Progressive Improvement in 5-Year Survival Rates for Extremity Soft Tissue Sarcomas from 1999 to 2019.

Background: Extremity soft-tissue sarcoma (ESTS) is a group of rare, heterogeneous malignancies. Previous studies have demonstrated a progressive improvement in 5-year survival rate over time, but recent trends are unknown. Therefore, this study aimed to provide an update on the clinical characteristics and 5-year survival rate of ESTS from 1999 to 2019. Methods: This retrospective cohort study used the Surveillance, Epidemiology, and End Results (SEER) database. Overall, 5,654 patients over the age of 15 years with primary ESTS diagnosed between 1999 and 2019 were included. Data on patient demographics, clinical characteristics, and survival were extracted. Patients were grouped by year of diagnosis: 1999-2005, 2006-2012, and 2013-2019. Kaplan-Meier and Cox proportional hazards regression analyses were performed. Results: ESTS occurred primarily in the lower extremity (76.1%) and was frequently grade III (58.3%), >5 cm in size (69.9%), and without metastasis (77.9%) at diagnosis. Furthermore, there was a significant increase in the proportion of patients over age 60 (p < 0.001) and without metastasis (p < 0.001) over the study period. The 5-year survival rate successively improved, from 47% in 1999-2005, to 61% in 2006-2012, to 78% in 2013-2019. Similarly, in multivariate analysis, the mortality rate progressively declined from a hazard ratio (HR) of 3.4 in 1999-2005 to an HR of 2.1 in 2006-2012, with the 2013-2019 group having the best overall survival (p < 0.001). Age, tumor size, grade, and metastasis were negative prognostic factors for survival; radiation and surgery were positive prognostic factors. Conclusions: The 5-year overall survival rate for ESTS progressively improved over the 20-year study period, perhaps due to an increasing proportion of older patients diagnosed with local disease. These findings may also be related to earlier detection or more effective treatment over the study period.

The use of weakly supervised machine learning for necrosis assessment in patients with osteosarcoma: A pilot study.

Percent necrosis (PN) following chemotherapy is a prognostic factor for survival in osteosarcoma. Pathologists estimate PN by calculating tumor viability over an average of whole-slide images (WSIs). This non-standardized, labor-intensive process requires specialized training and has high interobserver variability. Therefore, we aimed to develop a machine-learning model capable of calculating PN in osteosarcoma with similar accuracy to that of a musculoskeletal pathologist. In this proof-of-concept study, we retrospectively obtained six WSIs from two patients with conventional osteosarcomas. A weakly supervised learning model was trained by using coarse and incomplete annotations of viable tumor, necrotic tumor, and nontumor tissue in WSIs. Weakly supervised learning refers to processes capable of creating predictive models on the basis of partially and imprecisely annotated data. Once "trained," the model segmented areas of tissue and determined PN of the same six WSIs. To assess model fidelity, the pathologist also estimated PN of each WSI, and we compared the estimates using Pearson's correlation and mean absolute error (MAE). MAE was 15% over the six samples, and 6.4% when an outlier was removed, for which the model inaccurately labeled cartilaginous tissue. The model and pathologist estimates were strongly, positively correlated (r = 0.85). Thus, we created and trained a weakly supervised machine learning model to segment viable tumor, necrotic tumor, and nontumor and to calculate PN with accuracy similar to that of a musculoskeletal pathologist. We expect improvement can be achieved by annotating cartilaginous and other mesenchymal tissue for better representation of the histological heterogeneity in osteosarcoma.

The efficacy and safety of direct oral anticoagulants compared with low-molecular-weight heparin for venous thromboembolism prophylaxis after surgical resection of primary lower extremity bone or soft-tissue sarcoma.

