Publications

BACKGROUND: Glenoid bone grafting procedures are often utilized to address glenoid bone loss in patients with recurrent shoulder instability. The purpose of this study was to determine if preoperative advanced imaging can accurately predict coracoid graft size and conversion of off-track to on-track Hill-Sachs lesions in patients undergoing Latarjet procedures.

METHODS: Patients who underwent Latarjet procedure for shoulder instability at a single institution from 2012 to 2020 with preoperative and postoperative advanced shoulder imaging (computerized tomography or magnetic resonance imaging scans) were retrospectively reviewed. Glenoid diameter, Hill-Sachs interval (HSI), and measurements of the coracoid length, depth, and height were measured on preoperative imaging. Glenoid track (GT), percent glenoid bone loss, predicted restoration of GT, and the difference between HSI and GT (ΔHSI-GT) were calculated.

RESULTS: Seventeen patients with a mean age of 25 ± 9 years met inclusion criteria. Average glenoid bone loss preoperatively was 24 ± 7% and average HSI was 27 ± 5mm. The Latarjet procedure reconstructed 116 ± 8% of the native glenoid, and 104 ± 8% of the predicted diameter. Of the 15 patients that had off-track lesions preoperatively, 11 were successfully converted to on-track lesions (73%). The 4 persistent off-track lesions had a significantly higher HSI (32 ± 2 mm vs. 26 ± 4 mm, P = .002). Preoperative measurements accurately predicted postoperative GT status in 94% of cases. At a mean follow-up of 2 years, there was no significant difference in recurrence rate or rate of revision stabilization procedures between patients with on-track versus persistent off-track humeral lesions.

CONCLUSION: Preoperative advanced imaging measurements can accurately predict whether an off-track Hill-Sachs can be converted to on-track after Latarjet procedure, further enhancing shoulder stability.

Internal rotation (IR) is not reliably improved after reverse shoulder arthroplasty (RSA). This study aimed to identify surgical parameters that predict kinematics of the hand-to-back motion (H2B) after RSA and to identify associations between kinematics and clinical outcomes after RSA. We hypothesized that less humeral retroversion, more lateralization and a larger glenosphere would predict kinematics associated with favorable outcomes post-RSA. Thirty-five patients performed H2B while synchronized biplane radiographs were collected. Digitally reconstructed radiographs, constructed from patient-specific bone plus implant models, were matched to the biplane radiographs to determine kinematics. The total contribution to motion, the end position, peak angles, and range of motion (ROM) were found for all glenohumeral and scapular rotations. The path of the center of the humeral insert on the glenosphere was calculated. Patient-reported outcomes, clinical ROM, and strength were measured. Associations were determined between intraoperative variables and kinematics as well as between kinematics and outcomes. The results demonstrated that glenosphere tilt predicted glenohumeral and scapular kinematics; these kinematics were associated with IR ROM, strength, and more favorable patient-reported outcomes. A larger glenosphere predicted a center of contact that was associated with more strength in IR. All components of scapular rotation were associated with favorable outcomes, suggesting rehabilitation focusing on scapular motion may improve outcomes post-RSA. Glenosphere tilt and size predicted kinematics that were associated with range of motion, strength, and patient-reported outcomes.

The purpose of this study was to identify surgical techniques and implant geometries that influence in-vivo kinematics, functional outcomes, and clinical outcomes after reverse shoulder arthroplasty (RSA). Synchronized biplane radiographs imaged the operated shoulder during scapular plane abduction in 35 patients who received RSA within the past 2.5 ± 1.2 yrs. Shoulder kinematics and arthrokinematics (contact paths) were determined by matching subject-specific CT-based bone-plus-implant models to the radiographs using a validated tracking technique. Torque and total work done during abduction were measured using an isokinetic dynamometer. Implant characteristics and surgical techniques that were associated with kinematics/arthrokinematics, strength, or patient-reported outcomes were identified using multiple linear regression. Neck shaft angle, glenosphere size, and retroversion were associated with in-vivo kinematics and functional outcomes during abduction after RSA. These findings improve our understanding of how implant design and surgical technique impact kinematics and functional outcomes after RSA. The results highlight the necessity of in vivo data to validate cadaver-based research and computer simulations of joint function after RSA, emphasizing that those models do not account for the dynamic healing process and neuromuscular adaptations that occur after surgery.

