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Biomedical subjects

N Dalén

Publications and source records attributed to N Dalén.

At least 19 recordsLinked to original sources

An evaluation of bone loss after total hip arthroplasty for femoral head necrosis after femoral neck fracture: a quantitative CT study in 16 patients.

This study was conducted to determine if bone and muscle loss is reversible in patients who had undergone total hip arthroplasty (THA) owing to necrosis of the femoral head after osteosynthesis for a displaced femoral neck fracture. The cortical bone mineral density (BMD), bone volume, bone mass, and muscle volume of the thigh and the BMD of the distal femur and proximal tibia were measured by quantitative computed tomography in 16 patients. Both extremities were measured just before reoperation. The measurements were repeated 3 and 6 months later. At reoperation, there was a mean 12% relative loss of bone mass and 23% loss of muscle volume in the middle femur on the fractured side compared with the uninjured side. In the distal femur and proximal tibia, there was a relative loss of BMD of 14% and 21% on the fractured side. Six months after reoperation, we found no change in bone mineral at any location on either side. The muscle of the thigh showed a gain in volume of 20% on the reoperated side but no change on the uninjured side. At the time of reoperation, we noted a marked bone and muscle loss on the fractured side. We failed to note any restoration of bone mineral after THA despite remobilization, which is expressed as an increase in muscle volume on the reoperated side. This study indicates that osteopenic bone has difficulties in adapting to patients' improved mobility after reoperation.

Arthroplasty, Replacement, Hip

Low IGF-I levels in hip fracture patients. A comparison of 20 coxarthrotic and 23 hip fracture patients.

We measured total body bone density and body composition with dual energy x-ray absorptiometry in 43 elderly patients, 23 with hip fracture and 20 with coxarthrosis, after surgery and after 6 months. Insulin-like growth factor-1 (IGF-I), a polypeptide known to affect bone metabolism, and two of its binding proteins (IGFBP-1, IGFBP-3) were measured preoperatively and after 6 months. Normal serum IGF-I levels are dependent on adequate nutrition and normal secretion of growth hormone (GH). We found consistently lower levels of IGF-I and IGFBP-3 and a tendency to higher levels of IGFBP-1 in the patients with hip fractures, who also had a lower total body mass, lower fat mass and bone mineral density than the coxarthrosis group, indicating a more catabolic state in the patients with hip fracture, even 6 months after the trauma.

Absorptiometry, Photon

Serum albumin and deep infection in femoral neck fractures. A study of 437 cases followed for one year.

Four hundred and thirty-seven patients with femoral neck fractures were studied to determine the value of serum albumin estimations on admission. Serum albumin is a good predictor of mortality, and patients with low levels should be given additional nutritional support. We found that the serum albumin level is not useful in predicting deep wound infection. The infection rate of 3% does not justify the use of antibiotic prophylaxis in general.

Aged

Bone and muscle mass after femoral neck fracture. A controlled quantitative computed tomography study of osteosynthesis versus primary total hip arthroplasty.

The cortical bone mineral density (BMD), bone volume, bone mass and muscle volume of the thigh, and the BMD of the distal femur and proximal tibia were measured quantified by quantitative computed tomography (QCT) after an operation for a displaced femoral neck fracture. Twenty patients were randomized to osteosynthesis or total hip arthroplasty (THA). Both legs were scanned after 18 months, and the operated side was compared with the healthy side. Clinical assessment was performed with a Harris hip score. A reference group of 9 patients, who had undergone THA because of arthrosis, was chosen. In the fracture patients, we found a 9% decrease in bone mass and muscle volume of the middle femur. The BMD of the distal femur and proximal tibia showed a more marked osteopenia. There was no difference in these parameters between the two groups. In the reference group of operated arthrosis patients, we did not find any differences between sides postoperatively. After the operation, the fracture patients had a lower Harris score than the arthrosis patients, and this was most pronounced among those who had undergone osteosynthesis. The finding of a marked osteopenia after a femoral neck fracture, irrespective of treatment, but no bone loss after THA because of arthrosis, implies that patients with a femoral neck fracture are more sensitive to osteopenia, and that the bone loss is not proportional to the operative trauma.

