Harrington Method Research Articles

Outcome of surgical treatment by Harrington method different combinations in patients with scoliosis

Authors analysed the outcomes of surgical treatment in 108 patients with scoliosis. Depending on surgical technique the patients were divided into 4 groups. The base of surgical procedures was different combinations of Harrington distractor with Luque rod as well as with segmental angular resection at the deformity apex. The efficacy of segmental angular resection that enabled to mobilize the rigid scoliotic deformity and increase intraoperative correction was detected. The combination of that procedure with the deformity correction by Harrington distractor and lateral traction by Luque rod allowed to achieve more marked correction and to preserve it to a greater degree and for longer time (2 years after operation 67,8% of achieved correction was preserved). It was also shown that fixation of corrective spine by Harrington distractor only did not provide considerable preservation of primary achieved correction in long term postoperative period (2 years after operation 47,3% of the achieved correction was preserved).

Requirement systems

Methods for carrying out transfinitely nested priority constructions have been developed by Harrington [7] and by Ash [2, 1, 3, 4]. Ash's method has different versions, with later ones becoming simpler. Lemmp and Lerman [11] have also developed a method, for finitely nested constructions. Ash formulated abstractly the object of a nested priority construction, and he proved a metatheorem for what he called “α-systems”, listing conditions which guarantee the success of the construction. Harrington's method of “workers”, at least in its original, informal state, seems more flexible than Ash's α-systems.In [10, 9], there are finite and transfinite versions of a metatheorem for workers. The statements are complicated, and these metatheorems have not proved to be very useful. The present paper gives a new transfinite metatheorem. The statement is considerably simpler than the one in [9], although not so simple as that in [3]. The new metatheorem grew, in part, out of an effort to find a new proof of Ash's metatheorem. The new metatheorem yields the one in [3], and it seems more flexible. A different generalization of Ash's metatheorem will be given in [5].Ash's metatheorem is easier to use than the one in the present paper, and the result in [3] is certainly the one to use wherever it applies. Here we give one application of the new metatheorem which does not seem to follow from the result in [3]. This is a theorem on models “representing” a given Scott set, which implies one half of a recent result of Solovay [18], on Turing degrees of models of particular completions of Peano arithmetic (PA).

Lumbar and thoracic spinal fusion with transpedicular fixation (including a novel distraction and compression device). A preliminary report.

Experience with three different systems of transpedicular fixation in fusion of the lumbar and thoracic spine over 4 years is reported. The Roy-Camille plates, Louis plates, and the Balgrist turn-buckle arrangement are compared. The Balgrist device allows both extension and compression, and affords better stability. Far better clinical results were obtained with transpedicular fixation in general than with the Harrington method.

Operative treatment of neuropathic pelvic obliquity

Neuropathic fixed pelvic obliquity remains an important orthopedic problem. The three known methods for operative correction of this deformity are described. The combined VDS and Harrington method is described in this paper, along with its advantages. The combined operation corrects kyphosis, lordosis, and scoliosis and offers immediate stability of the spine with good correction of the fixed pelvic obliquity.

Harrington's elusive balance

Abstract The revival of interest in James Harrington's political theory which has occurred in recent years has not led to a resolution of the puzzle about his Agrarian Law. That puzzle requires unfolding how Harrington expected that the Agrarian would achieve his ambitions for a stable commonwealth. This paper suggests one explanation of the difficulties encountered, by focusing on ambiguities in Harrington's terminology and on inadequacies in his method. While we cannot provide a convincing explanation of how the Agrarian worked, we can understand how Harrington was confused and confusing in his description of it. Harrington's principle of balance purports to show that the distribution of political power in a polity follows that of property. His Agrarian law is designed to maintain the political system of Oceana, his projected common-wealth. To understand the complexities of the Agrarian, we need to examine Harrington's method (I), his views on inheritance (II) and the relative importance of different forms of property (III). The last section relates the problems identified in these three parts to the difficulty of understanding the Agrarian.

