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Biomedical subjects

J Merikanto

Publications and source records attributed to J Merikanto.

At least 19 recordsLinked to original sources

Gait asymmetry in patients with limb length discrepancy.

Foot loading patterns and neuromuscular function of both limbs during walking were investigated on 25 patients with limb length discrepancy. Plantar pressures and 2-D ground reaction forces were recorded simultaneously with electromyographic activities at two different walking speeds. Bilateral comparison indicated that moderate limb length discrepancies resulted in asymmetrical gait patterns. The duration of the stance phase was reduced in the short limb in both walking speeds. The vertical ground reaction force (F) in the push-off phase was greater in the long limb both at normal (1.33 (SO, 0.05 BW) vs. 1.29 (SD, 0.09 BW)) (P=0.0027) and fast walking speed (1.55 (SD, 0.11) vs. 1.48 (SD, 0.15 BW)) (P=0.001). Peak plantar pressures were higher under the big toe in the long leg and the heel-off occurred faster. The push-off phase was initiated earlier in the short leg. The maximum isometric torque of the long limb was considerably greater (673 Nm vs. 239 Nm) (P=0.026). The results imply that the loading of the long limb is greater and the foot loading patterns shifted more to the forefoot in the long, limb to compensate walking disturbances caused by limb length discrepancies.

Adolescent↗

Follow-up of children with cerebral palsy after selective posterior rhizotomy with intensive physiotherapy or physiotherapy alone.

In all 21 children with spastic cerebral palsy (CP) underwent surgery involving selective posterior rhizotomy (SPR), followed by six months intensive physiotherapy (PT). Neurological and physiotherapeutic assessments were made one, three and five years after the operation. The children undergoing surgery were compared to 21 comparison children who took part in a regular physiotherapy programme during the same time period. At the preoperative assessment, the children undergoing surgery were similar to the comparative children in terms of age, sex, type of CP, spasticity of the legs and mean functional scores. The children were selected for SPR on the basis of more than half a year's arrest of motor development, which was the only significant difference to the comparative group. Motor function was measured using two different methods, the Illinois-St Louis Scale and the Gross Motor Functional Classification System (GMFC). Both groups experienced steady development during the five-year follow-up period and no significant differences were observed in the mean functional scores between the groups. We conclude that this comparative study, like most controlled studies, failed to demonstrate any additional effect of SPR on motor development of children with spastic CP. Nevertheless, SPR may contribute to a resumption of motor development in children with arrested motor development despite vigorous conservative therapy. SPR is therefore justified as treatment in selected cases.

Adolescent↗

Intra-familial child homicide in Finland 1970-1994: incidence, causes of death and demographic characteristics.

The purpose of this study was to investigate all child homicides for the 25-year period, 1970-1994 in Finland and to analyse the specific characteristics of the filicide cases. A total of 292 child homicides occurred during this period. In 201 (69%) cases the offender was a parent or a stepparent of the child. Altogether, 173 (59%) of the victims were boys and 119 (41%) were girls. For the closer examination of the filicide cases we excluded the neonaticide and homicide-suicide cases. Consequently, we report on 70 filicide victims. Of these victims, 42 (60%) were boys and 28 (40%) were girls. Twenty six (37%) of the children were killed before the age of 1 year and 53 (79%) before the age of 5 years. The offender was the mother in 43 (61%) cases and the father or the stepfather in 26 (37%) cases. The victims of the mothers were younger than those of the fathers. The most frequent causes of death were head injuries, drowning and suffocation. The most common means of assault were battering, drowning and strangulation. One in two of the fatally battered children had a documented history of previous abuse.

Adolescent↗

Treatment of renal cysts with single-session percutaneous drainage and ethanol sclerotherapy: long-term outcome.

