Review Question - QID 218015

This older patient has chronic, deep shoulder pain and limited overhead movement, with radiographic signs of rotator cuff arthropathy. Given his age and minimal-moderately active lifestyle, he would be best treated with a reverse total shoulder arthroplasty (rTSA; Figure F).

Rotator cuff arthropathy is a specific form of shoulder arthritis that develops secondary to the abnormal biomechanical forces on the glenohumeral joint secondary to chronic rotator cuff insufficiency. The supraspinatus and infraspinatus muscular forces normally depress the humeral head caudally and serve as dynamic stabilizers to maintain the humeral head centrally within the shallow glenoid socket. Loss of these muscular forces results in superior migration of the humeral head (i.e. decreased acromiohumeral interval), predictable arthritic changes on radiographs, and significant pain/dysfunction in patients. Initial treatment includes conservative management with lifestyle modifications, physical therapy, and corticosteroid injections. If patients fail to achieve adequate pain relief with restoration of function specific to their individual needs, operative intervention should be considered. Younger patients may be treated with rotator cuff repair, superior capsular reconstruction, or even hemiarthroplasty (HA). Older patients with less active lifestyles have been shown to have superior outcomes when treated with rTSA.

Leung and colleagues performed a retrospective review comparing the functional outcomes of HA vs rTSA for the treatment of rotator cuff arthropathy at their institution. They identified 20 HA and 36 rTSA patients (~60-70 years old) with a mean follow-up of 4.4 years and 3 years, respectively. At the final follow-up, rTSA showed better functional outcome scores, greater range of motion, and similar complication rates (25%) when compared to HA. The authors concluded that rTSA performs better than hemiarthroplasty in terms of pain relief, function, and active elevation at a 2-year follow-up.

Young and colleagues performed a matched cohort analysis comparing the functional outcomes of HA vs rTSA for the treatment of rotator cuff arthropathy using the New Zealand Joint Registry. After matching patients for age, sex, and general comorbidities, they found 102 patients (mean age 72 years) for each group. The rTSA group had higher functional outcome scores and fewer revisions with no difference in mortality at the 6-month follow-up. The authors concluded that rTSA resulted in superior outcomes to hemiarthroplasty, however, long-term follow-up is needed.

Figure A displays a right shoulder with a decreased acromiohumeral interval (i.e. superior migration of the humeral head) indicative of rotator cuff arthropathy when corroborated with this patient’s history and physical examination. Figure B displays metal suture anchors adjacent to the lateral edge of the humeral head articular surface, indicative of a single-row rotator cuff repair. Figure C displays a shoulder hemiarthroplasty. Figure D displays a stemless anatomic total shoulder arthroplasty. A radiopaque marker line can be appreciated within the glenoid, which is commonly employed in the manufacturing of newer all-polyethylene glenoid baseplates. Figure E displays a stemmed anatomic total shoulder arthroplasty that lacks the radiopaque marker on the glenoid baseplate. Figure F displays a short-stemmed reverse total shoulder arthroplasty.

Incorrect Answers:
Answer 1: Given the patient’s age and chronicity of disease (indicated by radiographic degenerative changes), it is unlikely that a rotator cuff repair would successfully heal and provide comparable outcomes to that of reverse total shoulder arthroplasty. Rotator cuff repair should be considered in patients without end-stage radiographic changes, who have more active lifestyles, and who have minimal fatty infiltration of rotator cuff musculature on MRI evaluation.
Answer 2: Shoulder hemiarthroplasty can be considered in younger patients with irreparable rotator cuff tears. While hemiarthroplasty can provide reliable pain relief, reverse total shoulder arthroplasty functional outcomes have consistently outperformed those of hemiarthroplasty in rotator cuff arthropathy among older individuals.
Answer 3 and 4: Rotator cuff arthropathy leads to non-concentric motion placed on the glenoid component in anatomic total shoulder arthroplasty with eccentrically loaded edges classically referred to as the “rocking horse phenomenon.” This results in eventual glenoid component loosening (#1 cause for the need for revision), and therefore patients with chronic rotator cuff tears and cuff arthropathy are best served with hemiarthroplasty (young patients) or rTSA (older patients), respectively.