Coulomb effect on the proton-proton low-energy scattering parameters

The effect of the Coulomb force on the proton-proton low-energy scattering parameters is examined when the nuclear interaction is represented by a separable potential. Naqvi's two-term potential as well as Yamaguchi's one-term potential are considered, following Harrington's method. After removing the Coulomb effect, the “nuclear” scattering length and effective range are both found to be somewhat larger (in absolute values) than those previously obtained by using hard-core local nuclear potentials.

Interaction of Microwave Radiation with a Polar Gas under Conditions of Power Saturation

The propagation of microwave radiation through a gas-phase dielectric under conditions of power saturation is considered. It is shown that the nonuniform polarization gives rise to additional modes of electromagnetic oscillation. The amplitudes of the induced electric field are estimated and shown to be small. The results of the calculation substantiate that Harrington's method of averaging the power distribution in determining the power density distinction function φwg is correct for application to microwave spectroscopy.

Pulmonary Function in Kyphoscoliosis before and after Correction by the Harrington Instrumentation Method

Studies of pulmonary function were performed on seventy-four patients with thoracic scoliosis prior to corrective surgery by the Harrington method. The angle of the curvature, vital capacity, maximum breathing capacity, and arterial oxygen saturation were recorded at intervals up to five years after surgery. Before operation in the patients with idiopathic scoliosis, there was a significant negative correlation when vital capacity, maximum breathing capacity, and arterial saturation were compared with the angle of the curvature. No such negative correlation was found in the patients with poliomyelitic and with congential scoliosis. One year after operation in the over-all series, there was a decrease in the average vital capacity from 57 to 48 per cent of the predicted capacity and a decrease in the maximum breathing capacity from a preoperative average of 55 to 51 per cent of the predicted value. The patients with congenital scoliosis showed the greatest decrease postoperatively in both vital capacity and maximum breathing capacity; the patients with idiopathic scoliosis showed a small decrease in vital capacity and a slight increase in the maximum breathing capacity; and the patients with poliomyelitic scoliosis showed the same pattern as the combined group. Two years and five years after operation, results were essentially unchanged from those obtained at one year. An over-all decrease in the average vital capacity occurred from the preoperative 56 per cent to 50 per cent at two years. The maximum breathing capacity remained essentially the same—it was 55 per cent of the predicted value before operation and 56 per cent two years after operation. Arterial oxygen saturation increased from 93.5 to 95.2 per cent after operation while there was a decrease in the spinal curvature from the preoperative average of 87 degrees to an average of 53 degrees. There was no correlation between the change in the angle of the curvature and the changes in the vital capacity of maximum breathing capacity except in the patients with poliomyclitic scoliosis. In these patients, a significant correlation was found between the amount of correction of the curvature and the decrease in vital capacity. The Harrington method for the correction of kyphoscoliosis does not improve the average vital capacity or maximum breathing capacity but may improve arterial oxygen saturation. Since there is a positive correlation between the decrease in the spinal curvature and the decrease in vital capacity in the poliomyelitis group, over-enthusiastic correction of the curve may lead to a further decrease in lung volumes, but adequate treatment should be instituted as soon as a curve is noted in order to preserve that lung function is left. Since before operation there was a correlation between the amount of curvature and the decrease invital capacity in the patients with idiopathic scoliosis, treatment of idiophathcic scoliosis should be instituted if there is any sudden increase in the curvature or as early as possible if the curve is slowly progressing. Treatment then will preserve what respiratory function is present at the time of surgery.

ANAESTHESIA FOR THE SURGICAL CORRECTION OF SCOLIOSIS BY THE HARRINGTON METHOD IN CHILDREN.

In cases of severe scoliosis, some degree of respiratory disability may be present. If operative correction of the deformity is proposed, accurate assessment is required preoperatively and careful attention should be given to ventilation during anaesthesia and in the postoperative period. Measurements of ventilation have been taken pre- and post-operatively and an analysis of the results will be the subject of a future publication. Blood loss may be severe during the operation of spinal fusion combined with Harrington rod instrumentation and adequate blood transfusion is essential. Methods to reduce blood loss are discussed. An anaesthetic method is suggested which includes moderate hyperventilation combined with a negative phase in expiration. Local infiltration of the operative site with a vasoconstrictor is recommended. Meticulous attention should be given to the positioning of the patient and undue pressure on the anterior abdominal wall avoided.