Aged

Decrease in bone mineral density and muscle mass after femoral neck fracture. A quantitative computed tomography study in 25 patients.

We performed a prospective, longitudinal, quantitative computed tomography (QCT) study of bone mineral density (BMD), cortical bone volume, bone mass and muscle volume in 25 patients who were operated on with osteosynthesis because of a displaced femoral neck fracture. Both legs were scanned within 3 days after the fracture, and 3 and 6 months after the operation. The measurements were performed by a computer tomograph equipped for bone mineral densitometry. We found some side differences among the patients at the time of fracture, but none of the differences was statistically significant. After 6 months, we found reductions in BMD in the distal femur and proximal tibia on the fractured side of 11% and 19%, respectively, as well as a reduction in BMD of 7% in the proximal tibia on the uninjured side. We found no changes in cortical bone mass, either on the fractured femur or on the uninjured femur. The muscles of the thigh showed a loss of 9% on the fractured side, but a gain of 12% on the uninjured side. The findings of a bone loss in the distal femur and proximal tibia of the fractured leg and in the proximal tibia of the healthy leg, but no cortical bone loss in the middle femur on any side 6 months after the fracture, indicate that the cancellous bone is more sensitive to osteopenia. Moreover, this bone loss is interpreted as mainly a posttraumatic effect, since we also found a decrease in bone mineral on the uninjured side, despite a gain in muscle volume on that side, an overuse which was not sufficient to counteract the posttraumatic effect on the bone of the uninjured side.

Bone Density

Intra-articular hyaluronan injections in the treatment of osteoarthritis of the knee: a randomised, double blind, placebo controlled multicentre trial. Hyaluronan Multicentre Trial Group.

OBJECTIVE: To assess the effects of intra-articular injections of hyaluronan on symptoms of knee osteoarthritis (OA). METHODS: Two hundred and forty patients with symptomatic, radiological knee OA were randomly assigned to treatment with weekly injections for five weeks with either 25 mg of high molecular weight hyaluronan or vehicle. Results were evaluated at weeks 1, 2, 3, 4, 5, 13, and 20 by visual analogue scales (pain, function, motion, activity), algofunctional index, and global evaluation by patient and investigator. Analysis was by "intention to treat', "per protocol', and area under the curve principles on unstratified patient groups and for patients stratified into four groups of equal size by age and baseline algofunctional index. RESULTS: No serious side effects were reported. At 20 weeks both treatment groups were improved compared with baseline, with no difference between unstratified groups treated with placebo or hyaluronan. Comparison of treatment groups stratified by age and baseline algofunctional index revealed a significant difference in favour of hyaluronan over placebo (pain, activity, algofunctional index, global evaluations by patient and investigator) for patients older than 60 years and with a baseline algofunctional index greater than 10. There was no clinically relevant difference between the two treatments for the other three stratified subgroups of younger age or fewer symptoms. Similar results were obtained by area under the curve, intention to treat, and per protocol analysis. CONCLUSIONS: Patients older than 60 years with knee osteoarthritis and with significant symptoms corresponding to an index of severity of knee disease of 10 or more, comprise the group most likely to benefit from treatment with intra-articular hyaluronan injections.

Adult

Cryotherapy after cruciate knee surgery. Skin, subcutaneous and articular temperatures in 8 patients.

We recorded temperature changes on the skin surface, subcutaneously and intra-articularly during cryotherapy after knee surgery by using Cryo-cuff compression dressings. Subcutaneous recordings on the contralateral knee were used as reference. 8 patients were examined. There was a reproducible decrease in skin temperature and subcutaneous temperature. Skin temperature had to be lowered to about 20 degrees C to obtain demonstrable intraarticular temperature changes.

Adolescent

Autologous blood transfusion in hip replacement. No effect on blood loss but less increase of plasminogen activator inhibitor in a randomized series of 80 patients.

