Dedifferentiated Chondrosarcoma: Diagnostic Controversies and Emerging Therapeutic Targets.

PURPOSE OF REVIEW: The pathogenesis of dedifferentiated chondrosarcoma is controversial, and no genetic abnormality has consistently been identified in the disease. Focusing on the diagnostic challenges encountered in dedifferentiated chondrosarcoma, the following review aims at summarizing the tumor's active neoplastic pathways while highlighting therapeutic modalities that could potentially be explored to enhance patient survivorship. RECENT FINDINGS: Owing to the challenging examination of small needle biopsy sampling as well as the disease's overlapping morphological and immunohistochemical features with other bone and soft-tissue sarcomas, the diagnosis of dedifferentiated chondrosarcoma can be problematic. While combined doxorubicin- and cisplatin-based regimens remain the first-line systemic chemotherapy in the disease, ~50% of tumors carry EXT1/2 or IDH1/2 mutations, advancing EXT or IDH inhibitors as potential alternative therapies, respectively. Despite systemic chemotherapy, dedifferentiated chondrosarcoma remains an aggressive tumor with dismal prognosis and limited survival. A multidisciplinary collaboration across multiple cancer centers is warranted to yield an accurate diagnosis, understand the disease's underlying pathogenesis, develop adequate treatment, and improve patient survivorship.

A Comparison Between 3 Functional Hip Scores for Evaluation of the Pediatric Hip.

BACKGROUND: This investigation aimed to determine the degree of correlation among 3 functional scales for evaluating the hip in pediatric patients and determine the correlation between measures of global function and outcome. METHODS: We performed a prospective study of 173 consecutive patients (M age = 13 ± 3 y) being followed for developmental dysplasia of the hip (n = 122, 71%), slipped capital femoral epiphysis (n = 31, 18%), or Legg-Calve-Perthes disease (n = 20, 12%). We evaluated patients clinically, and we compiled scores for the Iowa Hip Score (IHS), Harris Hip Score (HHS), and Children's Hospital Oakland Hip Evaluation Scale (CHOHES). Patients concomitantly completed the Pediatric Outcomes Data Collection Instrument (PODCI) at the same clinic visit. We assessed Global Functioning Scale the and the Sports and Physical Functioning Core Scale of the PODCI. We determined the degree of correlation between the functional hip scales and between each scale and the PODCI scales using Spearman rank correlation coefficients. RESULTS: The correlations between the IHS, HHS, and CHOHES scores were robust (IHS and HHS ρ = 0.991; IHS and CHOHES ρ = 0.933; HHS and CHOHES ρ = 0.938; all P < 0.001). The correlation between the Global Functioning Scale of the PODCI and the 3 hip scores was ρ = 0.343 for the IHS, ρ = 0.341 for the HHS, and ρ = 0.352 for the CHOHES (all P < 0.001). The correlation between the sports and physical functioning core scale of the PODCI and the 3 hip scores was ρ = 0.324 for the IHS, ρ = 0.329 for the HHS, and ρ = 0.346 for the CHOHES (all P < 0.001). CONCLUSIONS: In a pediatric population with diverse hip pathology, there was a very strong correlation between scores on the IHS, HHS, and CHOHES. However, none of these 3 most commonly used hip scores correlated strongly with the global functioning scale or sports and physical functioning core scale of the PODCI. The most frequently used scores to determine the outcome of pediatric patients with hip pathology correlate strongly with each other but do not necessarily relate to global functional results. LEVEL OF EVIDENCE: Level IV.

Effect of a Protocol to Reduce Radiographic Imaging in Pediatric Patients With Suspected Fractures.