BACKGROUND: The amount of glenoid bone loss (GBL) in anterior shoulder instability helps determine management options. Unfortunately, there is no consensus on how to accurately measure GBL.

HYPOTHESIS: The best-fit circle missing area method has better accuracy and interrater reliability than the ratio and diameter methods.

STUDY DESIGN: Controlled laboratory study.

METHODS: Three-dimensional computed tomography shoulder scans were collected and segmented on 4 healthy male participants (mean age, 22.5 ± 3.4 years). For each scapula, 5 GBL models were created with known levels of GBL (5%-30%) in the anteroinferior glenoid rim. Ground-truth GBL was determined using the glenoid fossa edge and best-fit circle of the anteroinferior edge. Six blinded reviewers with varying expertise measured GBL for 20 randomized models using 3 different best-fit circle methods (missing area, ratio, and diameter). Accuracy was assessed by root mean square error and obtained by comparing measured and ground truth for bone loss for each model. Interrater reliability was assessed using intraclass correlation coefficients (ICCs) with a 2-way random-effects model with consistency.

RESULTS: On average, the missing area method overestimated GBL by 1%, while the ratio method and diameter method overestimated GBL by 2.4% and 6.3%, respectively. The interrater reliabilities of the missing area (ICC, 0.89), ratio (ICC, 0.91), and diameter (ICC, 0.90) methods were good, excellent, and good, respectively. For all reviewers, the overall root mean square error of the missing area method (3.6%) was better than that of the ratio (5%) and diameter (7.9%) methods. When stratifying reviewer accuracy by level of training, the missing area method remained superior at all levels when compared with the ratio and diameter methods (attending [3.1% vs 3.8% and 8.9%], fellow [4.2% vs 6.3% and 8.4%], and resident [3.5% vs 4.6% and 6.3%]).

CONCLUSION: The best-fit circle missing area method was reliable and more accurate at measuring GBL than the other methods. This held true at all levels of surgical experience (resident, fellow, and attending).

CLINICAL RELEVANCE: The best-fit circle missing area method is accurate, has good reliability, and is simple. This can enhance preoperative planning for shoulder surgeons.

PURPOSE: This study aimed to identify surgical parameters during reverse shoulder arthroplasty (RSA) that predict post-surgical kinematics during the hand-to-head motion (H2H) and to identify associations between kinematics and outcomes. We hypothesized that greater humeral retroversion and lateralization predict kinematics, and that more scapular upward rotation is associated with better PROs and more range of motion (ROM).

METHODS: Thirty-five post-RSA patients consented to participate. All surgical parameters were recorded while operating or measured on CT. Participants performed H2H while synchronized biplane radiographs were collected at 50 images/second. Digitally reconstructed radiographs were matched to biplane radiographs to determine glenohumeral and scapular kinematics. For all rotations, the contribution, end position, peak angles, and ROM were calculated. Contact path between the glenosphere and polyethylene insert was calculated. Patient-reported outcomes (PROs), clinical ROM, and strength were measured. Multiple linear regression identified surgical parameters that predicted kinematics, and Pearson correlation identified associations between kinematics and outcomes.

RESULTS: Less humeral retroversion predicted greater peak abduction (p = 0.035). Humeral neck-shaft angle, retroversion, and glenoid tilt predicted the peak posterior contact path (p = 0.012). Better PROs were associated with more superior contact path (p < 0.001), more abduction (p < 0.001), and greater peak scapular upward rotation (p = 0.017). Greater strength was correlated with more peak external rotation (p = 0.035). Greater external rotation at 90º was associated with more abduction (p = 0.008) and upward scapula rotation ROM (p = 0.015) during H2H.

CONCLUSION: Less humeral retroversion predicted kinematics during H2H that were associated with more favorable PROs and clinical outcomes.

BACKGROUND: Glenoid bone grafting procedures are often utilized to address glenoid bone loss in patients with recurrent shoulder instability. The purpose of this study was to determine if preoperative advanced imaging can accurately predict coracoid graft size and conversion of off-track to on-track Hill-Sachs lesions in patients undergoing Latarjet procedures.