INTRODUCTION: The incidence of postoperative venous thromboembolism (VTE) and wound complications is greater after sarcoma resection. We sought to identify differences in postoperative VTE and bleeding complications with direct oral anticoagulants (DOACs) versus low-molecular-weight heparin (LMWH) following resection of lower extremity primary bone or soft tissue sarcoma. METHODS: We retrospectively identified 2083 patients from the PearlDiver database who underwent resection of primary bone or soft tissue sarcoma of the lower extremity from January 2010 to October 2021 and prescribed LMWH or DOAC within 90-days postoperatively. The primary outcomes were comparison of postoperative incidence and odds of deep venous thrombosis (DVT), pulmonary embolism (PE), and bleeding complications within 90-days following resection. RESULTS: Patients prescribed DOACs had a greater odds of DVT (odds ratio [OR]: 1.60; 95% confidence interval [CI]: 1.06-2.41; p = 0.024) and PE (OR: 3.38; 95% CI: 1.96-5.86; p < 0.001) within 90-days following resection of bone sarcoma when compared with the LMWH cohort. Patients undergoing resection of soft tissue sarcomas also had greater odds DVT (OR: 1.65; 95% CI: 1.09-2.49; p = 0.016) and PE (OR: 2.62; 95% CI: 1.52-4.54; p < 0.001) in the DOAC cohort. There was no difference in the odds of bleeding complications. CONCLUSION: This study demonstrated an increased incidence and odds of VTE, but not bleeding complications, when using DOACs versus LMWH after primary bone or soft tissue sarcoma resection. LEVEL OF EVIDENCE: Level III.

The low and disproportionate utilization of antiresorptive therapy in patients with osseous metastasis.

Introduction: Antiresorptive therapies are commonly utilized to mitigate and prevent skeletal-related-events in patients with metastatic osseous disease. However, limited data exists on the incidence or factors associated with prescription of antiresorptives or their effects on the incidence of pathologic fractures in patients with osseous metastatic disease. The aims of this study were to determine 1) the proportion of patients with osseous metastasis who receive antiresorptive therapy and sustain a pathologic fracture within 2-years of a new diagnosis, 2) factors associated with sustaining a pathologic fracture, and 3) factors are associated with the likelihood of receiving antiresorptive therapy. Methods: Between January 2010 and October 2021, 1,492,301 patients with a new diagnosis of osseous metastasis were captured in the Mariner dataset of the PearlDiver database. Patients were identified using International Classification of Disease (ICD) 10 codes for osseous metastasis. We excluded patients with a prior diagnosis of osseous metastasis and if they had less than two-years of follow-up. There were 696,459 patients (46.7 %) included for analysis. Of these patients, 63 % (N = 437,716) were over the age of 65, 46 % were women, and 5.6 % had Medicaid insurance. We identified patients who were prescribed antiresorptive therapy within 2-years of a new diagnosis of osseous metastasis. Cox proportional hazard ratio models were created to predict factors associated with 1) pathologic fracture and 2) receiving antiresorptive therapy within 2-years of a new diagnosis of osseous metastasis, respectively. Results: The incidence of antiresorptive therapy prescription was 7.7 % in our cohort. The incidence of pathologic fracture within 2-years of a new diagnosis was 7.3 %. The risk of sustaining a pathologic fracture was higher for patients aged 35-44 (HR 1.27 [95 % CI 1.08-1.51]; p = 0.004), those with primary kidney cancer (HR 1.78 [95 % CI 1.71-1.85]; p < 0.001), p = 0.005), multiple myeloma (HR 2.49 [95 % CI 2.39-2.59]; p < 0.001), and Medicaid insurance (HR 1.17 [95 % CI 1.13-1.21]; p < 0.001). The risk of sustaining a pathologic fracture was lower for patients on antiresorptive therapy (HR 0.71 [95 % CI 0.66-0.83]; p < 0.001). Increasing age was an independent predictor for antiresorptive therapy prescription (HR 1.77-16.38, all p < 0.05). Male sex as well as diagnosis of primary prostate, lung, or kidney cancer and Medicaid insurance were negative predictors for antiresorptive prescription (HR 0.15-0.87, all p < 0.001). Conclusions: The utilization of antiresorptive therapy in patients with osseous metastases remains unacceptably low, with only 7.7% patients being prescribed these therapies, despite shown efficacy in reduction of pathologic fractures incidences. This study identified younger patients, males, and those diagnosed with primary prostate, kidney, and lung cancers to be at increased risk of not being prescribed antiresorptive therapy, suggesting possible bias in prescription patterns. Greater efforts are needed by providers who care for this vulnerable population to increase the utilization and reduce disparities of prescribing antiresorptive therapy.

