Transcriptome sequencing reveals inflammation and macrophage heterogeneity in subacromial bursa from degenerative shoulder disorders.

PURPOSE: We aimed to investigate the transcriptomic alterations that occur in the subacromial bursa (SAB) following degenerative or traumatic shoulder diseases. MATERIALS AND METHODS: RNA sequencing was employed to evaluate the transcriptomic alterations of the SAB in individuals afflicted with degenerative rotator cuff tear (RCT), traumatic RCT and proximal humerus fracture (PHF). To gain insights into the biological significance of differentially expressed genes (DEGs), we conducted an enrichment analysis utilizing Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We further utilized single-cell RNA sequencing datasets of SAB from a recently published study to explore the associated cellular dynamics and alterations. RESULTS: We detected 1,790 up-regulated and 1,964 down-regulated DEGs between degenerative RCT and PHF, 2,085 up-regulated and 1,919 down-regulated DEGs between degenerative RCT and traumatic RCT, and 20 up-regulated and 12 down-regulated DEGs between traumatic RCT and PHF. Given the similar expression pattern between traumatic RCT and PHF, they were integrated as the traumatic group. In comparison with the traumatic group, 1,983 up-regulated and 2,205 down-regulated DEGs were detected in degenerative SAB. Enrichment analysis of up-regulated DEGs uncovered an elevated inflammatory and immunologic responses in degenerative SAB. Single-cell transcriptomic analysis revealed macrophage represented the immune cell with the most DEGs between the degenerative and traumatic RCT. CONCLUSION: Our results revealed that the SAB in degenerative RCT exhibited a different transcriptional signature compared to that in traumatic RCT, and enrichment analysis showed immunologic and inflammatory activations. Macrophages may play a fundamental role in this process.

Cemented Versus Uncemented Reverse Shoulder Arthroplasty Treatment of Proximal Humerus Fractures: National Shoulder Arthroplasty Data from Türkiye.

Background: This study evaluated national trends in cemented and uncemented reverse shoulder arthroplasty (RSA) for proximal humerus fractures using a comprehensive national surgical database. This study aimed to compare RSA used in the treatment of proximal humerus fractures with the literature and to determine the country's trend. Methods: A cross-sectional study was conducted using the health records of individuals aged ≥ 18 years who underwent RSA for proximal humerus fractures between 2016 and 2022. Patients were divided into cemented and uncemented groups, and demographic data (age, sex), duration of hospital stay, transfusions, revisions, mortality, and Charlson Comorbidity Index (CCI) scores were analyzed. Results: A total of 618 cemented RSA and 1,364 uncemented RSA procedures were reviewed. Patients who underwent cemented RSA were significantly older than those who had uncemented RSA (p = 0.002). Transfusion rates were higher in the cemented RSA group (p = 0.006). The frequency of revision surgery was 6.1%. Younger age and male sex were associated with revision (p < 0.001). CCI scores were higher among transfused patients than non-transfused patients (p < 0.001). The incidence of cemented RSA was 11.7% and 49% in 2016 and 2022, respectively. Differences were found among hospital types and geographical regions. Conclusions: While cemented RSA has been gaining attention and increased application in recent years for proximal humerus fractures, uncemented RSA still predominates. The choice between these 2 methods is largely influenced by regional and hospital-level factors. The type of RSA and high CCI scores were found to have no significant impact on the risk of surgical revision.

Therapeutic Intervention for Osteoporosis of Surgical Cases With Non-Vertebral Fractures for Three Years in a Newly Established Rural Hospital in Japan.

