Hemiarthroplasty in rotator cuff tear arthropathy

RTHROPLASTY IR ROTATOR CUFF TEARARTHROPATHY BARBARA

G. FRIEMAN,

MD, and THOMAS J. ALLARDYCE,

MD

Loss of the stabilizing Rotator cuff tear arthropathy results in a painful glenohumeral joint with poor function. The poor mechanical advantage of effect of the rotator cuff allows superior subluxation of the humeral head. Hemiarthroplasty with a large humeral head the deltoid muscle creates a weak, poorly functioning shoulder. component can relieve pain and retain some of the mechanical advantage of the deltoid by lateralizing the center A larger-than-anatomic humeral head decreases of rotation of the humeral head and regaining deltoid length. Stability is regained by the risk of further superior subluxation of the humeral head by decreasing wear. This article reviews the technique of large head hemiarthroplasty in retensioning the deltoid muscle envelope. this difficult reconstructive problem. KEY WORDS: rotator cuff tear arthropathy, hemiarthroplasty, coracoacromial arch, femodzstion, acetabularization, lateralization of the center of rotation

Rotator cuff tear arthropathy was described by Neer et al in 1983.i They studied a series of patients with pain, weakness, and superior subluxation of the humeral head. A massive rotator cuff tear was always present in this entity. Several investigators before Neer et al’s article had described a spectrum of similar conditions. The rheumatologic literature has concentrated on the biochemical nature of these diseases and the orthopaedic literature has concentrated on the biomechanical nature. In 1981, McCarty et al described an entity he termed “Milwaukee Shoulder” in elderly female patients. This is a destructive arthropathy of the shoulder associated with a massive rotator cuff tear, rupture of the long head of the biceps, and a large joint effusion.’ The joint fluid contains hydroxyapatite crystals, active collagenase, and neutral proteases. On radiographic analysis, this entity is almost identical to rotator cuff tear arthropathy. Rotator cuff tear arthropathy can also be associated with large hemorrhagic joint effusions and sometimes massive synovial hypertrophy, reminiscent of localized rheumatoid arthritis.*t3 It is still not clear whether these are the same disease or different entities. To confuse the picture even more, Milwaukee Shoulder and rotator cuff tear arthropathy occur in the same elderly, predominantly female patient population. It is quite possible that in both of these clinical syndromes, there is some associated neuropathic condition. There is a considerable degree of overlap on physical and radiographic examination between a neuropathic (Charcot) glenohumeral joint and rotator cuff tear arthropathy. It is well

From the Department of Orthopaedic Surgery, Jefferson Shoulder Center, Jefferson Medical College at Thomas Jefferson University Hospital, Philadelphia, PA. Address reprint requests to Barbara G. Frieman, MD, Department of Orthopaedic Surgery, Jefferson Shoulder Center, Jefferson Medical College at Thomas Jefferson University Hospital, 211 S 9th St, Suite 400, Philadelphia, PA 19107. Copyright 0 1994 by W. B. Saunders Company 1048-6666/94/0404-0009$05.00/0

Operative Techniques

in Orthopaedics,

Vol 4, No 4 (October),

documented in the orthopaedic literature that all massive chronic rotator cuff tears do not invariably lead to glenohumeral joint destruction and arthropathy. In fact, only a small percentage of chronic massive rotator cuff tears lead to arthropathy. Therefore, the exact pathophysiology involved in creating true rotator cuff tear arthropathy is not yet well understood.

CLINICAL PRESENTATION patients with rotator cuff tear arthropathy usually present with complaints of weakness, loss of range of active motion, crepitus, and pain in the glenohumeral joint. On radiographic examination, the humeral head is subluxated superiorly because of the superiorly directed force of the deltoid muscle, which is now unopposed by the depressing and compressing effect of the superior rotator cuff muscles. The superior glenoid erodes and forms an arch with the reshaped acromion as described by Arntz et al and Matsen et al.P6 The thickened and sometimes calcified coracoacromial ligament and remodeled acromion now act as the only superior stabilizers of the glenohumeral joint. The long head of the biceps tendon is almost invariably torn but may be medially displaced. The humeral head is held in its superior position by the remaining inferior rotator cuff muscles, which are buttonholed into a more inferior position, supporting the inferior humeral head.‘jG7 The osteopenic humeral tuberosities, biceps tendon, and superior humeral articular cartilage are worn away by the articulation of the humeral head with the coracoacromial arch. The inferior surface of the acromioclavicular joint may be eroded, allowing the glenohumeral joint effusion to communicate into the acrornioclavicular joint, creating a pocket of fluid superior to the acromion and clavicle. Arntz et al and Matsen et al termed this The sculpting of the humeral head “femoralization.“4 concurrent erosion of the coracoacromial arch and supe-

