Gregory P. Nicholson
Rotator cuff–deficient shoulders with degenerative joint disease are a treatment challenge. Most patients will present primarily because of shoulder pain. Shoulder function can be variable even with significant chronic rotator cuff deficiency. The arthritic condition of the shoulder owing to a chronic rotator cuff tear has been termed “cuff tear arthropathy.” This is characterized clinically by pain and poor active motion but with near-normal passive motion. It is most common in women older than the age of 62 years. Many patients are unaware of the condition until the onset of pain. Operative intervention presents a challenge because of the lack of rotator cuff and the degenerative changes present.
Pathogenesis
Etiology
Cuff tear arthropathy (CTA) is an age-related disease. Rotator cuff fiber failure occurs as a result of degenerative processes. This occurs over a period of time. The body adapts as the humeral head elevates through the defect in the rotator cuff and contacts the acromion. The coracoacromial (CA) arch becomes the new fulcrum for the humeral head. Osseous adaptive changes on the humeral head occur with rounding off of the greater tuberosity. The acromion becomes concave, and a new acromiohumeral articulation forms. The patient may have surprisingly little pain, good function, and not know of the condition. The nonphysiologic contact of the humeral head on the acromion and superior glenoid can lead to repeated cartilage and osseous wear with fluid production. Pain and crepitus and loss of function can occur. With further bony erosion and progressive cuff damage, shoulder function may deteriorate.
A seemingly minor trauma can precipitate symptoms in the shoulder. Extension of the pre-existing rotator cuff tear can disrupt the balance of the shoulder that has developed. This can lead to significant pain and loss of function. The degenerative condition was present, but the trauma exposed the vulnerability of the shoulder.
Epidemiology
It is unknown how many patients with rotator cuff tears progress into cuff deficiency and arthropathy. MRI, ultrasound, and cadaver studies have reported rotator cuff tears in the elderly population to be more prevalent with each decade. Some report the presence of rotator cuff tears in 50% of the population older than 70 years of age. Most of these are asymptomatic. There are some estimates that 4% to 5% of patients with rotator cuff tears may progress to a symptomatic CTA from a degenerative cuff tear that is irreparable. Certainly most rotator cuff tears will not progress to a CTA clinical picture. In most series most patients with CTA are women older than 62 years of age. Thus it is a disease that is most prevalent in the seventh and eighth decade of life.
Pathophysiology
Because of the muscle imbalance and superior elevation of the humeral head, and loss of cuff function, there is a progressive degeneration of both rotator cuff substance and bone structure from the humeral head and acromion. The acromion becomes sclerotic and concave. The greater tuberosity becomes rounded off. There is an “acetabularization” of the acromion and a “femoralization” of the humeral head. The superior glenoid also is subjected to increased force from the elevated humeral head. The subacromial bursa becomes thickened and fibrotic. The arthropathic process creates an environment of fluid production, enzyme production, and further degenerative changes.
There are no classification schemes with which to grade the severity of the functional loss, pain, or radiographic changes. There are no studies to correlate the severity of radiographic changes with shoulder function or pain. This
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makes it difficult to communicate about disease severity, treatment options, and success or failure.
Diagnosis
Physical Examination and History
Clinical Features
The patient history is important. History of previous surgery around the shoulder, especially earlier attempts at rotator cuff repair with coracoacromial arch violation, is important to know. A history of trauma such as previous falls, dislocations, or fractures needs to be known. History of inflammatory arthritis, previous infections, gout, and the number of previous steroid injections is important to document. Also the type of medication the patient is on, especially antimetabolites or corticosteroids, is extremely important to document.
Patients will typically present with a progressive loss of motion and strength, with increasing pain. Night pain is common. The ability to use the hand away from the body can be compromised. The patient will have an internal rotation drop sign as the forearm falls into internal rotation when trying to reach or hold out in a handshake-type position. The other presentation will be a minor trauma that results in a significant amount of pain and shoulder dysfunction. The relatively small insult exposes the vulnerability of the affected shoulder.
