Adult Reconstruction, 1st Edition

Section III - Shoulder Reconstruction

Part B - Evaluation and Treatment of Shoulder Disorders

43

Glenohumeral Arthritis: Rheumatoid

Joaquin Sanchez-Sotelo

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder with an estimated worldwide prevalence of about 1%. Its prevalence increases starting in the third decade of life; 5% of the population older than 70 years develops RA. Musculoskeletal involvement in RA is characterized by the formation of an erosive synovitis that results in continued bone, cartilage, and soft tissue degradation.

The shoulder is involved in many patients with long-standing RA (Fig. 43-1); some authors have estimated shoulder involvement in about 60% of rheumatoid patients. The condition may affect all the synovial joints of the shoulder region—glenohumeral, acromioclavicular, and sternoclavicular—and the scapulothoracic articulation may become secondarily affected by periscapular fibrosis (Table 43-1). Associated soft tissue involvement is common, and many patients (between 25% and 50% depending on the series) with rheumatoid involvement of the shoulder eventually develop rotator cuff compromise. When the cervical spine is affected, patients may complain of referred pain to the shoulder region.

It is important to remember that pharmacologic treatment of rheumatoid arthritis has continued to improve, and the presentation of patients with RA has changed somewhat owing to the effect of these medications. Some of them are powerful modulators of the immune system that may substantially increase the risk of infection if they are not discontinued prior to surgery. The possibility of rheumatoid involvement and infection coexistence should be taken into consideration. Some patients may also develop shoulder symptoms related to steroid-induced humeral head osteonecrosis.

The purpose of this chapter is to review the evaluation and surgical treatment of glenohumeral rheumatoid arthritis. Physical therapy and steroid injections also play a role in the treatment of shoulder RA. However, multiple steroid injections should be avoided, as they may have a deleterious effect on connective tissue structures. Most physicians suggest limiting injections to three and repeating injections only when significant improvement resulted from the previous injection.

Orthopedic Evaluation of the Rheumatoid Shoulder

Rheumatoid involvement of the shoulder is characterized by pain associated with various degrees of stiffness, weakness, and deformity. Most patients are referred to the orthopedic surgeon for evaluation and treatment of glenohumeral joint involvement. However, the acromioclavicular, sternoclavicular, and scapulothoracic articulations should be evaluated systematically, as failure to address them may lead to incomplete improvement. It is important to assess active and passive range of motion as well as rotator cuff atrophy and strength.

In addition, the shoulder region should be viewed in the context of other joints involved in the upper and lower extremity. Hip, knee, foot, or ankle problems may need to be addressed first if they are symptomatic enough, as well as to decrease the load of crutches or a walker on the upper extremity, especially if rotator cuff repair will be required. Hand and elbow involvement should also be taken into consideration not only to address the most symptomatic joint first and delineate an overall surgical plan for the upper extremity but also to leave room for shoulder and elbow stems should shoulder and elbow arthroplasty both be needed. Finally, all patients undergoing surgical intervention should be evaluated for atlantoaxial instability and temporomandibular involvement (Fig. 43-2).

Radiographic features at presentation will change depending on the stage and severity of rheumatoid involvement. Patients with early synovitis may have minimal radiographic changes, but most patients do present joint line narrowing, osteopenia, and various amounts of erosion and bone loss at the humeral head, glenoid, and coracoacromial arch (Fig. 43-1). Proximal humeral migration may indicate cuff attenuation or tearing.

Glenoid bone stock should be carefully evaluated in every patient with glenohumeral rheumatoid arthritis (Fig. 43-3). Some times plain radiographs clearly show preserved bone stock, but in cases with advanced medial glenoid erosion, a

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CT scan may be helpful for preoperative planning. Shoulder MR should be considered in patients with clinical evidence of rotator cuff involvement but is not needed in every case.

Shoulder Synovectomy

Arthroscopic synovectomy may be indicated in patients with synovitis when the glenohumeral arthritis is not severe enough to warrant shoulder arthroplasty. The indications for synovectomy have decreased as the effectiveness of medical treatment has increased. The severity of synovitis may be evaluated with either MR or arthrography.