OBJECTIVES: To evaluate the safety, efficacy, and long-term outcome of single-session ethanol sclerotherapy for non-neoplastic renal cysts. METHODS: In a prospective study, 32 patients with a simple renal cyst were treated with ultrasound-guided percutaneous aspiration, and no more than 100 mL sterile 99% ethanol was injected into the cyst. The procedure was performed under local anesthesia, and the patients were hospitalized overnight. The serum concentrations of alcohol immediately after the sclerotherapy and 1 hour later and the corresponding urine concentrations were measured. The mean follow-up period was 55 months (range 12 to 156). Control checkups were scheduled at 1, 3, 6, 9, and 12 months after the sclerotherapy. During the control visits, the patients underwent ultrasound measurement of the size of the cyst. The history concerning renal pain especially was evaluated by the urologist. The patients were asked if they did or did not have pain. The severity of pain was not evaluated. RESULTS: Sclerotherapy with ethanol was performed successfully in all 32 patients with a simple renal cyst. The cyst disappeared completely in 7 patients (22%). The mean size of all cysts decreased from 7.8 cm (range 3 to 16) to 1.7 cm (range 0 to 9; P <0.0001). Before the sclerotherapy, 24 patients had symptoms due to the cyst, and 18 of these (75%) were asymptomatic after the ethanol sclerotherapy. In 2 patients the pain decreased, 2 patients were without change, and in 2 patients the pain increased. There was no correlation between the size of the cyst and the intensity of pain. No major complications occurred. The serum concentration of alcohol varied from 0 to 0.30 g/L and that in urine from 0.04 to 0.27 g/L. CONCLUSIONS: Percutaneous aspiration and sclerotherapy with ethanol for simple renal cysts is simple, fast, safe, effective, and inexpensive. The results are comparable to those reported earlier. The treatment is without major complications. We propose sclerotherapy with 99% ethanol as the primary treatment of simple renal cyst. The treatment can be done in an outpatient clinic.

Adolescent↗

Use of self-reinforced polylactide osteosynthesis devices in craniofacial surgery: a long-term follow-up study.

Self-reinforced polylactic acid or polylactide (SR-PLA) is a biodegradable polymer, which is strong enough to fix weight-bearing cortical bone fractures and osteotomies. We report our experience and follow-up of the use of SR-PLA plates in 15 clinical cranioplasties. Two of the cases are described in greater detail. In one of them SR-PLA plates were used in addition to titanium plates, and in the other an SR-PLA plate fixed with mini-titanium screws was used as the only fixation material. In the other patients SR-PLA plates or wire were used in addition to titanium. So far no complications have been observed in these 15 patients. The only small superficial fistula was associated with a titanium plate and titanium screws. The longest follow-up has been over eight years. Recent results show metal-like deformation properties in addition to complete late resorption, making SR-PLA osteosynthesis devices promising for use in craniofacial surgery.

Absorbable Implants↗

Effect of hypertension and risk factors on diameters of abdominal aorta and common iliac and femoral arteries in middle-aged hypertensive and control subjects: a cross-sectional systematic study with duplex ultrasound.

There is a general tendency towards atherosclerosis and arterial dilatation in older age, and high blood pressure also tends to increase arterial diameters. The purpose of this study was to examine the effect of hypertension and other cardiovascular risk factors on aortic, common iliac and common femoral artery diameters. The diameters of the abdominal aorta and the iliac and femoral arteries and the extent of echogenic plaques in the aorta and the iliac arteries down to groin level were evaluated with ultrasound in 1007 middle-aged (40-60 years) men (505) and women (502), 496 with arterial hypertension and 511 controls. Twenty-eight subjects were excluded because of poor visualization. Men had significantly larger diameters of the abdominal aorta (mean 21.3+/-2.8 vs. 17.8+/-1.3 mm) and the common iliac (13.4+/-2.0 vs. 12.2+/-1.2) and common femoral arteries (11.0+/-1.4 vs. 9.7+/-0.9) than women (P for all <0.001), but arterial diameter was also related to the subject's size. Atherosclerotic plaques, age and height were associated with the diameter of the abdominal aorta in men, while high body mass index (BMI) had less significance. The diameter of the aorta was larger in hypertensive men aged 56-60 than in controls of the same age. In women, height, BMI and diastolic blood pressure (DBP) were associated with the diameter of the aorta, while systolic blood pressure (SBP) had less and age no effect. Age, plaques, height, BMI, DBP and SBP were associated with the diameters of the common iliac arteries in both genders, while smoking had an inverse correlation. The results on lipid values were inconsistent and an abnormal glucose tolerance test proved nonsignificant. In conclusion, arterial size measured as a diameter related to the subject's size was larger in men. Age, arterial plaques and blood pressure increased arterial diameter significantly. However, the hypertensive disease itself had only a minimal effect. The changes were smaller in women than in men.

