Spindle cell neoplasm with EML4-ALK gene fusion presenting as an intraosseous vertebral mass.

In this article, we describe a spindle cell neoplasm harboring an EML4-ALK gene fusion presenting as an intraosseous vertebral mass with extension into the adjacent soft tissue in a 65-year-old man. Histologically, the lesion was characterized by the presence of monotonous, cytologically bland spindle cells with loose myxoedematous stroma and interspersed areas of amianthoid-like collagen fiber deposition. Immunohistochemistry demonstrated strong diffuse staining for CD34 and S100, with absent immunoreactivity for SOX10. At 1 year of follow-up after resection, there is no evidence of local recurrence or metastatic disease. This case adds to the clinical and pathologic spectrum of the recently described group of kinase fusion-positive spindle cell neoplasms and represents the first reported intra-osseous example. The presence of ALK rearrangement in this lesion represents a potential therapeutic target, if clinically indicated.

Weightbearing Digital Tomosynthesis of Foot and Ankle Arthritis: Comparison With Radiography and Simulated Weightbearing CT in a Prospective Study.

OBJECTIVE: Foot and ankle arthritis is common and debilitating. Weightbearing radiography is the reference standard for evaluating alignment, but overlapping bones and hardware limit evaluation for osteoarthritic bony detail. The purpose of this study was to evaluate whether digital tomosynthesis (DTS) can yield reliable quantitative alignment values, as radiography does with its weightbearing capability, and good qualitative osteoarthritic detail, as CT does. SUBJECTS AND METHODS: Adults with foot or ankle arthritis referred for simulated weightbearing CT were recruited to undergo weightbearing radiography and DTS. Four readers independently evaluated radiographs and DTS images for foot and ankle alignment and severity of osteoarthritis in each joint. Two readers performed consensus readings of CT images. Agreement between modalities was assessed by intraclass correlation coefficient (ICC) and Cohen kappa statistics. RESULTS: Ninety-one ankles were analyzed. Most joints were significantly less obscured by overlapping bone when seen with DTS (11.2%) or CT (4.3%) compared with radiography (30.4%). For quantitative foot alignment measurements, DTS had good to excellent agreement with weightbearing radiography (ICC, 0.65-0.93), which performed significantly better than CT (ICC, 0.39-0.87). For qualitative osteoarthritic details of each joint, DTS had significantly better agreement with weightbearing radiography on joint space narrowing (κ = 0.38-0.67) than did CT (κ = 0.08-0.62). Weightbearing radiography and DTS had similar levels of agreement with CT on grading of osteophytes, subchondral cysts, and loose bodies. CONCLUSION: DTS is associated with less obscuration of joints than radiography and yields more reliable weightbearing quantitative foot and ankle alignment values than radiography does and more reliable osteoarthritic bony details than CT does.

Surgical Correction of Articular Damage in the Knee: Osteoarticular Transplantation to Joint Reconstruction.

Injuries of the articular cartilage remain difficult to treat and can range from small articular cartilage defects to end-stage severe osteoarthritis. In this review, we discuss various surgical treatment options including imaging features and associated complications. Specifically, we review microfracture, acellular matrix-induced microfracture, autologous osteochondral transplantation, osteochondral allograft transplantation, autologous chondrocyte implantation, along with various forms of knee arthroplasties.

Cuff tear arthropathy shoulder hemiarthroplasty: a radiographic outcome study.

OBJECTIVE: Cuff tear arthropathy (CTA) head prosthesis has recently become an alternative to standard shoulder hemiarthroplasty in patients with severe cuff disease by offering an increased surface area and decreased impingement. The purpose of this study is to evaluate the radiographic outcomes of CTA prosthesis and to correlate them with clinical outcomes. MATERIALS AND METHODS: In this retrospective study of CTA hemiarthroplasties over an 11-year period, two radiologists reviewed pre-/postoperative radiographs and clinical data. Radiographic complications were correlated with subsequent surgery using Cox regression models. Rates of surgical revision and radiographic complications over time were estimated using Kaplan-Meier curves. RESULTS: Ninety-seven CTA hemiarthroplasties were identified in 92 patients (5 bilateral) with a mean patient age of 68.7 years. Mean radiographic follow-up was 12 months with a mean of 3.3 radiographs per prosthesis. Twenty-six arthroplasties (26.8%) experienced at least one radiographic complication, including acromion remodeling (19.5%), anterior-posterior subluxation (5.2%), periprosthetic fracture (4.1%), glenoid remodeling (3.1%), hardware loosening (2.1%), superior subluxation (2.1%), and subsidence (1.0%). Eight cases underwent revision surgery (8.2%). The occurrence of a postoperative radiographic complication was associated with increased risk of surgical revision (hazard ratio 11.5, 95% CI: 2.4-55.7, p = 0.002); 73.5% of radiographic complications occurred by 3 months after the initial surgery (complication rate of 23.3%) based on Kaplan-Meier curve analysis. CONCLUSION: Radiographic complications after CTA head hemiarthroplasty are common with most occurring by 3 months after surgery and are highly associated with surgical revision.

