Biomedical subjects

H Fredin

Publications and source records attributed to H Fredin.

At least 19 recordsLinked to original sources

PubMed2001

Blood conservation with tranexamic acid in total hip arthroplasty: a randomized, double-blind study in 40 primary operations.

We performed a randomized, double-blind study on the effect of tranexamic acid on blood loss and blood transfusions in 40 primary total hip arthroplasties. Tranexamic acid, 10 mg/kg body weight, or placebo, was given intravenously just before the operation. Blood loss during the operation and postoperatively into the drains was recorded, as also were blood hemoglobin concentrations. Ultrasound examination 1 week postoperatively was done to estimate the blood loss due to remaining hematomas. Total (operation + drain) blood loss was 0.76 (95 CI 0.63-0.89) L in the tranexamic acid group as compared to 1.0 (CI 0.81-1.2) L in the placebo group (p = 0.03). The number of blood transfusions during the day of operation was 2 vs. 10 (p = 0.07) and the total number during the hospital stay was 5 vs. 13 (p = 0.2). 1 patient in each group had a pulmonary embolism.

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PubMed2000

Tranexamic acid, given at the end of the operation, does not reduce postoperative blood loss in hip arthroplasty.

We performed a randomized double-blind study on the effect of tranexamic acid on postoperative blood loss and blood transfusions in 39 primary THR operations. Tranexamic acid was given at the end of the operation and 3 hours later. Ultrasound examination 1 week later was performed to measure the occurrence of deep hematomas. In contrast to previous findings in knee arthroplasty, the administration of tranexamic acid failed to give a significant reduction in the postoperative blood loss. This lack of effect was possibly related to the fact that the drug was administered too late. In 11 of the 20 patients receiving tranexamic acid, blood transfusion was not necessary, this being the case in 4/19 in the placebo group (p = 0.05). The occurrence of postoperative deep venous thromboses was similar in the tranexamic acid and placebo groups.

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PubMed1999

Muscular and neurologic function in patients with recurrent dislocation after total hip arthroplasty: a matched controlled study of 65 patients using dual-energy X-ray absorptiometry and postural stability tests.

Twenty-two patients with recurrent dislocation after primary total hip arthroplasty (THA) were compared with 43 randomly selected, stratified THA patients without dislocation with regard to radiographic cup position; body composition of bone, fat, and muscle (lean body mass) as determined by dual-energy x-ray absorptiometry; strength in abduction and adduction; range of motion; balance; and vibration sense. Balance and sensitivity to vibration were impaired in the patients with dislocation. No differences were found in any other variables except a subset of tall men in the dislocation group.

Absorptiometry, Photon↗

PubMed1997

The effect of tranexamic acid on local and plasma fibrinolysis during total knee arthroplasty.

The aim of the present study was to investigate aspects of coagulation and fibrinolysis during knee arthroplasties in order to find out. 1. whether an increased fibrinolysis is correlated to an increased blood loss 2. whether there is a difference in markers for coagulation and fibrinolysis in peripheral venous blood compared to those in blood from the wounds 3. whether the administration of tranexamic acid modifies the fibrinolytic response. Twenty-four patients were included. Twelve patients were given tranexamic acid intravenously at the end of the operation. The dose was repeated three hours later. The other 12 patients were given an equivalent amount of placebo. The administration was randomised and double-blind. Levels of prothrombin fragments 1 + 2, D-dimers, plasminogen, alpha 2-antiplasmin, tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAI-1) in venous blood were investigated just before the operation, at the end of the operation and three hours later. At the end of the operation blood for analysis was also drawn from the wound. Coagulation and fibrinolysis was activated during and after surgery. The activation was significantly higher in blood from the wounds than in peripheral venous blood. We found no direct correlation between the degree of fibrinolysis and blood loss. The administration of tranexamic acid reduced fibrinolysis in the wounds but not in peripheral venous blood. The postoperative blood loss was reduced by half.

