Osteocapsular Arthroplasty of the Elbow

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CHAPTER 9 Osteocapsular Arthroplasty of the Elbow

Arthroscopic osteocapsular arthroplasty is a procedure involving three-dimensional reshaping of the bones (i.e., removal of osteophytes), removal of any loose bodies, and capsulectomy to restore motion and function and to eliminate pain.¹

Arthroscopic release is effective for soft tissue contractures of the elbow.²^–⁵ When arthritic changes are present, bone work is also necessary.¹^,⁶^–¹²

ANATOMY

Osteophytes build up in typical locations along the margins of the joint and in the fossae. Although the patient may have osteophytes on the posteromedial olecranon, osteophytes alone do not always cause impingement pain. The relationship between bony osteophytes and impingement pain poses an apparent dilemma. It is not unusual to see osteophytes that impinge at the limit of motion in patients who have no pain. The question is why some osteophytes are painful and others are not. Based on experience and unpublished research in progress, I think the usual cause for impingement pain in such circumstances is a fractured olecranon osteophyte that has typically progressed to nonunion by the time of referral to the orthopedic surgeon.¹³ Nonunion fractures are best visualized (Fig. 9-1) on sagittal and coronal computed tomography (CT) reconstructions. The loose fragment is easily missed during arthroscopy because it is very small or covered with cartilage and not obviously loose. In some patients, the loose fragment is removed during osteophyte excision without ever being recognized. Other causes for the pain include loose bodies or buildup of inflamed soft tissue posteriorly.

FIGURE 9-1 Impingement pain in hypertrophic osteoarthritis usually is caused by a painful nonunion of a fractured osteophyte, most commonly on the tip of the olecranon (arrow).

PATIENT EVALUATION

History and Physical Examination

The patient reports posterior pain at the end point of extension. An associated contracture of some degree is almost invariably present.

I have found that the diagnosis of posterior impingement due to fractured nonunited osteophytes can be confirmed with confidence on physical examination using the extension impingement test and the arm bar test.¹³ The extension impingement test is performed by starting with elbow near full extension and then quickly (but gently to prevent injury) snapping it into terminal extension. This maneuver reproduces the posterior or posteromedial pain experienced during provocative activities such as throwing. A simultaneous valgus load normally enhances the pain if the pathology is primarily posteromedial.

Diagnostic Imaging

CT with three-dimensional surface rendering provides excellent imaging of the bony pathology (Fig. 9-2A). The individual bones can be isolated from each other and spun around in three dimensions, demonstrating the location and structure of each osteophyte and loose body. Two-dimensional sagittal and coronal reconstructions are also necessary, because they reveal the fine details not available in the three-dimensional images (see Fig. 9-2B), including nonunited fractures, the original floors of the fossae, and small loose bodies embedded in the cartilage surfaces. Axial two-dimensional reconstructions complete the imaging protocol.

FIGURE 9-2 Three-dimensional surface rendering (A) and two-dimensional sagittal (B) computed tomographic reconstructions of the posterior compartment show osteophytes on the olecranon and in the olecranon fossa. The circles in A and B represent the arthroscopic fields of view in C and D, respectively. C, Step 1 is to get in and establish a view. The arthroscopic view is indicated by the circles, revealing the tip of the olecranon (Olec), which is just barely detectable within the surrounding scar tissue. D, Step 2 is to create a space in which to work by removing scar tissue, stripping the scar tissue and capsule off the bone, and inserting a retractor to elevate the soft tissues. A much larger view is then possible in which the olecranon (Olec) can be seen impinging on the marginal osteophyte on the trochlea (Troch). Above that area is scar tissue covering the floor of the olecranon fossa (Fossa). (Courtesy of Shawn W. O’Driscoll, PhD, MD, Mayo Clinic, Rochester, MN.)

TREATMENT

Indications and Contraindications

Arthroscopic osteocapsular arthroplasty is ideally indicated for symptomatic primary hypertrophic osteoarthritis of the elbow (with contracture and pain at the end range of motion) and for osteoarthritis resulting from osteochondritis dissecans. Relative indications include arthritis and contracture due to trauma or burned-out rheumatoid arthritis.

The main contraindication is questionable or inadequate expertise of the operating surgeon. The anterior capsulectomy portion of an arthroscopic osteocapsular arthroplasty may be relatively contraindicated in a patient with prior submuscular transposition of the ulnar nerve. Lying on the anterior capsule, to which it may be scarred, the nerve is theoretically at increased at risk for injury during anterior capsulectomy.

Relative contraindications include post-traumatic arthritis with severe joint surface irregularities and painful crepitus or non-hypertrophic osteoarthritis in the patients older than approximately 65 years.

Conservative Management

Nonsurgical treatment of hypertrophic arthritis with contracture is limited to symptomatic relief of pain by rest, activity modification, and nonsteroidal anti-inflammatory medications. Neither physical therapy nor splints have proved effective for established contractures.

Alternative Surgical Treatments

Alternatives to arthroscopic osteocapsular arthroplasty include arthroscopic or open Outerbridge-Kashiwagi, open column, and open Tsuge procedures.⁶^,⁸^–¹² In my experience, drilling a hole through the olecranon fossa does not adequately decompresses the coronoid fossa or the olecranon fossa, and it fails to address osteophytes in the radial fossa. It also eliminates the bony landmarks used to determine just how much bone should be removed from the fossa. The open column procedure does not permit as accurate and complete removal of osteophytes or contracted capsule (e.g., medial gutter) as the arthroscopic procedure. The Tsuge procedure has a high morbidity rate with no apparent advantages over arthroscopic osteocapsular arthroplasty.