Physical examination will typically reveal poor active motion and near-normal passive motion (Table 45-1). Visual inspection from behind the patient will reveal degrees of atrophy of the supraspinatus and infraspinatus. There may be a fluid-filled appearance under the deltoid owing to excessive fluid production. Strength testing will elicit weakness in external rotation. Crepitus with both active and passive motion may be noted. All of these findings may be seen with surprisingly little pain. The patients who have very poor active elevation ability (<45 degrees), using mostly a shoulder shrug, and very little if any pain, are termed “pseudoparalytic.” This is a functionally disabling condition. Anterior superior instability with the humeral head riding out from underneath the coracoacromial arch with attempted elevation is important to note.
Radiologic Features
Imaging studies with plain x-ray views are essential (Fig. 45-1). The views obtained should be a true anteroposterior (AP) of the glenohumeral joint, an axillary view, and a scapular Y view (Table 45-2). In patients without advanced osseous changes, a CT scan or MRI scan can be considered. This will give a quantitative and qualitative impression of the size and location of the rotator cuff tear and, more important, the status of the rotator cuff muscle bellies. These studies can provide the surgeon with an assessment for the reparability of a rotator cuff tear. They can also provide qualitative information about the status of the muscle bellies of the cuff muscles. Most patients with advanced rotator cuff tear arthropathy with adaptive and degenerative changes seen on plain films will not require advanced imaging studies such as CT scan or MRI, however.
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TABLE 45-1 Clinical Features of Cuff Tear Arthropathy |
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Figure 45-1 Anteroposterior radiograph of a left shoulder with characteristic cuff tear arthropathy changes: humeral head elevation, adaptive changes on the acromion, and greater tuberosity. There are degenerative joint changes in the glenohumeral joint. |
Radiographically there can be seen a pattern of more superior wear with significant adaptive changes and concavity of the acromion. There can be more of a centralized wear pattern between the humeral head and significant loss of glenoid bone stock. There can also be seen a more massive destructive arthropathy between the humeral head, glenoid, and acromion. It is unclear if these are three different points on the time line of degeneration, or if the shoulder responds differently with differing degenerative patterns to the chronic cuff deficiency. There has been no validated staging or classification of these radiographic changes or of clinical function. To make matters more confusing, not every shoulder with an irreparable rotator cuff tear goes on to painful, symptomatic cuff tear arthropathy.
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TABLE 45-2 Radiographic Features of Cuff Tear Arthropathy |
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Figure 45-2 This patient exhibits anterosuperior instability with attempted active elevation. There was previous rotator cuff repair failure with coracoacromial arch violation. Hemiarthroplasty will not correct the anterosuperior instability. A reverse shoulder replacement is a better option. |
Differential Diagnosis
With the characteristic features of end-stage CTA, it is not hard to make the diagnosis based on history, physical exam, and radiologic findings. Other conditions also need to be considered. The cause of the rotator cuff deficiency leading to the arthritis and shoulder dysfunction is important to know. Other diagnostic possibilities include rheumatoid arthritis, neuropathic arthropathy, septic arthritis, and failed rotator cuff repair with loss of coracoacromial arch containment. Rheumatoid arthritis will usually have multiple joint involvement. Neuropathic arthropathy is most commonly caused by syringomyelia. An MRI of the cervical spine will aid in the diagnosis. Rotator cuff repair failure with anterosuperior instability will be apparent by history of previous surgery, physical exam, and MRI. The patients with multiple failed rotator cuff repair will manifest anterosuperior instability with attempted elevation (Fig. 45-2). The degenerative changes on the humerus, acromion, and glenoid will not be as advanced as those seen with CTA. Function is poor and pain is significant in this population with cuff deficiency and joint injury.
Thus the workup for cuff deficiency with arthritis involves history, physical examination, standard radiographs, blood work to rule out infection or rheumatoid arthritis, and routine blood work. Joint aspiration is rarely indicated unless septic arthritis is suspected.
