Paraneoplastic musculoskeletal disorders: review and update for radiologists.

Rheumatic paraneoplastic syndromes are rare syndromes that occur at distant sites from the underlying tumor and may involve the bones, joints, fasciae, muscles, or vessels. In the absence of a known tumor, early recognition of a rheumatic syndrome as paraneoplastic permits dedicated work-up for, and potentially early treatment of an occult malignancy. Although there is a continuously growing list of paraneoplastic rheumatic disorders, not all of these disorders have a well-established association with a neoplastic process. The goals of this article are to review the clinical characteristics, diagnostic work-up, and imaging findings of well-documented rheumatic paraneoplastic disorders.

Circulating and Intratumoral Adrenal Androgens Correlate with Response to Abiraterone in Men with Castration-Resistant Prostate Cancer.

PURPOSE: In metastatic castration-resistant prostate cancer (mCRPC) low serum androgens prior to starting abiraterone acetate (AA) is associated with more rapid progression. We evaluated the effect of AA on androgens in castration-resistant prostate cancer (CRPC) metastases and associations of intratumoral androgens with response. EXPERIMENTAL DESIGN: We performed a phase II study of AA plus prednisone in mCRPC. The primary outcome was tissue testosterone at 4 weeks. Exploratory outcomes were association of steroid levels and genomic alterations with response, and escalating AA to 2,000 mg at progression. RESULTS: Twenty-nine of 30 men were evaluable. Testosterone in metastatic biopsies became undetectable at 4 weeks (P < 0.001). Serum and tissue dehydroepiandrosterone sulfate (DHEAS) remained detectable in many patients and was not increased at progression. Serum and tissue DHEAS in the lowest quartile (pretreatment), serum DHEAS in the lowest quartile (4 weeks), and undetectable tissue DHEAS (on-therapy) associated with rapid progression (20 vs. 48 weeks, P = 0.0018; 20 vs. 52 weeks, P = 0.0003; 14 vs. 40 weeks, P = 0.0001; 20 vs. 56 weeks, P = 0.02, respectively). One of 16 men escalating to 2,000 mg had a 30% PSA decline; 13 developed radiographic progression by 12 weeks. Among patients with high serum DHEAS at baseline, wild-type (WT) PTEN status associated with longer response (61 vs. 33 weeks, P = 0.02). CONCLUSIONS: Low-circulating adrenal androgen levels are strongly associated with an androgen-poor tumor microenvironment and with poor response to AA. Patients with CRPC with higher serum DHEAS levels may benefit from dual androgen receptor (AR)-pathway inhibition, while those in the lowest quartile may require combinations with non-AR-directed therapy.

Surgical techniques for management of acromioclavicular joint separations: review and update for radiologists.

Imaging plays a central role in the postoperative management of acromioclavicular (AC) joint separations. There are more than 150 described techniques for the surgical management of AC joint injuries. These procedures can be categorized as varying combinations of the following basic techniques: a) soft-tissue repair, b) trans-articular AC joint fixation, c) coracoclavicular (CC) fixation, d) non-anatomic reconstruction of the CC ligaments, e) anatomic reconstruction of the CC ligaments, f) distal clavicle resection, and g) dynamic muscle transfer. The goals of this article are to describe the basic techniques for the surgical management of AC joint separations with an emphasis on technique-specific complications and postoperative imaging assessment.

Anterior cruciate ligament fixation devices: Expected imaging appearance and common complications.

Anterior cruciate ligament reconstruction is a commonly performed orthopaedic procedure which has increased in frequency over the past decade. There are a variety of fixation devices used to secure grafts within the femoral and tibial tunnels during the reconstruction procedure. An understanding of the expected appearance of the varied hardware utilized for reconstruction graft fixation, and their potential complications is important in the review of post-operative imaging. We describe the most common anterior cruciate ligament reconstruction fixation devices and illustrate their more frequently documented abnormalities.