BACKGROUND: Children with suspected fractures are typically evaluated with multiple x-rays. This approach can add time, discomfort, and radiation exposure without clinical benefit. The purpose of this study was to determine whether a focused radiographic protocol could reduce the number of x-rays performed without missing any fractures. METHODS: Pediatric patients presenting at 2 sites within an academic medical center [urgent care (UC) and the emergency department(ED)] for a suspected fracture were identified. There were 495 patients (UC, 409; ED, 86) over a 3-month period. A retrospective chart review was performed to characterize the standard x-rays performed. Using this data, a simplified protocol was developed and distributed. Subsequently, 333 patients (UC, 259; ED, 74) were evaluated over the same period 1-year later. The main outcome measures included the final diagnosis, the total number of x-rays, the number of anatomic areas imaged, visit length, and the time for additional trips to radiology. Charts were reviewed to identify any missed injuries. Welch 2-sample t tests and Fisher exact tests were used for statistical analysis. RESULTS: After implementing the radiographic protocol, there was a significant reduction in the number of x-ray views, 3.4 versus 5.1 ( P <0.001). There was a decrease in imaging of multiple anatomic areas with the largest reduction occurring in patients presenting with elbow injuries (9% vs. 44%, P <0.001). No difference was found in the rate of patients sent back to radiology (6% vs. 7%, P =0.67). However, among patients presenting with outside imaging, significantly fewer were sent to radiology for additional x-rays (29% vs. 50%, P <0.01). CONCLUSION: A simple radiographic protocol for evaluating pediatric patients with suspected fractures safely led to a decrease in the overall number of x-rays without missing any injuries. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Impact of tranexamic acid on blood loss and transfusion rate in children with cerebral palsy undergoing hip reconstruction with two or more osteotomies.

PURPOSE: Tranexamic acid (TXA), a synthetic lysine analogue, has been used in orthopedic procedures to limit blood loss and prevent allogeneic blood transfusions. However, data are scarce on its use in hip reconstruction of patients with cerebral palsy (CP). This study examines the effect of TXA on patients with CP undergoing hip reconstruction with at least two osteotomies. METHODS: This is a single-center, retrospective study of patients with CP who underwent hip reconstruction with two or more osteotomies from January 2013 to April 2019. There were 43 patients, with a mean age of 9.9 years. Age, procedure, preoperative and postoperative hemoglobin/hematocrit, estimated blood loss (EBL), transfusions and length of stay were recorded. The patients were split into the following two groups: 24 patients who had received intraoperative TXA and 19 who had not. RESULTS: Age, EBL, mean preoperative and postoperative hemoglobin or hematocrit, preoperative to postoperative hematocrit drop, and length of stay were similar for the two groups (p > 0.05). The risk for intraoperative transfusion (21 vs. 17%), postoperative transfusion (26 vs. 8%), and any transfusion (42 vs. 21%) appeared to be greater in the group that did not receive TXA, but this difference did not achieve statistical significance. CONCLUSION: This pilot study shows patients with CP undergoing hip reconstruction with two or more osteotomies; the use of TXA, while not statistically significant, shows a trend toward a decreased need for allogeneic blood transfusion.

Which Bone-Modifying Agent is Associated with Better Outcomes in Patients with Skeletal Metastases from Lung Cancer? A Systematic Review and Network Meta-analysis.

