An irreducible knee dislocation: a case report.

An 8-year-old man presented after sustaining an injury during a fall. A closed reduction attempt failed, and after several tests, an open reduction was performed. With posterolateral dislocation of the knee, there can be anterior cruciate ligament, posterior cruciate ligament, and medial collateral ligament disruption. At the 6-month (final) follow-up, the patient had no subjective pain or instability. With this type of injury, the approach can be conservative monitoring or repair of all of the ligaments. Because of the age and activity level of our patient, we opted for repair of the medial collateral ligament initially with the possibility of late anterior cruciate ligament and/or posterior cruciate ligament reconstruction.

Intraosseous pneumatocyst of the iliac bone.

Intraosseous pneumatocyst of the iliac bone is usually an innocuous incidental finding with characteristic radiographic features. Because this entity is uncommon and has not been described in the orthopaedic literature, many orthopaedic surgeons are unfamiliar with the entity. Three cases of intraosseous pneumatocyst of the iliac bone are presented to illustrate some of the imaging features to assist in recognizing it for what it is: an innocuous incidental finding that should not prompt invasive procedures such as a biopsy.

Magnetic resonance imaging of the musculoskeletal system. Part 4. The knee.

Since its introduction to musculoskeletal imaging in the early 1980s, magnetic resonance imaging has proven to be an excellent technique for evaluating patients with knee problems. Studies have shown it to be accurate in the identification of abnormalities of the menisci, ligaments, patellofemoral joints, and other soft tissue and osseous structures in the knee. The main advantages of magnetic resonance imaging are its noninvasive nature and its high accuracy and negative predictive value in evaluating the menisci and anterior cruciate ligament. Magnetic resonance imaging has been shown to be useful in the detection and diagnosis of various traumatic and nontraumatic knee abnormalities. It has also proved useful in the diagnosis of occult or unsuspected bone lesions. Magnetic resonance imaging can therefore help in the selection of those patients who need therapeutic arthroscopy. There is evidence that magnetic resonance imaging of the knee is a cost effective screening technique when used in conjunction with the clinical findings in patients who are candidates for arthroscopy. Magnetic resonance imaging of the knee is still a relatively expensive modality.

Ultrasonography in the management of painful hips in children.

The decision to aspirate a painful hip joint is often based on history, physical, and laboratory findings. The purpose of this study is to determine whether ultrasound is helpful in making decisions to aspirate a painful hip joint in children. The anterior capsular distance was determined in 10 children with painful or irritable hips. This anterior capsular distance is 2 to 4 mm in most hips. A side difference of 2 mm or more is considered a significant capsular distension. Based on these criteria and clinical parameters, 3 hips were aspirated, and 7 were observed without aspiration. None of the 7 hips subsequently required further diagnostic workup or treatment and all have had a satisfactory outcome. Ultrasound is a reliable method to detect capsular distension or joint effusion. It helps significantly in making the decision as to "when to aspirate" a painful or irritable hip joint.

Synovial osteochondromatosis.

Primary or idiopathic synovial osteochondromatosis is an uncommon condition probably caused by synovial metaplasia and typically resulting in multiple calcified periarticular bodies. Synovial osteochondromatosis also may occur secondary to other joint disorders. This article reviews the pathogenesis, pathologic features, clinical features, and radiologic imaging of synovial osteochondromatosis. The differentiation of synovial osteochondromatosis from other conditions associated with periarticular calcified bodies is discussed.

Nuclear medicine studies of aging: X. Relationship of liver and spleen lengths at age 65 years and older.

For 3 groups of patients aged 65 years or greater, liver and spleen lengths were measured from calibrated radiocolloid images. Length relationships between liver (L) and spleen (S) were examined in terms of S as a function of L, as well as (S/L) and (L-S) vs S or L. Liver and spleen lengths were the least well correlated in these patients. The S/L ratio vs S produced the most significant correlation in all 3 groups. This suggests a complex but describable relationship between liver and spleen lengths in the overall aging population, and provides a baseline for comparing the effects of various diseases on S and L.