Nineteen-Year-Old Woman with Symptomatic Intramuscular Thigh Hemangioma-Radiographic Changes and Management: A Case Report.

CASE: We report a case of an intramuscular thigh hemangioma in a 19-year-old woman with a several year history of atraumatic thigh pain. Radiographs obtained by her primary care physician demonstrated periosteal bone reaction, prompting referral to Orthopaedic Oncology department. The patient had successful symptomatic management with propranolol. CONCLUSION: The case highlights the diagnosis and potential treatments. In a stepwise approach to care for symptomatic benign vascular lesions, propranolol has been a proven therapeutic option and may be a useful first-line therapy for symptomatic hemangiomas.

What are the Trends in Racial Diversity Among Orthopaedic Applicants, Residents, and Faculty?

BACKGROUND: Orthopaedic surgery has recruited fewer applicants from underrepresented in medicine (UIM) racial groups than many other specialties, and recent studies have shown that although applicants from UIM racial groups are competitive for orthopaedic surgery, they enter the specialty at lower rates. Although previous studies have measured trends in orthopaedic surgery applicant, resident, or attending diversity in isolation, these populations are interdependent and therefore should be analyzed together. It is unclear how racial diversity among orthopaedic applicants, residents, and faculty has changed over time and how it compares with other surgical and medical specialties. QUESTIONS/PURPOSES: (1) How has the proportion of orthopaedic applicants, residents, and faculty from UIM and White racial groups changed between 2016 and 2020? (2) How does representation of orthopaedic applicants from UIM and White racial groups compare with that of other surgical and medical specialties? (3) How does representation of orthopaedic residents from UIM and White racial groups compare with that of other surgical and medical specialties? (4) How does representation of orthopaedic faculty from UIM and White racial groups compare with that of other surgical and medical specialties? METHODS: We drew racial representation data for applicants, residents, and faculty between 2016 and 2020. Applicant data on racial groups was obtained for 10 surgical and 13 medical specialties from the Association of American Medical Colleges Electronic Residency Application Services report, which annually publishes demographic data on all medical students applying to residency through Electronic Residency Application Services. Resident data on racial groups were obtained for the same 10 surgical and 13 medical specialties from the Journal of the American Medical Association Graduate Medical Education report, which annually publishes demographic data on residents in residency training programs accredited by the Accreditation Council for Graduate Medical Education. Faculty data on racial groups were obtained for four surgical and 12 medical specialties from the Association of American Medical Colleges Faculty Roster United States Medical School Faculty report, which annually publishes demographic data of active faculty at United States allopathic medical schools. UIM racial groups include American Indian or Alaska Native, Black or African American, Hispanic or Latino, and Native American or Other Pacific Islander. Chi-square tests were performed to compare representation of UIM and White groups among orthopaedic applicants, residents, and faculty between 2016 and 2020. Further, chi-square tests were performed to compare aggregate representation of applicants, residents, and faculty from UIM and White racial groups in orthopaedic surgery to aggregate representation among other surgical and medical specialties with available data. RESULTS: The proportion of orthopaedic applicants from UIM racial groups increased between 2016 to 2020 from 13% (174 of 1309) to 18% (313 of 1699, absolute difference 0.051 [95% CI 0.025 to 0.078]; p < 0.001). The proportion of orthopaedic residents (9.6% [347 of 3617] to 10% [427 of 4242]; p = 0.48) and faculty (4.7% [186 of 3934] to 4.7% [198 of 