BACKGROUND: Lung cancer is one of the most commonly diagnosed cancers and is the leading cause of cancer-related deaths. Metastatic bone disease occurs in 20% to 40% of patients with lung cancer, and these patients often present with pain or skeletal-related events (SREs) that are associated with decreased survival. Bone-modifying agents such as denosumab or bisphosphonates are routinely used; however, to our knowledge, there has been no quantitative synthesis of randomized controlled trial data to determine the most effective pharmacologic treatment of metastatic bone disease because of lung cancer. QUESTIONS/PURPOSES: We aimed to perform a network meta-analysis of randomized trials to identify the bone-modifying agent that is associated with the (1) highest overall survival, (2) longest time to SRE, (3) lowest SRE incidence, and (4) greatest likelihood of pain resolution. METHODS: We conducted our study according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol and pre-registered the analysis on PROSPERO (ID: CRD42019124364). We performed a librarian-assisted search of MEDLINE, PubMed, EMBASE, Cochrane Library, and Chinese databases including China National Knowledge Infrastructure and Wanfang Data. We included randomized controlled trials reporting outcomes specifically for patients with lung cancer treated with a bisphosphonate or denosumab. SREs included pathologic fractures, spinal cord compression, hypercalcemia of malignancy, or pain resulting in surgical intervention or radiation therapy. We excluded trials exclusively reporting surrogate outcomes such as changes in bone turnover markers. Screening, data extraction, risk of bias evaluation, and Grading of Recommendations Assessment, Development, and Evaluation evaluations were performed in duplicate. We included 131 randomized controlled trials that evaluated 11,105 patients with skeletal metastases from lung cancer. The network meta-analysis was performed using a frequentist model and the R statistical software. Results are reported as relative risks or mean differences, and the I2 value is reported for heterogeneity. The P-score, a measure of ranking certainty that accounts for standard error, is reported for each outcome. Heterogeneity in the network was considered moderate for overall survival and time to SRE, mild for the incidence of SRE, and low for pain resolution. RESULTS: For overall survival, denosumab was ranked above zoledronic acid and estimated to confer a mean of 3.3 months (95% CI 0.3-6.3) of increased overall survival compared with untreated patients (P-score = 89%). For the time to SRE, denosumab was ranked first with a mean of 9.1 additional SRE-free months (95% CI 6.7-11.5) compared with untreated patients (P-score = 99%), while zoledronic acid conferred an additional 4.8 SRE-free months (95% CI 3.6-6.1). Reduction in the incidence of SREs was not different between patients treated with denosumab (relative risk 0.54; 95% CI 0.33-0.87) and those treated with zoledronic acid (relative risk 0.56; 95% CI 0.46-0.67). Patients treated with the combination of ibandronate and systemic therapy were more likely to experience successful pain resolution than untreated patients (relative risk 2.4; 95% CI 1.8-3.2). CONCLUSION: In this comprehensive synthesis of all available randomized controlled trial evidence guiding the pharmacologic treatment of bone metastases from lung cancer, denosumab was ranked above zoledronic acid for overall survival and time to SRE and was not different for reducing the incidence of SRE. Both were superior to no treatment for each of these outcomes. Given this, we encourage physicians to consider the use of denosumab or zoledronic acid in treating this patient population. The combination of ibandronate and systemic therapy was the most effective at reducing pain because of metastases. No cost-effectiveness analysis has yet been performed for denosumab and zoledronic acid on patients with metastatic lung cancer, and this represents an avenue for future research. LEVEL OF EVIDENCE: Level I, therapeutic study.

What Are the Rate and Risk Factors for Developing a Complication With the Pavlik Method for the Treatment of Hip Dysplasia?

BACKGROUND: The Pavlik method for the treatment of developmental dysplasia of the hip (DDH) has been proven successful for over 85 years. The high success rate and reproducibility have made it the mainstay of treatment. METHODS: We performed a retrospective cohort study of patients with DDH treated with the Pavlik method between September 2016 and August 2018 with at least 24 months of follow up in a single academic center. We excluded patients with neuromuscular conditions, teratologic dislocations, and arthrogryposis. We identified and included a total of 307 patients in the analysis. There were 66 patients with dysplasia, 97 with instability, and 144 with a dislocation. Data collected included age at initiation of the Pavlik method, diagnosis (isolated dysplasia, subluxation, or dislocation), duration of treatment, follow up duration and any complication. At final follow up, anteroposterior radiographs of the pelvis were used to determine the Severin classification. RESULTS: Major complications were proximal femoral growth disturbance (5.8%) and femoral nerve palsy (0.98%). Multivariate analysis showed that an initial diagnosis of a dislocated hip (odds ratio, 2.20; P<0.01), was significantly associated with developing a complication. At final follow up, we found Severin type I or II radiographic findings in 100% of patients with dysplasia, 95% of patients with instability and 54% of patients with dislocation (P=0.001). CONCLUSIONS: Complications are not entirely uncommon when the Pavlik method is used for the treatment of DDH. The overall rate of major complications was 7%. The Pavlik method is safe, and independent risk factors for complications were being over 5 months of age and having a dislocated hip at initial presentation. LEVEL OF EVIDENCE: Level IV-cohort study.

