Journal of Shoulder and Elbow Surgery最新文献

Background: Elbow valgus stability relies on both static and dynamic stabilizers. The medial collateral ligament (MCL), particularly the anterior bundle (AB), provides primary resistance to valgus stress, whereas the flexor-pronator mass (FPM) offers secondary, dynamic support. Combined disruption of these structures-especially following trauma-can result in significant elbow instability. This cadaveric study aimed to quantify radiographic changes in the medial ulnohumeral joint (UHJ) space and valgus alignment following sequential transection of the AB, posterior bundle (PB), and FPM.

Methods: Twelve cadaveric elbows were sequentially tested after sequential transection of the AB, PB, and FPM. Radiographs were obtained at 60° of flexion under standardized valgus stress. Changes in mean medial UHJ space and α-angle were compared across stages using the Friedman test with Wilcoxon post-hoc analysis (p < 0.05).

Results: The mean specimen age was 63 years (70% male). Mean medial UHJ space increased progressively from 5.4 ± 1.1 mm in the intact state to 12.4 ± 3.0 mm after AB transection, 16.1 ± 3.9 mm after combined AB + PB transection, and 26.4 ± 7.8 mm after additional FPM release. Correspondingly, mean α-angle rose from 2.8° ± 1.7° to 3.4° ± 3.0°, 5.0° ± 4.2°, and 13.6° ± 8.6°, respectively. All comparisons were statistically significant (p < 0.001).

Conclusion: In this cadaveric model, UHJ opening ≈15 mm suggested full MCL disruption, and >20 mm or α-angle ≈13° indicated additional FPM compromise; these values are experimental reference ranges for medial soft tissue injuries.

Background: The treatment of large to massive rotator cuff tears leads to a high failure rate and several techniques have been proposed to improve these results. Rerouting the long head of the biceps tendon (LHBT) appears to be a biological reinforcement to increase tendon healing. Therefore, this study aimed to compare the clinical and radiological outcomes of open repair for large and massive rotator cuff tears reinforced with the LHBT to conventional open repair.

Methods: A prospective randomized study was conducted with patients diagnosed with large to massive rotator posterosuperior rotator cuff tear and intact LHBT, randomized into two groups: biceps rerouting and conventional open repair. The functional outcomes were assessed by the American Shoulder and Elbow Surgeon (ASES) score, University of California at Los Angeles (UCLA) score and SF-12 questionnaire preoperatively and at 6, 12, and 24 months postoperatively. Pain level was also assessed by the visual analog scale (VAS) including the first day and 2 weeks postoperatively. Structural outcomes were rotator cuff and LHBT healing with magnetic resonance imaging (MRI) and acromiohumeral distance (AHD) through radiography.

Results: We evaluated 58 patients, 29 in each group. At the end of the follow-up there were no statistically significant differences between groups in ASES (76.1 vs 80.4, p=0.761), UCLA (27.1 vs 29.1, p=0.634), or VAS scores (1.3 vs 1.1, p=0.781). Additionally, rotator cuff healing rates (48.3% vs 44.8%, p=0.402) and LHBT healing rates (79.3% vs 82.7%, p=0.738) were similar. AHD increased in both groups, with no significant difference in delta AHD (p=0.513). Both groups showed significant clinical improvement over time in all evaluated outcomes (p<0,001). No postoperative complications were reported.

Conclusions: We could not identify an advantage of open repair with LHBT rerouting as reinforcement over conventional open repair. Nonetheless, all clinical scores improved at the end of the 24 months of follow-up in both groups.

Background: Proximal humeral fractures (PHF) are common in the elderly population, and the use of reverse total shoulder arthroplasty (rTSA) as treatment has risen substantially in recent years. As opposed to statistical significance, clinical value has increasingly been utilized to evaluate outcomes, thus this study aims to define patient acceptable symptom state (PASS) thresholds, minimal clinically important differences (MCID), and substantial clinical benefit (SCB) values for American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score (CMS), and Shoulder Arthroplasty Smart (SAS) score in patients undergoing rTSA for PHFs.