Arthroscopic Technique

Patient positioning is critical for this procedure. With the patient in the lateral (preferred) or prone positions, it is necessary to have the shoulder forward flexed at least 90 degrees and abducted slightly (i.e., elbow higher than the shoulder). Failure to do so will result in the shaver handle hitting the chest of the patient and preventing access to the coronoid fossa. I do not recommend using the supine position for this procedure. A tourniquet is used.

Arthroscopic osteocapsular arthroplasty is a complex procedure requiring a high level of experience in elbow arthroscopy for its safe and effective performance. I have learned by experience that it is best performed in a stepwise sequence, starting posteriorly and completing the work in the gutters before going anteriorly (Box 9-1).

Box 9-1 Sequence for Elbow Arthroplasty

1. Get in and establish a view

2. Create a space in which to work

3. Bone removal

4. Capsulectomy

I perform a limited open decompression of the ulnar nerve through a 1.5- to 2-cm skin incision at the beginning of the procedure. This step was added to lessen the risk of developing a delayed-onset ulnar neuropathy postoperatively.

Posterior Joint Compartment

Three standard portals are used routinely, and one or two accessory portals may be added. The three standard portals are the posterolateral, posterior, and direct midlateral (i.e., soft spot). Accessory portals (i.e., proximal posterolateral and proximal posterior) can be used for retraction.

Step 1: Get In and Establish a View.

The first step is to get in and establish a view. Place the scope in the posterolateral portal and the shaver in the posterior portal. Confirm by visualizing identifiable articular structures that you are inside the joint and that you have the correct anatomic orientation (see Fig. 9-2C). Touch the tips of the shaver and scope together by triangulation, and visualize the shaver blade. By using surface anatomic landmarks, it should be possible to verify the shaver is within the olecranon fossa. This can be confirmed by tactile feedback as the shaver is moved up and down the sides of the fossa and around its rim.

Step 2: Create a Space in Which to Work.

Creating a space in which to work is the most important step in osteocapsular arthroplasty. If a surgeon can predictably create a space in which to work, he or she has most of the skills necessary to do the rest of the operation. More important, this makes the surgery safer and easier to perform.

Creating a space in which to work involves synovectomy and removal of debris, scar tissue, and loose bodies so that the surgeon can see clearly (see Fig. 9-2D). The surgeon strips the capsule off the humerus proximally and removes remaining loose bodies. Adding a retractor through the proximal posterolateral or proximal posterior portal increases the space, just as retraction does with open surgery. Slight elbow extension helps.

A radiofrequency device can be used to remove scar and adhesions from the olecranon and fossa so that they do not wrap up in the burr used to trim the bone. However, the surgeon must not to allow the irrigation fluid to heat up and cause thermal necrosis of cartilage.

Step 3: Bone Removal.

In re-creating the coronoid and radial fossae, the key is to find the floor of the fossa, which is usually at least partially preserved under the osteophytes (Fig. 9-6). Removing the periosteal soft tissue layer under the osteophytes exposes smooth cortical bone, which is readily distinguished from the overlying trabecular bone in the osteophytes. Bone debris is removed using the shaver, because it will not wash off the surface of exposed muscle with irrigation alone.

FIGURE 9-6 Step 3 is bony work in the anterior elbow compartment. A, Osteophytes anteriorly encroach on the radial fossa (small arrows) and the coronoid fossa (large arrows), and they must be removed by recontouring the distal humerus. Osteophytes typically extend off the tip of the coronoid, as seen in Figures 9-2B and 9-3B, and they must be removed. By subtracting the radius and ulna, the osteophyte at the posterior margin of the capitellum can be seen (arrows). B, A burr in the coronoid fossa (Fossa) is used to remove the osteophyte (arrows). The coronoid (C) and the top of the trochlea (T) are seen at the bottom of the image. C, The coronoid fossa (Fossa) is restored. D, With hyperflexion, the osteophytes can be removed from the coronoid (C) flush with the top of the trochlea (T).

Step 4: Capsulectomy.

Anterior capsulectomy is performed by first releasing the capsule along the supracondylar ridges if this was not done during the stage of creating a space in which to work. The capsule is cut from medial to lateral aspects with a wide duckbill (i.e., duckling or punch biopsy) (Fig. 9-7). Release proceeds laterally to the lateral edge of the brachialis, indicated by a strip of fatty tissue surrounding the radial nerve (see Fig. 9-7D). The capsule is excised proximally on the medial side and centrally with the shaver disconnected from suction (see Fig. 9-7E and F). The remaining lateral capsule is divided with a fine, pointed scissors or other suitable instrument, and the proximal portion is excised (see Fig. 9-7G and H). I prefer to make the capsulotomy distally, where the interval between brachioradialis and extensor carpi radialis longus is readily identifiable, and I then excise the whole capsule. Some surgeons wisely recommend cutting the capsule more proximally, where the radial nerve is farther away. In either case, a small triangle of capsule may be left intact over the interval between the brachioradialis and extensor carpi radialis longus to protect the radial nerve. The capsular release must go right down to the collateral ligaments on each side for complete release.