Kenneth J. Faber
Scott P. Steinmann
Inflammatory Arthritis
Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that affects synovial joints. The prevalence is approximately 1.0% of adults, and the disease is associated with significant morbidity and mortality. The treatment of RA has changed significantly over the past decade. In addition to new medications that have improved the treatment of inflammatory arthritis, advancements in elbow arthroscopy have resulted in the introduction of new surgical techniques.
Pathogenesis
The exact cause of RA remains unknown. One proposed mechanism involves the interaction between an unknown exogenous antigen and the host immune system that precipitates a response that recruits and activates monocytes and macrophages. The activated monocytes and macrophages release proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) into the joint. The cytokines mediate joint destruction by activating chondrocytes and fibroblasts that release metalloproteinases and collagenases capable of cartilage and bone destruction. A second proposed pathway for joint destruction is through deregulation of B lymphocytes that subsequently produce rheumatoid factor and autoantibodies and promote the formation of destructive immune complexes.
Diagnosis
History and Physical Examination
Clinical Features.
Joint destruction is acknowledged to occur early in the disease process, and ≤60% of patients will have radiographic evidence of erosions by 2 years. Intra-articular symptoms associated with RA can be clustered into three groups: (a) pain, (b) restricted motion, and (c) instability. Extra-articular symptoms secondary to joint synovitis include local nerve compression, tenosynovitis, and tendon rupture.
Pain as a consequence of persistent inflammation is a common feature of RA. A secondary fibrotic reaction can occur in response to the inflammation and results in decreased elbow flexion and extension. If the radiocapitellar articulation is affected, forearm rotation can be restricted. As the disease progresses, cartilage destruction, bone loss, and ligament incompetence can result in joint instability.
Radiographic Features.
The radiographic features of rheumatoid arthritis have been classified by Larsen1 and subsequently modified by Morrey2 (Table 62-1; Figs. 62-2, 62-3, 62-4, 62-5).
Treatment
Pharmacotherapy
Conventional pharmacotherapy for the treatment for RA includes nonsteroidal anti-inflammatory medications and disease-modifying antirheumatic drugs (DMARDs) such as methotrexate, prednisone, sulfasalazine, and gold. Combination therapy with these agents has been shown to decrease disease activity and reduce radiographic progression of bone erosions. In most patients, this form of treatment is adequate.
Newer therapies take advantage of the improved understanding of the alteration in the immune system that contributes to the development of RA.3 For example, leflunomide (Arava) inhibits the synthesis of pyrimidine by activated T lymphocytes, thereby hindering the
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T lymphocytes' ability to initiate an inflammatory response. Etanercept (Enbrel), infliximab (Remicade), and adalimumab (Humira) all exploit strategies to bind the inflammatory cytokine TNF-α. Anakinra (Kineret) is an IL-1 receptor antagonist that competes with IL-1 and blocks the production of metalloproteinases that have been shown to destroy cartilage and create bone erosions. Each of these medications has demonstrated efficacy according to the definition of improvement in rheumatoid arthritis guidelines described by the American College of Rheumatology.4
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TABLE 62-1 Classification |
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Surgical Indications/Contraindications
The indications for surgical intervention include the failure of an appropriately supervised course of pharmacotherapy, symptoms of sufficient severity to justify the risks of surgery, and satisfactory general health to permit the safe performance of a surgical procedure. Ensuring satisfactory general health may require the assistance of rheumatologists, anesthesiologists, and general internists. In general, synovectomy is considered in patients with stage I or II disease and in select cases of stage III disease in young individuals. More advanced disease, manifested by joint destruction and mechanical instability, is likely to benefit most from total elbow arthroplasty (Fig. 62-1).
Open Synovectomy.
The standard treatment of early rheumatoid arthritis involves radial head excision and synovectomy. This procedure is usually performed through
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a lateral exposure using the Kocher interval between anconeus and extensor carpi ulnaris. Radial head excision is performed to improve forearm rotation and to increase joint exposure, thereby facilitating synovectomy.
