Analysis of the heel pad fat in rheumatoid arthritis.

The heel fat pad is organized, both in structure and in composition, to bear the stresses and strains of normal activities and to permit pain-free weightbearing. The fatty acid composition of heel pads in 11 patients with rheumatoid arthritis, a disease process frequently associated with heel fat pad atrophy, was analyzed using gas-liquid chromatography and was compared with that of patients without systemic disease. The heels of patients with rheumatoid arthritis demonstrated a significant change in the composition of saturated fatty acids when compared with heels of nonrheumatoid patients. This composition reflects an increased fat viscosity, which decreases the ability of the heel to absorb and dissipate the energy generated during ambulation. This factor could cause degeneration of the heel septal system, with resulting fat pad atrophy.

Histology and histomorphometric analysis of the normal and atrophic heel fat pad.

Light and electron microscopy was used for a histologic examination of normal heel fat pads and atrophic heel fat pads from patients with peripheral neuropathies. Histomorphometric analysis revealed an average 30% smaller mean cell area and 16% smaller mean cell diameters in the atrophic pads compared with the normal heel fat pads. Septal walls in the atrophic fat pads were often fragmented and approximately 75% wider than normal. Perineural fibrosis was also found in the atrophic heel fat pads. The Verhoeff elastic staining technique was used to determine the relative percentage of collagen to elastic tissue within the septae. No significant differences were noted between the normal and atrophic heels. The ultrastructure of the adipocytes from the normal and atrophic heel pads was similar to those found in abdominal subcutaneous fat. Lipid droplets of variable size and density thin the center of the adipocyte were surrounded by a thin border of cytoplasm. The interphase between adipocytes contained fine collagen and elastic fibers.

Fatty acid composition of normal and atrophied heel fat pad.

Capillary gas-liquid chromatography was used to analyze the fatty acid composition of normal heel fat pads from subjects without systemic disease (N = 8) and atrophied heels from patients with diabetic peripheral neuropathy (N = 4), rheumatoid arthritis (N = 1), peripheral vascular disease (N = 1), and hereditary sensory neuropathy (N = 1). In the normal subjects, the fatty acid composition of subcutaneous abdominal fat was also obtained for comparison. Three saturated fatty acids (myristate, palmitate, and stearate) and four unsaturated fatty acids (palmitoleate, oleate, vaccenate, and linoleate) comprised over 90% of the total fatty acid composition. Higher percentages of unsaturated fatty acids and lower percentages of saturated fatty acids were found in the normal heel fat pads when compared to subcutaneous abdominal fat. The increase in the ratio of unsaturated fatty acids to saturated fatty acids (4.4 versus 2.5, P < .01) may decrease triglyceride viscosity and enhance the biomechanical efficiency of the heel fat pad. Though the number of patients is small, no statistically significant compositional differences were noted between the heel fat from normal subjects and from subjects with peripheral neuropathies, rheumatoid arthritis, or peripheral vascular disease. However, the heel fatty acid composition of the one subject with a hereditary sensory neuropathy was less unsaturated and more saturated than normal with a ratio of unsaturates to saturates similar to that of the abdomen (2.8).

Magnetic resonance imaging of anomalous leg muscles: accessory soleus, peroneus quartus and the flexor digitorum longus accessorius.

Since the availability of magnetic resonance imaging (MRI), the suspected diagnosis of an accessory muscle of the lower extremity can now be confirmed without the need for invasive procedures. The accessory soleus, peroneus quartus, and flexor digitorum longus accessorius are anomalous muscles of the lower extremity that can be diagnosed by MRI. These accessory muscles are probably more common than once thought and can now be easily distinguished from other space occupying lesions that can occur around the ankle. MRI of these anomalous muscles enables one to make a definitive diagnosis without a biopsy. In those symptomatic patients, the origins and insertions of these accessory muscles can be accurately evaluated by MRI prior to any anticipated surgical intervention.

Monteggia type I equivalent lesion: diaphyseal ulna and proximal radius fracture with a posterior elbow dislocation in a child.

A rare type I equivalent Monteggia lesion in a child, diaphyseal ulna and proximal radius fracture with a posterior elbow dislocation, is described, as well as the probable mechanism of injury. An excellent result was obtained with nonoperative treatment.

Irreducible fracture of the proximal tibial physis in an adolescent.

Fracture of the proximal tibial physis is a rare injury. This paper reports an unusual case of a 13-year-old boy who sustained a displaced Salter II proximal tibial fracture. Closed reduction could not be achieved. An open reduction revealed interposed periosteum in the fracture site.

Tumoral calcinosis. Case presentation and review.

Tumoral calcinosis is a disease of unknown etiology with a greater prevalence among blacks, in which subcutaneous calcifications are found around the extensor surface of the hip, shoulder, hand and occasionally the knee. They must be differentiated from other more common causes of calcification.

Orthopaedic considerations in obstetric brachial plexus palsy.

Obstetric brachial plexus palsies are seen in orthopaedic practice today despite improved obstetric care. The incidence is believed to be 0.35 to 0.87 cases per 1,000 live births. The pathomechanics of these injuries are not fully understood, although numerous risk factors have been identified. Large birth weight, breech presentation, shoulder dystocia, and forceps-assisted deliveries have all been implicated. No one standard treatment modality exists. Therefore, the treating orthopaedist must be familiar with this entity and with the various accepted treatment approaches in order to formulate the appropriate therapy for a particular patient.