Metastatic sarcomatoid carcinoma to bone.

BACKGROUND AND OBJECTIVES: Distinguishing sarcomatoid carcinoma from primary sarcoma is clinically important. We sought to characterize metastatic sarcomatoid bone disease and its management. METHODS: We analyzed the characteristics of all cases of sarcomatoid carcinoma to bone at a single institution from 2001 to 2021, excluding patients with nonosseous metastases. Survival was evaluated using the Kaplan-Meier method. RESULTS: We identified 15 cases of metastatic sarcomatoid carcinoma to bone. In seven cases the primary cancer was unknown at presentation. Renal cell carcinoma was suspected or confirmed in nine cases. Nine patients presented with pathologic fracture and two with concomitant visceral metastases. All patients underwent image-guided core needle or open biopsy. Ten required surgery for discrete osseous metastases; in four cases definitive surgery was delayed (median delay, 19 days) due to inability to rule out sarcoma with frozen section. No patients required reoperation or had construct failure. Thirteen died of disease; median survival was 17.5 months (interquartile range, 6.2-25.1). CONCLUSIONS: Metastatic sarcomatoid carcinoma is a clinically challenging entity. Multidisciplinary input and communication are key to identifying the primary carcinoma, locating osseous metastases, and defining an operative fixation that will survive the remainder of the patient's life.

Incidence of and Risk Factors for Thromboembolism After Endoprosthetic Reconstruction in Musculoskeletal Oncology Patients.

BACKGROUND: The aim of the present study was to assess the incidence of and risk factors for thromboembolic events-including assessment of the intraoperative use of tranexamic acid and postoperative use of chemical thromboprophylaxis-in patients undergoing operative treatment of primary bone or soft-tissue sarcoma or oligometastatic bone disease. METHODS: This study was performed as a secondary analysis of prospective data collected from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) randomized controlled trial, which included 604 patients ≥12 years old who underwent surgical resection and endoprosthetic reconstruction for either primary bone or soft-tissue sarcoma or oligometastatic disease of the femur or tibia. We determined the incidence of thromboembolic events in these patients and evaluated potential risk factors, including patient age, sex, antibiotic treatment group, type of tumor (i.e., primary bone or soft-tissue sarcoma or metastatic bone disease), intraoperative tranexamic acid, tourniquet use, operative time, pathologic characteristics (i.e., American Joint Committee on Cancer grade, vascular invasion, and percent necrosis), postoperative chemical thromboprophylaxis regimen, and surgical site infection. Continuous variables were assessed with use of the Student t test. Categorical variables were assessed with use of the Pearson chi-square test, except when the expected cell counts were <5, in which case the Fisher exact test was utilized. Significance was set at 0.05. RESULTS: Postoperative thromboembolic events occurred in 11 (1.8%) of 604 patients. Patients who experienced a thromboembolic event had a significantly higher mean (± standard deviation) age (59.6 ± 17.5 years) than those who did not experience a thromboembolic event (40.9 ± 21.8; p = 0.002). Patients randomized to the long-term antibiotic group had a significantly higher incidence of thromboembolic events (9 of 293; 3.1%) than those randomized to the short-term antibiotic group (2 of 311; 0.64%; p = 0.03). Neither intraoperative tranexamic acid nor postoperative chemical thromboprophylaxis were significantly associated with the occurrence of a thromboembolic event. CONCLUSIONS: Although relatively rare in the PARITY cohort, thromboembolic events were more likely to occur in older patients and those receiving long-term prophylactic antibiotics. Intraoperative tranexamic acid and postoperative chemical thromboprophylaxis were not associated with a greater incidence of thromboembolic events. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Does the Use of Negative Pressure Wound Therapy and Postoperative Drains Impact the Development of Surgical Site Infections?: A PARITY Trial Secondary Analysis.