Long-term radiographic follow-up of bisphosphonate-associated atypical femur fractures.

OBJECTIVE: To evaluate the appearance of bisphosphonate-related femur insufficiency fractures on long-term follow-up radiographic studies and to describe the rate of fracture line obscuration and cortical beak healing over time. MATERIALS AND METHODS: In this retrospective study, bisphosphonate-related femur fracture radiographs were reviewed by two radiologists for the presence of a fracture line, callus, and the characteristic cortical beak. Kaplan-Meier curves were used to analyze the time to first indication of healing. Femurs were also subdivided into those who underwent early versus late surgical fixation and those who underwent early versus late discontinuation of bisphosphonate. Clinical data including pain level and medication history were collected. RESULTS: Forty-seven femurs with a bisphosphonate-related femur fracture were identified in 28 women. Eighty-five percent took a bisphosphonate for greater than 5 years and 59 % for greater than 10 years. The median time to beak healing was 265 weeks and the median time to fracture line healing was 56 weeks in the 31 femurs with a baseline fracture. No statistically significant difference was identified between surgical fixation and conservative management. CONCLUSIONS: Bisphosphonate-related fractures demonstrate notably prolonged healing time on long-term follow-up.

Total elbow arthroplasty: a radiographic outcome study.

OBJECTIVES: Total elbow arthroplasty (TEA) is becoming a popular alternative to arthrodesis for patients with end-stage elbow arthrosis and comminuted distal humeral fractures. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TEA and to correlate with clinical symptoms such as pain. MATERIALS AND METHODS: This is an IRB-approved retrospective review from 2005 to 2015 of all patients with semiconstrained TEA. All available elbow radiographs and clinical data were reviewed. Data analysis included descriptive statistics and Kaplan-Meier survival curves for radiographic and clinical survival. RESULTS: A total of 104 total elbow arthroplasties in 102 patients were reviewed; 75 % were in women and the mean patient age was 63.1 years. Mean radiographic follow-up was 826 days with average of four radiographs per patient. Seventy TEAs (67 %) developed radiographic complications, including heterotopic ossification (48 %), perihardware lucency (27 %), periprosthetic fracture (23 %), hardware subluxation/dislocation (7 %), polyethylene wear (3 %), and hardware fracture/dislodgement (3 %); 56 patients (55 %) developed symptoms of elbow pain or instability and 30 patients (30 %) underwent at least one reoperation. In patients with radiographic complications, 66 % developed elbow pain, compared to 19 % of patients with no radiologic complications (p = 0.001). Of the patients with radiographic complications, 39 % had at least one additional surgery compared to 0 % of patients without radiographic complications (p = 0.056). CONCLUSIONS: Radiographic complications are common in patients after total elbow arthroplasty. There is a strong positive association between post-operative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist.

Digital Tomosynthesis to Evaluate Fracture Healing: Prospective Comparison With Radiography and CT.

