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P Waris

Publications and source records attributed to P Waris.

At least 19 recordsLinked to original sources
PubMed1990

Radiographically detectable degenerative changes of the lumbar spine among concrete reinforcement workers and house painters.

In this study of lumbar degeneration and the role of mechanical loading in its development, lateral lumbar radiographs of 216 concrete reinforcement workers and 201 house painters aged 25-54 years were examined. Disc space narrowing occurred at about 10 years and spondylophytes at about 5 years younger age in the former than in the latter group. Risk ratios (RR) were estimated from the regression coefficients of logistic regression models. RR for the univariate effect of occupation on disc space narrowing was 1.8, and adjustment for age, earlier back accidents, height, body mass index and smoking had only a minor effect on this relationship, adjusted RR 1.8. The crude RR for spondylophytes was 1.5, and the adjusted RR 1.6. Earlier back accidents showed a significant univariate relationship with DSN, but in multivariate analysis this variate did not retain its significance. It was concluded that heavy physical work enhances the degenerative process of the lumbar spine. Materials handling and postural loading are proposed to be occupational factors of importance in the development of both disc space narrowing and spondylophytes.

Adult↗
PubMed1989

Radiographically detectable lumbar degenerative changes as risk indicators of back pain. A cross-sectional epidemiologic study of concrete reinforcement workers and house painters.

The association between radiographically detectable degenerative changes in the lumbar spine and back symptoms was studied, along with the possible effect of occupational work load. The subjects were 216 concrete reinforcement workers and 201 house painters. A questionnaire provided information on work history and earlier back accidents, and a standardized interview produced data on back symptoms. The occurrence of disc space narrowing, anterior and posterior spondylophytes, and end-plate sclerosis was recorded separately for each intervertebral space from lateral lumbar radiographs. Moderate to severe degenerative changes were associated with increased risk of sciatic pain but not with the occurrence of lumbago or nonspecific back pain. The different types of degenerative changes provided no further information. In a multivariate logistic regression analysis degenerative changes and earlier back accidents were significant independent predictors of sciatic pain. When these two variates were allowed for, the effect of occupation was not significant.

Adult↗
PubMed1985

Pin-hole changes after external fixation of tubular bone.

K-wire-pin-induced changes in cortical bone were studied in the intact rabbit tibiofibular bone. Using a bilateral external fixator two pairs of pins were applied under compression (10 kp), under distraction (10 kp), and in a neutralization sense. After defined intervals the pin-holes were investigated macroscopically and radiologically. Reactive and resorptive changes were present in 101 of 576 (17.5%) pin-holes, infection in 13 (2.3%) pin-holes. Changes were significantly more frequent in the distal pin-holes. The appearance of the pin-holes was not influenced by the type of external fixation used nor did the occurrence depend on the duration of metal implantation.

Animals↗
PubMed1983

Knee degeneration in concrete reinforcement workers.

The loads on the knees in concrete reinforcement work and maintenance painting were analysed on eight construction work sites. A total of 352 reinforcement workers and 231 painters. Finnish men aged 20-64, were clinically and radiologically examined to determine the condition of the knee joints in active workers. The loads on the knees and the occurrence of minor injuries and accidents were higher in reinforcement work than in painting, but the occurrence of symptoms, clinical signs, and radiological findings was equally common in both groups. Reinforcement work seemed to provoke more symptoms from degenerated knees than painting.

Adult↗
PubMed1981

Radiographic evaluation of fracture healing after rigid plate fixation: experiments in the rabbit.

Experimental osteotomies were made in 35 rabbit tibiofibular bones and fixed with rigid stainless steel osteosynthesis plates (DCP/ASIF). The radiographic and histopathologic appearances in the healing osteotomies and adjacent bone were analysed at intervals from 3 up to 24 weeks postoperatively. Radiologically the osteotomy had closed at 9 weeks and microscopically this could be confirmed as longitudinal orientation of the cutter heads across the osteotomy gap with longitudinal orientation of the bone structure. The healing of the osteotomy was accompanied by gross structural changes in the adjacent cortical bone with loss of intracortical and subendosteal osteons, cementing lines and intermediate tissue between the osteons. This was characterized by decreasing attenuation of the cortical bone after healing of the osteotomy and should clinically be regarded as an indication for removal of the implant.

