to reproduce the radial column subluxation away from the humerus. The radial head movement on the capitellum is more easily seen and felt in this position, and the elbow can be flexed and extended while maintaining the subluxation force.