Instability in Reverse Total Shoulder Arthroplasty

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.

[Reverse Shoulder Arthroplasty - Current Concepts]

Due to first promising long term outcome data, reverse shoulder arthroplasty experienced an immense increase of usage during the past decade. Moreover, the initial Grammont concept has constantly been refined and adapted to current scientific findings. Therefore, clinical and radiological problems like scapular notching and postoperative instability were constantly addressed but do still remain an area of concern.This article summarises current concepts in reverse shoulder arthroplasty and gives an overview of actual indications like cuff tear arthropathy, severe osteoarthritis, proximal humerus fractures, tumours, fracture sequelae as well as revision surgery and their corresponding clinical and radiological results.

Orthopedic meta-implants

Meta-biomaterials, engineered materials with distinctive combinations of mechanical, physical, and biological properties stemming from their micro-architecture, have emerged as a promising domain within biomedical engineering. Correspondingly, meta-implants, which serve as the device counterparts of meta-biomaterials, offer exceptional functionalities, holding great potential for addressing complex skeletal diseases. This paper presents a comprehensive overview of the various types of meta-implants, including hybrid, shape-morphing, metallic clay, and deployable meta-implants, highlighting their unprecedented properties and recent achievement in the field. This paper also delves into the potential future developments of meta-implants, addressing the exploration of multi-functionalities in meta-biomaterials and their applications in diverse biomedical fields.

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.

Stemless Reverse Shoulder Arthroplasty

Since the Food and Drug Administration (FDA) approval nearly two decades ago, the indications for and utilization of reverse shoulder arthroplasty (RSA) have expanded considerably. Stemless RSA designs have been used in Europe since 2005, but have only recently been introduced in domestic Investigational Device Exemption trials. Potential advantages of stemless RSA are similar to those of stemless anatomic total shoulder arthroplasty, which may include fewer shaft-related complications, avoidance of stress shielding, bone preservation, and easier revision surgery. European data support similar outcomes between certain stemless RSA prostheses compared with that of stemmed RSA implants at early and mid-term follow-up. However, long-term outcomes remain to be seen and differences exist between the stemless RSA designs used in Europe and those being studied in domestic clinical trials. An understanding of the potential advantages and disadvantages of stemless RSA, differences between existing designs, and reported clinical outcomes is prudent for the safe and meaningful implementation of this new technology in the United States.

Custom-made Glenoid Baseplate and Intra-Operative Navigation in Complex Revision Reverse Shoulder Arthroplasty: A Case Report

Prosthetic instability is one of the most challenging complications to manage when considering reverse shoulder arthroplasty (RSA). Additional tools are available to improve accuracy in planning and execution of arthroplasties, such as 3-dimensional (3D) virtual planning based on computer tomography (CT) scan and intra-operative navigation. We report a case of an 84-year-old male treated for RSA prosthetic instability combined with severe glenoid deformity and bone loss, and subclinical periprosthetic joint infection (PJI). The definitive surgery consisted in implanting a customized metaglene component realized on the basis of the bone defect detected in the 3D-CT scan and implanted with the aid of computer-assisted intra-operative navigation. The patient was periodically followed-up for a year with clinical and radiological evaluations with the absence of further prosthetic dislocations nor PJI, a good overall satisfaction, a satisfying range of motion, and acceptable functional scores (American Shoulder and Elbow Surgeons Score 62, Constant-Murley Score 36). This is the first description, to our knowledge, of a customized glenoid baseplate implanted with the aid of intraoperative navigation. The combined use of 3D-CT planning and intra-operative computer-assisted navigation allows to manage complex cases of prosthetic revision surgery even where extensive bone defects are present.

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.

Effect of osteophyte removal on simulated range of motion using 3-dimensional preoperative planning software for reverse total shoulder arthroplasty

Background

Glenohumeral osteophytes (OPs) can adversely influence postoperative range of motion (ROM) following shoulder arthroplasty due to mechanical impingement. Though commercial three-dimensional preoperative planning software (3D PPS) is available to simulate ROM before and after OP resection, little is known about the magnitude of effect OPs and their subsequent removal have on simulated glenohumeral ROM.

Methods

Included patients were 1) indicated for reverse total shoulder arthroplasty (rTSA) using 3D PPS and 2) presented with glenoid and/or humeral head OPs on preoperative two-dimensional computed tomography (2D-CT) imaging. Thirty patients met the inclusion criteria (9 females, 21 males; mean age 70.45 ± 4.99 years, range 63-80 years). All subjects (n = 30) presented with humeral OPs (mean volume: 2905.16 mm3, range 109.1-11,246 mm3), while 11 subjects also presented with glenoid OPs (mean volume 108.06 mm3, range 37.59-791.4 mm3). Preoperative CTs were used to calculate OP volume (mm3) and OP circumferential extent (clockface). Mean clockface position for circumferential humeral OPs originated at 6:09 (range 4:30-7:15) and extended to 8:51 (range 8:15-10:15). Mean clockface position for glenoid OPs originated at 3:00 (range 2:00-5:00) and extended to 6:16 (range 3:00-7:30). 3D implants on PPS were standardized to achieve 0° of version, 0° of inclination and 4 mm of net lateralization. Thirty-nine and thirty-six mm glenospheres were used for males and females, respectively. 3D PPS was used to evaluate simulated ROM differences before and after OP removal in the planes of adduction (ADD), abduction, internal rotation (IR), external rotation (ER), extension, and flexion. Impact of OP volume and circumferential extent on pre and postop removal ROM were also analyzed.

Results

Humeral OP removal significantly increased impingement-free ADD, IR, ER, extension, and flexion. Removal of larger (mm3) humeral OPs positively correlated with improvement in IR (R = 0.452, P = .011), ER (R = 0.394, P = .033), and flexion (R = 0.500, P < .01). Greater circumferential extent of humeral OPs correlated with worse preremoval ROM in the planes of ADD (R = 0.364, P = .02) and extension (R = 0.403, P = .04), and improvements in ER postop removal (R = 0.431, P = .03).

Conclusion

Humeral OP removal significantly increases impingement-free ADD, IR, ER, extension, and flexion in simulated 3D PPS models following rTSA. Magnitude of simulated ROM improvement is influenced by initial humeral OP volume and circumferential clockface extent. Surgeons should consider these effects when using 3D PPS for rTSA planning to optimize postoperative ROM prognostics.

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.