4234]; p = 0.91) from UIM racial groups did not change from 2016 to 2020. There were more orthopaedic applicants from UIM racial groups (15% [1151 of 7446]) than orthopaedic residents from UIM racial groups (9.8% [1918 of 19,476]; p < 0.001). There were also more orthopaedic residents from UIM groups (9.8% [1918 of 19,476]) than orthopaedic faculty from UIM groups (4.7% [992 of 20,916], absolute difference 0.051 [95% CI 0.046 to 0.056]; p < 0.001). The proportion of orthopaedic applicants from UIM groups (15% [1151 of 7446]) was greater than that of applicants to otolaryngology (14% [446 of 3284], absolute difference 0.019 [95% CI 0.004 to 0.033]; p = 0.01), urology (13% [319 of 2435], absolute difference 0.024 [95% CI 0.007 to 0.039]; p = 0.005), neurology (12% [1519 of 12,862], absolute difference 0.036 [95% CI 0.027 to 0.047]; p < 0.001), pathology (13% [1355 of 10,792], absolute difference 0.029 [95% CI 0.019 to 0.039]; p < 0.001), and diagnostic radiology (14% [1635 of 12,055], absolute difference 0.019 [95% CI 0.009 to 0.029]; p < 0.001), and it was not different from that of applicants to neurosurgery (16% [395 of 2495]; p = 0.66), plastic surgery (15% [346 of 2259]; p = 0.87), interventional radiology (15% [419 of 2868]; p = 0.28), vascular surgery (17% [324 of 1887]; p = 0.07), thoracic surgery (15% [199 of 1294]; p = 0.94), dermatology (15% [901 of 5927]; p = 0.68), internal medicine (15% [18,182 of 124,214]; p = 0.05), pediatrics (16% [5406 of 33,187]; p = 0.08), and radiation oncology (14% [383 of 2744]; p = 0.06). The proportion of orthopaedic residents from UIM groups (9.8% [1918 of 19,476]) was greater than UIM representation among residents in otolaryngology (8.7% [693 of 7968], absolute difference 0.012 [95% CI 0.004 to 0.019]; p = 0.003), interventional radiology (7.4% [51 of 693], absolute difference 0.025 [95% CI 0.002 to 0.043]; p = 0.03), and radiation oncology (7.9% [289 of 3659], absolute difference 0.020 [95% CI 0.009 to 0.029]; p < 0.001), and it was not different from UIM representation among residents in plastic surgery (9.3% [386 of 4129]; p = 0.33), urology (9.7% [670 of 6877]; p = 0.80), dermatology (9.9% [679 of 6879]; p = 0.96), and diagnostic radiology (10% [2215 of 22,076]; p = 0.53). The proportion of orthopaedic faculty from UIM groups (4.7% [992 of 20,916]) was not different from UIM representation among faculty in otolaryngology (4.8% [553 of 11,413]; p = 0.68), neurology (5.0% [1533 of 30,871]; p = 0.25), pathology (4.9% [1129 of 23,206]; p = 0.55), and diagnostic radiology (4.9% [2418 of 49,775]; p = 0.51). Compared with other surgical and medical specialties with available data, orthopaedic surgery had the highest proportion of White applicants (62% [4613 of 7446]), residents (75% [14,571 of 19,476]), and faculty (75% [15,785 of 20,916]). CONCLUSION: Orthopaedic applicant representation from UIM groups has increased over time and is similar to that of several surgical and medical specialties, suggesting relative success with efforts to recruit more students from UIM groups. However, the proportion of orthopaedic residents and UIM groups has not increased accordingly, and this is not because of a lack of applicants from UIM groups. In addition, UIM representation among orthopaedic faculty has not changed and may be partially explained by the lead time effect, but increased attrition among orthopaedic residents from UIM groups and racial bias likely also play a role. Further interventions and research into the potential difficulties faced by orthopaedic applicants, residents, and faculty from UIM groups are necessary to continue making progress. CLINICAL RELEVANCE: A diverse physician workforce is better suited to address healthcare disparities and provide culturally competent patient care. Representation of orthopaedic applicants from UIM groups has improved over time, but further research and interventions are necessary to diversify orthopaedic surgery to ultimately provide better care for all orthopaedic patients.

Total Hip and Knee Arthroplasty Surgery in the Morbidly Obese Patient: A Critical Analysis Review.