The Validity of Patient-reported Outcome Measurement Information System (PROMIS) Parent Proxy Instruments to Assess Function in Children With Talipes Equinovarus.

BACKGROUND: Idiopathic talipes equinovarus (ITEV) is a prevalent structural deformity of the foot and ankle in children. The disease-specific instrument (DSI) has commonly been used as an outcomes metric in these patients. The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed to examine the quality of life across various medical conditions. PROMIS has been validated for multiple conditions; however, no studies have evaluated the use of the PROMIS in children with ITEV. METHODS: A prospective analysis was performed whereby the 2 questionnaires were mailed out to the parents of 91 patients, aged 5 to 17 years, with ITEV. Construct validity of the PROMIS Parent Proxy Profile short forms version was assessed by comparing its domains of Mobility, Fatigue, Pain Interference, and Pain Intensity to the DSI Function domain and PROMIS domains of Anxiety, Depressive Symptoms, Peer Relationships, and Pain Intensity to DSI Satisfaction domain. RESULTS: Thirty-one complete responses (34% response rate) were returned. The patients' current mean age was 8.8 years, 7 were female individuals, and 12 had unilateral ITEV. Bivariate correlation analysis, using Spearman correlation coefficients, demonstrated a moderate positive correlation between the DSI Function domain and the PROMIS Mobility domain (rs=0.52) and a moderate negative correlation between the DSI Function domain and the PROMIS Pain Interference domain (rs=-0.56), as well as the PROMIS Pain Intensity domain (rs=-0.75). A fair negative correlation (rs=-0.38) with PROMIS Fatigue domain was found. Correlations between the DSI Satisfaction domain and the PROMIS domains were fair or had little relationship. CONCLUSIONS: These results provide support for the validity of the PROMIS Mobility, Pain Interference, and Pain Intensity domains in this population, however there are no items in PROMIS that can assess overall satisfaction, as with the DSI. LEVEL OF EVIDENCE: Level II-prospective comparative study.

Comparing the 30-Day Risk of Venous Thromboembolism and Bleeding in Simultaneous Bilateral vs Unilateral Total Knee Arthroplasty.

BACKGROUND: Simultaneous bilateral total knee arthroplasty (SBTKA) may offer certain benefits; however, its overall safety is still disputed. This study aimed at comparing the risk of thromboembolism and bleeding in patients who underwent SBTKA vs unilateral total knee arthroplasty (TKA). METHODS: The American College of Surgeons National Surgical Quality Improvement Program database from 2008 to 2015 was used to investigate the short-term postoperative complications and their risk factors following SBTKA as compared to unilateral TKA. Demographics, comorbidities, and 30-day outcomes were analyzed. Complications with an increased incidence following SBTKA were stratified to identify subgroups of patients at high risk. RESULTS: A total of 155,022 patients were identified, of which 150,581 underwent unilateral TKA and 4441 underwent SBTKA. The SBTKA group was found to be at a higher risk of venous thromboembolism (VTE), bleeding, and composite morbidity. Stratification analysis revealed that SBTKA subgroups at higher risk of VTE include patients of black or Asian origin, obese patients, and those who underwent anesthesia other than general or spinal/epidural. SBTKA subgroups at higher risk of bleeding include patients older than 85 years, those with race other than white, underweight and obese patients, and patients who underwent anesthesia other than spinal/epidural. Although none of the subgroups were protected from bleeding, patients who underwent spinal/epidural anesthesia had a lower risk of bleeding compared to other types of anesthesia. CONCLUSION: SBTKA confers an increased risk of postoperative VTE, bleeding, and composite morbidity at 30 days, with no increase in mortality.

Comparison of Early Adverse Events After Operative Treatment of Bimalleolar and Trimalleolar Fractures Versus Pilon Fractures.