Radiologic Guide to Surgical Treatment of Kienbock's Disease.

Kienbock's disease, or avascular necrosis of the lunate, is a progressive disease ultimately resulting in end-stage arthrosis of the wrist. Various surgical treatments are available for different Lichtman stages of disease. We review the surgical options and indications, expected radiologic post-operative appearance, as well as detail potential surgical complications, as they relate to Kienbock's disease.

Update on operative treatment of scapholunate (SL) instability for radiologists: part 1-SL ligament repair, dorsal capsulodesis and SL ligament reconstruction.

Scapholunate instability is the most common form of carpal instability. Imaging (especially radiography) plays an important role in the staging, management and post-operative follow-up of scapholunate (SL) instability. The goals of this article are to review the pre-operative staging of SL instability, the surgical options for repair and reconstruction of the SL ligament, along with the normal postoperative imaging findings as well as complications associated with these surgical options.

Characterization and Epidemiology of the Carpal Boss Utilizing Computed Tomography.

Background The carpal boss is an osseous protuberance occurring variably along the dorsum of the second or third metacarpal base, lacking a standardized definition. Aim We sought to characterize the dorsal second and third carpometacarpal joints in the general population on computed tomography (CT) to better define this variant anatomy. Patients and Methods A total of 129 wrist CT studies were reviewed. Note was made of the dorsal second/third carpometacarpal osseous anatomy, the presence of regional bursitis or tenosynovitis, and relationship of the extensor carpi radialis brevis attachment to the base of the third metacarpal. Results Out of the 129 wrists, 106 (82.2%) demonstrated a dorsal protuberance arising from the base of the third metacarpal, in isolation. Out of the 129 wrists, 14 (10.9%) lacked a dorsal protuberance or nonunited ossicle at the level of the second or third carpometacarpal joint. Out of the 129 wrists, 9 (7%) wrists demonstrated more complex anatomy-8 wrists (6.2%) with a dorsal protuberance at the base of the third metacarpal seen in combination with an adjacent nonunited ossicle and/or dorsal protuberance arising from the capitate, and 1 wrist (0.8%) with an isolated ossicle at the base of the third metacarpal. Of these nine wrists, eight (6.2%) demonstrated arthritis at the resultant pseudoarticulation(s). Conclusion The majority of wrists demonstrated an isolated protuberance arising from the dorsal base of the third metacarpal, with a small minority with a nonunited ossicle at this level and/or dorsal protuberance of the capitate. The presence of secondary arthritis (8 out of 129 wrists, 6.2%) may reflect a pain generator. Level of Evidence Cross-sectional study; level 2.

Gadolinium Contrast Enhancement Improves Confidence in Diagnosing Recurrent Soft Tissue Sarcoma by MRI.

RATIONALE AND OBJECTIVES: To determine how utilization of postgadolinium magnetic resonance imaging (MRI) influenced reader accuracy and confidence at identifying postoperative soft tissue sarcoma (STS) recurrence among readers with various levels of expertise. MATERIALS AND METHODS: This retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Postoperative MRI from 26 patients with prior STS resection (13 patients with confirmed recurrence, 13 without recurrence) was reviewed. Four blinded readers of varying expertise (radiology resident, fellow, attending, and orthopedic oncologist) initially evaluated only the precontrast images and rated each MRI for recurrence on a 5-point confidence scale. Assessment was repeated with the addition of contrast-enhanced sequences. Diagnostic accuracy based on confidence ratings was evaluated using the area under the receiver operating characteristic curve (AUC). Changes in confidence ratings were calculated using Wilcoxon signed-rank test. RESULTS: All readers demonstrated good diagnostic accuracy both with and without contrast-enhanced images (AUC >0.98 for each reader). When contrast-enhanced images were made available, the resident recorded improved confidence with both assigning (P = 0.031) and excluding recurrence (P = 0.006); the fellow showed improved confidence only with assigning recurrence (P = 0.015); and the surgeon showed improved confidence in excluding recurrence (P = 0.003). The addition of contrast-enhanced images did not significantly influence the diagnostic confidence of the attending radiologist. CONCLUSIONS: Diagnostic accuracy of MRI was excellent in evaluating postoperative STS recurrence, and reader confidence improved depending on expertise when postgadolinium imaging was included in the assessment.

