Biomedical subjects

U Lindgren

Publications and source records attributed to U Lindgren.

At least 37 records · Page 2Linked to original sources

PubMed1987

Trauma type, age, and gender as determinants of hip fracture.

We determined the trauma type of femoral neck and trochanteric fractures in men and women aged greater than or equal to 20 years in 19, 128 fractures reported to a computerized medical information register during 1972-1981. We found that the earlier known exponential increase of fracture incidence by age started in early adulthood rather than during middle age. An age-related increase was found for each type of injury as well, although the incidence of fractures resulting from severe trauma increased less than that of fractures associated with moderate trauma. The incidence of low-energy fractures in men as well as in women displayed a constant increase rate with age from young adulthood on, impugning the widely held belief that the menopause is a significant risk factor for fractures. The dominating risk factor for proximal femoral fracture in adults appears to be age, irrespective of the cause of injury, with a chronological decline in bone strength as the most likely cause of the exponential increase in the fracture incidence during adult life.

Accidental Falls↗

PubMed1987

Myositis ossificans after total hip replacement and perioperative muscle ischemia.

It has been suggested that muscle ischemia could contribute to myositis ossificans and that the ischemia could result from prolonged retraction during surgery. Biopsy specimens of the gluteus medius muscle were taken at the beginning and the end of 30 primary total hip arthroplasties and the intracellular lactate and phosphocreatine (PCr) measured. Postoperative myositis ossificans was classified according to Brooker after 1 year, and the surface of the heterotopic bone projected above the greater trochanter in an anteroposterior roentgenogram was measured by planimetry. The findings suggest that muscle ischemia is not an important cause of myositis ossificans after hip arthroplasty, but elevated levels of lactate and lowered levels of intracellular PCr may occur as nonspecific responses to tissue trauma that through other mechanisms may lead to ossification.

Aged↗

PubMed1987

Compression-screw arthrodesis of the first metatarsophalangeal joint of the foot.

The function of the foot is disturbed by a stiff, painful great toe. This problem can be overcome with a new technique for fusing the first metarsophalangeal joint at the desired angle with the joint surfaces conservatively resected with parallel, oblique cuts. The bones are then approximated and fixed in 20 degrees-30 degrees of dorsoflexion with two compression screws. The operation should shorten the toe 1.0 to 1.5 cm and give it a moderately valgus orientation. No additional fixation is used. Twenty patients were treated in a prospective study, and all fusions healed. After one year, 13 patients were free of symptoms, five had minimal symptoms, and two still had pain; poor results may be related to the malposition of the fused joint. The technique was simple, involved limited discomfort for the patient, and generally produced a functioning forefoot.

Adult↗

PubMed1987

Age- and sex-specific incidence of femoral neck and trochanteric fractures. An analysis based on 20,538 fractures in Stockholm County, Sweden, 1972-1981.

The risk of fracturing the proximal femur is high for individuals with metabolic bone disease or with low bone mass associated with advanced age. Incidences of 20,538 trochanteric and femoral neck fractures in adult Swedish men and women, from a computerized medical information register for all hospitals in Stockholm County, were analyzed for age- and sex-dependence. The rate of increase in the occurrence of fracture was nearly constant for both sexes, exponentially increasing with age for men over 20 years old and for women over 30 years old. The incidence of trochanteric and femoral neck fracture for men doubled every 7.8 and 7.0 years, respectively. The doubling rate of fracture incidence for premenopausal women, aged 30 to 49 years, did not significantly differ from that for postmenopausal women, aged 50 to 69 years. These findings suggest that age-associated factors common to both sexes provide the main risk for fracturing the proximal femur. Menopause does not pose a major risk.

Adult↗

PubMed1986

Prevention of ectopic bone formation by local application of ethane-1-hydroxy-1,1-diphosphonate (EHDP): an experimental study in rabbits.

