Dislocation following reverse total shoulder arthroplasty

Mitigating the Risk of Instability After Reverse Shoulder Arthroplasty: A Critical Analysis Review of Patient and Surgical Factors

» Instability and dislocation after reverse shoulder arthroplasty may occur in up to 31% of patients.

» Clinical risk factors for instability include younger age, male sex, increased body mass index, preoperative diagnosis of proximal humerus fracture or rotator cuff pathology, history of instability of the native shoulder or after surgery, and a medical history of Parkinson's disease.

» Patients with rheumatoid arthritis and decreased proximity to the coracoid may also be at greater risk.

» In patients at a high risk of instability, surgeons should consider a more lateralized prosthesis (particularly in patients with an incompetent rotator cuff), repairing the subscapularis (particularly when using a medialized prosthesis), and upsizing the glenosphere (>40 mm in male and 38-40 mm in female patients).

» While potentially useful, less evidence exists for the use of a constrained liner (particularly with a lateralized glenosphere and/or in low-demand patients) and rotating the polyethylene liner posteriorly to avoid impingement.

Impact of accumulating risk factors on the incidence of dislocation after primary reverse total shoulder arthroplasty using a medial glenoid-lateral humerus onlay prosthesis

BACKGROUND

The aim of this study was to facilitate preoperative identification of patients at risk for dislocation after reverse total shoulder arthroplasty (rTSA) using the Equinoxe rTSA prosthesis (medialized glenoid, lateralized onlay humerus with a 145° neck-shaft angle) and quantify the impact of accumulating risk factors on the occurrence of dislocation.

METHODS

We retrospectively analyzed 10,023 primary rTSA patients from an international multicenter database of a single platform shoulder prosthesis and quantified the dislocation rate associated with multiple combinations of previously identified risk factors. To adapt our statistical results for prospective identification of patients most at-risk for dislocation, we stratified our data set by multiple risk factor combinations and calculated the odds ratio for each cohort to quantify the impact of accumulating risk factors on dislocation.

RESULTS

Of the 10,023 primary rTSA patients, 136 (52 female, 83 male, 1 unknown) were reported to have a dislocation for a rate of 1.4%. Patients with zero risk factors were rare, where only 12.7% of patients (1268 of 10,023) had no risk factors, and only 0.5% of these (6 of 1268) had a report of dislocation. The dislocation rate increased in patient cohorts with an increasing number of risk factors. Specifically, the dislocation rate increased from 0.9% for a patient cohort with 1 risk factor to 1.0% for 2 risk factors, 1.6% for 3 risk factors, 2.7% for 4 risk factors, 5.3% for 5 risk factors, and 7.3% for 6 risk factors. Stratifying dislocation rate by multiple risk factor combinations identified numerous cohorts with either an elevated risk or a diminished risk for dislocation.

DISCUSSION

This multicenter study of 10,023 rTSA patients demonstrated that 1.4% of the patients experienced dislocation with one specific medialized glenoid-lateralized humerus onlay rTSA prosthesis. Stratifying patients by multiple combinations of risk factors demonstrated the impact of accumulating risk factors on the incidence of dislocation. rTSA patients with the greatest risk of dislocation were those of male sex, age ≤67 years at the time of surgery, patients with body mass index ≥31, patients who received cemented humeral stems, patients who received glenospheres having a diameter >40 mm, and/or patients who received expanded or laterally offset glenospheres. Patients with these risk factors who are considering rTSA using a medial glenoid-lateral humerus should be made aware of their elevated dislocation risk profile.

Does glenoid inclination affect the anterior stability of reverse total shoulder arthroplasty? A biomechanical study

PURPOSE

The anterior stability of reverse total shoulder arthroplasty is affected by multiple factors. However, the effect of glenosphere inclination on stability has rarely been investigated, which is what this study aims to look into.

METHODS

Reverse shoulder arthroplasty was performed on 15 cadaveric human shoulders. The anterior dislocation forces and range of motion in internal rotation in the glenohumeral joint (primary measured parameters) were tested in a shoulder simulator in different arm positions and implant configurations, as well as with a custom-made 10° inferiorly inclined glenosphere. The inclination and retroversion of the baseplate as well as the distance between the glenoid and coracoid tip in two planes (secondary measured parameters) were evaluated on CT scans.

RESULTS

In biomechanical testing, the custom-made inclined glenosphere showed no significant influence on anterior stability other than glenoid lateralisation over all arm positions as well as the neck-shaft angle in two arm positions. The 6 mm lateralised glenosphere reduced internal rotation at 30° and 60° of glenohumeral abduction. In 30° of glenohumeral abduction, joint stability was increased using the 155° epiphysis compared with the 145° epiphysis. The mean inclination was 16.1°. The inclination was positively, and the distance between the glenoid and coracoid tip in the anterior-to-posterior direction was negatively correlated with anterior dislocation forces.

CONCLUSIONS

The custom-made inferiorly inclined glenosphere did not influence anterior stability, but baseplate inclination itself had a significant effect on stability.

Managing rotator cuff tear arthropathy: a role for cuff tear arthropathy hemiarthroplasty as well as reverse total shoulder arthroplasty

BACKGROUND

Disabling cuff tear arthropathy (CTA) is commonly managed with reverse shoulder arthroplasty (RSA). However, for patients with CTA having preserved active elevation, cuff tear arthropathy hemiarthroplasty (CTAH) may offer a cost-effective alternative that avoids the complications unique to RSA. We sought to determine the characteristics and outcomes of a series of patients with CTA managed with these procedures.

MATERIALS AND METHODS

We retrospectively reviewed 103 patients with CTA treated with shoulder arthroplasty, the type of which was determined by the patient's ability to actively elevate the arm. Outcome measures included the change in the Simple Shoulder Test (SST), the percent maximum improvement in SST (%MPI), and the percentage of patients exceeding the minimal clinically important difference for the change in SST and %MPI. Postoperative x-rays were evaluated to assess the positions of the center of rotation and the greater tuberosity for each implant.

RESULTS

Forty-four percent of the 103 patients were managed with CTAH while 56% were managed with RSA. Both arthroplasties resulted in clinically significant improvement. Patients having RSA improved from a mean preoperative SST score of 1.7 (interquartile range [IQR], 0.0-3.0) to a postoperative score of 6.3 (IQR, 2.3-10.0) (P < .01). Patients having CTAH improved from a preoperative SST score of 3.1 (IQR, 1.0-4.0) to a postoperative score of 7.6 (IQR, 5.0-10.) (P < .001). These improvements exceeded the minimal clinically important difference. Instability accounted for most of the RSA complications; however, it did not account for any CTAH complications. The postoperative position of the center of rotation and greater tuberosity on anteroposterior radiographs did not correlate with the clinical outcomes for either procedure.

CONCLUSION

For 103 patients with CTA, clinically significant improvement was achieved with appropriately indicated CTAH and RSA. In view of the lower cost of the CTAH implant, it may provide a cost-effective alternative to RSA for patients with retained active elevation.

Baseplate inferior offset affects shoulder range of motion in reverse shoulder arthroplasty in Asian population

BACKGROUND

Impingement is a common complication of reverse shoulder arthroplasty. Placement of the baseplate with a wide impingement-free angle is ideal; however, there are few studies on Asian populations, which have smaller height and physique, and there is a lack of guidance on achieving optimal outcomes. The purpose of the present study was to explore the impingement-free range of motion reverse shoulder arthroplasty and analyze the suitable baseplate position or tilt for the Asian population using simulation software.

METHODS

We uploaded computed tomography scan data from 20 Asian patients to three-dimensional (3D) simulation software. The implantation of the reverse shoulder arthroplasty component was performed on the 3D humerus and scapula using software, and range of motion was assessed until impingement occurred.

RESULTS

The range of motion in flexion significantly improved when the baseplate was lowered up to 3 mm inferiorly. Range of motion in abduction and internal and external rotation significantly improved as the baseplate was lowered up to 4 mm. There was no significant difference in range of motion in any motion after changing the inferior tilt, except in internal and external rotation.

CONCLUSIONS

The range of motion in abduction, flexion, and internal and external rotations significantly improved with increased inferior offset. These results may prove valuable in determining the optimal baseplate position for RSA, particularly in Asian populations.

Impact of constrained humeral liner on impingement-free range of motion and impingement type in reverse shoulder arthroplasty using a computer simulation

BACKGROUND

Dislocation is a major complication of reverse total shoulder arthroplasty (RSA). The humeral liner may be changed to a constrained type when stability does not improve by increasing glenosphere size or lateralization with implants, and patients, particularly women with obesity, have risks of periprosthetic instability that may be secondary to hinge adduction on the thorax, but there are few reports on its impact on the range of motion (ROM). This study aimed to determine the influence of humeral liner constraint on impingement-free ROM and impingement type using an RSA computer simulation model.

