Faculty Bibliography

BACKGROUND:The goal of this study was to utilize preoperative computed-tomography(CT) scans to identify differences in the Hounsfield units(HU) of the acromion in patients who did and did not develop a postoperative acromial and scapular-spine fracture(ASF) after primary reverse total shoulder arthroplasty (rTSA). METHODS:A retrospective analysis was performed at a single institution. All patients undergoing a rTSA with either a 135° neck/shaft angle(NSA) humeral inlay design combined with a lateralized center-of-rotation(COR) glenosphere or a 145° NSA onlay combined with a medialized COR glenosphere design between 2011-2021 with a minimum follow-up of 24-months were included. Demographic characteristics and clinical outcome metric scores were recorded. Preoperative CT scans were analyzed to obtain acromion trabecular bone density measurements in HU in each zone of the scapula based on the Levy classification. Radiographic parameters were evaluated to determine their association with ASF. RESULTS:In total 263-patients were included, 140-patients with a 135° NSA humeral-inlay design;123-patients with a 145° NSA humeral-onlay design. There were no significant differences in baseline demographics between cohorts. The rate of ASF was 6.4%(9/140) for the 135° NSA-inlay-design versus 2.4%(3/123) in the 145° NSA-onlay design. In the non-fracture cohort there was a linear increase in bone density from zone-1(173.9HU)→zone-3(396.5HU)(lateral→medial). In the fracture cohort there was a decrease in bone density from zone-1(282.6HU)→zone-3(154.5HU). Measuring preoperative bone density in all Levy specific fracture-zones resulted in an AUC of 0.96 correlating to excellent predictive value. A threshold cutoff of 99.9 resulted in a sensitivity of 91.6% and specificity of 75.3%. A HU of 99.9 in any of the three-zones resulted in OR 5.1(p<0.0001) for sustaining an ASF postoperatively. A threshold of<50HU was associated with an 8-times higher-likelihood of developing a fracture in that specific zone. Greater than 5° of superior tilt in combination with ≥24mm of distalization was associated with an OR 6.4(p=0.0004) of sustaining an ASF. CONCLUSION/CONCLUSIONS:The current study demonstrates an accurate method of measuring HU at each of the described Levy fracture zones with excellent predictability of patients who are at risk of an ASF following rTSA. Additionally, we found that a HU threshold of <50 HU at any of the three Levy zones was associated with a nearly 8 times higher likelihood of developing a fracture in that specific zone. Lastly, we found that >5° of superior tilt in combination with ≥24mm of distalization was associated with 6.4 times higher likelihood of sustaining an ASF agnostic to prosthesis design.

BACKGROUND:Guidance technology in total joint arthroplasty has gained popularity over the last few decades. Computer-assisted navigation (CAN) was recently introduced for glenoid implantation in total shoulder arthroplasty (TSA). However, utilization trends of CAN TSA are not currently known. This study aims to determine the prevalence and trends of CAN usage in TSA from its introduction in 2017 until 2023. METHODS:A retrospective review was performed of all TSAs (anatomic TSA [aTSA] or reverse TSA [rTSA]) implanted using a single computer navigation shoulder system (ExactechGPS; Gainseville, FL, USA). Intraoperative navigation was performed for the glenoid component only. Utilization of CAN was reported per year to determine trends in the prevalence of CAN cases, number of users, new users, dropped users, high-volume users (>50 CAN cases/year), and the number of cases completed by high-volume users. The data was also stratified by type of TSA (aTSA vs. rTSA) and type of glenoid component used (augmented or non-augmented). RESULTS:From 2017 to 2023, navigated TSAs increased from 654 to 9777 cases per year, with a greater increase in navigated rTSA than aTSA volume. The number of CAN cases using augmented implants grew 1435% while non-augmented implants grew 1352%. By 2023, the overall number of CAN users increased from 79 to 667 users. High-volume CAN surgeons increased to 50 users by 2023. Over this period, the number of CAN TSA performed by high-volume surgeons increased more rapidly than the actual number of high-volume surgeons per year. CONCLUSIONS:This study demonstrates an exponential increase in the use of CAN for TSA in the last eight years. This increase is driven by progressive growth in both the volume of new users as well as CAN TSAs performed by existing users by several hundred folds. These upwards trends in utilization of guidance technology for TSA are likely to continue in future.