Adult↗

Antidromic corticospinal tract potential of the brain.

OBJECTIVE: To describe a novel potential component (antidromic corticospinal tract potential, ACSP) of the brain after translaminar spinal stimulation of a relaxed patient during scoliosis surgery. To study the origin of this component and to compare its source to known sources of the somatosensory evoked potentials (SEPs). METHODS: We studied 17 consecutive patients during posterior scoliosis surgery. SEPs and ACSPs were elicited by translaminar spinal stimulation at the Th 2 and L 1 levels. ACSPs and SEPs were recorded on the scalp midline. Neurogenic motor evoked potentials (NMEPs) were recorded on the popliteal spaces. Preoperative tibial SEPs were also recorded. RESULTS: ACSP was distinctly separated from the corresponding spinally evoked cortical SEP that showed longer latency than the ACSP. ACSPs decreased and disappeared when stimulation was moved to the caudal direction in the conus region while SEP persisted. In addition, the hemispheric origin of ACSP was confirmed with multichannel midline recordings of the scalp and neck. Thus there was no confusion to the response of nucleus gracilis, corresponding the P 31 response of the tibial nerve SEP. CONCLUSIONS: The origin of ACSP seemed to be in the rostral part of the corticospinal tract. ACSP diminished in the conus region when stimulation was moved caudally and it disappeared when the stimulus was given to the root level. This proves that ACSP is not a response of the somatosensory tract, instead ACSP represents antidromic response of the pyramidal tract. ACSP can be used in monitoring of the motor tracts during scoliosis surgery together with NMEPs.

Adolescent↗

Interobserver, interequipment and intersubject variability of echo-Doppler examination of the common carotid and vertebral arteries.

OBJECTIVE: We evaluated interobserver and interequipment variability in common carotid and vertebral flow measurements, using seven female members of nursing staff as subjects, four different ultrasound machines and three different radiologists as operators. METHODS: The flow of the common carotid and vertebral arteries in each subject was examined at 0, 10, 20 and 30 min after lying down in a supine position. Peak velocity, end-diastolic velocity, mean velocity, systolic acceleration, cross-sectional area of the vessel, flow volume/min, resistance index and Doppler angle were measured. RESULTS: A large proportion of the variance of peak velocity, cross-sectional area of the vessel and flow volume was patient-related. Significantly different values of end-diastolic velocity, mean velocity, resistance index, Doppler angle and systolic acceleration were obtained with different equipment. Significantly different values of systolic acceleration, vertebral peak velocity, common carotid artery flow and Doppler angle were obtained by different operators. However, part of the variability may be physiological due to the study protocol. CONCLUSION: The use of the same operator and equipment is recommended in follow-up examinations.

Analysis of Variance↗

Comparison of health-related quality of life in three subgroups of spinal cord injury patients.