The Value of Accurate Magnetic Resonance Characterization of Posterior Cruciate Ligament Tears in the Setting of Multiligament Knee Injury: Imaging Features Predictive of Early Repair vs Reconstruction.

Multiligament knee injury (MLKI) represents a complex set of pathologies treated with a wide variety of surgical approaches. If early surgical intervention is performed, the disrupted posterior cruciate ligament (PCL) can be treated with primary repair or reconstruction. The purpose of our study was to retrospectively identify a critical length of the distal component of the torn PCL on magnetic resonance imaging (MRI) that may predict the ability to perform early proximal femoral repair of the ligament, as opposed to reconstruction. A total of 50 MLKIs were managed at Harborview Medical Center from May 1, 2013, through July 15, 2014, by an orthopedic surgeon. Following exclusions, there were 27 knees with complete disruption of the PCL that underwent either early reattachment to the femoral insertion or reconstruction and were evaluated using preoperative MRI. In a consensus fashion, 2 radiologists measured the proximal and distal fragments of each disrupted PCL using preoperative MRI in multiple planes, as needed. MRI findings were correlated with what was performed at surgery. Those knees with a distal fragment PCL length of ≥41mm were capable of, and underwent, early proximal femoral repair. With repair, the distal stump was attached to the distal femur. Alternatively, those with a distal PCL length of ≤32mm could not undergo repair because of insufficient length and as such, were reconstructed. If early surgical intervention for an MLKI involving disruption of the PCL is considered, attention should be given to the length of the distal PCL fragment on MRI to plan appropriately for proximal femoral reattachment vs reconstruction. If the distal PCL fragment measures ≥41mm, surgical repair is achievable and can be considered as a surgical option.

Bilateral pigmented villonodular synovitis of the knee.

Pigmented villonodular synovitis is a disorder resulting in a villous, nodular, or villonodular proliferation of the synovium, with pigmentation related to the presence of hemosiderin. These lesions are almost exclusively benign with rare reports of malignancy. Pigmented villonodular synovitis can occur in a variety of joints and at any age but most often occurs within the knee in the young adult. Pigmented villonodular synovitis is a rare disease entity, and bilateral synchronous or metachronous involvement of a joint is even more uncommon, with few reports previously described in the literature. We present a case of pigmented villonodular synovitis involving both the right and left knee in the same patient, with radiographic imaging, magnetic resonance imaging, photograph and video intraoperative imaging, and pathologic correlation.

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 elbow replacement arthroplasty.

Elbow replacement arthroplasty has become a standard surgical treatment for a variety of diseases of the elbow. First popularized for the treatment of late-stage rheumatoid arthritis and other debilitating forms of joint disease, the current indications have expanded to include primary treatment of elbow trauma. The most commonly used total elbow replacements are linked semiconstrained chromium-molybdenum alloy or titanium alloy prostheses with polyethylene bearing surfaces. These are inserted after resection of the ulnotrochlear joint and typically cemented in place; the radial head is often sacrificed. Modular metal components or massive osteoarticular allografts may be used when there is extensive bone deficiency. Metal radial head replacements are increasing being used for primary fracture treatment and in posttraumatic elbow reconstructive surgery. Long-term outcomes for total elbow replacement are similar to those of other joints, with 10-year survivals of ∼ 90%. Complications specific to elbow implants include infection, aseptic loosening, prosthetic failure, and periprosthetic fracture.

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 hip arthroplasty for radiologists: part 1, features and radiographic assessment.

