Femoral Revision with the Wagner SL Revision Stem / 대한정형외과학회잡지

PURPOSE: To evaluate the results of revision total hip arthroplasty using a Wagner SL revision stem. MATERIALS AND METHODS: This study reviewed 56 revisions of the femoral component performed using a Wagner stem in 55 patients between 1992 and 2001. The mean age of the patients at the time of the revision was 50 years. The mean follow up duration was 8.4 years (range, 5 to 12.5 years). The indication for revision was aseptic loosening in fifty-two hips, septic loosening in two and periprosthetic fractures in two. The pre-revisional femoral defects were classified according to the Paprosky classification system. A clinical evaluation and radiological assessment were performed. RESULTS: The mean Harris hip score improved from 47 points preoperatively to 87 points at the latest follow-up. There were 5, 20, 22 and 9 hips of type I, II, IIIA and IIIB according to the Paprosky classification system. Fifty two hips (93%) showed stable stems at the latest follow-up radiographs. The mean vertical subsidence of the stem was 6.2 mm (range, 0 to 21 mm). Severe progressive vertical subsidence in three hips and an infection in one occurred requiring repeat revision. CONCLUSION: For severe proximal femoral bone loss, the conical femoral revision stem with a fully grit-blasted surface produced satisfactory results with distal press-fit fixation. We can expect a decrease in the rate of mechanical failure rate of the stem by reducing the subsidence derived from the stem design itself.

Total Knee Arthroplasty with Anteroposterior Glide Low Contact Stress(R) : Minimum 5-Year Follow-up Results / 대한정형외과학회잡지

PURPOSE: We report the minimum 5-year follow-up results of total knee arthroplasty with anteroposterior glide LCS(R) CompleteTM. MATERIALS AND METHODS: From June 1999 to June 2000, we performed sixty-two primary total knee replacements with the anteroposterior glide LCS(R) CompleteTM. Fifty-eight cases were followed-up for a minimum of 5 years. The posterior cruciate ligaments were preserved in all the cases. RESULTS: The mean Hospital for Special Surgery Knee Score increased from 62.9 points preoperatively to 88.6 points at the most recent follow-up. The mean knee score of the American Knee Society increased from 56.9 points preoperatively to 90.8 points and the functional score increased from 39.8 points to 76.8 points at the most recent follow-up. The mean flexion contracture decreased from 11.5 degrees preoperatively to 1.6 degrees and the range of motion with flexion increased from 103.5 degrees to 112.2 degrees. There was no loosening, osteolysis, or measurable polyethylene wear in any of the cases. We experienced dislocation of the polyethylene liner and guide arm in one case, but there was no revision surgery performed due to loosening or infection. CONCLUSION: Anteroposterior glide LCS(R) CompleteTM demonstrated excellent clinical and radiological results in polyethylene wear and osteolysis; but there was no increased benefit in ranges of motion compared with fixed-bearing implants. Further follow-up is needed to obtain long-term clinical and radiological results.

Total Hip Arthroplasty with Hydroxyapatite-Coated Cementless Acetabular Cup : Minimum 10-Year Follow-up Result / 대한정형외과학회잡지

PURPOSE: We report on minimum 10-year follow-up results of total hip arthroplasties with hydroxyapatite (HA)-coated cementless acetabular cups. MATERIALS AND METHODS: From January 1992 to October 1994, we performed one-hundred eight primary total hip replacements in ninety-seven patients using HA-coated cementless acetabular cup. Eighty-four cases in seventy-seven patients were followed-up for a minimum of 10 years. RESULTS: The mean Harris score was 54.7 (range, 0 to 77.2) points preoperatively and 88.5 (range, 27.1 to 100) points at the most recent follow-up. Revision procedures were required on twenty-eight (33.3%) hips. Thirteen (15.5%) cups were revised because of loosening. Seven (9.5%) hips among the eight that revealed excessive polyethylene wear and osteolysis were revised and one hip is waiting for the revision procedure. In seven (8.3%) cases, only a polyethylene liner exchange was performed because of excessive liner wear without osteolysis. The mean linear polyethylene wear was 2.74 mm. The mean linear wear rate was 0.28 mm per year and the corresponding estimate of volumetric wear was 1689.15 mm3. The mean linear polyethylene wear and linear wear rate in revised hips was 3.05 mm and 0.33 mm per year, respectively. The estimated volumetric wear in the revised group was 1882.27 mm3. CONCLUSION: HA-coated cementless acetabular cup (Atoll(R)) demonstrated a high rate of loosening and poor results in wear and osteolysis. Further studies are needed to promote the design of acetabular cups and the technique of HA coating.

Cementless Total Hip Arthroplasty with Circumferentially Proximal Porous-Coated Femoral Stem -Minimum 10-Year Follow-up Results

Purpose: The results of a more than 10-year follow-up after total hip arthroplasties with circumferential and proximal porous-coated femoral stems were evaluated. Materials and Methods: Seventy-six patients (80 hips), who were operated on between Aug. 1991 and July 1994, were followed for more than 10 years after primary total hip arthroplasties using Multilock stems. The mean age at the time of the operations was 47.3 years old and the mean duration of follow-up was 12.3 years. The clinical results and radiological findings were evaluated. Results: The mean Harris hip scores improved from 54.7 points to 88.5 points at the time of the 10-year follow up. On the last follow-up radiograph, endosteal bone formation was observed in 70 hips (90%) and all femoral stems were biologically stable. Femoral osteolysis, which was linear in Gruen zone I and VII and mostly restricted to the proximal zones, was observed in 67 hips (84%), and no hip had distal osteolysis in the femur. There was no loosening, migration, or revisions of the stems. Conclusion: Total hip arthroplasties using circumferential and proximal porous coated Multilock femoral stems demonstrated stable osseous fixation and no distal osteolysis for a minimum 10-year follow-up; therefore, all stems were reported to have satisfactory outcomes. With improvement of cup design and liner wear, circumferential and proximal porous coating designs of femoral stems can be an alternative answer to mechanical failure due to aseptic loosening.

Radiographic Analysis of the Tibial Axis on the Antero-posterior and Lateral view of Knee

PURPOSE: The purpose of this study is to evaluate the use of plain knee films in assessing the position of tibial component after total knee arthroplasty. MATERIALS AND METHODS: Plain radiological antero-posterior(AP) and lateral view of tibia of 51 adults (mean age: fifty-years old) were taken. On AP view, the medial angles between tibia plateau and mechanical, anatomical and proximal anatomical axis of tibia were measured, and then correlation of each angle and the angle between the tibia plateau and anatomical axis were assessed. On lateral view, the posterior angle formed between the medial tibial plateau and anatomical, proximal anatomical axis, anterior and posterior cortex of proximal tibia were measured, and then correlation of each angle and the angle between the medial tibial plateau and anatomical axis were assessed. RESULTS: On tibial AP view, both axes had significant correlation(p<0.05) with the anatomical axis. The anatomical axis of proximal tibia was closest to it. On lateral view, all three axes had significant correlation(p<0.05) with anatomical axis. Among these, the anterior cortex of proximal tibia was closest to it. CONCLUSION: The position of the tibia component and posterior slope after total knee arthroplasty can be measured on plain knee X-rays using anatomical axis and the anterior cortex line of proximal tibia.