Treatment
Nonoperative
Conservative management would include a corticosteroid injection to decrease the inflammation and fluid production and to control the pain and allow the patient to rehabilitate. Physical therapy should focus on the structures that are left, which are typically some of the external rotators, some of the internal rotators, and the anterior deltoid. These exercises can be done at home. They should be done without pain, and isometrics and closed chain technique is easiest in the elderly population. This can help patients gain another 5, 10, or 15 degrees of motion and stability. This can be a significant gain for these patients with regard to using the hand away from the body. If pain relief can be maintained, patients can be quite satisfied with these gains. Realistic expectations for active motion, strength, and function should be emphasized to the patient.
Operative Treatment
The primary indication for surgical intervention is pain relief. As stated earlier, the active forward elevation and shoulder function ability of patients in this disease process can be somewhat variable. Some patients have almost no pain but extremely poor function with the inability to actively elevate above the horizontal or even use the hand away from the body at waist height. This patient is much more of a challenge because they have a painless pseudoparalysis of the shoulder. Hemiarthroplasty will not restore active elevation ability in a patient who has pseudoparalysis. Any surgery on cuff tear arthropathy is a limited-goals procedure for pain relief and improved function of the shoulder for activities of daily living. The ability to actively elevate above the horizontal will be unpredictable.
For the patient who has pain that is unresponsive to conservative management and has had no previous coracoacromial arch surgery, and who has active elevation ability of 60 degrees or better, the best treatment option for rotator cuff tear arthropathy seems to be hemiarthroplasty. There is no advantage to total shoulder arthroplasty with resurfacing of the glenoid in an unconstrained shoulder design. Bipolar shoulder hemiarthroplasty has poorer active elevation ability than hemiarthroplasty. Arthrodesis is poorly tolerated in the elderly population and is not recommended.
Hemiarthroplasty has shown the ability to predictably relieve pain in cuff tear arthropathy. Functional ability, specifically active elevation, has been less predictable, however. At best, patients and surgeons should expect active elevation on the average to be approximately 90 degrees. With longer follow-up, hemiarthroplasty has shown progressive bone changes in the acromion and glenoid. These changes have correlated with increasing pain and decreasing function. It is unclear why some patients do better than others with regard to active elevation and shoulder function. No prognostic factor has been identified to correlate with a better functional result. However, it is quite clear that poorer results are associated with those patients who had prior rotator cuff surgery and coracoacromial arch violation. If there has been coracoacromial arch violation, hemiarthroplasty is not indicated, as anterosuperior instability will result.
Reverse shoulder arthroplasty was approved for use in the United States in 2004. It had been used in Europe for >8 years. The reverse shoulder arthroplasty is indicated for cuff deficiency and joint injury when no other satisfactory option is available (Table 45-3). Specific indications
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include CTA with a pseudoparalysis clinical picture. If there is extremely poor active elevation, hemiarthroplasty will not predictably restore elevation ability. If there has been previous coracoacromial arch violation or there is anterosuperior instability of the humeral head, then reverse is a better option. If there is a failed hemiarthroplasty for CTA or fracture, then reverse is a better option. In age-matched populations with CTA and no previous surgery, the reverse arthroplasty achieved an average of 40 degrees greater active forward elevation compared with hemiarthroplasty. The reverse provides for the potential for better active elevation ability. However, both internal and external rotation can be limited owing to the constraint of the reverse design.
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TABLE 45-3 Indication for Reverse Shoulder Arthroplasty |
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Reverse shoulder arthroplasty is indicated for those patients who have had multiple failed rotator cuff repair attempts with violation of the coracoacromial arch and present with pain, poor function, and anterior superior instability. It should also be considered in those patients with pseudoparalysis and extremely poor active motion. Those patients with an extremely thin acromion or an acromial insufficiency fracture should also be considered candidates for reverse shoulder arthroplasty.
Operative Technique
The operative technique for arthroplasty in cuff tear arthropathy begins with a thorough preoperative evaluation. The vast majorities of these patients are elderly, older than 62 years of age, and have comorbidities. Positioning is important. The patient should be moved to the lateral edge of the operating room table. The operative arm should be able to be brought off the side of the table for gentle extension, external rotation, and adduction to dislocate the humeral head forward. The head and neck need to be supported. The shoulder and arm are draped free for maximum flexibility and position.