BACKGROUND: Surgical site infections (SSIs) represent a major complication following oncologic reconstructions. Our objectives were (1) to assess whether the use of postoperative drains and/or negative pressure wound therapy (NPWT) were associated with SSIs following lower-extremity oncologic reconstruction and (2) to identify factors associated with the duration of postoperative drains and with the duration of NPWT. METHODS: This is a secondary analysis of the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial, a multi-institution randomized controlled trial of lower-extremity oncologic reconstructions. Data were recorded regarding the use of drains alone, NPWT alone, or both NPWT and drains, including the total duration of each postoperatively. We analyzed postoperative drain duration and associations with tourniquet use, intraoperative thromboprophylaxis or antifibrinolytic use, incision length, resection length, and total operative time, through use of a linear regression model. A Cox proportional hazards model was used to evaluate the independent predictors of SSI. RESULTS: Overall, 604 patients were included and the incidence of SSI was 15.9%. Postoperative drains alone were used in 409 patients (67.7%), NPWT alone was used in 15 patients (2.5%), and both postoperative drains and NPWT were used in 68 patients (11.3%). The median (and interquartile range [IQR]) duration of drains and of NPWT was 3 days (IQR, 2 to 5 days) and 6 days (IQR, 4 to 8 days), respectively. The use of postoperative drains alone, NPWT alone, or both drains and NPWT was not associated with SSI (p = 0.14). Increased postoperative drain duration was associated with longer operative times and no intraoperative tourniquet use, as shown on linear regression analysis (p < 0.001 and p = 0.03, respectively). A postoperative drain duration of ≥14 days (hazard ratio [HR], 3.6; 95% confidence interval [CI], 1.3 to 9.6; p = 0.01) and an operative time of ≥8 hours (HR, 4.5; 95% CI, 1.7 to 11.9; p = 0.002) were independent predictors of SSI following lower-extremity oncologic reconstruction. CONCLUSIONS: A postoperative drain duration of ≥14 days and an operative time of ≥8 hours were independent predictors of SSI following lower-extremity oncologic reconstruction. Neither the use of postoperative drains nor the use of NPWT was a predictor of SSI. Future research is required to delineate the association of the combined use of postoperative drains and NPWT with SSI. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Sarcoma Happens: A Reminder for Arthroscopic Surgeons.

Primary intra-articular sarcomas are rare and present with nonspecific symptoms such as pain or swelling. Due to nonspecific symptoms, patients may undergo routine diagnostic arthroscopy, which ultimately leads to sarcoma diagnosis. Here we present four patients with intra-articular sarcomas of the knee diagnosed after arthroscopy. The goal of this study is to highlight the importance of including malignant bone and soft-tissue sarcomas in the differential diagnosis of patients with nonspecific knee symptoms. A case series was developed from a retrospective review of prospectively collected data from our institution's orthopedic oncology database. Patients who underwent arthroscopic procedures on the knee and who were diagnosed with intra-articular sarcomas postoperatively from 2014 to 2019 were identified. All patients underwent diagnosis, staging, and multidisciplinary evaluation and treatment. Clinical characteristics, oncologic considerations, and surgical outcomes are described. Four patients with intra-articular sarcomas of the knee diagnosed after arthroscopy for non-oncologic concerns were identified: two synovial sarcomas, one Ewing sarcoma of bone, and one osteosarcoma. All surgical plans and treatment options were significantly affected by the previous arthroscopic procedures. One patient underwent above-the-knee amputation; one patient underwent extra-articular wide resection of the knee, including portal sites with distal femur/total knee reconstruction; one patient underwent rotationplasty, and one patient was treated with therapeutic radiation (no surgery). All patients received chemotherapy. Although intra-articular sarcomas are rare, orthopaedic surgeons must remain vigilant when proceeding with arthroscopic procedures if the clinical history, physical exam, and imaging findings are not perfectly aligned.

Bone Metastases in Patients with Leiomyosarcoma: A Retrospective Analysis of Survival and Surgical Management.