METHODS

A virtual simulation model was created using 3D measurement software for conducting a simulation study. This study included 25 patients with rotator cuff tears and rotator cuff tear arthropathy. Impingement-free ROM and impingement patterns were measured during flexion, extension, abduction, adduction, external rotation, and internal rotation. Twenty-five cases with a total of 4 patterns of 2 multiplied by 2, making a total of 100 simulations: glenosphere (38 mm normal type vs. lateralized type) and humeral liner constraint (normal type vs. constrained type). There were 4 combinations: normal glenosphere and normal humeral liner, normal glenosphere and constrained humeral liner, lateralized glenosphere and normal humeral liner, and lateralized glenosphere and constrained humeral liner.

RESULTS

Significant differences were found in all impingement-free ROM in 1-way analysis of variance (abduction: P = .01, adduction: P < .01, flexion: P = .01, extension: P = .02, external rotation: P < .01, and internal rotation: P < .01). Tukey's post hoc tests showed that the impingement-free ROM was reduced during abduction, external rotation, and internal rotation with the combination of the normal glenosphere and constrained humeral liner compared with the other combinations, and improved by glenoid lateralization compared with the combination of the lateralized glenosphere and constrained humeral liner. In the impingement pattern, the Pearson χ2 test showed significantly greater proportion of impingement of the humeral liner into the superior part of the glenoid neck in abduction occurring in the combination of the normal glenosphere and constrained humeral liner group compared with the other groups (P < .01). Bonferroni post hoc tests revealed that the combination of the normal glenosphere and constrained humeral liner was significantly different from that of the lateralized glenosphere and constrained humeral liner (P < .01). Using constrained liners resulted in early impingement on the superior part of the glenoid neck in the normal glenosphere, whereas glenoid lateralization increased impingement-free ROM.

CONCLUSION

This RSA computer simulation model demonstrated that constrained humeral liners led to decreased impingement-free ROM. However, using the lateralized glenosphere improved abduction ROM.

Predictors of dislocations after reverse shoulder arthroplasty: a study by the ASES complications of RSA multicenter research group

BACKGROUND

Instability after reverse shoulder arthroplasty (RSA) is one of the most frequent complications and remains a clinical challenge. Current evidence is limited by small sample size, single-center, or single-implant methodologies that limit generalizability. We sought to determine the incidence and patient-related risk factors for dislocation after RSA, using a large, multicenter cohort with varying implants.

METHODS

A retrospective, multicenter study was performed involving 15 institutions and 24 American Shoulder and Elbow Surgeons members across the United States. Inclusion criteria consisted of patients undergoing primary or revision RSA between January 2013 and June 2019 with minimum 3-month follow-up. All definitions, inclusion criteria, and collected variables were determined using the Delphi method, an iterative survey process involving all primary investigators requiring at least 75% consensus to be considered a final component of the methodology for each study element. Dislocations were defined as complete loss of articulation between the humeral component and the glenosphere and required radiographic confirmation. Binary logistic regression was performed to determine patient predictors of postoperative dislocation after RSA.

RESULTS

We identified 6621 patients who met inclusion criteria with a mean follow-up of 19.4 months (range: 3-84 months). The study population was 40% male with an average age of 71.0 years (range: 23-101 years). The rate of dislocation was 2.1% (n = 138) for the whole cohort, 1.6% (n = 99) for primary RSAs, and 6.5% (n = 39) for revision RSAs (P < .001). Dislocations occurred at a median of 7.0 weeks (interquartile range: 3.0-36.0 weeks) after surgery with 23.0% (n = 32) after a trauma. Patients with a primary diagnosis of glenohumeral osteoarthritis with an intact rotator cuff had an overall lower rate of dislocation than patients with other diagnoses (0.8% vs. 2.5%; P < .001). Patient-related factors independently predictive of dislocation, in order of the magnitude of effect, were a history of postoperative subluxations before radiographically confirmed dislocation (odds ratio [OR]: 19.52, P < .001), primary diagnosis of fracture nonunion (OR: 6.53, P < .001), revision arthroplasty (OR: 5.61, P < .001), primary diagnosis of rotator cuff disease (OR: 2.64, P < .001), male sex (OR: 2.21, P < .001), and no subscapularis repair at surgery (OR: 1.95, P = .001).

CONCLUSION

The strongest patient-related factors associated with dislocation were a history of postoperative subluxations and having a primary diagnosis of fracture nonunion. Notably, RSAs for osteoarthritis showed lower rates of dislocations than RSAs for rotator cuff disease. These data can be used to optimize patient counseling before RSA, particularly in male patients undergoing revision RSA.

Impact of Surgeon Case Volume on Outcomes After Reverse Total Shoulder Arthroplasty

INTRODUCTION

Despite a rapid increase in utilization of reverse total shoulder arthroplasty (rTSA), volume-outcome studies focusing on surgeon volume are lacking. Surgeon-specific volume-outcome studies may inform policymakers and provide insight into learning curves and measures of efficiency with greater case volume.

METHODS

This retrospective cohort study with longitudinal data included all rTSA cases as recorded in the Centers for Medicare & Medicaid Services Limited Data Set (2016 to 2018). The main effect was surgeon volume; this was categorized using two measures of surgeon volume: (1) rTSA case volume and (2) rTSA + TSA case volume. Volume cutoff values were calculated by applying a stratum-specific likelihood ratio analysis.

RESULTS

Among 90,318 rTSA cases performed by 7,097 surgeons, we found a mean annual rTSA surgeon volume of 6 ± 10 and a mean rTSA + TSA volume of 9 ± 14. Regression models using surgeon-specific rTSA volume revealed that surgery from low (<29 cases) compared with medium (29 to 96 cases) rTSA-volume surgeons was associated with a significantly higher 90-day all-cause readmission (odds ratio [OR], 1.17; confidence interval [CI], 1.10 to 1.25; P < 0.0001), higher 90-day readmission rates because of an infection (OR, 1.46; CI, 1.16 to 1.83; P = 0.0013) or dislocation (OR, 1.43; CI, 1.19 to 1.72; P = 0.0001), increased 90-day postoperative cost (+11.3% CI, 4.2% to 19.0%; P = 0.0016), and a higher transfusion rate (OR, 2.06; CI, 1.70 to 2.50; P < 0.0001). Similar patterns existed when using categorizations based on rTSA + TSA case volume.

CONCLUSION

Surgeon-specific volume-outcome relationships exist in this rTSA cohort, and we were able to identify thresholds that may identify low and medium/high volume surgeons. Observed volume-outcome relationships were independent of the definition of surgeon volume applied: either by focusing on the number of rTSAs performed per surgeon or anatomic TSAs performed.

LEVEL OF EVIDENCE

III.

Incidence of complications related to shoulder arthroplasties identified on computed tomography

PURPOSE

Determine incidence of shoulder arthroplasty complications identified on computed tomography (CT).

MATERIALS AND METHODS

Retrospective institutional database review of patients with shoulder arthroplasties who underwent CT between 01/2006-11/2021 at a tertiary academic referral center with subspecialized orthopedic shoulder surgeons. CT reports were reviewed for arthroplasty type and complication. Data were stratified and summarized. Associations between complications and arthroplasty types were determined with Chi-squared goodness of fit test.

RESULTS

Eight hundred twelve CTs in 797 unique patients were included (438 (53.9%) females and 374 (46.1%) males; mean age 67 ± 11 years). There were 403 total shoulder arthroplasties (TSA), 317 reverse total shoulder arthroplasties (rTSA), and 92 hemiarthroplasties (HA). Complications were present in 527/812 (64.9%) and incidences were: loosening/aseptic osteolysis 36.9%, periprosthetic failure 21.6%, periprosthetic fracture 12.3%, periprosthetic dislocation 6.8%, joint/pseudocapsule effusion 5.9%, prosthetic failure 4.8%, infection 3.8%, and periprosthetic collection 2.1%. Complications per arthroplasty were: 305/403 (75.7%) TSAs, 176/317 (55.5%) rTSAs, and 46/92 (50%) HAs (p < 0.001). Periprosthetic fracture (20.8%), prosthetic dislocation (9.8%), and prosthetic failure (7.9%) were highest in rTSAs (p < 0.001, p < 0.013, p < 0.001, respectively). Loosening/aseptic osteolysis most frequent in TSAs (54.1%) (p < 0.001). Periprosthetic failure most frequent in HA (32.6%) (p < 0.001). Significant associations were identified with joint/pseudocapsule effusion and loosening/aseptic osteolysis (p = 0.04) and prosthetic dislocation (p < .001).

CONCLUSION

In this single tertiary academic referral center cohort, the incidence of shoulder arthroplasty complication identified on CT was 64.9% and the most commonly occurring complication was loosening/aseptic osteolysis (36.9%). TSA had the highest incidence of complication (75.7%).

