Chondral and osteochondral injuries. Diagnosis and management.

Osteochondral lesions are relatively common and usually occur as a result of trauma. They often are unrecognized acutely and lead to osteochondral defects and eventually osteoarthritis. Detection of these lesions has been aided by bone scan, CT, and MR imaging. Acute osteochondral fragments can be replaced and internally fixed. Chronic osteochondral defects can be treated with several methods designed to stimulate healing by either fibrocartilage or healing by transplantation of bone and cartilage or cartilage alone. The goal of all treatment methods is to provide a stable, congruent joint surface, restore function, and prevent the evolution of osteoarthritis in the injured joint.

Fine-needle aspiration biopsy of sarcomas and related tumors.

BACKGROUND: Largely due to a lack of experience, familiarity, and/or confidence, few centers rely on simple fine-needle aspiration biopsy (FNAB) for the diagnosis of sarcomas and related tumors. METHODS: The authors have reviewed their own experience in more than 200 cases of FNAB of bone and soft-tissue tumors, as well as cases reported in the literature. RESULTS: FNAB has proven to be accurate and useful in 8 consecutive years of clinical experience. No serious complications have occurred. CONCLUSIONS: FNAB is recommended as an integral part of the initial evaluation of amenable orthopaedic tumors, including sarcomas, especially in cases with classic clinical and radiographic findings.

Osteochondritis dissecans of the tarsal navicular bone: imaging findings in four patients.

We report the imaging characteristics of osteochondritis dissecans of the tarsal navicular bone in four cases and review the current literature. Its radiological findings are similar to osteochondritis dissecans found in other sites: focal lucency that disrupts the sharp cortical line, the presence of sclerosis, and cortical depression.

Loose fragments and other debris: miscellaneous synovial and marrow disorders.

Conventional MR imaging evaluation of the knee focuses mainly on the effects of acute trauma and degenerative conditions. Numerous other conditions that affect the knee may mimic clinical characteristics of common traumatic and degenerative disorders. Synovial and marrow abnormalities are frequently encountered and often unsuspected on routine MR imaging studies of the knee. This article presents the MR imaging appearance of the normal synovium, bone marrow, and commonly encountered abnormalities of these structures.

Longitudinal tibial stress fractures: a report of eight cases and review of the literature.

PURPOSE: We present the imaging features of longitudinal stress fractures in eight patients and evaluate the literature to determine which tests are most useful for making this diagnosis. METHOD: Three musculoskeletal radiologists retrospectively reviewed eight cases of longitudinal tibial stress fractures presenting between 1988 and 1994. Reports on 36 cases, cited in the literature between 1960 and 1996, also were reviewed. Imaging modalities used and characteristic imaging features were noted. RESULTS: Plain radiographs had a characteristic appearance in approximately 28% of patients. Initially, plain films were negative, and in most cases, they eventually showed characteristic radiographic features. However, 25% of cases failed to demonstrate a plain film abnormality, with the diagnosis made by other modalities. CT or MRI is often diagnostic, and longitudinal stress fractures have characteristic imaging features with each modality. While sensitive, bone scan has lower specificity than either CT or MRI. CONCLUSION: Longitudinal stress fractures have characteristic imaging features, and familiarity with these features is necessary for timely and efficient diagnosis, avoiding morbidity due to delay or use of unnecessary tests.

Slipped capital femoral epiphysis.

SCFE is the most common hip abnormality in adolescence. The subsequent development and severity of degenerative changes is related to the degree of slippage and to delay in diagnosis. Awareness of this diagnostic possibility in the population at greatest risk and knowledge of subtle and early radiographic findings will allow prompt diagnosis and treatment of SCFE. Follow-up radiographic examination should be used to evaluate for physeal fusion and any complications, including progression of the slip, hardware complications, chondrolysis, avascular necrosis, and secondary osteoarthritis.

Hand and wrist.

Some basic principles of orthopedic management of common conditions of the hand and wrist have been presented. These basic principles and an awareness of the potential complications should aid radiologists in evaluation of postoperative films. The interested reader is referred to Green's Operative Hand Surgery and Chapman's Operative Orthopaedics for more detailed information.

Noninvasive staging of lung cancer. Indications and limitations of gallium-67 citrate imaging.

The results of evaluation of the hila and mediastinum with 67Ga scans are contradictory, as are the recommendations by different investigators on the use of 67Ga scintigraphy in the clinical evaluation of patients with primary lung carcinoma. Nevertheless, the economy and logistic simplicity of evaluating local and distant metastases with a single imaging procedure are attractive, especially because the symptoms may not enable the physician to make a correct identification of the organ systems affected by metastases. Neumann and Hoffer state that "at present conventional Ga-67 scanning techniques cannot be recommended for preoperative staging of mediastinal lymph node metastases in lung cancer patients." According to Waxman, 67Ga scintigraphy, relative to other imaging modalities, is a sensitive indicator of hilar spread of a tumor. However, because of the normally high background activity within the sternum and spine, mediastinal abnormalities may be poorly detected. Since most pulmonary tumors metastasize via regional nodes to the pulmonary hilum and then to the mediastinum, the high sensitivity for the detection of pulmonary hilar abnormalities and the high specificity for detection of mediastinal lesions suggest that gallium scintigraphy is a valuable adjunctive test when used appropriately. The results obtained locally are probably the best guide for individual physicians in the selection of diagnostic tests for their patients. Gallium scans may thus be helpful in the clinical evaluation of patients with lung cancer. Although gallium scans identify mediastinal node involvement, there is considerable controversy over the relationship between the sensitivity and specificity of the method. By detecting distant extrathoracic metastases, the 67Ga scan may identify a small group of patients who can be spared a needless operation. Gallium scanning fails specifically for metastases within the brain; thus, it does not supplant CT scans of the brain and it is less sensitive than bone scans in detecting osseous metastases. Gallium scanning of patients with small-cell lung cancer is not useful in the selection of therapy but does become important from a prognostic standpoint. Patients with extrathoracic involvement by small-cell carcinoma of the lung are known to have limited survival times compared with those of patients with thoracic involvement alone. In identifying patients with extensive disease, the oncologist is thus provided with prognostic information that may be useful in the counseling of the patient and the patient's family.