This procedure is attractive for several reasons. Arthroscopic surgery provides global access to the entire joint with minimal morbidity, allows a relatively quick recovery, and is associated with a low complication rate. In addition, it provides access not only to the glenohumeral joint but also to the subacromial space and acromioclavicular joint if needed. Associated rotator pathology may be addressed at the time of arthroscopy. Finally, it does not burn any bridges for a later arthroplasty unless it is complicated by a permanent nerve injury or deep infection.

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A complete glenohumeral synovectomy often requires use of at least three portals, as the axillary recess is difficult to reach from the standard posterior and anterosuperior portals. Patients with associated capsule contracture and floating cartilage flaps may benefit from contracture release and cartilage debridement, respectively. Subacromial bursectomy may be required as an isolated or associated procedure; acromioplasty and resection of the coracoacromial ligament are not recommended to avoid weakening of the coracoacromial arch, which may become problematic should cuff attenuation or tearing occur.

Shoulder synovectomy and subacromial bursectomy are more reliable in terms of pain relief than restoration of motion. Interestingly, published reports on the effectiveness of arthroscopic shoulder synovectomy for RA are sparse. Although synovectomy has been proposed to delay progressive joint deterioration, this prophylactic effect has been difficult to prove in clinical practice. The Mayo Clinic experience on arthroscopic shoulder synovectomy was recently reviewed. Sixteen shoulders were followed for a mean of 5.5 years after synovectomy; improvement in pain was noted in 13 patients, with less predictable improvement in motion. Most patients with radiographic follow-up showed disease progression, and worse results were obtained in those patients with more severe radiographic changes at presentation.

Shoulder Arthroplasty

Implant Selection and Surgical Technique

Shoulder arthroplasty is indicated to relieve pain and improve function in patients with symptomatic glenohumeral arthritis that will not respond to other treatment options. Although orthopedic surgeons generally advise delaying joint arthroplasty in other locations or conditions as much as possible, it may be advisable to recommend shoulder arthroplasty sooner rather than later in rheumatoid patients before glenoid bone loss, contractures, and rotator cuff tearing compromise the ability to use a glenoid component or to improve motion and strength.

Nonconstrained total shoulder arthroplasty seems to provide the best results in terms of pain relief and functional restoration. However, glenoid component implantation is contraindicated if glenoid bone stock is insufficient or there is an associated large and irreparable rotator cuff tear. Good results have been reported with both resurfacing and standard humeral components. Uncemented tissue-ingrowth

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humeral components can be used if the metaphyseal bone is intact and if it is possible to achieve adequate diaphyseal contact and fit. However, cemented fixation is advisable in many instances, realizing the potential complications of cement removal from the humeral shaft in rheumatoid patients should revision surgery be needed. When cement is used, it is wise to use antibiotic-loaded polymethylmethacrylate. The use of a reverse shoulder arthroplasty in rheumatoid patients with extensive cuff tearing is controversial; it may provide surprisingly good functional results initially, but the glenoid is oftentimes too osteopenic to allow secure and long-lasting fixation of the glenoid implant.

Several technical aspects should be contemplated at the time of shoulder arthroplasty (Table 43-2). The skin is usually extremely fragile. Local osteopenia may facilitate the occurrence of intraoperative fractures; humeral rotation for exposure should be done carefully, and extension of the deltopectoral approach by deltoid detachment from the acromion and spine of the scapula (the so-called anteromedial approach) is recommended to reduce the risk of fracture in the presence of severe osteopenia and contractures. The rotator cuff should be systematically evaluated and prepared for repair when tears are found. The coracoacromial arch should be preserved intact as a stabilizing mechanism against anterosuperior subluxation in the event of rotator cuff failure.

Although preoperative radiographs and CT scan provide useful information to determine the feasibility of glenoid implantation, the final decision is made at the time of surgery. A hole may be drilled at the glenoid center to estimate the thickness of remaining bone stock; usually, a component can be safely placed if there is at least 2 cm of depth. Central bone loss is more common than peripheral bone loss; however, when segmental bone loss is present, consideration may be given to structural bone graft. A pegged glenoid component is used if possible, as it seems to allow better implant/cement/bone interface (Fig. 43-4); however, keeled glenoid components may allow implantation in situations where loss of bone stock will not allow secure placement of a pegged glenoid component. When glenoid bone stock is insufficient, shoulder hemiarthroplasty is the preferred option.