Active physical therapy does not improve outcomes after reverse total shoulder arthroplasty: a multi-center, randomized clinical trial

OBJECTIVE

To compare range of motion (ROM) and patient-reported outcomes (PROs) between a structured home exercise program (HEP) and active, supervised physiotherapy (PT) after primary Reverse total shoulder arthroplasty (RTSA) by performing a multicenter randomized clinical trial.

METHODS

Patients undergoing primary RTSA at 2 centers were randomized to either a HEP group, in which they were given a handout and a rope pulley, or a PT group, in which they were given a standardized prescription. Surgical technique and implants were standardized. At baseline, 6 weeks, 3 months, and 1 year postoperatively, we obtained American Shoulder and Elbow Surgeons scores, Western Ontario Osteoarthritis Scores, visual analogue scale for pain scores, and measured ROM via videotape. On video, ROM was then measured by blinded observers. At all study visits, patients were asked how many days per week they were in PT and how many days a week they completed HEP to determine compliance and crossover. An a priori power analysis suggested 29 patients per group, 56 patients total to detect a difference of 30° in active forward elevation with a power of 0.8 at a 2-sided alpha of 0.05.

RESULTS

89 patients were randomized, 43 to PT, and 46 to HEP. We obtained 1-year PRO follow-up on 83 patients (93%) and ROM follow-up on 73 patients (82%). Nine patients (20%) crossed over from HEP to PT and 2 patients (4%) crossed over from PT to HEP. Complications occurred in 13% of HEP and 17% of PT patients (P = .629). Using mixed models that account for baseline values, there were no significant differences between groups in PROs or ROM at final follow-up.

CONCLUSION

In this 2-center, randomized clinical trial, there were no significant differences in patient outcomes or ROM between HEP and PT after RTSA. These findings suggest that it may not be necessary to recommend PT as a protocol for all patients after RTSA.

How common is nerve injury after reverse shoulder arthroplasty? A systematic review

BACKGROUND

Nerve injury following reverse shoulder arthroplasty (RSA) is a known risk factor with wide ranging incidences reported. This systematic review evaluates the overall incidence of nerve injury following primary and revision RSA and summarizes the characteristics of the nerve injuries reported in the current literature.

METHODS

A systematic review was performed using separate database searches (Pubmed, Embase, Web of Science, Cochrane) following the PRISMA guidelines. Search criteria included the title terms "reverse shoulder," "reverse total shoulder," "inverted shoulder," and "inverted total shoulder" with publication dates ranging from 01/01/2010 to 01/01/2022. Studies that reported neurological injuries and complications were included and evaluated for primary RSA, revision RSA, number of nerve injuries, and which nerves were affected.

RESULTS

After exclusion, our systematic review consisted of 188 articles. A total of 40,146 patients were included, with 65% female. The weighted mean age was 70.3 years. The weighted mean follow-up was 35.4 months. The rate of nerve injury after RSA was 1.3% (510 of 40,146 RSAs). The rate of injury was greater in revision RSA compared to primary RSA (2.4% vs. 1.3%). Nerve injury was most common in RSAs done for a primary diagnosis of acute proximal humerus fracture (4.0%), followed by cuff tear arthropathy (3.0%), DJD (2.6%), and inflammatory arthritis (1.7%). Massive rotator cuff tears and post-traumatic arthritis cases had the lowest nerve injury rates (1.0% and 1.4%, respectively). The axillary nerve was the most commonly reported nerve that was injured in both primary and revision RSA (0.6%), followed by the ulnar nerve (0.26%) and median nerve (0.23%). Brachial plexus injury was reported in 0.19% of overall RSA cases.

CONCLUSION

Based on current English literature, nerve injuries occur at a rate of 1.3% after primary RSA compared with 2.4% after revision RSA. The most common nerve injury was to the axillary nerve (0.64%), with the most common operative diagnosis associated with nerve injury after RSA being acute proximal humerus fracture (4.0%). Surgeons should carefully counsel patients prior to surgery regarding the risk of nerve injury.

Intraoperative and early postoperative complications of reverse shoulder arthroplasty: A current concepts review

Background

Reverse shoulder arthroplasty is a common procedure performed for a variety of shoulder pathologies.

Aims and objectives

This current concept review evaluates the intraoperative and early postoperative complications, with a specific focus given to neurological and vascular injury, fracture, dislocation and venous thromboembolism.

Conclusion

A detailed knowledge of potential complications will allow surgeons to mitigate risk and maximise outcomes.

Cause analysis of the liner dissociation of a customized reverse shoulder prosthesis based on finite element analysis

Background: Dissociation of the polyethylene liner after reverse shoulder arthroplasty could cause shoulder dislocation that could not achieve closed reduction. The cause of liner dissociation is currently unclear.

Method: Non-homogeneous model of the bone was constructed and dynamic finite element analysis was utilized to simulate the impingement of the polyethylene liner and scapula during humeral adduction. The stress distribution of the fixation claws, their degree of deformation (DOD), and the stress of the impingement sites in three initial humeral postures (neutral, 30° flexion, and 30° extension) were measured and analyzed. The influence of the liner material stiffness was also investigated.

Result: The impingement stress on the liner and scapula was 100–200 MPa, and different humeral postures caused different locations of impingement points. The fixation claws’ maximum principal stress (MPS) results were below 5 MPa. In the connection area between some fixation claws and the liner, compressive stresses on the inside and tensile stresses on the outside were observed, which showed that the fixation claws were prone to deform toward the center direction. The maximum DOD results of three initial humeral postures (neutral, 30° flexion, and 30° extension) were 3.6%, 2.8%, and 3.5%, respectively. The maximum DOD results of neutral initial humeral posture were 0.51% and 11.4% when the elastic modulus of the liner was increased and decreased by a factor of 10, respectively.

Conclusion: The humeral adduction impingement could lead to the deformation of the claw-shaped liner fixation structure, which might be one of the reasons for the liner dissociation. The increased stiffness of the liner material helped to reduce the deformation of the fixation structure.

Risk Factors for Dislocation After Reverse Total Shoulder Arthroplasty: A Systematic Review and Meta-Analysis

Instability after reverse total shoulder arthroplasty (RTSA) is a dreaded complication. Risk factors for postoperative instability are uncertain. The goal of this systematic review was to quantitatively and qualitatively analyze the risk factors for instability after RTSA. Of 1183 studies identified, 12 studies involving 3810 patients were included. The mean age was 68.8 years, and the mean follow-up was 46 months. The pooled rate of dislocation after RTSA was 4.0%. Several patient-specific and implant-specific risk factors have been identified, and especially the implant-specific risk factors appear avoidable with current knowledge, implant design, and technology. [Orthopedics. 2022;45(6):e303-e308.].

Risk factors of instability following reverse total shoulder arthroplasty in patients with no history of shoulder surgery

Introduction

As its indications expand, reverse total shoulder arthroplasty (rTSA) utilization continues to increase. Though relatively uncommon, instability following rTSA can be associated with significant morbidity and need for subsequent revision and treatment. This case control study aims to characterize factors leading to instability after rTSA, especially in those with no previous shoulder surgery.

Methods

194 rTSAs performed within the study period with appropriate operative indications and follow-up were included. Risk factors used in analysis included age, gender, BMI, ASA class, Charlson comorbidity index (CCI), glenosphere, tray, and liner size. Data was analyzed using a hierarchical binary logistical regression to create a predictive model for instability.

Results

Seven patients sustained a post-operative dislocation. Mean time to dislocation was 60.4 weeks. Five required open reduction with placement of either a larger humeral tray or polyethylene spacer. One required open reduction with osteophyte removal, and one was converted to a resection arthroplasty. Dislocators were more likely to have a larger BMI (p = 0.002), higher ASA classification (p = 0.09), and larger liner size (p = 0.01).

Conclusion

This study demonstrates a large series of patients successfully treated with rTSA. Dislocations were an uncommon complication, but were clearly associated with higher patient BMI, ASA classification, and increased liner size.

[Cuff Arthropathy - Inverse Total Shoulder Arthroplasty (iSTEP) - Biomechanical Principles, Complications and Outcomes]

The inverse total shoulder prosthesis is a standard treatment for cuff arthropathy. The number of implanted inverse total shoulder prostheses in Germany is significantly higher than that of the anatomical total shoulder prosthesis. Kaplan-Meier analyses show a 10-year result of inverse total shoulder prostheses after cuff arthropathy of 90%. The extent of the scapular notching correlates with the functional clinical outcome. The humeral anchoring principles of inverse total shoulder prosthesis differ considerably (from purely epiphyseal to diaphyseal). Inverse total shoulder prostheses show significant differences in humeral and glenoid offset as well as in shaft-neck angles. The large number of systems available differ considerably concerning anatomical and biomechanical parameters - the surgeons must be trained accordingly. Still, most shoulder replacements are implanted by surgeons who rarely perform this procedure.

