Biomechanical analysis of hindfoot fixation using an intramedullary rod.

To measure the stiffness of the hindfoot when fixed with an intramedullary rod placed in a retrograde manner, two biomechanical experiments were carried out on five matched pairs of cadaveric below knee specimens. Experiment 1: In the right leg of each pair, an intramedullary rod was placed in a retrograde fashion through the calcaneus, talus, and into the tibial intramedullary canal. Biomechanical testing was done to determine hindfoot stiffness, with and without distal and proximal transverse interlocking screws. The uninstrumented left leg of each pair was tested as a control. Experiment 2: A series of similar biomechanical experiments were done on the same specimens to determine the effect on hindfoot stiffness of an intramedullary rod with one distal screw as compared with a method of tibiotalocalcaneal fixation using three cross-cannulated screws. The results show that an intramedullary rod placed in a retrograde manner stiffens the hindfoot and the placement of interlocking screws enhances that effect (Experiment 1). The intramedullary rod with one distal screw inserted provides more stiffness to the hindfoot than does three cross-cannulated screws (Experiment 2).

Treatment of acquired adult planovalgus deformities with subtalar fusion.

A retrospective review was conducted of isolated subtalar arthrodeses performed on 32 adults (34 fusions) between August 1990 and September 1993. Each fusion was performed using a single large cannulated lag screw through the talar neck. The American Orthopaedic Foot and Ankle Society standard clinical rating system for the ankle and hindfoot was used to assess outcome. Patients answered subjective questions based on the scale. Followup examination was done to evaluate clinically and radiographically each patient's foot and ankle according to the scale. Average patient age was 53 years (range, 27-80 years). Average followup was 30.8 months (range, 16-55 months). Twenty-four patients answered the subjective questions, and the average subjective score was 47 of a maximum 60 points (range, 9-60 points). Clinical data from 17 patients showed an average objective score of 30 of a maximum 34 points (range, 25-34 points). The average total score was 77 of a maximum 94 possible points (range, 34-94 points). Forty-two percent of the patients indicated a 100% improvement, 42% a 75% improvement, and 16% a 50% improvement. Eighty-three percent stated they definitely would have the procedure again. Results indicate that subtalar arthrodesis is an effective treatment for adult patients with pain and disability secondary to acquired planovalgus, posttraumatic, and inflammatory conditions of the hindfoot. In addition, the American Orthopaedic Foot and Ankle Society standard rating system of the ankle and hindfoot corresponds to clinical outcome.

Ultrafiltration using low volume peritoneal dialysis in critically ill infants and children.

Ultrafiltration (UF) using dialysate volumes of less than 20 ml/kg was assessed in 12 critically ill infants and children with hypervolemia as the primary indication for dialysis. Ten of the 12 required mechanical ventilation (O2 requirements 45-100%). Seven, all infants, received at least one pressor intravenously in attempts to maintain systolic blood pressure of 60. Age was 22 +/- 11.5 mos. (mean +/- SE) with weight of 11.1 +/- 4.3 kg (range 2.4-50 kg). Dialysis prescription was as follows: Volume of 10.1 +/- 1.3 ml/kg/exchange; dwell time 30-45 minutes; drain time 15-20 minutes. Glucose concentration ranged from 1.5-4.25%. Drained dialysate volume expressed as a percent of volume instilled was 133.5 +/- 3.4%. When calculated for body weight and time, UF was 3.0 +/- 0.3 ml/kg/hour. UF was not significantly different in patients requiring pressors versus those not requiring blood pressure support. Although minor ventilatory changes were required, significant deterioration of blood gases did not occur during the first 3-6 hours of PD, nor did significant changes in blood pressure develop. Hyperkalemia, present in 1 patient prior to PD, resolved using this regimen. Low volume PD was a viable alternative to hemodialysis or hemofiltration for control of hypervolemia in this small group of very ill infants and children.

Complications of nasogastric and gastrostomy tube feedings in children with end stage renal disease.

Twelve children with end stage renal disease requiring dialysis received enteral feedings via nasogastric (NG) or gastrostomy (G) tube between 1984 and 1989 for provision of adequate nutrition. Records were reviewed for frequency and types of complications seen. Six patients, ages 1 week to 16 months received NG feedings for a total of 32 months. Complications included persistent vomiting with recurrent aspiration (2), persistent vomiting with peritoneal dialysis (PD) exit site leak (1), sinusitis (1), and refusal to continue NG feeds because of patient/parental anxiety (1). Three of the 6 were changed to G tube feedings after 2 days to 3 months. The complication rate was 1 per 6.4 patient months. Nine patients, ages 4 days to 11 years, received G tube feedings for 64 months. The complication rate was similar, 1 per 7.1 months. Complications were PD fluid leak around G tube exit site (1), G tube infection (2), G tube obstruction requiring tube replacement (3), tube migration producing intestinal obstruction (1), and gastrocutaneous fistula (2). Both methods were associated with similar complication rates, although somewhat different types of complications were seen. The young dialysis patient may have certain unique risks in addition to the complications generally associated with enteral feedings.

Fractures of the femoral shaft: a prospective study of closed intramedullary nailing, modified open intramedullary nailing, and cast-bracing.

One hundred twelve consecutive fractures of the femoral diaphysis were treated in a prospective study at Grady Memorial Hospital, a designated trauma center, during the three-year period 1978 through 1980. Fifty of these were treated by closed intramedullary nailing; all united. Of the rest, 20 were treated by modified open intramedullary nailing, and 42 by cast-bracing. Closed intramedullary nailing offered a significant reduction in hospitalization and healing times compared to the other two methods; however, the high cost of equipment, along with the added cost of reoperation to remove the nail, rendered cast-bracing economically superior. Fractures treated by modified open intramedullary nailing developed no infections, but these patients lost significantly more blood during operation than those treated by closed nailing. Because of the decreased hospitalization and healing times, we prefer the closed intramedullary nailing technic for use in selected femoral fractures treated during the acute phase by an experienced surgical team.