OBJECTIVE: Radiography, currently the standard for postoperative fracture imaging, is limited by overlapping bone and hardware. Tomosynthesis has the benefit of level-by-level imaging without the disadvantages of metal artifacts, increased radiation, and higher costs of CT, the current problem-solving tool. The purpose of this study was to compare tomosynthesis with radiography for evaluating fracture healing. SUBJECTS AND METHODS: In a prospective study, patients within 1 year of wrist hardware fixation underwent radiography, tomosynthesis, and CT, and the images were interpreted by three readers. The diagnostic accuracy of radiology and tomosynthesis was assessed with ROC curves, and interreader agreement was assessed with Cohen kappa. Fracture scores were correlated with Disabilities of the Arm, Shoulder, and Hand (DASH) and pain scores. RESULTS: The study participants were 49 patients with 51 fractures. The most common fracture sites were distal radius (43%), scaphoid (18%), and metacarpals (18%). Rates of cortex obscuration by hardware were 2% for CT, 8% for tomosynthesis, and 15% for radiography (p < 0.01 between one modality and another). Detection of cortical fracture lines was significantly better with tomosynthesis than with radiography (AUC, 0.84 vs 0.76, p = 0.01). Inter-reader agreement was moderate for both radiography and tomosynthesis (κ = 0.44 vs 0.55, p = 0.051). There was no significant correlation between fracture scores and DASH scores. There was significant correlation between reported pain levels and both tomosynthesis (r = 0.28, p = 0.03) and CT (r = 0.29, p = 0.04) fracture scores. CONCLUSION: Tomosynthesis provides diagnostic information superior to that of ra diography in postoperative evaluation of wrist fractures with lower cost and radiation than CT and should be considered in fracture follow-up imaging of other bones.

Osteoarticular transplantation: recognizing expected postsurgical appearances and complications.

Despite technologic advances in prosthetic joint replacement, young patients who have lost a large volume of bone or soft tissue because of a tumor or traumatic injury may not be good candidates for prosthetic implants, which have limited longevity relative to that of biologic tissue grafts. In recent years, the use of biologic materials in orthopedic surgery has increased. Such materials, known as allografts, consist of cadaveric bone, cartilage, and other soft tissues that can be transplanted into a living patient. Alternatively, osteochondral autografts, or autologous grafts of the patient's own bone and/or cartilage, can be harvested from one body site and transplanted to another. Surgical procedures range from the local implantation of small osteochondral plugs to the replacement of entire joints with allografts. The size of the allograft used depends on the amount of bone and soft tissue needed. The use of allografts in patients with large-volume bone loss often preserves limb function, obviating amputation, which makes it an attractive option for treatment of young patients. Advantages of using allografts include the similarity of graft materials to native tissues and the decreased patient morbidity in the absence of an autograft donor site; disadvantages include slower biologic remodeling and graft incorporation than are typical with the use of autologous grafts. Potential complications of allograft tissue implantation include graft nonunion, collapse, and failure; infection; and secondary osteoarthritis. The article discusses the indications for and basic steps involved in each type of transplant procedure, normal pre- and postoperative imaging appearances, and imaging features that may be indicative of transplant complications.

Imaging of adverse reactions to metal debris.

Hip replacements with metal-on-metal components can cause a spectrum of adverse tissue reactions-from benign localized fibrosis and chronic inflammation to delayed hypersensitivity response. In addition to history, physical examination, and relevant laboratory data, imaging plays a critical role in the evaluation of hip arthroplasties. Imaging assessment begins with radiographs and may be followed by ultrasound, computed tomography, or MRI. MRI optimized for metal artifact reduction is the most sensitive and specific imaging modality and is essential in assessing the spectrum of metal-related adverse tissue reactions. In this article, we discuss the history, pathophysiology, and imaging findings of adverse reactions to metal debris.

Imaging current spine hardware: part 1, cervical spine and fracture fixation.

OBJECTIVE: The goals of this article are to review the indications for use, the materials, and the designs of hardware more commonly used in the cervical spine; to discuss alternatives for each of the different types of hardware; to review normal postoperative imaging findings; to describe the appropriateness of different imaging modalities for postoperative evaluation; and to illustrate examples of hardware complications. This article will also review vertebral body fracture fixation. CONCLUSION: Stabilization and fusion of the spine with intervertebral disk replacement, artificial ligaments, spinous process distraction devices, plate-and-rod systems, dynamic posterior fusion devices, and implants composed of new types of material are increasingly more common in the contemporary surgical practice. These spinal hardware devices will be seen more often in radiology practice. Successful postoperative radiologic evaluation of spinal hardware necessitates an understanding of the fundamental design of the hardware, the physiologic objective of the hardware, normal and abnormal postoperative imaging appearances, and complications unique to the hardware.

Radiographic pitfalls in lower extremity trauma.