BACKGROUND:Although Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (P-UE) has been validated in upper extremity orthopedics, its ability to capture a patient's functional recovery after arthroscopic rotator cuff repair (aRCR), as measured by its responsiveness, is minimal in the early postoperative period. The primary purpose of this study is to determine if the addition of PROMIS Pain Intensity (P-Intensity) or Pain Interference (P-Interference) scores to PROMIS UE improves the responsiveness throughout the 1-year postoperative period after aRCR. METHODS:This prospective, longitudinal study included 100 patients who underwent aRCR. Patients completed P-UE, P-Interference, P-Intensity, American Shoulder and Elbow Surgeons, and Western Ontario Rotator Cuff Index scores preoperatively and at 2 weeks, 6 weeks, 3 months, 6 months, and 12 months after surgery. Responsiveness at each time point relative to preoperative baseline and 1-way analysis of variance with post hoc analysis was conducted for each PROM. The responsiveness of the outcome score was determined using the effect size, graded as small (0.2), medium (0.5), or large (0.8). The Pearson correlation coefficient (r) was determined between these instruments at each time point. RESULTS:In isolation, P-UE, P-Interference, and P-Intensity showed a medium-large ability to detect change (positive and negative) throughout the 1-year postoperative period. The addition of PROMIS pain scores to P-UE improved the responsiveness of the instrument (from medium to a large effect size) starting at 3 months and continued throughout the 12-month follow-up period. Although the addition of pain scores increases the response burden for PROMIS, this was still lower than the response burden for the legacy outcome scores (P < .05). CONCLUSION/CONCLUSIONS:The addition of PROMIS pain instruments improves the responsiveness of the P-UE function score in patients undergoing aRCR.

BACKGROUND:Patient-Reported Outcome Measurement Information Systems (PROMIS) is increasingly being utilized across the United States as a patient-reported outcome evaluation tool for a wide variety of musculoskeletal conditions. However, PROMIS Upper Extremity (P-UE) physical function has demonstrated limited responsiveness in the early postoperative period after total shoulder arthroplasty (TSA). The aim of this study is to determine if addition of PROMIS Pain Interference (P-Interference) or Pain Intensity (P-Intensity) scores improve the ability to detect postoperative changes in the 1-year postoperative period following TSA. METHODS:Patients who were indicated for and elected to undergo TSA between 2020 and 2022 were prospectively enrolled. Prospective data were collected for patient surveys (American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test, P-UE, P-Interference and P-Intensity) at the 2-week, 6-week, 3-month, 6-month, and 12-month timepoints. Instrument responsiveness for each PROM was evaluated using the effect size (ES; Cohen d). Responsiveness was defined by the absolute values of each measurement, previously reported as small (0.2), medium (0.5), or large (0.8). Statistical analysis (2 sample t-tests and Fisher's tests) was performed using R studio version 4.2.3 (Boston, MA, USA). RESULTS:A total of 127 subjects were enrolled in this study. All survey instruments demonstrated large responsiveness (>0.8) at 3, 6, and 12 months. P-Intensity was the only instrument to demonstrate large responsiveness at 2-weeks with its addition to P-UE showing an improved responsiveness at all-time points. Moreover, the addition of P-Intensity had a lower response burden at all-time points when compared to the legacy measures (ASES, Simple Shoulder Test, and Oxford Shoulder Score) at all-time points albeit no difference to ASES (P = .55) at 12-months after surgery. P-Interference and other legacy scores demonstrated large responsiveness starting at 6-weeks postoperatively. CONCLUSION/CONCLUSIONS:The responsiveness of PROMIS UE can be improved by coupling the outcome measure to P-Intensity scores with a significantly lower response burden when compared to the legacy measures evaluated at nearly all time points.