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PubMed1997

The prognosis and treatment of dislocated total hip arthroplasties with a 22 mm head.

We studied the risk of recurrent dislocation in 121 primary and 39 revision Charnley or Charnley hybrid total hip arthroplasties which had been treated for a primary dislocation between 1979 and 1995. Only 35% of these hips had no further dislocation or a revision for instability within one year. The rates of survival gradually declined with time or if a second, third or fourth dislocation occurred. The risk of recurrence was greater in men, but was not related to age, diagnosis, time of the first dislocation or whether the index operation had been a primary or a revision procedure. Operative treatment included 15 reoperations leaving intact components, 50 revisions, and permanent removal of the femoral stem in seven patients. The operation was successful in four patients with reoperations and in 36 who had an exchange procedure within two years. Treatment was successful in 35 of 49 hips in which it was possible to correct a technical error compared with 5 out of 16 hips in which malposition of the components was not seen (p = 0.007).

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PubMed1997

Low- or high-vacuum drains in hip arthroplasty? A randomized study of 73 patients.

We compared the effect of low-vacuum and high-vacuum drains on blood loss and blood transfusions in a randomized study of 73 patients undergoing primary hip arthroplasties. During the first postoperative hour, the high-vacuum drains evacuated more blood than the low-vacuum ones, median 135 and 35 mL (p < 0.001). After that, the rate of blood loss into the drains was approximately the same. Median blood losses into the drains after 24 hours were 570 mL in the high-vacuum group and 480 mL in the low-vacuum group (p = 0.03). Corresponding values after 48 hours were 785 mL and 585 mL (p = 0.002). The hemoglobin concentration in the drain fluid during the second postoperative day was lower in the high-vacuum group, indicating a more serous discharge. Our findings indicate that drains should be removed within 24 hours. High-vacuum drains evacuate more blood initially but may cause more damage to the tissues, especially if they are left for more than 24 hours. We found no significant difference in postoperative hemoglobin decrease or in the number of blood transfusions and wound complications in the 2 groups.

Aged↗

PubMed1997

The post-discharge prophylactic management of the orthopedic patient with low-molecular-weight heparin: enoxaparin.

This prospective, double-blind trial was performed to determine whether 4 weeks' prophylaxis with enoxaparin after total hip replacement (THR) is more effective in protecting against deep vein thrombosis (DVT) than prophylaxis during hospitalization. Two hundred sixty-two patients undergoing THR were given enoxaparin 40 mg once daily during hospitalization (9 +/- 2 days) before being randomized at discharge to continue enoxaparin (N = 131) or receive placebo (N = 131) for a total of 1 month (30 +/- 4 days). According to intention-to-treat analysis, 43 DVT and 2 pulmonary emboli (PE) occurred in the placebo group (34.4%) versus 21 DVT and no PE in the enoxaparin group (P < 0.001). The reduction in proximal DVT was also significant (21.4 vs 6.1%; P < 0.001). No major bleeding complications developed. Prophylaxis with enoxaparin for one month significantly reduces venous thromboembolic disease in patients undergoing THR compared to conventional prophylaxis during hospitalization.

Adult↗

PubMed1997

Female gender and resistance to activated protein C (FV:Q506) as potential risk factors for thrombosis after elective hip arthroplasty.