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Figure 62-1 Inflammatory arthritis disease progression. |
The outcomes from this procedure are satisfactory, with patients reporting diminished pain and improved range of motion. Ferlic et al.5reported that 77% of patients described symptom relief following synovectomy and radial head excision. A subgroup of patients treated with silicone radial head arthroplasty was indistinguishable from the patients treated with synovectomy and excision alone. The best results were observed in patients with early disease. In a survivorship analysis, Gendi et al.6 identified factors associated with a poor outcome following open elbow synovectomy including advanced disease, long duration of symptoms, a significant reduction in the elbow flexion/extension arc, and poor general health. Using severe pain or the need for revision surgery as the end point, 80% of patients had a satisfactory response during the first year following the intervention, but additional failures accumulated at a rate of 2.6% per year.
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Figure 62-2 A: Stage I rheumatoid arthritis. B: Stage I rheumatoid arthritis. |
Another survivorship analysis reported by Mäenpää et al.7 found that 77% of elbow synovectomies did not require additional surgery at a mean of 5 years following the primary synovectomy. Patients undergoing synovectomy for late-stage arthritis were most likely to be revised to an elbow arthroplasty. Elbow pain and patient satisfaction both improved following synovectomy, but range of motion was unchanged.
Selected reports describing the outcome of open synovectomy are summarized in Table 61-2. Outcomes are difficult to interpret because of methodologic shortcomings including a lack of comparator groups, the use of nonstandardized outcome measures, and deficient statistical measurements. The best indications for elbow synovectomy, based on the papers cited, include pain, early radiographic changes (I and II), and restricted elbow motion. Although early results are rewarding, the durability of the results remains questionable.
Arthroscopic Synovectomy.
Arthroscopic elbow synovectomy offers several advantages over open synovectomy. The improved joint visualization achieved with arthroscopy allows for a more thorough synovectomy without sacrificing
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the radial head. The radiocapitellar articulation normally transmits 40% of the forearm axial load across the elbow joint. Radial head excision may result in accelerated wear of the ulnohumeral joint as a consequence of altered joint reaction forces. Radial head excision can still be performed if required using standard arthroscopic techniques. The morbidity of synovectomy is reduced using portals that minimize muscle injury and protect ligamentous stabilizers of the joint.
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Figure 62-3 A: Stage II rheumatoid arthritis. B: Stage II rheumatoid arthritis. |
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Figure 62-4 A: Stage III rheumatoid arthritis. B: Stage III rheumatoid arthritis. |
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Figure 62-5 A: Stage IV rheumatoid arthritis. B: Stage IV rheumatoid arthritis. |
Despite its many advantages, arthroscopic synovectomy is a technically difficult procedure that requires advanced arthroscopy skills. Furthermore, an assistant is required for limb positioning and for intra-articular retraction of nerves and vessels to avoid neurovascular injury. At the present
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time, the superiority of arthroscopic synovectomy over open synovectomy has not been proven.
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TABLE 62-2 Outcomes Reported Following Elbow Synovectomy |
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Figure 62-6 Patient positioned for elbow arthroscopy. The elbow is placed high to avoid contact with the arthroscope or other instruments against the patient. |
Several principles promote the safe performance of an arthroscopic synovectomy. First, the surgeon must possess a thorough knowledge of the three-dimensional anatomic relationships among nerves, vessels, synovium, capsule, and articular structures. This allows for safe portal placement and efficient insertion and removal of surgical instruments. Second, arthroscopic irrigation fluid should not be considered as a means to maintain joint distention but rather as the medium to clear debris from the joint. Ideally, inflow pressure should be minimized to prevent harmful fluid extravasations that obscure surface anatomy landmarks and interfere with the use of arthroscopic instruments. Third, a surgical assistant providing intra-articular retraction helps to maintain joint visualization and to prevent iatrogenic nerve injury. Finally, the procedure must proceed in a sequential manner that minimizes the risk of complication. For example, synovectomy precedes any planned bone resection since the synovium will likely obscure the visualization of osseous structures within the joint. Similarly, bone resection precedes planned capsulectomy since satisfactory irrigation fluid management is difficult to maintain once the capsule has been removed. By strictly adhering to the above principles and by exercising patience during the procedure, arthroscopic synovectomy can be safely performed.
