Synovial chondromatosis of the hip evaluation with air computed arthrotomography

Four patients with primary synovial chondromatosis of the hip were evaluated with air or double contrast computed arthrotomography. Air computed arthrotomography was an easy and accurate method of diagnosing the disease and delineating its anatomic extent. The use of air as a sole contrast agent allowed noncalcified chondromatous nodules to be identified. It prevented faintly calcified nodules from being obscured by positive contrast, and was a better means of assessing the narrow portions of the hip joint.

Accurate diagnosis of this disease and its extent was demonstrated using air computed arthrotomography. This method provided the most complete preoperative data for the orthopaedic surgeon.     

Magnetic resonance imaging of intraosseous lipomas: a radiologic-pathologic correlation

Four patients with intraosseous lipomas were studied with magnetic resonance imaging. The imaging features and histology of each tumor were compared. Magnetic resonance imaging was very helpful in establishing a pathologic diagnosis. If a severe degree of involution was present, then the magnetic resonance findings could be ambiguous, making diagnosis more difficult.     

Complications after limb salvage surgery

Orthopedic oncology patients gain a chance at an active, disease-free life through the use of limb salvage surgery. This goal is reached with meticulous technique, detailed operative planning, and the use of endoprosthetic replacements and/or bone grafting. This article will address the late complications of limb salvage surgery, including aseptic loosening, prosthetic fracture and dislocation, as well as graft fracture and nonunion.     

Primary alveolar soft part sarcoma of fibula demonstrating ASPL–TFE3 fusion: a case report and review of the literature

Alveolar soft part sarcoma is a rare soft tissue tumor typically affecting young adults. These tumors are most often seen in the deep soft tissues of the extremities and patients generally present with advanced disease. Primary bone involvement is extremely rare and has only been reported in seven cases. This is the first case of alveolar soft part sarcoma in bone documenting the ASPL-TFE3 gene product. Herein, we report a rare presentation of alveolar soft part sarcoma presenting as a primary bone neoplasm involving the proximal fibula in a 41-year-old woman.     

Connecting Teens to Caring Adults in a School-Based Health Center: A Case Study

The traditional medical care system is generally unable to provide the broad health and wellness services needed by many adolescents, especially those from low-income and racial/ethnic minority communities. Using a theoretical framework adapted from Bronfenbrenner’s ecological model of multiple influencers, this case study examined how a school-based health center was able to provide a network of connections for adolescents to caring adults within the school and the local community. Contributors to this network were the creation of a student-centered community with access to adolescent-friendly services, providers acting as connectors, and care of the whole adolescent.     

Avascular necrosis of bone in human immunodeficiency virus infected patients

The objective of this article was to delineate the causes of avascular necrosis (AVN) in patients with human immunodeficiency virus (HIV). HIV-infected patients with pain in large joints were prospectively screened. Patients had radiographs and magnetic resonance imaging of their affected joints. Serum lipids, anticardiolipin antibody levels (IgG, IgM), and hemoglobin electrophoresis were performed on all patients who had radiographic studies. Medical records were screened for factors known to predispose for AVN. Eight patients completed the protocol, and five patients had AVN in seven joints. No common laboratory abnormality was identified in the patients with AVN. All of the patients with AVN had a history of steroid use; four of five patients having taken steroids for HIV-related diseases. The cause of AVN does not appear to be directly related to the disease, but to steroid treatment for manifestations of the disease.     

The influence of flip angle on the magic angle effect

Objective. To assess the impact of flip angle with gradient sequences on the ”magic angle effect”. We characterized the magic angle effect in various gradient echo sequences and compared the signal- to-noise ratios present on these sequences with the signal-to-noise ratios of spin echo sequences. Design. Ten normal healthy volunteers were positioned such that the flexor hallucis longus tendon remained at approximately at 55° to the main magnetic field (the magic angle). The tendon was imaged by a conventional spin echo T1- and T2-weighted techniques and by a series of gradient techniques. Gradient sequences were altered by both TE and flip angle. Signal-to-noise measurements were obtained at segments of the flexor hallucis longus tendon demonstrating the magic angle effect to quantify the artifact. Signal-to-noise measurements were compared and statistical analysis performed. Similar measurements were taken of the anterior tibialis tendon as an internal control. Results and conclusions. We demonstrated the magic angle effect on all the gradient sequences. The intensity of the artifact was affected by both the TE and flip angle. Low TE values and a high flip angle demonstrated the greatest magic angle effect. At TE values less than 30 ms, a high flip angle will markedly increase the magic angle effect. Received: 6 December 1999 Revision requested: 31 March 2000 Revision received: 22 May 2000 Accepted: 23 May 2000     

Osteomyelitis originating in and around bone infarcts: giant sequestrum phenomena

OBJECTIVE: We describe four cases of osteomyelitis that occurred in and around foci of preexisting osteonecrosis in the medullary cavity. Although sequestration is a well-known complication of osteomyelitis, there is little information known about infection occurring in proximity to large regions of already necrotic bone. CONCLUSION: Osteomyelitis and bone infarction can be seen in the same patient population. Medullary infarcts may function as sequestra, predisposing patients to osteomyelitis and soft-tissue infection.     

Muscle infarction in a 13 year-old female with type 1 diabetes mellitus of short duration

A 13 year-old female with an 11-month history of type 1 diabetes mellitus (DM) was admitted to the hospital with a muscle infarction. Diagnosis of this rare complication of DM was suggested by clinical presentation, magnetic resonance imaging (MRI) and muscle biopsy. While diabetic muscle infarction (DMI) has been previously described in adult patients with long-standing DM associated with microangiopathy, it is an unexpected finding in this clinical setting.