Ankle fractures requiring open reduction and internal fixation vary in severity from unimalleolar fractures to bimalleolar/trimalleolar (BT) fractures to pilon fractures. Consequently, the postoperative outcomes with these surgeries can vary. Most previous studies of these injuries had small sample sizes, studied a single risk factor or adverse event, or did not compare different injuries by severity. The purpose of the present study was to describe and compare the patient characteristics and postoperative outcomes of 2 high-energy ankle fractures: BT and pilon fractures. The relevant patients were identified from the American College of Surgeons National Surgical Quality Improvement Program database using the Current Procedural Terminology codes for BT and pilon fractures. Patient demographics, characteristics, comorbidities, and 30-day mortality and adverse events were recorded and compared between the 2 types of ankle fractures. More than 45% of patients with these fracture types were aged 40 to 65 years. Pilon fractures occurred more frequently in younger patients, were more likely to occur in men, required a longer hospital stay and operative time, were less likely to occur in patients with a body mass index of >30 kg/m2, and conferred a greater risk of wound complications (odds ratio 1.76; p = .048) compared with BT fractures. The findings from the present study help us understand the differences in patient characteristics and potential early adverse events after open reduction and internal fixation of BT fractures versus pilon fractures.

Preoperative Pneumonia and Postoperative Venous Thrombosis: A Cohort Study of 427,656 Patients Undergoing Major General Surgery.

BACKGROUND: The literature is sparse regarding the association between pneumonia and venous thrombosis in surgical patients. The aim of this study was to investigate the risk of postoperative venous thrombosis in patients who fit the criteria for preoperative pneumonia using data from the ongoing American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database while adjusting for potential confounders. METHODS: This is a cohort study using data from the ACS NSQIP database participating sites from 2008 (211 sites) and 2009 (237 sites). 427,656 patients undergoing major general surgery were included. The 30-day risk of postoperative venous thrombosis including deep vein thrombosis (DVT) and pulmonary embolism (PE) was evaluated in patients with preoperative pneumonia diagnosed before undergoing major general surgery. RESULTS: Patients with preoperative pneumonia had a higher incidence of both 30-day DVT and PE than patients without preoperative pneumonia. After adjusting for all potential confounders, the effect estimates for the association between preoperative pneumonia and venous thrombosis were DVT, OR: 1.67 (95% CI 1.32-2.11) and PE, OR: 2.18 (95% CI 1.48-3.22). CONCLUSIONS: A large, multicenter database of surgical patients showed that preoperative pneumonia may increase risk for developing venous thrombosis. This adds to our understanding of risk factors for venous thrombosis and suggests a potential benefit of diagnosing preoperative pneumonia in patients undergoing major general surgery.

Back pain: A puzzle in children.

Back pain in children is underdiagnosed and increases incidence in adolescence. A systematic approach can diagnose the most common causes: trauma, structural deformities, inflammatory diseases, infection and malignancy.

The Association of Anemia and Its Severity with Cardiac Outcomes and Mortality After Total Knee Arthroplasty in Noncardiac Patients.

BACKGROUND: The purpose of this study is to assess whether an association exists between preoperative anemia and postoperative cardiac events or death in patients undergoing unilateral primary total knee arthroplasty (TKA) with no prior cardiac history. METHODS: Data from the 2008-2012 American College of Surgeons National Surgical Quality Improvement Program database were analyzed. Patients aged ≥18 years undergoing unilateral primary TKA were included. We divided the patients into 4 groups: no anemia, any anemia, mild anemia, and moderate-severe anemia. Associations between anemia and different characteristics as well as cardiac outcomes and death were studied, after adjusting for all potential confounders. RESULTS: In the nonanemic group, the occurrence of myocardial infarction, cardiac arrest, and death were 61 of 34,661 (0.18%), 23 of 34,661 (0.07%), and 30 of 34,661 (0.09%), respectively. The numbers in the anemia group were 23 of 6673 (0.34%), 9 of 6673 (0.13%), and 14 of 6673 (0.21%). These were not statistically different. The anemic group had higher odds for respiratory and renal morbidities and for receiving transfusions. CONCLUSION: We found no association between preoperative anemia or its severity and myocardial infarction, cardiac arrest, or death up to 30 days postoperatively. This could potentially lower the bar for safe preoperative hematocrit levels for elective TKA, theoretically increasing the percentage of anemic patients undergoing the procedure. This, however, is at the expense of potential respiratory and renal insults.