Health-related quality of life (HRQL) was evaluated in three subgroups of spinal cord injury (SCI) patients: (1) persons who had sustained a pediatric SCI (mean time from injury 20 years, age at injury 11.3 years, n = 36), (2) newly injured patients at the beginning of acute rehabilitation (mean age 35.3 years, n = 31), and (3) patients with a chronic SCI (mean time from injury 4.8 years, mean age at injury 35.2 years, n = 34). All the patients were clinically examined and structurally interviewed with a list of questions dealing with details of anamnestic information about injury, its treatment, possible complications and persons past and present psycho-social condition. HRQL was assessed by a generic fifteen-dimensional self-administered instrument (15D). The relative importance of the 15D dimensions and an overall judgement of health status were measured by a 0-100 visual analogue scale. Average importance weights of the dimensions of moving and working differed significantly in the three subgroups. Patients with pediatric SCI assigned the lowest importance for moving. The newly injured patients highly valued working capability. The HRQL scores of the patients who had sustained their injury in childhood were significantly higher than those of the newly injured patients or chronic patients. The tetraplegic patients estimated their HRQL significantly lower than patients with incomplete paraplegia. Of the three subgroups studied, those with pediatric SCI were well adjusted on the basis of anamnestic information and scored high on HRQL when compared with the other two subgroups. Patients injured in adulthood rated their overall HRQL lower and were often unable to return to work. Patients injured in childhood expressed better performance in physical functions than patients who had sustained their injury in adulthood. The subgroups did not differ in psychological functions.

Adult↗

Bone mineral status after pediatric spinal cord injury.

The impact of spinal cord injury (SCI) on later bone mineral status was studied in 35 adults who had sustained their injury in childhood. The median age of the patients was 31 years, the median age at injury 12.9 years and the median time period from injury was 19 years. The methods used in the study were clinical interview and examination, measurement of bone mineral density (BMD) of the lumbar spine and the proximal femur with dual energy X-ray absorptiometry (DEXA) and estimation of bone turnover with biochemical markers. The densitometric examination revealed that the BMD at the lumbar spine was within the normal range but grossly decreased in the femoral region. Moreover, there was a significant difference in BMD between patients with high (C2-T6) and low (below T6) lesions in the lumbar spine as well as in the femoral region. Patients with lower lesions had higher BMD values. The markers of bone turnover which were studied were serum and urinary calcium and phosphate serum alkaline phosphatase and its isoenzymes, osteocalcin, carboxyterminal propeptide of human type I procollagen (PICP), carboxyterminal telopeptide of type I collagen (ICTP) and urinary deoxypyridinoline. These markers of bone metabolism showed no signs of ongoing accelerated bone formation or resorption. The present study suggests that caution should be observed in weight bearing training or mobilisation of patients with pediatric SCI or perhaps with long standing SCI because of increased fracture risk. The prevention of dissociated osteoporosis should be investigated further in order to avoid fractures of weakened bones. The modes of prevention might be found in the use of modern pharmacotherapy of osteoporosis and from correctly dosage physical training.

Absorptiometry, Photon↗

Duplex ultrasound in the subclavian steal syndrome.

PURPOSE: The effect of subclavian steal on the contralateral vertebral flow and its possible effect on carotid flow were studied and the US results were compared to the angiographic findings. MATERIAL AND METHODS: The study consisted of the records of 74 patients with a duplex Doppler finding of subclavian steal syndrome. Of these, 48 patients had had both angiography and US of the neck arteries and were selected for comparison. For a comparison of the US flow values, a control series of 48 was selected from our carotid archive and consisted of patients without subclavian steal who had also been examined with both US and angiography. RESULTS: Of the 48 patients, 44 had a subclavian steal syndrome at angiography, 31 on the left side and 13 on the right. Of the 44, 21 patients had subclavian occlusion, and 23 stenosis. In 84% of the subclavian occlusions, US showed a complete systodiastolic steal and in 16% a partial systolic steal, while the corresponding findings for subclavian stenoses were 17% and 83%. Of the 48 cases, 4 were not real subclavian steals: 2 had vertebral occlusion (1 with a 90% subclavian diameter stenosis) on the side of retrograde flow at US and a steal through the vertebral and collateral arteries to the spinal arteries; and 2 had a 70% diameter stenosis of the subclavian artery and to-and-fro flow in the vertebral artery at angiography. In the 21 cases of complete steals, the subclavian diameter stenosis was 97 +/- 8% at angiography, and in the 23 partial steals, it was 85 +/- 10%. There was a significant increase in contralateral vertebral and common carotid flow in the cases with retrograde vertebral flow compared to the vertebral and common carotid flow of the control subjects. The retrograde flow values, the ipsilateral vertebral lumen diameter, and the flow values in the common carotid arteries were higher in complete steals and subclavian occlusions than in partial steals. CONCLUSION: A complete vertebral steal at US correlated well with subclavian occlusion and a partial steal suggested stenosis of the subclavian artery. There were also flow changes in the contralateral vertebral artery and the common carotid arteries that compensated for the steal. Retrograde vertebral flow at US was sometimes associated with vertebral occlusion in subclavian stenosis without a true subclavian steal.