Background: Leiomyosarcomas (LMS) are malignancies with smooth muscle differentiation. Metastasis to the bone is not uncommon. The literature on the clinical course and management of such metastases is limited. Our study describes the clinical course of LMS to the bone, including survival rates, prognostic factors, and surgical management. Methods: We retrospectively reviewed 396 LMS patients presenting at an academic center between 1995 and 2020. We included LMS patients diagnosed with bone metastases and excluded patients with primary LMS of bone. We evaluated survival time with the Kaplan-Meier survival method and used Cox's proportional hazards regression analysis to determine factors associated with survival. Results: Forty-five patients with LMS (11%) had bone metastases. The most common LMS subtypes with bone metastases were uterine (N = 18, 40%) and retroperitoneal (N = 15, 33%). Bone metastasis was not an independent predictor of mortality by Cox regression analysis (HR 1.0, 95% CI: 0.67-1.5). Patients more frequently metastasized to the axial (N = 29, 64%) than to the appendicular (N = 5, 11%) skeleton. Bone was the first site of metastasis in 13 patients (29%). Patients presented with bone metastases at a median of 32.7 months (IQR: 5.2, 62.6) after initial LMS diagnosis. Twelve patients (27%) sustained a pathologic fracture. Twenty (44%) required surgical management, with 30 surgeries total. Three (15%) had a failure of reconstructive constructs. The median overall survival time was 69.7 months (IQR: 43.2, 124.5). There were no associations between the LMS subtype and survival. Pathologic fracture was an independent predictor of mortality by Cox regression analysis (HR 5.4, 95% CI: 1.8-16). Conclusion: The majority of patients with metastatic LMS to bone survive greater than 5 years and frequently require surgical intervention. Extended survival in this patient population should inform fixation and implant choice. No anatomic subtype was associated with risk for bone metastases. Pathologic fracture was associated with worse survival.

Survey of sarcoma surgery principles among orthopaedic oncologists.

BACKGROUND: Surgical principles and techniques used during primary sarcoma excision focus on acquiring negative margins, reducing the risk of local recurrence, and minimizing contamination. These principles and techniques within orthopaedic oncology are not well documented in the literature. No standardized surgical hand-off or approach to education across disciplines on orthopaedic oncology principles and techniques has been published. Currently, education on intraoperative approaches is passed down by oral tradition. OBJECTIVES: Our objective was to survey members of the Musculoskeletal Tumor Society (MSTS) to identify their core principles and practices in orthopaedic oncology. We aimed to 1) provide descriptive analyses of surgeon technique patterns; 2) determine correlations between individual practice patterns; and 3) identify distinct clusters of surgeons on the basis of common practice tendencies. METHODS: A web-based, 16-question survey regarding orthopaedic oncology intraoperative principles and techniques was distributed online to all 349 members of the MSTS in 2021. There were 137 (39%) unique respondents, all of whom completed the entire survey. The 16 survey questions were grouped into 4 key aspects of sarcoma excision: pre-incision, exposure of the mass, delivery of the mass, and closure. The questions inquired about respondent preference on draping, back table setup, instrument use, and intraoperative decision making. These questions were selected on the basis of existing reports, as well as the senior author's experience. We analyzed the responses using 3 methods: 1) descriptive statistics, 2) correlations between question responses, and 3) clustering analysis. We used an artificial intelligence-based clustering algorithm to cluster respondents according to their practice patterns. The results of our correlation analyses are reported as Spearman's rho (ρ) correlation coefficients. RESULTS: Most respondents (mean, 71%; standard deviation, 22%) reported using the described surgical techniques "most of the time" or "in all cases." A strong positive correlation was found between respondents who answered "yes" to both of the following questions: "Do you change your surgical gloves after passing off the tumor specimen?" and "Does your entire surgical team change their gloves after passing off the tumor specimen?" (ρ = 0.88). A moderate positive correlation was found between those who answered "yes" to both of the following questions: "Do you change your surgical gloves after passing off the tumor specimen (i.e., prior to closure)?" and "Do you use new and/or unused surgical instruments for the final closure?" (ρ = 0.60). The cluster analysis identified 3 distinct clusters of respondents. The conservative technique cluster (N = 42) was more likely to answer "yes" to 9 of the 10 questions regarding incision management, consultant team communication, gloving, and instrument use, whereas the permissive technique cluster (N = 41) was more likely to answer "no" to questions regarding gloving, draping, and instrument use. CONCLUSIONS: Our findings indicate that most respondents perform the surveyed techniques, and there is homogeneity in the practice patterns of members of the MSTS; however, we identified distinct clusters of respondents who were significantly more likely to perform certain techniques. These results support establishing a standardized set of intraoperative techniques and formal surgical education regarding intraoperative principles and techniques in orthopaedic oncology.