Resistance to activated protein C (APC) caused by the R506Q mutation in factor V is the most common inherited risk factor for venous thrombosis. To elucidate whether APC-resistance is a risk factor for venous thrombosis after elective total hip replacement, the association between APC-resistance (presence of FV:Q506 allele) and postoperative thrombosis was investigated in patients (n = 198) randomised to received short (during hospitalisation, n = 100) or prolonged prophylaxis (three weeks after hospitalisation, n = 98) with low molecular weight heparin (LMWH). Among APC-resistant individuals receiving short prophylaxis, 7/10 developed thrombosis as compared to 2/12 receiving long prophylaxis (p <0.0179). Odds ratio for association between APC-resistance and thrombosis in the short prophylaxis group was 4.2 (CI 95% 1.02-17.5) (p <0.0465). Among those receiving prolonged prophylaxis, there was no increased incidence of thrombosis associated with APC-resistance. Two unexpected observations were made. One was that APC-resistance was much more common in women (19/109) than in men (3/89) (p <0.001). The other was that even women without APC-resistance were much more thrombosis-prone than men. Thus, 24/48 of women with normal FV genotype and short prophylaxis developed thrombosis vs 8/42 among men, p = 0.002. The increased risk of thrombosis associated with female gender and APC-resistance was neutralised by the prolonged treatment. In conclusion, among patients receiving short prophylaxis, female gender was found to be a strong risk factor for venous thrombosis. Even though APC-resistance appeared to be a risk factor for postoperative thrombosis, the uneven distribution of APC-resistance between men and women, taken together with the increased risk of thrombosis among women, precluded valid conclusions to be drawn about the association between APC-resistance and an increased risk of thrombosis. Our results suggest that prolonged prophylaxis with LMWH after hip surgery is more important for women than for men.

Adult↗

PubMed1996

Low-molecular-weight heparin (enoxaparin) as prophylaxis against venous thromboembolism after total hip replacement.

BACKGROUND: The risk of venous thromboembolism in patients undergoing total hip replacement is known to be high. However, the optimal duration of prophylaxis with anticoagulant agents after this procedure is unknown. We sought to determine whether one month of anticoagulant therapy with the low-molecular-weight heparin enoxaparin is more effective than enoxaparin therapy given only during the hospitalization for surgery. METHODS: Two hundred sixty-two patients undergoing total hip replacement received enoxaparin during their hospitalizations (average stay, 10 to 11 days). They were then randomly assigned to receive enoxaparin or placebo (131 patients each). Blinded outpatient therapy (or placebo) was continued long enough that the total treatment period, inpatient plus outpatient, was one month for each patient. Bilateral ascending phlebography was performed 19 to 23 days after discharge, with deep-vein thrombosis as the primary end point. Distal and proximal thrombosis, pulmonary embolism, and hemorrhage were also recorded, as were deaths. RESULTS: Venography was adequate in 116 patients in the placebo group and 117 in the enoxaparin group. We observed 43 episodes of deep-vein thrombosis and 2 episodes of pulmonary embolism in the placebo group, but only 21 episodes of deep-vein thrombosis and no episodes of pulmonary embolism in the enoxaparin group (incidence of thromboembolism, 39 percent and 18 percent, respectively; P<0.001). The difference in the incidence of proximal deep-vein thrombosis was also significant (24 percent and 7 percent in the placebo and enoxaparin groups, respectively; P<0.001). Six enoxaparin groups, respectively; P<0.001). Six patients in the enoxaparin group and one patient in the placebo group had hematomas at their injection sites. No patients died or had major complications. CONCLUSIONS: There were significantly fewer venous thromboembolic complications in patients undergoing elective hip replacement when prophylaxis with enoxaparin was given for a total of one month, rather than only during the hospitalization.

Adult↗

PubMed1996

Primary anterior dislocation of the shoulder in young patients. A ten-year prospective study.