Methods: A prospectively collected multicenter database inclusive of 43 clinical sites using Advita Ortho implant system was queried for patients receiving who underwent reverse total shoulder arthroplasty for proximal humeral fracture with a minimum of 2 years follow-up between 2007 and 2024. Patients were divided into Early (no prior ORIF, malunion, or nonunion) and Late (history of ORIF, malunion, or nonunion) treatment groups. Prospectively, outcome metrics including preoperative and postoperative CMS, ASES score, SAS score, active range of motion, visual analog scale (VAS) pain scores, self-reported shoulder function score, and patient satisfaction rate were collected from the electronic medical record. Receiver operating characteristic (ROC) curve analysis was used to determine the PASS thresholds while MCID and SCB values were determined via anchor-based methods and distribution-based methods, respectively.

Results: PASS thresholds were numerically higher in the Late group across all measures. Postoperative ASES, CMS, and SAS scores all showed good discriminative ability for identifying patients who achieved PASS. Optimal PASS thresholds were 58 (AUC = 0.73) and 60 (AUC = 0.80) for ASES, 62 (AUC = 0.65) and 66 (AUC = 0.77) for CMS, and 61 (AUC = 0.74) and 67. (AUC = 0.85) for SAS in the Early and Late groups, respectively. Anchor-based MCID values were slightly lower in the Late group, suggesting that a smaller score change was needed for perceived improvement by patients (ASES: 10.84 and 10.31; CMS: 9.59 and 8.54; SAS: 10.75 and 7.60). Distribution-based SCB thresholds were observed to have higher values in the Early group, indicating that patients treated earlier required greater functional improvement to perceive substantial benefit (ASES: 17.35 and 16.49; CMS: 15.35 and 13.67; SAS: 17.19 and 12.16).

Conclusion: In patients undergoing reverse total shoulder arthroplasty for proximal humeral fracture, PASS thresholds for ASES, CMS, and SAS demonstrate good discriminative ability for identifying clinically meaningful improvement. Thresholds are reported separately for Early and Late treatment cohorts and should be interpreted as descriptive benchmarks.

Introduction: The utility and optimal threshold for serum laboratory tests taken prior to revision shoulder arthroplasty are unknown. We performed a multi-institutional study of consecutive revision shoulder arthroplasties to define the optimal thresholds of serum laboratory samples to predict bacterial presence in intraoperative cultures with and without Definite Periprosthetic Joint Infection (PJI).

Methods: Multicenter data was collected on 579 revision shoulder arthroplasties. Preoperative serum erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), complete blood count differentials, and ratios were reported. Analysis was stratified based on International Consensus Meeting (ICM) Definite and Non-Definite PJI and two different thresholds of culture positivity (≥2 or ≥3). Receiver operating characteristic (ROC) curves were constructed, and area under the curve (AUC), optimal thresholds, and diagnostic utility for each test were calculated.

Results: Eighty-three patients (14%) had Definite PJI per ICM criteria while 496 (86%) had Non-Definite PJI. Cutibacterium was the most common bacteria recovered in both Definite PJI and Non-Definite PJI. For Definite PJI using a threshold of ≥3 positive cultures, AUC values were 0.543 for ESR and 0.659 for CRP. Optimal thresholds based on ROC curves were 50.5 mm/hr for ESR and 5.9 mg/L for CRP. Sensitivity and specificity were 0.422 and 0.714, respectively, for ESR and 0.818 and 0.536, respectively, for CRP. For Non-Definite PJI, the AUC value was below 0.5 for ESR indicating the test was worse than chance. AUC values for CRP were 0.533 and 0.540 using thresholds of ≥2 and ≥3 positive cultures, respectively. Optimal threshold based on ROC curves were 9.1.

Conclusion: This is the first large-scale, multicenter study of consecutive revision shoulder arthroplasties analyzing the utility of preoperative serum laboratory values in predicting positive intraoperative cultures. Overall diagnostic utility of these tests in predicting bacterial presence is low in the setting of both Definite and Non-Definite PJI, particularly serum ESR. In approaching patients with more obvious clinical symptoms (Definite PJI), optimal cutoff values are 50 mm/hr for ESR and 10 mg/L for CRP. When approaching workup of a patient without obvious signs of infection (Non-Definite PJI), serum ESR and CRP have limited value in predicting presence of bacteria at the time of revision arthroplasty.