Injection granuloma mimicking soft tissue sarcoma following seasonal influenza vaccine administration: A case report.

RATIONALE: Soft tissue masses are common within the general population with a minority diagnosed as soft tissue neoplasms. Differing between benign and malignant soft tissue processes can be a challenge given the overlapping clinical and imaging characteristics. We present the case of a 69-year-old female referred to the Orthopaedic Oncology Service for evaluation of a suspected soft tissue sarcoma in the upper arm. PATIENT CONCERNS: She reported a mass localized over the deltoid with associated tenderness 1 month after influenza vaccination. DIAGNOSIS: After thorough consideration of the patient's clinical course, history, advanced imaging, and physical examination, the diagnosis of injection granuloma associated with recent influenza vaccination was considered. INTERVENTIONS: Biopsy was deferred and close interval follow-up with clinical and imaging evaluation revealed a resolving process. OUTCOMES: The patient was followed until complete resolution of all symptoms, which occurred 5 months after initial presentation. LESSONS: It was hypothesized that due the patient's body habitus, the injection contents intended for intramuscular administration remained in the subcutaneous tissues and elicited a granulomatous reaction. This case highlights several important factors for physicians to consider in the work up of suspicious masses for which injection granuloma is on the differential diagnosis.

Indications and outcomes of palliative major amputation in patients with metastatic cancer.

BACKGROUND: Patients with stage IV cancer often experience diminished quality of life and pain. Although palliative amputation (PA) can reduce pain, it is infrequently performed because of the morbidity associated with amputation and the limited life expectancy in this population. Here, we describe the indications for PA in patients with stage IV carcinoma or sarcoma and discuss their clinical courses and outcomes. We hypothesized that PA would be associated with reduced pain and improved quality of life in these patients. METHODS: We retrospectively reviewed medical records of all patients who underwent major amputation (proximal to the ankle or wrist) for metastatic sarcoma or carcinoma from January 1995 to April 2021. We excluded patients who underwent amputation for indications other than palliation. Cox proportional hazards regression analysis was used to determine factors associated with survival after PA. RESULTS: Twenty-six patients underwent PA (11 for carcinoma, 15 for sarcoma). The most common indications for PA were pain (all patients) and fungating tumor (16 patients). PA was the initial surgery in 7 patients. Forequarter amputations were the most common procedure (6 patients). All patients reported reduced pain after PA, with the mean (±standard deviation) visual analog pain score (on a 10-point scale) decreasing from 5.7 ± 2.9 preoperatively to 0.43 ± 1.3 postoperatively (p < 0.001). The mean preoperative ECOG score was 1.9 ± 0.2 compared with 1.3 ± 0.1 postoperatively (p < 0.001). Fourteen patients were fitted for prostheses (6 upper extremity, 8 lower extremity). Two patients had local recurrence, both within 6 months after PA. The mean survival time after PA was 13 ± 12 months, and mean follow-up was 28 ± 29 months. Mean survival time after PA was not significantly different between patients with sarcoma (11 ± 11 months) versus carcinoma (15 ± 14 months) (p = 0.51). Adjuvant chemotherapy was positively associated with survival; no other factors were associated with survival. CONCLUSIONS: PA was associated with significantly reduced pain in all patients with stage IV cancer. PA should be considered for those with intractable pain, fungating tumors, or symptoms that diminish quality of life. LEVEL OF EVIDENCE: Level III.

Iatrogenic Metastasis of Soft-tissue Sarcoma at the Donor Flap Site: Case Report and Proposed Surgical Oncologic Techniques.

An 81-year-old woman with multiply recurrent undifferentiated pleomorphic sarcoma of the foot underwent wide excision and reconstruction with an anterolateral thigh free flap. Six years postoperatively, she developed biopsy-proven recurrence within the harvest site. No other sites of disease were detected on staging workup. The flap site recurrence was attributed to iatrogenic implantation at the time of harvesting. Iatrogenic metastases are thought to be caused by tumor implantation, which may be attributable to cross-contamination from instrumentation and surgical techniques. In the present article, we highlight preventive techniques and oncologic surgical principles intended to reduce the likelihood of iatrogenic metastasis. Increased awareness by all members of the surgical team may prevent this unfortunate complication.