Improved functional, radiographic and patient-reported outcomes at midterm follow-up for shoulder arthroplasty patients 75 years and older

Background

Current discussion centers around the appropriateness of shoulder arthroplasty in elderly patients, and whether anatomic and reverse total shoulder arthroplasty yield acceptable results in this population. The purpose of this study was to examine midterm outcomes in patients 75 years and older who underwent either procedure.

Methods

A retrospective review was performed on patients who underwent anatomic total shoulder arthroplasty (aTSA) or reverse total shoulder arthroplasty (rTSA) between 2000 and 2018. Inclusion criteria was patient age ≥75 years at time of surgery and ≥1 years postoperative follow-up. Primary outcomes were differences in Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) score, Visual Analog Scale (VAS) pain score, and range of motion. A secondary outcome was revision surgery.

Results

22 patients who underwent aTSA and 17 patients who underwent rTSA were included. Mean age at surgery was 79 and 80 in the aTSA and rTSA groups, respectively. Mean postoperative follow-up was 6.6 years across both cohorts. Anatomic TSA patients experienced improvements in VAS (7 preop vs. 1 postop; p < 0.001), ASES (16 vs. 75; p < 0.001), and SST (2 vs. 8; p < 0.001) scores. Reverse TSA patients also experienced improvements in VAS (7 vs. 1; p < 0.001), ASES (29 vs. 74; p < 0.001), and SST (1 vs. 7; p < 0.001) scores. Anatomic TSA patients experienced improved external rotation (17° vs. 53°; p < 0.001), forward elevation (108° vs. 155°; p < 0.001), and internal rotation (L5 vs. T10; p < 0.001). Reverse TSA patients experienced improved forward elevation (52° vs. 126°; p < 0.001). 21 aTSA patients (100%) and 16 rTSA patients (94%) experienced survival free from revision. 100% of aTSA and rTSA patients experienced survival free from loosening.

Conclusion

Both aTSA and rTSA can be performed in the elderly population with acceptable midterm outcomes, suggesting that implant survival and patient satisfaction have the potential to endure through the end of life.

Level of evidence

IV.

Long-Term Results of Primary Reverse Shoulder Arthroplasty for Massive, Irreparable Rotator Cuff Tears Without Glenohumeral Arthritis with a Mean Follow up of 9.4 Years

Background

The aim of this single-center study was to analyze the long-term clinical results of reverse shoulder arthroplasty in patients with massive, irreparable rotator cuff tears without glenohumeral arthritis.

Methods

A retrospective cohort study of 105 patients (115 shoulders) was conducted. The mean age of the patient group was 76 years (range, 65 to 87 years). The mean clinical follow-up was 9.4 years (range, 5 to 17 years). Pain, range of motion, and complication rates were analyzed pre-operatively and at the last follow-up.

Results

The mean Constant-Murley score increased from 29 points (range, 21 to 34 points) preoperatively to 68.1 points (range, 57 to 81 points) postoperatively (p<0.05). Scapular notching was present in 50 shoulders (43.5%) and it was grade 1 or 2 in 47 of 115 cases (40.9%) and grade 3 or 4 in 3 of 115 cases (2.6%). Complications occurred in 19 patients (17%). Seven patients (6%) underwent revision surgery. The mean satisfaction rate was 94%.

Conclusions

Reverse shoulder arthroplasty is a viable treatment for massive, irreparable rotator cuff tears without glenohumeral arthritis with satisfactory clinical outcomes and low complication and reoperation rates with a mean follow up of 9.4 years after surgery.

The Value of Computer-Assisted Navigation for Glenoid Baseplate Implantation in Reverse Shoulder Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Glenoid baseplate malpositioning during reverse total shoulder arthroplasty can contribute to perimeter impingement, dislocation, and loosening. Despite advances in preoperative planning, conventional instrumentation may lead to considerable inaccuracy in implant positioning unless patient-specific guides are used. Optical navigation has the potential to improve accuracy and precision when implanting a reverse shoulder arthroplasty baseplate. This systematic review aimed to analyze the most recent evidence on the accuracy and precision of glenoid baseplate positioning using intraoperative navigation and its potential impact on component selection and surgical time.

METHODS

We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The PubMed, Scopus, and EMBASE databases were queried in July 2022 to identify all studies that compared navigation vs. conventional instrumentation for reverse shoulder arthroplasty. Data of deviation from the planned baseplate version and inclination, the use of standard or augmented glenoid components, and surgical time were extracted. Quantitative analysis from the included publications was performed using the inverse-variance approach and Mantel-Haenszel method.

RESULTS

Of the 2,048 records identified in the initial query, only 10 articles met the inclusion and exclusion criteria, comprising 667 shoulders that underwent reverse total shoulder arthroplasty. The pooled mean difference (MD) of the deviation from the planned baseplate position for the clinical studies was -0.44 (95% confidence interval [CI], -3.26; p = 0.76; I2 = 36%) for version and -8.75 (95% CI, -16.83 to -0.68; p = 0.02; I2 = 83%) for inclination, both in favor of navigation. The odds ratio of selecting an augmented glenoid component after preoperative planning and navigation-assisted surgery was 8.09 (95% CI, 3.82-17.14; p < 0.00001; I2 = 60%). The average surgical time was 12 minutes longer in the navigation group (MD 12.46, 95% CI, 5.20-19.72; p = 0.0008; I2 = 71%).

CONCLUSIONS

Preoperative planning integrated with computer-assisted navigation surgery seems to increase the accuracy and precision of glenoid baseplate inclination compared with the preoperatively planned placement during reverse total shoulder arthroplasty. The surgical time and proportion of augmented glenoid components significantly increase when using navigation. However, the clinical impact of these findings on improving prosthesis longevity, complications, and patient functional outcomes is still unknown.

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis. See Instructions for Authors for a complete description of levels of evidence.

Evaluation of the Painful Total Shoulder Arthroplasty

Despite the overall success of anatomic and reverse total shoulder arthroplasties (aTSA and rTSA), some patients continue to have or develop pain postoperatively. As the number of shoulder arthroplasties continues to increase in the United States, it is important that surgeons are able to recognize, diagnose, and treat the various pathologies. Some painful etiologies are specific to either aTSA or rTSA, and others can occur with both implant types. Infections, stiffness, neurologic syndromes, polyethylene wear, aseptic implant loosening, and metal allergies occur, regardless of implant choice. However, after an aTSA, subscapularis repair failure, superior rotator cuff tear, and joint overstuffing can result in shoulder pain. After a rTSA, specific causes of postoperative pain include instability, scapular notching, acromial or scapular spine fractures, subcoracoid pain, and neurologic injury. Regardless of the diagnosis, the surgeon must be methodical in the evaluation and, when appropriate, use blood work, advanced imaging studies, joint aspirations, shoulder arthroscopy, and nerve studies. Once diagnosed, appropriate treatment should be undertaken to resolve the cause of the pain or at least minimize the effect of the pain on the patient's outcome.

