Growth disturbances after distal tibial physeal fractures.

Twenty-four patients with distal tibial growth disturbance were reviewed. Disturbances were classified as physeal bar (prior to deformity), angular, linear or combined deformities. Treatment consisted of osteotomy in fourteen, epiphyseodesis in seven, excision of bony bar in two, and observation in one patient. Follow up was an average 36.6 months (range 4-129 months) after treatment of growth disturbance. The age at time of injury was 10.4 years of age average (range 3-15 years). There were 12 SH2, 2 SH3, 7 SH4, and 3 SH5 distal tibial physeal fractures. Thirteen of 15 fractures considered high energy and only 1 of 9 fractures considered low energy resulted in angular deformity. Angular and linear deformities presented an average 46 months (range 12-120 months) and physeal bars at an average 14 months (range 6-25 months) after injury. Patients with a delay in presentation of growth disturbance greater than 24 months had angular deformities in 92% compared with 33% in children presenting less than or at 24 months. Treatment based on type of deformity, age at time of injury, and growth remaining was considered successful in 83%. Patients with angular or linear deformities were more likely to present late, have high energy injuries, be male patients and have Salter-Harris types IV and V. Early diagnosis and treatment of growth disturbance can prevent severe deformity.

Fibrous lesion of the distal femur associated with angular deformity.

Unilateral femoral angulation is uncommon. We describe two children with unilateral progressive distal femoral varus and limb-length discrepancy. These deformities were associated with a fibrous lesion involving the medial aspect of the distal femoral metaphysis. Both patients were 15 to 16 months old. In both, the deformity was progressive, resulting in excisional biopsy and osteotomy. The gross and microscopic appearance of both lesions was similar, and the histology was dense fibrous connective tissue. The patients' femoral alignment was maintained at follow-up of a minimum of 16-36 months. The etiology of these lesions is unknown; they are associated with progressive deformity and appear to respond well to surgical intervention.

A simple method to measure compartment pressures using an intravenous catheter.

A simple method was investigated to measure compartment pressures using 16-ga intravenous catheters with or without side ports attached by arterial line tubing to a pressure transducer. Pressure measurements from the experimental catheters were within 4 mm Hg of the slit catheter for 99% of all readings, and pressure measurements from the Stryker device were within 5 mm Hg of the slit catheter for 95% of all readings. The addition of one or two side ports to the experimental catheters did not alter the pressure readings. This method is comparable in accuracy to the slit catheter and in simplicity to the Stryker device.

Hormonal modulation of ionic permeability in human red blood cells.

It has previously been reported that both exogenous adenosine cAMP analogs and forskolin-induced elevations in intracellular cAMP concentrations selective increase relative ionic chloride permeability in normal human red blood cells (RBC). A similar selectively increase in relative ionic chloride permeability was observed in untreated uremic subjects in whom endogenous RBC cAMP concentrations are chronically elevated. To detect which hormones might modulate RBC cAMP and ionic permeabilities, RBC were exposed to norepinephrine, epinephrine, and parathyroid hormone. Thereafter, RBC cAMP concentrations were measured by RIA and relative ionic permeabilities were determined in human RBC ghosts with the potential sensitive fluorescent probe diS-C3-(5). In ghosts prepared from normal RBC, norepinephrine and epinephrine significantly increased intracellular cAMP concentrations; in these ghosts, relative ionic chloride permeability (permeability of chloride/permeability of potassium (PCI/PK)), but not PNa/PK (permeability of sodium/permeability of potassium), was significantly increased. In contrast, exposure to parathyroid hormone did not affect either cAMP concentrations or relative ionic permeabilities. These results are consistent with the presence of adrenergic receptors and the absence of parathyroid hormone receptors in RBC. These studies demonstrate that hormonally induced changes in cAMP can modulate RBC relative ionic chloride permeability and suggest that, in uremic RBC, increased relative ionic chloride permeability could be consequent to elevated plasma levels of epinephrine or norepinephrine.