PubMed Health⌕ Search

Biomedical subjects

K Kolstad

Publications and source records attributed to K Kolstad.

At least 19 recordsLinked to original sources
PubMed2001

All-polyethylene versus metal-backed and stemmed tibial components in cemented total knee arthroplasty. A prospective, randomised RSA study.

We studied the quality of fixation of the tibial component using radiostereometric analysis (RSA) in 40 patients who had undergone a cemented Freeman-Samuelson total knee arthroplasty. They were prospectively randomised to either a stemmed metal-backed (MB) or non-stemmed all-polyethylene (AP) tibial component. The articulating geometry of the implants was identical, as was the operative technique and the postoperative regime. The study showed no complications of fixation using AP tibial components, and the migration was the same as that of their metal-backed counterparts. There was no bony collapse or increased subsidence of any part of the tibial component or increased incidence of radiolucent lines in the knees with AP components. Most AP implants were stable between one and two years after surgery, a finding known to be of positive prognostic significance when predicting future aseptic loosening.

Aged↗
PubMed2000

Low-conforming all-polyethylene tibial component not inferior to metal-backed component in cemented total knee arthroplasty: prospective, randomized radiostereometric analysis study of the AGC total knee prosthesis.

In a prospective, randomized study of 40 patients, the quality of fixation of cemented metal-backed versus all-polyethylene tibial components of the unconstrained anatomic graduated component total knee arthroplasty design was studied during 2 years using radiostereometric analysis (RSA). The shape, as well as the articulating geometry, of the implants was identical, as was the operative technique and the postoperative regimen. In this study, no negative consequences regarding the quality of fixation using an all-polyethylene tibial component with unconstrained articulating surfaces could be identified. In all aspects, the all-polyethylene tibial components displayed migration on par with, or sometimes lower than, their metal-backed counterparts. The rotations of the all-polyethylene components were equally low as for the metal-backed components, and maximum lift-off was significantly lower than for the metal-backed implants. We could not identify any collapse of the bone at the medial condyle or increased subsidence at the medial part of the tibia or increased rates of radiolucent lines in the knees with all-polyethylene components. All all-polyethylene implants seemed to be stable within the resolution of RSA between 1 and 2 years, a finding known to be of positive prognostic significance regarding future aseptic loosening.

Aged↗
PubMed2000

Body composition and development measured repeatedly by computer tomography during growth in two types of turkeys.

Distribution and development of fat, muscles, and bone were studied repeatedly by computer tomography from 4 to 17 wk of age in two commercial strains of turkeys (BUT-9 and Nicholas) of both sexes. Generally, the proportion of total fat and meat increased and bone decreased significantly throughout the experimental period for both strains and sexes. When compared at the same age or body weight, BUT-9 tended to have a higher percentage of meat than did Nicholas (0 to 3 percentage units). From 8 to 17 wk of age, Nicholas showed higher fat percentage and lower bone percentage than BUT-9. Based on this study, regardless of weight at slaughtering, BUT-9 should be preferred. Because males had a significantly higher body weight gain and higher percentage of meat from 8 wk of age, males should be used in production to fit the market for high slaughter weights with large pieces of meat. Because females had a higher meat percentage at young ages compared with males, but showed an earlier fattening and lower weight gain, females should preferably be slaughtered at lower live weights. Computer tomography can be considered an appropriate but expensive method to study body composition and development in turkeys.

Aging↗
PubMed1999

Stability assessment of a moderately conforming all-polyethylene tibial component in total knee arthroplasty: a prospective RSA study with 2 years of follow-up of the Kinemax Plus design.

The magnitude and pattern of the migration of an all-polyethylene tibial component with moderately conforming articular surfaces in total knee arthroplasty was analyzed in 20 patients > or =60 years during a 2-year follow-up using radiostereometry (RSA). Most of the migration occurred during the initial 4 months, whereafter the migration diminished, reaching a mean maximum migration of 0.75 mm at 2 years. Similar patterns were found for rotation of the implant. Maximum subsidence at 2 years was 0.7 mm and was most commonly located at the posteromedial part of the tibial component. These results indicate that an all-polyethylene tibial component with moderately conforming articular geometry and with a thickness of 10-12 mm demonstrated migration patterns compatible with a favorable prognosis in regard to future aseptic loosening.