What is the middle term survival of reverse shoulder arthroplasty? A retrospective observational registry-based study

PURPOSE

The use of reverse total shoulder arthroplasty has increased over the last decade. Like any other implant it is associated with complications sometimes leading to revision. We carried out a registry-based study in order to find possible risk factors associated with the need of revision surgery.

METHODS

The RIPO registry was analyzed from July 2008 to December 2018 collecting available data. Two groups (degenerative or fracture) were formed and compared to determine possible risk factors difference in revision surgery.

RESULTS

A total of 7,966 shoulder prosthesis were implanted. There was a 1.5% intra or peri-operative complication rate. The revision rate was 4.0% at a mean follow-up of 4.4 years. A total of 3,073 reverse total shoulder prosthesis were implanted and available for follow-up. An increase of revision rate (the most frequent causes being aseptic loosening, infection and instability) was found in patients younger than 65 years and in male patients. Two groups were then formed on the basis of the primary diagnosis: osteoarthritis and proximal humerus fracture. Comparison between the two groups showed an increase in instability requiring revision in the fracture group.

CONCLUSION

Reverse shoulder prosthesis is a valid treatment option both in the elective and in the trauma settings, but young and male patients should be informed of the inherently increased risk of revision and prosthesis used in the fracture setting should be evaluated more thoroughly to prevent instability.

Routine immediate postoperative radiographs rarely identify unknown complications after shoulder arthroplasty

BACKGROUND

Intraoperative complications after shoulder arthroplasty (SA) are uncommon, yet surgeons continue to obtain immediate postoperative radiographs despite prior literature questioning the efficacy of these images. There is a paucity of literature describing the role of immediate postoperative radiographs in revision SA. This study aimed to evaluate the utility of immediate postoperative radiographs in identifying intraoperative complications leading to a change in care after primary or revision SA. We hypothesized that routine postoperative ("survey") radiographs would not provide a high diagnostic yield in identifying early complications requiring a change in postoperative management.

METHODS

A retrospective review of 4063 SAs (1298 primary anatomic total shoulder arthroplasties [aTSAs], 2162 primary reverse shoulder arthroplasties [RSAs], 129 revision aTSAs, and 474 revision RSAs) was performed from a multi-institutional arthroplasty database. All shoulders were evaluated with a single immediate postoperative (survey) radiograph that was read by a musculoskeletal radiologist and by the treating orthopedic surgery team. The radiology reports of all 4063 immediate postoperative radiographs were reviewed to determine whether complications had been identified. For patients in whom complications were identified, the medical record was then reviewed to determine whether the survey radiograph resulted in a return to the operating room or a change in management between the surgical procedure and the first postoperative clinic visit with radiographic evaluation.

RESULTS

Complications were reported by a radiologist on the basis of immediate postoperative radiographs in 10 of 4063 shoulders (0.2%, or 1 of every 500 arthroplasties). Complications were reported after 4 primary RSAs, 4 revision aTSAs, and 2 revision RSAs; no complication was reported after any of the primary aTSAs. Of the 10 complications, only 3 were unknown to the treating surgeon following the operation and none altered immediate postoperative management. Early complications were reported at a rate of 1% after revision arthroplasty vs. 0.1% after primary arthroplasty (P = .001). Additionally, revision aTSA was found to have a higher rate of complications reported on radiographs, with a rate of 3.1%, compared with revision RSA, at 0.4% (P = .021).

CONCLUSION

The radiology reports of routine immediate postoperative radiographs rarely identified postoperative complications (0.2%). In all cases, postoperative management remained unaltered until the time of the first postoperative visit. The value and medicolegal implications of immediate postoperative radiographs may inform the decision to abandon obtaining these studies routinely.

Difference analysis of the glenoid centerline between 3D preoperative planning and 3D printed prosthesis manipulation in total shoulder arthroplasty

INTRODUCTION

Excessive version and inclination of the glenoid component during total shoulder arthroplasty can lead to glenohumeral instability, early loosening, and even failure. The orientation and position of the central pin determine the version and inclination of the glenoid component. The purpose of this study was to compare the differences in centerline position and orientation obtained using "3D preoperative planning based on the best-fit method for glenoid elements" and the surgeon's manipulation.

MATERIALS AND METHODS

Twenty-nine CT images of glenohumeral osteoarthritis of the shoulder were reconstructed into a 3D model, and a 3D printer was used to create an in vitro model for the surgeon to drill the center pin. The 3D shoulder model was also used for 3D preoperative planning (3DPP) using the best-fit method for glenoid elements. The in vitro model was scanned and the version, inclination and center position were measured to compare with the 3DPP results.

RESULTS

The respective mean inclinations (versions) of the surgeon and 3DPP were -2.63° ± 6.60 (2.87° ± 5.97) and -1.96° ± 4.24 (-3.21° ± 4.00), respectively. There was no significant difference in the inclination and version of the surgeon and 3DPP. For surgeons, the probability of the inclination and version being greater than 10° was 13.8% (4/29) and 10.3% (3/29), respectively. Compared to the 3DPP results, the surgeon's center position was shifted down an average of 1.63 mm. There was a significant difference in the center position of the surgeon and 3DPP (p < 0.05).

CONCLUSION

The central pin drilled by surgeons using general instruments was significantly lower than those defined using 3D preoperative planning and standard central definitions. 3D preoperative planning prevents the version and inclination of the centerline from exceeding safe values (± 10°).

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.].

Advances in Biomaterial-Mediated Gene Therapy for Articular Cartilage Repair

Articular cartilage defects caused by various reasons are relatively common in clinical practice, but the lack of efficient therapeutic methods remains a substantial challenge due to limitations in the chondrocytes’ repair abilities. In the search for scientific cartilage repair methods, gene therapy appears to be more effective and promising, especially with acellular biomaterial-assisted procedures. Biomaterial-mediated gene therapy has mainly been divided into non-viral vector and viral vector strategies, where the controlled delivery of gene vectors is contained using biocompatible materials. This review will introduce the common clinical methods of cartilage repair used, the strategies of gene therapy for cartilage injuries, and the latest progress.

