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Biomedical subjects

P Slätis

Publications and source records attributed to P Slätis.

At least 19 recordsLinked to original sources
PubMed1992

Calcitonin treatment in lumbar spinal stenosis: a randomized, placebo-controlled, double-blind, cross-over study with one-year follow-up.

A randomized, placebo-controlled, double-blind, crossover study in 40 lumbar spinal stenosis patients with a 1-year follow-up showed that calcitonin had beneficial effects on the patients' symptoms without producing any notable side effects. Calcitonin had a clear analgesic effect. The mean of walking distance increased, but the crossover trend was not as good as the analgesic effect. Side effects such as erythema and nausea were usually mild and transient. Calcitonin therapy can be used as a conservative treatment in selected cases of lumbar spinal stenosis. When rest pain was mild or the walking distance was under 200-300 m because of neurogenic claudication, the effect of calcitonin seemed to be poor.

Adult↗
PubMed1992

Porous-coated anatomic (PCA) knee arthroplasty. 3-year results.

During 1984-1986, the authors used the PCA total knee replacement system on 92 knees in 86 patients who were followed for an average of 3.2 years (range, 2.2-4.5 years). Of the 92 knees, 42 were treated due to rheumatoid arthritis (RA) and 50 due to primary or secondary osteoarthrosis (OA). The average age of the patients was 60 years (range, 32-78 years). Seventy-one of the 92 prostheses were inserted without the use of methyl methacrylate cement. Fixation screws for the tibial plate were used in eight cases. One knee was revised due to ligamentous laxity by inserting a thicker tibia plate. Radiographically, there was radiolucency of more than 2 mm below two tibial plates (both RA), and four patellar components (2 RA, 2 OA; 4.3% of total) showed a radiolucent zone of 1 mm or more. Clinically, there were no evident loosenings. According to the Weinfeld scale, 80 knees (37 RA, 43 OA; P = NS) had an excellent result, 10 (6 OA, 4 RA) good, and 2 (1 OA, 1 RA) satisfactory. In comparison, the Hungerford scale gave 47 excellent, 30 good, 14 satisfactory, and 1 poor result. These results reflect that cementless PCA total knee replacement also appears to provide good fixation in both OA and RA knees.

Adult↗
PubMed1979

Fractures of the calcaneum.

Sixty-seven patients with 86 fractures of the calcaneum were re-examined 2 to 6 years after their injury. These fractures of the calcaneum were of two types: thalamic, involving the posterior subtalar joint (85%); and nonthalamic, confined to the extra-articular area (15%). Treatment had been by functional therapy, plaster fixation, pin reduction, or open reduction. At followup, only 28 of the 86 heels were entirely painless. Pain was most common posterolaterally along the peroneal tendons; reduction of the tuber (Böhler) angle correlated significantly (p less than 0.001) with an abutment of the peroneal tendons. Motion in the subtalar joint was restricted in two thirds of the series, and in the talocrural joint in one third; a reduction of the tuber angle correlated significantly (p less than 0.001) with reduced mobility of these joints. The duration of sick leave was significantly (p less than 0.05) shorter after functional treatment of displaced thalamic fractures than after treatment with pin reduction and immobilization in plaster. Results were the same with both modes of treatment. The results of treatment of nonthalamic fractures were rewarding, whereas a common consequence of thalamic fractures was considerable impairment of ankle function. The significant correlation between a depressed tuber angle and unsatisfactory functional results suggests that closer attention should be paid to the accurate alignment of the posterior subtalar joint in the treatment of thalamic fractures of the calcaneum.

Adolescent↗
PubMed1979

The healing of experimental fractures by compression osteosynthesis. I. Torsional strength.

Biomechanical properties of osteotomized rabbit tibio-fibular bones fixed with 6-hole stainless steel AO/DCP plates were investigated with torsional loading 3 to 24 weeks postoperatively. During the first 9 weeks maximum torque capacity, energy absorption and torsional rigidity increased, reflecting progressive bony union between the fractured bone ends. From 9 to 24 weeks the values of torque capacity and energy absorption decreased, whereas torsional rigidity seemed to reach a steady state without further significant changes. For the three parameters considered, the mean percentage differences between the osteotomized plated bones and their paired-sham-operated controls were 69, 64 and 80 per cent, respectively. The results suggest that internal fixation of fractured bones provides conditions for undisturbed fracture healing, but that subsequently the rigid nature of the implant has an adverse effect on the cortical bone, which slowly loses strength. Thus the optimal time for removal of the plate seems to be shortly after the fracture has healed and before the bony tissue had been weakened by secondary changes, such as cancellous transformation and spatial rearrangement of the tubular bone.

Animals↗
PubMed1979

The healing of experimental fractures by compression osteosynthesis. II. Morphometric and chemical analysis.