Adult↗

Development of the hip in diastrophic dysplasia.

We examined 50 patients with diastrophic dysplasia both clinically and radiologically. Two legally aborted fetuses were dissected. The mean age of the patients was 16.2 years (newborn to 38) and the mean follow-up was 11.4 years (3 months to 34 years). The fetal hips and MRI of newborn infants showed congruity and no significant joint deformity. Flexion contracture of the hip became evident later in 93% and was progressive. The radiological appearance of the proximal femoral ossific nuclei was delayed and in 17% of males and 28% of females the ossific nuclei had not appeared by the age of 12 years. Radiological measurements differed considerably from reference values and were related to the rapid and progressive restriction of rotational movement and the increase in flexion contracture. The typical findings were flattening and inferomedial bulking of the femoral head and a double-hump deformation. The changes in the hip led to secondary osteoarthritis before early middle age. We describe the clinical and radiological measurements which define the early degeneration of the joint.

Abortion, Legal↗

Effect of hypertension, diabetes and other cardiovascular risk factors on kidney size in middle-aged adults.

The aim of the study was to investigate in a population-based series (1031 subjects, age range 40-60 years) whether the renal size of hypertensive subjects differs from that of control subjects and whether the difference might be due to hypertension itself or risk factors associated with hypertension. The renal measurements were performed by abdominal ultrasound. The genders were analyzed separately. Hypertensive men had slightly larger kidneys than controls (70.1+/-8.9 cm2 vs. 67.9+/-8.7 cm2, p <0.008). The difference was, however, mediated mainly through the body mass index (BMI), whereas hypertension, blood pressure or hypertensive medication did not affect renal size. High serum concentrations of uric acid and creatinine were associated with smaller kidney size (p <0.001 and p <0.05, respectively). Alcohol users had slightly larger kidneys than abstainers, but the difference was not significant. Renal size increased with pack years of smoking. Diabetics had 4.8% larger kidneys (p <0.039), but no difference was observed between the subjects with impaired glucose tolerance and those with normal test results. In multivariate analysis, the most significant factors associated with enlarged kidney size were the fasting blood glucose concentration (p < or = 0.0001), smoking (p < or = 0.0001) and atherosclerotic lesions in carotid arteries (p <0.002). The kidneys were also slightly larger in hypertensive women than in control subjects, but the difference was only of borderline significance (p <0.08). Women on hormone replacement therapy had smaller kidneys than other women (p <0.05), but there was no difference in renal measures between premenopausal and postmenopausal women. In multivariate analysis, the most significant factors contributing to large kidney size were blood glucose concentration (p <0.0001) and smoking (p <0.05), while age and serum creatinine concentration were associated with smaller kidney size (p <0.0001 and p <0.0001). We conclude that renal size is related to sex and the subject's height and weight. Smoking, abnormal glucose tolerance, blood uric acid, creatinine, carotid atherosclerosis and hormone replacement therapy in women were also significant factors for renal size. Hypertensive subjects had larger kidneys than controls, mainly because of their more frequent obesity and abnormal glucose test.

