Defining the Volume-Outcome Relationship in Reverse Shoulder Arthroplasty: A Nationwide Analysis

Geographic Variability in the Management of Anterior Glenohumeral Instability: A Binational Analysis

Background

The Bankart and Latarjet procedures are the 2 most commonly performed procedures for stabilization of anterior glenohumeral instability around the world. The aim of this study was to describe actual trends in surgery for anterior instability in the United States and in France.

Hypothesis

Glenohumeral stabilization surgery overall is becoming more frequent in France and in the United States, with an increasing number of Latarjet procedures having been performed in each country in recent years.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A retrospective review was performed using French and American databases from 2009 to 2018. Procedure codes MEMA005 and MEMC004 were pulled from the French National Health Insurance System and Current Procedural Terminology codes 23455, 29806, and 23462 were pulled from IBM MarketScan. During this period, 73,914 patients underwent anterior shoulder stabilization surgery in France and 391,521 in the United States. For each year and the global period, the estimated number of Bankart procedures in the United States was compared with the number of French procedures. The same comparison was done for Latarjet procedures. The sex ratio was compared using chi-square testing. The mean age was compared using a Student t test.

Results

The Bankart procedure represents 98% of the shoulder stabilization procedures in the United States, but the Latarjet procedure is becoming more common in the United States, having increased by 154% during the 10-year study period. In France, the Latarjet procedure represents 75% of the surgeries, having increased by 40% during the 10-year study period. However, use of the Bankart procedure in France increased from 11.2/100,000 in 2009 to 13.4/100,000 in 2018.

Conclusion

This study demonstrated that, overall, use of the Latarjet procedure has been increasing over the last decade in both the United States and France. However, there remains a divergence in the treatment of anterior shoulder instability between the 2 countries. The Latarjet procedure remains the preferred treatment option in France for anterior shoulder instability (75% Latarjet vs 25% Bankart), whereas the Bankart procedure is dominant within the United States (98% Bankart vs 2% Latarjet). When breaking data down by age groups, more Bankart procedures are being performed on younger patients, and in both countries the incidences of women requiring these surgeries are increasing. The authors hope this study will serve as a foundation for future prospective studies establishing evidence-based algorithms to guide the treatment of anterior instability and provide a root cause analysis on why different surgeons choose a specific procedure to treat this problem.

The effect of surgeon volume on complications after total shoulder arthroplasty: a nationwide assessment

BACKGROUND

Increased surgeon volume has been demonstrated to correlate with improved outcomes after orthopedic surgery. However, there is a lack of data demonstrating the effect of surgeon volume on outcomes after total shoulder arthroplasty.

METHODS

The PearlDiver Mariner database was retrospectively queried from the years 2010 to 2022. Patients who underwent shoulder arthroplasty were selected using the Current Procedural Terminology code 23472 (total shoulder arthroplasty). Patients younger than 40 years, those who underwent revision arthroplasty, and cases of bilateral arthroplasty were excluded. In addition, cases with a history of fracture, infection, or malignancy before surgery were excluded. Only surgeons who performed a minimum of 10 cases were selected, and PearlDiver was queried using their provider ID codes. Primary outcome measures included 90-day, 1-year, and 2-year rates of complication and reoperation. A Bonferroni correction was used in which the significance threshold was set at P ≤ .00082.

RESULTS

A total of 155,560 patients met inclusion criteria and were retained for analysis. The 90th percentile for surgeon volume was determined to be 112 cases during the study period. Surgeons above the 90th percentile (n = 340) operated on 68,531 patients, whereas surgeons below the 90th percentile (n = 3038) operated on 87,029 patients. Surgeons in the high-volume group were significantly more likely to have completed a Shoulder and Elbow fellowship (P < .001) and less likely to have no fellowship training or fellowship training outside of Shoulder and Elbow or Sports Medicine (P < .001). Low-volume surgeons operated on patients with higher baseline comorbidities (Charlson Comorbidity Index [CCI]: 2.01 vs. 1.85, P < .001). After adjusting for age, gender, CCI, obesity, and tobacco use, high-volume surgeons experienced lower rates of medical complications including renal failure (P < .001), anemia (P < .001), and urinary tract infection (P < .001). All-cause readmission (0.90, P < .001), reoperation at 90 days (odds ratio: 0.75, P < .001), and reoperation at 1 year (odds ratio: 0.86, P < .001) were significantly lower among high-volume surgeons. High-volume surgeons exhibited lower rates of various complications including prosthetic joint infection (90 days: P < .001, 1 year: P < .001, and 2 years: P < .001), periprosthetic fracture (90 days: P < .001, 1 year: P < .001, and 2 years: P < .001), and all complications (90 days: P < .001 and 1 year: P < .001).

CONCLUSIONS

Surgeons who perform a high volume of total shoulder arthroplasty are more likely to operate on healthier patients than surgeons who perform a lower volume of cases. When compared with low-volume surgeons, and after adjusting for age, gender, and CCI, high-volume surgeons have a significantly lower overall complication rate. Despite this lower complication rate, high-volume surgeons are responsible for a decreasing portion of shoulder arthroplasty since 2016.

Reassessing Glycemic Control: A Novel Method for 90-Day Major Complication Stratification Based on Hemoglobin A1c and Same-Day Glucose Levels for Patients Undergoing Total Knee Arthroplasty

BACKGROUND

Glucose levels obtained on the day of surgery may be predictive of complications following total knee arthroplasty (TKA). Established glucose thresholds for TKA are either nonspecific or have low predictive power. Therefore, the purpose of this study was to create data-driven hemoglobin A1c (HbA1c) and same-day glucose thresholds associated with varying risks of 90-day major and surgical site infection (SSI) complications following TKA.