Objectives Our hospital was newly opened in the spring of 2020 in a rural area of Japan, with a remarkably developing aging society and population decline. This study aimed to clarify and evaluate the practice of osteoporosis care in our hospital for three years since its establishment. We report a retrospective review of therapeutic interventions for osteoporosis for patients who underwent surgical treatment for non-vertebral fragility fractures in our hospital. Methods We evaluated the practice of osteoporosis intervention in patients who underwent surgery for proximal humerus fractures (PHFs), distal radius fractures (DRFs), or proximal femoral fractures (PFFs) from April 2020 to the end of March 2023. Results There were 115 surgical cases with non-vertebral fractures (10 patients with PHF, 41 patients with DRF, and 64 with PFF). Among the patients who had received osteoporosis treatment at other hospitals before the injury, only 15 (13.0%) patients had been administered therapeutic intervention for osteoporosis by other clinics or hospitals. Also, 82 (71.3%) patients were newly diagnosed with osteoporosis in our hospital after surgery according to the Japanese osteoporosis guideline. New postoperative osteoporosis interventions were administered to 39 (47.0%) patients, of which the rate was higher than the previous reports in Japan. While there was no significant difference between upper limb fracture and PFF in the percentage per young adult mean of spine areal bone marrow density (aBMD), the femoral neck aBMDs in the upper limb fracture group were significantly higher than in the PFF group. The serum total P1NP levels were significantly lower and the 25(OH)D levels were also greater in the upper limb fracture group than in the PFF group, whereas the serum TRACP-5b levels were not significantly different between the two groups. Two (1.7%) patients were affected with secondary fractures during the study period. Conclusions The rates of therapeutic intervention for osteoporosis of patients with non-vertebral fractures, especially in those with upper limb fractures, in our hospital were considered to be greater than those in the previous reports. However, the intervention rate for patients with PFFs was not much, and there was still room for improvement in our hospital concerning osteoporosis diagnosis and treatment.

Proximal humerus fracture and acromioclavicular joint dislocation.

Proximal humerus fractures and injuries to the acromioclavicular joint are among the most common traumatic diseases of the upper extremity. Fractures of the proximal humerus occur most frequently in older people and are an indicator fracture of osteoporosis. While a large proportion of only slightly displaced fractures can be treated non-operatively, more complex fractures require surgical treatment. The choice of optimal treatment and the decision between joint-preserving surgery by means of osteosynthesis or endoprosthetic treatment is often a difficult decision in which both fracture morphology factors and individual factors should be taken into account. If endoprosthetic treatment is indicated, satisfactory long-term functional and clinical results have been achieved with a reverse shoulder arthroplasty. Injuries to the acromioclavicular joint occur primarily in young, athletic individuals. The common classification according to Rockwood divides the injury into 6 degrees of severity depending on the dislocation. This classification forms the basis for the decision on non-operative or surgical treatment. The indication for surgical treatment for higher-grade injuries is the subject of controversial debate in the latest literature. In chronic injuries, an autologous tendon transplant is also performed. Whereas in the past, treatment was often carried out using a hook plate, which was associated with complications, the gold standard today is minimally invasive treatment using Endobutton systems. This review provides an overview of the two injury patterns and discusses the various treatment options.

Evaluating the association of radiographic parameters of proximal humerus fractures managed conservatively with functional outcomes.

INTRODUCTION: Treatment of proximal humerus fractures remains controversial. Understanding the factors that can affect the long-term functional outcomes can aid with management choices. This primary aim of this paper is to evaluate the association of radiographic parameters with functional outcomes. METHODS: Radiographic parameters [Caput-collum-diaphyseal (CCD) angles, Y-scapular angles, and humeral head height (HHH)] were studied. The patients were split into varus and valgus groups based on the CCD angles and retroverted and anteverted groups based on Y-scapular angles. Functional outcome was measured by Oxford Shoulder Score (OSS), Constant Shoulder Score (CSS), and quick Disabilities of Arm, Shoulder and Hand score at 1 year follow-up. Intra- and interrater reliability were measured with the intraclass correlation coefficients (ICCs). Receiver operator curve (ROC) analysis and logistic regression analysis defined the optimal value for abnormalities on radiographic evaluation as an outcome predictor. RESULTS: 111 patients were recruited (mean age 69, 78% female). Median final radiographic assessment was at 7 months. Mean initial/final CCD was 119o /111o (varus, n = 36) and 153o/140o (valgus, n = 75). Mean initial/final Y-scapula angle was 27o/27o (retroversion, n = 101) and 70o/40o (anteversion, n = 9). There was a significant relationship between OSS and final Y-scapular angle in the retroverted group (adj coeff 0.034, p = 0.009) with optimum predictive retroversion angulation of 25o predicting poor functional outcome (OSS < 40), area under the ROC curve of 0.614. Higher initial valgus and retroversion significantly predicted more change in the final angle (adj coeff - 0.349, p = 0.002, adj coeff - 0.527, p < 0.001 respectively). Both intra-rater and inter-rater reliability for the radiographic parameters were excellent (ICC > 0.9). CONCLUSION: Radiographic parameters whilst having excellent reliability, have a limited ability to predict short-term functional recovery. The extent of retroversion is the most important predictor for functional recovery with 25o a cut-off guide. Fractures with a higher initial valgus and retroversion tend to displace more.