OBJECTIVE: Radiography remains the imaging standard for fracture detection after trauma. However, fractures continue to be the most common type of missed injuries. In this article, we describe common radiographic pitfalls in lower extremity trauma and describe strategies for dealing with them. CONCLUSION: Pitfalls include insufficient views, improperly positioned or technically imperfect radiographs, nondisplaced fractures, commonly missed locations, small avulsions portending large injury, sesamoid injuries, satisfaction of search, incomplete or faulty reasoning, and periprosthetic fractures.

Imaging of current spinal hardware: lumbar spine.

OBJECTIVE: The purposes of this article are to review the indications for and the materials and designs of hardware more commonly used in the lumbar spine; to discuss alternatives for each of the types of hardware; to review normal postoperative imaging findings; to describe the appropriateness of different imaging modalities for postoperative evaluation; and to show examples of hardware complications. CONCLUSION: Stabilization and fusion of the lumbar spine with intervertebral disk replacement, artificial ligaments, spinous process distraction devices, plate-and-rod systems, dynamic posterior fusion devices, and newer types of material incorporation are increasingly more common in contemporary surgical practice. These spinal hardware devices will be seen more often in radiology practice. Successful postoperative radiologic evaluation of this spinal hardware necessitates an understanding of fundamental hardware design, physiologic objectives, normal postoperative imaging appearances, and unique complications. Radiologists may have little training and experience with the new and modified types of hardware used in the lumbar spine.

Acromioclavicular joint: the other joint in the shoulder.

OBJECTIVE: The purpose of this article is to provide a review of acromioclavicular joint anatomy, describe common pathologies at the joint, and present normal and abnormal postoperative imaging findings after surgical treatments. CONCLUSION: Knowledge of anatomy with related pathologies, orthopedic trends, imaging findings, and complications, is important in assessing the acromioclavicular joint.

Fractures of the distal radius: postmanagement radiographic characterization.

OBJECTIVE: The purpose of this article is to describe the management options available for the treatment of the distal radius fracture as well as potential associated complications. CONCLUSION: There are a wide variety of currently accepted and used treatment options for fractures of the distal radius, ranging from closed reduction with casting to various forms of invasive surgical management. The radiologist must be familiar with these various forms of management to recognize complications when present on follow-up radiographs.

Fracture of the distal radius: epidemiology and premanagement radiographic characterization.

OBJECTIVE: Fractures of the distal radius are common and frequently encountered by the radiologist. We review the epidemiology, classification, as well as the concept of instability. Salient qualitative and quantitative features of the distal radius fracture identifiable on the routine radiography series are highlighted. We conclude with a synopsis of descriptors that are of greatest utility to the clinician for treatment planning and that should be addressed in the radiology report. CONCLUSION: A detailed understanding of the intricacies of the distal radius fracture is necessary for the radiologist to provide a clinically relevant description.

Update on talar fracture patterns: a large level I trauma center study.

OBJECTIVE: Prior studies of talar fracture patterns are dated and based on radiography only. The purpose of our study was to describe talar fracture patterns and associated injuries in a modern large level 1 trauma center setting using both radiography and CT. MATERIALS AND METHODS: The radiolog and clinical data of patients with acute talar fractures diagnosed over an 18-month period were retrospectively reviewed. Data analysis included descriptive statistics for injury mechanisms and associated injuries. RESULTS: Over the study period, a total of 132 talar fractures were detected in 122 patients. The most common talar fracture location was the body (61%). The most common body fractures were dome compression (26%), lateral process (24%), and posterior tubercle (21%). Of the 132 fractures, 62% were comminuted and 21 (16%) were vertical neck fractures compatible with the Hawkins-Canale classification. Both radiography and CT were used in 91% of cases, with CT providing additional information in 112 (93%) cases. By use of CT as the reference standard, the sensitivity of radiography for detecting talar fractures was 74%. The most common fracture missed by radiography was talar dome compression (31% not seen on radiography) Talar fractures were associated with adjacent joint subluxation or dislocation in more than 66% of the cases and adjacent fracture in more than 72% of the cases. CONCLUSION: In our study, the most common site of talar fracture was the body. Current classification systems do not apply to most talar fractures. Talar fracture patterns cannot be characterized with radiography alone. CT is a critical tool for the detection and characterization of talar fractures. There is a high incidence of adjacent fracture and dislocation with acute traumatic talar fractures.

