Bioreconstructive joint scaffold implant arthroplasty in metacarpophalangeal joints: short-term results of a new treatment concept in rheumatoid arthritis patients.

Swanson silicone implant is the "gold standard" of metacarpophalangeal joint reconstruction in rheumatoid arthritis (RA) patients. However, durability problems of silicone implants have led us to develop a new technique based on bioreconstructive implants. PLA96 (poly-L,D-lactide copolymer, L:D ratio of 96:4) scaffolds were engineered. Bioabsorption and substitution of porous PLA96 scaffold with living tissue eventually produce a neojoint. In the current prospective study, 23 RA patients (80 joints) were operated on, using PLA96 implants. Fifteen patients (54 joints) have been monitored for at least 1 year. Pain alleviation was well achieved. Range of motion improvement was emphasized to extension direction of functional arc. The average ulnar deviation was preoperatively 26 degrees, and at follow-up it was 6 degrees. Volar subluxation was noticeable in 56% of joints preoperatively and in 6% at 1-year follow-up. This is the first report of the formation of a living, functional joint in situ by means of a synthetic bioreconstructive joint scaffold. Results of this preliminary short-term study are comparable with previously published data on silicone arthroplasty. However, bioreconstructive prostheses can aid in preventing problems that occur with biostable prostheses. Tissue engineering has created a new era in the reconstruction of damaged joints.

Survivorship of the Charnley total hip arthroplasty in juvenile chronic arthritis. A follow-up of 186 cases for 22 years.

Between 1971 and 1991 we performed Charnley low-friction arthroplasty (LFA) on 116 patients (186 hips) with juvenile chronic arthritis (JCA). We have now carried out a survival study, taking endpoints as revision, death or the end of the year 1993. Overall survival was 91.9% at ten years and 83.0% at 15 years. That of the femoral component was 95.6% at ten years and 91.9% at 15 years and of the acetabulum 95.0% and 87.8%, respectively. Only the use of steroids significantly impaired the survival. We therefore recommend the use of Charnley LFA for young patients with JCA requiring total hip replacement.

HLA B27: a prognostic factor in juvenile chronic arthritis.

This study was performed to assess the frequency of HLA B27 in patients with juvenile chronic arthritis (JCA) of varying severity and outcome by studying three patient categories: those in whom cytostatic treatment with azathioprine had been started, those with secondary amyloidosis, and those with arthroplasty of the knee or hip joints. In the first category the frequency of the HLA B27 allele was compared between those who had attained remission and those who had not. In the second and third categories the rate at which amyloidosis developed and the timing for the need of arthroplasty, were compared for HLA B27-positive and -negative patients. A control group consisted of 37 patients with uncomplicated seronegative polyarthritis. Ten of the 37 patients in the control group (27%) were HLA B27 positive as opposed to 84 out of 190 (44%) in the three study groups. Of the 101 patients treated with azathioprine, two out of 15 in remission were HLA B27 positive, whereas as many as 41 out of 86 with still active disease were HLA B27 positive (p = 0.013). Of the secondary amyloidosis patients, 29 out of 51 carried HLA B27. The HLA B27-positive patients contracted amyloidosis on average 5.9 (median 6.7) years earlier than the HLA B27-negative patients (p = 0.038). Of the arthroplasty patients, 39 out of 91 carried HLA B27. The HLA B27-positive patients underwent arthroplasty on average 2.9 (median 3.5) years earlier than the HLA B27-negative patients (p = 0.050). We conclude that HLA B27-positive cases are accumulated among the most severe cases of JCA.

The control of radon progeny by air treatment devices.

The effect of air treatment devices on the behaviour of radon decay products has been studied in laboratory conditions. An HEPA filter and an electrostatic precipitator were used. Both of the filters were found to decrease the equilibrium factor of daughters and increase the unattached fraction of decay products. In a clean air they also decreased the activity of unattached daughters. The effect of the devices on the health risk caused by radon progeny was estimated by dosimetric calculations. The results corresponding to different models show considerable discrepancy, mainly due to different assumptions about the influence of unattached decay products on the dose.

The influence of an electrostatic precipitator and a mechanical filter on Rn decay products.