Cortical bone invasion in non-transfusion-dependent thalassemia: tumefactive extramedullary hematopoiesis reviewed.

OBJECTIVE OF THE STUDY: To assess the prevalence of cortical bone invasion (CBI) with secondary extramedullary hematopoiesis (EMH) in patients with non-transfusion-dependent thalassemia (NTDT), to determine its predilection sites on thoracic and abdominal imaging, to determine whether there is an association between various clinical and hematological parameters, and to evaluate its various findings mainly on magnetic resonance imaging (MRI), in addition to computed tomography (CT) scans. MATERIALS AND METHODS: This is a retrospective cohort study of 57 patients with NTDT imaged by CT or MRI. Both clinical and laboratory data were gathered. An imaging scoring system was used to describe the appearance of CBI by MRI. RESULTS: Twenty-seven patients (47.4 %) were found to have CBI and EMH with the most common location being the thoracic spine. Splenectomy and lower hemoglobin level were found to be independent risk factors for its development. Most lesions were homogenous (70 %), had predominant red marrow signal (67 %), and well-defined margins (89 %). CONCLUSION: CBI and secondary tumefactive EMH are common findings in patients with NTDT, with distinct imaging and clinical characteristics. An increased risk was seen in patients with splenectomy and lower hemoglobin. The imaging scoring system described is helpful in diagnosing and describing this entity, hence precluding unnecessary biopsies.

Retrograde Percutaneous Drilling for Osteochondritis Dissecans of the Head of the Talus: Case Report and Review of the Literature.

Osteochondral lesions of the talus might be a more common cause of pain than previously recognized, especially among those involved in athletic activities. However, the location of an osteochondral lesion on the talar head is much less common than such lesions localized to the dome of the talus and can pose diagnostic difficulties. We present the case of a 14-year-old soccer player who complained of longstanding pain in his left foot. After unsuccessful conservative treatment consisting of rest and bracing, he was ultimately treated with retrograde percutaneous drilling of the talar head performed by a medial approach. This was followed by casting and non-weightbearing for 6 weeks, after which physical therapy was undertaken. He was able to return to full activity and remained asymptomatic during a 5-year observation period. Although rare, osteochondritis dissecans of the talar head should be considered in young athletes with persistent foot pain that is unresponsive to reasonable therapy.

Bilateral Achilles Tendon Ruptures Associated With Ciprofloxacin Use in the Setting of Minimal Change Disease: Case Report and Review of the Literature.

Fluoroquinolones are widely used antibiotics; however, numerous side effects have been reported in published studies, including a spectrum of tendinopathies, affecting numerous anatomic sites. Several risk factors have been identified, including advanced age (>60 years), corticosteroid use, renal failure or dialysis, female sex, and nonobesity. We present the case of an elderly male with minimal change disease treated with glucocorticoids and acute kidney injury, who sustained spontaneous nontraumatic bilateral Achilles tendon tears 4 days after initiating ciprofloxacin.

Intramuscular myxoma of the tibialis anterior muscle First report in the English literature.

Intramuscular myxoma is a rare entity in itself, and while it has been described in several locations in the body, its presence in the tibialis anterior muscle has only been reported once in the literature. In this case report, we present, to our knowledge, the first case of an intramuscular myxoma in the tibialis anterior muscle in the English literature, which was successfully managed with wide surgical resection.

Outcomes of treatment for developmental dislocation of the hip when the Pavlik method has failed.