Introduction: Optimizing patient outcomes in reverse total shoulder arthroplasty remains a subject of ongoing research. Newly described radiographic angles allow the determination of the glenoid and humeral component contributions to lateralization and distalization, which might play a role in patient outcomes. Thus, this study aims to explore the effect of radiographically measured glenoid versus humeral lateralization and distalization on patient reported outcomes and reoperation.

Methods: 217 consecutive patients who underwent rTSA from November 2016 to August 2022 were retrospectively reviewed. Pre-operative and final follow-up subjective shoulder value (SSV), visual analogue scale for pain (VAS), and American Shoulder and Elbow Surgeons Score (ASES), and unplanned reoperations were recorded. Preoperative and postoperative Lateralization Shoulder Angle (LSA) and Distalization Shoulder Angle (DSA) were also recorded. Postoperative Glenoid Lateralization Angle (GLA), Humeral Lateralization Angle (HLA), modified Distalization Shoulder Angle (mDSA), Glenoid Distalization Angle (GDA), and Humeral Distalization Angle (HDA). Correlations between different pairings of radiographic angular measurements were calculated along with correlations between individual radiographic measurements and each patient reported outcome measure.

Results: Greater positive change from preoperative to postoperative LSA and smaller postoperative DSA were significantly correlated with improved SSV in both univariable and multivariable analysis. A larger decrease from preoperative to postoperative LSA was associated with higher odds of reporting VAS > 0 on univariable analysis at follow up. Otherwise, there were no associations between radiographic measurements and postoperative outcome scores. The strongest correlation for postoperative lateralization measurements was between LSA and HLA (r = +0.83) and for postoperative distalization measurements was between mDSA and GDA (r = +0.72). Greater postoperative LSA and HLA values had higher odds of reoperation (post LSA OR = 1.11; p = 0.011, post HLA OR = 1.10; p = 0.047).

Conclusions: Greater positive change from preoperative to postoperative LSA was associated with improved subjective-shoulder value scores. Lower global distalization was associated with greater subjective-shoulder value scores. While global lateralization may be beneficial in moderation along with limiting global distalization, the independent effects of glenoid or humeral-sided lateralization or distalization measured radiographically may have a lesser impact on patient reported outcomes.

This narrative review presents commonly used radiographic parameters in shoulder surgery. The review outlines the historical context, definitions, and evidence regarding diagnostic and prognostic utility of each measurement. Limitations such as variability in imaging technique and lack of standardized measurement protocols are discussed. Despite these constraints, these measurements remain central to evaluating imaging of the shoulder, guiding implant positioning, assessing pathology, and comparing outcomes across studies.

Background: Determining which posterolateral elbow dislocations require surgery is challenging as major ligament tears often occur regardless of clinical stability. This study aimed to identify specific MRI patterns that represent the functional threshold for persistent mechanical instability.

Methods: We retrospectively reviewed MRIs of 186 elbows following acute posterolateral dislocation. The unstable group (n=24, 12.9%) showed gross mechanical instability or redislocation. We evaluated single-structure effects and a "Core-4" model comprising the flexor-pronator mass (FPM), posterior medial collateral ligament (pMCL), common extensor origin (CEO), and posterolateral ligament (PLL), representing the principal pillars of stability.

Results: Complete tears of the lateral collateral ligament complex (LCLC) and anterior bundle of the medial collateral ligament (aMCL) were highly prevalent in both stable and unstable groups, offering low specificity. In contrast, the concurrent disruption of the FPM and PLL, termed the "Double Hit" pattern, was the most powerful predictor, yielding a specificity of 98.8% and positive predictive value (PPV) of 91.7%. The Core-4 model showed excellent diagnostic accuracy (Area Under the Curve [AUC]: 0.979). While Score 2 elbows showed low instability (4.8%), Score 3 elbows exhibited a divergence: those with the Double Hit pattern had a 75% instability rate, while those without it remained stable (0%). All Score 4 elbows were unstable.