In the present work the effect of an HEPA filter and an electrostatic precipitator on the behaviour of Rn decay products has been studied in laboratory conditions. Both filters were found to decrease the equilibrium factor of progeny and increase the unattached fraction of decay products. In a clean air they also decreased the activity of unattached progeny. An electrostatic precipitator was found to produce condensation nuclei which were observable when no other particle sources were present. The ozone produced by the corona discharge of the filter probably has a great effect on the production of these submicron particles. The impurities of the air were found to grow the particles and thus their influence on the behaviour of Rn decay products became in some cases significant.

Three cancellous bone screws versus a screw-angle plate in the treatment of Garden I and II fractures of the femoral neck.

A consecutive clinical series of 33 patients with either an undisplaced (Garden I) or minimally displaced (Garden II) femoral neck fracture was randomly divided into two operative protocols. Half of the fractures were treated with three cannulated cancellous bone screws, while the other half were treated with a standard screw-angle plate device. After a mean follow-up of 2 years, 4 patients had died, while 20 of the remaining 29 hips showed excellent or good, 3 fair and 6 poor functional results. The three-screw fixation seemed to yield more technical complications as compared to the screw-angle plate fixation. However, the differences in functional end-results were of no clear statistical significance. We conclude that the screw-angle plate device gives acceptable results in this group of fractures. The use of cannulated hip screws may be more advantageous in the treatment of dislocated femoral neck fractures, where the torsional strength of fracture fixation and femoral head viability are more critical.

[Behavior of radon in rooms and its use as indicator for ventilation measurements]. / Uber das Verhalten des Radons in Räumen und seine Anwendung als Spurengas bei Ventilationsmessungen.

Investigations have been made to determine the relationship between indoor radon concentrations and ventilation rates and to find the sources for radon in different rooms. The results show that the radon concentration can be estimated by a simple mathematic model in the case of periodical ventilation. The results of measurements carried out in office rooms demonstrate that soil is the main source for indoor radon. The possibility to use radon for the determination of ventilation rates is discussed.

Aerosol penetration through filtering facepieces and respirator cartridges.

Air-purifying respirators must be certified following the National Institute for Occupational Safety and Health (NIOSH) filter test criteria (30 CFR 11). The criteria specify a range for the mean particle size and the measure of spread permissible for the test aerosol. The authors' experiments have shown that aerosol penetration as a function of particle size differs considerably among certified respirators of the same type. Filtering facepieces (disposable respirators) and cartridges of the dust-mist, dust-mist-fume, and high-efficiency particulate air type were tested. The respirators were sealed to mannequins in a test chamber. The aerosol concentrations inside and outside the respirator were measured by an aerodynamic particle sizer and a laser aerosol spectrometer over a particle size range of 0.1 to 15 microns. Five flow rates ranging from 5 to 100 L/min were used to study flow dependency. The aerosol penetration through the filters is presented as a function of particle size. Aerosol penetration and pressure drop are combined to express the performance of each filter in terms of "quality factor." Under the same test conditions, the quality factor of one respirator may be as much as 6.6 times more than that of another respirator of the same type. The filter quality factor has a greater aerosol size dependency as airflow and aerosol size increase. In general, cartridges have a larger surface area than filtering facepieces but not necessarily lower filter penetration or higher filter quality.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on the effects of ionization on bacterial aerosols in a burns and plastic surgery unit.

The effect of the ionization of the air on the decay of bacterial aerosols was studied in a Burns and Plastic Surgery Unit. Ions were generated by free corona needles. The air content of bacteria measured by settle plates was found to be smaller during the ionization period than during the controls period. The number of individual phage typed Staph. aureus strains was especially found to be lower during ionization. The opposite potential increased the disappearance of bacteria from the air. The size of skin particles carrying bacteria is not optimum, but the results obtained show that the ionization may have applications in controlling airborne infection.

Incidence of hip involvement and need for total hip replacement in rheumatoid arthritis. An eight-year follow-up study.