METHODS: Patients who underwent Latarjet procedure for shoulder instability at a single institution from 2012 to 2020 with preoperative and postoperative advanced shoulder imaging (computerized tomography or magnetic resonance imaging scans) were retrospectively reviewed. Glenoid diameter, Hill-Sachs interval (HSI), and measurements of the coracoid length, depth, and height were measured on preoperative imaging. Glenoid track (GT), percent glenoid bone loss, predicted restoration of GT, and the difference between HSI and GT (ΔHSI-GT) were calculated.

RESULTS: Seventeen patients with a mean age of 25 ± 9 years met inclusion criteria. Average glenoid bone loss preoperatively was 24 ± 7% and average HSI was 27 ± 5mm. The Latarjet procedure reconstructed 116 ± 8% of the native glenoid, and 104 ± 8% of the predicted diameter. Of the 15 patients that had off-track lesions preoperatively, 11 were successfully converted to on-track lesions (73%). The 4 persistent off-track lesions had a significantly higher HSI (32 ± 2 mm vs. 26 ± 4 mm, P = .002). Preoperative measurements accurately predicted postoperative GT status in 94% of cases. At a mean follow-up of 2 years, there was no significant difference in recurrence rate or rate of revision stabilization procedures between patients with on-track versus persistent off-track humeral lesions.

CONCLUSION: Preoperative advanced imaging measurements can accurately predict whether an off-track Hill-Sachs can be converted to on-track after Latarjet procedure, further enhancing shoulder stability.

BACKGROUND: With increasing efforts to transition shoulder arthroplasty to the ambulatory surgery setting, there is increased interest in predictive factors of failure of same-day discharge (SDD). The purpose of this study was to identify predictors of failing SDD, defined as requiring at least an overnight hospital stay after shoulder arthroplasty, and to develop a predictive model to identify which patients may require postoperative hospital admission.

METHODS: A retrospective review of a consecutive series of patients with rotator cuff arthropathy or osteoarthritis treated with primary anatomic or reverse total shoulder arthroplasty between January 2019 and June 2023 was conducted. Inclusion criteria included patients intended for SDD, whereas patients who underwent arthroplasty for fractures, patients younger than 45 years, and patients with incomplete data were excluded. Data on demographics, Charlson Comorbidity Index, preoperative opioid use, and preoperative steroid injections were collected. In addition, intraoperative metrics including American Society of Anesthesiologists score, surgical/anesthesia time, surgical start time, and blood loss were recorded. Multivariate logistic regression was used to identify predictors of failure of SDD. Results were displayed as odds ratios (OR) and 95% confidence intervals. The α threshold was set to P < .05.

RESULTS: A total of 333 patients (69 anatomic total shoulder arthroplasty and 264 reverse total shoulder arthroplasty) were included with 92 failures of SDD (27.6%). According to multivariate results, we found older age (OR: 1.44, P = .004), anesthesia start time per hour later in the day (OR: 6.03, P = .017), preoperative opioid use within the past year (OR: 1.82, P = .046), and female sex (OR: 2.76, P = .001) as statistically significant risk factors for not achieving SDD. In addition, each half-hour increase in length of time under anesthesia was statistically significant, increasing odds of failing SSD by 4.28 per half hour (P < .001). A diagnosis of rotator cuff arthropathy had 3.40 greater odds of failing to achieve SDD as compared with a diagnosis of osteoarthritis (P < .001). Overall, the model had a high level of predictability, yielding a receiver operating characteristic curve area under the curve of 83%.

CONCLUSIONS: Older age, rotator cuff arthropathy, female sex, preoperative opioid use, and prolonged anesthesia exposure were significant predictors of failure of SDD after shoulder arthroplasty. These results support the utility in risk stratification strategies of patients to accurately triage them into SDD pathways. In addition, our results suggested that collaboration between surgeons and anesthesia teams may allow for more accurate risk stratification and optimization of resource utilization when deciding which patients are appropriate candidates for SDD.