Two hundred and forty-five patients who had had 247 primary anterior dislocations of the shoulder were followed for ten years in a multicenter study at twenty-seven Swedish hospitals. The ages of the patients at the time of the dislocation ranged from twelve to forty years. The patients were assigned to one of three treatment groups: immobilization with the arm tied with a bandage to the torso for three to four weeks after reduction of the dislocation; use of a sling, which was discontinued after the patient was comfortable; or immobilization for various durations. At the ten-year follow-up evaluation, no additional dislocation had occurred in 129 shoulders (52 per cent). Recurrent dislocation necessitating operative treatment had developed in fifty-eight shoulders (23 per cent): thirty-four (34 per cent) of the ninety-nine shoulders in patients who were twelve to twenty-two years old, sixteen (28 per cent) of the fifty-seven shoulders in patients who were twenty-three to twenty-nine years old, and eight (9 per cent) of the ninety-one shoulders in patients who were thirty to forty years old. Twenty-four (22 per cent) of the shoulders that had had at least two recurrences during the first two or five years seemed to have stabilized spontaneously without operative intervention at ten years. Dislocation of the contralateral shoulder occurred in association with sixteen (16 per cent) of the ninety-nine shoulders in patients who were twelve to twenty-two years old, twelve (21 per cent) of the fifty-seven shoulders in patients who were twenty-three to twenty-nine years old, and only three (3 per cent) of the ninety-one shoulders in patients who were thirty to forty years old. The type and duration of the initial treatment had no effect on the rate of recurrence. Radiographs, made for 185 shoulders at the time of the primary dislocation, demonstrated an evident Hermodsson (Hill-Sachs) lesion in ninety-nine shoulders (54 per cent); this finding was associated with a significantly worse prognosis with regard to recurrence than was no evident lesion (p < 0.04). Radiographs made for 208 shoulders at the ten-year follow-up examination were evaluated for post-dislocation arthropathy. Twenty-three shoulders (11 per cent) had mild arthropathy and eighteen (9 per cent) had moderate or severe arthropathy. Some of the shoulders that had arthropathy had had no recurrence.

Adolescent↗

PubMed1996

Social function after cervical hip fracture. A comparison of hook-pins and total hip replacement in 47 patients.

47 patients with a cervical hip fracture Garden 3 or 4 and fully ambulatory before the fracture, were randomized to either fixation with Hansson hook-pins (24 patients, median age 79 years) or to a Charnley hip replacement (23 patients, median age 80 years). The patients were followed for 2 years. Social function was evaluated using a standard questionnaire. There were no postoperative deaths and no significant differences in hospital stay. 9/24 patients treated with hook-pins developed healing complications and 2 dislocations occurred in the THR group. After 1 and 2 years, fewer patients treated with hip replacement used outdoor walking aids; they were also more likely to do their own shopping. Hip replacement is a good choice when treating healthy older people with displaced cervical hip fractures, when primary mortality is expected to be low and the risk of healing complications after nailing is high.

Activities of Daily Living↗

PubMed1996

Fibrinolytic inhibition with tranexamic acid reduces blood loss and blood transfusion after knee arthroplasty: a prospective, randomised, double-blind study of 86 patients.

We investigated the effect of a fibrinolytic inhibitor, tranexamic acid, on blood loss and blood transfusion in knee arthroplasty by a randomised, double-blind study of 86 patients. A dose of 10 mg/kg body-weight of either tranexamic acid or placebo was given intravenously shortly before the release of the tourniquet, and repeated three hours later. The mean total blood loss was 730 +/- 280 ml in the tranexamic acid group as against 1410 +/- 480 ml in the placebo group (p < 0.001). Both the number of patients receiving blood transfusion and the number of blood units transfused were reduced to one-third in the treated group, and mean postoperative Hb concentrations were significantly higher after prophylaxis. The number of thromboembolic complications was the same in both groups. Tranexamic acid should be given prophylactically in order to be effective.

Aged↗

PubMed1996

Surgical experience related to dislocations after total hip arthroplasty.

We studied the effect of surgical experience on the dislocation rate after 4230 primary total hip arthroplasties (THAs) all performed using the posterior approach at three orthopaedic centres at major county hospitals. There were 129 postoperative (3%) dislocations. Twice the number of dislocations were registered for inexperienced surgeons as for their more experienced colleagues. This frequency of dislocation levelled off with increasing numbers of operations and remained constant after approximately 30. For every ten primary THAs performed annually, the risk of dislocation decreased by 50%.

Clinical Competence↗

PubMed1996

The efficacy and safety of blood reinfusion in avoiding homologous transfusion after total knee arthroplasty.

