Modular Stems: Advantages and Current Role in Primary Total Hip Arthroplasty / 대한고관절학회지

Using modular femoral stems in total hip arthroplasty enables surgeons to make fine adjustments to individual joints and offers intraoperative flexibility. The concept of modularity has been developed in numerous shapes, resulting in a vast range of options. Among them, the greatest achievement has been made for prostheses with modular proximal sleeves. The use of these implants has resulted in excellent mid- to long-term results in a number of cases. Although the use of tapered stems with a broaching technique is gaining popularity in straightforward primary surgeries, modular femoral implants are still associated with a number of potential challenges (e.g., developmental dysplasia of the hip, infection sequelae, and skeletal dysplasia). Based on published results, it is advisable to consider it as an option for complicated cases where the proximal femur is severely deformed.

Result of Modular Necks in Primary Total Hip Arthroplasty with a Average Follow-up of Four Years / 대한고관절학회지

PURPOSE: This study aimed to investigate the outcomes of modular neck-utilization in primary total hip arthroplasty (THA). MATERIALS AND METHODS: Thirty patients (34 hips) who had modular stem THA between April 2011 and January 2013 were evaluated. There were 19 men and 11 women with a mean age of 61.2 years at the time of surgery. There were 20 cases of osteonecrosis of femoral head, 7 cases of osteoarthritis, 6 cases of femur neck fracture, and 1 case of rheumatoid arthritis. No patients presented with anatomical deformity of hip. Patients were operated on using a modified Watson-Jones anterolateral approach. All patients underwent clinical and radiological follow-up at 6 weeks, 3, 6, and 12 months, and every year postoperatively. The mean duration of follow-up was 48.2 months (range, 39 to 59 months). RESULTS: The average Harris hip score improved from 63.7 to 88.1 at the final follow-up. Radiographically, mean acetabular cup inclination was 45.3°(range, 36°-61°) and anteversion was 21.7°(range, 11°-29°). All were neutral-positioned stems except 5 which were varus-positioned stems. In only 3 cases (8.8%), varus or valgus necks were required. A case of linear femoral fracture occurred intraoperatively and 1 case of dislocation occurred at postoperative 2 weeks. No complications at modular junction were occurred. CONCLUSION: Our study shows that the use of modular necks had favorable clinical and radiographic results. This suggests that the use of modular neck in primary THA without anatomical deformity is safe at a follow-up of 39 months.

Femoral Revisional Arthroplasty using Proximal Modular Femoral Stem: Short Term Follow Up / 대한정형외과학회잡지

PURPOSE: The aim of this study was to evaluate the clinical and radiological results of a cementless femoral revision using a proximal modular stem for 38 hips (38 patients) with femoral osteolysis after primary total hip arthroplasty. MATERIALS AND METHODS: Thirty-eight hips (38 patients), which had been revised with a proximal modular femoral component were included in this study. All 38 patients were treated using the posterolateral approach. The minimum follow-up period was 2 years. The stem stability was checked radiographically and the hip function was evaluated using the Harris hip score. RESULTS: Thirty-eight patients were follow-up for an average of 3.2 years. The Harris hip score was improved from an average of 49 points to an average of 84 points. Radiographically, satisfactory results were noted in 20 (52.6%) of the 38 hips at the latest follow-up. Complications were encountered in 8 hips (21%). An intraoperative femoral crack were encountered in 6 hips; circumferential wiring in 4 hips, and screw fixation in 2 hips. All 6 femoral cracks were healed within 3 months. Postoperative hip dislocation occurred in 2 hips (5.3%), which was successfully managed by manual reduction and abduction brace for 6 weeks. CONCLUSION: The short or midterm clinical and radiological results of cementless femoral revision using proximal modular stem for the hips with femoral osteolysis were satisfactoy. However it is believed that a longer follow-up is needed.

Total Hip Revision with Proximal Modular Femoral Stem / 대한정형외과학회잡지

PURPOSE: To evaluate the results of femoral component revision with proximal modular prosthesis in 32 hips. MATERIALS AND METHODS: Thirty-two hips of thirty patients, which were revised with proximal modular femoral component due to aseptic loosening, were investigated. These patients were followed radiologically and clinically at least for two years. RESULTS: These patients were followed for an average of 2.8 years. Complications included four intraoperative femoral fractures (three at proximal, one at distal), two progressive subsidence, one infection, and one non-union and one fibrous union of the greater trochanter. Of the 32 hips, three hips were re-revised due to progressive subsidence in two and recurrent dislocation in one. Acute postoperative infection developed in one patient, who suffered from diabetes mellitus. Radiographically, satisfactory results were noted in 27 (84.7%) of 32 hips at the latest follow-up. Harris hip score was improved from an average of 47 points to an average of 93 points. CONCLUSION: This study provides encouraging results in femoral component revision with proximal modular prosthesis.

Postoperative Periprosthetic Femoral Fracture Associated with Loosening of the Femoral Prosthesis / 대한정형외과학회잡지

PURPOSE: To evaluate the results of the treatment of postoperative periprosthetic fracture of the femur associated with loosening of the femoral prosthesis, which is treated by cementless proximal modular stem without bone graft. MATERIALS AND METHODS: Nine postoperative periprosthetic femoral fractures were classified by Duncan's method. Seven patients were in the B2 group and two were in the B3. All were managed with proximal modular fluted stem. Results were evaluated on the basis of bone union and Harris hip scores at 2.5 years follow-up. RESULTS: All were successfully united at 7.5 weeks after revision. The mean Harris hip scores were 45.7 preoperatively and 92 at final follow-up. One patient who suffered from diabetes previously showed deep infection. CONCLUSION: Postoperative periprosthetic fractures were successfully managed with proximal modular long fluted femoral stem without bone graft.