80 patients underwent total hip replacement (THR) for primary coxarthrosis. In a randomized study, half of them donated 2 units of blood before operation. One unit was collected 4 weeks and one 2 weeks before the scheduled THR. All except 1 patient tolerated the predonations well. Total blood losses were similar in both groups. Additional bank blood was given in 7/38 in the predonation group, compared to 29/40 in the control group. Hemostatic parameters were studied in 10 consecutive patients in each group. Plasminogen activator inhibitor 1 (PAI-1), a possible risk parameter for thromboembolism, was significantly more increased postoperatively in the control group, which received only homologous blood. Platelet count, prothrombin complex, antithrombin III and von Willebrand factor antigen were significantly reduced and C reactive protein increased after surgery in both groups. We recommend predonation of 2 autologous units before a primary THR. In most cases, such predonation makes homologous blood transfusion unnecessary. The use of predonated blood causes no reduction of blood loss in THRs, but the increase in PAI-1 seen after homologous transfusions is avoided.

Aged

Air contamination during hip and knee arthroplasties. Horizontal laminar flow randomized vs. conventional ventilation.

In a randomized study 90 patients, operated on with a total hip or knee arthroplasty, were allocated to 1 of 3 different regimes, all including a reinforced single-use operating gown: (1) horizontal laminar flow ventilation and conventional clothes (cotton shirts and trousers) for all staff members, (2) horizontal laminar flow ventilation and occlusive garments (Klinidress) and (3) conventional ventilation and occlusive garments. Volumetric air sampling gave a low mean number of colony-forming units (< 10 cfu/m3) in the vicinity of the wound in all 3 groups. Laminar ventilation, with or without occlusive staff garments, resulted in less air contamination compared to conventional ventilation. During knee arthroplasty, the use of occlusive clothes in the laminar ventilation room, further reduced the number of airborne, bacteria-carrying particles to around 1 cfu/m3. No such reduction was seen during hip arthroplasty. We conclude that hip and knee arthroplasties can be performed in operating theaters with conventional ventilation when occlusive staff garments are used. However, laminar air flow ventilation in knee surgery, preferably in combination with occlusive garments, resulted in a substantially lower air contamination and should be preferred.

Aged

Reconstruction of old anterior cruciate ligament injuries. No difference between the Kennedy LAD-method and traditional patellar tendon graft in a prospective randomized study of 40 patients with 4-year follow-up.

In a prospective randomized study we investigated 40 patients with functional instability due to old anterior cruciate ligament tears by using two different techniques for reconstruction of the ligament. 20 patients were randomized to reconstruction with use of a traditional medial bone-patellar tendon graft and 20 patients to a half-thickness patellar tendon graft augmented with the Kennedy Ligament Augmentation Device (LAD). At follow-up after 4 years, both groups were still improved concerning function scores and arthrometry. The use of the Kennedy LAD method, however, gave no more subjective or objective benefits than did the traditional method.

Adolescent

Decrease in vertebral bone density after hip arthroplasty. A quantitative computed tomography study in 18 arthrosis cases.

We investigated the bone mineral density (BMD) of the lumbar vertebrae L1-3 with quantitative computed tomography (QCT) in 18 patients who had been operated on with hip arthroplasty because of unilateral arthrosis. In an earlier prospective study, we did not find any bone mineral changes in the femur or tibia after hip arthroplasty in spite of a large increase of the thigh muscle mass as a sign of a remobilization after the operation. The median BMD had decreased 5.3-8.4 percent in all the measured vertebrae after 6 months postoperatively. Because of the patients' improved walking ability after the operation, this decrease in cancellous vertebral BMD is interpreted as a sign of a post-traumatic osteopenia.

Aged

Biodegradable fixation of ankle fractures. A roentgen stereophotogrammetric study of 32 cases.

We performed a prospective randomized study comparing fixation with biodegradable polyglycolic acid (PGA) rods (n 15) or screws (n 17) in 32 selected displaced supination-eversion fractures. Immediate postoperative weight bearing in a walking cast was encouraged. An exact reconstruction of the ankle mortise was achieved in 26/32 ankles. Roentgen stereophotogrammetric analysis (RSA) revealed rather small movements in the ankle mortise during fracture healing. A better stability was achieved by using screws. After 6 months the clinical results did not differ. One case of sinus formation and one with local effusion occurred; both healed without impairing the clinical result. To compare the results with a nondegradable osteosynthesis technique, a reference group of supination-eversion fractures previously operated on with cerclage-wires, staples and pins was used. RSA showed better fracture stability with nondegradable fixation. The clinical results, however, did not differ.