Adoption of Reverse Total Shoulder Arthroplasty for Surgical Treatment of Proximal Humerus Fractures Differs by Patient Race.

BACKGROUND: Reverse total shoulder arthroplasty (rTSA) has gained popularity for the operative treatment of proximal humerus fractures (PHF). The purpose of this study was to compare racial differences in surgical management of PHF between open reduction and internal fixation (ORIF), hemiarthroplasty, and rTSA. Our hypothesis was that there would be no difference in fixation by race. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for ORIF, rTSA, and hemiarthroplasty between 2006 and 2020 for patients with a PHF. Race, ethnicity, age, sex, body mass index (BMI), and American Society of Anesthesiologists (ASA) class were recorded. Chi squared tests were performed to assess relationships between patient factors and operative intervention. Factors significant at the 0.10 level in univariable analyses were included in a multivariable multinomial model to predict operative intervention. RESULTS: 7,499 patients underwent surgical treatment for a PHF, including 526 (7%) undergoing hemiarthroplasty, 5,011 (67%) undergoing ORIF, and 1,962 (26%) undergoing rTSA. 27% of white patients with PHF underwent rTSA compared to 21% of Black patients, 16% of Asian patients, and 14% of Native American and Alaskan Native patients (p<0.001). In the multivariable analysis, utilization of rTSA increased over time (OR 1.2 per year since 2006, p < 0.001) and hemiarthroplasty decreased over time (OR 0.86 per year since 2006, p < 0.001). Non-white patients had significantly lower odds of undergoing rTSA versus ORIF (OR 0.75, 95% CI 0.58-0.97), as did male patients (OR 0.77, 95% CI 0.66-0.88). Patients over 65 (OR 3.86, 95% CI 3.39-4.38), patients with higher ASA classifications (ASA2: OR 3.24, 95% CI 1.86-5.66, ASA3: OR 4.77, 95% CI 2.74-8.32, ASA4: OR 5.25, 95% CI 2.89-9.54), and patients who were overweight (OR 1.33, 95% CI 1.14-1.55) or obese (OR 1.52, 95% CI 1.32-1.75) had higher odds of undergoing rTSA versus ORIF. DISCUSSION: As utilization of rTSA increases, understanding disparities in surgical treatment of PHF is crucial to improving outcomes and equitable access to emerging orthopedic technologies. While patient factors such as age, BMI, and comorbidities are known to directly impact outcomes and thus may be predictive of the type of surgical intervention, patient race should not dictate treatment.

Fixation of Paediatric Proximal Humerus Fractures Using Percutaneous Pinning: A Case Report.

A 12-year-old male came to our Emergency Department with chief complaints of pain and inability to move the right shoulder for one day following a fall while playing. The range of motion of the right shoulder was restricted and painful in all directions. Initial radiographs revealed a transverse, displaced proximal humerus fracture at the head-shaft junction. The patient was managed by closed reduction internal fixation with percutaneous K-wiring (Kirschner wires). The K-wires were removed after four weeks, and the shoulder was mobilized. The patient had a near-normal and pain-free range of motion at three months of follow-up. Percutaneous K-wiring remains a viable option for the treatment of paediatric proximal humerus fractures, and good post-operative rehabilitation can help restore near-normal function, as demonstrated in this report.

Locked Stem Reverse Total Shoulder Arthroplasty for Complex Proximal Humerus Fracture in the Elderly: Clinical and Radiological Short-Term Results.