The role of subscapularis repair following reverse shoulder arthroplasty: systematic review and meta-analysis

PURPOSE

Inadequate subscapularis repair has been advocated as one of the contributing factors for dislocation in reverse total shoulder arthroplasty; nonetheless the need to restore the subscapularis tendon integrity is under debate. The aim of this systematic review was to answer the question: does subscapularis reattachment following reverse total shoulder arthroplasty improve joint stability, range of motion and functional scores?

METHODS

The literature was systematically screened in accordance with PRISMA guidelines looking for papers evaluating clinical outcomes of reverse total shoulder arthroplasty in relation to the management of subscapularis tendon. Studies comparing clinical outcomes, complications and dislocation rate with or without subscapularis repair were included. Studies in which reverse total shoulder arthroplasty was performed for trauma or tumors were excluded. The methodology of included articles was scored with MINORS scale and the Risk of Bias was assessed adopting the ROBINS-I (Risk Of Bias In Non-randomized Studies of Interventions) developed by the Cochrane Group. A meta-analysis was also performed combining the studies to increase the sample size and hence the power to obtain meaningful data.

RESULTS

The database search identified 1062 records, and 6 full-text articles were finally included. A total number of 1085 reverse total shoulder arthroplasty were assessed on. Except for one study, lateralized prosthetic designs have been used. Dislocation occurred in 0.8% (5/599 patients) of the patient with repaired subscapularis and in 1.6% (8/486 patients) of the tenotomized patients, and subscapularis repair was not associated with a higher risk of dislocation (pooled Peto OR: 0.496, 95% CI: 0.163 to 1.510, p = 0.217). Qualitative assessment revealed no differences in the range of motion and clinical scores.

CONCLUSION

Subscapularis repair after reverse total shoulder arthroplasty produces no clinically meaningful benefits, particularly using lateralized prosthetic designs. Subscapularis re-attachment does not improve implant stability, nor increases range of motion or clinical scores. Given these results, keeping in mind the antagonistic effect of the repaired subscapularis on external rotation, no evidence lead to suggest subscapularis reattachment following reverse total shoulder arthroplasty with lateralized prosthetic designs.

Acromiohumeral cerclage in reverse total shoulder arthroplasty for recurrent instability

BACKGROUND

Recurrent shoulder instability after reverse total shoulder arthroplasty (rTSA) presents a challenging clinical problem. A handful of cases have been reported describing stability achieved only after revision rTSA with cerclage augmentation. We describe an acromiohumeral cerclage technique, where the humeral component is fixed with a nonabsorbable, high-tensile suture tape looped through transosseous acromial drill tunnels as an augment to salvage shoulder stability.

METHODS

All patients treated with acromiohumeral cerclage in rTSA for instability between November 1, 2015, and February 1, 2020, with minimum 1-year follow-up were included. Demographic information, baseline preoperative and postoperative range of motion at most recent follow-up, American Shoulder and Elbow Surgeons (ASES) shoulder scores, and visual analog scale (VAS) scores were recorded and compared.

RESULTS

Ten patients, 4 female and 6 male, aged 64.3 ± 7.4 years (range, 53-77 years) with the mean postoperative follow-up of 23 months were included; 90% underwent surgery on the dominant side. Patients underwent an average of 2.1 ± 1.9 prior revisions (range, 0-7), over an average of 10.4 months (range, 0-72 months), before revision with suture cerclage augmentation was performed. All patients either had significant past shoulder history at other institutions and/or comorbidities that added significant complexity to their cases, with an average of 0.6 ± 0.9 (range, 0-3) prior other shoulder operations performed before their initial rTSA. The average decrease in VAS score among the 10 patients was 4.3 ± 2.7 (P < .05), ranging from 0 to 8 points. The average increase in ASES score was 51.3 ± 21 (P < .05), ranging from 13.3 to 69.9 points. The average increase in active forward elevation for 8 patients was 79° ± 39° (P = .0008), ranging from 40° to 160°. All patients have remained stable with well-positioned prostheses since their final operations with no recurrent dislocations or acromial complications. Two patients unable to travel for an office visit were contacted via phone and answered questions to obtain postoperative ASES and VAS scores.

CONCLUSION

Acromiohumeral cerclage suture augmentation in revision rTSA may be a useful, simple surgical strategy to employ with other revision and augmentation techniques to treat cases of recurrent, chronic instability, particularly in the setting of multiple revisions.

Instability after reverse total shoulder arthroplasty: risk factors and how to avoid them

Instability after RTSA (4’7%) remains a complication with limited salvage options... or not? We conducted a study of the incidence, predisposing factors, and treatment of RTSA instability to risk stratify patient and identify the most reliable treatment methods. We retrospectively searched for RTSAs performed between 2008 and 2017 at our institution by one surgeon using the same technique. We identified post- operative dislocations or symptoms of instability. 103 patients underwent 103 RTSAs (97 primary, 6 revision). 6 patients had 5 dislocations (3 in primary RTSAs, 3 in revision RTSAs). Mean time from surgery to diagnosis was 32.6 days (range, 10-60 days). One dislocation occurred immediately after surgery, 0 after falls, 3 from low-energy mechanisms of injury, and 2 without known inciting events. All dislocations were treated in the operating room; no dislocation was successfully treated with simple closed reduction in the clinic. Although dislocation after RTSA is uncommon, the risk is higher for patients with higher BMI and for patients undergoing revision surgery. The highest risk of instability occurs in RTSAs done for severe proximal humerus fracture; where the anatomy of the shoulder is changed. In these cases, approximately one in four patients will have a recurrent dislocation. In patients with persistent instability or with risk factors for instability, consideration should be given for use of larger glenospheres and increasing the lateral offset at the time of RTSA. Besides, peri- glenoid release, the suitable tension of the soft tissues tend to be the key of the stability.

Chronic Unreduced Anterior Shoulder Dislocation Managed by Latarjet Procedure: A Prospective Study

The shoulder joint is the most common joint to undergo dislocation, with the anterior subtype being the most common. The most accepted definition of chronic dislocation is a shoulder joint that has remained dislocated for a minimum of three weeks. Due to rare presentation, there is a lack of consensus among surgeons regarding the optimal management option of chronic shoulder dislocation. The goal of this prospective study was to assess the efficacy of open reduction with Latarjet procedure in the management of chronic unreduced shoulder dislocation. A total of seven patients were included in this study. Five patients were males and two were females. The study was conducted in a single tertiary care centre between July 2015 and May 2018. All patients were managed by open reduction with the Latarjet procedure. The capsulolabral structures were repaired in all the cases. The post-operative functional outcome was assessed by shoulder range, Rowe score, and the University of California, Los Angeles (UCLA) score at regular intervals for a period of one year. There was a significant improvement in terms of pain relief and functional status of the patients. The patients were satisfied as they could do their daily routine activities without pain at a one-year follow-up. Early post-operative rehabilitation and physiotherapy are key to improving the functional range.

Maximizing Muscle Function in Cuff-Deficient Shoulders: A Rehabilitation Proposal for Reverse Arthroplasty

Purpose

The purpose of this review is to describe the role of altered joint biomechanics in reverse shoulder arthroplasty and to propose a rehabilitation protocol for a cuff-deficient glenohumeral joint based on the current evidence.Methods and Materials: The proposed rehabilitation incorporates the principles of pertinent muscle loading while considering risk factors and surgical complications.

Results

In light of altered function of shoulder muscles in reverse arthroplasty, scapular plane abduction should be more often utilized as it better activates deltoid, teres minor, upper trapezius, and serratus anterior. Given the absence of supraspinatus and infraspinatus and reduction of external rotation moment arm of the deltoid in reverse arthroplasty, significant recovery of external rotation may not occur, although an intact teres minor may assist external rotation in the elevated position.

Conclusion

Improving the efficiency of deltoid function before and after reverse shoulder arthroplasty is a key factor in the rehabilitation of the cuff deficient shoulders. Performing exercises in scapular plane and higher abduction angles activates deltoid and other important muscles more efficiently and optimizes surgical outcomes.

Mechanical complications and fractures after reverse shoulder arthroplasty related to different design types and their rates: part I

The initial reverse shoulder arthroplasty (RSA), designed by Paul Grammont, was intended to treat rotator cuff tear arthropathy in elderly patients. In the early experience, high complication rates (up to 24%) and revision rates (up to 50%) were reported.The most common complications reported were scapular notching, whereas clinically more relevant complications such as instability and acromial fractures were less commonly described.Zumstein et al defined a 'complication' following RSA as any intraoperative or postoperative event that was likely to have a negative influence on the patient's final outcome.High rates of complications related to the Grammont RSA design led to development of non-Grammont designs, with 135 or 145 degrees of humeral inclination, multiple options for glenosphere size and eccentricity, improved baseplate fixation which facilitated glenoid-sided lateralization, and the option of humeral-sided lateralization.Improved implant characteristics combined with surgeon experience led to a dramatic fall in the majority of complications. However, we still lack a suitable solution for several complications, such as acromial stress fracture. Cite this article: EFORT Open Rev 2021;6:1097-1108. DOI: 10.1302/2058-5241.6.210039.