Outcomes of instability after reverse shoulder arthroplasty: reoperation and persistent instability are common

HYPOTHESIS

Although risk factors for instability after reverse shoulder arthroplasty (RSA) have been extensively studied, the outcomes of patients who experience instability are unknown. The purpose of this study was to evaluate functional outcomes in patients with instability after RSA.

METHODS

We retrospectively identified patients with instability after RSA with a minimum of 2 years' follow-up from an institutional database. Baseline data were recorded, and all patients we contacted to obtain clinical outcome scores. Patients who required revision surgery and those treated successfully with closed reduction were compared.

RESULTS

Fifty patients were included. Of these patients, 40 (80%) required revision surgery whereas 10 (20%) were treated successfully with closed reduction. At an average follow-up of 63.7 months (range, 24-123 months), outcome scores did not differ between groups. Patients who required revision surgery were more likely to have undergone previous shoulder surgery, prior to their index arthroplasty (P = .031). Seventeen patients (42.5%) reported recurrent instability following revision surgery, and 14 (35.0%) required additional revision surgery. Ultimately, stability was never achieved in 7 of 50 patients (14%) after their index instability event.

CONCLUSION

Although instability after RSA can commonly be corrected with reasonable functional results, multiple procedures may be needed and some patients may experience persistent instability.

No Difference in Range of Motion in Reverse Total Shoulder Arthroplasty Using Standard or Constrained Liners: A Matched Cohort Study

Background

Prosthetic instability is one of the most common short-term complications following reverse total shoulder arthroplasty (RTSA). Numerous strategies exist to attempt to mitigate this complication, including utilization of constrained polyethylene humeral liners. A concern of constrained humeral liners is that they may come at the expense of restricted rotational range of motion (ROM). The purpose of the present study is to compare range of ROM and patient-reported outcomes (PROs), and satisfaction among matched cohorts using constrained vs. unconstrained liners after RTSA.

Methods

A multicenter shoulder arthroplasty registry was retrospectively reviewed to identify patients with two-year clinical follow-up after RTSA with constrained liners used at the surgeon’s discretion. All patients had the same inlay humeral prosthesis with a 135° neck shaft angle. This study cohort was matched 1:2 to control patients who underwent RTSA with standard liners based on age, sex, total glenoid-sided lateralization, glenosphere diameter, and surgery performed on the dominant arm. Improvement in PROs and ROM was compared between groups.

Results

Twenty-two patients were identified who underwent RTSA with a constrained humeral liner; these were compared to 44 matched patients with standard liners. The groups were found to have no notable differences in demographics, baseline PROs and ROM. At two years postoperatively, both cohorts demonstrated improvements in all PROs without statistically significant differences between the two groups. There were no differences between groups in improvement in any ROM measure, including forward flexion (constrained: 54^°, standard: 57^°, P = .771), external rotation at the side (constrained: 42°, standard: 41°, P = .906) or internal rotation at 90^° of abduction (constrained: 24^°, standard: 20^°, P = .587).

Conclusions

For an inlay humeral prosthesis with a 135^° neck shaft angle, utilization of a constrained liner for RTSA demonstrates no significant difference in ROM or PROs compared to a well-matched cohort of patients who underwent RTSA with a standard polyethylene humeral liner. These are reassuring data for using constrained liners when there is intraoperative concern for prosthetic instability.

Systematic review of prevalence, risk factors, and management of instability following reverse shoulder arthroplasty

Background

Since its approval for use, reverse shoulder arthroplasty (RSA) has become the primary treatment for cuff tear arthropathy, with indications expanding more recently to include revision fracture, osteoarthritis with significant glenoid bone loss, tumor, and chronic instability. Instability is a well-described postoperative complication, occurring in 1to 31% of relatively small cohorts and case series. Given the relative infrequency of instability, there remains a need for a comprehensive review of instability with a focus on risk factors and management. Our goal of this systematic review is to describe the prevalence, risk factors, and management strategies for instability following RSA.

Methods

A systematic review of the PubMed, EMBASE, MEDLINE, Scopus, and Cochrane Library databases was performed according to PRISMA guidelines. Inclusion criteria included primary RSA cohorts ≥ 100 patients, revision RSA cohorts of any size, and minimum 1-year follow-up. The primary outcome of interest was postoperative instability. MINORS criteria were used to assess study bias. Descriptive statistical analysis was performed with data reported as ranges.

Results

Seventeen studies that included 7885 cases of RSA were reviewed. The mean follow-up ranged from 12 to 84 months. Mean age ranged from 64 to 77 years old, and males represented 19 to 39% of cohorts. There were 204 (2.5%) dislocations in 7885 cases, accounting for a rate of instability from 0.4 to 49% across all studies. By intervention, instability rates ranged from 1 to 5% (primary RSA cases), 1 to 49% (revision RSA cases only), and 0.4 to 10% (mixed cohorts). Subscapularis insufficiency and proximal humerus fractures, and fracture sequelae (malunion and nonunion) were identified as risk factors for instability. Closed reduction and casting and revision RSA were reported as successful treatment strategies with acceptable rates of stable prostheses (28-100% and 55-100%, respectively, across studies). Hemiarthroplasty or resection arthroplasty due to recurrent instability was not uncommon after 2 or more episodes of instability.

Conclusion

Instability following RSA occurs infrequently (1-5%) following primary RSA and more commonly following revision RSA (1-49%). RSA for acute proximal humerus fracture and fracture sequelae carries a higher risk of instability. Subscapularis repair appears to be a protective factor. While instability may be successfully treated with closed management or revision RSA, recurrent instability may ultimately require hemiarthroplasty or resection arthroplasty.

Posttreatment Imaging of the Shoulder

The shoulder joint is vulnerable for injuries following trauma and in the context of sporting activities. Degenerative rotator cuff disease is also a common entity. Conservative therapy is often not indicated or does not lead to the desired success, so surgical intervention is necessary. Routine follow-ups, but also persistent complaints, delayed healing, or recurrent trauma, usually need postoperative imaging of the shoulder. The choice of the adequate imaging modality and technique is important to reach the correct diagnosis. Additionally, knowledge of the most common surgical procedures, as well as typical normal findings and expected pathologies on different imaging modalities, is crucial for the radiologist to play a relevant role in the postoperative diagnostic process. This article addresses postoperative imaging after rotator cuff repair, shoulder arthroplasty, and surgery for shoulder stabilization with an emphasis on computed tomography and magnetic resonance imaging.