OBJECTIVE: This article will systematically review radiographic assessment of hip arthroplasty including classifications based on different types and techniques of hip arthroplasty, terminology for prosthetic designs and materials, surgical techniques, and initial and follow-up radiographic assessments. CONCLUSION: Assessment of postoperative hip arthroplasty radiographs is extremely important. It is well known that patients with complications may be asymptomatic, and for this reason, routine radiographic follow-up is recommended for all patients with hip arthroplasty. The foundation of radiologic interpretation of hip arthroplasty is knowledge of the normal appearance of the many different types of prostheses. A standard approach to radiologic reporting should be undertaken.

Current concepts of hip arthroplasty for radiologists: part 2, revisions and complications.

OBJECTIVE: This article reviews the imaging features of revisions and complications of hip replacement arthroplasty and relates these features to the current understanding about how and why these failures occur. CONCLUSION: Short-term failures of hip replacements are most commonly the result of instability and dislocation. Complications ranging from osteolysis caused by granulomatous reaction to particulate wear debris lead to many long-term failures. Attempts to reduce wear debris through changes in design and materials have reduced the rate of some complications but have resulted in new ones. Infection remains a devastating complication that is difficult to resolve.

Pediatric bone imaging: diagnostic imaging of osteoid osteoma.

OBJECTIVE: Osteoid osteomas are benign painful skeletal neoplasms that preferentially afflict young male patients and are readily treatable. This article focuses on the various imaging manifestations of the tumor, while also discussing its clinical presentation, pathogenesis, and treatment. CONCLUSION: Knowledge of the common imaging features of osteoid osteomas will improve our diagnosis of this condition, subsequently facilitating treatment and reducing morbidity.

Radiologic guide to surgical treatment of first carpometacarpal joint osteoarthritis.

OBJECTIVE: The purpose of this article is to provide a radiologic guide to surgical treatment of first carpometacarpal osteoarthritis, a common problem especially in older women. CONCLUSION: Knowledge of the indications, surgical technique, component design, normal postoperative imaging assessment, and imaging findings of complications is important to providing a meaningful radiologic evaluation of patients after first carpometacarpal joint surgeries, including arthroplasty and arthrodesis.

MRI of pediatric patients: Part 1, normal and abnormal cartilage.

OBJECTIVE: Cartilage development has a profound impact on musculoskeletal growth. The objective of this article is to offer insights about the maturation of hyaline cartilage through MRI. We begin by briefly describing the molecular make up of hyaline cartilage. We will then follow with a discussion of the basic principles to apply to optimize hyaline cartilage imaging. The remainder of the article will focus on the MR appearances of the distinct histologic types of hyaline cartilage, normal variations in cartilage development, and the sequelae of cartilage injury on normal skeletal development. CONCLUSION: Knowledge of the normal and abnormal appearances of hyaline cartilage on MRI of pediatric patients will allow readers to avoid mistaking the changes associated with skeletal maturation for pathologic findings.

MRI of pediatric patients: Part 2, normal variants and abnormalities of the knee.

OBJECTIVE: The purpose of this article is to discuss MRI of the pediatric knee and familiarize the reader with conditions encountered in the pediatric population. Clinical scenarios are included to convey important concepts and to orient the learner to normal variants and abnormalities of the pediatric knee. The conditions discussed include, but are not limited to, distal femoral metaphysial irregularity, isolated popliteus tendon avulsion, juvenile idiopathic arthritis, and discoid meniscus. CONCLUSION: The knee is the joint that is most commonly imaged by MRI in children. Injury patterns and signs of other pathologic processes seen in skeletally immature patients are different from those seen in adults. Interpreting pediatric knee MRI studies may be a challenge for those unfamiliar with the evolving patterns of normal development and of the signs of conditions that are more prevalent in children. Through case scenarios, this article describes and provides images that depict conditions commonly encountered in the pediatric knee. Most of the described normal findings and abnormalities are more prevalent in the pediatric population than in adults, and a few of the conditions are, in fact, unique to pediatric patients.