A deltopectoral approach is used so as not to violate the anterior deltoid. The cephalic vein can be taken laterally with the deltoid or medially with the pectoralis major according to the surgeon's preference. Extensive bursal material will be encountered under the deltoid and under the clavipectoral fascia lateral to the strap muscles off the coracoid. This material should be debrided. The subscapularis should be incised off the lesser tuberosity. The subscapularis should be tagged with sutures and reflected medially.
At this point, the humeral head is very gently dislocated. These patients are typically females older than 65 years of age with osteopenic bone. Great care should be taken to gently distract the arm and put a flat retractor behind the humeral head; with extension, adduction, and external rotation the humeral head is brought forward. The humeral head should be osteotomized with an oscillating saw. Careful reaming of the humeral canal should be performed owing to osteopenic bone. In the vast majority of these cases, the humeral stem is cemented into place. Also, cement will stabilize the proximal aspect of the humerus and support sutures that are placed through the anterior anatomic neck for subscapularis reattachment.
Humeral prosthetic head size and position are chosen. General guidelines can be thought of as choosing a humeral head size that will fill the existing coracoacromial arch (Fig. 45-3). It is helpful to have a prosthetic head that allows approximately 50% of posterior translation on the glenoid. With the arm in approximately 70 degrees of abduction, at least 40 degrees of internal rotation of the arm should occur.
The subscapularis is repaired to the lesser tuberosity after relocation of the new prosthesis in the joint. A drain may or may not be used underneath the deltoid. In many patients, because of the amount of bursal material and fluid production that needed to be debrided, there can be significant dead space. A drain for 24 hours may prevent a collection of a hematoma. The deltopectoral interval is then
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tacked closed with absorbable sutures. The subcutaneous tissue is closed with absorbable sutures and then the skin closed by surgeon preference. A supportive sling and swathe device can be applied.
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Figure 45-3 Hemiarthroplasty for cuff tear arthropathy. Note that the prosthetic head size fills the arch of the upper glenoid and coracoacromial arch without overstuffing the joint. |
Aftercare
Patients after hemiarthroplasty for cuff tear arthropathy should be supported in a sling. Passive range of motion should begin on the first postoperative day with pendulum exercises. Passive external rotation with a limit of 30 degrees, passive forward elevation with a limit of approximately 90 degrees, and pulley exercises should be instituted. The patient is encouraged to use the hand, wrist, and elbow for activities of daily living within the sling. After 1 month, the sling can be discontinued and active assisted range of motion can begin. Isometric strengthening for the muscle groups that are still workable are instituted. These include the external rotators, all three heads of the deltoid, and the scapular rotators. At the end of 2 months, light resistive exercises with resistive exercise bands should be instituted for the external rotators, the internal rotators, and all three heads of the deltoid. Patients should be informed both preoperatively and postoperatively that this will be a prolonged and slow rehabilitation. They will not reach their best or maximum potential for approximately 6 months after the operation.
Results to be Expected from Hemiarthroplasty for Cuff Tear Arthropathy
Multiple studies have documented the predictable pain relief that hemiarthroplasty can provide to patients who have unremitting pain from the degenerative changes of arthritis with cuff deficiency. This has also been shown to be the most consistent when there have not been previous attempts at rotator cuff repair or acromioplasty/coracoacromial arch violation type surgery. The average active forward elevation that patients can expect from a hemiarthroplasty for cuff tear arthropathy is approximately 90 degrees. Most studies have 2-year follow-up, but longer-term follow-up studies are being reported. These studies show that there is progressive bony erosion of the acromion and superior glenoid and that these erosions correlate with pain and decreasing function over the longer periods of time.