¼: Obesity, defined as body mass index (BMI) ≥30, is a serious public health concern associated with an increased incidence of stroke, diabetes, mental illness, and cardiovascular disease resulting in numerous preventable deaths yearly. ¼: From 1999 through 2018, the age-adjusted prevalence of morbid obesity (BMI ≥40) in US adults aged 20 years and older has risen steadily from 4.7% to 9.2%, with other estimates showing that most of the patients undergoing hip and knee replacement by 2029 will be obese (BMI ≥30) or morbidly obese (BMI ≥40). ¼: In patients undergoing total joint arthroplasty (TJA), morbid obesity (BMI ≥40) is associated with an increased risk of perioperative complications, including prosthetic joint infection and mechanical failure necessitating aseptic revision. ¼: The current literature on the role that bariatric weight loss surgery before TJA has on improving surgical outcomes is split and referral to a bariatric surgeon should be a shared-decision between patient and surgeon on a case-by-case basis. ¼: Despite the increased risk profile of TJA in the morbidly obese cohort, these patients consistently show improvement in pain and physical function postoperatively that should be considered when deciding for or against surgery.

Treating Hepatitis C Prior to Total Hip Arthroplasty is Cost-effective: A Markov Analysis.

BACKGROUND: Patients infected with the hepatitis C virus (HCV) have high complication rates following total hip arthroplasty (THA). Advances in HCV therapy now enable clinicians to eradicate the disease; however, its cost-effectiveness from an orthopaedic perspective remains to be demonstrated. We sought to conduct a cost-effectiveness analysis comparing no therapy to direct-acting antiviral (DAA) therapy prior to THA among HCV-positive patients. METHODS: A Markov model was utilized to evaluate the cost-effectiveness of treating HCV with DAA prior to THA. The model was powered with event probabilities, mortality, cost, and quality-adjusted life year (QALY) values for patients with and without HCV that were obtained from the published literature. This included treatment costs, successes of HCV eradication, incidences of superficial or periprosthetic joint infection (PJI), probabilities of utilizing various PJI treatment modalities, PJI treatment success/failures, and mortality rates. The incremental cost-effectiveness ratio was compared to a willingness-to-pay threshold of $50,000/QALY. RESULTS: Our Markov model indicates that in comparison to no therapy, DAA prior to THA is cost-effective for HCV-positive patients. THA in the setting of no therapy and DAA added 8.06 and 14.39 QALYs at a mean cost of $28,800 and $115,800. The incremental cost-effectiveness ratio associated with HCV DAA in comparison to no therapy was $13,800/QALY, below the willingness-to-pay threshold of $50,000/QALY. CONCLUSION: Hepatitis C treatment with DAA prior to THA is cost-effective at all current drug list prices. Given these findings, strong consideration should be given to treating patients for HCV prior to elective THA. LEVEL OF EVIDENCE: Cost-effectiveness Analysis; Level III.

Perioperative management of leg-length discrepancy in total hip arthroplasty: a review.

Leg-length discrepancy (LLD) presents a significant management challenge to orthopedic surgeons and remains a leading cause of patient dissatisfaction and litigation after total hip arthroplasty (THA). Over or under-lengthening of the operative extremity has been shown to have inferior outcomes, such as dislocation, exacerbation of back pain and sciatica, and general dissatisfaction postoperatively. The management of LLD in the setting of THA is multifactorial, and must be taken into consideration in the pre-operative, intra-operative, and post-operative settings. In our review, we aim to summarize the best available practices and techniques for minimizing LLD through each of these phases of care. Pre-operatively, we provide an overview of the appropriate radiographic studies to be obtained and their interpretation, as well as considerations to be made when templating. Intra-operatively, we discuss several techniques for the assessment of limb length in real time, and post-operatively, we discuss both operative and non-operative management of LLD. By providing a summary of the best available practices and strategies for mitigating the impact of a perceived LLD in the setting of THA, we hope to maximize the potential for an excellent surgical and clinical outcome.