Sagittal plane alignment affects the strength of pin fixation in supracondylar humerus fractures.

ABSTRACT: Closed reduction with percutaneous pin fixation is commonly used to treat pediatric supracondylar humerus fractures. Various pin configurations of varying biomechanical strength have been described. However, to our knowledge, no biomechanical study has focused on pin alignment in the sagittal plane. Our goal was to compare the stability of fixation using 3 different pin constructs: 3 lateral pins diverging in the coronal plane but parallel in the sagittal plane (3LDP), 3 lateral pins diverging in the coronal and sagittal planes (3LDD), and 2 crossed pins (1 medial and 1 lateral).Transverse fractures were made through the olecranon fossa of 48 synthetic humeri, which were then reduced and pinned in the 3LDP, 3LDD, and crossed-pin configurations (16 specimens per group) using 1.6-mm Kirschner wires. The sagittal plane pin spread was significantly greater in the 3LDD group than in the 3LDP group, whereas we found no difference in the coronal plane. Sagittal extension testing was performed from 0° to 20° at 1°/s for 10 cycles using a mechanical torque stand. The torque required to extend the distal fragment 20° from neutral was compared between groups using one-way analysis of variance with multiple comparison post-hoc analysis. P values ≤.05 were considered significant.The 3LDD configuration was more stable than the 3LDP and crossed-pin configurations. The mean torque required to displace the pinned fractures was 5.7 Nm in the 3LDD group versus 4.1 Nm in the 3LDP group and 3.7 Nm in the crossed-pin group (both, P < .01). We found no difference in stability between the 3LDP and crossed-pin groups (P = .45).In a synthetic biomechanical model of supracondylar humerus fracture, sagittal alignment influenced pin construct stability, and greater pin spread in the sagittal plane increased construct stability when using 3 lateral pins. The lateral pin configurations were superior in stability to the crossed-pin configuration.Level of Evidence: Level V.

Changes in U.S. girls' participation in high school sports: implications for injury awareness.

CONTEXT: The number of female athletes has grown exponentially since Title IX. However, little data exists on the proportion of women and girls who play each sport. OBJECTIVE: To quantify changes in female sports participation in high school sports from 1973 to 2018. DESIGN: Retrospective analysis of data from the National Federation of State High School Associations Participation Survey. SETTING: US high schools. PARTICIPANTS: US high school athletes from 1973 to 2018. MAIN OUTCOME MEASURES: Percentage of female participation for each high school sport in 5-year intervals; and changes in rates of participation by player gender and sport at designated intervals. RESULTS: From 1973 to 2018, the percentage of high school sports played by girls increased from 24.2% to 42.9% ([95%CI, 18.6,18.8], p < 0.0001). In the 14 sports included in our study, all had an increase in the percentage of female participation between 1973 and 2018. >80% of the increases occurred between 1973 and 1998 for all sports except lacrosse, ice hockey, football, and wrestling. Between 1998 and 2018, the percentage of girls playing each sport increased by less than 5% in all sports, except for ice hockey (11.5%, 95% CI 11.0, 12.0, p < 0.001) and wrestling (7.1%, 95% CI 6.9, 7.1, p < 0.001). CONCLUSIONS: Girls' participation in high school sports continues to grow not only in numbers but in the types of sports played. Between 1998 and 2018, the greatest increases were noted in ice hockey and wrestling, which had fewer than 1% female participation before 1998. Physicians providing care for female athletes should be aware of these changes and understand the potential injuries associated with these sports.

Sex-based differences in pediatric supracondylar humerus fractures.