Purpose: To evaluate both the short-term clinical and radiological results of reverse shoulder arthroplasty (RSA) with uncemented locked stem in the management of a proximal humerus fracture (PHFs) in the elderly. Methods: Retrospective study including 40 consecutive 3-4 part proximal humerus fractures treated with reverse shoulder arthroplasty with a minimum of 24 months follow-up. In all the cases, the greater tuberosity (GT) was reattached with a standardized suture technique and a local horseshoe bone graft. All the patients were assessed at the 24-month follow-up with Constant-Murley Score (CMS) and Visual Analog Score (VAS). Radiographic healing of the greater tuberosity was noted in addition to stem locking screws radiographic changes. Complications and revision rates were reported. Results: Mean final CMS for this cohort was 80 points. The greater tuberosity healed in the anatomic position in 90% of the cases (N = 36), obtaining an average CMS of 80 in these patients. Healing of the greater tuberosity did not occur in 10% of the cases (N = 4), obtaining an average CMS of 60. All patients scored above 100° in forward elevation with a mean of 140°. Mean active external rotation was 30°. Low-grade scapular notching was reported in <1% of the cases. Major complications were reported in one patient with an acromial fracture. No complications or loosening of stem locking screws were noted. There were no reoperations. Conclusion: In the elderly population, reverse shoulder arthroplasty utilizing a fracture-specific locking stem, low-profile metaphysis, suture-friendly groove, meticulous suture technique, and local bone grafting allows adequate fixation, variable prosthesis height adjustment, and enhances greater tuberosity healing. This approach yields positive short-term clinical outcomes without complications related to the stem's locking screws. Level of Evidence: Level IV Retrospective Case Series.

Open reduction and internal fixation of the proximal humerus with femoral head allograft augmentation "the French fry technique".

Fractures of the proximal humerus account for 4%-8% of injuries to the appendicular skeleton. Most are stable, minimally displaced osteoporotic fractures in the elderly, and are the result of low-energy falls. A large majority of these patients regain adequate shoulder function without operative intervention. Surgery is considered in approximately 20% of patients because they require improved shoulder function for their activities of daily living or because of the significant deformity of their fracture and the need to restore functional alignment, length, and rotation in active, higher demand individuals. However, fixation of these fractures can pose a challenge due to poor bone quality and displacing forces of the rotator cuff. This is especially true in 3-part and 4-part fractures. These factors lead to the high failure rates seen with early attempts at osteosynthesis. In the last 2 decades, locking plate technology has been an innovation in treating these complex fractures. Despite the improvements in torsional strength and rigidity, outcome studies on locking plate technology demonstrate equivocal results with complication rates as high as 20%-30% and a revision rate of 10%. Specifically, these complications include avascular necrosis, varus collapse, intra-articular screw penetration, and postoperative stiffness. Varus collapse occurs when the weak osteoporotic bone fails around the implant. In turn, fibular strut endosteal augmentation was introduced to provide additional support and decrease implant failure rates in displaced fractures with varus coronal malalignment and significant metaphyseal bone loss. Although clinically successful and biomechanically superior to plate-only constructs, a few concerns remain. In turn, we introduce a novel technique of creating individual cancellous femoral head allograft struts or "French fries" that provides structural support for the humeral head but does not have the potential problems of a cortical fibular strut.

Management of greater tuberosity fracture dislocations of the shoulder.

Background: Despite extensive literature dedicated to determining the optimal treatment of isolated greater tuberosity (GT) fractures, there have been few studies to guide the management of GT fracture dislocations. The purpose of this review was to highlight the relevant literature pertaining to all aspects of GT fracture dislocation evaluation and treatment. Methods: A narrative review of the literature was performed. Results: During glenohumeral reduction, an iatrogenic humeral neck fracture may occur due to the presence of an occult neck fracture or forceful reduction attempts with inadequate muscle relaxation. Minimally displaced GT fragments after shoulder reduction can be successfully treated nonoperatively, but close follow-up is needed to monitor for secondary displacement of the fracture. Surgery is indicated for fractures with >5 mm displacement to minimize the risk of subacromial impingement and altered rotator cuff biomechanics. Multiple surgical techniques have been described and include both open and arthroscopic approaches. Strategies for repair include the use of transosseous sutures, suture anchors, tension bands, screws, and plates. Good-to-excellent radiographic and clinical outcomes can be achieved with appropriate treatment. Conclusions: GT fracture dislocations of the proximal humerus represent a separate entity from their isolated fracture counterparts in their evaluation and treatment. The decision to employ a certain strategy should depend on fracture morphology and comminution, bone quality, and displacement.

