Biomedical subjects
Publications and source records attributed to U Jonsson.
In a prospective randomized study of 99 displaced Colles' fractures, regional intravenous block was compared with local anesthesia in the fracture hematoma. Patients treated with regional intravenous block had less pain during the manipulation of the fracture and better grip strength at the 6-month follow-up. The anatomic end result (dorsal angulation) was better after regional anesthesia.
In a prospective randomized study of 47 severely displaced Colles' fractures, 23 had external fixation and 24 had a dorsal plaster cast. Five fractures in the plaster-cast group redislocated and were externally fixed at rereduction after the 11-day follow-up. Three patients in the external-fixation group had a noncomplicated pin-tract infection, and 1 patient had a transient sensory disturbance arising from the cutaneous branch of the superficial radial nerve. After 1 year, the patients allocated to primary external fixation had a better radiographic and functional end result; according to Lidström's grading, 19/22 were excellent or good after external fixation as compared with 12/19 after plaster-cast treatment.
The tendency of 267 consecutive Colles' fractures to dislocate during plaster-cast treatment was correlated with several parameters measured from the initial radiographs. Stepwise logistic regression analysis showed that radial axial shortening had the greatest prognostic power. The age of the patient and Lidström's class provided additional prognostic information. Initial radial axial shortening of 5 mm or more generally indicated an unfavorable anatomic end result.
A series of 68 undisplaced or minimally displaced Colles' fractures was randomized into two groups undergoing treatment with either a plaster cast or an elastic bandage. Pain, function, grip strength, and range of motion were evaluated 1 year later. There was a difference in the functional outcome in favor of the patients treated with an elastic bandage, who did not have more fracture redislocations than those treated with a plaster cast.
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A prospective radiological study was performed on 170 Colles' fractures which were reduced and treated in plaster. Twenty-nine fractures, which displaced and which needed a further reduction and external fixation, were excluded. The mean length of the radius decreased during plaster treatment to the same position as before the initial reduction. Radial angular compression also increased significantly during treatment. Among the seventeen fractures which were malunited, twelve had definitely displaced after the 11th day.
Thirty-nine clinically unstable knees caused by anterior cruciate ligament rupture were evaluated 5-8 years after medial and lateral extraarticular stabilization according to Slocum and Ellison. At the follow-up, 10 knees had been subjected to an intraarticular anterior cruciate ligament reconstruction, and one knee was not available for follow-up. The mean Lysholm score for the 28 reexamined knees was 84 out of a maximum of 100 points. Activity scores were generally low, and all the knees had increased anterior drawer instability. The combination of the pes anserinus and lateral extraarticular repair did not give acceptable long-term results.
The aim of this study was to investigate the predisposing factors, fracture location, treatment, and final outcome of femoral fractures after total hip arthroplasty (THA). From 1975 to 1983, 28 patients were seen with 29 fractures on the same side as the prosthesis. Most of the fractures were caused by minor trauma, and prior hip surgery was the most common predisposing factor. Two patients underwent early operation and six were treated with protected weight bearing. Twenty-one underwent initial skeletal traction, and 14 of these fractures united without further surgery. Six of the patients treated with initial skeletal traction were operated on early, mainly by osteosynthesis, due to poor fracture alignment. Three of these fractures united, but one subsequently required revision arthroplasty because of loosening of the femoral component. Two patients died and three had a permanent pseudarthrosis or a Girdlestone resection. Nineteen of the 21 fractures not operated on united and five of the eight operated united. The results indicate that when good fracture alignment is achieved with traction, union is not jeopardized by either the prosthesis or the cement.
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At independence in 1961, Tanzania inherited a classic economic structure from Britain. The most immediate aims of the new government included replacing the colonial administration with trained nationals, radical change of the development philosophy and strategies and development of self-reliance in all development sectors. The Arusha Declaration of 1967 was the turning point in Tanzania and achievements in all the sectors can be measured against targets established soon after. This paper examines development in the health sector within the wider national framework.
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It has been claimed that the increase in the strength of growing bone is due to increased mineral content. The strength of collagen is based on intermolecular covalent cross-links, and it has also been proposed that cross-link changes increase bone strength. Measurements of the content of calcium, collagen, and water, as well as cross-link analyses, were performed on the tibial cortex of growing dogs. Within the age range studied (8-44 weeks), no changes in calcium content expressed as a percentage of dry bone weight were seen. Collagen content expressed as weight of hydroxyproline per dry bone weight showed a minor reduction during growth. However, water content decreased considerably up to an age of about 25 weeks, which implies a concomitant increase in the amount of bone material. Of the two cross-link main groups, reducible and nonreducible, it is only possible chemically to analyze the reducible. During the final part of the period of growth and mechanical maturation of the bones, the number of reducible cross-links decreases. This indicates a concomitant increase in the more stable nonreducible forms. The possible mechanical relevance of the chemical changes found during growth is discussed.