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Figure 62-7 View of patient positioned for elbow arthroscopy. |
Lee and Morrey9 reported the outcome of arthroscopic synovectomy in a series of 11 patients at 42 months following surgery and found that only 6 of the patients continued to report a satisfactory result. Four of the patients required revision surgery and were treated with total elbow arthroplasty. Their recommendation was to cautiously advise patients regarding arthroscopic synovectomy since the initial early satisfactory response did not seem durable.
More recently, Horiuchi et al.10 described the results of arthroscopic synovectomy in a series of 27 patients. Durable pain relief was observed at a mean follow-up of 97 months. The best results were obtained in patients with early disease whereas the outcome in patients with more advanced disease was unsatisfactory. Their conclusion was that arthroscopic synovectomy could reliably relieve pain in patients with stage I or stage II disease.
Interposition Arthroplasty.
Although interposition arthroplasty is a recognized treatment for posttraumatic arthritis, there are several reports of the outcome of interposition arthroplasty for the treatment of RA. A number of interposition materials have been used including autogenous fascia, dermis, and allograft tissue. Distraction with an articulated external fixator is recommended to protect the interposition material during the early postoperative period.
The rationale of interposition arthroplasty is to replace damaged articular surfaces with an interposition material that eventually undergoes transformation into a new fibrocartilage articular surface. This transformation requires biologic robustness that can promote healing and soft tissue integration into the humerus and ulna. In an immunosuppressed host with impaired tissue healing, it is unknown whether the interposed tissue actually undergoes the expected changes.
In general, the results of interposition arthroplasty have not been encouraging. Ljung et al.11 reported their outcomes following interposition arthroplasty and found that patients reported diminished pain, but that there were no significant improvements in joint motion. Of concern, they observed progressive bone loss in two thirds of humeri and in one third of ulnae. In some instances, the bone loss interfered with their ability to perform revision surgery. Total elbow arthroplasty was favored over interposition arthroplasty based on their comparison of outcomes following both procedures.
Osteoarthritis of the Elbow
Primary degenerative arthritis of the elbow joint is relatively uncommon.12,13,14 Primary osteoarthritis of the elbow tends to occur predominantly in manual laborers and those who rely on wheelchairs or crutches for ambulatory assistance.13,15,16,17 Three main pathologic processes are involved in osteoarthritis of the elbow. Reactive bone and cartilage formation give rise to osteophytes. Loss and fragmentation of cartilage can lead to loose body formation.
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These two processes cause impingement and contribute to the third process of joint contracture.17,18 Symptoms include pain at the end points of motion, loss of extension, and mechanical symptoms such as catching or locking.12,15 Other commonly associated conditions include cubital tunnel syndrome with paresthesias and weakness in the ulnar distribution and decreased grip strength.15,19
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Figure 62-8 A: Preoperative radiograph of a typical patient, a 47-year-old right hand–dominant man with right elbow osteoarthritis, demonstrates osteophyte formation and joint space narrowing. B: Postoperatively, the osteophytes and bony spurs have been removed. |
Historical treatments have included nonoperative measures such as anti-inflammatory medications and activity modifications.13 Total elbow arthroplasty, although it reliably provides pain relief and improved range of motion, may be associated with early aseptic loosening in young active patients and should rarely be done primarily in this group.20 Elbow arthrodesis is a potential procedure in this population; however, many patients find the restricted motion postoperatively undesirable.20 Multiple open debridement procedures have been used with good success.12,15,17,21,22,23,24 Arthroscopic debridement and resection of osteophytes and capsule is a technique that addresses the underlying pathologic processes and provides outcomes similar to open procedures, and is associated with minimal perioperative morbidity.13,25,26,27,28
In positioning the patient for elbow arthroscopy, the lateral decubitus position allows for excellent joint access (Figs. 62-6, 62-7). The arm is cradled in a padded arm holder that attaches to the side to the table. A nonsterile tourniquet is then placed high on the arm at the level of the arm holder. The arm should be secured to the arm holder. This is helpful during instrumentation since the arm remains stable, similar to how a knee holder maintains stability during knee arthroscopy. The elbow should be positioned slightly higher than the shoulder. This will allow for 360-degree exposure of the elbow joint, eliminating potential impingement of the arthroscope or shaver against the side of the body.