METHODS

Stratum-specific likelihood ratio analysis was conducted to determine data-driven HbA1c and glucose strata associated with varying risks of 90-day major and SSI complications. Each strata was then propensity score matched to the lowest strata based on age, sex, hypertension, heart failure, chronic obstructive pulmonary disorder, and obesity. The risk ratio (RR) for complications in each stratum with respect to the lowest matched stratum was analyzed.

RESULTS

Four data-driven HbA1c (%) strata (4.5 to 5.9, 6.0 to 6.4, 6.5 to 7.9, and 8.0+) and two same-day glucose (mg/dL) strata (60 to 189 and 190+) were identified that predicted 90-day major complications. When compared to the propensity-matched lowest strata (4.5 to 5.9%), the risk of 90-day major complications sequentially increased as the HbA1c (%) strata increased: 6.0 to 6.4 (RR: 1.23; P = 0.024), 6.5 to 7.9 (RR: 1.38; P < 0.001), and 8.0+ (RR: 2.0; P < 0.001). When compared to the propensity-matched lowest strata (60 to 189 mg/dL), the 190+ mg/dL strata had a higher risk of 90-day major complications (RR: 1.18; P = 0.016). No HbA1c or same-day glucose strata had significantly different risks of 90-day SSI.

CONCLUSIONS

The multiple strata identified for HbA1c demonstrate that a single HbA1c cutoff as identified in prior literature may be missing a larger picture for risk stratification. The threshold identified for same-day glucose can be utilized in day-of-surgery glycemic control guidelines to further reduce the risk of 90-day major complications.

Cost-Volume Analysis of Primary Total Knee and Hip Arthroplasty in the United States

BACKGROUND

Utilization of total knee arthroplasty (TKA) and total hip arthroplasty (THA) arthroplasty is increasing along with associated hospitalization costs. A contemporary analysis of the impact of hospital case volume on the costs of TKA and THA is lacking.

METHODS

Adults undergoing primary elective TKA or THA who had a diagnosis of osteoarthritis were identified from an inpatient all-payer database from 2012 to 2019. Operative volume was ascertained with restrictive cubic spline analysis. The volume corresponding to the inflection point of the spline was used to stratify hospitals as high volume (HVH) or low volume (LVH). Multivariable regression models were developed to examine the association of volume with hospitalization costs, adverse events, lengths of stay, and nonhome discharges.

RESULTS

Of the 7,781,233 patients undergoing TKA or THA over the study period, 73.1% of primary TKA and 77.1% of primary THA were managed at HVH. On adjustment for patient and hospital covariates, treatment at high-volume TKA or THA hospitals was associated with a cost decrement of $2,200 (95% confidence interval, 2,900 to 2,400, P < 0.001), and $1,900 (95% confidence interval, 2,100 to 1,600), respectively. Notably, the disparity in hospitalization costs between HVH and LVH markedly increased during the study period (P < 0.001).

CONCLUSIONS

Greater TKA and THA volume was associated with reduced hospitalization costs. These findings suggest that regionalization of care to experienced hospitals may improve the value of orthopaedic surgical care.

Independent predictors of 90-day readmission in patients with inflammatory bowel disease: a nationwide retrospective study

BACKGROUND AND AIMS

There is a paucity of literature that comprehensively investigates risk factors for inflammatory bowel disease (IBD) readmissions on a national scale. In this study, we look to identify independent risk factors for readmission, including psychosocial factors, in patients admitted with a primary diagnosis of ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

We performed a retrospective cohort study using data from the Nationwide Readmissions Database. We identified cohorts of adult patients (n = 28 473) who required inpatient admission for UC or CD in the United States in the year 2020. Multivariate logistic regression models controlling for confounding variables were used to identify independent predictors of 90-day readmission.

RESULTS

Patients were identified who required hospitalization for UC (n = 11 476) and CD (n = 16 997). In patients with UC, younger age, male sex, and transfusion requirement during index hospitalization were all independently predictive of increased 90-day readmission (all P < .05). Psychosocial factors predictive of readmission include alcohol use disorder, drug abuse, and poverty (all P < .05). In patients with CD, younger age and chronic pain were both predictive of increased readmissions (all P < .05). Psychosocial factors predictive of readmission include lower income quartile, uninsured status, depression, drug abuse, nicotine dependence, and opioid use disorder (all P < .05).

CONCLUSIONS

This study identifies several risk factors for readmission in patients with IBD, many of which are potentially modifiable psychosocial factors. Closer follow-up, possibly via virtual modalities, as well as alternative treatment strategies, should be considered in patients with IBD at higher risk of readmission.

Reverse total shoulder arthroplasty policy in Germany - an analysis of the health care reality from 2010 to 2022

BACKGROUND

The last few years have been characterized by increasing numbers of reverse shoulder arthroplasties. In addition to the classic indication of cuff tear arthropathy, the use for complex proximal humeral fractures (PHFs) and rotator cuff tear (RCT) in very old patients have been established. The objective of this study is to clarify and substantiate the above statements specifically for Germany (based on official data from 2010 to 2022). Since substantial changes in the structure of the population are expected over time, all data must be adjusted for these changes. The hypotheses are (1) the German population is ageing with a shift to more elderly patients over time, and (2) the general use of shoulder arthroplasty (total anatomic - shoulder arthroplasty (aTSA) and reverse - rTSA) has increased during the time period, but the effect is beyond the shift of age stratification but attributable to a change of hospital admissions and surgical therapy for PHF and RCT.

METHODS

In this retrospective study, data were collected from the National Bureau of Statistics in Germany for the period of 2010 to 2022. Three different data sources were combined for the analysis: a database regarding the structure of the population in age groups for every year, a database reporting relevant operation codes, and the data on hospital admissions based on ICD-10 codes. The relevant data were extracted and combined using Excel spread sheets (Microsoft Corporation, version 2019). Absolute numbers are reported and adjusted for 100.000 inhabitants in each age group in order to calculate the incidence.