Stemless reverse total shoulder arthroplasty: a systematic review

BACKGROUND

The use of reverse total shoulder arthroplasty and stemless anatomic total shoulder replacement has been increasing in the United States every year. Stemless humeral components in reverse total shoulder arthroplasty are only approved for clinical trials in the United States with an investigational device exception with limited data.

METHODS

A systematic review on stemless reverse total shoulder arthroplasty was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A search was conducted on November 25, 2020, using the MEDLINE/PubMed, Cochrane, and Embase databases. All articles were reviewed by 2 independent evaluators, with any conflicts or issues resolved by consensus or a final decision by the senior author. The primary outcomes extracted were complications, radiographic results, and outcome scores.

RESULTS

We evaluated 10 studies that used either the Total Evolutive Shoulder System (TESS) or Verso implant. There were 430 total patients and 437 total procedures; 266 patients in the TESS group underwent a total of 272 procedures, and 164 patients in the Verso group underwent a total of 165 procedures. The mean age at the time of surgery was 73.8 years (range, 38-93 years). The mean follow-up period ranged from 6.4 to 101.6 months per study. There was an overall trend of improved clinical outcome scores, a 0.2% humeral component loosening rate, and an 11.2% complication rate.

CONCLUSIONS

This review shows that the clinical and functional outcomes following stemless or metaphyseal reverse total shoulder arthroplasty are quite promising, especially with the low rate of humeral-sided complications. There continues to be a need for additional long-term studies and randomized clinical trials.

Remote Follow-up of Shoulder Arthroplasty Patients During COVID-19 Pandemic - Is This the way Forward?

Background

The COVID-19 Pandemic has affected the way health care systems function across the globe. Apart from eliminating the risk of being in a vulnerable environment during the pandemic such as a hospital setting, virtual arthroplasty follow-up reduces the demand on funding and resources on the National Health Services (NHS).

Methods

We retrospectively reviewed our shoulder arthroplasty patients (55) operated between October 2018 to November 2020 at both our hospital sites. For remote follow-up, patients were contacted on a scheduled appointment date via telephone by an orthopaedic surgeon to enquire about their wound, pain and function. Patients were questioned as per questionnaire from the Oxford Shoulder Score (OSS) and American Shoulder and Elbow Surgeons (ASES) Standardised Assessment form.

Results

50 patients were included in the final data set after excluding those who had died (5 patients). All patients had had final x-rays with full Covid-19 precautions at the time of final follow-up. No patient had wound problems except one who had concerns of wound appearance. There were no cases of notching, impingement, deep infection, dislocation or nerve injury. Of the 50 patients, 40 (80%) patients were satisfied to have a remote follow-up. 36 (72%) patients said they wouldn't mind a remote follow-up appointment.

Conclusion

Remote follow-up via audio consultation may be an effective alternative to in person visits after shoulder arthroplasty. Patients in this series demonstrated a high level of satisfaction with virtual visits and post-operative complications were effectively identified.

Minimum 2-year outcomes of reverse total shoulder arthroplasty for fracture: how does acute arthroplasty compare with salvage?

BACKGROUND

The objective of our study was to compare patient-reported outcome measures, range of motion (ROM), complication rates, and reoperation rates after reverse total shoulder arthroplasty (rTSA) for proximal humeral fractures between patients treated acutely (≤30 days after injury), those treated after initial nonoperative treatment (>30 days after injury), and those treated after failed open reduction-internal fixation. Secondarily, we aimed to identify any patient-, injury-, or surgery-related factors independently associated with our response variables.

METHODS

We identified 576 patients who sustained a proximal humeral fracture treated with primary or revision shoulder arthroplasty between January 2003 and August 2018. The final cohort included 153 patients. Multivariable analysis was used to assess whether explanatory variables were associated with our response variables.

RESULTS

Initial nonoperative treatment compared with acute rTSA was associated with worse Shoulder Subjective Value (P = .04), Shoulder Pain and Disability Index score (P = .03), and Shoulder Pain and Disability Index disability subscale score (P = .03). Only depression was independently associated with worse visual analog scale pain score (P = .04). There was no significant difference in postoperative ROM between the initial treatment groups. Older age was associated with decreased ROM in all planes. Additionally, ipsilateral upper-extremity injury was associated with decreased active abduction (P = .03), and cemented humeral stems were associated with decreased passive abduction (P = .03). Initial nonoperative treatment was associated with increased complication rates (odds ratio, 3.65; 95% confidence interval, 1.11-12.01), and male sex was associated with higher rates of reoperation (odds ratio, 3.53; 95% confidence interval, 1.31-9.51).

CONCLUSIONS

Patients who undergo initial periods of nonoperative management have worse functional outcomes and higher complication rates than those who undergo acute rTSA for proximal humeral fractures. Patients who undergo rTSA after failed open reduction-internal fixation show no difference in patient-reported outcomes compared with those who undergo acute rTSA. In addition, male patients are at higher risk of reoperation, whereas older patients are at risk of decreased ROM. Patients with preoperative depression are at risk of increased pain at 2 years after surgery.

Reverse Shoulder Arthroplasty, Deltopectoral Approach vs. Anterosuperior Approach: An Overview of the Literature

Reverse shoulder arthroplasty (RSA) has become an optimal treatment for numerous orthopedic entities, such as rotator cuff tear arthropathies, pseudoparalysis, fracture sequelae, acute fractures, failed arthroplasties, osteoarthritis, and rheumatoid arthritis, and is linked with relief of topical pain and regaining of functionality. Presently, RSA has been conducted through anterosuperior (AS) or deltopectoral (DP) approach. The aim of the study was to discuss both approaches and to examine broadly their features to render a comparison in terms of clinical effectiveness. An electronic search in PubMed, EMBASE, and Google Scholar databases was performed, using combinations of the following keywords: RSA, DP approach, AS approach, notching, and cuff tear arthropathy. A total of 61 studies were found, and 16 relevant articles were eventually included. Currently published literature has not shown significant diversities in the clinical course due to approach preference; risk of instability seems to be greater in DP approach, while regarding scapular notching and fracture rates the findings were conflicted. In addition, the AS approach has been associated with decreased risk of acromial and scapular spine fractures. In conclusion, both surgical approaches have shown similar clinical outcomes and effectiveness concerning pain and restoring range of motion (ROM) in rotator cuff tear arthropathies. In the future, further investigations based on large-scale well-designed studies are required to address clinical gaps allowing in-depth comparison of both approaches.