The effects of rigid plate fixation on the structure and chemical composition of bones during healing of experimental fractures were studied by morphometric and chemical analysis at intervals of 3 to 24 weeks after attachment of six-hole AO plates to osteotomized rabbit tibiae. After fracture union gradual porotic transformation could be observed from 9 weeks onwards, with rapid excavation and breakdown of the cortical wall. During the study over 24 weeks the degree of porosity increased from 9.0 +/- 4.8 per cent to 37.5 +/- 10.2 per cent (P less than 0.001). This osteoporosis was accompanied by formation of new subperiosteal bone. The changes in the tubular bone led to a progressive increase in overall diameter and in the area occupied by the medullary cavity throughout the experiment. In the osteotomy area increased values were found for the content of hexosamines and the ratio of hexosamines to hydroxyproline at 3 weeks, indicating formation of connective tissue in the fracture area. Later on, no chemical signs of callus formation could be detected. In spite of the slight increase in the content by hydroxyproline, reflecting the formation of new bone subperiosteally, the chemical composition of the unresorbed cortical bone remained unchanged.

Animals↗
PubMed1979

Medial dislocation of the tendon of the long head of the biceps brachii.

Medial displacement of the long tendon of the biceps brachii muscle is a rare condition associated with degenerative or traumatic ruptures of the rotator cuff. This condition was recorded in nine shoulders during 45 reconstructive procedures on the rotator cuff. Five of the displacements were complete, leaving the tendon medially displaced in a fascial sling; four were incomplete, allowing a to-and-fro medial displacement of the tendon out of the intertubercular groove. Anatomical dissections on eight shoulders showed that the coracohumeral ligament is the key ligament which keeps the biceps tendon aligned in the sulcus: transection of the medial part of the ligament allows the tendon to be medially displaced. There was no pathognomonic clinical sign of the luxation or subluxation. Since abnormal movement of the tendon in the sulcus may be an important cause of shoulder pain, the condition should be carefully looked for during reconstructive procedures on the rotator cuff. Tenodesis of the displaced tendon is recommended, either as the sole procedure or in combination with other reconstructive measures.

Adult↗
PubMed1978

External fixation of double vertical pelvic fractures with a trapezoid compression frame.

Seventeen patients with double vertical fractures of the pelvic girdle were treated by early reduction and subsequent fixation of the pelvic ring with a trapezoid frame. This provided firm fixation of the fractured pelvis. With the frame attached, patients without associated injuries were allowed out of bed within 3 weeks and in every case the frame was removed 6 weeks after its application. External fixation of the pelvic fracture afforded relief from pain and greatly facilitated nursing. At follow-up, all the fractures had united in the position secured initially by the frame and no patient complained of pain in the sacro-iliac joints.

Adolescent↗
PubMed1978

Radiographic abnormalities in tubular bone after rigid plate fixation in rabbits.

Rigid stainless steel osteosynthesis plates (DCP/ASIF) were attached bilaterally onto the intact tibio-fibular bone in 40 rabbits. Axial compression was used on the right side, neutral plate fixation on the left. The radiographic appearances of the bone were analysed 1 day, and 1, 3, 12, 24 and 36 weeks postoperatively. The changes in the bone were progressive, related to the time of fixation, and similar in the right and left leg. The main alterations were a progressive thinning of the cortical bone under the plate and a progressive cancellous transformation of the tubular bone.

Animals↗
PubMed1978

Changes in calcium and hydroxyproline content of cortical bone after compression and neutral plate fixation.

Calcium and hydroxyproline content of intact rabbit tibio-fibular bone was assay chemically 1 day to 36 weeks after compression and neutral plate fixation with a 4-hole stainless steel ASIF/DCP plate. During the first three postoperative weeks calcium content of the cortical bone decreased by an almost significant amount (P less than 0.05); thereafter, calcium values remained subnormal but did not differ significantly from initial postoperative values. Hydroxyproline content increased steadily throughout the experiment (P less than 0.001). The changes in chemical composition of the bone were of the same magnitude after compression and neutral plate fixation. The results suggest that the cancellous transformation of cortical bone, known to take place under rigid plates, reflects an active remodelling process of the bone in which the calcium and hydroxyproline content changes only slightly.

Animals↗
PubMed1978

Studies on mechanical strength of bone. II. Torsional strength of cortial bone after rigid plate fixation with and without compression.

Biomechanical properties of intact rabbit tibio-fibulae were investigated with torional loading 1 day to 36 weeks after fixation using 4-hole stainless steel ASIF/DCP plates with and without compression. During the first 12 weeks energy absorption and torque moment increased slightly as a result of subperiosteal new bone formation following application of the plates. There was a concomitant increase in the yielding properties of the bone, reflecting progressive porotic transformation. Thereafter, up to 36 weeks postoperatively, the values for energy absorption, torque moment and angular deformation gradually declined in both groups of bones. The differences between normal control bones and plated bones at 36 weeks were 70.1, 53.0 and 26.3 per cent, respectively. The decay of torsional strength was the same whether or not compression was used in the plate fixation. The results suggest that even in normal bone rigid plates induce a considerable loss of strength due to the cancellous transformation they are known to cause in cortical bone.