BACKGROUND:In the past decade, the prevalence of end-stage inflammatory elbow arthritis has declined with consequential changes in indications and utilization of total elbow arthroplasty (TEA). Current literature lacks future projections for the utilization of TEA. The aim of this study is to review the trends in the utilization of TEA in the last 2 decades and determine the projections of utilization for TEA (primary and revision) through 2060. METHODS:This analysis used the publicly available 2000-2019 data from the CMS Medicare Part-B National Summary. Procedure volumes including TEA, and revision TEA, were determined using Current Procedural Terminology codes and were uplifted to account for the growing number of Medicare eligible patients covered under Medicare Advantage. Using these volumes, log-linear, Poisson, negative binomial regression, and autoregressive integrated moving average models were applied to generate projections from 2020 to 2060. The Poisson model was chosen to display the data based on error analysis and prior literature. RESULTS:The projected annual growth rates from 2020 to 2060 for primary and revision TEAs are 1.03% (95% confidence interval: 0.82%-1.25%) and 5.17% (95% confidence interval: 3.02%-6.97%), respectively. By 2060, the demand for primary TEA and revision TEA is projected to be 2084 procedures (95% forecast interval: 1995-2174) and 3161 procedures (95% forecast interval: 3052-3272), respectively. The procedure volume for revision TEA is estimated to outnumber primary TEA by year 2050. CONCLUSION/CONCLUSIONS:The overall procedural volume of primary TEA and revision TEA continues to be low. Although it is estimated that the incidence of primary and revision TEAs will continue to increase in the next 40 years, the utilization trends only show a mild increase, which is 5 times higher for revision TEA than primary TEA.

BACKGROUND:The purpose of this study was to define the optimal combination of surgical technique and postoperative rehabilitation protocol for elderly patients undergoing either hemiarthroplasty (HA) or reverse total shoulder arthroplasty (rTSA) for acute proximal humerus fracture (PHF) by performing a network meta-analysis of the comparative studies in the literature. METHODS:A systematic review of the literature using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines of MEDLINE, EMBASE, and Cochrane Library was screened from 2007 to 2023. Inclusion criteria were level I-IV studies utilizing primary HA and/or rTSA published in a peer-reviewed journal, that specified whether humeral stems were cemented or noncemented, specified postoperative rehabilitation protocol, and reported results of HA and/or rTSA performed for PHF. Early range of motion (ROM) was defined as the initiation of active ROM at ≤3 weeks after surgery. Level of evidence was evaluated based on the criteria by the Oxford Centre for Evidence-Based Medicine. Clinical outcomes were compared using a frequentist approach to network meta-analysis with a random-effects model that was performed using the netmeta package version 0.9-6 in R. RESULTS:A total of 28 studies (1119 patients) were included with an average age of 74 ± 3.7 and mean follow-up of 32 ± 11.1 months. In the early ROM cohort (Early), the mean time to active ROM was 2.4 ± 0.76 weeks compared to 5.9 ± 1.04 weeks in the delayed ROM cohort (Delayed). Overall, rTSA-Pressfit-Early resulted in statistically superior outcomes including postoperative forward elevation (126 ± 27.5), abduction (116 ± 30.6), internal rotation (5.27 ± 0.74, corresponding to L3-L1), American Shoulder and Elbow Surgeons score (71.8 ± 17), tuberosity union (89%), and lowest tuberosity nonunion rate (9.6%) in patients ≥65 year old with acute PHF undergoing shoulder arthroplasty (all P ≤ .05). In total there were 277 (14.5%) complications across the cohorts, of which 89/277 (34%) were in the HA-Cement-Delayed cohort. HA-Cement-Delayed resulted in 2-times higher odds of experiencing a complication when compared to rTSA-Cement-Delayed (P = .005). Conversely, rTSA-Cement-Early cohort followed by rTSA-Pressfit-Early resulted in a total complication rate of 4.7% and 5.4% (odds ratios, 0.30; P = .01 & odds ratios, 0.42; P = .05), respectively. The total rate of scapular notching was higher in the cemented rTSA subgroups (16.5%) vs. (8.91%) in the press fit rTSA subgroups (P = .02). CONCLUSION/CONCLUSIONS:Our study demonstrates that patients ≥65 years of age, who sustain a 3-or 4-part PHF achieve the most benefit in terms of ROM, postoperative functional outcomes, tuberosity union, and overall complication rate when undergoing rTSA with a noncemented stem and early postoperative ROM when compared to the mainstream preference-rTSA-Cement-Delayed.