Failed Reverse Total Shoulder Arthroplasty: What Are Our Bailouts?

PURPOSE OF REVIEW

As the population continues to age and indications continue to expand, the number of reverse total shoulder arthroplasty (RSTA) procedures has increased significantly. While RTSA is an effective solution to many shoulder problems, it is not without complications. Furthermore, as the number of RTSA procedures increases, so will the number of complications following this procedure. While some complications can be managed with revision RTSA, there are some complications that, unfortunately, cannot. The purpose of this review is to discuss the revision options for failed RTSA.

RECENT FINDINGS

While there has been a significant amount of recent literature surrounding RTSA, much of this literature has been aimed at improving outcomes for primary RTSA by improving glenoid placement, maximizing range of motion, etc., or improving outcomes following conversion of another surgery to RTSA [1••, 2, 3]. There has been little evidence surrounding options for failed RTSA that cannot be salvaged to a revision RTSA. These options are limited and often involve resection arthroplasty and hemiarthroplasty, although neither option provides patients with significant function of the shoulder [4, 5•]. Complications following RTSA are becoming more common as the number of RTSA continues to increase. Furthermore, as the indications for RTSA expand, the complications will continue to increase as this implant is used to tackle more difficult problems about the shoulder. When possible, the etiology of the problem with the RTSA should be addressed and may involve component revision, bone grafting, etc. When the problem cannot be solved with revision RTSA, then the patient can be converted to a hemiarthroplasty, or have a resection arthroplasty, with the understanding that their shoulder function will be limited.

Biomechanics of anatomic and reverse shoulder arthroplasty

The biomechanics of the shoulder relies on careful balancing between stability and mobility. A thorough understanding of normal and degenerative shoulder anatomy is necessary, as the goal of anatomic total shoulder arthroplasty is to reproduce premorbid shoulder kinematics.With reported joint reaction forces up to 2.4 times bodyweight, failure to restore anatomy and therefore provide a stable fulcrum will result in early implant failure secondary to glenoid loosening.The high variability of proximal humeral anatomy can be addressed with modular stems or stemless humeral components. The development of three-dimensional planning has led to a better understanding of the complex nature of glenoid bone deformity in eccentric osteoarthritis.The treatment of cuff tear arthropathy patients was revolutionized by the arrival of Grammont's reverse shoulder arthroplasty. The initial design medialized the centre of rotation and distalized the humerus, allowing up to a 42% increase in the deltoid moment arm.More modern reverse designs have maintained the element of restored stability but sought a more anatomic postoperative position to minimize complications and maximize rotational range of motion. Cite this article: EFORT Open Rev 2021;6:918-931. DOI: 10.1302/2058-5241.6.210014.

Augmented-Reality-Assisted K-Wire Placement for Glenoid Component Positioning in Reversed Shoulder Arthroplasty: A Proof-of-Concept Study

The accuracy of the implant's post-operative position and orientation in reverse shoulder arthroplasty is known to play a significant role in both clinical and functional outcomes. Whilst technologies such as navigation and robotics have demonstrated superior radiological outcomes in many fields of surgery, the impact of augmented reality (AR) assistance in the operating room is still unknown. Malposition of the glenoid component in shoulder arthroplasty is known to result in implant failure and early revision surgery. The use of AR has many promising advantages, including allowing the detailed study of patient-specific anatomy without the need for invasive procedures such as arthroscopy to interrogate the joint's articular surface. In addition, this technology has the potential to assist surgeons intraoperatively in aiding the guidance of surgical tools. It offers the prospect of increased component placement accuracy, reduced surgical procedure time, and improved radiological and functional outcomes, without recourse to the use of large navigation or robotic instruments, with their associated high overhead costs. This feasibility study describes the surgical workflow from a standardised CT protocol, via 3D reconstruction, 3D planning, and use of a commercial AR headset, to AR-assisted k-wire placement. Post-operative outcome was measured using a high-resolution laser scanner on the patient-specific 3D printed bone. In this proof-of-concept study, the discrepancy between the planned and the achieved glenoid entry point and guide-wire orientation was approximately 3 mm with a mean angulation error of 5°.

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.

Inferior tilt of the glenoid leads to medialization and increases impingement on the scapular neck in reverse shoulder arthroplasty

BACKGROUND

In reverse shoulder arthroplasty, Inferior tilt was originally promoted to decrease rates of baseplate failure. However, the literature is conflicting regarding the effect of tilt on scapular neck impingement, which has been associated with an increased risk of notching, increased risk of impingement-related instability, and decreased range of motion. We hypothesized that inferior tilt of -10° would lead to increased medialization and increased scapular neck impingement compared with 0° of tilt.

METHODS

Twenty patients without glenoid bone loss undergoing reverse shoulder arthroplasty (RSA) at a single institution underwent computed tomography scans of the entire scapula and proximal humerus for preoperative planning. For each patient, we digitally implanted a 25-mm glenoid baseplate flush with the inferior rim of the glenoid. We then simulated impingement-free range of motion with 16 different implant configurations: glenoid tilt (0° vs. -10°), baseplate lateralization (0 mm vs. +6 mm), glenosphere size (36 mm vs. 42 mm), and neck-shaft angle (135° vs. 145°). The primary endpoint was external rotation with the arm at the side (ERS), which is the primary mode of both notching and impingement-related instability, and the secondary endpoint was adduction (ADD). We recorded the RSA angle, preoperative scapular neck length (SNL), and postoperative SNL. Data were compared by paired t tests and a multivariable regression analysis.

RESULTS

In every simulation, inferior tilt led to more impingement on the scapular neck. Inferior tilt of the glenoid component was associated with a mean 27% decrease in impingement-free external rotation (P < .01 in all cases) and a mean 32% decrease in impingement-free ADD (P < .01 in all cases). Inferior tilt removed 3.2 mm of additional SNL (P < .001). Multivariable regression analysis showed that lateralization had the most impact on impingement-free external rotation and ADD (P < .001), followed by glenosphere size (P < .001), neck-shaft angle (P < .001), postoperative SNL (P < .001), glenoid tilt (P = .001), inclination (P < .001), and RSA angle (P = .023 for ERS and P = .025 for ADD).