Assessment of Functional Outcome and Postoperative Complications in Proximal Humerus Fracture Patients Managed With Proximal Humerus Internal Locking System (PHILOS) Plating.

BACKGROUND: Proximal humerus fractures are primarily common in the old age group. The appropriate approach to managing such displaced and comminuted fracture patterns is often questionable. Hence, this study was conducted to assess the functional outcome of proximal humerus fractures following treatment with a proximal humerus locking plate and to assess the frequency of complications in such patients. METHODOLOGY: In this robust study, 33 cases of proximal humerus fractures underwent surgical management at a prestigious teaching hospital from February 2021 to August 2022 utilizing a proximal humerus internal locking system (PHILOS) plate. The NEER classification was employed to categorize the fractures, and the NEER score was used for functional assessment. It's crucial to note that individuals with pathological fractures, associated injuries in the ipsilateral limb, nerve injuries, and cases of open fracture were rigorously excluded from the study. RESULTS: The mean age was 47 ± 5.2 years. Based on NEER's classification, the distribution of fractures was as follows: two-part fractures accounted for 18.18% (n = 6) of cases, three-part fractures for 54.54% (n = 18) of cases, and four-part fractures for 27.27% (n = 9) of cases. A history of road traffic accidents and falls was reported in 54.54% (n = 18) and 45.45% (n = 15) of cases, respectively. Functional outcome assessment utilizing NEER's score revealed a minimum score of 48 and a maximum of 96, with an average score of 82.96 ± 12.73. Notably, 39% of patients demonstrated excellent results, 27% exhibited satisfactorily, 21% manifested unsatisfactorily, and 12.12% presented failure outcomes. Of the 33 operated cases, 81.8% (n = 27) exhibited no complications during follow-up. The predominant complication observed was shoulder stiffness (9.09%, n = 3), followed by Varus mal-union (6.06%, n = 2), and superficial surgical site infection (3.03%, n = 1), managed with debridement and antibiotics leading to subsequent resolution. CONCLUSIONS: Managing proximal humerus fractures has consistently posed a formidable challenge. Our study indicates that using the PHILOS plate represents a reliable option for addressing such fractures. This plate provides sturdy fixation, facilitates early mobilization, and culminates in exceptional functional outcomes. The insights gained from this study can inform clinical decision-making and guide orthopedic surgeons in selecting the appropriate treatment strategy for proximal humerus fracture patients.

Finite element analysis and biomechanical study of "sandwich" fixation in the treatment of elderly proximal humerus fractures.

Proximal humerus fractures (PHFs) are common in the elderly and usually involve defects in the medial column.The current standard for medial column reconstruction is a lateral locking plate (LLP) in combination with either an intramedullary fibula support or an autogenous fibula graft. However, autogenous fibula graft can lead to additional trauma for patients and allogeneic fibular graft can increase patients' economic burden and pose risks of infection and disease transmission. The primary objective of this study was to introduce and assess a novel "Sandwich" fixation technique and compare its biomechanical properties to the traditional fixation methods for PHFs. In this study, we established finite element models of two different internal fixation methods: LLP-intramedullary reconstruction plate with bone cement (LLP-IRPBC) and LLP-intramedullary fibula segment (LLP-IFS). The biomechanical properties of the two fixation methods were evaluated by applying axial, adduction, abduction, torsional loads and screw extraction tests to the models. These FEA results were subsequently validated through a series of biomechanical experiments. Under various loading conditions such as axial, adduction, abduction, and rotation, the LLP-IRPBC group consistently demonstrated higher structural stiffness and less displacement compared to the LLP-IFS group, regardless of whether the bone was in a normal (Nor) or osteoporotic (Ost) state. Under axial, abduction and torsional loads, the maximum stress on LLPs of LLP-IRPBC group was lower than that of LLP-IFS group, while under adduction load, the maximum stress on LLPs of LLP-IRPBC group was higher than that of LLP-IFS group under Ost condition, and almost the same under Nor condition. The screw-pulling force in the LLP-IRPBC group was 1.85 times greater than that of the LLP-IFS group in Nor conditions and 1.36 times greater in Ost conditions. Importantly, the results of the biomechanical experiments closely mirrored those obtained through FEA, confirming the accuracy and reliability of FEA. The novel "Sandwich" fixation technique appears to offer stable medial support and rotational stability while significantly enhancing the strength of the fixation screws. This innovative approach represents a promising strategy for clinical treatment of PHFs.

