Advanced Techniques

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CHAPTER 41 Advanced Techniques

PART A Arthroscopic Management of Lateral Epicondylitis

INTRODUCTION

Lateral epicondylitis, or tennis elbow, is the most common affliction of the elbow.

The origin of the extensor carpi radialis brevis (ECRB) has been implicated as the source of pathology in this condition.2,5,710,1316,18 Reported histopathologic findings in the affected tendon origin include vascular proliferation and hyaline degeneration, which are consistent with a chronic, degenerative process.10,14,18,20 Most commonly, surgical treatment is directed at excision of this pathologic tissue through an open approach or more recently arthroscopic methods.1,3,5,6,11,15,17,19,21,22

This chapter covers the anatomy of the extensor tendon origins at the humeral epicondyle based on anatomic dissections.4 The location of the ECRB tendon origin is defined relative to intra-articular landmarks. Using these data, a technique for arthroscopic lateral epicondylitis surgery is presented with early clinical results.

ANATOMY

The extensor carpi radialis longus (ECRL) and the ECRB have a unique relationship at the level of the elbow. The ECRL overlies the proximal portion of the ECRB such that the ECRL must be elevated anteriorly in order to visualize the superficial surface of the ECRB. A thin film of areolar connective tissue separates these two structures.

The origin of the ECRL is entirely muscular along the lateral supracondylar ridge of the humerus (Fig. 41-1). The muscle origin has a triangular configuration, with the apex pointing proximally. In contrast, the origin of the ECRB is entirely tendinous. Although it blends with the origin of the extensor digitorum communis (EDC), when dissected from a distal to proximal direction and using the tendon undersurface, it can be separated from the EDC back to the humerus (Fig. 41-2). The anatomic origin of the ECRB is located just beneath the distal most tip of the lateral supracondylar ridge (Fig. 41-3). The footprint is diamond shaped, measuring approximately 13 by 7 mm (Fig. 41-4). At the level of the radiocapitellar joint, the ECRB is intimate with the underlying anterior capsule of the elbow joint, but it is easily separable at this level.4

In an effort to develop a strategy for arthroscopic identification and release of the tendon origins, we performed a cadaveric study. The ECRB was identified at the level of the radiocapitellar joint by first separating the ECRL anteriorly from the extensor aponeurosis posteriorly (Fig. 41-5). The EDC origin was then dissected from anterior to posterior to expose the underlying ECRB tendon. The anterior and posterior borders of the ECRB were marked with intra-articular 18-gauge needles, and the ECRL/EDC interval and the skin were repaired (Fig. 41-5).

The specimens were then mounted, and elbow arthroscopy was performed. Based on pilot studies, a modified lateral portal was established from an inside-out technique. This portal was made several millimeters proximal and anterior to the top of the humeral capitellum. Using a monopolar thermal device (Arthrocare, Austin, TX), the tissue between the two needles was released from the humerus, taking care to use the previously determined intra-articular landmarks for the ECRB origin. The joint capsule was first ablated to expose the undersurface of the ECRB tendon. Above the anterior needle, the muscular origin of the ECRL was identified. The ECRB tendon was then released from its humeral origin and allowed to retract distally. Care was taken to release all the tissue located between the two needles and dissect down to the midline of the radiocapitellar joint as visualized arthroscopically.

The specimens were then removed from the mounting device and individually dissected. The ECRL/EDC interval was opened, and the origin of the ECRB was evaluated to document complete release. The elbow capsule was identified beneath this plane at the joint level. The origin of the lateral collateral ligament was then exposed by reflecting the remaining extensor tendon origin posteriorly. In addition, the posterior interosseous nerve (PIN) was dissected out to document that it was not compromised by the arthroscopic release procedure.

Dissection of the specimens revealed an intact extensor aponeurosis and a complete release of the underlying ECRB in all cases (Fig. 41-6). The capsule was identified as a separate layer beneath the ECRB release. The collateral ligament origin was not violated, and the PIN was well distal to the release and not compromised in any case (see Fig. 41-6). Using these data, an arthroscopic technique was designed for lateral epicondylar release.4

TECHNIQUE

The patient is positioned prone, with all bony prominences well padded. We favor regional anesthesia. Bony landmarks are drawn out including the path of the ulnar nerve.

Once the tourniquet is inflated, the elbow is insufflated with an 18-gauge needle introduced through the soft spot of the elbow (midlateral portal).

Next, a standard anteromedial portal is established (Fig. 41-7). This is started several centimeters proximal and anterior to the medial epicondyle and well anterior to the palpable intermuscular septum. Care is taken to slide along the anterior humerus, and the joint is entered with a blunt introducer or a switching stick. This medial portal allows one to view the lateral joint including the radial head, capitellum, and the lateral capsule. It is often helpful at this point to open the inflow to allow distension of the capsule. If visualization is a problem, a retractor can be introduced through a proximal anterolateral portal 2 to 3 cm proximal and just anterior to the lateral supracondylar ridge. A simple freer elevator is useful for this purpose. By tensioning the capsule anteriorly, improved visualization of the lateral capsule and soft tissues can be achieved.

A modified anterolateral portal is established using an inside-out technique. This is started 2 to 3 cm above and anterior to the lateral epicondyle (see Fig. 41-7

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