CONCLUSION

Relative to 0° of tilt of the baseplate, inferior tilt of -10° was associated with increased scapular neck impingement in ERS and ADD, likely a result of the increased medialization necessary to seat an inferiorly tilted implant, which shortens the scapular neck and brings the humerus closer to the scapula. This scapular neck impingement increases the risk of notching and impingement-related instability.

Influence of humeral stem inclination in reverse shoulder arthroplasty on range of motion: a meta-analysis

Hypothesis

The reverse shoulder arthroplasty, as introduced by Grammont, has had many modifications over time. One of these modifications was reducing the neck-shaft angle (NSA) from 155 degrees to 135 degrees. Biomechanical studies indicated that lowering the NSA increases external rotation and reduces abduction and the incidence of scapular notching. The purpose of this study was to compare range of motion, functional outcome measures, and complications in patients undergoing reverse shoulder arthroplasty, depending on the NSA, through a systematic review and meta-analysis.

Methods

A literature search was conducted (articles published from January 1985 to January 2020) in the PubMed/MEDLINE, Embase, and CINAHL databases and the Cochrane library. All studies reporting outcomes after primary reverse shoulder arthroplasty for osteoarthritis and rotator cuff-related disease were included. Patients were divided into 2 groups: a medialized design (MD) with an NSA of 150-155 degrees and a lateralized design (LD) with an NSA of less than 150 degrees. Pooled effects were calculated in the form of mean differences and 95% confidence intervals (CIs). Risk of bias was assessed using the Risk Of Bias In Non-Randomized Studies - of Interventions tool for non-Randomized Controlled Trials and the Risk Of Bias 2 tool for Randomized Controlled Trials.

Results

A total of 21 studies and 3134 arthroplasties were included: 1366 with an MD and 1678 with an LD. The mean age was 73.0 years (MD 74.0 and LD 72.5). A direct comparative meta-analysis was not feasible, and therefore, all data were compared using the minimal clinically important difference. The MD group demonstrated a larger improvement in abduction (56.76°, 95% CI 37.03-76.49) than the LD group (48.52°, 95% CI 28.27-68.78), however the LD group demonstrated a larger improvement in external rotation with the arm at the side (MD: 7.69°, 95% CI 0.01-15.37; LD: 16.14° 95% CI 7.18-25.09). When looking at the postoperative range of motion, the MD group had more abduction than the LD group (MD: 136.28°, 95% CI 127.36-145.20; LD: 127.77° 95% CI 117.02-138.52). Both designs had a comparable improvement in the Constant Murley score (MD 42.04 points, LD 41.14 points). Lowering the NSA was accompanied by a decrease in dislocation rate (MD: 4.6%; LD: 1.4%; P value .037) and notching rate (MD: 40.3%; LD: 17.3%; P value <.0001).

Conclusion

In our analysis, lowering the NSA decreases the amount of abduction but increases the amount of external rotation. This change in range of motion is accompanied by less scapular notching and dislocations. There is no clear impact on functional outcome measures.

A novel method for localization of the maximum glenoid bone defect during reverse shoulder arthroplasty

Background

Management of glenoid bone defects during reverse shoulder arthroplasty remains a challenge. The aim of our study was to preoperatively localize the maximal depth of glenoid bone defects in relation to glenoid reaming.

Methods

Thirty preoperative shoulder computed tomography scans were collected. Three assessors created standardized surgical plans, using 3-dimensional (3D) computed tomography–based Blueprint planning software in which the reaming axis was held constant at zero degrees of version and inclination. Each plan resulted in a 2-dimensional (2D) image of the reamer’s contact on the glenoid and a corresponding 3D representation of the glenoid bone defect. The position of the maximum glenoid defect was localized on both the 2D and 3D images. Descriptive statistics were calculated. The correlation between angles from 2D and 3D images was assessed, and intraclass correlation was used to assess inter-rater and intrarater reliability.

Results

Twenty-eight patients were included. The overall mean difference between 2D and 3D angles was 5.4° (standard deviation 5.2°). The correlation between 2D and 3D angles was almost perfect. Intraclass correlation results demonstrated near-perfect agreement. The maximal glenoid defect was within 5% of a circle (or +/- 9°) from perpendicular to the high-side ream line in 85.1% of comparisons and was within 10% of a circle in 97.6% of comparisons.

Conclusion

Using Blueprint planning software, we have demonstrated with almost perfect agreement among 3 assessors that when the reaming axis is held constant, the maximum glenoid bone defect is reliably located perpendicular to the glenoid ream line.

Implant Selection for Proximal Humerus Fractures

Proximal humerus fractures (PHF) are a common orthopedic injury; however, their treatment remains largely controversial with evidence supporting a wide array of treatments. Although many injuries can be treated nonoperatively, there has been much debate about surgical management of PHF. A detailed review of the literature was performed relative to operative management options specifically related to implant choices. Although no definitive answers are available regarding best practice, there is literature to guide operative decision-making and implant selection based on both patient- and surgeon-specific factors.

Reverse total shoulder arthroplasty clinical and patient-reported outcomes and complications stratified by preoperative diagnosis: a systematic review

OBJECTIVE

This systematic review aimed to investigate differences in clinical outcomes, patient-reported outcomes (PROs), and complication types and rates among preoperative diagnoses following reverse total shoulder arthroplasty (RTSA): rotator cuff tear arthropathy, primary osteoarthritis, massive irreparable rotator cuff tear, proximal humeral fracture, rheumatoid arthritis (RA), and revision of anatomic arthroplasty (Rev).

LITERATURE SEARCH

Three electronic databases were searched from inception to January 2020.

STUDY SELECTION CRITERIA

The inclusion criteria were (1) patients with a minimum age of 60 years who underwent RTSA for the stated preoperative diagnoses, (2) a minimum of 2 years' follow-up, and (3) preoperative and postoperative values for clinical outcomes and PROs.

DATA SYNTHESIS

Risk of bias was determined by the Methodological Index for Non-randomized Studies tool and the modified Downs and Black tool. Weighted means for clinical outcomes and PROs were calculated for each preoperative diagnosis.