Animals↗
PubMed1978

Fixation of pelvic fractures and dislocations. An experimental study on the loading of pelvic fractures and sacro-iliac dislocations after external compression fixation.

A trapezoid external compression fixation frame, assembled with the Hoffman instruments, was used for stabilizing experimental injuries to the pelvic skeleton of ten cadaver specimens. The resistance to loading in a position corresponding to upright standing was tested in 17 experiments and related to the calculated load in vivo. The results indicated that ipsilateral injuries, either presenting as dislocations of the sacro-iliac joint and symphysis or as unilateral fractures of the sacrum or ilium in combination with fractures of the pubic rami could be stabilized by the external compression frame well enough to permit weight-bearing in the upright standing position. Bilateral injuries to the pelvic skeleton, vertical or oblique, could not, however, be stabilized enough to resist more than a fraction of the normal load in the upright standing position.

Aged↗
PubMed1978

Structural changes in intact tubular bone after application of rigid plates with and without compression.

The influence of a rigid plate on the structure of intact tubular bone was studied in forty adult rabbits using a four-hole commercial-steel DCP-ASIF plate attached to each tibiofibular bone, with and without compression. The morphological changes in the bone underlying the plate were examined and were assessed quantitatively at one day to thirty-six weeks after operation. The rigid plate induced porotic changes in the cortical bone, which were evident three weeks after the operation and increased rapidly between twelve and eighteen weeks. At thirty-six weeks, resorption cavities occupied 40.6 per cent of the cortical wall of the bones plated with compression and 41.2 per cent of the wall of those plated without compression. The changes were visible slightly earlier in the presence of compression. A rigid plate brought about a statistically significant increase both in the outer diameter of the bone and in the diameter of the medullary space as a result of subperiosteal new-bone formation and concomitant subendosteal bone resorption.

Animals↗
PubMed1978

Effect of rigid plate fixation on structure and mineral content of cortical bone.

The effect of rigid plate fixation on the structure and mineral content of cortical bone were studied by light and fluorescence microscopy and by chemical analysis of calcium and hydroxyproline content in 27 rabbits from one day to 17 weeks after the attachment of a 5 hole ASIF-plate onto intact femur. Between the second and seventeenth postoperative weeks the plated cortical bone became progressively thinner and porotically transformed. Subendosteal resorption was partly offset by the formation of new subperiosteal bone that resulted in a slightly wider than normal, thin-walled tubular bone. At 17 weeks the mean calcium content of the tubular bone under the plate was 15% less than the initial postoperative content (p less than 0.05). The corresponding decrease in calcium content in the metaphyseal and epiphyseal areas of both the operated and the control bone was highly significant. The mean values for hydroxyproline in plated and control bones remained largely unchanged.

Animals↗
PubMed1978

Ectopic ossification after hip arthroplasty.

The incidence of radiographically visible ectopic ossification around the hip joint was redorded in 145 hip joints of 132 patients treated by endoprosthetic replacement. There were 56 total hip replacements with a McKee-Farrar and 39 with a Brunswik type of endoprosthesis; in a further 50 hips the femoral head was replaced with a Moore or Thompson prosthesis. An identical antero-lateral surgical approach was used in all, without detachment of the greater torchanter. The patients were re-examined 3, 6, and12 months after the operation. The extent of ectopic ossification was graded from 0 to III and correlated with pain and with the function and mobility of the operated hip. Ectopic ossification of varied extent was recorded in 37 % after total hip replacement and in 38 % after replacement of the femoral head. Of these ossifications 95 % were recognizable within 3 months; they did not increase in size, but often in density during the following months. One case of bony ankylosis was noted. Ectopic ossification of slight (grade I) to moderate (grade II) degree did not cause pain or affect the function of the operated hip, but reduced the mobility of the affected hip. The difference in mobility between grade I and grade II was significant (p less than 0.05), and between grade 0 and grade II highly significant (p less than 0.001).

Aged↗
PubMed1975

External fixation of the pelvic girdle with a trapezoid compression frame.

The compression obtained with external anchorage in the anterior and posterior part of the pelvic girdle has been studied with a measuring device in the sacroiliac joint and and the symphysis of a specimen pelvis. Two models of external frames were tested, in both of which anchorage to the pelvic bone was brought about with 3 pins inserted in the iliac crests. The results were best with a trapezoid frame and bar exerting a compressive force on the pelvic girdle. When mounted with an inclination of 70 degrees to the long axis of the body, the frame exerted considerable compression on the posterior part of the pelvic girdle. This mounting afforded good stability of the detached hemipelvis. The trapezoid compression frame is recommended as an alternative to conventional methods of treating unstable fractures and dislocations of the pelvic girdle.

Adult↗