Conclusion: Mechanical instability following posterolateral elbow dislocation is a threshold-driven phenomenon resulting from the cumulative failure of critical stabilizers. The Double Hit pattern (concurrent failure of the FPM and PLL) represents the critical functional threshold for mechanical failure. By identifying high-risk subsets (Score 4 and Double Hit Score 3) with high specificity, the Core-4 model provides a definitive objective criterion for early surgical intervention while supporting functional rehabilitation for most stable dislocations.

Background: Cutibacterium acnes (C. acnes) is the most common pathogen in shoulder periprosthetic joint infection (PJI) but remains difficult to distinguish from contamination due to its low virulence and presence as a skin commensal. Diagnostic ambiguity and variable antibiotic resistance further complicate management.

Methods: We analyzed 87 C. acnes isolates from patients undergoing evaluation for shoulder PJI across two institutions. Isolates were obtained from intraoperative cultures and stored for subsequent analysis. Hemolysis, aerotolerance, and growth rate were assessed in vitro. Antimicrobial susceptibility to five antibiotics was determined using minimum inhibitory concentration (MIC) testing, with interpretive breakpoints defined by both the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Infection status was classified per the 2018 International Consensus Meeting (ICM) criteria into definite, probable, possible, or unlikely categories. Associations between phenotypic traits and infection classification were assessed using univariate and multivariable statistical models.

Results: Only 12.6% (n = 11) of cases met criteria for definite infection, while the majority (48.3%) were classified as probable. Hemolysis and aerotolerance were observed in 51.7% and 54.0% of isolates, respectively, and were strongly associated with one another (P < .001); however, neither phenotype was associated with infection classification in univariate or multivariable analysis. Clindamycin resistance was observed in a minority of isolates but varied by standard, with 12.6% classified as resistant by EUCAST and 6.9% as non-susceptible by CLSI. No isolates were resistant to vancomycin; doxycycline and rifampin MICs were uniformly low.

Conclusion: Neither hemolysis nor aerotolerance reliably distinguished definite PJI from non-definite cases, limiting their diagnostic utility in this cohort. Clindamycin resistance was uncommon, yet classification differed based on the interpretive criteria used (CLSI vs. EUCAST), highlighting potential inconsistencies in clinical reporting. Moreover, the predominance of "probable" infections illustrates a critical limitation of current consensus criteria, which may both underestimate true infection burden in indolent presentations and overestimate infection due to reliance on positive cultures in the absence of clear clinical findings. More precise diagnostic frameworks may help address current classification challenges and better support clinical decision-making in shoulder arthroplasty.

Background: Posterior glenoid dysplasia (PGD) has been described as an adaptive osseous change in young throwing athletes exposed to repetitive mechanical stress. However, prior studies have lacked consistent definitions, reliable classifications, or sport-specific analysis. This study aimed to analyze and classify PGD in young athletes across various sports and compare its proportion and severity between symptomatic baseball players and athletes from other sports.

Methods: We retrospectively reviewed 10 years of shoulder CT imaging data from 568 young athletes presenting with shoulder pain: 418 baseball players, 50 overhead athletes, and 100 athletes from other sports. Dysplasia of posterior to posteroinferior glenoid, bone defect size, and additional bone formation were assessed.

Results: We established a five-type classification system: Type 0 (normal sharp rim), Type 1 (smooth rounded rim), Type 2 (triangular defect), Type 3 (retreated joint surface with posterior bulging), and Type 4 (new bone formation). PGD was identified in 85.4% of baseball players, 32.0% of overhead athletes, and 9.0% of non-overhead athletes (p<0.001). Type 2 was most common in baseball players (42.6%), and advanced morphological PGD (Types 3-4) was present in 13.4% of baseball players but was absent in other groups.

Conclusion: PGD was more commonly observed among overhead athletes, particularly baseball players, within this symptomatic imaging cohort. Advanced morphologic types were identified predominantly in baseball players. These findings provide a structured framework for describing posterior glenoid morphology in throwing athletes and may facilitate future prospective studies investigating clinical relevance and natural history.