This study examined the efficacy of the Solcotrans (Solco Basle Ltd, United Kingdom) drainage system in the retransfusion of filtered drainage blood in total knee arthroplasty (TKA) patients. A study group of 58 TKA patients who received autologous blood reinsfusion was compared with a control group of 59 TKA patients who did not receive autologous blood reinfusion. Results showed that the number of patients who needed homologous blood transfusion was reduced from 78% in the control group to 34% in the study group. The complication rate was low. We conclude that postoperative retransfusion of small to moderate volumes of drainage blood can be used safely in clinical practice to decrease the need for homologous transfusion.

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PubMed1996

Dislocations and the femoral head size in primary total hip arthroplasty.

The dislocation rate of 3197 Charnley prostheses with 22 mm head in which the surgery was done between 1979 and 1991 in 2 orthopaedic centers was compared with that of 2875 Lubinus prostheses with 32 mm head in which the surgery was done between 1980 to 1991 in 3 other centers. A 1-year followup showed an equal rate of dislocation (2.4%-2.5%) in the 2 groups and included 75% of the 201 dislocated hips. Almost all of the late dislocations occurred with the Charnley prosthesis, resulting in a total dislocation rate of 3.7% compared with 2.9% with the Lubinus prosthesis. Regardless of the type of prosthesis used, there was a higher risk of dislocation in patients with nonhealed hip fractures and in arthroplasties performed by less experienced surgeons. When these 2 variables were removed, the small femoral head was not associated with an increased risk of dislocation. However, there were 77 of 118 (65%) recurrent dislocations in the Charnley group, compared with 37 of 83 (45%) in the Lubinus group, and the relative risk of a dislocated hip arthroplasty becoming recurrent increased by 2.3 times if the small femoral head was used. The number of reoperations also were doubled in this group. Almost 4 times as many dislocations were documented within 2 weeks after surgery after any type of prosthesis inserted through a posterior approach compared with the transtrochanteric approach, but there was no increase in rate of recurrence or revision.

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PubMed1995

Influence of surgical approach on dislocations after Charnley hip arthroplasty.

Dislocations occurring in 3,199 Charnley total hip arthroplasties in two orthopaedic centers between 1979 and 1991 performed by either the transtrochanteric or posterior approach were studied. The incidence of dislocation within 2 years of surgery (2.8%), as well as the overall frequency (3.4%), did not differ between the two centers. Regardless of approach, there was a higher risk of dislocations for patients with osteoarthrosis. A logistic regression analysis, reflecting the differences in preoperative hip diagnoses and sex, indicated that the dislocation rate was not influenced by the surgical approach. More early dislocations were documented after the posterior approach, but without increases in the rates of recurrence or revision. Arthroplasties performed by less experienced surgeons through the posterior approach resulted in more dislocations.

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PubMed1995

Patient characteristics in dislocations after primary total hip arthroplasty. 60 patients compared with a control group.

To determine patient-related risk factors for dislocation after a primary Charnley hip arthroplasty, we compared 60 patients with at least one dislocation to a randomly selected group of 118 patients with no dislocation. Apart from an increased mortality rate among the patients with a dislocated prosthesis, we could not relate dislocations to any somatic and psychiatric disorder or to the use of any particular group of pharmaceuticals. However, suspicion of alcohol abuse was commoner among men in the dislocated group.

Adult↗

PubMed1995

Does tranexamic acid reduce blood loss in knee arthroplasty?

In a retrospective study of 179 total knee arthroplasties, 70 patients received tranexamic acid (Cyklokapron, Kabi Pharmacia, Uppsala, Sweden) before the tourniquet was released to reduce postoperative blood loss. A group of 109 patients who underwent surgery before this treatment was introduced served as controls. Multiple regression analysis showed that the average postoperative blood loss was 340 mL less in treated patients compared with controls. Blood transfusions were reduced from 2 to 0 units (median values). Complications did not differ between the two groups apart from the number of postoperative hematomas.

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