RESULTS

A total of 53 studies were included, of which 36 (68%) were level IV retrospective case series. According to the Methodological Index for Non-randomized Studies tool, 33 studies (62%) showed a high risk of bias; the 3 randomized controlled trials showed a low risk of bias on the modified Downs and Black tool. RTSA improved clinical outcomes and PROs for all preoperative diagnoses. The Rev group had poorer final outcomes as noted by a lower American Shoulder and Elbow Surgeons score (69) and lower pain score (1.8) compared with the other preoperative diagnoses (78-82 and 0.4-1.4, respectively). The RA group showed the highest complication rate (28%), whereas the osteoarthritis group showed the lowest rate (1.4%).

CONCLUSION

Studies in the RTSA literature predominantly showed a high risk of bias. All preoperative diagnoses showed improvements; Rev patients showed the worse clinical outcomes and PROs, and RA patients showed higher complication rates. The preoperative diagnosis in RTSA patients can impact outcomes and complications.

Biological sex impacts perioperative complications after reverse shoulder arthroplasty for proximal humeral fracture

Background

The purpose of this study was to determine the difference in complication rates between males and females undergoing reverse shoulder arthroplasty for proximal humerus fractures. We hypothesized that (1) females were more likely to undergo reverse shoulder arthroplasty for fracture, and (2) males were more likely to sustain a perioperative complication.

Methods

The National Surgical Quality Improvement Program database was queried to identify patients who underwent reverse shoulder arthroplasty for proximal humerus fracture between 2011 and 2018. Patients were stratified based on biological sex. Patient demographics, comorbidities, and 30-day perioperative complication rates were collected. Univariate analyses and multiple variable logistic regression modeling were performed.

Results

About 905 patients were included in the analysis—175 (19.3%) were male and 730 (80.7%) were female. Males were more likely to sustain perioperative complications (26.3% vs. 14.1%; P < .001)—pneumonia (2.9% vs. 0.5%; P = .016), unplanned intubation (2.3% vs. 0.4%; P = .029), and unplanned reoperation (9.1% vs. 1.1%; P < .001). On multivariate analysis, males were at a 2.4-fold increase risk of developing any complication (OR = 2.38 [95% CI 1.55-3.65]; P < .001) and a 10-fold increase risk of returning to the operating room for an unplanned reoperation (OR = 10.59 [95% CI 4.23-27.49]; P < .001) compared with females.

Conclusion

Females were more likely to undergo reverse shoulder arthroplasty for proximal humerus fracture, but males were at increased risk of sustaining short-term complications. This study provides useful information for clinicians to consider when counseling their patients during the perioperative period.

Reverse Shoulder Arthroplasty with <i>Latissimus Dorsi</i> Transfer for Humerus Fractures Sequelae

Relevance. Fractures of the proximal humerus occupy the 3rd place in the structure of fractures in the elderly. Failure to treat these injuries leads to irreversible changes in the shoulder. The main treatment for the latter is arthroplasty. The surgical treatment of this category of patients is still a difficult task. The purpose of this study was to compare the effectiveness of standard reverse arthroplasty with reverse arthroplasty in combination with the reconstruction of the external rotators of the shoulder or transposition of the latissimus dorsi. Materials and Methods. The retrospective evaluation of treatment results of 96 patients with consequences of shoulder injuries was conducted. Of these, 51 patients underwent standard reverse arthroplasty (group I), and 45 patients (group II) underwent arthroplasty with reconstruction of the external rotators of the shoulder or transposition of the latissimus dorsi. The female patients accounted for 68.8%. The duration of the injury varied from 8 months to 2.5 years, the follow-up — from 1 to 7 years (Me = 3.5). The results were assessed with VAS, ASES, UCLA scales. Results. The positive outcomes were observed in most patients. Complications: dislocations of the endoprosthesis occurred in 16.7%, infectious complications — in 5.2%, shoulder component instability — in 2.1%, fracture of the humeral diaphysis — in 3.1%, neurovascular bundle injury — in 2.1% of cases. In the patients of group I, dislocations occurred significantly more often than in the patients of group II. To reduce the risk of complications, a rational tactic has been developed for treating patients with consequences of shoulder injuries. If electroneuromyography values from the deltoid muscle were less than 40% of the contralateral side, or if mineral bone density T-score was less than 2.5 SD, arthroplasty was not performed. During arthroplasty, it is necessary to perform the direct suturing of the of the infraspinatus and teres minor tendons to the humerus. If it is impossible, the latissimus dorsi transfer is indicated. Conclusion. Reverse arthroplasty in the treatment of the humerus fractures sequelae is an effective technique. To reduce the risk of complications, it is necessary to provide the additional stability of the endoprosthesis by reconstruction of the external rotators or latissimus dorsi transfer. It is advisable to refrain from arthroplasty in cases of severe deltoid hypotrophy and severe osteoporosis.

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.

Core Set of Radiographic Parameters for Shoulder Arthroplasty Monitoring: Criteria Defined by an International Delphi Consensus Process

Some unfavorable local events following shoulder arthroplasty occur without the patient experiencing symptoms and yet may be detected on diagnostic imaging, thereby serving as indicators of complications that may require revision. Our aim was to create a standardized protocol for an image-based monitoring process for assessing patients who are asymptomatic following shoulder arthroplasty.

Methods

A Delphi exercise was implemented with the participation of an international panel of experienced shoulder surgeons. On the basis of expert opinion from a core steering group, an initial list of imaging parameters for shoulder arthroplasty monitoring of asymptomatic patients was developed and reviewed by panel members. The most appropriate imaging modality was identified. Between each survey, all feedback was considered in order to revise the proposed core set with its definitions and specifications. Consensus was reached upon a two-thirds agreement.

Results

Three online surveys were administered, with 98 surgeons responding to the first and/or the second survey. The response rate for the final survey was 74%. Final parameter definitions were organized in 7 categories (implant migration, radiolucency around implant and implant loosening, signs of shoulder displacement, bone resorption and formation, wear of implant articular surfaces, fractures around the implant, and implant breakage and disassembly) and approved with 85% to 100% agreement. Seventy-eight percent of the panel members agreed on a minimum radiographic imaging schedule: standard anteroposterior and axial (alternatively, Y) views made within 6 weeks after implantation and between 3 and 6 months as well as at 12 months post-surgery.

Conclusions

Our work presents a monitoring tool developed with international consensus for the assessment of asymptomatic patients after shoulder arthroplasty and including a structured core set of radiographic parameters. Clinical application and scientific evaluation of the monitoring process are needed.

Clinical Relevance

This represents a major step toward the standardization of shoulder arthroplasty radiographic monitoring for routine quality controls and research investigations.

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.