The

1994: pp 253-257

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rior glenoid fossa they termed “acetabularization.“6 The resultant bone-on-bone articulation causes rapid loss of the normal articular cartilage and results in the classic radiographic and hysical findings of rotator cuff tear arthropathy (Fig 1). P Almost all patients with advanced rotator cuff tear arSome patients have retained a thropathy are elderly. surprising amount of active motion, although most patients have significant weakness in both external rotation and elevation. Most patients also have bilateral involvement, even if the opposite shoulder is asymptomatic. Patients may show many months of mild or moderate symptoms before the onset of significant pain, yet radiographic examination is typical of rotator cuff tear arthropathy. Significant pain seems to be a late finding in this Pain occurs at rest but is increased by active disease. Patients with impingement pain attempts at elevation. and large rotator cuff tears without arthropathy will have pain in the impingement zone with elevation and internal However, patients with rotator rotation of the shoulder. cuff tear arthropathy experience pain and crepitus immediately after instituting active elevation of the shoulder. The compression of the worn humeral head into the coracoacromial arch and worn superior glenoid causes imAnother way to differentiate mediate pain and crepitus. rotator cuff tear arthropathy from impingement pain is to have the patient actively lower the arm against gravity

from a position of full forward flexion. In a patient with rotator cuff tear arthropathy, this maneuver causes audible crepitus and severe pain, whereas in patients without arthropathy, pain will occur only in the impingement zone. Patients with rotator cuff tear arthropathy, as well as patients with only massive or large rotator cuff tears without arthropathy, may have severe weakness and tend to drop the arm from an overhead position.

DIFFERENTIAL DIAGNOSIS Rotator cuff tear arthropathy differs from other destructive arthritides of the glenohumeral joint. Osteoarthritis of the glenohumeral joint results in sclerosis of the humeral head with large marginal osteophytes. In osteoarthritis, the rotator cuff is usually intact or reparable, preventing superior migration of the humeral head. Rheumatoid arthritis is associated with a destructive panus, osteopenia, bony erosions, and thin, atrophic rotator cuff tendons. Multiple joint involvement and characteristic laboratory studies differentiate rheumatoid disease from rotator cuff tear arthropathy. However, occasionally rotator cuff tear arthropathy can appear to be a very localized rheumatoid-like disease. Avascular necrosis of the humeral head is not associated with superior instability and is primarily associated with intact rotator cuff tendons and a stable glenohumeral articulation. Chondrolysis and osteolysis associated with infection usually occur with an intact rotator cuff. Aspiration of the joint should clarify the presence of infection. Subluxation and actual dislocation of the joint is a late finding in infections. Both total shoulder arthroplasty and arthrodesis have reportedly relieved pain successfully in rotator cuff tear arthropathy patients.*fG’l However, high rates of glenoid component loosening caused by eccentric loading have been observed in patients who have undergone total shoulder arthroplasty. ‘J’J* Aseptic loosening occurs rapidly when a constrained prosthesis is used.‘* Arthrodesis is of limited use in elderly patients because of the length and difficulty of the postoperative course and limited functional result.6,12P13 Arthrodesis is not useful in patients with bilateral diseases and is now recommended only for patients with unilateral disease and loss of both deltoid and rotator cuff function.12 This article describes the technique of hemiarthroplasty with a modular prosthesis using a large humeral head (26-mm radius x 26 mm, 32 mm or 38 mm height) in patients with rotator cuff tear arthropathy.

INDICATIONS FOR SURGERY

Fig 1. An anteroposterior radiograph of rotator cuff tear arthropathy.

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The primary indication for hemiarthroplasty in rotator cuff tear arthropathy is pain resistant to nonoperative treatment. Hemiarthroplasty can not reliably restore either active function or strength in patients with massive rotator cuff deficiency. A functionally intact deltoid and an intact coracoacromial arch are required for both stab& ity and function in patients being considered for hemiarthroplasty. Because rotator cuff tear arthropathy occurs FRIEMAN AND ALLARDYCE

primarily in elderly patients, the patient’s ability to participate in the postoperative rehabilitation should be assessed before considering surgery. The postoperative functional result is largely dependent on the patient’s willingness and ability to cooperate with the rehabilitation. Regional anesthesia by interscalen block can limit pulmonary compromise and the complications associated with general anesthesia in the elderly population.