OBJECTIVES: Despite the success rate of the Pavlik method in the treatment of developmental dislocation of the hip, there is a subset of hips that do not reduce with harness use. The purpose of this study was to determine the outcomes after closed reduction (CR), open reduction (OR) and combined open reduction and pelvic osteotomy (OR+PO) in patients with infantile hip dislocations who initially failed the Pavlik method. METHODS: This was a retrospective cohort study of patients with infantile hip dislocations who failed the Pavlik method and subsequently underwent a secondary procedure for persistent hip dislocation. The primary outcome measure was the Severin classification of the involved hip 3 years after the secondary procedure. Other outcomes assessed included rates of redislocation, residual acetabular dysplasia and proximal femoral growth disturbance. RESULTS: Twenty-three patients were included; seven subsequently underwent CR, three underwent isolated OR and 13 proceeded directly to OR+PO. The overall successful outcome rate at final follow-up (as determined by radiographic Severin class I or II) was 11/23 (48%). However, patients undergoing OR+PO had significantly higher rates of successful outcomes (77%) compared with CR (15%) and OR (0%), P  < 0.05. The rate of residual acetabular dysplasia and proximal femoral growth disturbance was significantly lower in patients treated with OR+PO compared with CR and isolated OR, P  < 0.05. CONCLUSION: Patients with dislocated hips who failed Pavlik harness treatment had better radiographic outcomes 3 years after OR+PO in comparison to patients undergoing CR or isolated OR.

Diffuse-Type Tenosynovial Giant Cell Tumor An Update of Current Management Strategies.

Diffuse-type giant cell tumor (Dt-GCT), formerly known as pigmented villonodular synovitis, is the more aggressive entity belonging to the spectrum of benign proliferative lesions of synovial origin that may affect the joints, bursae, and tendon sheaths. Diffuse-type giant cell tumor's importance stems from its local aggressiveness and sequelae if left untreated. This review briefly describes Dt-GCT's clinical features, its imaging and pathology findings, and provides an extensive discussion of its available treatments. The management approaches of Dt-GCT can be divided into surgical management and non-surgical management, which includes radiation therapy or more novel molecular and biologic therapies. We also present an algorithm based on disease presentation and site involved to guide treatment.

Masses in the extensor mechanism of the knee: an unusual presentation of gout.

Tophaceous gout presenting as a soft tissue mass in an unusual location can pose a diagnostic challenge for radiologists. Tophi sometimes occur in a variety of unusual anatomic locations making them difficult to distinguish from tumors such as sarcomas. We report two cases of gout in the extensor mechanism of the knee, with imaging findings that were initially concerning for a neoplasm. One mass occurred in the patellar tendon and the other mass involved the quadriceps tendon. Both lesions had enigmatic imaging findings and to arrive at a definitive diagnosis, incisional biopsies were performed.

Correlation of non-mass-like abnormal MR signal intensity with pathological findings surrounding pediatric osteosarcoma and Ewing's sarcoma.

OBJECTIVE: The aim of this work was to determine the role of MRI in interpreting abnormal signals within bones and soft tissues adjacent to tumor bulk of osteosarcoma and Ewing's sarcoma in a pediatric population by correlating MR findings with histopathology. MATERIALS AND METHODS: Thirty patients met the inclusion criteria, which included (1) osteosarcoma or Ewing's sarcoma, (2) MR studies no more than 2 months prior to surgery, (3) presence of abnormal MR signal surrounding the tumor bulk, (4) pathological material from resected tumor. The patients received standard neoadjuvant chemotherapy. Using grid maps on gross pathology specimens, the abnormal MR areas around the tumor were matched with the corresponding grid sections. Histopathology slides of these sections were then analyzed to determine the nature of the regions of interest. The MR/pathological correlation was evaluated using Mann-Whitney U test and Fisher's exact test. RESULTS: Twenty-seven patients had osteosarcoma and three patients had Ewing's sarcoma. Of the studied areas, 17.4% were positive for tumor (viable or necrotic). There was no statistically significant correlation between areas positive for tumor and age, gender, signal extent and intensity on MRI, or tissue type. There was, however, a statistically significant correlation between presence of tumor and the appearance of abnormal soft tissue signals. A feathery appearance correlated with tumor-negative areas whereas a bulky appearance correlated with tumor-positive regions. CONCLUSIONS: MR imaging is helpful in identifying the nature of abnormal signal areas surrounding bone sarcomas that are more likely to be tumor-free, particularly when the signal in the soft tissues surrounding the tumor is feathery and edema-like in appearance.