Reverse total shoulder arthroplasty for oncologic reconstruction of the proximal humerus: a systematic review

BACKGROUND

In recent years, there has been growing interest in the use of reverse total shoulder arthroplasty (rTSA) for reconstruction of the proximal humerus after oncologic resection. However, the indications and outcomes of oncologic rTSA remain unclear.

METHODS

We conducted a systematic review to identify studies that reported outcomes of patients who underwent rTSA for oncologic reconstruction of the proximal humerus. Extracted data included demographic characteristics, indications, operative techniques, outcomes, and complications. Weighted means were calculated according to sample size.

RESULTS

Twelve studies were included, containing 194 patients who underwent rTSA for oncologic reconstruction of the proximal humerus. The mean patient age was 48 years, and 52% of patients were male. Primary malignancies were present in 55% of patients; metastatic disease, 30%; and benign tumors, 9%. The mean humeral resection length was 12 cm. The mean postoperative Musculoskeletal Tumor Society score was 78%; Constant score, 60; and Toronto Extremity Salvage Score, 77%. The mean complication rate was 28%, with shoulder instability accounting for 63% of complications. Revisions were performed in 16% of patients, and the mean implant survival rate was 89% at a mean follow-up across studies of 53 months.

CONCLUSIONS

Although the existing literature is of poor study quality, with a high level of heterogeneity and risk of bias, rTSA appears to be a suitable option in appropriately selected patients undergoing oncologic resection and reconstruction of the proximal humerus. The most common complication is instability. Higher-quality evidence is needed to help guide decision making on appropriate implant utilization for patients undergoing oncologic resection of the proximal humerus.

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.

Outcome and complications following revision shoulder arthroplasty : a systematic review and meta-analysis

AIMS

It is important to understand the rate of complications associated with the increasing burden of revision shoulder arthroplasty. Currently, this has not been well quantified. This review aims to address that deficiency with a focus on complication and reoperation rates, shoulder outcome scores, and comparison of anatomical and reverse prostheses when used in revision surgery.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review was performed to identify clinical data for patients undergoing revision shoulder arthroplasty. Data were extracted from the literature and pooled for analysis. Complication and reoperation rates were analyzed using a meta-analysis of proportion, and continuous variables underwent comparative subgroup analysis.

RESULTS

A total of 112 studies (5,379 shoulders) were eligible for inclusion, although complete clinical data was not ubiquitous. Indications for revision included component loosening 20% (601/3,041), instability 19% (577/3,041), rotator cuff failure 17% (528/3,041), and infection 16% (490/3,041). Intraoperative complication and postoperative complication and reoperation rates were 8% (230/2,915), 22% (825/3,843), and 13% (584/3,843) respectively. Intraoperative and postoperative complications included iatrogenic humeral fractures (91/230, 40%) and instability (215/825, 26%). Revision to reverse total shoulder arthroplasty (TSA), rather than revision to anatomical TSA from any index prosthesis, resulted in lower complication rates and superior Constant scores, although there was no difference in American Shoulder and Elbow Surgeons scores.

CONCLUSION

Satisfactory improvement in patient-reported outcome measures are reported following revision shoulder arthroplasty; however, revision surgery is associated with high complication rates and better outcomes may be evident following revision to reverse TSA. Cite this article: Bone Jt Open 2021;2(8):618-630.

The relationship between glenoid inclination and instability following primary reverse shoulder arthroplasty

PURPOSE

Despite advances in implant design and surgical technique, instability remains the most common early complication and reason for early revision after reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the glenoid implant inclination, as measured by the β-angle, as an independent risk factor for instability after primary RSA.

METHODS

A retrospective case-control study was conducted matching cases with instability after primary RSA using a single implant to controls without instability. Controls were matched to age, sex, body mass index, and baseplate type (1:3 ratio of cases to controls). The preoperative, postoperative, and the change in pre- to postoperative glenoid inclination (β-angle) were compared between groups.

RESULTS

Thirty-four cases (mean age, 66.2 years) were matched to 102 controls (mean age, 67.0 years). There was a wide range of postoperative (63° to 100°) and pre- to postoperative change (-16.5° to +30.5°) in β-angles collectively. There was no significant difference in the postoperative β-angle (mean, 80.8° vs. 82.7°, P = .19) or the change in β-angle (mean, +1.7° vs. +3.4°, P = .35) between cases and controls, respectively. Regression analysis demonstrated no increased odds of instability with the postoperative β-angle, odds ratio 0.965 (confidence interval [CI] = 0.916-1.02, P = .19). Likewise, for the preoperative to postoperative change in β-angle, there was no significantly increased odds of instability, odds ratio 0.978 (CI = 0.934-1.03, P = .35). Finally, there was no difference in risk of instability in patients whose implant positioning resulted in a net superior increase in inclination, relative risk 0.85 (95% CI = 0.46-1.56, P = .28).

CONCLUSIONS

Neither the final prosthetic glenoid inclination nor the change in glenoid inclination, as measured by the β-angle, significantly influences the risk of prosthetic instability after primary RSA.

Incidence of peripheral nerve injury in revision total shoulder arthroplasty: an intraoperative nerve monitoring study

BACKGROUND

The incidence of nerve injuries in revision total shoulder arthroplasty (TSA) is not well defined in the literature and may be higher than that in primary procedures, with 1 study reporting a complication rate of 50% for shoulder revisions. Given that continuous intraoperative nerve monitoring (IONM) can be an effective tool in diagnosing evolving neurologic dysfunction and preventing postoperative injuries, the purpose of this study was to report on IONM data and nerve injury rates in a series of revision TSAs.

METHODS

A retrospective cohort review of consecutive patients who underwent revision TSA was performed from January 2016 to March 2020. Indications for revision included infection (n = 7); failed total arthroplasty and hemiarthroplasty secondary to pain, dysfunction, and/or loose components (n = 36); and periprosthetic fracture (n = 1). Of the shoulders, 32 underwent revision to a reverse TSA, 6 underwent revision to an anatomic TSA, and 6 underwent spacer placement. IONM data included transcranial electrical motor evoked potentials (MEPs), somatosensory evoked potentials, and free-run electromyography. The motor alert threshold was set at ≥80% signal attenuation in any peripheral nerve. Patients were screened for neurologic deficits immediately following surgery, prior to administration of an interscalene nerve block, and during the first 2 postoperative visits. Additional data collection included surgical indication, sex, laterality, age at surgery, procedure performed, body mass index, history of tobacco use, Charlson Comorbidity Index, medical history, and preoperative range of motion.

RESULTS

A total of 44 shoulders in 38 patients were included, with a mean age of 63.2 years (standard deviation, 13.0 years). Of the procedures, 22.4% (n = 10) had an MEP alert, with 8 isolated to a single nerve (7 axillary and 1 radial) and 1 isolated to the axillary and musculocutaneous nerves. Only 1 patient experienced a major brachial plexus alert involving axillary, musculocutaneous, radial, ulnar, and median nerve MEP alerts, as well as ulnar and median nerve somatosensory evoked potential alerts. Age, sex, body mass index, Charlson Comorbidity Index, and preoperative range of motion were not found to be significantly different between cases in which an MEP alert occurred and cases with no MEP alerts. In the postoperative period, no minor or major nerve injuries were found whereas distal peripheral neuropathy developed in 4 patients (9.1%).

CONCLUSION

Among 44 surgical procedures, no patients (0%) had a major or minor nerve injury postoperatively and 4 patients (9.1%) complained of distal peripheral neuropathy postoperatively. In this study, we have shown that through the use of IONM, the rate of minor and major nerve injuries can be minimized in revision shoulder arthroplasty.

Neurologic complications in primary anatomic and reverse total shoulder arthroplasty: A review

Neurologic injury during shoulder replacement is one of the less common complications of the procedure, however the clinical implications can be significant. The purpose of this paper is to review the current literature on neurologic complications in various types of shoulder replacement and provide recommendations regarding avoidance, evaluation, and management of these complications.

Anatomic factors influencing the anterior stability of reverse total shoulder arthroplasty

BACKGROUND

Several factors affect the stability of the reverse shoulder arthroplasty. The influence of bony anatomy on anterior stability remains unclear. This study aimed to identify the correlations between bony anatomy and anterior dislocation forces.

METHODS

The differences in anterior dislocation force in reverse total shoulder arthroplasty reported in a previous biomechanical study were used to analyze the anatomic factors influencing anterior stability. The critical shoulder angle, glenocoracoid distance in 2 planes, and glenoid inclination were measured in the tested specimens using 3-dimensional computed tomographic scans and radiographs. Anatomic parameters were then correlated with the anterior dislocation forces.