TECHNMUE The patient is placed in the beach chair position with the r\S..nm+:.r,3 nhr\r+lrlAr Ax CL,-. ,A,., A cl., ,,#...,G,, c,l.lr. "yx.lu"e Jll"Uluel "II UK CU~jc "I CllC "ycLaLIu~ LL1"IC. The head should be supported on a separate headrest. The arm is draped free and supported on a sterile, padded, narrow support. The anterior delto-pectoral incision is used. The superior rotator cuff and capsule are always absent. The subscapularis tendon is usually torn superiorly, but if most of the tendon is intact, the superior half is released to gain adequate access to the joint. Because the rotator cuff is absent, adequate visualization is achieved by lateral retraction of the deltoid alone. The humeral head is then removed with a saw to the level of the original anatomic insertion of the rotator cuff and to the posterior bald spot. The plane of the cut on the humeral head is determined by aligning these anatomic landmarks with the template of the prosthesis. This recreates the patient’s anatomic humeral retroversion. The long head of the biceps tendon is usually absent. In cases in which it is still present, the tendon should be Fig 3. Drawing showing the abnormal anatomy of the glenohumeral joint from the lateral side.

Fig 2. Drawing showing the diseased glenohumeral joint. The narrow subacromiai spsoc (y) results in shortening of the deltoid envelope (x + y). The medial and superior dlsplacement of the center of rotation is represented by the black dot. ROTATOR CUFF TEAR ARTHROPATHY

tenodesed to the anterior lateral humeral metaphysis. The humeral shaft is then reamed by hand. The bone is frequently osteopenic, and overaggressive reaming can lead to humeral shaft fractures. Because of the usual osteopenia, an ingrowth uncemented prosthesis may not fit securely; therefore, a cemented humeral stem is preferred. Anterior and superior instability can be a problem in these patients. The coracoacromial ligament must be preserved to prevent anterosuperior subluxation. The rounded and worn acromion should be left untouched. The coracoacromial arch is the fulcrum for the motion of the prosthesis and must not be compromised. Any attempt to reshape the superior glenoid or acromion can weaken the remaining subchondral bone and result in accelerated wear and late fracture. The coracoacromial arch may be sclerotic and smooth or very osteopenic and pitted. In either case, the remaining bone and ligament should left intact, minimizing further erosion. When a modular prosthesis is used, the prosthetic head circumference and neck length (height) can be determined with a trial reduction before cementing. A final fitting can be performed after cementing the humeral stem. Hemiarthroplasty in rotator cuff tear arthropathy should accurately retension the remaining soft tissues, primarily the deltoid envelope, to achieve stability within 255

the coracoacromial arch and maximize the mechanical advantage of the deltoid. In theory, the use of a large head hemiarthroplasty should improve the biomechanics of the joint. The larger head should better approximate the normal anatomy that has been destroyed by the disease process. Before using these humeral head components, the surgeon must decide that the rotator cuff musculotendonous unit is truly irreparable. The size of these components physically prevents any attempted repair of the rotator cuff. This leaves the deltoid envelope as the only remaining active stabilizer of the prosthesis. In rotator cuff tear arthropathy, there is medial and superior displacement of the center of rotation of the glenohumeral joint (Fig 2). The deltoid muscle loses its normal convex contour, resulting in dimpling from the humeral shortening and centralization (Fig 2). When viewed from the lateral side (Fig 3), the diseased glenohumeral joint shows the superior subluxated humeral head articulating with the coracoacromial arch. Again, the deltoid muscle loses its normal convex contour and is dimpled anteriorly and posteriorly because of the loss of The large head of the prosthesis volume of the joint. reapproximates the volume of the joint, which has been lost by erosion of the cartilage and bone and retraction of Figure 4 shows the lateralization of the the soft tissues. center of rotation of the joint by the increased humeral head size. The deltoid envelope is tightened by lengthThe distance between the acromion ening the humerus. and the greater tuberosity is restored by replacing the

Fig 5. Drawing of the hemiarthroplasty from the lateral view showing lengthening of the humerus and widening of the articulation.

Fig 4. The large head hemiarthropiasty in position. The center of rotation, in a more normal position, is represented by the black dot. The increase in the subacromial space (y’) results in reestablishing the length of the deltoid envelope (x’ + y’).