Humeral head size is selected based on the patient's humeral size as well as stability and motion. When the joint is contracted, it may be necessary to select a smaller humeral head to maintain functional motion. On the other hand, patients with attenuated soft tissues may require a larger humeral head to fill the joint space in the presence of a stretched capsule and rotator cuff tendons.

The rare patient with rheumatoid arthritis whose severe cuff involvement is not associated with severe glenoid bone loss may benefit from a reverse shoulder arthroplasty. The same precautions in terms of exposure and avoidance of undue stresses to decrease the risk of fracture should be taken into consideration. Glenoid reaming should be done carefully, because the glenoid can be easily fractured by a sudden torque if the reamer is trapped against irregular bone.

Postoperative physical therapy follows the general guidelines of shoulder arthroplasty, with sequential passive, active-assisted, and strengthening exercises. Patients who require an associated rotator cuff repair should not start active use of the shoulder for at least 6 weeks. Patients with severely compromised soft tissues and cuff benefit from a limited-goals type of program., Some authors recommend letting the patient immediately return to activities of daily living after a reverse arthroplasty; in patients with rheumatoid arthritis, it is probably best to delay immediate activity for the first 4 weeks with the use of a sling.

Results

Shoulder arthroplasty is associated with pain relief in most rheumatoid patients; functional improvements have not been consistently reported in the literature. When a glenoid component can be safely implanted, total shoulder arthroplasty is associated with a better outcome than with humeral head replacement. Likewise, when an associated cuff tear is found, concomitant cuff repair significantly improves postoperative clinical shoulder scores compared with those of patients in whom tears are not repaired.

The results of a multicenter prospective study were recently published. Thirty-six hemiarthroplasties and 25 total shoulder arthroplasties were followed for a mean of 3 years. The underlying diagnosis was rheumatoid arthritis in 53 shoulders and other inflammatory conditions in the remaining shoulders. Shoulder arthroplasty was associated with a significant improvement in pain and quality

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of life. Motion was also improved, to a mean of 90 degrees with hemiarthroplasty and 115 degrees with total shoulder arthroplasty. Complications included four periprosthetic fractures (two intraoperative), glenoid loosening in two shoulders, and progressive glenoid erosion in four hemiarthroplasties. Other authors have reported a high incidence of rotator cuff tears occurring after shoulder arthroplasty in RA, as well as higher rates of glenoid loosening with longer follow-up.

Resurfacing humeral components avoid the use of a stem, which facilitates the use of stemmed elbow replacement as well as shoulder revision surgery should this become needed. However, humeral head erosion commonly seen in rheumatoid arthritis may compromise fixation of resurfacing components. In addition, glenoid exposure is compromised by the retained humeral head. The published experience of a single institution with this type of component has been satisfactory. These authors studied 33 hemiarthroplasties and 42 total shoulder arthroplasties and reported significant improvements in pain relief, an average flexion gain of about 50 degrees, a high rate of satisfactory results, and only three reoperations for component loosening or progressive glenoid erosion after hemiarthroplasty.

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Reverse shoulder arthroplasty may be considered for patients with glenohumeral arthritis, an associated irreparable cuff tear, and pseudoparalysis. General concerns about glenoid component failure are especially concerning in RA owing to glenoid erosion and osteopenia. Many authors consider RA a relative contraindication for reverse arthroplasty. In a small series of eight rheumatoid shoulders treated with a reverse arthroplasty, the average Constant score improved from 17 to 63 points; there were two cases of glenoid loosening, and three failed acromion osteosynthesis. These findings emphasize the functional improvement that can be expected after reverse arthroplasty as well as the high rate of mechanical failure and other complications.

Rotator Cuff Repair

Isolated cuff repair in patients with rheumatoid arthritis is not very commonly required. Most patients with a cuff tear have associated glenohumeral arthritis and undergo shoulder arthroplasty and cuff repair in the same surgical intervention. However, rheumatoid patients will occasionally present with symptomatic rotator cuff tear and minimal articular changes, and when nonoperative treatment fails, they may be candidates for rotator cuff repair.