RESULTS

The critical shoulder angle had no correlation with anterior stability. The glenocoracoid distance in anteroposterior direction showed a negative correlation with the stability of a reverse shoulder arthroplasty with a 9-mm lateralized glenosphere and 155° humeral inclination in 30° and 60° glenohumeral abduction with the arm in 30° external rotation (r = -0.662, P = .004; r = -0.794, P = .011) and 30° glenohumeral abduction with neutral rotation (r = -0.614, P = .009). Using the same hardware configuration, the anterior stability had a negative correlation with the glenocoracoid distance in the mediolateral direction in 30° of glenohumeral abduction with the arm in 0° and 30° of external rotation (r = -0.542, P = .025; r = -0.497, P = .042).

CONCLUSION

The distance between the coracoid tip and glenoid in 2 planes had a significant negative correlation with the anterior stability of the reverse shoulder arthroplasty with a lateralized glenosphere and 155° humeral inclination. The findings suggest that only glenoid lateralization is influenced by the bony anatomy.

Polyethylene Liner Dissociation after Reverse Shoulder Arthroplasty Dislocation: a Case Series

Reverse shoulder arthroplasty is a common procedure. While dislocation is a common complication, there are few reports documenting dislocation with associated polyethylene liner dissociation from the humeral tray. There have been 4 instances of this occurrence over 9 years at our institution, and there are specific radiographic clues for diagnosis. Recognizing polyethylene liner dissociation on imaging is important prior to treatment. In a "routine" dislocation, closed reduction may be attempted but when the polyethylene is dissociated, open reduction is the only treatment option, as closed reduction can damage the components. Dislocations with polyethylene dissociation may not be initially recognized, prompting a non-operative period leading to wear and metallosis. These 4 cases demonstrate key findings present on imaging to recognize the difference between a dislocation with and without polyethylene liner dissociation, namely the subluxation appearance rather than dislocation.

Treatment of Chronic Anterior Shoulder Dislocation by Coracoid Osteotomy with or without Bristow-Latarjet Procedure

Objective

To investigate the clinical efficacy and outcomes of the coracoid osteotomy with or without Bristow–Latarjet procedures in the treatment of chronic anterior shoulder dislocation (CASD).

Methods

Between January 2013 and January 2019, 20 shoulders of 18 patients who were diagnosed with chronic anterior dislocation and underwent open reduction in our trauma center were retrospectively studied. Open coracoid osteotomy with Bristow–Latarjet procedures were performed on 16 shoulders and open coracoid osteotomy without Bristow–Latarjet procedures were performed on four shoulders. Open coracoid osteotomy with or without Bristow–Latarjet procedures were chosen on the basis of the stability of the shoulder after reduction. Outcomes were assessed preoperatively and postoperatively with the visual analog scale (VAS) for pain, the American Shoulder and Elbow Surgeons (ASES) score, the University of California Los Angeles (UCLA) shoulder rating scale, and the range of motion (ROM) for shoulder activity.

Results

There were three males and 15 females with an average age of 60.94 ± 2.69 years. The time between dislocation and treatment ranged from 21 to 240 days with an average of 73.3 ± 14.4 days. All patients were available for a mean follow‐up of 15.2 ± 4.3 months. No procedure‐related death or incision‐related superficial or deep tissue infection was identified in all cases. No iatrogenic neurovascular injuries or fractures were found in this study. At the time of 12 months follow‐up, the range of motion and the shoulder functional evaluation (VAS [P < 0.001], ASES [P < 0.001], and UCLA score [P < 0.001]) in patients who underwent Bristow–Latarjet procedures were significantly improved. Subluxation after surgical procedure was found and confirmed in one patient and this patient refused to undergo revision surgery. According to the Samilson and Prieto classification system, 16 shoulders were assessed as grade 0, three shoulders were grade 1, one shoulder was grade 2.

Conclusions

Coracoid osteotomy with or without Bristow–Latarjet procedure yielded an acceptable clinical result in this study. This method has the advantages of enlarging the exposure of surgical field, assisting reduction of shoulder, and convenient conversion to Bristow–Latarjet procedure. It is an efficient and reliable method for treatment of chronic anterior shoulder dislocation.

A 69‐year‐old woman diagnosed with right chronic anterior shoulder dislocation with large Hill–Sachs lesion. The latarjet procedure with remplissage technique was applied for this patient.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part II

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this study was to provide a focused, updated systematic review for each of the most common complications of RSA by limiting each search to publications after 2010. In this part II, the following were examined: (1) instability, (2) humerus/glenoid fracture, (3) acromial/scapular spine fractures (AF/SSF), and (4) problems/miscellaneous.

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Overall, 137 studies for instability, 94 for humerus/glenoid fracture, 120 for AF/SSF, and 74 for problems/miscellaneous were included in each review, respectively. Univariate analysis was performed with chi-square and Fisher exact tests.

Results

The Grammont design had a higher instability rate vs. all other designs combined (4.0%, 1.3%; P < .001), and the onlay humerus design had a lower rate than the lateralized glenoid design (0.9%, 2.0%; P = .02). The rate for intraoperative humerus fracture was 1.8%; intraoperative glenoid fracture, 0.3%; postoperative humerus fracture, 1.2%; and postoperative glenoid fracture, 0.1%. The rate of AF/SSF was 2.6% (371/14235). The rate for complex regional pain syndrome was 0.4%; deltoid injury, 0.1%; hematoma, 0.3%; and heterotopic ossification, 0.8%.

Conclusions

Focused systematic reviews of recent literature with a large volume of shoulders demonstrate that using non-Grammont modern prosthesis designs, complications including instability, intraoperative humerus and glenoid fractures, and hematoma are significantly reduced compared with previous studies. As the indications continue to expand for RSA, it is imperative to accurately track the rate and types of complications in order to justify its cost and increased indications.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part I

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this 2-part study was to systematically review each of the most common complications of RSA, limiting each search to publications in 2010 or later. In this part (part I), we examined (1) scapular notching (SN), (2) periprosthetic infection (PJI), (3) mechanical failure (glenoid or humeral component), and (4) neurologic injury (NI).

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Overall, 113 studies on SN, 62 on PJI, 34 on mechanical failure, and 48 on NI were included in our reviews. Univariate analysis was performed with the χ² or Fisher exact test.

Results

The Grammont design had a higher SN rate vs. all other designs combined (42.5% vs. 12.3%, P < .001). The onlay humeral design had a lower rate than the lateralized glenoid design (10.5% vs. 14.8%, P < .001). The PJI rate was 2.4% for primary RSA and 2.6% for revision RSA. The incidence of glenoid and humeral component loosening was 2.3% and 1.4%, respectively. The Grammont design had an increased NI rate vs. all other designs combined (0.9% vs. 0.1%, P = .04).

Conclusions

Focused systematic reviews of the recent literature with a large volume of RSAs demonstrate that with the use of non-Grammont modern prosthesis designs, complications including SN, PJI, glenoid component loosening, and NI are significantly reduced compared with previous studies. As the indications for RSA continue to expand, it is imperative to accurately track the rates and types of complications to justify its cost and increased indications.

Effectiveness of formal physical therapy following total shoulder arthroplasty: A systematic review

BACKGROUND

Physical therapy is considered routine practice following total shoulder arthroplasty. To date, current regimens are based on clinical opinion, with evidence-based recommendations. The aim of this systematic review was to evaluate the effectiveness of total shoulder arthroplasty physical therapy programmes with a view to inform current clinical practice, as well as to develop a platform upon which future research might be conducted.

METHODS

An electronic search of MEDLINE, EMBASE, CINAHL and Cochrane Library to March 2018 was complemented by hand and citation-searching. Studies were selected in relation to pre-defined criteria. A narrative synthesis was undertaken.

RESULTS

A total of 506 papers were identified in the electronic database search, with only one study showing moderate evidence of early physical therapy promoting a more rapid return of short-term improvement in function and pain. No studies evaluated the effectiveness of physical therapy programmes in reverse total shoulder arthroplasty procedures.

DISCUSSION

Restoring range of motion and strength following total shoulder arthroplasty is considered important for patients to obtain a good outcome post-surgery and, when applied early, may offer more rapid recovery. Given the rising incidence of total shoulder arthroplasties, especially reverse total shoulder arthroplasty, there is an urgent need for high-quality, adequately powered randomised controlled trials to determine the effectiveness of rehabilitation programmes following these surgeries.