Total ankle arthroplasty: a radiographic outcome study.

OBJECTIVE: Total ankle arthroplasty (TAA) is becoming a popular alternative to arthrodesis for patients with end-stage ankle arthrosis. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TAA and to correlate it with clinical outcome. MATERIALS AND METHODS: In a 9-year retrospective review of patients with TAA, all available ankle radiographs and clinical data were reviewed. Data analysis included descriptive statistics, Fisher exact test, and Kaplan-Meier survival curves for radiographic and clinical survival. RESULTS: Two hundred sixty-two TAAs in 260 patients were reviewed; 55% were in women, and the mean patient age was 61.5 years. The mean radiographic follow-up was 142 weeks, with an average of six radiographs per patient. One hundred sixty-three patients (62.2% of TAAs) developed one or more radiographic complications, including periprosthetic lucency (34.0%), hardware subsidence (24.4%), perihardware fracture (11.1%), syndesmotic screw loosening (10.3%), and screw fracture (6.5%). One hundred nineteen patients (45.4% of TAAs) developed symptoms of ankle pain or instability, and 71 patients (27.1% of TAAs) underwent at least one reoperation. In patients with radiographic complications, 41.7% developed ankle pain and 5.1% developed ankle instability, compared with 23.7% and 2.2%, respectively, of patients with no radiologic complications (p < 0.05). Of the patients with radiographic complications, 33.1% had at least one additional surgery compared with 17.1% of patients without radiographic complications (p < 0.05). CONCLUSION: Radiographic complications are common in patients after total ankle arthroplasty. There is a strong positive association between postoperative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist.

Radial head arthroplasty: a radiologic outcome study.

OBJECTIVE: The purpose of this study is to provide a radiographic outcome assessment of radial head arthroplasty in correlation with clinical outcomes and to determine whether there is an association between certain patient factors and clinical and radiographic outcomes. MATERIALS AND METHODS: A 10-year retrospective review was performed to identify patients with metal radial head arthroplasty. At least two follow-up radiographs were reviewed for each patient and were correlated with clinical information. Statistical analysis included calculation of complication rates, phi coefficient for variable association with complications, and Kaplan-Meier survival. RESULTS: A total of 258 radial head implants in 244 patients were reviewed. The mean patient age was 46 years, with mean follow-up time of 12.8 months. Two hundred nineteen (84.9%) implants were unipolar in design, whereas 39 implants were bipolar. The most common indication for arthroplasty was trauma (94% acute and 2% failed internal fixation). Radiographic abnormalities included nonbridging heterotopic ossification (38.0%), secondary radiocapitellar joint osteoarthritis (27.9%), loosening (19.8%), bridging heterotopic ossification (8.9%), fracture (2.3%), and hardware dislocation (2.7%). Overall, there were 62 second surgeries for either revision or removal. Reasons for second surgery included heterotopic ossification (53.2%), synovectomy or capsulectomy (43.5%), and infection (3.2%). There was a statistically significant association between radiographic complications and the presence of patient symptoms (p < 0.05). There was no association between radiographic or clinical complications with age, sex, side, or type of arthroplasty (R < 0.001). CONCLUSION: There is a positive association between radiographic findings and patient symptoms for postoperative complications after radial head arthroplasty. By 9 months, 50% of implants showed radiographic complications.

Current concepts of shoulder arthroplasty for radiologists: Part 1--Epidemiology, history, preoperative imaging, and hemiarthroplasty.

OBJECTIVE: The purpose of this article is to provide a review of indications for shoulder arthroplasty, describe preoperative imaging assessment, present new and modified designs of shoulder arthroplasty, illustrate normal and abnormal postoperative imaging findings, and review key radiographic measurements. CONCLUSION: Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing shoulder prostheses.

Current concepts of shoulder arthroplasty for radiologists: Part 2--Anatomic and reverse total shoulder replacement and nonprosthetic resurfacing.

OBJECTIVE: The purpose of this article is to provide a review of the indications for shoulder arthroplasty, describe preoperative imaging assessment, present new and modified designs of shoulder arthroplasty, illustrate normal and abnormal postoperative imaging findings, and review key radiographic measurements. CONCLUSION: Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing shoulder prostheses.