Is Metformin Use Associated with Prolonged Overall Survival in Patients with Soft Tissue Sarcoma? A SEER-Medicare Study.

BACKGROUND: Metformin, an oral drug used to treat patients with diabetes, has been associated with prolonged survival in patients with various visceral carcinomas. Although the exact mechanisms are unknown, preclinical translational studies demonstrate that metformin may impair tumor cellular metabolism, alter matrix turnover, and suppress oncogenic signaling pathways. Currently used chemotherapeutic agents have not been very successful in the adjuvant setting or for treating patients with metastatic sarcomas. We wanted to know whether metformin might be associated with improved survival in patients with a soft tissue sarcoma. QUESTIONS/PURPOSES: In patients treated for a soft tissue sarcoma, we asked: (1) Is there an association between metformin use and longer survival? (2) How does this association differ, if at all, among patients with and without the diagnosis of diabetes? METHODS: The Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database was used to identify patients with a diagnosis of soft tissue sarcoma from 2007 to 2016. Concomitant medication use was identified using National Drug Codes using the Medicare Part D event files. This database was chosen because of the large number of captured sarcoma patients, availability of tumor characteristics, and longitudinal linkage of Medicare data. A total of 14,650 patients were screened for inclusion. Patients with multiple malignancies, diagnosis at autopsy, or discrepant linkage to the Medicare database were excluded. Overall, 4606 patients were eligible for the study: 598 patients taking metformin and 4008 patients not taking metformin. A hazard of mortality (hazard ratio) was analyzed comparing patients taking metformin with those patient groups not taking metformin and expressed in terms of a 95% confidence interval. Cox regression analysis was used to control for patient-specific, disease-specific, and treatment-specific covariates. RESULTS: Having adjusted for disease-, treatment-, and patient-specific characteristics, patients taking metformin experienced prolonged survival compared with all patients not taking metformin (HR 0.76 [95% CI 0.66 to 0.87]). Associated prolonged survival was also seen when patients taking metformin were compared with those patients not on metformin irrespective of a diabetes diagnosis (HR 0.79 [95% CI 0.66 to 0.94] compared with patients with a diagnosis of diabetes and HR 0.77 [95% CI 0.67 to 0.89] compared with patients who did not have a diagnosis of diabetes). CONCLUSION: Without suggesting causation, we found that even after controlling for confounding variables such as Charlson comorbidity index, tumor grade, size, stage, and surgical/radiation treatment modalities, there was an association between metformin use and increased survival in patients with soft tissue sarcoma. When considered separately, this association persisted in patients not on metformin with and without a diabetes diagnosis. Although metformin is not normally prescribed to patients who do not have a diabetes diagnosis, these data support further study, and if these findings are substantiated, it might lead to the performance of multicenter, prospective clinical trials about the use of metformin as an adjuvant therapy for the treatment of soft tissue sarcoma in patients with and without a preexisting diabetes diagnosis. LEVEL OF EVIDENCE: Level III, therapeutic study.

Narrative review of the epidemiology, economic burden, and societal impact of metastatic bone disease.

As the prevalence of cancer continues to rise in the United States due to a combination of both early detection and increased life expectancy, the number of clinically symptomatic skeletal metastases will continue to grow. Healthcare expenditures on cancer treatment have steadily increased each decade to our estimated level of approximately $200 billion in 2020. Metastatic bone disease is a significant driver of this cost, accounting for nearly one-fifth of the total cost of oncologic treatment. Understanding the impact of metastatic bone disease can help to identify the gaps between diagnosis and initiation of treatment in an effort to decrease the socioeconomic and psychosocial implications of the disease. In this paper, we review the epidemiology and economic burden of metastatic bone disease in addition to other sequelae that affect patients, including financial hardship, caregiver burden, diminished quality of life and psychological impact. Upon literature review of multiple studies investigating these factors, we found that advanced metastatic bone disease had overall poor outcomes with regards to the socioeconomic and psychosocial effects on not only patients and their families, but also society at large. These consequences may be improved by early referral to orthopedic specialists and establishment of a multi-disciplinary team.