RESULTS

Only slight change in absolute numbers of the population (n = 81751602 to 84358845, +3%) was observed, but a substantial shift toward the group of elderly people: the peak age group has shifted from 40-50 to 55-65. The number of TSA has significantly increased (n = 15000 to n = 28117, +187%; incidence 18.35 to 28.53, +155%). The number of rTSA has largely increased (n = 5326 to n = 24067, +452%; incidence 6.51 to 28.53, +438%), whereas the number of aTSA steadily decreased (n = 9674 to n = 4050, -42%; incidence 11.83 to 4.80, -41%). The number of revision arthroplasties has increased 1.8-fold (n = 2179 to n = 3893; incidence 1.7-fold). The peak revision rate shifted from the age group 70-75 toward 90- 95; 76% of all revision cases were performed in patients 65 years and older in 2010 increasing to 87% in 2022. Hospital admissions for PHF have increased 7.8-fold (n = 110091 to n = 810907). The peak in the age groups has shifted by a decade from 70-74 to 80-84. The absolute number of surgical therapy for PHF has decreased (n = 12816 to n = 9562, 75%; incidence 72%). The number of hospital admissions for RCT increased by 2.6-fold (n = 47004 to n = 124096; incidence + 255%). The number of surgical interventions for RCT increased by 3.7% (n = 51350 to n = 53294; incidence 62.8 to 63.2). Combined numbers for the operative therapy of PHF, RCT, and rTSA show an increase of +124% (n = 69491 to n = 86715) with a peak shift on one decade toward the age group 60-94 with 79% of the patients in 2022. The increased use of rTSA, as expressed by incidence, is strongly correlated with the increasing proportion of people aged 65 and over.

CONCLUSION

The data show a substantial increase in the use of shoulder arthroplasty procedures in Germany in the observed time period, with the main driving factor being the increase of rTSA, whereas aTSA numbers decreased. The combined analysis of the hospital admissions and operative procedures performed to treat PHF and RCT indicated a shift of treatment numbers from open reduction and internal fixation and rotator cuff repair in the elderly toward the alternative use of rTSA in this age group. The observed shift of the stratification of age groups gives a further explanation for the increase in rTSA use: the number of patients in the age groups with the typical and alternative indications for rTSA substantially increased with a shift of the peak age group towards the elderly of one decade. Healthcare officials should be aware of these fundamental changes in the population, which create further demands on the health care system. The expected continuation of rising numbers of rTSA needs to be addressed by providing adequate resources such as reimbursement, surgical and rehabilitation facilities, and staff.

Reverse total shoulder arthroplasty within 6 weeks of proximal humerus fracture is associated with the lowest risk of revision

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) has become an increasingly popular treatment strategy in the management of complex proximal humeral fractures (PHFs). However, no definitive consensus has been reached regarding the optimal surgical timing of RTSA following PHF, particularly considering nonoperative management is often a viable option. Therefore, the aim of this study was (1) to identify optimal timing intervals that maximize the likelihood of revision following RTSA and (2) to determine differences in revision etiologies using the identified timing intervals.

METHODS

A retrospective cohort analysis of patients undergoing PHF-indicated RTSA from 2010 to 2021 was conducted using a national administrative claims database. Stratum-specific likelihood ratio (SSLR) analysis was conducted to determine data-driven timing strata between PHF and RTSA that maximized the likelihood of revision surgery within 2 years of RTSA. To control for confounders, multivariable regression analysis was conducted to confirm the identified data-driven strata's association with 2-year revision rates as well as compare the likelihood of various indications for revision including mechanical loosening, dislocation, periprosthetic joint infection (PJI), and periprosthetic fracture (PPF).

RESULTS

In total, 11,707 patients undergoing TSA following PHF were included in this study. SSLR analysis identified 2 timing categories: 0-6 weeks and 7-52 weeks from the time of PHF to TSA surgery. Relative to the 0-6-week cohort, the 7-52-week cohort was more likely to undergo revision surgery within 2 years (OR 1.93, P < .001). Moreover, the 7-52-week cohort had significantly higher odds of revision indicated for dislocation (OR 2.24, P < .001), mechanical loosening (OR 1.71, P < .001), PJI (OR 1.74, P < .001), and PPF (OR 1.96, P < .001).

CONCLUSIONS

Using SSLR, we were successful in identifying 2 data-driven timing strata between PHF and RTSA that maximized the likelihood of 2-year revision surgery. As it can be difficult to determine whether RTSA or nonoperative management is initially more appropriate, considering the results of this study, an early trial of 4-6 weeks of nonoperative management may be appropriate without altering the risks associated with RTSA.

Mixed-reality improves execution of templated glenoid component positioning in shoulder arthroplasty: a CT imaging analysis

INTRODUCTION

Glenoid placement is critical for successful outcomes in total shoulder arthroplasty (TSA). Preoperative templating with three-dimensional imaging has improved implant positioning, but deviations from the planned inclination and version still occur. Mixed-Reality (MR) is a novel technology that allows surgeons intra-operative access to three-dimensional imaging and templates, capable of overlaying the surgical field to help guide component positioning. The purpose of this study was to compare the execution of preoperative templates using MR vs.standard instruments (SIs).

