Review Question - QID 219999

The patient has advanced rotator cuff arthropathy, which would be appropriately treated with a reverse total shoulder arthroplasty (RTSA). A polyethylene glenoid component (Answer 4) is a feature of an anatomic total shoulder arthroplasty, which is contraindicated for use in the setting of a chronic rotator cuff tear.

Rotator cuff tear arthropathy results from long-standing rotator cuff disease that contributes to loss of normal concavity compression, resulting in superior humeral migration with acetabularization of the acromion and femoralization of the humeral head. In these patients, anatomic total shoulder arthroplasty is contraindicated, as persistent edge loading due to the lack of normal glenohumeral biomechanics results in glenoid loosening and early implant failure. Reverse total shoulder arthroplasty, conversely, remains the workhorse in treating late-stage rotator cuff arthropathy with glenohumeral arthritis.

Ahearn et al. reviewed the influence of rotator cuff pathology other than full-thickness tears on functional outcomes in total shoulder replacement (TSR). The authors retrospectively reviewed case notes and MRIs of patients undergoing TSR for primary glenohumeral osteoarthritis over 4 years, dividing them into three groups based upon their preoperative MRI findings: (1) normal rotator cuff, (2) the presence of tendinopathy within the rotator cuff, or (3) the presence of a partial thickness rotator cuff tear. They reported on 43 patients and found that there was no statistically significant difference between the results obtained for the three groups with regard to either the Oxford Shoulder Score or quick-DASH, leading them to conclude that even in the presence of rotator cuff tendinopathy or partial tearing, TSR is an efficacious treatment option for patients with primary glenohumeral osteoarthritis in the medium term.

Smith et al. reviewed the modern use of the extended humeral head (cuff tear arthropathy) hemiarthroplasty. The authors note that the treatment of osteoarthritis in the rotator cuff-deficient population is largely dominated by reverse total shoulder arthroplasty (RTSA); however, the authors propose that extended humeral head hemiarthroplasty may provide a less invasive alternative for select patients with cuff tear arthropathy (CTA) and preserved glenohumeral active elevation. They conclude that CTA hemiarthroplasty may be used if the following conditions are satisfied: (1) preserved elevation > 90°, (2) maintained stability (intact coracoacromial ligament), and (3) desire to circumvent the complications associated with RSA.

Figure A is an AP radiograph of the shoulder showing advanced rotator cuff arthropathy with superior migration of a femoralized humeral head and acetabularization of the acromion.

Incorrect Answers:
Answer 1: Though convertible platform stems are primarily used with anatomic total shoulder components to allow for simpler conversion to an RTSA prosthesis without humeral component extraction, using a convertible stem is not contraindicated for the initial treatment of cuff tear arthropathy.
Answer 2: Using a glenoid baseplate with either a central post or screw are both acceptable options for glenoid preparation of an RTSA prosthesis.
Answer 3. The correct procedure for this patient is an RTSA, which medializes the center of rotation of the components compared to the native glenohumeral joint in order to improve the mechanical advantage of the deltoid for forward elevation.
Answer 5: Short cementless stems are acceptable options for patients with osteopenic bone. In patients with severe osteoporosis or a low deltoid tuberosity index concerning for poor proximal humeral bone quality, cemented stems can be used.