Perioperative Management of Hepatitis C in Patients Undergoing Total Joint Arthroplasty.

¼: A small yet growing subset of total joint arthroplasty (TJA) candidates are diagnosed with the hepatitis C virus (HCV), which is a known risk factor for periprosthetic joint infections. Given the poor outcomes associated with TJA infection, we recommend that candidates with HCV receive treatment prior to elective TJA. ¼: Interferon and ribavirin have historically been the standard treatment regimen for the management of HCV; however, adverse events and an inconsistent viral response have limited the efficacy of these therapies. The advent of direct-acting antivirals has resolved many of the issues associated with interferon and ribavirin regimens. ¼: Despite the success of direct-acting antivirals, there are still barriers to seeking treatment for TJA candidates with HCV. Many patients are faced with financial burdens, as insurance coverage of direct-acting antiviral therapies is inconsistent and varies by the patient's state of residence and specific treatment regimen. ¼: TJA candidates with HCV present health-care providers with a unique set of challenges, often encompassing economic, psychosocial, and complex medical concerns. Multidisciplinary care teams can be beneficial when caring for and optimizing this patient cohort. ¼: Management of HCV prior to elective TJA is associated with higher up-front costs but ultimately reduces long-term patient morbidity as well as associated direct and indirect health-care expenditures.

Oral health implications in total hip and knee arthroplasty patients: A review.

Over the past two decades, oral health has emerged as a health care priority. Historically, patients greater than 65 years of age, the economically disadvantaged, members of racial or ethnic minority groups, or the disabled or home bound have experienced significant barriers to routine dental care. The connection between oral health care and periprosthetic joint infections (PJI) continues to be of importance to the orthopedic surgeon, as such infections are significantly morbid and costly. This review aims to introduce the importance of oral health as a small but crucial portion of an arthroplasty patient's overall perioperative management.

The Use of Dual Mobility Implants in Patients Who Are at High Risk for Dislocation After Primary Total Hip Arthroplasty.

Dislocation after total hip arthroplasty (THA) is the leading cause of revision surgery. Dual mobility (DM) implants have been utilized over the past 40 years as a means of addressing and preventing this morbid and expensive complication. Recently, there has been renewed investigation into the role that DM implants may play in reducing instability in high-risk patients. Hemiarthroplasty or traditional THA remain the mainstays of treatment for older patients with displaced femoral neck fractures. Longer-term higher-quality studies are necessary to investigate whether DM THA outcomes may be superior to traditional THA in the physiologically young patient with high physical demands and a longer-than-average life expectancy. The use of DM implants in preventing dislocation in patients with fixed spinopelvic alignment, neuromuscular disorders, and failed fixation of previously sustained proximal femoral fractures has shown success in studies with low levels of evidence. More robust prospective data are necessary before more widespread adoption of DM arthroplasty is recommended in these clinical scenarios. Knowledge of the pertinent literature with regard to the use of DM implants in patients who are at high risk for instability will allow orthopaedic surgeons to make informed decisions as to whether or not their patients may benefit from primary THA utilizing DM implants.

Is Blastomycosis Endemic in Upstate New York?: A Case Report and Review of Literature.

CASE: We describe a case of biopsy-proven blastomycosis in a patient residing in Upstate New York with osseous and skin lesions and no pulmonary or constitutional symptoms. The patient had a rapid resolution of symptoms after the initiation of antifungal treatment, followed by curettage and cementation of her distal femoral lesion. CONCLUSIONS: Orthopaedic surgeons should be aware of the presence of blastomycosis in nonendemic areas, especially since bone involvement may be the predominant manifestation. Tissue should be submitted for both histologic and microbiologic analysis. Antifungal therapy and surgical management if needed can result in a good outcome.