METHODS

Retrospective review of 97 total shoulder arthroplasties (18 anatomic, 79 reverse) from a single high-volume shoulder surgeon between January 2021 and February 2023, including only primary diagnoses of osteoarthritis, rotator cuff arthropathy, or a massive irreparable rotator cuff tear. To be included, patients needed a templated preoperative plan and then a postoperative computed tomography scan. Allocation to MR vs. SI was based on availability of the MR headset, industry technical personnel, and the templated preoperative plan loaded into the software, but preoperative or intraoperative patient factors did not contribute to the allocation decision. Postoperative inclination and version were measured by two independent, blinded physicians and compared to the preoperative template. From these measurements, we calculated the mean difference, standard deviation (SD), and variance to compare MR and SI.

RESULTS

Comparing 25 MR to 72 SI cases, MR significantly improved both inclination (P < .001) and version (P < .001). Specifically, MR improved the mean difference from preoperative templates (by 1.9° inclination, 2.4° version), narrowed the SD (by 1.7° inclination, 1.8° version), and decreased the variance (11.7-3.0 inclination, 14.9-4.3 version). A scatterplot of the data demonstrates a concentration of MR cases within 5° of plan relative to SI cases typically within 10° of plan. There was no difference in operative time.

CONCLUSION

MR improved the accuracy and precision of glenoid positioning. Although it is unlikely that 2° makes a detectable clinical difference, our results demonstrate the potential ability for technology like MR to narrow the bell curve and decrease the outliers in glenoid placement. This will be particularly relevant as MR and other similar technologies continue to evolve into more effective methods in guiding surgical execution.

Higher complication rates following primary total shoulder arthroplasty in patients presenting from areas of higher social deprivation

Aims

The aim of this study was to characterize the influence of social deprivation on the rate of complications, readmissions, and revisions following primary total shoulder arthroplasty (TSA), using the Social Deprivation Index (SDI). The SDI is a composite measurement, in percentages, of seven demographic characteristics: living in poverty, with < 12 years of education, single-parent households, living in rented or overcrowded housing, households without a car, and unemployed adults aged < 65 years.

Methods

Patients aged ≥ 40 years, who underwent primary TSA between 2011 and 2017, were identified using International Classification of Diseases (ICD)-9 Clinical Modification and ICD-10 procedure codes for TSA in the New York Statewide Planning and Research Cooperative System database. Readmission, reoperation, and other complications were analyzed using multivariable Cox proportional hazards regression controlling for SDI, age, ethnicity, insurance status, and Charlson Comorbidity Index.

Results

A total of 17,698 patients with a mean age of 69 years (SD 9.6), of whom 57.7% were female, underwent TSA during this time and 4,020 (22.7%) had at least one complication. A total of 8,113 patients (45.8%) had at least one comorbidity, and the median SDI in those who developed complications 12 months postoperatively was significantly greater than in those without a complication (33 vs 38; p < 0.001). Patients from areas with higher deprivation had increased one-, three-, and 12-month rates of readmission, dislocation, humeral fracture, urinary tract infection, deep vein thrombosis, and wound complications, as well as a higher three-month rate of pulmonary embolism (all p < 0.05).

Conclusion

Beyond medical complications, we found that patients with increased social deprivation had higher rates of humeral fracture and dislocation following primary TSA. The large sample size of this study, and the outcomes that were measured, add to the literature greatly in comparison with other large database studies involving TSA. These findings allow orthopaedic surgeons practising in under-served or low-volume areas to identify patients who may be at greater risk of developing complications.

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.

Does hospital setting influence shoulder replacement revision rate? A national comparison of outcomes between private and public settings

BACKGROUND

Australian healthcare relies on both private and public sectors to meet the demand for surgical care. Rapid growth of shoulder replacement surgery highlights a disparity in service provision, with two-thirds occurring privately. This study aimed to assess the influence of hospital setting on shoulder replacement revision rate at a national level.

METHODS

All primary shoulder replacements recorded by the Australian Orthopaedic Association National Joint Replacement Registry from April 2004 to December 2020 were included. Private and public settings were compared for stemmed total shoulder replacement (sTSR) for osteoarthritis (OA), reverse total shoulder replacement (rTSR) for OA/cuff arthropathy (CA), and rTSR for fracture. The primary outcome was cumulative percent revision (CPR), with Kaplan-Meier estimates of survivorship to determine differences between private and public hospitals, recorded as hazard ratios (HR). Secondary analyses investigated differences between hospital settings, targeting hospital outliers for revision and prosthesis selection.

RESULTS

Primary sTSR (OA) demonstrated a higher revision rate in private hospitals compared to public hospitals (HR = 1.27; P = 0.001), as did rTSR (OA/CA) after 3 months (HR = 1.33; P = 0.003). However, no significant difference was observed for primary rTSR (fracture) (HR = 1.10; P = 0.484). Restricting rTSR (OA/CA) to the best performing prosthesis combinations eliminated the difference between private and public outcomes (HR 1.10; P = 0.415). No other secondary analysis altered the primary result.

CONCLUSIONS

Differences exist between private and public hospitals for revision rate following primary shoulder replacement. Prosthesis selection accounts for some of the variation. Further analysis into patient specific characteristics is necessary to better understand these disparities.

Anterosuperior versus deltopectoral approach for primary reverse total shoulder arthroplasty

Aims

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

Methods

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

Results

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

Conclusion

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

Higher Surgeon Volume is Associated With a Lower Rate of Subsequent Revision Procedures After Total Shoulder Arthroplasty: A National Analysis

BACKGROUND

Studies assessing the relationship between surgeon volume and outcomes have shown mixed results, depending on the specific procedure analyzed. This volume relationship has not been well studied in patients undergoing total shoulder arthroplasty (TSA), but it should be, because this procedure is common, expensive, and potentially morbid.

QUESTIONS/PURPOSES

We performed this study to assess the association between increasing surgeon volume and decreasing rate of revision at 2 years for (1) anatomic TSA (aTSA) and (2) reverse TSA (rTSA) in the United States.