Supracondylar humerus (SCH) fractures are reported to be approximately twice as common among boys as among girls. Little is known about sex-associated differences in fracture patterns and complications. We compared the incidence of pediatric SCH fractures, injury mechanism (high-energy or low-energy), fracture subtypes, associated neurologic injuries, and treatment types by patient sex.We reviewed 1231 pediatric SCH fractures treated at 1 center from 2008 to 2017, analyzing sex distributions overall and by year and fracture subtype. We noted patient demographic characteristics, injury mechanisms, neurologic injuries, and treatments (nonoperative or operative). Binomial 2-tailed, chi-squared, and Student's t tests were used for analysis. Multiple logistic regression was performed to assess associations between sex, age, and injury mechanism. Alpha = 0.05.We found no significant difference in the distribution of girls (52%) vs boys (48%) in our sample compared with a binomial distribution (P = .11). Annual percentages of fractures occurring in girls ranged from 46% to 63%, and sex distribution did not change significantly over time. The mean (± standard deviation) age at injury was significantly younger for girls (5.5 ±â€Š2.5 years) than for boys (6.1 ±â€Š2.5 years) (P < .001). High-energy injury mechanism was associated with older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.03-1.06) but not male sex (OR, 1.04; 95% CI, 0.98-1.1). The overall incidence of neurologic injury was 9.5% but boys did not have greater odds of sustaining neurologic injury (OR, 1.03; 95% CI, 1.0-1.1). We found no sex-associated differences in the distribution of Gartland fracture subtypes (P = .13) or treatment type (P = .39).Compared with boys, girls sustain SCH fractures at a younger age. SCH fractures were distributed equally among girls and boys in our sample. Patient sex was not associated with fracture subtype, injury mechanism, neurologic injury, or operative treatment. These findings challenge the perception that SCH fracture is more common in boys than girls.Level III, retrospective study.

Suprascapular nerve entrapment in young kayaker: a case report.

Kayaking has become one of the most popular paddle sports throughout the world. The shoulder is the most commonly injured area of the body among kayaking participants as a result of acute traumatic events and chronic overuse injuries. Therefore, kayaking participants may often seek advice for shoulder problems and there is a scarcity of studies regarding shoulder injuries in this population. In this case report, we present a young male recreational whitewater kayaker with a severe suprascapular nerve (SSN) entrapment who presented with shoulder pain and inability to perform his sport. He was initially evaluated elsewhere and was treated with nonsteroidal anti-inflammatory medications and physical therapy for presumptive diagnosis of subacromial impingement. After 5 months of failed non-operative treatment, the patient sought a second opinion with our group. SSN entrapment diagnosis was confirmed by a thorough careful physical examination, magnetic resonance imaging and electrodiagnostic study. Given the failure of non-operative treatment, the patient was treated with arthroscopic SSN decompression and successfully returned to kayaking without symptoms. While SSN entrapment has been reported in a variety of sports, especially those involving overhead movements, this is the first case report of SSN entrapment reported which impaired participation in kayaking. This case report supports the consideration of SSN entrapment in the differential diagnosis of painful shoulder among kayaking participants and highlights the importance of undressing the patient and examining the posterior shoulder for atrophy, winging or deformity.

Incidence of clinically evident isolated axillary nerve injury in 869 primary anatomic and reverse total shoulder arthroplasties without routine identification of the axillary nerve.

BACKGROUND: It has been suggested that, during primary shoulder arthroplasty, surgeons should identify the axillary nerve through direct visualization, palpation, or the "tug test" to prevent iatrogenic nerve injury. Our goal was to document the rate of isolated axillary nerve injury (IANI) in patients who had undergone primary anatomic total shoulder arthroplasty (TSA) or reverse total shoulder arthroplasty (RTSA) without routine identification of the axillary nerve. METHODS: Data on 869 cases of primary shoulder arthroplasty (338 TSAs and 531 RTSAs) performed by 1 surgeon between 2003 and 2017 were reviewed. Neither the tug test nor identification of the axillary nerve through palpation or visualization was used in any case. The primary outcome was new IANI documented within 3 months after arthroplasty. The frequency of IANI was summarized using point estimates and 95% confidence intervals (CIs). RESULTS: Six cases met the criteria for IANI. The overall incidence of IANI was 0.7% (95% CI, 0.3%-1.4%). The incidence of IANI was 0.3% (95% CI, 0%-1.6%) after TSA and 0.9% (95% CI, 0.3%-2.1%) after RTSA. All IANIs were cases of neurapraxia, and all patients had experienced complete neurologic recovery at last follow-up. CONCLUSION: Complete, permanent IANI resulting from direct surgical trauma during primary shoulder arthroplasty can be avoided without using the tug test or routine identification of the nerve. A low incidence of partial temporary IANI can be expected, which may be related to indirect traction injuries.