The Quality of Online Orthopaedic Oncology Information.

"Cancer" is one of the top three health-related Internet searches, yet research shows over 30% of patients are confused after searching for medical information. The quality and accuracy of Internet oncology literature varies widely and can affect patient perceptions or seeking of care. Purpose: This study hypothesizes that online patient resources for orthopaedic oncology are often inconsistent, inaccurate, or incomprehensible by the standard patient and examines the readability, quality, and accuracy of common orthopaedic oncology websites. Methods: Three common search terms were searched in three popular search engines. The first 25 nonsponsored websites were identified for each term; randomized to search term; and evaluated via a 25-question quality score, DISCERN treatment-based score, predetermined accuracy score, and Flesch-Kincaid reading level. Results: Forty-eight websites were included. Website quality, DISCERN score, accuracy score, and reading level were not statistically different based on search term. Quality and DISCERN scores were markedly higher from websites without commercial gain. Websites were consistently written above the recommended reading level. Discussion: Online orthopaedic oncology literature is frequently confusing and complicated. The orthopaedic surgeon should be aware that patients frequently access this information and should ensure that patients receive accurate primary source material relevant to their care.

Economic Recovery After the COVID-19 Pandemic: Resuming Elective Orthopedic Surgery and Total Joint Arthroplasty.

BACKGROUND: The economic effects of the COVID-19 crisis are not like anything the U.S. health care system has ever experienced. METHODS: As we begin to emerge from the peak of the COVID-19 pandemic, we need to plan the sustainable resumption of elective procedures. We must first ensure the safety of our patients and surgical staff. It must be a priority to monitor the availability of supplies for the continued care of patients suffering from COVID-19. As we resume elective orthopedic surgery and total joint arthroplasty, we must begin to reduce expenses by renegotiating vendor contracts, use ambulatory surgery centers and hospital outpatient departments in a safe and effective manner, adhere to strict evidence-based and COVID-19-adjusted practices, and incorporate telemedicine and other technology platforms when feasible for health care systems and orthopedic groups to survive economically. RESULTS: The return to normalcy will be slow and may be different than what we are accustomed to, but we must work together to plan a transition to a more sustainable health care reality which accommodates a COVID-19 world. CONCLUSION: Our goal should be using these lessons to achieve a healthy and successful 2021 fiscal year.

Orthopaedic Manifestations of Melanoma and Their Management.

Melanoma is an aggressive form of skin cancer associated with significant morbidity and mortality. Although commonly seen in dermatologist clinics, orthopaedic surgeons must be aware of these lesions in various ways. The five common musculoskeletal manifestations of melanoma will be discussed as well as the epidemiology, pathogenesis, diagnosis, staging, treatment, and prognosis of melanoma. With an index of suspicion and awareness of melanoma, a thorough history and detailed physical examination are critical in establishing a diagnosis. An adequately performed biopsy will confirm the diagnosis and assist in determining prognosis. As ambassadors of health for the musculoskeletal system, orthopaedic surgeons may be the first practitioners to encounter a pigmented skin lesion. Acral pigmented lesions should prompt a concern for melanoma with appropriate subsequent steps for management to follow. Finally, it is important for every orthopaedic surgeon to consider disseminated melanoma in the differential diagnosis of a skeletal metastasis, a deep soft-tissue mass, or lymphadenopathy in a patient with a previous history of a melanotic lesion.

Team Approach: Evaluation and Management of Low-Grade Cartilaginous Lesions.