METHODS

In this retrospective study, we used Centers for Medicare and Medicaid Services (CMS) fee-for-service inpatient and outpatient data from 2015 to 2021 to study the association between annual surgeon aTSA and rTSA volume and 2-year revision shoulder procedures after the initial surgery. The CMS database was chosen for this study because it is a national sample and can be used to follow patients over time. We included patients with Diagnosis-related Group code 483 and Current Procedural Terminology code 23472 for TSA (these codes include both aTSA and rTSA). We used International Classification of Diseases, Tenth Revision, procedural codes. Patients who underwent shoulder arthroplasty for fracture (10% [17,524 of 173,242]) were excluded. We studied the variables associated with the subsequent procedure rate through a generalized linear model, controlling for confounders such as patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, hospital size and teaching status, assuming a binomial distribution with the dependent variable being whether an episode had at least one subsequent procedure within 2 years. The regression was fitted with standard errors clustered at the hospital level, combining all TSAs and within the aTSA and rTSA groups, respectively. Hospital and surgeon yearly volumes were calculated by including all TSAs, primary procedure and subsequent, during the study period. Other hospital-level and surgeon-level characteristics were obtained through public files from the CMS. The CMS Hierarchical Condition Category risk score was controlled because it is a measure reflecting the expected future health costs for each patient based on the patient's demographics and chronic illnesses. We then converted regression coefficients to the percentage change in the odds of having a subsequent procedure.

RESULTS

After controlling for confounding variables including patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, and hospital size and teaching status, we found that an annual surgeon volume of ≥ 10 aTSAs was associated with a 27% decreased odds of revision within 2 years (95% confidence interval 13% to 39%; p < 0.001), while surgeon volume of ≥ 29 aTSAs was associated with a 33% decreased odds of revision within 2 years (95% CI 18% to 45%; p < 0.001) compared with a volume of fewer than four aTSAs per year. Annual surgeon volume of ≥ 29 rTSAs was associated with a 26% decreased odds of revision within 2 years (95% CI 9% to 39%; p < 0.001).

CONCLUSION

Surgeons should consider modalities such as virtual planning software, templating, or enhanced surgeon training to aid lower-volume surgeons who perform aTSA and rTSA. More research is needed to assess the value of these modalities and their relationship with the rates of subsequent revision.

LEVEL OF EVIDENCE

Level III, therapeutic study.

An Analysis of Shoulder Surgeon Volume on Surgeon Competency, Hospital Costs, and Adverse Events: A Systematic Review

Purpose

The purpose of this systematic review is to assess the impact of shoulder surgeon volume of common shoulder procedures on hospital/surgeon efficiency, adverse events, and hospital costs.

Methods

Four online databases (PubMed, Embase, MEDLINE, and CENTRAL) were searched for literature on the influence of surgeon volume on outcomes for shoulder surgery, from data inception to October 1, 2020. The Methodological Index for Non-Randomized Studies tool was used to assess study quality. Data are presented descriptively.

Results

Twelve studies encompassing 150,898 patients were included in this review. The distribution of surgery type was rotator cuff repair (53.7%; n = 81,066), shoulder arthroplasty (35.7%; n = 53,833), and ORIF (10.6%; n = 15,999). Higher surgeon volume for rotator cuff repairs was associated with lower surgical time, length of stay, costs, and reoperation/readmission rates. For shoulder arthroplasty, higher surgeon volume was associated with lower length of stay, costs, surgical time, non-routine disposition, blood loss, reoperation/readmission, and complications. As for ORIF, higher surgeon volume was associated with lower length of stay, costs, and complications.

Conclusion

A high surgical volume leads to improved results for hospital/surgeon efficiency and reduces adverse events and hospital costs across various orthopaedic procedures. Hospitals and physicians can use this information to develop and adhere to policies and practices that contribute to more efficient and better-quality care for patients.

Level of Evidence

III.

The Impact of Frailty Is Age Dependent in Patients Undergoing Primary Total Knee Arthroplasty: The Age-Adjusted Modified Frailty Index

BACKGROUND

Frailty is a well-established risk factor in patients undergoing total knee arthroplasty (TKA). How age modifies the impact of frailty on outcomes in these patients, however, remains unknown. In this study, we aimed to describe and evaluate the applicability of a novel risk stratification tool-the age-adjusted modified Frailty Index (aamFI)-in patients undergoing TKA.

METHODS

A national database was queried for all patients undergoing primary TKA from 2015 to 2019. There were 271,271 patients who met inclusion criteria for this study. First, outcomes were compared between chronologically young and old frail patients. In accordance with previous studies, the 75th percentile of age of all included patients (73 years) was used as a binary cutoff. Then, frailty was classified using the novel aamFI, which constitutes the 5-item mFI with the addition of 1 point for patients ≥73 years. Multivariable logistic regressions were then used to investigate the relationship between aamFI and postoperative outcomes.

RESULTS

Frail patients ≥73 years had a higher incidence of complications compared to frail patients <73 years. There was a strong association between aamFI and complications. An aamFI of ≥3 (reference aamFI of 0) was associated with an increased odds of 30-day mortality (odds ratio [OR] 8.6, 95% CI 5.0-14.8), any complication (OR 3.1, 95% CI 2.9-3.3), deep vein thrombosis (OR 1.5, 95% CI 1.2-1.8), and nonhome discharge (OR 6.1, 95% CI 5.8-6.4; all P < .001).

CONCLUSION

Although frailty negatively influences outcomes following TKA in patients of all ages, chronologically old, frail patients are particularly vulnerable. The aamFI accounts for this and represents a simple, but powerful tool for stratifying risk in patients undergoing primary TKA.