INTRODUCTION/BACKGROUND:Superior augment use may help avoid superior tilt while minimizing removal of inferior glenoid bone. Therefore, our goal is to compare superior augments versus no augment baseplates in RSA for patients with rotator cuff dysfunction and no significant superior glenoid erosion. METHODS:A multicenter retrospective analysis of 145 patients who underwent RSA with intraoperative navigation (Exactech, Equinoxe GPS) and three-year follow-up (mean 32-month follow-up, range 20 to 61 months) who had preoperative superior inclination less than 10 degrees and retroversion less than 15 degrees. Patient demographics, radiographic measurements, surgical characteristics, patient-reported outcomes at preoperative and postoperative visit closest to three years, and adverse events at final follow-up were obtained. Operative time, planned inclination, and planned version of the baseplate were obtained. Chi-square test used to compare categorical variables and student t-test used to compare augment and no augment cohorts. RESULTS:The study population consisted of 54 superior augment patients and 91 no augment patients. The augment cohort had lower BMI (27.2 vs. 29.4, p-0.023), higher native superior inclination (5.9 vs. 1.4 degrees, p<0.001). No difference between the augment and no augment cohorts was found regarding age (p=0.643), gender (p=0.314), medical comorbidities (p>0.05), surgical indication (p=0.082), and native glenoid version (p=0.564). The augment cohort had higher internal rotation score (4.6 vs. 3.9, p=0.023), all remaining ROM and PROs preoperatively were not significantly different. At final follow-up, active ROM in all planes was not different between the cohorts. Regarding PROs, the postoperative SAS score was significantly higher (78.0 vs. 73.6, p=0.042), and ASES score trended towards higher (83.6 vs. 77.5, p=0.063) in the augment cohort. The augment cohort had significantly lower proportion of patients planned to have superior baseplate tilt (1.9% vs. 14.3%, p=0.012), and had greater mean inclination correction (6.3 vs. 1.3 degrees, p<0.001), compared to no augment cohort. Adverse events were rare, and there was no significant difference found between the augment and no augment cohorts (5.6% vs. 3.3%, p=0.509). DISCUSSION/CONCLUSIONS:Superior augmented baseplate in RSA with minimal superior glenoid erosion is associated with similar ROM and adverse events with somewhat improved postoperative PROs compared to non-augmented baseplates at 3-year follow-up. Additionally, superior augments resulted in a greater proportion of baseplates planned to avoid superior tilt, and trended toward shorter operative times. Further investigation of long-term glenoid baseplate loosening is imperative to fully understand the cost-effectiveness of superior augments in the setting of minimal glenoid deformity.

BACKGROUND:Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. METHODS:A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. RESULTS:A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. CONCLUSION/CONCLUSIONS:MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

BACKGROUND:The design of reverse shoulder arthroplasty (RSA) implants has evolved significantly over the past 50 years. Today there are many options available that differ in design of the glenoid and humeral components, fixation methods, sizes, and modularity. With respect to the humeral component, the literature has generally focused on the differences between inlay and onlay designs and the potential impact on outcomes. However, inlay and onlay design represents only one factor of many. METHODS:It is our hypothesis that separating onlay and inlay designs into 2 distinct entities is an oversimplification as there can be a wide overlap of the 2 designs, depending on surgical technique and the implant selected. As such, the differences between inlay and onlay designs should be measured in absolute terms-meaning combined distalization and lateralization. RESULTS:By reviewing the many factors that can contribute to the glenosphere-humerus relationship, the role of inlay and onlay humeral designs as an important distinguishing feature is shown to be limited. Preliminary studies suggest that the amount of distalization and lateralization of the construct may be the most accurate method of describing the differences in the constructs. CONCLUSIONS:Inlay and onlay humeral component design represents only one factor of many that may impact outcomes. A more accurate method of defining specific design and technique factors in RSA is the degree of lateralization and distalization.

INTRODUCTION/BACKGROUND:The aim of this study is 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 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 multi-center 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 dataset by multiple risk factor combinations and calculated the odds ratio for each cohort to quantify the impact of accumulating risk factors on dislocation. RESULTS:136 (52F/83M/1UNK) of 10,023 primary rTSA patients 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 (1,268 of 10,023) had no risk factors, and only 0.5% of these (6 of 1,268) 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/CONCLUSIONS:This 10,023 rTSA multi-center study demonstrated that 1.4% of rTSA 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 incidence of dislocation. rTSA patients with the greatest risk of dislocation were: male gender, age ≤67 years at the time of surgery, patients with BMI ≥31, patients who received cemented humeral stems, patients who received glenospheres having a diameter >40mm, and/or patients who received expanded/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.