In an 8-year follow-up of a prospective study of recent arthritis, 103 patients were found to have erosive and 97% seropositive rheumatoid arthritis. A 20% incidence of hip joint involvement was observed among them. Moderate radiological changes could be seen in 10%, severe destruction (Larsen 4 or 5) in 3%, and acetabular protrusion in 1% of the patients. It was estimated that the minimum annual need of total hip replacement in rheumatoid arthritis in Finland would be 470. This is about 100 per million in the overall population. At the end of the follow-up the Larsen X-ray index was highly significantly (p less than 0.001), ESR significantly (p less than 0.005), and CRP clearly (p less than 0.03) higher in the 13 patients with radiologically confirmed hip changes than in the 90 without them. Thus their hip destruction is attributable to a more severe disease condition and not to the glucocorticoids administered. Furthermore, HLA-B27 was positive in 69% of the above-mentioned 13 patients compared with 27% of the rest, and this difference (p less than 0.005) may also explain the poor prognosis for true rheumatoid arthritis patients.

Loading and filtration characteristics of filtering facepieces.

Most filtering facepieces used today are made of electret material (material with significant electrical charges on the filter fibers). Because of the addition of this electrical removal force, the filtration efficiency can be significantly increased without increasing the air pressure drop inside the respirator; pressure drop is closely related to physiological load. However, the removal by electrical forces is reduced in time, as aerosols deposit on the filter fibers. We have studied the contribution of this electrical removal and its change in time as a function of aerosol loading. To prove the change in aerosol penetration is due to the reduction of electrical force, the electrical charges were removed from new facepieces by the application of appropriate chemicals. The dust-mist filtering facepieces tested have similar fiber diameters and packing densities, as determined by scanning electron microscopy and pressure drop data. At a face velocity of 10 cm/s (corresponding to 100 L/min through a complete filtering facepiece) and an aerosol size of 0.16 microns, electrical force removal accounts for 69% of the total filtration for the respirator found to have the best filter quality but only 25% for the respirator (from a different manufacturer) found to have the worst filter quality. Our experimental data show that the removal efficiency of these facepieces is reduced in time by as much as this amount. However, under normal wear conditions, the total aerosol particle load is not as high as shown and the filtering facepieces are likely to be discarded before the fiber charges (i.e., the electrostatic attractions) are significantly diminished.

Effect of air ionization on heart rate and perceived exertion during a bicycle exercise test. A double-blind cross-over study.

The influence of ionization of air on heart rate (HR) and ratings of perceived exertion (RPE) during bicycle exercise was studied in nine healthy medical students selected according to a randomized schedule from the class of 90 students. The exercise tests were performed both under negative and positive ionization. The study was made with a double-blind, cross-over design. The body surface exposed to ionic current was made large by reducing the clothing of the subject. A significant overall tendency to lower HR and RPE values under negative ionization was observed (p less than 0.01, sign tests). The RPE values were significantly lower (p less than 0.01, paired t-test and the Wilcoxon test) under negative than under positive ionization at the maximal work load level but not at other relative load levels. However, when separately tested at each relative load level HR values did not differ significantly in negative and positive ionization. The results of this pilot study indicate that ionic composition of the air can modify the RPE and possibly also HR during exercise; negative air ionization seems to be beneficial compared with positive ionization. The mechanisms involved are obscure, but we suggest that negative ionization of air may increase oxidative metabolism through generation of a superoxide radical (O2-) that is reduced to H2O2 by superoxide dismutases.

Atrophy of the thumb web space in rheumatoid arthritis: clinical and electrodiagnostic studies.

One hundred and twenty definite or classical rheumatoid arthritis (RA) patients with an average duration of the disease of 12.1 years were studied. Sixty-two patients had distinct atrophy of the first dorsal interosseous of the hand without definite signs of carpal, cubital, or ulnar tunnel syndrome (group A); 43 patients showed neither distinct atrophy nor sensory disturbance of either hand (group B). Other patients had sensory and/or motor disturbances due to carpal, cubital, or ulnar tunnel syndrome and other neuropathies. Electrodiagnostic examinations revealed that there were differences in the distal latency to the first dorsal interosseous muscle from the wrist between 24 group-A patients and 14 normal controls (P less than 0.05), and between the group-A patients and 12 group-B patients (P less than 0.1). The results of this study indicate that some RA patients with atrophy of the thumb web space may have compression neuropathy of the most distal branches of the ulnar nerve.

Arthrodesis of the first metatarsophalangeal joint in rheumatoid arthritis. Biodegradable rods and Kirschner-wires in 39 cases.