The repair of the rotator cuff in rheumatoid patients may be challenging. Some patients have associated stiffness. In addition, the friable nature of the cuff and humeral head osteopenia may compromise the security of open and arthroscopic techniques. Acromioclavicular erosion may debilitate the coracoacromial arch; if acromioplasty is needed, it should be performed carefully, and every effort should be made to preserve the coracoacromial arch.

There is limited published information about the outcome of cuff repair in RA. The Mayo Clinic experience was recently reviewed. Twenty-three repairs were followed for a mean of 10 years or until revision. Tears were partial thickness in nine cases; full-thickness tears were categorized as medium in nine cases, large in four, and massive in one. Surgery provided significant improvements in pain, but motion and strength remained mostly unchanged. No improvement was reported in five cases, three of which underwent reoperation. Full-thickness tears tended to be associated with worse function after surgery. Although pain relief and patient satisfaction may be achieved after surgical repair of rotator cuff tears, functional gains should not be expected when the tear is full thickness.

The Acromioclavicular and Sternoclavicular Joints

When acromioclavicular joint (ACJ) arthritis does not respond to nonoperative treatment, consideration should be given to ACJ synovectomy and resection of the distal end of the clavicle, which may be performed open or arthroscopically. Involvement of the sternoclavicular joint may require synovectomy and rarely resection of the medial end of the clavicle.

Suggested Readings

Barrett WP, Thornhill TS, Thomas WH, et al. Nonconstrained total shoulder arthroplasty in patients with polyarticular rheumatoid arthritis. J Arthroplasty. 1989; 4:91-96.

Collins DN, Harryman DT II, Wirth MA. Shoulder arthroplasty for the treatment of inflammatory arthritis. J Bone Joint Surg 2004; 86A:2489-2496.

Figgie HE III, Inglis AE, Goldberg VM, et al. An analysis of factors affecting the long-term results of total shoulder arthroplasty in inflammatory arthritis. J Arthroplasty. 1988; 3(2):123-130.

Friedman RJ, Thornhill TS, Thomas WH, et al. Non-constrained total shoulder replacement in patients who have rheumatoid arthritis and class-IV function. J Bone Joint Surg. 1989; 71A:494-498.

Kelly IG. Unconstrained shoulder arthroplasty in rheumatoid arthritis. Clin Orthop. 1994; 307:94-102.

Koorevaar RC, Merkies ND, de Waal Malefijt MC, et al. Shoulder hemiarthroplasty in rheumatoid arthritis. 19 cases reexamined after 1-17 years. Acta Orthop Scand. 1997; 68(3):243-245.

Lehtinen JT, Kaarela K, Belt EA, et al. Incidence of glenohumeral joint involvement in seropositive rheumatoid arthritis. A 15 year endpoint study. J Rheumatol. 2000; 27(2):347-350.

McCoy SR, Warren RF, Bade HA III, et al. Total shoulder arthroplasty in rheumatoid arthritis. J Arthroplasty. 1989; 4(2):105-113.

Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructable rotator cuff lesions. J Shoulder Elbow Surg. 2001; 10:17-22.

Rozing PM, Brand R. Rotator cuff repair during shoulder arthroplasty in rheumatoid arthritis. J Arthroplasty. 1998; 13(3):311-319.

Smith AM, Sperling JW, Cofield RH. Rotator cuff repair in patients with rheumatoid arthritis. J Bone Joint Surg. 2005; 87A:1782-1787.

Sneppen O, Fruensgaard S, Johannsen HV, et al. Total shoulder replacement in rheumatoid arthritis: proximal migration and loosening. J Shoulder Elbow Surg. 1996; 5(1):47-52.

Sojbjerg JO, Frich LH, Johannsen HV, et al. Late results of total shoulder replacement in patients with rheumatoid arthritis. Clin Orthop. 1999; 366:39-45.

Stewart MP, Kelly IG. Total shoulder replacement in rheumatoid disease: 7- to 13-year follow-up of 37 joints. J Bone Joint Surg. 1997; 79B:68-72.

Thomas BJ, Amstutz HC, Cracchiolo A. Shoulder arthroplasty for rheumatoid arthritis. Clin Orthop. 1991; 265:125-128.