Decreased complication profile and improved clinical outcomes of primary reverse total shoulder arthroplasty after 2010: A systematic review

Anatomic Total Shoulder Arthroplasty Versus Reverse Total Shoulder Arthroplasty in Patients Aged Over 70 Without a Full-Thickness Rotator Cuff Tear: A Systematic Review and Meta-Analysis

Introduction

This systematic review and meta-analysis compared the revision rates, complications, and outcomes in anatomic total shoulder arthroplasty (aTSA) and reverse TSA (rTSA) performed for primary glenohumeral osteoarthritis in patients aged over 70 years without a full-thickness rotator cuff tear.

Materials and Methods

We performed a systematic literature search identifying comparative studies meeting the above patient criteria and published from January 2010 to May 2022 from 3 databases: MEDLINE, EMBASE, and Cochrane Library. We performed the systematic review in accordance with PRISMA guidelines and the study was prospectively registered on PROSPERO.

Results

From the 1798 studies identified from the initial literature search, 4 met our inclusion criteria. Two thousand seven hundred thirty-one shoulder arthroplasties (1472 aTSA and 1259 rTSA) were evaluated with a minimum follow up of 2 years. A statistically significant lower revision rate was observed in rTSA compared to aTSA (odds ratio [OR] 0.50, 95% confidence interval [CI]: 0.30, 0.84, p < .05). No significant difference was noted between aTSA and rTSA in overall complication rate (OR 0.98, 95% CI 0.34, 2.86, p = .97) while aTSA displayed a statistically significant improved postoperative Constant-Murley score [aTSA: 80(75; 82), rTSA: 68(66; 76.5), p < .001].

Conclusion

Higher revision rates were identified following aTSA in our study population, although admittedly this is within retrospective studies. aTSA displayed equal functional results and postoperative complications compared to rTSA in patients over 70 without a full-thickness rotator cuff tear. Given these similar results a shoulder surgeon must carefully consider each patient individually prior to deciding the optimal form of arthroplasty to offer.

Anterosuperior versus deltopectoral approach for primary reverse total shoulder arthroplasty

Aims

The current evidence comparing the two most common approaches for reverse total shoulder arthroplasty (rTSA), the deltopectoral and anterosuperior approach, is limited. This study aims to compare the rate of loosening, instability, and implant survival between the two approaches for rTSA using data from the Dutch National Arthroplasty Registry with a minimum follow-up of five years.

Methods

All patients in the registry who underwent a primary rTSA between January 2014 and December 2016 using an anterosuperior or deltopectoral approach were included, with a minimum follow-up of five years. Cox and logistic regression models were used to assess the association between the approach and the implant survival, instability, and glenoid loosening, independent of confounders.

Results

In total, 3,902 rTSAs were included. A deltopectoral approach was used in 54% (2,099/3,902) and an anterosuperior approach in 46% (1,803/3,902). Overall, the mean age in the cohort was 75 years (50 to 96) and the most common indication for rTSA was cuff tear arthropathy (35%; n = 1,375), followed by osteoarthritis (29%; n = 1,126), acute fracture (13%; n = 517), post-traumatic sequelae (10%; n = 398), and an irreparable cuff rupture (5%; n = 199). The two high-volume centres performed the anterosuperior approach more often compared to the medium- and low-volume centres (p < 0.001). Of the 3,902 rTSAs, 187 were revised (5%), resulting in a five-year survival of 95.4% (95% confidence interval 94.7 to 96.0; 3,137 at risk). The most common reason for revision was a periprosthetic joint infection (35%; n = 65), followed by instability (25%; n = 46) and loosening (25%; n = 46). After correcting for relevant confounders, the revision rate for glenoid loosening, instability, and the overall implant survival did not differ significantly between the two approaches (p = 0.494, p = 0.826, and p = 0.101, respectively).

Conclusion

The surgical approach used for rTSA did not influence the overall implant survival or the revision rate for instability or glenoid loosening.

Implant selection for successful reverse total shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) emerged as a new concept of arthroplasty that does not restore normal anatomy but does restore function. It enables the function of the torn rotator cuff to be performed by the deltoid and shows encouraging clinical outcomes. Since its introduction, various modifications have been designed to improve the outcome of the RTSA. From the original cemented baseplate with peg or keel, a cementless baseplate was designed that could be fixed with central and peripheral screws. In addition, a modular-type glenoid component enabled easier revision options. For the humeral component, the initial design was an inlay type of long stem with cemented fixation. However, loss of bone stock from the cemented stem hindered revision surgery. Therefore, a cementless design was introduced with a firm metaphyseal fixation. Furthermore, to prevent complications such as scapular notching, the concept of lateralization emerged. Lateralization helped to maintain normal shoulder contour and better rotator cuff function for improved external/internal rotation power, but excessive lateralization yielded problems such as subacromial notching. Therefore, for patients with pseudoparalysis or with risk of subacromial notching, a medial eccentric tray option can be used for distalization and reduced lateralization of the center of rotation. In summary, it is important that surgeons understand the characteristics of each implant in the various options for RTSA. Furthermore, through preoperative evaluation of patients, surgeons can choose the implant option that will lead to the best outcomes after RTSA.

Dislocation after reverse total shoulder arthroplasty using contemporary medialized modular systems. Can we still consider it such a frequent complication?

INTRODUCTION

Improvement in reverse total shoulder arthroplasty (RTSA) prosthesis and technique has reduced the initially high complication and revision rates associated with this implant. However, instability continues to be a leading cause of reoperation after RTSA, being related in previous studies with medialized designs. The aim of this study was to determine the dislocation rate with the employment of two medialized modular systems of RTSA in our institution.

MATERIALS AND METHODS

A retrospective review of two different modular systems of RTSA (SMR Modular Shoulder System and Delta XTEND Reverse Shoulder) was performed between 2009 and 2017 with a minimum 3-year follow-up. Baseline demographic, clinical (Constant, ASES and ROM), and radiographic data were collected. Characteristics of postoperative instability cases were also evaluated.

RESULTS

237 primary RTSA (41% SMR/59% Delta) and 34 revision RTSA (44% SMR/56% Delta) with a mean follow-up of 75.6 ± 5.2 months (79.2 SMR/86.3 Delta, p = .586) were included in the present study. Indications for primary RTSA were osteoarthritis, rotator cuff tear arthropathy and massive irreparable rotator cuff tear (64%), acute fracture (32%), and fracture sequelae (4%). Subscapularis tendon was always repaired in degenerative pathology and tuberosities reattached in traumatic cases. The mean age of the global series was 76.5 ± 5.3 years (75.8 SMR/78.6 Delta, p = .104) with a mean Constant/ASES score at final follow-up of 68.5 ± 4.3/72.9 ± 20.3 (71/68 SMR and 69/74 Delta, p = .653 and .642). Only 2 patients (one acute fracture and one fracture sequelae) suffered an early postoperative anterior dislocation (before 3 months) which represents a rate of .84% in primary cases and .73% including revision surgery. Closed reduction manoeuvres were not successful, and both patients required revision surgery. At the end follow-up, both were stable and had no further dislocations.

CONCLUSION

The dislocation rate after RTSA with the employment of two contemporary modular systems with a medialized centre of rotation is extremely low, especially when compared with the previously published series with the original Grammont design. Acute fracture and fracture sequelae were the main diagnoses associated with this instability. The reasons for the low dislocation rate are multifactorial, but the improvement in the baseplate position according to the more recent standards of "ideal position" and technical aspects such as subscapularis repair or tuberosity reattachment in fractures probably play an important role in this aspect.