Minimum 3 years Follow-up Results of Metal on Metal Hip Resurfacing Arthroplasty

PURPOSE: To present the survival of consecutive patients with a minimum of three years follow-up after undergoing a metal-on-metal hip resurfacing arthroplasty. MATERIALS AND METHODS: Twenty hips from twenty patients (male: 16, female: 4) who underwent metal-on-metal resurfacing arthroplasty between October 2001 and April 2004 were followed up for at least 3 years. The mean patient age was 49 years (range 23~70), and the mean follow-up period was 56 months (range 36~84 months). A clinical evaluation was performed using the Harris hip score, and radiologic evaluation was performed regularly after surgery with plain radiographs. RESULTS: The mean Harris hip score improved from 46 points (range 73~32) preoperatively to 94 points at final follow-up. There were no cases of radiolucency or osteolysis around the stem or acetabular cup, and there was no migration of the acetabular or femoral component. The average femoral stem-shaft angle was 135degrees(range 121degrees- 139degrees), and at the final follow-up study, there was no change of the femoral stem. CONCLUSION: In the short-term, metal-on-metal resurfacing arthroplasty performed on the basis of bone quality and patient selection, showed excellent clinical and radiological results. Hip resurfacing is an attractive option for young patients fearing a potentially difficult future revision or for more active patients with hip disease.

The Effects of Foot Pump on Prevention of Deep Vein Thrombosis Following Total Knee Arthroplasty

PURPOSE: To compare the efficacy and availability of foot pump and active ankle exercise for preventing deep vein thrombosis after total knee arthroplasty with hemodynamic evaluation using a color doppler duplex ultrasonography. MATERIALS AND METHODS: Thirty-six patients who underwent total knee arthroplasty between Oct. 2005 and Apr. 2006 were enrolled in this study. Retrospective analysis of 36 patients(Group 1 - foot pump after TKA, 18; Group 2-passive ankle exercise, 18) was conducted and all patients underwent color doppler duplex ultrasonography preoperatively and postoperative 7 to 14 days at femoral, popliteal and calf vein and the hemodynamic status was assessed. RESULTS: The mean baseline velocity was decreased postoperatively in both group, at all veins, but the mean peak velocity was increased only in Group. In Group 1, mean flow ratio was increased, but in Group 2, mean flow ratio was decreased except femoral vein. There were significant differences between Group 1 and Group 2(p<0.05). CONCLUSION: This study demonstrated that foot pump may be more effective than active ankle exercise in preventing postoperative deep vein thrombosis due to more increased venous flow rate and foot pump may be more compliable than active ankle exercise due to less painful, more convenient, so foot pump can be one of the available method for preventing DVT after total knee arthroplasty.

Analysis of Affecting Factors of Fixation Failure of Femoral Neck Fractures Using Internal Fixation

PURPOSE: To evaluate the factors which influence on the fixation failure after internal fixation using multiple cannulated screws in the patients with femoral neck fracture. MATERIALS AND METHODS: Ninty-six patients (male: 63, female: 33) who underwent closed reduction and internal fixation of femoral neck fracture between Feb. 1994 and Jun. 2002 with use of multiple cannulated screws. The mean age was 68 years (17~90) and mean follow-up period was average 50 months (36 months~6 years). The fixation failure was defined by change in fracture position above 10 mm, change in each screws position above 5%, backing above 20 mm, or perforation of the head, respectively. They were evaluated with the age, gender, fracture type, accuracy of reduction, placement of screws, posterior comminution and also studied the risk factors which influenced nonunion and the development of avascular necrosis. RESULTS: Twenty-four patients out of 96 patients had radiographic signs of fixation failure. The incidence of nonunion in the fixation failure group was 41% (10/24) and AVN was 33% (8/24). There were statistically significant correlations between fixation failure and nonunion and that posterior comminution, poor reduction and improper placement of the screws were the major factors contributing to nonunion. CONCLUSION: In case of femoral neck fracture of internal fixation using multiple cannulated screws, posterior comminution, poor reduction and improper placement of the screws were the major factors contributing to nonunion and fixation failure.

Patellar Nonresurfacing in Total Knee Arthroplasty

PURPOSE: The management of the patella in total knee arthroplasty is still controversy. The purpose of this study was to evaluate clinical and radiological results after total knee arthroplasty without patellar resurfacing. MATERIALS AND METHODS: We retrospective evaluated the nonresurfaced patella in 50 Knees(45 patients) at an average of 65.5 months after total knee arthroplasty(Duracon (R), Howmedica, Rutherford, NJ). Patients were diagnosed as osteoarthritis in 45 and rheumatoid arthritis in 3 and the others were osteonecrosis and evaluated using the knee society knee score, functional knee score and modified patellar score. RESULTS: The mean preoperative knee society knee score in osteoarthritis and rheumatoid arthritis were 58.2 and 36.7 points, and functional score were 35.8 and 34 points. The mean postoperative knee society knee score in osteoarthritis and rheumatoid arthritis were 94.5 and 91.2 points, and functional score were 73.2 and 81 points and the mean modified patellar score was 28.5 points, and 26 cases(52%) were excellent(30-35 points), 18 cases(36%) were good(25-29 points) and 6 cases(12%) were fair(20-24 points). There were no patella-associated complications and in 8 cases(16%) of anterior knee pain, which resolved by a postoperative 4.1 months with conservative treatment. CONCLUSION: Total knee arthroplasty with patelloplasty, without patellar resurfacing , provided satisfactory results without significant problems, and can avoid the patellar complications. But long term radiological and clinical follow-up is recommended.