Aged↗
PubMed1998

Postoperative drainage of knee arthroplasty is not necessary: a randomized study of 90 patients.

We studied the management of postoperative drainage after total knee replacement (TKR). 90 primary total knee joint arthroplasties were prospectively randomized into 3 groups: a) no drain, b) an autotransfusion system, c) a standard disposable closed suction drainage system. We monitored hemoglobin and hematocrit values, drainage volume and transfusions (homologous and autologous), range of knee motion, knee swelling and hospital stay. Parameters were recorded preoperatively, days 0-8 and 4 months postoperatively. No significant differences were seen between the groups in any of the parameters measured. The results show no benefit from using postoperative drainage systems in knee arthroplasties. Savings of SEK 400 (USD 55) per patient would have resulted if drains had not been used at all.

Aged↗
PubMed1997

Thiazide-induced hyponatremia in the postoperative total joint replacement patient.

The thiazide diuretic is a common medication in the elderly population for the treatment of hypertension. These same patients are the largest population for surgical intervention for joint arthroplasty. Postoperative management of these patients has shown to be complicated by hyponatremia associated with the use of thiazide diuretics. This study evaluates a consecutive series of 408 patients undergoing elective joint arthroplasty. An association was found with the use of thiazide diuretics in the preoperative period and the development of postoperative hyponatremia. The study is presented, along with a relevant review of the literature and suggestions for the orthopedic staff to limit the risk of hypoantremia and prolonged hospitalization in an otherwise stable postoperative course.

Adult↗
PubMed1996

Marmor modular knee plateau positioning and prosthesis survival in 55 knees with rheumatoid arthritis.

In a long-term follow-up of 55 Marmor knee arthroplasties in patients with rheumatoid arthritis operated on between 1975 and 1977, the radiologically visible indicator wire was used to identify the position of the tibial components. The survival rate of the prostheses at 15 years was 0.71, and the revisions were evenly distributed over the observation period of 16 years. No significant relationship was found between the slope of the tibial components postoperatively and the survival of the prostheses. However, a postoperative valgus angle of the leg of 3 deg or more tended to increase the risk of revision (RH = 2.7, 95% CL = 0.8-8.9). The patient's sex, affected side or weight did not influence prosthesis survival.

Adult↗
PubMed1996

The Wagner revision stem for severe osteolysis. 31 hips followed for 1.5-5 years.

We used the Wagner (1989) method in 31 hip revisions because of loosening with pronounced scalloping, which made a conventional revision unsuitable. The radiographs showed that within a few months new bone developed in the defects. In 5 cases, a new revision was necessary at an early stage, because of dislocation and/or subsidence. At follow-up after 3 (1.5-5) years, 21 of the remaining 26 hips were pain-free and 23 had almost full range of motion.

Adult↗
PubMed1995

BET3 encodes a novel hydrophilic protein that acts in conjunction with yeast SNAREs.

Here we report the identification of BET3, a new member of a group of interacting genes whose products have been implicated in the targeting and fusion of endoplasmic reticulum (ER) to Golgi transport vesicles with their acceptor compartment. A temperature-sensitive mutant in bet3-1 was isolated in a synthetic lethal screen designed to identify new genes whose products may interact with BET1, a type II integral membrane protein that is required for ER to Golgi transport. At 37 degrees C, bet3-1 fails to transport invertase, alpha-factor, and carboxypeptidase Y from the ER to the Golgi complex. As a consequence, this mutant accumulates dilated ER and small vesicles. The SNARE complex, a docking/fusion complex, fails to form in this mutant. Furthermore, BET3 encodes an essential 22-kDa hydrophilic protein that is conserved in evolution, which is not a component of this complex. These findings support the hypothesis that Bet3p may act before the assembly of the SNARE complex.

Amino Acid Sequence↗
PubMed1995

Inflammatory laboratory tests after joint replacement surgery.

