Immediate weight bearing after uncemented total hip arthroplasty with an anteverted stem: a prospective randomized comparison using radiostereometry.

Background: In uncemented total hip arthroplasty with hydroxyapatite coating, early weight bearing is frequently practiced but there is still not much evidence to support this recommendation.

Method: In a prospective randomized study we evaluated the effect of partial and full weight bearing after cementless total hip arthroplasty (ABG; Stryker-Howmedica) using radiostereometric analysis (RSA). Between February 1996 and February 2000, 43 consecutive patients (mean age 53 (41-63) years, 23 women) with hip osteoarthrosis received an uncemented and hydroxyapatite-coated prosthesis with an anteverted stem.

Pharmacokinetic profile of the oral direct thrombin inhibitor dabigatran etexilate in healthy volunteers and patients undergoing total hip replacement.

Dabigatran etexilate is an oral low-molecular-weight direct thrombin inhibitor. Following oral administration, dabigatran etexilate is rapidly converted to its active form, dabigatran. The authors investigated the absorption, distribution, and elimination of a single 150-mg dose capsule formulation of dabigatran etexilate in healthy volunteers and patients undergoing total hip replacement.

A new oral direct thrombin inhibitor, dabigatran etexilate, compared with enoxaparin for prevention of thromboembolic events following total hip or knee replacement: the BISTRO II randomized trial.

Background: Dabigatran etexilate is an oral direct thrombin inhibitor undergoing evaluation for the prevention of venous thromboembolism (VTE) following orthopedic surgery.

Methods: In a multicenter, parallel-group, double-blind study, 1973 patients undergoing total hip or knee replacement were randomized to 6-10 days of oral dabigatran etexilate (50, 150 mg twice daily, 300 mg once daily, 225 mg twice daily), starting 1-4 h after surgery, or subcutaneous enoxaparin (40 mg once daily) starting 12 h prior to surgery. The primary efficacy outcome was the incidence of VTE (detected by bilateral venography or symptomatic events) during treatment.

Dose escalating safety study of a new oral direct thrombin inhibitor, dabigatran etexilate, in patients undergoing total hip replacement: BISTRO I.

Background: Dabigatran etexilate (BIBR 1048) is an oral direct thrombin inhibitor undergoing evaluation for the prevention of venous thromboembolism (VTE) following total hip replacement. Following oral administration, dabigatran etexilate is rapidly converted to its active form dabigatran (BIBR 953 ZW).

Objectives: To determine the safe therapeutic range of dabigatran etexilate following total hip replacement.

Prophylaxis of venous thromboembolism with subcutaneous melagatran in total hip or total knee replacement: results from Phase II studies.

The first clinical studies evaluating the safety and efficacy of melagatran, a novel, direct thrombin inhibitor, given subcutaneously as prophylaxis for venous thromboembolism (VTE) following total hip (THR) or total knee replacement (TKR) are reported. In Study I, 66 patients received subcutaneous melagatran (1.5-6 mg bid) in a poloxamer depot formulation, and in Study II, 104 patients received subcutaneous melagatran (2-4 mg bid) in saline or as a depot formulation in cyclodextrin.

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.

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.

Prognosis of total hip replacement in Sweden. Follow-up of 92,675 operations performed 1978-1990.

A prospective, national multi-center study of all reoperations after total hip replacement (THR) was started by the Swedish Orthopedic Association in 1979. The material comprises all THR performed in Sweden, presently more than 10,000 yearly or 130 THR per 100,000 inhabitants; uncemented implants have been used in less than 2 percent. The main reasons for revision have been aseptic loosening 79 percent, infection 10 percent, technical error 6 percent, and dislocation 2 percent.

Incidence of dislocation after hip arthroplasty. Comparison of different registration methods in 408 cases.

We studied four different methods of registration of dislocations after total hip arthroplasty (THA) carried out at Malmö General Hospital during 1979-1988. Established registers failed to incorporate more than half of the dislocations and approximately one third of the patients, compared with a manual retrospective review of the original operating cords and the patient files. In 22 percent of the cases the first dislocation occurred more than one year postoperatively.

Multicenter clinical trials and their value in assessing total joint arthroplasty.

Multicenter clinical trials (MCT) have an important role in the assessment of total joint arthroplasty. The primary reason for such MCT is the need to have access to a large number of patients. In Sweden, failure after total hip arthroplasty has been recorded prospectively since 1979.

How far does prophylaxis against infection in total joint replacement offset its cost?

Selection of a cost effective method of prophylaxis against infection for patients undergoing total joint replacement was shown to depend on the number of arthroplasties performed each year at individual hospitals. When 100 arthroplasties were performed each year the prophylactic use of systemic antibiotics minimised the total costs of the department--that is, the combined costs of prophylaxis and reoperation for deep sepsis. Some departments also used local antibiotic prophylaxis in the form of polymethylmethacrylate cement impregnated with gentamicin or a combination of systemic and local prophylaxis at almost as low a total cost and with comparable effect.

Revision total hip arthroplasty in patients younger than 55 years old. Clinical and radiologic results after 4 years.

Since 1979, all revision total hip arthroplasties performed in Sweden have been entered into a prospective multicenter study. Between 1979 and 1982, 65 patients (67 hips) younger than 55 years old required revision arthroplasty because of aseptic loosening. These patients were followed clinically and radiographically for 2-6 years (mean, 4 years).