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space previously occupied by the rotator cuff tendons with the large head hemiarthroplasty (Fig 4). The anteroposterior contour and the width of the deltoid is also restored. There is a congruous articulation of the oversized prosthetic head with the coracoacromial arch and restoration of humeral length (Fig 5). Therefore, the large head hemiarthroplasty improves the mechanical advantage of the deltoid envelope by increasing its functional length in all planes and re-establishing the center of rotation near its normal position (Fig 4). Stability of the glenohumeral joint is regained not only by retensioning the deltoid envelope, but by increasing the size of the humeral head as well. The enlarged prosthesis is inherently more stable than an anatomically sized prosthesis. To subluxate or dislocate a larger ball, more soft tissue space is required. Arntz et al and Matsen et al advocate choosing a prosthesis that allows approximately 50% posterior subluxation of the glenohumeral joint.& When a larger head prosthesis is used, that degree of subluxation is prevented by the increased volume of the prosthesis. Clinically, the surgeon should attempt to choose the size of prosthesis that fills the void created by abnormal erosion of the glenoid and coracoacromial arch (Fig 6). A nearly congruous fit of the coracoacromial arch, with an improved center of rotation of FRIEMAN AND ALLARDYCE

Fig 6. (A) Drawing showing the abnormal position of the humsraf head whsn the rotator cuff musculotendonous unit is absent. (Is) Tha idsal position of components when a total shouldsr Wwopbty is performed in rotator cuff tear arthrop athy. (C) A larga head hemisrthroplssty articulating with the acromlon and glsnoid in rotator cuff tear arthropathy.

Fig 7. Ant&or-post&or throplasty in posltion.

radlogmph of a large head hsmiar-

ROTATOR CUFF TEAR ARTHROPATHY

the joint, should improve the chances of a good functional result. Once the proper size is chosen, the final prosthesis is articulated and reduced. The deltoid falls in place and the incision is closed cosmetically. There is no attempt to repair the rotator cuff tendons. The delto-pectoral interval usually does not require formal closure. A soft drain is used when necessary. In the recovery room, the patient is started on passive range-of-motion exercises. Active exercises are begun when pain subsides and early healing has occurred, usually between 2 and 4 weeks postoperatively. The prosthesis should articulate with the acromion and the eroded glenoid in a nearly concentric arch (Fig 7). Strength and endurance continues to improve for at least 1 year after surgery. In a preliminary review of 13 patients treated with a large head hemiarthroplasty who were followed-up for more than 1 year, successful relief of pain was achieved in 12 of 13 cases. Active range of motion was maintained or improved in all but one case. Only one patient was disappointed in the results of his surgery, and all patients would elect to have the surgery again. Instability did not occur in any of these patients. The functional results of large head or any type of hemiarthroplasty are unpredictable in rotator cuff tear arthropathy. However, pain relief, the primary goal of surgery, is a predictable result. Further clinical experience and evaluation of this technique is currently underway.

REFERENCES 1. Neer CS, Craig EV, Fukuda H: Cuff tear arthropathy. J Bone Joint Surg [Am] 65:1232-1244, 1983 2. McCarty DJ, Halverson PB, Carrera GR, et al: Milwaukee shoulderAssociation of microspheroids containing hydroxyapatite crystals, active collagenase and neutral protease with rotator cuff defects. I Clinical aspects. Arthritis Rheum 24464473, 1981 3. Halverson PB, Cheung HS, McCarty DJ, et al: Milwaukee shoulderAssociation of microspheroids containing hydroxyapatite crystals, active collagenases, and neutral protease with rotator cuff defects. II Synovial fluid studies. Arthritis Rheum 243474-483, 1981 4. Amtz CT, Matsen FA, Jackins S: Surgical management of complex irreparable rotator cuff deficiency. J Arthroplasty 6:363-370, 1991 5. Amtz CT, Jackins S, Matsen FA: Prosthetic replacement of the shoulder for the treatment of defects in the rotator cuff and the surface of the glenohumeral joint. J Bone Joint Surg [Am] 75:485491, 1993 6. Matsen FA, Amtz CT, Harryman DT: Rotator cuff tear arthropathy, in Bigliani LU (ed): Complications of Shoulder Surgery. Baltimore, MD, Williams and Wilkins, 1993, pp 44-58 7. Pollock RG, Deliz ED, McIlveen SJ, et al: Prosthetic replacement in rotator cuff deficient shoulders. J Shoulder Elbow Surg 1:173-186, 1992 8. Ellman H, Ninnah R, Armstrong H: Experience with the DANA hooded component for cuff deficient shoulder arthroplasty. Orthop Trans 10:217, 1986 9. Fenlin JM, Vaccaro A, Andreychick D, et al: Modular total shoulder: Early experience and impressions. Semin Arthroplasty 1:102-111, 1990 10. Franklin JL, Barrett WP, Jackins S, et al: Glenoid loosening in total shoulder arthroplasty associated with rotator cuff deficiency. J Arthroplasty 3:39-46, 1988 11. Post M: Constrained arthroplasty: Its use and misuse. Semin Arthroplasty 2151-159, 1990 12. Brownlee RC, Cofield RH: Shoulder replacement in cuff tear arthropathy. Orthop Trans 10~230, 1986 13. Brems JJ, Wide AH: Surgical management of cuff tear arthropathy. Orthop Trans 12:729, 1988

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