The first metatarsophalangeal joint was arthrodesed in 39 patients with rheumatoid arthritis. Fixation material was either biodegradable self-reinforced poly-L-lactide rods or Kirschner-wires. There were 3 clinical nonunions in the biodegradable group, and none in the K-wire group, and radiographic nonunion in 5 and 2 cases, respectively. The fixator had to be removed in 3 cases in the K-wire group. The biodegradable rods did not seem to be any better than K-wires.

Charnley total hip arthroplasty in ankylosing spondylitis: survivorship analysis of 76 patients followed for 8-28 years.

76 consecutive Charnley low friction hip arthroplasties were performed in 54 (37 men) patients with ankylosing spondylitis from 1971 to 1991 in the Rheumatism Foundation Hospital. Their mean age was 40 (16-67) years. They were followed until the end of 1999. The overall prosthesis survival was 80% at 10 years, 66% at 15 years and 62% at 20 years. The survival of the acetabular component was 91%, 77% and 73% at 10, 15 and 20 years and that of the femoral component 82%, 79% and 77%, respectively. We found no significant risk factor that predicted prosthesis survival.

Charnley low-friction arthroplasty in rheumatoid patients: a survival study up to 20 years.

The survivorship of 1,553 consecutive Charnley low-friction arthroplasties (LFA) in 1,086 patients with rheumatoid arthritis (RA) were analyzed. There were 846 women (1,236 hips) and 240 men (317 hips), with a mean age of 53.1 years (range, 24-77 years; standard deviation, 10.7). A uniform postoperative regimen with protected weight bearing for 2 months (6 months in patients with bone grafting on the acetabular side) was used throughout the whole study. The overall survival with revision as the endpoint was 90.5% (95% confidence interval [CI], 88.7-92.2) at 10 years and 83% (95% CI, 80.3-85.7) at 15 years. The survival of the femoral component was 93.2% (95% CI, 91.8-96.7) and 89.9% (95% CI, 88.0-93.0) at 10 and 15 years, and survival of the acetabulum was 93.6% (95% CI, 92.1-95.1) and 87.1% (95% CI, 84.6-89.5) at 10 and 15 years. The indication for revision was late deep infection in 19 patients (1.2%) and in others aseptic loosening of prosthetic components. Young age, male sex, and secondary reactive amyloidosis impaired significantly the survival of LFA in the RA patients. In all, cemented LFA provided good results, and it can be justified for the treatment of hip destruction in RA.

Measurement of the change in aerosol size distribution with bacterial growth in a pilot scale fermentor.

A number of industrial processes require the addition of materials to the fermentation broth that are hazardous to health and environment. Agitation of broths inoculated with microorganisms can potentially release aerosols large enough to carry the microorganisms. The influence of agitation, air flow, and bacterial growth on aerosol size distribution, air flow, and bacterial growth on aerosol size distribution was investigated in an industrial pilot scale fermentor. A decrease in particle concentration was observed with increase in bacterial growth; this change was more pronounced in the size range above 2 microm. The aerosol size distribution was found to be practically independent of air flow rate and agitation rate for sizes less than 2 microm. However, for particles larger than 2 microm, the concentration was found to increase with an increase in air flow rate and agitation rate.

Hip involvement in seropositive rheumatoid arthritis. Survivorship analysis with a 15-year follow-up.

In a prospective survey of recent arthritis 96 patients had erosive and seropositive rheumatoid arthritis (RA). Severe radiological changes in the hipjoint (Larsen grade 3-5) were observed in 31 (32%) and acetabular protrusion in five (5%) patients 15 years after the onset of arthritis. At the end of follow-up Larsen score 0-100 of peripheral joints (p < 0.015), HAQ (p < 0.001), ESR (p < 0.001), and CRP (p < 0.01) were significantly higher in patients with hip joint destruction than in those without. Secondary amyloidosis was found in eight patients with and in three patients without hip involvement (p = 0.002). In survivorship analysis (the Larsen 0-2 grade hips) an overall predicted rate of survival was 80% after 14 years of rheumatoid arthritis. When analyzed according to HLA-B27 the rate of radiological survival for the patients with a positive test was 62% and 87% for the others (p = 0.02). In conclusion, RA patients with high number of destructive peripheral joints (Larsen score) and high ESR or CRP should be carefully monitored due to the increased risk of hip destruction.