Preoperative chronic steroid use as a risk factor for complications following open reduction internal fixation for proximal humerus fracture.

PURPOSE: The primary objective of this study was to investigate the association between preoperative chronic steroid use and postoperative complications following open reduction internal fixation (ORIF) for proximal humerus fractures (PHF). METHODS: The American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP) database was queried for all patients who underwent PHF ORIF between 2015 and 2021. A total of 6,273 patients were included in this study, of which 3.4% (n = 212) were in the chronic steroid use cohort. Patient characteristics including demographics, comorbidities, and 30-day postoperative complications after PHF ORIF were collected. Bivariate logistic regression and multivariate logistic regression analysis, adjusted for all significantly associated variables, was conducted to investigate the relationship between preoperative chronic steroid use and postoperative complications. RESULTS: Chronic steroid use was significantly associated with age ≥ 75 (p < 0.001), male gender (p =0.006), dependent functional status (p = 0.008), American Society of Anesthesiologist (ASA) ≥ 3 (p < 0.001), CHF (p = 0.007), hypertension (p < 0.001), COPD (p < 0.001), bleeding disorder (p = 0.007), ascites (p = 0.040), disseminated cancer (p< 0.001), and systemic sepsis (p < 0.001). After adjusting for all significantly associated variables, chronic steroid use was independently associated with major complication (OR 1.60, 95% CI 1.06-2.43; p = 0.026), and non-home discharge (OR 1.05, 95% CI 1.01-1.08; p = 0.014). CONCLUSION: Preoperative chronic steroid use is associated with increasing rate of postoperative complications following PHF ORIF. Better understanding and characterizing chronic steroid use as a preoperative risk factor can aid physicians in risk stratification to reduce rates of postoperative complications following PHF ORIF. LEVEL OF EVIDENCE: III. Retrospective Cohort Comparison; Prognosis Study.

Comparison of clinical outcomes and complications in 2-part vs. 3- or 4-part proximal humerus fractures treated using an intramedullary nail designed to capture the tuberosities.

Background: Intramedullary nail fixation for proximal humerus fractures has been shown to provide satisfactory results. The quality of reduction correlates with clinical outcomes, the rate of complications, avascular necrosis, and postoperative loss of fixation. The purpose of this study was to evaluate the clinical outcomes and complications of 2-part proximal humerus fractures compared to 3- or 4-part proximal humerus fractures. Methods: A single-center retrospective review was carried out of patients who underwent an intramedullary nail for a proximal humerus fracture by one of three surgeons between the years of 2009 and 2022, and who had a minimum of 12-months follow-up. Fracture pattern, American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score, satisfaction, pain score, range of motion, and complications were recorded. The mechanism of injury (high energy vs. low energy), method of reduction (open vs. percutaneous), and evidence of radiographic healing were assessed. A P value of <.05 was considered to be statistically significant. Results: The study included 78 patients (62 female, 16 male). The number of patients in each group (2-part, N = 32 vs. 3- or 4-part, N = 46), mean age (2-part, 64 vs. 3- or 4-part,61), follow-up (2-part, 42.5 months vs. 3- or 4-part, 34.5 months), injury type (2-part, 88% low energy vs. 3- or 4-part, 78% low energy), and method of reduction (2-part, 81% percutaneous vs. 3- or 4-part 72% percutaneous) were similar among the two groups. There was fracture union in all patients. All patients demonstrated satisfactory patient-reported outcome measures. However, 2-part fractures did have a significantly lower pain score, higher Single Assessment Numeric Evaluation score, and higher percentage of patients being satisfied or very satisfied when compared to 3- or 4-part fractures. The rate of subsequent procedures was 13% (n = 4) in 2-part fractures compared to 19% (n = 9) in 3- or 4-part fractures but was not statistically significant (P = .414). The overall rate of conversion to arthroplasty was 3.2% in 2-part fractures and 10.4% in 3- or 4-part fractures. Conclusion: Multipart proximal humerus fractures remain difficult to treat. However, this study demonstrates an overall acceptable outcome with improvement in range of motion, patient-reported outcomes, and similar complication rates between 2-part and 3- or 4-part proximal humerus fractures treated with an intramedullary nail. However, the improvement in certain parameters is not as marked in 3- or 4-part fractures as 2-part fractures.

