Case Report

Reverse shoulder arthroplasty as salvage procedure after deltoid muscle flap transfer for irreparable rotator cuff tear: A case report

Shoulder arthroplasty is a safe and durable procedure that provides pain relief, improved range of motion (ROM), and minimal complications for shoulder pain and dysfunction in patients with ipsilateral hemiparesis.

This is a retrospective review of all adult patients who underwent primary reverse total shoulder arthroplasty (RSA) or total shoulder arthroplasty (TSA) in the hemiparetic upper extremity at a single quaternary care academic medical center from 1988 to 2019. Patients were excluded if their neurologic insult was secondary to a spinal-cord injury, cerebral palsy, or inflammatory arthritis, if they underwent a hemiarthroplasty, if they exhibited mild hemiparesis (Medical Research Council Scale of ≥4), or if they had less than 30 days of radiographic follow-up. The primary clinical outcome was revision surgery for any reason. The secondary clinical outcomes included pain using the visual analog scale, ROM via active-assisted manual muscle testing (AAROM), and postoperative complications. The primary radiographic outcome was implant lucency using a standard scale.

A total of 5 shoulders in 5 patients were included, 4 RSAs and 1 TSA with a mean clinical follow-up of 6.2 years (range: 1.42-14.2 years) and mean radiographic follow-up of 3.7 years (range: 31 days-13.5 years). No patient underwent revision surgery. The mean visual analog scale score significantly improved from 7.6 to 1.4 at the last follow-up (P = .005). The mean forward elevation AAROM improved from 27° preoperatively to 88° at the last follow-up (P = .015). There was no significant difference in external rotation at the last follow-up (P = .105). One patient had asymptomatic grade 1 glenoid component lucency with superior subluxation of the humerus after undergoing TSA at a final follow-up of 4.5 years. No other complications were reported.

Shoulder arthroplasty is a durable procedure that provides pain relief, improved AAROM, and minimal complications in patients with ipsilateral hemiparesis. The increase in active-assisted forward elevation ROM can improve caregiver ease with hygiene and dressing. Patients in this study who underwent RSA did not have subsequent glenohumeral dislocation. Larger numbers of patients would be required for adequate power analysis regarding instability in this cohort of patients who may be at risk; our small series did not identify any instability events.

Level IV; Treatment Study

The usual indication for reverse shoulder arthroplasty is glenohumeral arthritis with inadequate rotator cuff and intact deltoid muscle. We report here a case of reverse shoulder arthroplasty using a lattisimus dorsi flap in a patient with deltoid-deficient shoulder following a gunshot injury.

The patient was an otherwise healthy 51-year-old male with a history of gunshot injury of the left shoulder 2006. Upon presentation in 2011, the patient had a loss of most of his shoulder bony and muscular structures. Due to deltoid muscle deficiency, the patient underwent Lattisimus Dorsi muscle flap followed by reverse shoulder arthroplasty in order to establish an upper limb function.

Upon discharge, 11 days after the surgery, the patient was able to achieve 150° flexion and 90° abduction while in the supine position and 45° in each direction, while sitting. He was able to perform internal rotation (behind back) up to the level of the L1 vertebra, assisted active abduction of 90°, and external rotation of 20°. Power tests showed power of grade 4/5 for both shoulder flexion and extension and grade 2+/5 for both abduction and adduction.

At the last follow up one year after the operation, The patient still had passive pain-free full range of motion, but no progress in active range of motion beyond that upon discharge.

Reverse shoulder arthroplasty after Latissmus dori flap in patient with deltoid deficient shoulders can be a successful and reproducible approach to treat such conditions.

Rupture of the anterior and middle deltoid muscle associated with rotator cuff tear arthropathy (RCA) could result in a definitive loss of shoulder function. The purpose of this study was to evaluate clinical outcomes after a concomitant reverse shoulder arthroplasty (RSA) and deltoid repair under these circumstances.

Between 2006 and 2012, 18 consecutive patients with a mean age of 69.7 years, affected by massive irreparable rotator cuff tear and associated dehiscence or rupture of anterior and middle deltoid muscle underwent this operation through a modified anterosuperior approach. Four patients referred a previous shoulder surgery and deltoid tear was iatrogenic. The other 14 cases had an attritional deltoid tears. The average follow-up was 64 months (range 25–121 months).

The mean active anterior elevation passed from a preoperative mean of 53 ± 9.1 (range 45–70) to 132.7 ± 11.6° (85–155°), active external rotation passed from a preoperative mean value of 22.4 ± 3.6° (range 18–26) to an average of 33.7 ± 4.7° (range 30–40°). Mean Constant score increased from 42 ± 6.1 (range 31–51) pre-operatively to 72.3 ± 8.2 (range 57–82) post-operatively. At final review, deltoid contour subjectively was satisfactory to all patients with no palpable defects.

RSA associated with a repair of deltoid tear could be a viable surgical option in cases of tear involving the anterior and middle deltoid associated with a RCA. Patient with a preoperative chronic axillary nerve neuropathy associated with a deltoid muscle tear should be cautioned about the possibility of lower functional outcomes.

Frequently, patients who are candidates for reverse shoulder arthroplasty have had prior surgery that may compromise the anterior deltoid muscle. There have been conflicting reports on the necessity of the anterior deltoid thus it is unclear whether a dysfunctional anterior deltoid muscle is a contraindication to reverse shoulder arthroplasty. The purpose of this study was to determine the 3-dimensional (3D) moment arms for all 6 deltoid segments, and determine the biomechanical significance of the anterior deltoid before and after reverse shoulder arthroplasty.

Eight cadaveric shoulders were evaluated with a 6-axis force/torque sensor to assess the direction of rotation and 3D moment arms for all 6 segments of the deltoid both before and after placement of a reverse shoulder prosthesis. The 2 segments of anterior deltoid were unloaded sequentially to determine their functional role.

The 3D moment arms of the deltoid were significantly altered by placement of the reverse shoulder prosthesis. The anterior and middle deltoid abduction moment arms significantly increased after placement of the reverse prosthesis (P < .05). Furthermore, the loss of the anterior deltoid resulted in a significant decrease in both abduction and flexion moments (P < .05).

The anterior deltoid is important biomechanically for balanced function after a reverse total shoulder arthroplasty. Losing 1 segment of the anterior deltoid may still allow abduction; however, losing both segments of the anterior deltoid may disrupt balanced abduction. Surgeons should be cautious about performing reverse shoulder arthroplasty in patients who do not have a functioning anterior deltoid muscle.