Identification of Independent Predictors of Increased 90-Day Complication and Revision Rates Following Total Elbow Arthroplasty

Introduction

Total elbow arthroplasty (TEA) is an increasingly popular surgical option for many debilitating conditions of the elbow. There currently exists a paucity of literature regarding patient and hospital factors that lead to inferior outcomes following TEA. The purpose of this study is to identify independent predictors of increased complication and revision rates following TEA.

Methods

The National Readmissions Database (NRD) was queried from 2011 to 2018 to identify all cases of TEA (n = 8932). Relevant patient demographic factors, comorbidities, and hospital characteristics were identified and run in a univariate binomial logistic regression model. All significant variables were included in a multivariate binomial logistic regression model for data analysis.

Results

Independent predictors of increased complication rates included age, female sex, Medicare and Medicaid payer status, medium bed-sized center, and 18 of 34 medical comorbidities (all P < .05). Independent predictors of increased revision rates included medium bed-sized centers, non-teaching hospital status, chronic pulmonary disease, depression, and pulmonary circulatory disorders (all P < .05).

Conclusion

This study identified several patient and hospital characteristics that are independently associated with both increased complication and revision rates following TEA. This information can aid orthopedic surgeons during shared decision making when considering TEA in patients.

Level of Evidence

Level III, retrospective cohort study.

Medicaid payer status is associated with increased 90-day morbidity and resource utilization following primary shoulder arthroplasty: a propensity score-matched analysis

BACKGROUND

Medicaid payer status has been shown to affect risk-adjusted patient outcomes and health care utilization across multiple medical specialties and orthopedic procedures. However, there is a paucity of data regarding the impact of Medicaid payer status on 90-day morbidity and resource utilization following primary shoulder arthroplasty (reverse total shoulder arthroplasty [rTSA], anatomic total shoulder arthroplasty [aTSA], and hemiarthroplasty [HA]). The purpose of this study was to examine 90-day readmission and reoperation rates, hospital length of stay (LOS), and direct cost following primary shoulder arthroplasty in the Medicaid population.

METHODS

The National Readmission Database was queried for all patients undergoing primary aTSA, rTSA, and HA from 2011 to 2016. Medicaid or non-Medicaid payer status was determined. Patient demographic characteristics and comorbidities, along with 90-day readmission, 90-day reoperation, LOS, and inflation-adjusted cost, were queried. Propensity score matching was used to control for baseline differences in cohorts that could be acting as confounders in the exposure-outcome relationship. This was achieved with 1-to-1 propensity score matching between Medicaid and non-Medicaid patients. Odds ratios (ORs) and 95% confidence intervals (CIs) for 90-day readmission and reoperation rates were calculated, and a comparison of LOS and cost was performed between the propensity score-matched cohorts.

RESULTS

A total of 4667 Medicaid and 161,147 non-Medicaid patients were identified from the 2011-2016 National Readmission Databases. Propensity score analysis was performed, and 4637 Medicaid patients were matched to 4637 non-Medicaid patients; each group comprised 1504 rTSAs (32.4%), 1934 aTSAs (41.7%), and 1199 HAs (25.9%). Patients with Medicaid payer status yielded significant increases in the 90-day all-cause readmission rate of 11.6% vs. 9.3% (P < .001; OR, 1.28 [95% CI, 1.12-1.46]), 90-day shoulder-related readmission rate of 3.3% vs. 2.3% (P = .004; OR, 1.44 [95% CI, 1.12-1.85]), and 90-day reoperation rate of 2.0% vs. 1.3% (P = .008; OR, 1.54 [95% CI, 1.12-1.94]). Furthermore, there was an increased risk of an extended LOS (ie, LOS > 2 days) (28.4% vs. 25.7%; P = .004; OR, 1.14 [95% CI, 1.04-1.25]) along with increased direct cost (median, $17,612 vs. $16,775; P < .001).

DISCUSSION

This study demonstrates that Medicaid payer status is independently associated with increased 90-day readmission and reoperation rates, LOS, and direct cost following primary shoulder arthroplasty. Providers may have a disincentive to treat patient populations who require increased resource utilization following surgery. Risk adjustment models accounting for Medicaid payer status will be necessary to ensure good access to care for this patient population by avoiding penalties for physicians and hospital systems.

Prediction of total healthcare cost following total shoulder arthroplasty utilizing machine learning

BACKGROUND

Given the increase in demand in treatment of glenohumeral arthritis with anatomic total (aTSA) and reverse shoulder arthroplasty (RTSA), it is imperative to improve quality of patient care while controlling costs as private and federal insurers continue its gradual transition toward bundled payment models. Big data analytics with machine learning shows promise in predicting health care costs. This is significant as cost prediction may help control cost by enabling health care systems to appropriately allocate resources that help mitigate the cause of increased cost.

METHODS

The Nationwide Readmissions Database (NRD) was accessed in 2018. The database was queried for all primary aTSA and RTSA by International Classification of Diseases, Tenth Revision (ICD-10) procedure codes: 0RRJ0JZ and 0RRK0JZ for aTSA and 0RRK00Z and 0RRJ00Z for RTSA. Procedures were categorized by diagnoses: osteoarthritis (OA), rheumatoid arthritis (RA), avascular necrosis (AVN), fracture, and rotator cuff arthropathy (RCA). Costs were calculated by utilizing the total hospital charge and each hospital's cost-to-charge ratio. Hospital characteristics were included, such as volume of procedures performed by the respective hospital for the calendar year and wage index, which represents the relative average hospital wage for the respective geographic area. Unplanned readmissions within 90 days were calculated using unique patient identifiers, and cost of readmissions was added to the total admission cost to represent the short-term perioperative health care cost. Machine learning algorithms were used to predict patients with immediate postoperative admission costs greater than 1 standard deviation from the mean, and readmissions.