Preoperative factors predict prolonged length of stay, serious adverse complications, and readmission following operative intervention of proximal humerus fractures: a machine learning analysis of a national database.

Background: Proximal humerus fractures are a common injury, predominantly affecting older adults. This study aimed to develop risk-prediction models for prolonged length of hospital stay (LOS), serious adverse complications, and readmission within 30 days of surgically treated proximal humerus fractures using machine learning (ML) techniques. Methods: Adult patients (age >18) who underwent open reduction internal fixation (ORIF), hemiarthroplasty, or total shoulder arthroplasty for proximal humerus fracture between 2016 and 2021 were included. Preoperative demographic and clinical variables were collected for all patients and used to establish ML-based algorithms. The model with optimal performance was selected according to area under the curve (AUC) on the receiver operating curve (ROC) curve and overall accuracy, and the specific predictive features most important to model derivation were identified. Results: A total of 7473 patients were included (72.1% male, mean age 66.2 ± 13.7 years). Models produced via gradient boosting performed best for predicting prolonged LOS and complications. The model predicting prolonged LOS demonstrated good discrimination and performance, as indicated by (Mean: 0.700, SE: 0.017), recall (Mean: 0.551, SE: 0.017), accuracy (Mean: 0.717, SE: 0.010), F1-score (Mean: 0.616, SE: 0.014), AUC (Mean: 0.779, SE: 0.010), and Brier score (Mean: 0.283, SE: 0.010) Preoperative hematocrit, preoperative platelet count, and patient age were considered the strongest predictive features. The model predicting serious adverse complications exhibited comparable discrimination [precision (Mean: 0.226, SE: 0.024), recall (Mean: 0.697, SE: 0.048), accuracy (Mean: 0.811, SE: 0.010), F1-score (Mean: 0.341, SE: 0.031)] and superior performance relative to the LOS model [AUC (Mean: 0.806, SE: 0.024), Brier score (Mean: 0.189, SE: 0.010), noting preoperative hematocrit, operative time, and patient age to be most influential. However, the 30-day readmission model achieved the weakest relative performance, displaying low measures of precision (Mean: 0.070, SE: 0.012) and recall (Mean: 0.389, SE: 0.053), despite good accuracy (Mean: 0.791, SE: 0.009). Conclusion: Predictive models constructed using ML techniques demonstrated favorable discrimination and satisfactory-to-excellent performance in forecasting prolonged LOS and serious adverse complications occurring within 30 days of surgical intervention for proximal humerus fracture. Modifiable preoperative factors such as hematocrit and platelet count were identified as significant predictive features, suggesting that clinicians could address these factors during preoperative patient optimization to enhance outcomes. Overall, these findings highlight the potential for ML techniques to enhance preoperative management, facilitate shared decision-making, and enable more effective and personalized orthopedic care by exploring alternative approaches to risk stratification.

Comparison of classical and minimally invasive superolateral approach for reconstruction of proximal humerus fractures with locking plates.

CONTEXT: Minimally invasive (MI) approaches are purported to present advantages for osteosynthesis when compared with conventional approaches. This study aimed to compare the medium-term clinical and radiological outcomes of patients with proximal humerus fractures treated by plate osteosynthesis with conventional and MI superolateral approaches. METHOD: The study carried out was a retrospective monocentric comparative analysis. Forty-three cases were followed up - 18 were treated with an MI approach and 25 with a conventional approach. Constant-Murley, DASH and SSV scores were established and standard complications were investigated. RESULTS: No significant differences in functional scores or complications were found between the 2 groups. The only significant difference was for pain which was significantly lower for the MI group. The overall revision rate was 18.3 %. The mean adjusted Constant-Murley for the entire population was 80.1 ± 20.2; the mean DASH score was 17.8 ± 15.9 and the mean SSV was 73.2 ± 19.5. CONCLUSION: This study did not demonstrate any significant differences between the 2 approaches. Given the low patient population in our series, the superiority of the MI approach - as indicated in the literature - was not proven.