This report shows that ectopic bone formation, a serious problem in orthopedic surgery, can be controlled in an animal model by local application of EHDP (disodium-ethane-1-hydroxy-1,1-diphosphonate). The results might be particularly pertinent to the clinical problem of preventing the recurrence of ectopic bone after surgical excision. Male New Zealand white rabbits were treated with immobilization and intermittent passive manipulation of the right knee. The treatment caused bone formation in the quadriceps muscle, which was visible on radiographs after 3 weeks. In this model, the effect of methacrylate implants containing EHDP was studied. A concentration of 16 g EHDP/100 g methacrylate inhibited bone formation in experimental cortical defects. Release of radiolabeled EHDP was studied in an in vitro system. The release of the drug was approximately 20 mg/day and implant initially, decreasing to about 0.1 mg/day/implant after 30 days. Standardized implants containing 16 g EHDP/100 g were then surgically attached to the femur, and the ectopic bone formation created by immobilization and intermittent manipulation was compared with that in rabbits treated with implants but without EHDP. The ectopic bone was measured from lateral and frontal radiograms and from radiograms of serial transverse sections of the thigh. We found that the EHDP implants were capable of preventing major ectopic bone formation in all cases, whereas all rabbits with an implant containing no EHDP had substantial ectopic bone formation at the end of the experiment. There was no difference between groups in the relative amount of cartilage, connective tissue, and normal bone. We conclude that local administration of EHDP may be a useful method for prevention of ectopic bone formation under the conditions and time employed.

Animals↗

PubMed1986

Hip fracture incidence in Stockholm 1972-1981.

We studied the incidence of cervical and trochanteric hip fractures in Stockholm, Sweden from 1972 through 1981. The material, selected from a computerized medical information register, consisted of 11 812 cervical fractures and 8094 trochanteric fractures. The incidence did not change in the age group 50-74 years. In males 75 years of age and older, the incidence of both fracture types caused by moderate trauma increased annually by 5-6 per cent. In females 75 years and older, the incidence of trochanteric fractures caused by moderate trauma increased annually by 6 per cent, whereas the incidence of cervical fractures increased only marginally.

Accidents, Home↗

PubMed1986

Wear of the acetabular socket. Comparison of polyacetal and polyethylene.

Frictional characteristics of polyacetal (Delrin) sockets and of ultra-high molecular weight polyethylene sockets retrieved in revision after aseptic loosening were compared with measurements of friction in new sockets. Friction in retrieved polyacetal sockets was twice as great as in retrieved polyethylene sockets. We also found that frictional characteristics of polyacetal changed as the material aged in vivo. In contrast, friction in polyethylene sockets remained fairly constant, even though most of them contained bone-cement particles. Friction in polyacetal sockets may be important for the relatively high incidence of socket loosening of the Christiansen prosthesis. Measurements of wear of the polyacetal sockets showed a mean annual dimensional change of 240 mm3, four times greater than that reported for the Charnley polyethylene acetabular prosthesis.

Acetabulum↗

PubMed1986

Epidemiology of diaphyseal femoral fracture.

The incidence of diaphyseal femoral fracture in adults, aged 20 years and older, was determined in Stockholm County using hospital admission rates. The validity of the data was investigated by a study of the medical records of a sample of 277 cases and also by determining the incidence in a subpopulation of 139 cases using an alternative method. The incidence decreased from age 20 to middle age after which it increased into old age. The age-related increase was more pronounced in women and in fractures caused by moderate trauma. From 1972 to 1981, the incidence of diaphyseal femoral fracture caused by moderate trauma increased annually by 10 per cent in women aged 75 years and older.

Adult↗

PubMed1985

The effect of prednisolone on kidney calcification in vitamin D-treated rats.

Glucocorticoids are often used to treat hypercalcemia due to vitamin D overdosage. We measured the effect of 1.5 mg/day of prednisolone on the amount of calcium deposited in the kidney of rats dosed with either 500 ng/d or 2000 ng/day of 1-alpha OHD2 or 1-alpha OHD3. The rats were given a diet containing 0.3% calcium and 0.5% phosphate. A second group of rats received 2000 ng/d of the vitamin D analogs and a diet which contained only 0.02% calcium. After 6 weeks, rats given the vitamin D analogs had two to six times more calcium in the kidney compared with the controls (0.096-0.276 mg vs. 0.240-1.064 mg). When a pharmacological dose of prednisolone was added to treatment, calcium in renal tissue increased to 0.305-3.083 mg. The urinary output of calcium seemed to be increased by prednisolone whereas the serum calcium was lowered. It appears that glucocorticoids given at the same time as vitamin D compounds increases the risk for nephrocalcinosis possibly due to increased amounts of calcium in the urine.

