Biomedical subjects

K Aalto

Publications and source records attributed to K Aalto.

29 records · Page 2Linked to original sources

PubMed1984

Experimental epiphyseal separation by torsional force.

Separation of the proximal tibial epiphysis from the metaphysis by torsional force was experimentally studied using cadaver bone preparations from 19 adolescent sheep. The energy needed to displace the epiphysis increased in correlation with an increase in the age of the animal. The separated epiphyseal and metaphyseal surfaces were examined using scanning electron microscopy. In the younger animals the separation line passed through the area of hypertrophied chondrocytes. In the animals more near skeletal maturity the separation occurred in a more sinuous fashion and also through spongious bone.

Age Factors↗

PubMed1984

Changes in erythrocyte sedimentation rate and C-reactive protein after total hip arthroplasty.

Uncomplicated total hip arthroplasty (THA) was performed in 40 osteoarthritic patients, and changes in erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were registered. The follow-up period was one year. Preoperative ESR appeared to be slightly elevated, and CRP levels were normal, with no exceptions. A postoperative maximum ESR of 64 mm/hour was reached six days after surgery. A slow decrease followed, but ESR remained slightly elevated one year later. The changes in CRP were more rapid; a maximum of 134 mg/l was registered on the second day after surgery, and the values were consistently normalized three weeks after surgery. Thus, uneventful recovery after THA seems to be indicated by a normalizing CRP, regardless of ESR values.

Aged↗

PubMed1983

The deformation of external fixation devices during loading.

The stability of four different types of external fixation devices was studied when they were subjected to torsion, bending and deformation under axial compression. The most stable fixation was achieved when the bone ends were in contact. The frames were weakest when the stress was applied at right angles to the plane of the frame. All four had adequate stability for fracture healing.

Fracture Fixation↗

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↗

PubMed1980

Classification of ankle fractures in children.

The roentgenograms of 310 children treated for ankle fractures were evaluated for grouping according to the classifications of Ashhurst-Bromer-Weber, Lauge-Hansen, and Salter-Harris. The mean age of the children at the time of injury was 11.1 years (range 2-14 years). Two hundred twenty-one (71.3%) children had malleolar fractures, 71 (22.9%) had tibial epiphyseal fractures, and 18 (5.8%) had syndesmotic lesions. The age distribution of fractures was typical: malleolar fractures predominated among the younger children, epiphyseal fractures among the older. Only the oldest children had avulsion fractures of the syndesmosis. Grouping of the fractures according to Lauge-Hansen and Ashhurst-Bromer-Weber, classifications suited to adults was largely unsuccessful. Epiphyseal fractures, moreover, were easily classified according to Salter-Harris. In spite of their complexity, ankle fractures in children can be roughly divided into avulsional and epiphyseal fractures. Adequately reduced avulsional fractures can be expected to heal well; epiphyseal fractures, however, may five rise to late complications. We propose, therefore, that ankle fractures in children be classified on the basis of roentgenological findings with respect primarily to epiphyseal lesions as well as on an additional simple grouping as to risk for clinical purposes: Group I, low risk, avulsional fractures and epiphyseal separations; Group II, high risk, fractures through the epiphyseal plate.

Adolescent↗

PubMed1979

Meniscectomy in children.

The results of 42 meniscectomies in 41 children were evaluated 1 to 13 years (mean 5.6 years) after the operation. At the follow-up 11 patients (12 operated knees) had complaints. In four of these patients, all having had removel of the lateral meniscus, roentgenological examination revealed degenerative changes. The results of the clinical and roentgenological follow-up examination showed that insufficiently rigorous appraisal of the indications for surgery had led, in some cases, to unnecessary meniscectomies. The results of operations had not always been satisfactory. The reliability of arthrographic findings alone as an indication for surgery are discussed and the indications for operative treatment are presented.

Adolescent↗

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

Supracondylar fracture of the humerus in children. A long-term follow-up study of 107 cases.

A total of 107 cases of supracondylar fracture of the humerus in children were examined after a follow-up period of 8 to 18 years. No serious complications were found. Conservative treatment gave good results, and open reduction was seldom indicated. Rotational displacement and displacement in the frontal or sagittal plane remodelled by the end of the growth period, whereas tilting of the distal fragment into varus or valgus remained. The position of reduction should be checked roentgenologically until bony consolidation occurs, by measuring Baumann's angle or the carrying angle, and rereductions should be performed within 2 weeks.

Adolescent↗

PubMedDate not supplied

Leg lengthening by osteotomy and gradual distraction: an experimental study.

Osteotomy and gradual distraction of the distal radius was performed on 12 sheep. After 3-6 weeks of daily distraction by external fixation, lengthening of 0.5-1.8 cm was achieved. Three weeks after distraction was begun, striae of new bone, organized in the direction of the distraction, were noted radiologically. The bony consolidation developed from the osteotomized bone ends to the center of the distraction area. Medullary structures also contributed to bone formation in the distraction area. Collagen bundles, organized in the direction of distraction, formed a template for the developing bone. The medullary canal remodeled 16 weeks after the operation. Solid bone formed after the distraction procedure with no additional bone transplantation.

Animals↗

PubMedDate not supplied

Acute patellar dislocation in children: incidence and associated osteochondral fractures.

In a prospective two-year study on urban (city of Helsinki) Finnish children, 72 acute patellar dislocations were observed. The calculated annual incidence rate was 43/100,000 in children under 16 years. A total of 28 knees (39%) had associated osteochondral fractures. These fractures comprised 15 capsular avulsions of the medial patellar margin and 15 loose intra-articular fragments detached from the patella and/or lateral femoral condyle. The intra-articular fragments were found only after spontaneous relocation of the patella. The femoral fracture constantly involved the edge of the articular surface in the middle third of the condylar arc.

Adolescent↗

PubMedDate not supplied

The cartilaginous femoral sulcus in children with patellar dislocation: an ultrasonographic study.

One hundred and sixteen knees of 33 patients with patellar dislocation and 25 normal children 12-18 years of age were examined by ultrasonography to measure the cartilaginous sulcus angle on the patellar surface of the femur. In knees with patellar dislocation, the cartilaginous sulcus angle measured between 154 and 195 degrees, exceeding the corresponding values of normal knees (134-153 degrees). In patient knees, the cartilaginous sulcus was also consistently wider than the underlying osseous sulcus. This suggests that in pediatric patients with patellar dislocation, the actual patella-stabilizing ability of the femoral sulcus is weaker than the osseous outline in axial radiographs would lead one to suppose. It would appear also that by measuring the cartilaginous sulcus angle of the femur, a clear distinction can be made between normal knee joints and joints displaying patellar instability.

Adolescent↗