Richard H. Gold

The pathology of the joint tissues and its clinical relevance in prosthesis failure.

Thirty-four hip and knee total arthroplasty failures due to infection, loosening, intractable pain and dislocation were examined for synovial and capsular tissue debris. Simiquantitative assessments were made for metal polyethylene, acrylic and cellular debris and inflammation. The most important finding was that in the amounts normally shed into joints, debris particles do not appear to stimulate a polymorphonuclear response. The magnitude of this response correlates best with clinical and/or bacteriological evidence of infection. The quantity of acrylic particles could be correlated with clinical evidence of loosening. Since the correlation between infection and polymorphonuclear leukocytes, debris particles, and the reasons for failure is high, frozen section may aid the surgeon in determining the methods and timing of revision operations.

Magnetic resonance imaging as a tool for evaluation of traumatic knee injuries Anatomical and pathoanatomical correlations

Traumatic injury to the knee remains a diagnostic and therapeutic challenge. Magnetic resonance imaging (MRI) has been applied to musculoskeletal pathoa natomy and has been shown to be an effective tool for definition and characterization of knee pathology. A systematic approach is taken to establish anatomical and pathoanatomical correlations, as well as the role of MRI in the management of knee injuries. Imaging was performed at the UCLA Medical Center using a permanent magnet system and a combination of solenoidal surface coils and thin-section, high-reso lution scanning techniques. Images depict structural anatomical and spatial details of the knee that correlate well with corresponding cadaveric cryosections. To determine pathoanatomical correlations and the effi cacy of MRI, 105 patients with preoperative diagnoses of meniscal tears, anterior and posterior cruciate liga ment tears, tibial plateau fracture, and patella and quad riceps injuries were imaged. Results indicated that for the medial meniscus MRI demonstrated a 95.7% sensitivity, 81.8% specificity, 90% accuracy, 88.2% positive predictive value (PPV), and 93.1 % negative predictive value (NPV). Imaging of the lateral meniscus demonstrated a 75% sensitivity, 95% specificity, 91 % accuracy, 80% PPV, and 94% NPV. MRI of the ACL revealed 100% sensitivity, spec ificity, accuracy, positive and negative predictive values. MRI is a noninvasive tool which uses no ionizing radiation and can accurately define and characterize anatomy and pathoanatomy. This study indicates that MRI in conjunction with clinical evaluation can contrib ute to treatment decision-making processes and assist in preoperative planning. An algorithm demonstrating the potential clinical use of MRI is presented.

IMAGING THE DIABETIC FOOT

Early and accurate diagnosis of infection or neuropathy of the diabetic foot is the key to successful management. Angiopathy leads to ischemia which, in combination with peripheral neuropathy, predisposes to pedal skin ulceration, the precursor of osteomyelitis. Chronic hyperglycemia promotes production of glycosylated end products which accumulate on endothelial proteins, causing ischemia of the vasa nervorum. When combined with axonal degeneration of the sensory nerves, the result is hypertrophic neuroarthropathy. Should the sympathetic nerve fibers also be damaged, the resultant loss of vasoconstrictive impulses leads to hyperemia and atrophic neuroarthropathy. Plain radiography, although less sensitive than radionuclide, magnetic resonance (MR), and computed tomographic examinations, should be the initial procedure for imaging suspected osteomyelitis in the diabetic patient. If the radiographs are normal but the clinical suspicion of osteomyelitis is strong, a three-phase 99mTc-MDP scan or MR imaging is recommended. An equivocal 99mTc-MDP scan should be followed by MR imaging. To exclude osteomyelitis at a site of neuroarthropathy, a 111In white blood cell scan is preferable. To obtain a specimen of bone for bacteriological studies, percutaneous core biopsy is the procedure of choice, with the entrance of the needle well beyond the edge of the subjacent ulcer.

Malignant (fibrous) histiocytoma arising in association with a bone infarct in sickle-cell disease: Coincidence or cause-and-effect?

A patient with homozygous‐S sickle‐cell disease complicated by malignant (fibrous) histiocytoma arising within a tibial medullary infarct is reported. This is the ninth reported case of human sarcoma associated with bone infarct and the first associated with sickle‐cell disease. Evidence for a causal relationship is presented.

Os odontoideum in identical twins: perspectives on etiology

Most authorities favor the hypothesis of an acquired etiology of os odontoideum. We present the cases of identical twin sisters with os odontoideum in association with a congenital partial fusion of the posterior elements of the second and third cervical vertebrae, and discuss the implications. We believe that this is the first report of familial os odontoideum in a context which suggests a genetic etiology.

Disseminated nonossifying fibromas in association with café-au-lait spots (Jaffe-Campanacci syndrome).

A rare case of disseminated nonossifying fibromas of the long bones and jaw in association with cafe-au-lait skin macules is reported. The patient had no evidence of neurofibromatous lesions. The lesions of the patient’s jawbones were called giant cell reparative granulomas by prominent oral pathologists. The history of the terms nonossifying fibroma and giant cell reparative granuloma of the jaw is discussed and their possible or hypothetical equivalence treated.

Measurement of acetabular version on the axiolateral radiograph

There are 3 definitions of acetabular version: true (anatomic) version, planar (radiographic) version, and operative version. Although planar version can be measured on standard radiographs, the measurement may be inaccurate when applied to metal-backed acetabular components. However, another version angle is depicted clearly on an angled, cross-table lateral radiograph of the hip—the axiolateral view, and this angle readily distinguishes anteversion from retroversion. If the angle of the xray beam is known or is standardized, version measured on the axiolateral view can be converted to the other version angles. Nomograms for these conversions are presented. In most cases, acetabular version measured on the axiolateral radiograph closely approximates planar version.

MR imaging of bone marrow in children.

The magnetic resonance (MR) images of the knees and hips of children with systemic diseases involving bone marrow were correlated with their marrow histology and compared with the images of asymptomatic normal children. In normal children the intensity of the MR signal from the bone marrow of the knees and hips was uniform throughout the metaphyses and diaphyses. In contradistinction the MR signal was uniformly diminished for the hypercellular marrow of patients with sickle cell anemia, was similar to normal for the hypocellular hyperfatty marrow of untreated aplastic anemia, and was nonuniform and patchy for leukemic marrow.

Radiography of Gynecomastia and Other Disorders of the Male Breast

Mammographic features of 22 pathologically proved cases reflecting disorders of the male breast are described. Two patterns of gynecomastia were observed: a dendritic pattern seen in association with breast enlargement for 6 months or more, and a more florid triangular pattern, seen in association with breast enlargement of recent onset. Male breast carcinoma may be distinguished from gynecomastia by its eccentric location, spiculation, and, in some cases, calcification or involvement of the skin and nipple. Benign conditions simulating carcinoma included a case of drug-induced gynecomastia and a case of inflamed inclusion cyst.

Hemangiopericytoma of bone

Primary hemangiopericytoma of bone is a rare malignant tumor. Forty‐one cases from the literature were reviewed, and four additional cases are reported. The peak incidence is in the fourth and fifth decades. The pelvis and lower extremities are the most common locations. The radiographic features are nonspecific, although angiography may aid in the diagnosis. Based on a limited number of evaluable cases, the prognosis seems to correlate with the histologic grade of the tumor. Late recurrence and distant metastases are common.