Imaging Features and Management of Stress, Atypical, and Pathologic Fractures.

Traumatic and atraumatic fractures are entities with distinct but often overlapping clinical manifestations, imaging findings, and management protocols. This article is a review of terminology, etiology, and key imaging features that affect management of atraumatic fractures including stress fractures, atypical femoral fractures, and pathologic fractures. The terminology of atraumatic fractures is reviewed, with an emphasis on the distinctions and similarities of stress, atypical, and pathologic fractures. The basic biomechanics of normal bone is described, with an emphasis on the bone remodeling pathway. This framework is used to better convey the shared etiologies, key differences, and important imaging findings of these types of fractures. Next, the characteristic imaging findings of this diverse family of fractures is discussed. For each type of fracture, the most clinically relevant imaging features that guide management by the multidisciplinary treatment team, including orthopedic surgeons, are reviewed. In addition, imaging features are reviewed to help discriminate stress fractures from pathologic fractures in patients with challenging cases. Finally, imaging criteria to risk stratify an impending pathologic fracture at the site of an osseous neoplasm are discussed. Special attention is paid to fractures occurring in the proximal femur because the osseous macrostructure and mix of trabecular and cortical bone of the proximal femur can function as a convenient framework to understanding atraumatic fractures throughout the skeleton. Atraumatic fractures elsewhere in the body also are used to illustrate key imaging features and treatment concepts. ©RSNA, 2018.

Arthroscopy After Traumatic Hip Dislocation: A Systematic Review of Intra-articular Findings, Correlation With Magnetic Resonance Imaging and Computed Tomography, Treatments, and Outcomes.

PURPOSE: To describe the literature concerning patient demographic characteristics and intra-articular injury seen at arthroscopy after traumatic hip dislocation, describe the reported computed tomography (CT) and magnetic resonance findings with arthroscopic correlation, and describe the reported arthroscopic treatments performed with complications and outcomes. METHODS: A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for assessment of arthroscopy after hip dislocation. Three databases were searched, and study screening and data abstraction were performed in duplicate. RESULTS: Thirty-one heterogeneous case series and case reports were included in the analysis from the initial search yielding 780 results, including reports of 151 patients who underwent arthroscopy after traumatic hip dislocation. A wide spectrum of intra-articular injury was reported, with a high prevalence of labral tears, intra-articular bodies, ligamentum teres injuries, and chondral damage. CT had a sensitivity of 87.3% for detecting intra-articular fragments; however, 43.3% of patients who had a preoperative CT scan with negative findings for intra-articular fragments did show fragments at arthroscopy. Magnetic resonance had a sensitivity of 95.0% for detecting labral tears. There were no major complications directly attributed to arthroscopic surgery. A total of 75 of 151 patients were followed up for a median of 2 years after surgery, with osteoarthritis reported in 4.0% and avascular necrosis in 2.7%. CONCLUSIONS: In patients with traumatic hip dislocation, heterogeneously reported previously published cases show that arthroscopy reveals a broad spectrum of intra-articular damage amenable to arthroscopic intervention. CT is not sensitive in the detection of intra-articular bodies in all cases. Although no serious periprocedural adverse events were reported, only 49.7% of patients had reported follow-up data, and further prospective studies would be necessary to show the safety and efficacy of arthroscopy in comparison with conventional treatment algorithms of hip dislocation. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

Traumatic Hip Dislocation: What the Orthopedic Surgeon Wants to Know.

Hip dislocation is an important orthopedic emergency usually seen in young patients who have experienced high-energy trauma, often resulting in significant long-term morbidity. Rapid identification and reduction is critical, as prolonged dislocation increases the risk of developing avascular necrosis of the femoral head, and posttraumatic osteoarthritis is a common complication, even in the absence of associated fractures. Identification and timely management of hip dislocation are highly dependent on imaging, both at presentation and after attempted reduction. It is imperative for the radiologist to understand imaging features that guide management of hip dislocation to ensure timely identification, characterization, and communication of clinically relevant results. Although the importance of prompt identification of hip dislocation is universally recognized, the significance of imaging features that guide correct management and are thought to prevent complications is less emphasized in the radiology literature. In this article, the authors review the anatomy of the hip, common injury mechanisms for various types of dislocations, and imaging findings for associated injuries. They review the most commonly used classification systems and propose a simplified checklist approach to hip dislocation to aid rapid interpretation and communication of the most clinically relevant imaging features to the treating orthopedic surgeon. ©RSNA, 2017.

Periprosthetic Femoral Fractures in the Emergency Department: What the Orthopedic Surgeon Wants to Know.

Femoral fracture in the setting of a hip arthroplasty is an increasingly common complication encountered in the emergency department (ED). Diagnosis and management of periprosthetic fractures are complicated, and orthopedic surgeons rely on imaging findings to guide the appropriate management approach to the injury. Delay in identification and appropriate definitive management of periprosthetic fractures is associated with high morbidity and mortality. At present, the Vancouver classification system for periprosthetic hip fractures is the most common classification system used by orthopedic surgeons. It relies on three radiographic criteria-fracture location, prosthesis stability, and quality of the femoral bone stock-to characterize these fractures and to help guide management decisions. Familiarly with the Vancouver classification system allows radiologists to both recognize and communicate the most clinically relevant imaging findings to the treating orthopedic surgeon. This article reviews the imaging workup for hip pain in patients with a femoral prosthesis, risk factors for periprosthetic fracture, and the expected normal appearance of the most commonly encountered types of femoral prostheses. Fracture terminology and the Vancouver classification system are reviewed in a simplified algorithm with emphasis on the most common patterns of periprosthetic fractures, the radiologic determinants of prosthesis stability and bone quality, and the management implications of these imaging findings. Finally, multiple instructive clinical cases are used to demonstrate critical application of the classification system and to highlight the clinical implications of the imaging findings. ©RSNA, 2017.

Treatment outcomes and morbidity following definitive brachytherapy with or without external beam radiation for the treatment of localized prostate cancer: 20-year experience at Mount Sinai Medical Center.

OBJECTIVES: To present our treatment algorithm and 20-year experience in treating prostate cancer with brachytherapy since 1990, with focus on cancer-control outcomes and treatment-related morbidity. METHODS AND MATERIALS: We selected patients treated for localized prostate cancer with brachytherapy, combination therapy with external beam radiotherapy, and adjuvant androgen deprivation therapy as prescribed by our Mount Sinai risk stratification and treatment algorithm. Outcomes were analyzed with respect to biochemical failure, distant metastases, prostate cancer-specific survival, and overall survival. Morbidity was assessed with respect to urinary, sexual, and rectal outcomes. RESULTS: In total, 2,495 patients met inclusion criteria. The 12-year actuarial freedom from biochemical failure was 83% (low risk: 90%, intermediate risk: 84%, and high risk: 64%); freedom from distant metastasis was 95%; prostate cancer-specific survival was 95%; and overall survival was 70%. On multivariate analysis, significant associations were found between cancer control and risk group, total biologically effective dose, and androgen deprivation therapy. With regard to morbidity, potency was preserved in 61%, and urinary symptoms improved in 35%. The 12-year actuarial freedom from urinary retention events was 90% and from severe rectal bleed was 93%. CONCLUSIONS: Brachytherapy, as administered via the Mount Sinai algorithm, remains an efficacious and benign treatment option for patients with localized prostate cancer of all risk groups.