Adult↗

Disc herniation in the lumbar spine during growth: long-term results of operative treatment in 18 patients.

We studied 18 patients who had undergone surgery for herniated lumbar discs between the ages of 11 and 17 years. The inclusion criteria for girls was an age of 15 years or below and for boys 17 or below at surgery. The mean follow-up time was 10 years and the clinical outcome was good. Age at surgery and length of the follow-up had no effect on the result. The radiological disc height at follow-up did not correlate with the follow-up time or age of the patient at operation. MRI scans at follow-up from ten patients operated at less than 15 years of age revealed multilevel disc degeneration but favourable clinical results.

Adolescent↗

The value of MRI in early Perthes' disease: an MRI study with a 2-year follow-up.

Eleven hips in nine patients with Perthes' disease were studied by plain radiography at 3-month and MRI at 6-month intervals over a period of 2 years. The aim was to clarify the value of MRI in estimating epiphyseal involvement and in predicting uncoverage of the epiphysis. Signal intensities of the epiphysis and metaphysis were visually evaluated from T1- (T1W) and T2-weighted (T2W) images. The extent of decreased signal intensity (DSI) in the epiphyses was volumetrically calculated from T1W images and then compared with follow-up radiographs. The area of epiphyseal DSI corresponding best with Catterall's classification was seen by MRI 3-8 months after the first symptoms. MRI images obtained earlier usually showed less involvement than the follow-up radiographs. However, two features predicting extensive epiphyseal necrosis were: (1) DSI on both T1W and T2W images covering over two-thirds of the epiphysis and (2) diffuse bone marrow oedema of the femoral neck and metaphysis. When T1W images showed a reappearance of high signal intensity patches in the lateral quarter of the epiphysis, no clinically significant uncoverage was seen during the follow-up. Extensive epiphyseal necrosis can, therefore, sometimes be predicted by MRI even within the first 3 months, but MRI visualises epiphyseal involvement more clearly 3-8 months after the first symptoms.

Child↗

Ultrasonic and magnetic resonance imaging of fetal sacrococcygeal teratoma.

OBJECTIVE: To evaluate ultrasonic and magnetic resonance imaging (MRI) and Doppler examination in fetal sacrococcygeal teratoma (SCT), in respect to the postnatal findings and histological type of the tumor. STUDY DESIGN: Nine pregnancies complicated by histologically mature fetal sacrococcygeal teratoma in four cases and by immature/malignant teratoma in five cases. Transabdominal ultrasonic imaging and Doppler velocity waveforms were recorded during the second or last trimester in all cases, first trimester ultrasound examination was carried out in six cases and last trimester MRI in five cases. These findings were compared with postnatal and operative findings of the children. RESULTS: Ultrasound examination did not reveal intrapelvic parts of SCT, but this was possible by MRI. Velocity waveforms of the tumor arteries were similar in all histological types and the resistance index varied from 60 to 70. The mean gestational age at antepartal diagnosis was 25.2 weeks. Large tumor size with relatively large proportion of solid components was often recognized in cases with malignant/immature histology. CONCLUSIONS: Antepartal MRI is useful for examination of fetal SCT, but reliable differentiation of mature and immature SCT is not possible antepartally.

Female↗

Critical aspects of neonatal surgery in clubfoot.

Good results after early operative treatment of clubfoot has been reported by some investigators. Most have recommended early conservative treatment and later surgical procedures in resistant cases. Operation immediately after birth is demanding, and the operative team must master all problems of neonatal surgery, anesthesiology, and postoperative care. Conservative treatment in experienced hands may lead to a satisfactory result in one third of cases. We recommend primarily conservative treatment, but patients with resistant cases must undergo operation at age 2-5 months. We need more prospective studies and generally accepted grading systems of results.

Clubfoot↗