Operative Technique for Reverse Shoulder Arthroplasty
The operative technique for reverse shoulder arthroplasty is through the deltopectoral approach. It has also been described through the superior approach by incising the deltoid off the anterior acromion and repairing the deltoid. The technical considerations are to obtain exposure to the glenoid that is not needed in hemiarthroplasty. The humeral head is resected, and the glenoid component is placed in the inferior aspect of the glenoid. The inferior capsule needs to be elevated off the glenoid rim and the glenoid component placed inferiorly. The component should be placed at neutral or at best a slight inferior tilt. These technical tips can avoid scapular notching inferiorly. The humeral component is placed in approximately 10 degrees of retroversion. The myofascial sleeve tension should allow the humeral component to reduce under the glenoid with a 1- to 2-mm push-pull action. The strap muscles will be under tension. The humerus should be cemented.
Aftercare for the reverse is similar to the hemiarthroplasty; however, the author rarely has patients do formal therapy after a reverse shoulder arthroplasty. A sling is used for 3 to 4 weeks. Patients are allowed to do activities of daily living in the sling immediately. Closed chain exercises for the anterior deltoid and isometrics for external and internal rotation are begun. The reverse will allow the scapula to function more efficiently, and patients progress very well on their own with surgeon direction.
In a comparison study with follow-up >3 years follow-up, patients with no prior shoulder surgery and CTA were treated either with hemiarthroplasty or reverse shoulder arthroplasty. The patients with reverse shoulder arthroplasty had 40 degrees greater active forward elevation for an average of 138 degrees, and the Constant score was 20 points higher than for those patients with hemiarthroplasty. There were no cases of glenoid loosening requiring revision. The hemiarthroplasties had more than one third of the cases with progressive bone erosion in the superior glenoid and acromion with increasing pain.
Complications
Complications of hemiarthroplasty for cuff deficiency begin with the fact that these are elderly patients and have
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comorbidities. Medical problems can be exacerbated by surgery in the elderly. The unpredictable function results, especially with regard to strength and active forward elevation, make it imperative that a discussion occurs with the patient to avoid unrealistic expectations. One of the complications that has recently been seen after 4- to 5-year follow-up is the bone erosion that is progressive at the superior glenoid and the undersurface of the acromion that correlates with increasing pain and decreasing function (Fig. 45-4).
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Figure 45-4 Hemiarthroplasty with progressive superior glenoid erosion. Increasing pain and decreasing function were noted by the patient. |
Complications of the reverse arthroplasty include dislocation, hematoma formation, infection, implant failure, and scapular notching inferior to the glenoid component. The complication rate is higher than with hemiarthroplasty, but these complications do not seem to affect the results of the operation. Glenoid loosening has been rare, but is a concern with longer-term follow-up.
Summary
Cuff tear arthroplasty is a disabling condition of the shoulder found in elderly patients. It is variable in its presentation with regard to the extent of degenerative osseous change in the glenoid, humeral head, and acromion. It is variable in its presentation with regard to preoperative active elevation ability and pain level. The overriding indication for operative intervention in cuff tear arthropathy is pain relief.
Suggested Readings
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Favard L, Lautmann S, Sirveaux F, et al. Hemiarthroplasty versus reverse arthroplasty in the treatment of osteoarthritis with massive rotator cuff tear. In: Walch G, Boileau P, Mole D, eds. 2000 Shoulder Prostheses. … Two to Ten Year Follow-up. Montpelier, France: Sauramps Medical; 2001:261-268.
Neer CS II, Craig EV, Fukuda H. Cuff-tear arthropathy. J Bone Joint Surg. 1983; 65A:1232-1244.
Pollock RG, Deliz ED, McIlveen SJ, et al. Prosthetic replacement in rotator cuff-deficient shoulders. J Shoulder Elbow Surg. 1992; 1:173-186.
Sanchez-Sotelo J, Cofield RH, Rowland CM. Shoulder hemiarthroplasty for glenohumeral arthritis associated with severe rotator cuff deficiency. J Bone Joint Surg. 2001; 83A:1814-1822.
Werner CML, Steinmann PA, Gilbart M, et al. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg. 2005; 87A:1776-1786.
Zuckerman JD, Scott AJ, Gallagher MA. Hemiarthroplasty for cuff tear arthropathy. J Shoulder Elbow Surg. 2000; 9:169-172.