Animals↗

PubMed1985

Diclofenac for pain after hip surgery.

Sixty-eight patients were studied during the day after hip replacement for arthrosis. No pain reliever was allowed within 4 h prior to initial assessment of pain. An injection of diclofenac 75 mg, pethidine 50 mg, or placebo was given intramuscularly, and a second injection was usually given after 3.5 h. Pain was recorded before and for 3 h after these injections. Ten patients in the placebo group demanded rescue drug because of insufficient pain relief. Four patients discontinued the study due to side effects: nausea (one patient in the placebo group) and somnolence or nausea (three patients in the pethidine group). Assessed both by visual analogue scale (VAS), and by the investigator's assessment, the diclofenac group had less pain than the pethidine and placebo groups. Side effects were least frequent in the diclofenac group. This study demonstrates that at the doses used here, compared with pethidine, diclofenac is more effective in relieving postoperative pain and has fewer side effects.

Aged↗

PubMed1985

1 alpha-Hydroxyvitamin D2 is less toxic than 1 alpha-hydroxyvitamin D3 in the rat.

An LD50 of 0.2 mg/kg body wt has been determined for 1 alpha-hydroxyvitamin D3 in the rat. In comparison, the LD50 for 1 alpha-hydroxyvitamin D2 is between 3.5 and 6.5 mg/kg. In terms of chronic toxicity, 1 alpha-hydroxyvitamin D3 at a dose of 5 micrograms/kg/day causes death of one-half the animals in a 4-week period. On the other hand, 20 micrograms/kg/day of 1 alpha-hydroxyvitamin D2 is required to induce similar toxicity. The body weight record and renal calcium accumulation during chronic treatment support the above conclusion. It therefore appears that 1 alpha-hydroxyvitamin D2 is between 5 and 15 times less toxic than 1 alpha-hydroxyvitamin D3. This surprising result prompted a reexamination of the relative biological activity of 1 alpha-hydroxyvitamin D2 and 1 alpha-hydroxyvitamin D3. Both compounds are equally potent in the stimulation of intestinal calcium transport, bone calcium mobilization, in the elevation of serum phosphorus, and in the healing of rickets in the rat. The reason for lower toxicity of 1 alpha-hydroxyvitamin D2 is unknown. The results suggest that 1 alpha-hydroxyvitamin D2 might represent a therapeutically superior compound.

Animals↗

PubMed1984

Total body and regional bone mineral by dual-photon absorptiometry in metabolic bone disease.

Dual-photon absorptiometry (153Gd) was used to measure bone mineral of the total body and major anatomical areas. Patients with osteoporosis (male = 11, female = 18) and with renal osteodystrophy (n = 17) were significantly below (20%) normal females (n = 72) and males (n = 13) at most sites. In the osteoporotic patients, but not the renal patients, there was preferential osteopenia of the spine. Bone loss in all anatomical areas became evident after the menopause with an annual loss rate of about 0.7%.

Absorption↗

PubMed1984

Does bone measurement on the radius indicate skeletal status? Concise communication.

Single-photon (I-125) absorptiometry was used to measure bone mineral content (BMC) of the distal third of the radius, and dual-photon absorptiometry (Gd-153) was used to measure total-body bone mineral (TBBM), as well as the BMC of major skeletal regions. Measurements were done in normal females, normal males, osteoporotic females, osteoporotic males, and renal patients. The BMC of the radius predicted TBBM well in normal subjects, but was less satisfactory in the patient groups. The spinal BMC was predicted with even lower accuracy from radius measurement. The error in predicting areal density (bone mass per unit projected skeletal area) of the lumbar and thoracic spine from the radius BMC divided by its width was smaller, but the regressions differed significantly among normals, osteoporotics, and renal patients. There was a preferential spinal osteopenia in the osteoporotic group and in about half of the renal patients. Bone measurements on the radius can indicate overall skeletal status in normal subjects and to a lesser degree in patients, but these radius measurements are inaccurate, even on the average, as an indicator of spinal state.