It is best to mark all potential portal sites before surgery when the elbow is not distended or edematous and palpation of bony landmarks is more precise. Surface landmarks that should be marked with a pen in all patients include the ulnar nerve, the lateral epicondyle, medial epicondyle, the radial head, capitellum, and olecranon.
Distending the elbow with fluid prior to making the starting portal is an important step in contrast to techniques in the shoulder or the knee. The elbow can be injected with 20 to 30 mL of fluid at the location of the anterolateral portal just anterior to the radiocapitellar articulation. With the elbow joint distended, the major neurovascular structures are positioned farther from the starting portal site and entry into the joint is easier.
The choice of starting portal depends on surgeon preference. No starting portal has been shown to be better than another, and ultimately the experience of the surgeon and his or her knowledge of anatomy is the best guide to elbow arthroscopy. Superficial cutaneous sensory nerves are common about the elbow and can be injured during portal placement.
Once the arthroscope has been placed into the joint, visualization can be maintained by pressure distention of the capsule or by mechanical retraction. Retractors for the elbow are simple lever retractors such as a Howarth or a large blunt Steinmann pin. Retractors are placed into the elbow joint via an accessory portal, which is typically 2 to 3 cm proximal to the arthroscopic viewing portal. By holding the capsule and overlying soft tissue away from the bone with retractors, adequate visualization can be achieved with a high-flow, low-pressure system.
Kashiwagi described a procedure, now known as the Outerbridge-Kashiwagi procedure, in which a triceps splitting approach is used to access and débride osteophytes and loose bodies from the posterior aspect of the elbow joint. Fenestration of the olecranon fossa allowed access to the anterior aspect of the joint, and loose bodies and osteophyte removal was facilitated by use of an osteotome and irrigation.22 Others have subsequently described arthroscopic modifications of this procedure and have demonstrated satisfactory clinical outcomes following use for treatment of osteoarthritis.13,16,28,29 Cohen et al.28
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compared outcomes following arthroscopic debridement versus open debridement of the elbow for osteoarthritis using the Outerbridge-Kashiwagi procedure and the arthroscopic modification. Both groups demonstrated improved range of elbow flexion, decrease in pain, and a high level of patient satisfaction. Increases in elbow extension, although improved in both groups, were more modest. However, neither procedure included capsular release. Comparison between the open and arthroscopic procedures demonstrated that the open procedure might be more effective in improving flexion whereas the arthroscopic procedure seemed to provide more pain relief. No differences between overall effectiveness of the two procedures were noted.28 Heterotopic ossification prophylaxis should be considered in these patients, as this complication has been demonstrated to occur in the postoperative period following elbow procedures.30,31
Using an arthroscopic approach, all areas in the anterior and posterior aspects of the elbow joint can be visualized and pathology addressed (Fig. 62-8). To obtain a similar view and access using open techniques would require large surgical exposures and incisions with presumably attendant increased morbidity. Despite the many advantages of arthroscopy in addressing elbow pathology, it remains a technically demanding procedure that requires a high level of arthroscopic experience and training to perform safely.
Performing a complete capsular resection provides better range of motion postoperatively and leaves less opportunity for recurrent scar or contracture formation. By removing the capsule, the pliability of the joint and overlying soft tissues is improved, leading to better possible range of motion. The surgeon should exercise caution in performing this procedure owing to the potential for neurovascular injury. In particular, care should be exercised when working about the radial head. The fat pad near the posterior interosseous nerve can be observed and avoided. In addition, the shaver should not be put to suction, which may cause important structures to inadvertently be pulled into the shaver and thus injured. Rather, the outflow of the shaver should be put to gravity only.
All patients after elbow arthroscopic debridement should be placed in immediate postoperative range of motion therapy. The two common forms of treatment are static splinting and continuous passive motion. There are currently no studies that demonstrate that one technique is better than another.
References