Radiological features of superomedial iliac insufficiency fractures: a possible mimicker of metastatic disease.

OBJECTIVE: Pelvic insufficiency fractures are common in elderly patients. Because both osteoporosis and metastatic disease occur in similar patient populations, insufficiency fractures may be mistaken for metastatic foci. Although the ilium is not an uncommon location for metastases, insufficiency fractures rarely involve the ilium. The radiological features of insufficiency fractures adjacent to the sacroiliac joint (superomedial ilium) have not been well described. We describe the computed tomography (CT), magnetic resonance (MR), and positron emission tomography (PET) imaging findings of these rare fractures. MATERIALS AND METHODS: Six patients (five female, one male; mean age 66 years, age range 47-83 years) with iliac insufficiency fractures adjacent to the sacroiliac joint were identified following retrospective review of a clinical database. Imaging studies, including CT (n = 4), MR (n = 3), and PET (n = 2) were reviewed by two radiologists. Tissue biopsy result was available in one patient. RESULTS: CT demonstrated subtle fracture lucency (n = 2) or linear sclerosis (n = 3) adjacent to the sacroiliac joint; MR marrow changes adjacent to the sacroiliac joint demonstrated a low T1, high T2 signal intensity line (n = 2), or a low T1 and low T2 signal intensity line (n = 1). Fractures were fluorodeoxyglucose avid (n = 2) with average SUV(max) 2.2. Iliac fractures were bilateral in three patients; additional pelvic insufficiency fractures were present in one patient. In one patient, CT-guided biopsy showed no evidence of malignancy. CONCLUSION: Recognition of the radiological characteristics of iliac insufficiency fractures is important in order to distinguish them from malignancy. The presence of additional pelvic fractures in characteristic locations in the setting of osteoporosis may help to confirm the diagnosis.

Diffuse FDG shoulder uptake on PET is associated with clinical findings of osteoarthritis.

OBJECTIVE: Our objective was to examine the degree and pattern of (18)F-FDG uptake within the shoulder as a potential marker of joint inflammation or injury. SUBJECTS AND METHODS: Twenty-four patients undergoing (18)F-FDG PET for clinical oncologic assessment completed questionnaires regarding history of shoulder disease, trauma, pain, and/or functional impairment. Thorough physical examination of the shoulder was performed. A clinical diagnosis of specific shoulder derangement or normal was established for each patient. PET scans were evaluated blindly by a nuclear medicine physician and a musculoskeletal radiologist qualitatively for location, distribution, and intensity of shoulder uptake. Standardized uptake values (SUV) were measured. RESULTS: Twenty-one patients had shoulder PET findings. Fourteen had clinical findings consistent with a specific diagnosis in the PET-positive shoulder. The remaining seven PET-positive patients were clinically normal. Three recognizable patterns of uptake were appreciable. Eight of 10 patients with diffuse uptake had findings of osteoarthritis (n = 7) or bursitis (n = 1). Two of four patients with focal greater tuberosity uptake had findings of rotator cuff injury. Two of four patients with focal glenoid uptake had findings of frozen shoulder. SUV showed a positive correlation with subject age (p < 0.01), but no association with clinical findings was identified. CONCLUSION: The pattern of FDG uptake within the shoulder may point to specific clinical entities. While focal uptake is less reliably related to clinical findings, diffuse uptake is associated with signs and symptoms of osteoarthritis or bursitis.

Non-contrast MR imaging of the glenohumeral joint. Part II. Glenohumeral instability and labrum tears.

MR imaging of the shoulder without contrast is frequently used for evaluation of glenohumeral instability in spite of the popularity of MR arthrography. With proper imaging technique, familiarity with normal anatomy and variants as well as knowledge of the expected pathologic findings high diagnostic accuracy may be achieved.

Non-contrast MR imaging of the glenohumeral joint. Part I. Normal anatomy.

MR imaging of the shoulder without contrast is frequently used for evaluation of glenohumeral instability in spite of the popularity of MR arthrography. With proper imaging technique, familiarity with normal anatomy and variants as well as knowledge of the expected pathologic findings high diagnostic accuracy may be achieved.

Advanced imaging of tuberculosis arthritis.

Musculoskeletal manifestations are seen in approximately 3% of tuberculosis (MTb) cases, more commonly in the spine. Extra-axial bone and joint MTb is infrequently encountered in the West. In the last decade, public health strategies for control of MTb have been so successful in industrialized countries that many clinicians are unfamiliar with the range of extrapulmonary manifestations of MTb and therefore hold a low index of suspicion for MTb in the diagnosis of bone and joint infection. MTb, however, persists as a serious and significant cause of musculoskeletal pathology in many parts of the world and for specific patient cohorts in industrialized countries. Knowledge of the patient groups at risk and awareness of the varied osteoarticular manifestations of MTb are essential for timely diagnosis and intervention and potential cure.

Imaging of the elbow in the overhead throwing athlete.

Elbow injuries in athletes who perform overhead throwing motions often present diagnostic challenges because of the undue stresses and often chronic, repetitive patterns of injury. Accurate and efficient assessment of the injured elbow is essential to maximize functional recovery and expedite return to play. Radiographic evaluation should be tailored to the specific injury suspected and requires a thorough understanding of normal anatomic relationships as well as familiarity with common injuries affecting these athletes.

Osteoblastoma-like osteosarcoma of the distal tibia.

We report a case of a 14-year-old boy with an intracompartmental lytic lesion with poorly defined margins in the right distal tibia that was originally treated with curettage and bone grafting. Histologic examination showed an osteoblastic tumor with unusual features, which was found on consultation to be an osteoblastoma-like osteosarcoma, a rare, low-grade variant of osteosarcoma. Subsequently, the patient underwent en bloc resection of the distal tibia, which was replaced with vascularized bone graft and followed by chemotherapy. Two years later, he is alive with lung metastases.

Pelvic presentation of a hip joint ganglion: a case report.

Ganglia may be found near any joint. The hip joint is one location where these lesions have been reported. In most instances the ganglia found around the hip are small, deep-seated, and not palpable. Palpable ganglia are commonly larger and present as a groin mass. We report a ganglion cyst that was not palpable due to its intrapelvic location.