We applied an autologous blood predonation protocol using recombinant human erythropoietin in pediatric open-heart surgery. The study included 69 children weighing 8 kg or more. Twice before operation, 8 ml/kg of blood was taken. At each donation, 100 (group 1; n = 20), 200 (group 2; n = 11), or 300 (group 3; n = 13) units/kg of erythropoietin was given subcutaneously. In group 4 (n = 25), 300 units/kg of erythropoietin was given 1 week prior to the first donation, followed by 300 units/kg given at each donation. No harmful events occurred during the donation period. During the donation period, the patients' hematocrit decreased but the hematocrit 1 day after the operation remained at 32.1 +/- 0.6% and was 33.3 +/- 0.6% 2 weeks later. The decrease in hematocrit was minimal in group 4 (39.0 +/- 0.6% before donation to 37.5 +/- 0.5% before operation) compared with that of the other three groups. Among those who completed the protocol, 58 patients (93.5%) were discharged without homologous blood transfusion. We consider our protocol of autologous blood predonation using erythropoietin to be safe and effective for avoiding homologous blood transfusion in pediatric patients. The early infusion of erythropoietin prior to the first donation minimizes the decrease in hematocrit level before operation.

Adolescent↗

PubMedDate not supplied

Direct evidence of the anterior cruciate ligament-hamstring reflex arc in humans.

It has been emphasized that the anterior cruciate ligament plays an important role in the proprioceptive feedback system. The anterior cruciate ligament-hamstring reflex has been revealed in animal experiments, but it has not been established in humans. The purpose of this study was to demonstrate direct evidence of the anterior cruciate ligament-hamstring reflex arc. Nine knees in nine healthy subjects were investigated. The anterior cruciate ligament was stimulated by the use of wire electrodes inserted using an arthroscopic technique. Electromyographic signals from the biceps femoris and the semitendinosus muscles were recorded with surface electrodes. The change in electromyographic activity was analyzed after electrical stimulation in the normal knee condition, and again after intraarticular sensation had been interrupted with a local anesthetic. After electrical stimulation, subjects demonstrated increased electromyographic activity of the hamstring muscles in the normal knee condition. This response indicates the existence of an anterior cruciate ligament-hamstring reflex arc. Conversely, there was no change in activity for the hamstring muscle in the anesthetized knee because the afferent impulse from the neural elements of the anterior cruciate ligament had been removed.

Adult↗

PubMedDate not supplied

Techniques for reducing anterior knee symptoms after anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft.

Seventy-five patients underwent unilateral anterior cruciate ligament reconstruction with an ipsilateral bone-patellar tendon-bone autograft at our institution. The graft was harvested using a two-transverse-incision technique, and patellar and tibial bony defects were repaired with cored bone grafts collected by reaming the femoral socket and the tibial socket or tunnel. We evaluated the incidence of anterior knee pain, donor site tenderness, and sensory disturbance after use of these procedures. We also analyzed the correlation between anterior knee pain and age, sex, bone plug length, range of motion, postoperative stability, patellar tendon shortening, infrapatellar nerve injury, and the size of the patellar defect. Thirteen patients reported anterior knee pain. Donor site tenderness was detected in 10 patients and was located on the inferior pole of the patella, the tibial tubercle, or both. Sensory disturbance was found over the infrapatellar nerve area in 13 patients. Statistical analysis showed that anterior instability (side-to-side difference of >3 mm) and residual patellar bony defect (depth >2 mm) were risk factors for anterior knee pain. The results of our study suggest that cored cancellous bone grafting for complete restoration of the donor site bony defects and the two-transverse-incision technique to preserve the infrapatellar branch of the saphenous nerve contribute to prevention of anterior knee symptoms.

Adolescent↗