Publications

BACKGROUND: Previous literature has demonstrated that an increased number of preoperative anterior shoulder instability episodes is associated with recurrent anterior shoulder instability after arthroscopic Bankart repair (ABR). However, a threshold for the number of preoperative instability episodes that increases the risk of recurrent anterior shoulder instability is not well established.

PURPOSE: To establish a threshold value for the number of preoperative instability episodes that predicts recurrent anterior shoulder instability after ABR and to compare glenoid bone loss, the Hill-Sachs interval, and the distance to dislocation between patients who have surpassed the threshold and those who have not.

STUDY DESIGN: Retrospective cohort study; Level of evidence, 3.

METHODS: This retrospective review included consecutive patients with "on-track" Hill-Sachs lesions who underwent primary ABR for anterior shoulder instability at a single institution between 2007 and 2019. Patients with an unknown number of preoperative instability episodes, >20% glenoid bone loss, <2 years' follow-up, or age >40 or <14 years were excluded. Logistic regression assessed associations between preoperative anterior shoulder instability episodes and recurrent anterior shoulder instability after ABR, defined as a recurrent subluxation or dislocation. Receiver operating characteristic analysis determined the optimal threshold of preoperative anterior shoulder instability episodes to predict recurrent anterior shoulder instability. Significance was set as P < .050.

RESULTS: A total of 151 patients (mean age, 20 ± 5 years; mean follow-up, 6.0 ± 3.1 years) were included, of whom 28 (19%) experienced recurrent anterior shoulder instability. Multiple thresholds showed increased odds of recurrent anterior shoulder instability: ≥2 preoperative anterior shoulder instability events (odds ratio [OR], 9.70 [95% CI, 2.63-35.70]; P = .001), ≥3 events (OR, 3.47 [95% CI, 1.37-8.80]; P = .009), and ≥4 events (OR, 3.08 [95% CI, 1.17-8.08]; P = .023). Receiver operating characteristic analysis revealed that ≥2 preoperative anterior shoulder instability events was the strongest predictor of recurrent anterior shoulder instability (area under the curve = 0.72).

CONCLUSION: A threshold of ≥2 preoperative anterior shoulder instability episodes best predicted recurrent anterior shoulder instability after ABR. Stratification beyond 1 versus ≥2 preoperative anterior shoulder instability episodes did not increase predictive ability. This finding may help surgeons to counsel patients and consider earlier surgical stabilization in those who have sustained anterior shoulder instability episodes.

BACKGROUND: Nonoperative management of atraumatic rotator cuff tears often includes corticosteroid injection (CSI). Concerns persist regarding CSI effect on tendon quality and rotator cuff repair (RCR) outcomes, though how timing of a single CSI influences RCR outcomes is unclear. This study evaluated whether CSI timing within 1 year before RCR affects repair failure, patient-reported outcomes (PROs), range of motion (ROM), and strength, compared to patients undergoing RCR without CSI. We hypothesized that CSI within 3 months of RCR would lead to higher failure rates and worse outcomes.

METHODS: This retrospective study examined consecutive adult patients undergoing primary RCR from 2015 to 2022 at 1 institution. Inclusion criteria were nonoperative management of an atraumatic rotator cuff tear ≥6 weeks and minimum 1-year follow-up. Exclusion criteria included prior shoulder surgery and traumatic injury. Patients with preoperative CSI were grouped by CSI timing before RCR: <3 months, 3-6 months, and 6 months-1 year. Primary outcome was repair failure (reoperation or magnetic resonance imaging-confirmed retear). Magnetic resonance imaging was performed only in patients with symptoms suggesting recurrent cuff pathology. Secondary outcomes included PROs (Subjective Shoulder Value, Patient-Reported Outcomes Measurement Information System scores, American Shoulder and Elbow Surgeons score, visual analog scale [VAS]), strength, and ROM.

RESULTS: Overall, 198 patients were included; 89 patients without preoperative CSI (controls), 44 with CSI within 3 preoperative months, 34 with CSI 3-6 months prior, and 31 with CSI 6-12 months prior. Mean ages were 59 (controls), 59 (CSI <3 months), 63 (CSI 3-6 months), and 57 years (CSI 6-12 months) (P = .13). Demographics, follow-up length, RCR technique, and tendons involved were comparable across groups (all P > .05). Overall repair failure was 24%, with 19% failure in patients who received CSI. Group failure rates were 30% (controls), 20% (<3 months), 18% (3-6 months), and 19% (6 months-1 year) (P = .34). Postoperative improvements were similar between all groups for visual analog scale (3 vs. 4 points, P > .05), Subjective Shoulder Value (21% vs. 29%, P > .05), and American Shoulder and Elbow Surgeons scores (15 vs. 12 points, P > .05). Postoperative external rotation decreased by 4° among all CSI patients (P = .02) but increased by 3° in controls. Postoperative PROs, ROM, and strength were similar between groups.

CONCLUSION: This study demonstrated comparable outcomes for patients receiving CSI within 1 year of RCR and control patients. Timing of 1 preoperative CSI within 1 year of RCR did not significantly affect failure, PROs, ROM, or strength, suggesting that 1 CSI before RCR does not strongly influence outcomes.

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.

BACKGROUND: Recent literature has shown that inferior Hill-Sachs extension for on-track shoulders is predictive of recurrent instability after arthroscopic Bankart repair alone. Specifically, there is a high risk for recurrent instability when the lesion extends below the humeral equator on sagittal magnetic resonance imaging. This worrisome inferior extension has been termed "critical humeral bone loss (CHBL)." Remplissage has yet to be explored as a potential useful augmentation in patients with CHBL.

HYPOTHESIS: The addition of remplissage would decrease recurrence rates for Hill-Sachs lesions with inferior extension or CHBL compared with arthroscopic Bankart repair alone in patients with on-track Hill-Sachs lesions.

STUDY DESIGN: Case series; Level of evidence, 4Methods:Retrospective analysis was performed on the records of patients who underwent primary arthroscopic Bankart repair with or without the addition of remplissage from 2007 to 2021. Off-track shoulders, revision stabilization, glenoid bone loss (GBL) >20%, and those with follow-up <2 years or incomplete medical data were excluded. The primary outcome was recurrent instability, defined as either postoperative dislocation or subluxation. The Hill-Sachs position was measured relative to the humeral axis on sagittal magnetic resonance imaging as previously described. Univariate and multivariate logistic regression analyses were implemented to determine the protective effect of remplissage.

RESULTS: A total of 219 patients were included for analysis with a mean age of 21.1 years (range, 12.9-40.5 years) and mean follow-up of 7.0 years (range, 2-14.4 years); 44 patients (20%) underwent remplissage in addition to arthroscopic Bankart. In multivariate analysis, remplissage significantly reduced the risk of recurrent instability (OR, 0.06; P = .002) and CHBL was a significant predictor of recurrent instability (OR, 3.0; P = .029) while adjusting for age, multiple preoperative dislocations, contact athlete status, and percent GBL. When stratified by CHBL, remplissage remained protective (OR, 0.013; P = .007) against recurrent instability.

CONCLUSION: The addition of a remplissage for CHBL in patients with subcritical GBL and on-track Hill-Sachs lesions reduces the risk of recurrent instability in patients undergoing arthroscopic Bankart repair.

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.

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.

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.

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.