Adult↗

PubMed1983

Factors leading to rearthroplasty in a material with radiographically loose total hip prostheses.

The present project was undertaken in an attempt to analyse factors associated with clinical failure (defined as indication for rearthroplasty) of total hip arthroplasties when radiographic loosening of the femoral component was present. Out of 79 radiographically loose femoral components the rate of failure was 23 per cent. High viscosity bone cement was negatively correlated to clinical failure whereas male sex and high body weight was positively correlated to clinical failure. Signs of loosening appearing early in the period of observation significantly more often led to clinical failure than late appearance of loosening, which was encouraging for the long-term prognosis.

Body Weight↗

PubMed1983

Factors associated with calcar resorption in cemented total hip prostheses.

Patient data and radiograms from a series of 237 total hip replacements were evaluated by means of a computer program. Middle-aged patients and those without other dysfunctions of the lower extremities than the primary hip disease were prone to develop calcar resorption. Patients who did not use supportive aids preoperatively and subjects doing well without aids postoperatively were more frequently represented in the group with calcar resorption. The CAD-prosthesis (Computer Assisted Design, Howmedica), was positively correlated to resorption at calcar at 6 months postoperatively compared to the Charnley-Müller prosthesis. A negative correlation to valgus oriented femoral components was noted. Vertical placement of the acetabular cup, large cups and a long distance between the femur and the pelvis was noted to occur more often in the group with calcar resorption. Mechanical factors are concluded to be predominant in early calcar resorption and are suggested to be of clinical importance for the long term results.

Bone Resorption↗

PubMed1983

Factors associated with early loosening of cemented total hip prostheses.

Patient data and radiograms from a series of 237 consecutive total hip replacements were evaluated by means of a computer programme in an attempt to study factors correlated with early loosening. We found that the loosening rate was significantly influenced by several factors. The CAD-prosthesis (Computer Assisted Design, Howmedica) was found to be superior to the Charnley-Müller-prosthesis. The viscosity of the cement seemed to be an important factor in that low viscosity was positively correlated to loosening whereas high viscosity showed a negative correlation. Several technical details in the performance of the operations as well as loosening correlated with the surgeon. Males who preoperatively had fairly unrestricted physical activity and high body weight were more prone to early loosening. No correlation was found with the diagnosis, previous hip surgery, age, osteoporosis or cortisone treatment preoperatively. We wish to underline the importance of a thorough technique and suggest that total hip replacement should be performed by specialized surgeons.

Body Weight↗

PubMed1983

Factors associated with heterotopic bone formation in cemented total hip prostheses.

A series of 237 total hip replacements were analysed by means of a computer program. High body weight and postoperative fever, as well as several indications of a technically demanding operation, occurred significantly more often in the group of patients which developed paraarticular ossification postoperatively. The results point to a causal relation between tissue trauma and heterotopic bone formation. We wish to underline the importance of a gentle handling of tissues in the performance of a total hip replacement if the rate of ectopic bone is to be reduced to a minimum.

Bone Cements↗

PubMed1983

A new operation for hallux valgus.

A distal oblique osteotomy on the first metatarsal, with lateral displacement of the metatarsophalangeal joint and internal fixation with a compression screw, was performed. No splint or plaster was used. The operation is relatively simple and effective. Pain and discomfort during a short healing period are minimal. Forty-nine feet were operated on in 42 patients by eight surgeons. The patients were advised to bear full weight after six weeks. Return to unlimited work was possible after six weeks. The complications were superficial infection in one case and screws entering the metatarsophalangeal joint in two cases. One patient complained of metatarsalgia after the operation, but all other patients were satisfied after follow-up periods ranging from three months to six years.

Adolescent↗