A multicenter study: postoperative complications of reverse total shoulder arthroplasty

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Reverse shoulder arthroplasty with preservation of the rotator cuff for primary glenohumeral osteoarthritis has similar outcomes to anatomic total shoulder arthroplasty and reverse shoulder arthroplasty for cuff arthropathy.

Reported early complication rates in reverse total shoulder arthroplasty have widely varied from 0% to 75% in part due to a lack of standard inclusion criteria. In addition, it is unclear whether revision arthroplasty is associated with a higher rate of complications than primary arthroplasty. We therefore (1) determined the types and rates of early complications in reverse total shoulder arthroplasty using defined criteria, (2) characterized an early complication-based learning curve for reverse total shoulder arthroplasty, and (3) determined whether revision arthroplasties result in a higher incidence of complications. From October 2004 to May 2008, an initial series of 200 reverse total shoulder arthroplasties was performed in 191 patients by a single surgeon. Forty of the 200 arthroplasties were revision arthroplasties. Of these, 192 shoulders were available for minimum 6-month followup (mean, 19.4 months; range, 6-49.2 months). We determined local and systemic complications and distinguished major from minor complications. Nineteen shoulders involved local complications (9.9%), including seven major and 12 minor complications. Nine involved perioperative systemic complications (4.7%), including eight major complications and one minor complication. The local complication rate was higher in the first 40 shoulders (23.1%) versus the last 160 shoulders (6.5%). Seven of 40 (17.5%) revision arthroplasties involved local complications, including two major and five minor complications compared to 12 of 152 (7.9%) primary arthroplasties, including five major and seven minor complications. Nerve palsies occurred less frequently in primary arthroplasties (0.6%) compared to revisions (9.8%). The early complication-based learning curve for reverse total shoulder arthroplasty is approximately 40 cases. There was a trend toward more complications in revision versus primary reverse total shoulder arthroplasty and more neuropathies in revisions. Level IV, therapeutic study. See the guidelines online for a complete description of level of evidence.

Reverse shoulder arthroplasty has higher perioperative implant complications and transfusion rates than total shoulder arthroplasty

Reverse total shoulder arthroplasty changes the lines of action of the shoulder muscles, resulting in increases in the moment arms of the major abductors and flexors of the glenohumeral joint; however, at present little is known about the axial rotation capacity of the musculature after this procedure. The purpose of this study was to measure the instantaneous axial rotation moment arms of all of the major muscles spanning the glenohumeral joint during abduction and flexion after reverse total shoulder arthroplasty. Reverse total shoulder arthroplasty was performed on eight entire cadaveric upper extremities. Specimens were mounted onto a testing apparatus, and the internal/external rotation moment arms of eighteen major muscle subregions involving the subscapularis, supraspinatus, infraspinatus, teres minor, teres major, deltoid, pectoralis major, and latissimus dorsi were measured during abduction and flexion. These muscle moment arms were compared with those measured preoperatively in the anatomical shoulders (i.e., before the arthroplasty). Reverse total shoulder arthroplasty resulted in loss of external rotation function in the posterior deltoid subregion. Postoperatively, the inferior subscapularis subregion had the largest internal rotation moment arm overall, whereas the teres minor and the inferior infraspinatus subregion had the greatest external rotation moment arms. The teres minor, infraspinatus, and deltoid subregions were external rotators during abduction, whereas only the teres minor, infraspinatus, and to a small extent the posterior deltoid subregion were external rotators during flexion. Reverse total shoulder arthroplasty results in an overall decrease in the external rotation moment arm of the deltoid and increases in the moment arms of the major internal rotators, including the latissimus dorsi and pectoralis major. Reverse total shoulder arthroplasty may result in complete loss of external rotation function if the teres minor and infraspinatus muscles are damaged.