Rehabilitation After Anatomic and Reverse Total Shoulder Arthroplasty: A Critical Analysis Review

Postoperative rehabilitation is believed to be essential in optimizing clinical outcome and function following shoulder arthroplasty. Despite this long-held notion, there is a paucity of high-quality evidence to guide rehabilitation protocols and practice. For patients undergoing anatomic total shoulder arthroplasty (ATSA), there are insufficient comparative data regarding type or duration of sling utilization. Based on current evidence, there is no appreciable benefit to early motion compared with a delayed-motion protocol following ATSA. There is insufficient literature to support the use of formal physical therapy over a physician-directed program following ATSA. At the present time, no high-quality evidence exists to guide the postoperative rehabilitation of patients undergoing reverse total shoulder arthroplasty (RTSA). Prospective randomized controlled trials evaluating postoperative management and rehabilitation following ATSA and RTSA are needed to guide best practices and optimize clinical outcomes.

A randomized single-blinded trial of early rehabilitation versus immobilization after reverse total shoulder arthroplasty

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) does not have a standard postoperative protocol. Although instability is a worrisome complication, prolonged immobilization may also be disabling in the elderly population. This study aimed to determine if early vs. delayed range of motion (ROM) after RTSA affected postoperative ROM, patient-reported outcomes, and the dislocation rate.

METHODS

A single-blinded, randomized controlled trial was performed enrolling patients from 2013 to 2017. Patients were randomly assigned to either a delayed-rehabilitation group (no ROM for 6 weeks) or early-rehabilitation group (immediate physical therapy for passive and active ROM) and followed up for a minimum of 1 year. Demographic characteristics, ROM, American Shoulder and Elbow Surgeons (ASES) scores, and complications were recorded.

RESULTS

Of an initial enrollment of 107 shoulders, 80.3% completed 1-year follow-up: 44 shoulders in the delayed-therapy group and 42 shoulders in the immediate-therapy group. Both groups had significantly improved forward flexion (32° improvement) and abduction (22° improvement) by 3 months. Both groups showed significant improvements in ASES scores by 6 weeks (9.4-point improvement in composite score) with continued improvement through 6 months (35.1 points). No significant differences were found between groups for any postoperative measure, with the exception of the ASES functional score favoring the delayed-therapy group at 6 months (26.3-point improvement vs. 16.7-point improvement). No differences in complications, notching, or narcotic use were noted between groups.

CONCLUSIONS

Both early- and delayed-ROM protocols after RTSA demonstrated significant, similar improvements in ROM and outcomes. Early initiation of postoperative rehabilitation may benefit the elderly population by avoiding the limitations of prolonged immobilization postoperatively.

Failed Reverse Shoulder Arthroplasty and Recommendations for Revision

PURPOSE OF REVIEW

The most common complications warranting revision consideration in reverse shoulder arthroplasty (RSA) include instability and its associated causes: infection, periprosthetic fracture, and glenoid baseplate loosening. Management of complications can be challenging and the nuances of treatment are still being elucidated. The focus of this paper is to review the treatment of the failed RSA and discuss evidence-based recommendations for revision.

RECENT FINDINGS

The most common complications requiring revision RSA are instability and infection. The causes for instability can be subdivided into three main subcategories: loss of compression, loss of containment, and impingement. Loss of compression is further broken down into 6 subcategories revolving around abnormal prosthesis positioning, undersized prostheses, or intrinsic soft-tissue tension loss leading to instability. Periprosthetic infection can also lead to instability, yet the most appropriate management for infected RSA remains controversial. Restoring stability by maximizing deltoid and soft tissue tension while avoiding impingement revolves around three basic methods: (1) lateralizing and/or upsizing the glenosphere to an inferior position on the glenoid, (2) use of a more constrained polyethylene insert, and (3) distalizing the humerus by increasing the polyethylene thickness and/or the thickness of the humeral tray. Management of periprosthetic joint infection can be performed in one-stage, two-stage, or "three-stage" procedures all showing good outcomes with two-stage procedures being the most commonly performed. However, persistent positive culture with propriobacterium acnes can occur in up to 25% of cases. In order to limit the associated morbidity from failed revision reverse shoulder arthroplasty, continued research on best management of associated complications is warranted.

Clinical outcomes and complications of reverse shoulder arthroplasty used for failed prior shoulder surgery: a systematic review and meta-analysis

Background

Reverse shoulder arthroplasty (RSA) is frequently performed in the revision setting as a salvage procedure. The purpose of this study was to report the clinical outcomes and complication, reoperation, and revision rates after revision RSA (RRSA) stratified according to the primary shoulder procedure undergoing revision.

Methods

Four databases (Embase, MEDLINE, SPORTDiscus, and Cochrane Controlled Trials Register) were searched for eligible studies published between January 1985 and September 2017. The primary outcomes of interest included pain, active range of motion, and functional outcome scores. Secondary outcomes included complication, reoperation, and revision rates.

Results

A total of 43 studies (1041 shoulder arthroplasties) met the inclusion criteria, with a mean follow-up period of 43.8 months (range, 31.1-57.2 months). Pain scores improved in all groups; however, none reached statistical significance. Range of motion improved in all groups, except for external rotation in the RSA category. RRSA demonstrated significant improvements in the Simple Shoulder Test score and Constant score (CS) in the group undergoing hemiarthroplasty (HA) for fracture, CS in the group undergoing HA for other indications, and CS in the group undergoing anatomic total shoulder arthroplasty. Pooled complication rates were highest in the failed RSA group (56.2%), followed by the group undergoing HA for other indications (27.7%), total shoulder arthroplasty group (23.6%), soft-tissue repair group (20.6%), open reduction and internal fixation group (19.0%), and group undergoing HA for fracture (13.6%).

Conclusions

Compared with other revision indications, RRSA for failed HA demonstrated the most favorable outcomes, whereas the highest complication and revision rates were observed in the RSA subgroup. This information is useful when establishing patient expectations regarding the risks, benefits, and complication and revision rates of RRSA.

Advances and Update on Reverse Total Shoulder Arthroplasty

PURPOSE OF REVIEW

Reverse total shoulder arthroplasty (RTSA) is a procedure that has been increasingly utilized since its inception over 20 years ago. The purpose of this review is to present the most up to date practice and advances to the RTSA literature from the last 5 years.

RECENT FINDINGS

Recent literature on RTSA has focused on identifying complications, maximizing outcomes, and determining its cost-effectiveness. RTSA has become a valuable tool in the treatment of various shoulder pathologies from fractures to massive-irreparable rotator cuff tears. Maximizing outcomes, proper patient counseling, and limiting complications are vital to a successful procedure. RTSA can be a difficult procedure; however, when utilized appropriately, it can be an invaluable tool in the orthopedic surgeon's armament. Recent evidence suggests, more and more, that RTSA not only provides value to the patient, but it is also cost-effective.

Body mass index as a risk factor for dislocation of total shoulder arthroplasty in the first 30 days

Background

Dislocation of total shoulder arthroplasty has an incidence as high as 31%. Obesity is one of many proposed risk factors, but no consensus exists on this relationship. The purpose of this study was to determine whether there is a relationship between body mass index (BMI) and dislocation of total shoulder arthroplasty.

Methods

The National Surgical Quality Improvement Program database was used to identify patients older than 50 years who underwent anatomic or reverse total shoulder arthroplasty between the years 2012 and 2016 for primary or secondary osteoarthritis, post-traumatic arthritis, or cuff tear arthropathy. Patients requiring reoperation or readmission for dislocation were identified by Current Procedural Terminology code. The relationship between World Health Organization BMI classification and dislocation was assessed.

Results

A total of 9382 patients were identified; 46% were male and 54% female, with an average age of 68.7 years (range 50-90) and average BMI of 31.2 (range 15.1-79.3). There were only 24 dislocation events within the first 30 days after the procedure (0.26%). Ten of 24 (42%) occurred after discharge. Seventy percent of cases (17 of 24) required an open procedure. Underweight patients (BMI < 18.5) experienced the highest dislocation rate (1/50, 2.00%), whereas overweight patients (BMI 25-29.9) experienced the lowest dislocation rate (3/3069, 0.1%).

Conclusion

The rate of dislocation of total shoulder arthroplasty in the acute postoperative period differs across categories of BMI. However, there does not appear to be a linear association between BMI and risk of dislocation of total shoulder arthroplasty. Further studies are required to elucidate the risk factors for total shoulder dislocation.

[Primary fracture protheses and reverse shoulder arthroplasty in complex humeral head fractures : An alternative to joint-preserving osteosynthesis?]

BACKGROUND

The surgical management of complex humeral head fractures has adapted dynamically over the course of the last decade. The primary use of reverse shoulder arthroplasty in elderly patients has gained in relevance due to promising short and middle-term results. Long-term results, however, are still pending. The appliance of anatomical hemiarthroplasty, on the other hand, has lost in significance in favour of osteosynthesis and reverse shoulder arthroplasty.

INDICATIONS

This review article follows the question as to under which circumstances primary fracture arthroplasty reflects an alternative or even a preference to joint-preserving osteosynthesis in the treatment of complex proximal humeral fractures. It also specifies spectrums of indications for anatomical hemiarthroplasty and reverse shoulder arthroplasty.