RESULTS

A total of 49,354 patients were isolated for analysis, with an average patient age of 69.9 ± 9.6 years. The average perioperative cost of care was $18,843 ± $10,165. In total, there were 4279 all-cause readmissions, resulting in an average cost of $13,871.00 ± $14,301.06 per readmission. Wage index, hospital volume, patient age, readmissions, and diagnosis-related group severity were the factors most correlated with the total cost of care. The logistic regression and random forest algorithms were equivalent in predicting the total cost of care (area under the receiver operating characteristic curve = 0.83).

CONCLUSION

After shoulder arthroplasty, there is significant variability in cumulative hospital costs, and this is largely affected by readmissions. Hospital characteristics, such as geographic area and volume, are key determinants of overall health care cost. When accounting for this, machine learning algorithms may predict cases with high likelihood of increased resource utilization and/or readmission.

A Novel Method for Stratification of Major Complication Risk Using Body Mass Index Thresholds for Patients Undergoing Total Hip Arthroplasty: A National Cohort of 224,413 Patients

INTRODUCTION

Elevated body mass index (BMI) is associated with complications following Total Hip Arthroplasty (THA). Since obese individuals are almost 10 times more likely to require THA compared to non-obese individuals, we need to understand the risk-benefit continuum while considering THA in obese patients. We aimed to determine data-driven thresholds for BMI at which the risk of major complications following THA increases significantly.

METHODS

Patients were identified in a national database who underwent primary THA from 2010 to 2020. BMI thresholds were identified using the stratum-specific likelihood ratio (SSLR) methodology, which is an adaptive technique that allows for identification of BMI cut-offs, at which the risk of major complications is increased significantly . BMI cutoffs identified using SSLR were used to create a logistic regression model.

RESULTS

A total of 224,413 patients were identified with a mean age of 66 ± 10, BMI 32 ± 6.7, and 7,186 (3%) sustained a major complication. BMI thresholds were defined as 19-31, 32-37, 38-49 and 50+. Overall, the absolute risk of major complications increased from 2.9% in the lowest BMI strata to 7.5% in the highest BMI strata. Compared to patients with a BMI between 19-31, the odds of sustaining a major complication sequentially increased by 1.2, 1.6, and 2.5-times for patients in each higher BMI strata (all, P < .05).

CONCLUSIONS

We have identified BMI cutoffs using SSLR that categorizes patients into four categories of risk for major complications in a nationally representative patient sample. These thresholds can be used in the surgical decision-making process between patients and surgeons.

The Effects of Social and Demographic Factors on High-Volume Hospital and Surgeon Care in Shoulder Arthroplasty

INTRODUCTION

This study seeks to evaluate (1) the relationship between hospital and surgeon volumes of shoulder arthroplasty and complication rates and (2) patient demographics/socioeconomic factors that may affect access to high-volume shoulder arthroplasty care.

METHODS

Adults older than 40 years who underwent shoulder arthroplasty between 2011 and 2015 were identified in the New York Statewide Planning and Research Cooperative System database using International Classification of Disease 9/10 and Current Procedural Terminology codes. Medical/surgical complications were compared across surgeon and facility volumes. The effects of demographic factors were analyzed to determine the relationship between such factors and surgeon/facility volume in shoulder arthroplasty.

RESULTS

Seven thousand seven hundred eighty-five patients were included. Older, Hispanic/African American, socially deprived, nonprivately insured patients were more likely to be treated by low-volume facilities. Low-volume facilities had higher rates of readmission, urinary tract infection, renal failure, pneumonia, and cellulitis than high-volume facilities. Low-volume surgeons had patients with longer hospital lengths of stay.

DISCUSSION

Important differences in patient socioeconomic factors exist in access to high-volume surgical care in shoulder arthroplasty, with older, minority, and underinsured patients markedly more likely to receive care by low-volume surgeons and facilities. This may highlight an area of potential focus to improve access to high-volume care.

Fixed- vs. variable-angle humeral neck cut in anatomic total shoulder arthroplasty: a randomized controlled trial

BACKGROUND

Variable neck-shaft angle (NSA) stemmed humeral components have been incorporated into certain implant designs to better re-create normal anatomy in total shoulder arthroplasty (TSA). The purpose of this study was to determine if premorbid glenohumeral joint anatomy is better restored with a fixed- vs. variable-NSA prosthesis.

METHODS

A randomized controlled trial was performed including 50 patients with osteoarthritis indicated for primary anatomic TSA. Patients were randomized preoperatively to receive either a variable- (n = 26) or fixed-NSA (n = 24) prosthesis. Humeral neck cut in the variable-NSA group matched the patient's anatomic neck, with prosthetic NSA of 127.5°, 132.5°, and 137.5° available. Fixed-NSA cuts were made with an intramedullary guide of 132.5°. Preoperative and postoperative radiographs were evaluated for specific radiographic anatomic variables: NSA, head thickness, tuberosity-to-head height, head offset, articular arc, greater tuberosity offset, and center of rotation (COR). Postoperative radiographic criteria were compared between groups.

RESULTS

No differences were found between groups in demographics or preoperative radiographic measures. When comparing average difference in preoperative and postoperative measurements in the fixed-NSA group, the humeral head offset from the humeral shaft axis significantly decreased by 1.4 mm (P = .046), and the COR moved superiorly (3.0 mm, P = .002) without significant medialization or lateralization. In the variable angle group, humeral head offset decreased but did not reach significance (1.2 mm, P = .091), and the COR also moved superiorly (2.9 mm, P < .001) without significant medialization or lateralization. All remaining radiographic parameters did not significantly change from pre- to postoperative imaging. In comparing the fixed- and variable-NSA groups' net change from the premorbid measurements, no significant differences were found in tuberosity-to-head height, head offset, or COR position in both the horizontal and vertical planes.