Animals↗
PubMed1981

Torsional strength of cortical and cancellous bone grafts after rigid plate fixation.

Mechanical properties of cortical and cancellous interposition grafts in rabbit tibiofibular bones fixed with 6-hole DCP/ASIF plates were tested with torsional loading after intervals of 3 to 52 weeks postoperatively. In the cortical grafts maximum torque moment at fracture, energy absorption capacity and rigidity increased from 3 to 12 weeks, while the cancellous grafts were more plastic with lower rigidity, higher angular deformation and higher energy absorption. From 12 to 52 weeks maximum torque moment at fracture, energy absorption, rigidity and angular deformation decreased in grafts of both types, the respective means at 36 weeks being 39, 34, 57 and 82 per cent of the cortical grafts, and 26, 17, 42 and 58 per cent of the control values for the cancellous grafts. The differences between the torsional properties of the two graft types decreased with time.

Animals↗
PubMed1981

Biochemical changes in bone grafts stabilized with rigid plates. I. Cancellous grafts.

The effect of rigid plate fixation on the chemical composition of cancellous interposition grafts was studied in rabbit-fibular bones. The concentrations of hexosamines and, to a lesser degree, of hydroxyproline and nitrogen, were high in the graft for the first 6 weeks, decreased from weeks 6 to 12, but remained higher than the corresponding values for the controls throughout the experiment (52 weeks). The ratio of hexosamines to hydroxyproline was highest for the graft at 3 weeks, indicating formation of cartilage and osteoid. The initially low calcium concentration of the graft increased by 35 per cent from weeks 1 to 6, decreased from weeks 6 to 12, and remained below normal thereafter in comparison with corresponding values for the cortical host bone. The ratio of calcium to hydroxyproline increased throughout the experiment, reflecting maturation of the graft to lamellar bone. Thus, biochemically the early incorporation of rigidly fixed cancellous interposition grafts resembles the healing of unimmobilized fractures by callus formation.

Animals↗
PubMed1981

Biochemical changes in bone grafts stabilized with rigid plates. II. Cortical grafts.

The effect of rigid plate fixation on the chemical composition of cortical interposition grafts were studied in rabbit tibio-fibular bones. The concentration of hexosamines increased both in the graft and in the host bone during the first 6 weeks, but thereafter decreased. The concentrations of hydroxyproline and nitrogen increased throughout the experiment. The ratio of hexosamines to hydroxyproline increased in the graft for the first 6 weeks, indicating formation of immature osteoid and bone during this period, but thereafter decreased. The calcium concentration of the graft decreased significantly during the first 12 weeks and remained below normal (-10 to -19 per cent). The mineralization of the graft, assessed by the ratio of calcium to hydroxyproline, decreased continually. The results suggest that cortical bone grafts stabilized with rigid plates heal with only slight chemical signs of callus formation. The demineralization of the graft reflects the porotic changes that take place under the plate.

Animals↗
PubMed1980

Radiographic healing and remodelling of cortical and cancellous bone grafts after rigid plate fixation. Experiments in the rabbit.

Cortical and cancellous interposition grafts, with rigid plate fixation, in the tibiofibular bones of 130 rabbits were followed radiographically for one year. The cancellous grafts healed earlier, but by 12 weeks both graft types had been incorporated, the distal host--graft interface being the last to heal. Progressive cancellous transformation in both the graft and host bone led to an increased over-all bone diameter, a widened medullary canal and a thinned porotic wall.

Animals↗
PubMed1979

Fractures of the proximal femur in Finland in 1975.

Hospital admissions due to fractures of the proximal femur in Finland increased 50% between 1968 and 1976. In this study the established differences and results of treatment in regional and district hospitals are reviewed. From the mortality incidence and the length of hospitalisation, the results were better in regional than in district hospitals, and better for operatively than for conservatively treated patients. Of the different operative methods, the best primary results were obtained with endoprosthetic replacement and osteosynthesis with a fixed-angle nail plate.

Adult↗