Thirty patients who required surgery for an unstable knee with "giving way" symptoms were operated during 1979-1981 with a pes anserinus transfer and an Ellison procedure at the same séance. All patients had an insufficient anterior cruciate ligament prior to surgery. Of these 24 patients had a positive pivot-shift test, and 26 patients had an anteromedial rotatory instability. Twenty-eight patients were seen at a follow-up after an average of 28 months (range 19-49). There were 12 women and 16 men, with a mean age of 28 years. Eleven patients (39%) declared that their knee function was distinctly improved, and six (21%) that it was moderately improved after surgery. Knee function was unchanged for ten patients (36%), and one patient said that the knee function had deteriorated after surgery. The functional result was not correlated with the duration of symptoms or with the follow-up time. Physical examination revealed that the anterior drawer had not disappeared for any of the patients. A positive pivot-shift sign was still present in 18 patients, and 23 patients displayed an increased varus instability.--All but six patients still had some instability experiences, and most of them could not completely return to active sports. However, the method could provide an alternative for patients engaged in frequent but not heavy physical activity.
An experimental method using a computerized torsion machine to study the mechanics of entire diaphyseal bones is described. Besides controlling continuous torsion to ultimate fracture of the bone, the computer is able to use non-linearity of the torque-twist curve as a criterion for reversal of the direction of torsion and to control repeated loadings and unloadings with a graduated increase of deformation until final fracture. It permits determination of a small residual deformation, and several other parameters characterizing the load-deformation curve. The linearity of the equipment is shown to be good and precision is high, with a method error of 2.3% when determining stiffness. Repeated loadings and unloadings of entire dog femora revealed a minor residual deformation before ultimate fracture.
Some environmental factors of possible aetiological importance for primary liver carcinoma (PLC) in males were analysed in a case-control study including 83 cases of hepatocellular carcinoma (HCC), 15 cases of intrahepatic cholangiocellular carcinoma (CC), 3 cases of haemangiosarcoma and 1 case of unspecified sarcoma in the liver--102 cases in total. Two matched controls were used in each case. One case with haemangiosarcoma was exposed to polyvinyl chloride. The case with unspecified soft-tissue sarcoma was exposed to phenoxy acids. A 4-fold increase in the risk of HCC was seen in alcoholics, and regular drinking gave a 3-fold increase in the risk. Exposure to organic solvents gave a 2-fold increase in the risk of HCC. No increased risk was observed for cases exposed to various other chemicals. Three cases of HCC had a previous diagnosis of porphyria acuta intermittens (PAI), versus no control. Six cases of HCC had a previous diagnosis of porphyria acuta intermittens (PAI), versus no control. Six cases with PLC had polyphyria cutanea tarda (PCT) which in 4 cases was related to alcoholism and in one case to haemochromatosis.
Entire and fresh pairs of tibiae and femora from dogs have been tested with a computerized torsion machine. No differences were observed within the pair for several structural parameters, ensuring a right-left congruence of the load deformation curves of the tested bones.
Entire diaphyseal bones from adult dogs were repeatedly loaded in torsion. The residual deformation after unloading from the non-linear deformation range was found to decrease with time. Acoustic-emission signals typical for micro-cracking were registered not only during loading in the non-linear deformation range but also during the initial phase of the following unloading. The initial torque and twist required for further micro-cracking decreased for every subsequent load-cycle, i.e. with the amount of cracking already formed. These observations are indications of visco-elastic properties of bone material.
Fresh tibiae and femora from 22 harriers ranging in age from 8 to 44 weeks have been studied with a computerized torsion-machine. The growth of the dogs studied ceased at an age approaching 30 weeks. The strength and stiffness of the entire bones also ceased to increase at that age, and the increase in stress at fracture and shear modulus of the bone material strongly declined in impetus. This means that no important maturation, as measured in strength of the bone material, takes place after cessation of growth. The fracture twist angle per unit bone length was greatest for the younger bones and decreased to an age of around 25 weeks; the relation, however, between the linear and the non-linear part of the torque-twist curves did not change. Furthermore, the study indicates that juvenile bones, like adult bones, are essentially elastic-brittle, and there was no sign of increased plasticity in the young bones.