PURPOSE: To evaluate rates of recurrent anterior glenohumeral instability among patients with "on-track" Hill-Sachs lesions who underwent either arthroscopic Bankart repair (ABR) alone or arthroscopic Bankart repair with remplissage augmentation (ABR+R) and develop a risk assessment tool for recurrent anterior glenohumeral instability as well as evaluate the role of remplissage augmentation for on-track shoulders to predict outcomes after arthroscopic stabilization.

METHODS: We retrospectively reviewed prospectively collected data of patients aged 14 to 40 years who underwent ABR or ABR+R between 2013 and 2021. Chart review was performed to gather patient-specific risk factors such as patient age, gender, sport-specific participation, number of preoperative dislocations, and shoulder laxity, whereas imaging measurements were used to gather glenoid bone loss and distance-to-dislocation. Recurrent anterior glenohumeral instability was defined as recurrent dislocation and/or subjective subluxation postoperatively. Exclusion criteria included revision procedure, less than 2-year follow-up, presence of an "off-track" Hill-Sachs lesion, documented connective tissue disorder, concomitant rotator cuff tear, missing data, or the presence of glenoid bone loss >20%. Multivariate hazard ratio estimates were used to create a risk assessment tool and correlated with patient-specific risk via postestimation analysis.

RESULTS: A total of 170 patients were included for analysis (ABR: 116, ABR+R: 54) with an average age of 21.5 ± 6.2 years and an average follow-up of 5.1 years (2.0-9.0 years). Near-track lesions ("on-track" lesions with a distance-to-dislocation value less than 10 mm), presence of hyperlaxity, younger age, 2+ preoperative recurrent instability episodes, contact sport athlete status, and increasing glenoid bone loss were independent risk factors for ABR failure on the basis of a final multivariate model predicting postoperative failure. Furthermore, patients undergoing ABR alone had a greater risk of recurrent instability than those undergoing ABR+R. From the final multivariate model using these prognostic factors, the hazard ratios were used to create the Pittsburgh Instability Tool (PIT) and was subsequently used to create risk-stratifying subgroups: low-risk (0-3), moderate-risk (4-8), high-risk (9-13), extreme-risk (14+). Remplissage augmentation lowered the PIT score by 8 points. Recurrent instability rates range from 2.2% among low-risk groups to 51.3% among extreme-risk groups.

CONCLUSIONS: The current study indicates that arthroscopic Bankart repair with remplissage augmentation can lower the rate of recurrent instability in patients with high-risk "on-track" lesions. Surgeons can use the PIT tool to identify suitable candidates who may or may not benefit from arthroscopic Bankart repair with or without remplissage augmentation by computing PIT scores for both scenarios. However, if patient risk remains elevated with or without remplissage augmentation, these individuals may not benefit solely from arthroscopic soft-tissue stabilization. The PIT risk assessment tool is a valuable resource for surgeons in evaluating the recurrence risks associated with remplissage augmentation, thus optimizing surgical strategies for on-track lesions with less than 20% glenoid bone loss.

LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Internal rotation (IR) is not reliably improved after reverse shoulder arthroplasty (RSA). This study aimed to identify surgical parameters that predict kinematics of the hand-to-back motion (H2B) after RSA and to identify associations between kinematics and clinical outcomes after RSA. We hypothesized that less humeral retroversion, more lateralization and a larger glenosphere would predict kinematics associated with favorable outcomes post-RSA. Thirty-five patients performed H2B while synchronized biplane radiographs were collected. Digitally reconstructed radiographs, constructed from patient-specific bone plus implant models, were matched to the biplane radiographs to determine kinematics. The total contribution to motion, the end position, peak angles, and range of motion (ROM) were found for all glenohumeral and scapular rotations. The path of the center of the humeral insert on the glenosphere was calculated. Patient-reported outcomes, clinical ROM, and strength were measured. Associations were determined between intraoperative variables and kinematics as well as between kinematics and outcomes. The results demonstrated that glenosphere tilt predicted glenohumeral and scapular kinematics; these kinematics were associated with IR ROM, strength, and more favorable patient-reported outcomes. A larger glenosphere predicted a center of contact that was associated with more strength in IR. All components of scapular rotation were associated with favorable outcomes, suggesting rehabilitation focusing on scapular motion may improve outcomes post-RSA. Glenosphere tilt and size predicted kinematics that were associated with range of motion, strength, and patient-reported outcomes.