Revision Reverse Shoulder Arthroplasty

As shoulder arthroplasty becomes increasingly common, the burden of revision shoulder arthroplasty is also increasing. Revision reverse shoulder arthroplasty requires an understanding of the causes of failure and the evaluation of these causes and their sequelae, including infection, instability, component loosening, humeral bone loss, and glenoid bone loss. Revision reverse shoulder arthroplasty is technically complex. On the humeral side, corticotomy may be required for component removal, and bone grafting may be necessary to achieve rotational stability and to restore humeral length and avoid undertensioning and instability. On the glenoid side, bone loss is common, structural bone grafting is not infrequently required, and proper component positioning is required to avoid impingement and component loosening. Although the outcomes are generally inferior to primary reverse total shoulder arthroplasty and complications and revision surgeries are common, revision procedures still lead to notable improvements in pain, motion, and function.

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

Background

Indications for reverse total shoulder arthroplasty (RTSA) have expanded. The purpose of this retrospective cohort study was to evaluate national trends in shoulder arthroplasty utilization and to compare national perioperative complication rates for hemiarthroplasty (HA), total shoulder arthroplasty (TSA), and RTSA in a matched cohort.

Methods

The National Inpatient Sample was queried from 2011-2013 to identify patients who underwent HA, TSA, or RTSA. Age, sex, race, insurance type, Elixhauser comorbidity index, and perioperative complications were identified. A coarsened exact matching algorithm was used to match RTSA patients with TSA and HA patients to compare medical and implant-related perioperative in-hospital complications. Multivariable logistic regression analysis was performed on unmatched data to identify risk factors for development of perioperative complications.

Results

Overall, 42,832 shoulder arthroplasties were identified (44% TSAs, 34% RTSAs, 19% HAs). After matching, RTSAs had 6.2 times the odds of a perioperative implant-related complication (P < .001) and 2 times the odds of a red blood cell transfusion compared with TSAs (P < .001). The logistic regression model showed that prior shoulder arthroplasty (odds ratio [OR], 15.1; P < .001), younger age (OR, 0.98; P = .006), earlier year of index surgery (OR, 0.83; P = .002), history of illicit drug use (OR, 6.2; P = .008), and depression (OR, 2.3; P = .003) were risk factors for development of in-hospital implant-related complications after RTSA.

Conclusion

The perioperative implant-related complication rate and postoperative transfusion rate of RTSAs were significantly higher than those of TSAs. In addition, prior shoulder surgery, younger age, earlier year of index surgery, history of illicit drug use, and depression were risk factors for implant-related complications after RTSA. However, the perioperative RTSA implant-related complications did decline each year, suggesting a growing national proficiency with performing RTSA.

Incidence of clinically evident isolated axillary nerve injury in 869 primary anatomic and reverse total shoulder arthroplasties without routine identification of the axillary nerve

Background

It has been suggested that, during primary shoulder arthroplasty, surgeons should identify the axillary nerve through direct visualization, palpation, or the “tug test” to prevent iatrogenic nerve injury. Our goal was to document the rate of isolated axillary nerve injury (IANI) in patients who had undergone primary anatomic total shoulder arthroplasty (TSA) or reverse total shoulder arthroplasty (RTSA) without routine identification of the axillary nerve.

Methods

Data on 869 cases of primary shoulder arthroplasty (338 TSAs and 531 RTSAs) performed by 1 surgeon between 2003 and 2017 were reviewed. Neither the tug test nor identification of the axillary nerve through palpation or visualization was used in any case. The primary outcome was new IANI documented within 3 months after arthroplasty. The frequency of IANI was summarized using point estimates and 95% confidence intervals (CIs).

Results

Six cases met the criteria for IANI. The overall incidence of IANI was 0.7% (95% CI, 0.3%-1.4%). The incidence of IANI was 0.3% (95% CI, 0%-1.6%) after TSA and 0.9% (95% CI, 0.3%-2.1%) after RTSA. All IANIs were cases of neurapraxia, and all patients had experienced complete neurologic recovery at last follow-up.

Conclusion

Complete, permanent IANI resulting from direct surgical trauma during primary shoulder arthroplasty can be avoided without using the tug test or routine identification of the nerve. A low incidence of partial temporary IANI can be expected, which may be related to indirect traction injuries.

Subscapularis in Reverse Total Shoulder Arthroplasty

The use of reverse total shoulder arthroplasty (RSA) is becoming increasingly popular, but many biomechanical aspects are poorly understood. Particularly, the role and function of the subscapularis following RSA are unclear. Several clinical and biomechanical studies have analyzed its role in range of motion and stability. There is some evidence that the subscapularis is beneficial for stability but may reduce range of motion. This review provides an overview of the current literature, which suggests that the subscapularis may have a more important role in RSA than originally thought.

Clinical effectiveness and safety of the extended humeral head arthroplasty for selected patients with rotator cuff tear arthropathy

BACKGROUND

Cuff tear arthropathy is commonly managed with a reverse total shoulder arthroplasty (RTSA). A humeral hemiarthroplasty with an extended humeral head may provide a less invasive alternative for selected patients with cuff tear arthropathy if the shoulder has preserved active elevation. Because evidence regarding this procedure is limited, we investigated its safety and efficacy in treating selected patients with cuff tear arthropathy.

METHODS

We analyzed the preoperative characteristics, surgical findings, and clinical outcomes for patients selected for extended head hemiarthroplasty.

RESULTS

For 42 patients with 2-year follow-up, there were no complications or revisions. The Simple Shoulder Test score improved from a median of 3.0 to 8.0 (P < .001). The median percentage of maximal possible improvement was 50% (P < .001). The percentage of patients able to perform each of the functions of the Simple Shoulder Test was significantly improved; for example, the ability to sleep comfortably increased from 19% to 71%, and the ability to place a coin on the shelf at shoulder level increased from 38% to 86% (P < .001).

CONCLUSIONS

There are circumstances in which RTSA is clearly the preferred procedure for cuff tear arthropathy, including pseudoparalysis, anterosuperior escape, and glenohumeral instability; however, in shoulders with preserved active motion and stability of the humeral head provided by an intact coracoacromial arch, the extended head humeral arthroplasty can enable selected patients to realize improved comfort and function without the potential risks of RTSA. Extended humeral head hemiarthroplasty can provide a safe and effective alternative for the management of selected patients with rotator cuff tear arthropathy and preserved active motion.

The stabilization effect of the conjoint tendon in reverse total shoulder arthroplasty

BACKGROUND

Numerous factors determine stability of reverse total shoulder arthroplasty. The effect of the conjoint tendon in relation to stability remains unknown. In this biomechanical study, we evaluated the influence of the conjoint tendon on the anterior stability of reverse total shoulder arthroplasty with a hemispherical glenosphere and a glenosphere with 9 mm lateralisation.

METHODS

A reverse total shoulder arthroplasty was implanted in 6 human cadaveric shoulders. The anterior stability was evaluated using a shoulder simulator. Two conditions, intact and dissected conjoint tendon, and 2 component configurations, a hemispherical glenosphere and a glenosphere with 9 mm lateralisation, were tested in each specimen. Testing of anterior stability was performed in 30° and 60° of abduction, with 0° and 30° of external rotation in the glenohumeral joint.

FINDINGS

The conjoint tendon showed a significant influence on the anterior stability with a hemispherical glenosphere in 30° and 60° with neutral rotation (p = 0.028) as well as 30° abduction with 30° (p = 0.028) external rotation. The 9 mm lateralised glenosphere stabilized significantly reverse total shoulder arthroplasty with resected conjoint tendon compared to the hemispherical glenosphere with resected conjoint tendon (p = 0.028).

INTERPRETATION

In a biomechanical setting the conjoint tendon has a stabilizing influence on the anterior stability of the reverse total shoulder arthroplasty with a hemispherical glenosphere in an abducted arm position, but this stabilizing effect was not seen with the lateralised glenosphere. The single influence of the lateralisation of the glenosphere on anterior stability was shown in cases of resected conjoint tendon.

Management of the Failed Arthroplasty for Proximal Humerus Fracture

A variety of reasons exist for failure of arthroplasty performed for management of proximal humerus fracture. Revision surgery for these failures is complex and has a high likelihood of inferior outcomes compared with primary arthroplasty. Successful management requires consideration of various modes of failure including tuberosity malunion or resorption, rotator cuff deficiency, glenoid arthritis, bone loss, component loosening, stiffness, or infection. Although revision to a reverse shoulder arthroplasty is an appealing option to address instability, rotator cuff dysfunction, and glenoid arthritis, there are concerns with higher complication rates and inferior results compared with primary reverse replacement. Any treatment plan should appropriately address the cause for failure to optimize outcomes.