Fractures of the acromion and the scapular spine are established complications of reverse shoulder arthroplasty (RSA), and when they occur, the continuous strain by the deltoid along the bony fragments makes healing difficult. Evidence on treatment specific outcomes is poor, making the definition of a gold standard fixation technique difficult. The purpose of this systematic review is to assess whether any particular fixation construct offers improved clinical and/or radiographic outcomes. A systematic review of the literature on fixation of acromial and scapular spine fractures following RSA was carried out based on the guidelines of PRISMA. The search was conducted on PubMed, Embase, OVID Medline, and CENTRAL databases with strict inclusion and exclusion criteria applied. Methodological quality assessment of each included study was done using the modified Coleman methodology score to asses MQOE. Selection of the studies, data extraction and methodological quality assessment was carried out by two of the authors independently. Only clinical studies reporting on fixation of the aforementioned fractures were considered. Fixation construct, fracture union and time to union, shoulder function and complications were investigated. Nine studies reported on fixation strategies for acromial and scapular spine fractures and were therefore included. The 18 reported results related to fractures in 17 patients; 1 was classified as a Levy Type I fracture, 10 as a Levy Type II fracture and the remaining 7 fractures were defined as Levy Type III. The most frequent fixation construct in type II scapular spine fractures was a single plate (used in 6 of the 10 cases), whereas dual platin was the most used fixation for Levy Type III fractures (5 out of 7). Radiographic union was reported in 15 out of 18 fractures, whereas 1 patient (6.7%) had a confirmed non-union of a Levy Type III scapular spine fracture, requiring revision fixation. There were 5 complications reported, with 2 patients undergoing removal of metal and 1 patient undergoing revision fixation. The Subjective Shoulder Value and Visual Analogue Scale pain score averaged 75% and 2.6 points, respectively. The absolute Constant Score and the ASES score averaged 48.2 and 78.3 points, respectively. With the available data, it is not possible to define a gold standard surgical fixation but it seems that even when fracture union can be achieved, functional outcomes are moderate and there is an increased complication rate. Future studies are required to establish a gold standard fixation technique.

Comparison of reverse shoulder arthroplasty and total shoulder arthroplasty for patients with inflammatory arthritis.

Subscapularis insufficiency and the risk of shoulder dislocation after reverse shoulder arthroplasty

* The most common indication for reverse total shoulder arthroplasty is primary rotator cuff tear arthropathy.* Indications for reverse total shoulder arthroplasty have expanded beyond rotator cuff tear arthropathy to include other pathologies such as irreparable rotator cuff tears, glenohumeral arthritis with an intact rotator cuff, acute proximal humeral fractures, the sequelae of proximal humeral fractures, neoplasms of the proximal part of the humerus, inflammatory arthropathies, and failed total shoulder arthroplasty and hemiarthroplasty.* Reverse total shoulder arthroplasty continues to have high rates of complications, which include instability, infection, scapular notching, neurologic injury, and component loosening, among others.

There are few reports on the revision or reintervention of reverse total shoulder arthroplasty (RTSA) in South Korea. The purpose of this study was to evaluate the true incidence of complications and reintervention of RTSA and clinical and radiological outcomes based on our 14-year experience in RTSA in a Korean population. Between March 2008 and June 2022, 412 consecutive cases of RTSA were performed in 388 patients with an average age of 74.4 years at our institute. Excluding 23 patients lost to follow-up, 365 patients (373 shoulders including 8 bilateral cases) who underwent primary RTSA with more than 6 months of follow-up were enrolled in this study. We evaluated those who had complications or reintervention including revision RTSA for failed RTSA. Patient charts were reviewed, and clinical outcomes including clinical scores, complications, and reintervention and radiologic outcomes were evaluated at the last follow-up. Among the 373 shoulders that underwent primary RTSA, complications were found in 50 patients (13.94%, 10 men and 40 women with a mean age of 75.9 ± 6.7 years [range, 51-87 years]). The causes of complications were as follows: 13 acromion, coracoid, or scapular spine fractures, 10 loosening (glenoid: 5, humeral stem: 5), 5 infections, 4 periprosthetic fractures, 2 instability, 2 neurologic complications, and 14 miscellaneous complications. Twenty patients (5.63%, 4 men and 16 women with a mean age of 74.2 ± 8.2 years [range, 51-87 years]) underwent reintervention. The interval to the first reintervention was 27.8 ± 23.1 months (range, 0.1-78 months). The causes of reintervention (20 cases) were 8 loosening (glenoid: 4, humeral stem: 4), 5 infections, 5 fractures, and 2 instability. Among them, 15 component revisions (4.02%) were performed. At the last follow-up, American Shoulder and Elbow Surgeons, University of California at Los Angeles, and Simple Shoulder Test scores were improved from 25.4, 12.4, and 1.6 preoperatively to 40.4, 16.2, and 3.2, respectively. Forward flexion (48° to 87°), abduction (52° to 79°), external rotation (18° to 22°), and internal rotation (buttock to L2) were improved. After primary RTSA in a Korean population, the complication, reintervention, and revision rates were 13.94%, 5.63%, and 4.02%, respectively. Careful evaluation of the complications and adequate treatments should be performed.