Objective criteria for suspected early postoperative infections after arthroplastic surgery are sparse. In order to establish the usual time course of some inflammatory laboratory values after hip and knee arthroplasty, these values were followed prospectively in nine patients. C-reactive protein in serum was normalised within about two weeks. On discharge 14 days postoperatively the erythrocyte sedimentation rate was still high (mean 64 mm/h), but at follow-up four months after operation it was restored to normal. The total blood leucocyte count remained essentially within normal limits throughout the postoperative period. The morning temperature was slightly raised, to about 38 degrees C in a few patients on the first and second days postoperatively, but was otherwise normal.

Aged↗
PubMed1994

Revision THR after periprosthetic femoral fractures. An analysis of 23 cases.

23 consecutive proximal femoral fractures in 22 patients, who had previously undergone total hip arthroplasty, were treated with long revision stems. At the time of the fracture, 21 stems were loose. An uncemented Wagner revision stem was used in 9 cases and different conventional revision stems in the others. All fractures healed, but 7 of the conventional revision implants rapidly loosened again, whereas so far none of the Wagner stems have loosened.

Adult↗
PubMed1992

Uptilting osteotomy of the lateral tibial plateau for a knee deformity. A case report.

A middle-aged woman had had anterior poliomyelitis at 11 years of age that had left her with residual weakness in both legs. She gradually developed a recurvatum and valgus deformity in both knees, which caused pain and instability. A technique to restore the top of the tibia by means of a rotational osteotomy of the lateral tibial plateau is presented. This operation resulted in painless, asymptomatic knees and improved function.

Female↗
PubMed1991

Localization of tyrosine hydroxylase and olfactory marker protein immunoreactivities in the human and macaque olfactory bulb.

These studies utilized specific antisera to examine the distribution and characteristics of tyrosine hydroxylase and olfactory marker protein in the olfactory bulb of the human and macaque monkey. The macaque displayed immunoreactive profiles to both antisera comparable to those described previously for other mammals. Olfactory marker protein antiserum labeled the olfactory nerve layer and glomeruli. Within the glomeruli, labeled processes were interdigitated with unlabeled processes believed to be the postsynaptic dendrites of olfactory bulb neurons. Tyrosine hydroxylase antisera labeled somata surrounding the glomeruli as well as putative dendritic processes with the glomerular neuropil. It appeared that only a subset of juxtaglomerular neurons were immunoreactive. A similar pattern was observed in the human for both antibodies. Fascicles of olfactory marker protein immunoreactive olfactory nerves often coursed long distances into the olfactory bulb prior to arborizing within a glomerulus. The data suggest that olfactory receptor cell axons destined for specific glomeruli fasciculate into bundles prior to reaching the target glomeruli. The immunoreactivity in the human to tyrosine hydroxylase was qualitatively similar to the macaque and other mammals although the number of labeled somata and intraglomerular processes appeared lower. As in the macaque, it appeared that only a subset of juxtaglomerular neurons were labeled.

Adult↗
PubMed1984

Non-sporeforming anaerobic bacteria in clean surgical wounds--air and skin contamination.

The contamination of clean surgical wounds with anaerobic and aerobic bacteria was studied in 52 hip operations. In addition to wound samples, samples from air and the patients' skin were taken. The median of the total number of bacteria isolated from the wounds was 26 colony-forming units (cfu). The median percentage of anaerobic bacteria in the wound counts was 30. Propionibacterium spp. were found in 71 per cent of the wounds and anaerobic or microaerophilic cocci, most often Peptococcus spp., were found in 23 per cent. In six of 43 patients the same bacterial flora was seen in the skin samples and wounds. The geometric mean of the total number of bacteria in the air was 70.3 cfu/m3. Of these the median percentage of anaerobic bacteria was 30.3. When operating clothing of a disposable fabric (Barrier 450, Johnson & Johnson) was used, the counts of airborne bacteria were a little less than half those found when conventional cotton clothing was worn. Probably because of the overall low air counts in the operating theatre and the great variability in the individual bacterial counts from the operation wounds, a significant decrease in wound contamination was not observed. A positive correlation was found between the duration of operation and wound contamination.

Adult↗