Adult

Early postoperative ankle exercise. A study of postoperative lateral malleolar fractures.

Fifty-three patients with dislocated lateral malleolar fractures were randomly selected after operation for either active ankle movement and weight bearing in an orthosis or no ankle movement but weight bearing in a walking cast. At follow-up examinations after three, six, and 18 months, no differences were found between the groups except for a better linear analogue scale result at three months for the orthosis group. Active ankle movements do not improve the rehabilitation of surgically treated lateral malleolar fractures.

Adolescent

Trabecular patterns of the calcaneum as an index of osteoporosis. A comparison using gamma-absorptiometry.

Measurements of bone mineral content in the calcaneum were made by gamma-absorptiometry in 77 patients with ankle fractures treated by operation, and compared with the calcaneal osteoporosis index. The index was calculated from plain lateral radiographs of the calcaneum. The bone mineral measurements showed a wide range, but there was only a narrow range of the index with exclusively high values. There was a weak correlation between the calcaneal index and the bone mineral content in the injured ankles, but no or only a very poor correlation in the uninjured ankles. We also found no correlation between the decline in index and loss of mineral content in the injured ankles.

Absorptiometry, Photon

No effects of piroxicam on osteopenia and recovery after Colles' fracture. A randomized, double-blind, placebo-controlled, prospective trial.

In a randomized double-blind study involving 42 postmenopausal women with a displaced Colles' fracture, we investigated whether piroxicam, a nonsteroid anti-inflammatory drug, can reduce posttraumatic osteopenia and improve the rate of recovery. In an earlier study [3] we found a bone-sparing effect caused by piroxicam after external fixation of the rabbit hindleg. The patients were treated with a below-elbow paster slab for 4 weeks after the reduction. The bone mineral content of the forearm bones was measured with a single-photon absorptiometer 8 weeks after the fracture. There was a mean 7% bone mineral decrease in the radius and 5% in the ulna among the patients treated with piroxicam versus 10% in the radius and 7% in the ulna in the placebo group. However, this difference was not significant. Piroxicam did not decrease the rate of fracture healing. The patients who received piroxicam had significantly less pain during plaster treatment, but there was no difference in the rate of functional recovery between the groups.

Aged

Bone and muscle mass after hip rearthroplasty. Controlled CT study of 12 patients.

The cortical bone mineral density (BMD), bone volume, bone mass and muscle volume of the thigh and the cancellous BMD of the distal femur and proximal tibia were quantified by computed tomography (QCT) in 12 patients after hip rearthroplasty due to prosthetic loosening following arthroplasty for arthrosis. Both legs were scanned and the operated side was compared with the healthy side. A control group, 12 patients, had had unilateral hip arthroplasty without subsequent rearthroplasty. There was a 19 percent decrease in bone mass and 13 percent decrease in muscle volume in the middle femur, compared to the contralateral side, in the patients who had undergone rearthroplasty, and a reduction of 9 percent for the same variables in the control group. There was also a more marked osteopenia in the reoperated extremity in the distal femur and proximal tibia compared to the unoperated side.

Aged

Cruciate ligament prosthesis vs. augmentation. A randomized, prospective 5-year follow-up of 41 cases.

In a prospective study, 18 patients were randomized to a prosthesis and 23 patients to the Kennedy Ligament Augmentation Device (LAD) because of functional instability due to old anterior cruciate ligament injuries. The operations were performed with use of a modified over-the-top technique. At the last follow-up (5 years), postoperative improvements in scores were maintained for both groups, but LAD-reconstructed patients had better Lysholm and activity scores than the Goretex group. The achieved postoperative improvement in anterior stability (KT-1000) did not deteriorate for either of the groups during the 5-year follow-up. The Goretex patients had more effusion and pain and more secondary operations.

Anterior Cruciate Ligament