Axial computed tomographic anatomy of the foot: Part III. Forefoot.

Cross-sectional osseous and soft tissue anatomy of the human forefoot as demonstrated by high resolution computed tomography (CT) is described. This report serves an important baseline function because CT may be useful for the evaluation of a variety of forefoot disorders in the clinical setting.

Axial computed tomographic anatomy of the foot. Part I: Hindfoot.

Osseous and soft tissue anatomy of the human hindfoot is presented as visualized on high-resolution axial computed tomography (CT). Radiologic-pathologic correlation with the use of a cadaver specimen and contiguous CT sections 1.5 mm. thick was performed for structural identification. The foot of a healthy senior citizen was scanned by using 5.0-mm. slice thickness. Because of the proven and potential capabilities of CT in the diagnosis of hindfoot disorders, this report serves as an important standard for comparison with clinical studies.

Axial computed tomographic anatomy of the foot. Part II: Midfoot.

Osseous and soft tissue anatomy of the human midfoot is presented as visualized on high resolution axial computed tomography (CT). Because of the proven and potential capabilities of CT in the diagnosis of midfoot disorders, this report serves as an important standard for comparison with clinical studies.

The adult hip: an anatomic study. Part I: the bony landmarks.

A comprehensive anatomic, pathologic and radiographic study of the adult hip was undertaken to define bony landmarks which, when altered, are reliable indicators of disease. Methodology included radiography of cadaveric specimens and analysis of over 300 anteroposterior (AP) radiographs of "normal" adult hips. This information was applied to clinical situations with the following conclusions: (a) The diagnosis of protrusio acetabuli is warranted if the acetabular line projects medial to the ilioischial line by 3 mm or more in men and by 6 mm or more in women. (b) In acetabular trauma, an AP and two oblique radiographs (30 degrees anterior oblique and 30--45 degrees posterior oblique) are required for complete evaluation. (c) Characteristic alterations in the joint space allow accurate diagnosis of disease.

The adult hip: an anatomic study. Part II: the soft-tissue landmarks.

A comprehensive anatomic, pathologic, and radiographic study was undertaken to define reliable soft-tissue landmarks about the hip. Methodology included an analysis of 300 "normal" adult hip radiographs, tissue maceration, cadaveric intra-articular injection studies and review of selected clinical cases. Results, when applied to clinical situations, indicate: (a) The iliopsoas and "capsular" fat planes are poor indicators of small to moderate amounts of intra-articular fluid in the adult. (b) The "capsular" fat plane is not associated with the joint capsule, but in fact is a fat plane between two muscle bundles anterior to the articulation. (c) Distinct soft-tissue planes are available for dissemination of fluid from the hip joint. These include the iliopsoas bursa, which may distend in association with articular disease, and the fat plane of the obturator externus muscle.

Calcaneal abnormalities in articular disorders. Rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and Reiter syndrome.

The calcaneus of normal control patients, and those with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and Reiter syndrome was studied. Pathological abnormalities of the plantar aponeurosis, Achilles tendon, and retrocalcaneal bursa account for the radiographic alterations. In normal individuals, lateral radiographs show the thickness of the Achilles tendon to be not greater than 8 mm; the retrocalcaneal bursa creates a radiolucency which extends at least 2 mm below the superior surface of the calcaneus. In patients with any of these 4 articular disorders, Achilles tendinitis produces thickening of the tendon, and retrocalcaneal bursitis obliterates the normal radiolucency.

The plantar compartments of the foot: a roentgen approach I. Experimental observations.

The integrity of the plantar muscle compartments of the human foot were studied utilizing radiographic and anatomic techniques in an attempt to determine potential pathways for spread of soft tissue infection. One of three major plantar muscle compartments--medial, intermediate or lateral--in 24 unembalmed cadaveric feet was injected percutaneously under fluoroscopy with radiopaque Methyl-methacrylate using both manual and automatic injection techniques with pressure callibration. Following freezing, specimens were sectioned, radiographed, and dissected or partially macerated. Frequency and patterns of extravasation of contrast material were documented and recorded. The results obtained support the concepts that: a) there are three distinct plantar muscle compartments that are maintained by intermuscular septae; and b) there are potential communicating pathways provided by specific anatomic structures.

The sesamoid bones of the hands and feet: participators in arthritis.

The sesamoids generally appear as small ovoid bones adjacent to articulations or at sites where tendons are angled about osseous surfaces. At either location they participate in joint afflictions, the pattern of abnormality being remarkably constant and predictable. Sesamoids may demonstrate osseous erosion in rheumatoid arthritis, bony proliferation or "whiskering" in rheumatoid variants, joint space narrowing and bony ankylosis in septic arthritis, and eburnation and osteophyte formation in osteoarthritis and diffuse idiopathic skeletal hyperostosis. These changes become particularly important when they occur in the absence of significant adjacent articular disease. In these instances, recognition of sesamoid abnormalities allows accurate radiographic diagnosis.

Postoperative heterotopic ossification in patients with ankylosing hyperostosis on the spine (Forestier's disease).

Heterotopic ossification following hip surgery occurred in three patients with ankylosing hyperostosis of the spine. No technical difficulty during surgery was encountered in these individuals. The occurrence of this postoperative complication, coupled with the appearance of bony outgrowths at sites of ligament attachment throughout the axial and extra-axial skeleton in patients with ankylosing hyperostosis of the spine, suggests the presence of an underlying ossifying diathesis, diffuse idiopathic skeletal hyperostosis (DISH). A significant number of patients with DISH possess the second segregant series antigen, HLA-B27, a feature they share with individuals with other arthropathies characterized by abundant ossification; this gene may be closely related to one which influences bone formation. The possible association of postoperative heterotopic ossification and ankylosing hyperostosis of the spine indicates that a radiographic examination of the vertebral column in patients undergoing hip surgery may be a useful screening procedure.