¼ Assessment of chondral lesions begins with a clinical evaluation and radiographs. ¼ Longitudinal follow-up with serial radiographs is appropriate in cases without evidence of aggressive radiographic features. ¼ Concerning radiographic features include periosteal reaction, soft-tissue extension, cortical destruction, endosteal scalloping of greater than two-thirds of the native cortex, larger lesion size (≥5 cm), and location in the axial skeleton. ¼ Biomarkers such as IMP3, SOX4, microRNA, and periostin may be used as an adjunct in histologic assessment to help differentiate benign enchondroma from a low-grade chondrosarcoma. ¼ Advanced-imaging studies, such as computed tomography (CT), bone scans, magnetic resonance imaging (MRI), dynamic contrast-enhanced MRI, and fluorodeoxyglucose positron emission tomography (FDG-PET), may be considered for borderline cases. ¼ Aggressive or concerning radiographic features should prompt evaluation with advanced imaging or referral to an orthopaedic oncologist.

What is the Proportion of Patients With Multiple Hereditary Exostoses Who Undergo Malignant Degeneration?

BACKGROUND: Multiple hereditary exostoses is an autosomal-dominant skeletal disorder that has a wide-ranging reported risk of malignant degeneration to chondrosarcoma. QUESTIONS/PURPOSES: The aims of our study were to use a large, web-based survey approach to characterize (1) the demographic distribution of patients with multiple hereditary exostoses, (2) the number of surgeries performed related to one's diagnosis of multiple hereditary exostoses, and (3) the proportion of survey respondents who described experiencing malignant degeneration in a large international, heterogeneous cohort of patients with multiple hereditary exostoses. METHODS: An anonymous web-based survey was distributed to several online support groups and social media networks designed to support and educate patients with multiple hereditary exostoses and their families. The survey collected demographic and epidemiologic data on 779 respondents. Data were recorded to assess respondents' disease burden and the rate of malignant degeneration. RESULTS: Females represented a slightly greater proportion of those with multiple hereditary exostoses who responded (56% female; 419 of 742 patients). Median age for all respondents was 28 years (range, < 1-85 years). Median age for males was 25 years (range, < 1-85 years), while median age for females was 29 years (range, < 1-82 years). The mean age at diagnosis of male and female respondents was in the mid-first decade (5.4 years ± 7.2 years). The mean number of surgeries a patient had undergone was 7.3 (± 7.1 surgeries). The proportion of respondents who experienced malignant transformation was 2.7% (21 of 757 respondents), at a mean age of 28.6 years (± 9.3 years). The most common sites of malignant change from benign exostoses included the pelvis (eight of 21 respondents) and scapula (four of 21 respondents). CONCLUSIONS: In the largest and most geographically diverse study of patients with multiple hereditary exostoses of which we are aware, we found the proportion of patients with multiple hereditary exostoses who have undergone malignant degeneration to be consistent with those reported in prior studies. Our study perhaps more accurately assessed the proportion of patients who undergo malignant transformation of multiple hereditary exostoses. As with prior studies on this topic, the proportion of malignant change may be expected to represent a high-end estimate as recruitment and selection bias likely predisposes for patients with more severe disease, whereas patients with lesser disease may be unaware of their diagnosis. In discussing the sequelae of multiple hereditary exostoses, clinicians perhaps might use this study to offer an unspecific statement of risk of malignant degeneration of multiple hereditary exostoses among the population at large. LEVEL OF EVIDENCE: Level IV, prognostic study.

Diagnosis and management of langerhans cell histiocytosis.

Langerhans cell histiocytosis is a rare group of disorders without a well-understood etiology. Known formerly as histiocytosis X, the disease has a wide spectrum of clinical presentations, including eosinophilic granuloma (solitary bone lesion), diabetes insipidus, and exophthalmos. It is also known by several eponyms, including Hand-Schüller-Christian disease when it manifests as a triad of cranial bone lesions and Letterer-Siwe disease when it is found in infantile patients with severely disseminated disease. Children aged 5 to 15 years are most commonly affected. Many of these patients initially present to orthopaedic surgeons, and misdiagnosis is frequent. To accurately diagnosis and treat these patients, the orthopaedic surgeon must be familiar with the clinical manifestations and pathophysiology of the disease as well as the treatment guidelines and outcomes for Langerhans cell histiocytosis.