Although many investigators have electrically stimulated osteogenesis in vivo, this phenomenon has not been reported in vitro. In this work direct and pulsating currents were applied to in vitro fetal rat tibiae. The results indicated that electric current did cause osteogenesis in vitro, precipitates of calcium compounds formed in the cathode region, and direct current was more effective in stimulating bone growth than pulsed current delivering the same total charge (coulombs).

Animals↗

PubMedDate not supplied

Fibrous dysplasia associated with sickle-cell disease. Report of a case with a discussion of the multiple factors affecting both conditions.

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Adult↗

PubMedDate not supplied

Detection of synovial pseudarthrosis by 99mTc scintigraphy: application to treatment of traumatic nonunion with constant direct current.

A prospective study utilizing technetium scintigraphy to evaluate nonunion patients prior to the electrical stimulation of osteogenesis is reported. Roentgenographic evaluation and scintigraphy must include four views (anteroposterior, lateral and both obliques). Although all nonunion technetium scans showed increased uptake of the radionuclide at the fracture site, three bone scan patterns were identified: (1) intense, uniformly increased uptake at the nonunion site (69.5%); (2) photon deficient (cold) cleft between two intense areas of uptake (23.4%); and (3) indeterminate pattern (7.1%). The presence of a cold cleft between two intense areas of uptake on scintigraphy correlated closely with the presence of a synovial pseudarthrosis at surgery. Nonunions of the humerus were most frequently associated with synovial pseudarthrosis (57.1%). The presence of a synovial pseudarthrosis as suggested by technetium scintigraphy mandates open excision of the lining membrane at the time of electrode insertion.

Diphosphonates↗

PubMedDate not supplied

The electrical treatment of scaphoid nonunion.

Seventy-one percent (12 out of 17) of the previously treated nonunions united within 12 weeks by a semi-invasive technique of electrical stimulation. The electrodes are stainless steel and Teflon-coated except for the 1 cm bare tip. The power source is a 7.5 volt battery in circuit with resistors and transistors such that a constant continuous current of 20 muamp is applied to each electrode. Three or four cathodes are implanted percutaneously, using local or regional anesthesia with radiographic control, usually an image intensifier. A long-arm cast is used for three weeks and then reduced to a short-arm cast which is used for nine additional weeks. The indication for this technique is failure of previous bone grafting. The contraindications are wrist arthritis and an avascular proximal pole. Patient acceptance of this electrode technique was high and morbidity was less than in those patients treated by iliac bone grafting. The treatment of nonunion of the scaphoid by this semi-invasive electrical stimulation technique is a reasonable alternative to bone grafting and provides a salvage procedure when bone grafting or other therapeutic modalities have failed.

Adolescent↗

PubMedDate not supplied

Electrically induced osteogenesis: relationship between charge, current density, and the amount of bone formed: introduction of a new cathode concept.

A study was performed exploring the relationship between charge, current density, and the amount of new bone formed in the medullary canal of the intact rabbit tibia. The results indicate that the amount of bone formed in the vicinity of a cathode is directly related to both current density and charge. Utilizing stainless steel cathodes delivering a constant current of 20 muamps, the optimum current density was found to be 1.06 X 10(3) muamps/mm2 and the optimum charge, 36.29 coulombs. The amount of bone formed with pulsed current approached that formed with constant current only as the total charge delivered by the pulsed current approached that delivered by the constant current. Based on these findings, a new cathode is designed with eight active ports evenly distributed along its length and providing two and one-half times the amount of bone formed by a conventional cathode. This cathode is now in the early stages of clinical evaluation in patients with acquired nonunion.

Animals↗

PubMedDate not supplied

Fracture healing in the presence of anemia.

In experimental fractures in rabbits, a decrease in blood volume associated with anemia delays healing, but uncomplicated normovolemic anemia has no adverse effect. For the purpose of stimulating the repair process in normovolemic anemia individuals blood transfusions would be ineffectual.

Anemia, Hemolytic↗