Glenoid lateralization influences active internal rotation after reverse shoulder arthroplasty.

Operative treatment of acromial and scapular spine fracture nonunions complicating reverse total shoulder arthroplasty

Management of the cuff-deficient arthritic shoulder has long been challenging. Early unconstrained shoulder arthroplasty systems were associated with high complication and implant failure rates. The evolution toward the modern reverse shoulder arthroplasty includes many variables of constrained shoulder arthroplasty designs. This review explores the development of reverse shoulder arthroplasty, specifically describing (1) the evolution of reverse shoulder arthroplasty designs, (2) the biomechanical variations in the evolution of this arthroplasty, and (3) the current issues relevant to reverse shoulder arthroplasty today. Using a PubMed search, the literature was explored for articles addressing reverse shoulder arthroplasty, focusing on those papers with historical context. Results of the early designs were apparently poor, although they were not subjected to rigorous clinical research and usually reported only in secondary literature. We identified a trend of glenoid component failure in the early reverse designs. This trend was recognized and reported by authors as the reverse shoulder evolved. Authors reported greater pain relief and better function in reverse shoulder arthroplasty with the fundamental change of Grammont's design (moving the center of rotation medially and distally). However, current reports suggest lingering concerns and challenges with today's designs. The history of reverse shoulder arthroplasty involves the designs of many forward-thinking surgeons. Many of these highly constrained systems failed, although more recent designs have demonstrated improved longevity and implant performance. Reverse shoulder arthroplasty requires ongoing study, with challenges and controversies remaining around present-day designs.

Scapular notching is a unique complication of Grammont-style reverse total shoulder arthroplasty. While reverse total shoulder arthroplasty has revolutionized the treatment of pseudoparalysis secondary to cuff tear arthropathy, the implications of scapular notching with regard to patient function and implant stability remain unclear. We reviewed literature to determine the etiology and incidence, radiographic progression and effect on implant stability, relationship with postoperative function, and risk factors for the development of scapular notching. We reviewed PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE with the terms "reverse total shoulder arthroplasty" and "scapular notching." Inclusion criteria were a level of evidence of IV (or better). Twenty-four articles were selected after manual review. Scapular notching after reverse total shoulder arthroplasty is due to repetitive contact between the polyethylene of the humeral component and the inferior scapular neck during adduction, leading to erosion of the scapular neck, polyethylene wear, joint inflammation, and potential implant loosening. Scapular notching appears between 6 and 14 months postoperatively, with an incidence of 44% to 96%. Radiographic progression and effect on patient function remain controversial. Predictors of scapular notching include surgical approach, glenoid wear, preoperative diagnosis, infraspinatus muscle quality, cranial-caudal positioning, and tilt of the glenosphere. Improved understanding of the etiology and risk factors for scapular notching will lead to refinement in implant technology and surgical technique that may translate into improved patient function and implant longevity for Grammont-style reverse total shoulder arthroplasty.

Background: Long-term clinical and radiographic outcome data after standard cemented long-stem reverse shoulder arthroplasty (RSA) remain underreported. The aim of this study is to report on medium- to long-term data of patients over 60 years of age. Methods: The same type of RSA (Aequalis Reverse II, Memphis, TN, USA) was implanted in 27 patients with a mean age of 73 years (range 61–84). Indications for RSA were cuff tear arthropathy (CTA) in 25 cases and osteoarthritis (OA) in two cases. Pre- and postoperative Constant Score was assessed and component loosening, polyethylene wear, scapular notching and revision rates were recorded at a mean clinical follow-up (FU) of 127.6 months (SD ± 33.7; range 83–185). Results: The mean-adjusted CS (aCS) improved from 30.0 (range 10–59) to 95.0 (range 33–141) points (p < 0.001). Glenoid loosening was found in two (9.1%) and stem loosening was found in three (13.6%) cases. Polyethylene wear was observed in four (18.2%) cases. Scapular notching appeared in 15 (68.2%) cases but was not associated with poor aCS (p = 0.423), high levels of pain (p = 0.798) or external rotation (p = 0.229). Revision surgery was necessary in three (11.1%) cases. Conclusions: RSA with a cemented standard long stem leads to improvement in forward elevation, abduction and pain after a mean FU of 10 years. However, external rotation does not improve with this prosthetic design. Moreover, scapular notching is observed in the majority of cases, and revision rates (11.1%) as well as humeral loosening rates (13.6%) remain a concern. Level of evidence: Level 4, retrospective cohort study.