CONCLUSIONS

Both fixed- and variable-NSA anatomic TSA humeral components demonstrate adequate restoration of premorbid anatomy radiographically.

The Age-Adjusted Modified Frailty Index: An Improved Risk Stratification Tool for Patients Undergoing Primary Total Hip Arthroplasty

BACKGROUND

Frailty and increasing age are well-established risk factors in patients undergoing total hip arthroplasty (THA). However, these variables have only been considered independently. This study assesses the interplay between age and frailty and introduces a novel age-adjusted modified frailty index (aamFI) for more refined risk stratification of THA patients.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2015 to 2019 for patients undergoing primary THA. First, outcomes were compared between chronologically younger and older frail patients. Then, to establish the aamFI, one additional point was added to the previously described mFI-5 for patients aged ≥73 years (the 75th percentile for age in our study population). The association of aamFI with postoperative complications and resource utilization was then analyzed categorically.

RESULTS

A total of 165,957 THA patients were evaluated. Older frail patients had a higher incidence of complications than younger frail patients. Regression analysis demonstrated a strong association between aamFI and complications. For instance, an aamFI of ≥3 (compared to aamFI of 0) was associated with an increased odds of mortality (OR: 22.01, 95% confidence interval [CI] 11.62-41.68), any complication (OR: 3.50, 95% CI 3.23-3.80), deep vein thrombosis (OR: 2.85, 95% CI 2.03-4.01), and nonhome discharge (OR 9.61, 95% CI 9.04-10.21; all P < .001).

CONCLUSION

Chronologically, older patients are impacted more by frailty than younger patients. The aamFI accounts for this and outperforms the mFI-5 in prediction of postoperative complications and resource utilization in patients undergoing primary THA.

Assessing the hospital volume-outcome relationship in total elbow arthroplasty

BACKGROUND

Total elbow arthroplasty (TEA) is an effective intervention for multiple elbow disorders including complex fracture in elderly patients, post-traumatic arthropathy, inflammatory arthropathy, and distal humeral nonunion. Given its known therapeutic value and low utilization rate, an investigation into the thresholds for TEA institutional volume-outcome relationships is warranted. The purpose of this study was to identify TEA volume thresholds that serve as predictors of institutional outcomes including complications, readmissions, revisions, cost of care, length of stay (LOS), and non-home discharge. We hypothesized that increased institutional volume would be associated with decreased 90-day adverse outcomes and resource utilization.

METHODS

The Nationwide Readmission Database was queried from 2010 to 2017 to identify all cases of TEA. Hospital volume was calculated using a unique hospital identifier and divided into quartiles. Outcomes such as complications, readmissions, revisions, cost of care, LOS, and non-home discharge were then analyzed by quartile. The same outcomes were assessed via stratum-specific likelihood ratio (SSLR) analysis to define volume strata among institutions.

RESULTS

SSLR analysis defined statistically significant hospital volume categories for each 90-day outcome. The volume category with the lowest complication rate was ≥21 TEAs per year (5.6%). The volume categories with the lowest readmission rates were 1-3 TEAs per year (4.7%) and ≥18 TEAs per year (9.2%). Revision rates were lowest in the volume categories of 1-5 TEAs per year (0.1%) and ≥18 TEAs per year (0.1%). Hospitals with ≥21 TEAs per year had the lowest cost of care and the highest rate of extended LOS (>2 days). SSLR analysis showed that non-home discharges decreased in a stepwise manner as volume increased. The lowest non-home discharge rate was associated with the volume category of ≥22 TEAs per year (20.3%).

CONCLUSION

This study defines TEA volume strata for institutional outcomes. The highest TEA volume strata were associated with the lowest rates of 90-day complications, revisions, and non-home discharges and the lowest cost of care. This trend is likely attributable to the benefits of high-volume institutional experience and standardized patient-care processes.

Evidence-Based Hospital Procedural Volumes as Predictors of Outcomes After Revision Hip Arthroplasty

BACKGROUND

The aim of this study is to define the evidence-based institutional volume-outcome relationship in revision hip arthroplasty. We hypothesized that high-volume centers would be associated with superior outcomes, and that stratum-specific likelihood ratio (SSLR) analysis would delineate concrete volume thresholds for optimizing outcomes.

METHODS

The Nationwide Readmission Database was queried from 2011 to 2016 for patients undergoing revision hip arthroplasty. SSLR analysis was used to determine hospital volume cutoffs specific for outcomes of interest. Volume categories were confirmed with multivariate regression.

RESULTS

SSLR analysis produced distinct hospital volume cutoffs for all outcomes. Each subsequent volume threshold diminished patients' risk for adverse outcomes. Tertiles were identified for 90-day infection (≤6, 7-51, ≥52 cases per year). Quartiles were found for 90-day readmission (≤5, 6-15, 16-79, ≥80), 90-day prosthesis-related complication (≤5, 6-16, 17-65, ≥66), 90-day dislocation (≤5, 6-19, 20-79, ≥80), and non-home discharge (≤5, 6-15, 16-40, and ≥41). Quintiles were generated for extended length of stay >2 days (≤2, 3-10, 11-20, 21-30, ≥31). Heptiles were produced for medical complications within 90 days (≤2, 3-8, 9-16, 17-51, 52-89, ≥90).

CONCLUSION

This is the first known study to define evidence-based thresholds for the impact of hospital volume on revision joint arthroplasty. This supports the notion that institutional volume functions as a surrogate for protocolized interdisciplinary coordination of care and surgical experience, and that high-volume centers offer enhanced outcomes for complex cases. Additional studies should investigate the potential role for incentivization of such institutions, as they offer optimal outcomes for revision hip arthroplasty.

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.