Primary Total Hip Arthroplasty Using Non-cemented Multilock Proximal Porous Coated Femoral Stem: Ten to Twelve Years Follow Up Study / 대한정형외과학회잡지

PURPOSE: This study evaluated the minimum ten-year result of primary total hip arthroplasty with a non-cemented Multilock femoral stem. MATERIALS AND METHODS: Fifty five total hip replacements in forty-four patients using a non-cemented Multilock femoral stem and Harris-Galante 2 acetabular component were performed between January 1992 and December 1994. Forty-four hips in thirty-six patients were available for follow up for an average of eleven years (range, ten to twelve years). The clinical results were evaluated based on the Harris hip scores. A detailed radiography analysis was performed by an evaluation of the radiolucent lines, femoral osteolysis, and fixation stability by Engh Method. RESULTS: The average Harris hip score improved from 54.3 points preoperatively to 93.6 points postoperatively. Non-progressive radiolucencies < 2 mm in width were observed in nine (20.5%), and femoral osteolysis was observed in thirteen cases (29.5%). For the fixation stability, osseous ingrowth was noted in thirty nine cases (88.6%) and fibrous ingrowth was observed in two (4.5%). There were three (6.8%) cases with unstable fixation. Two hips underwent revision. The survival rate of the femoral component was 93.2% (forty one cases) after a minimum ten-year follow up. CONCLUSION: The non-cemented Multilock femoral component provided excellent clinical and radiographic results. However, the rate of femoral osteolysis was relatively high (mostly restricted to zone 1 and 7).

Bipolar Hemiarthroplasty Using Non-cemented Multilock Femoral Stem: A 7-year Minimum Follow-up Study

Purpose: To evaluate the clinical and radiographic results of primary bipolar arthroplasty during average 9.8-year period, using a non-cemented Multilock femoral stem and a biarticular acetabular cup. Materials and Methods: This study included 24 patients (29 hips) who underwent primary bipolar hemiarthroplasties with Multilock femoral stems and biarticular cups and who could be followed for more than seven years. Clinically, we evaluated the Harris Hip scores and patient complaints of thigh and inguinal pain. We also evaluated the radiographic measurements around the femoral stems and the bipolar cups. Results: The average Harris Hip score improved from 57.4 points to 91.6 points; and 3 (10.3%) hips were associated with thigh pain and 4 (13.8%) hips with inguinal pain. Around the femoral stem there was a non-progressive radiolucent line less than 1 mm in length in 4 (13.8%) hips and osteolysis was present in 6 (20.6%) hips. With respect to the stability of the fixations, there was osseous ingrowth in 26 (89.7%) hips and fibrous ingrowth in 3 (10.3%) hips. Around the acetabulum there was osteolysis in 5 (17.2%) hips, proximal migration of the cup in 2 (6.9%) hips, and erosion of the acetabular cartilage in 10 (34.5%) hips. There were 3 (10.3%) biarticular cups, which were converted to total hip arthroplasties, but no femoral stems were revised. The overall failure rate of the primary operations was 10.3%. Conclusion: The current study demonstrated favorable results after bipolar hemiarthroplasties with Multilock femoral stems. However, the osteolysis that occurred around the femoral stems and the acetabula emerged as a problem after the total hip arthroplasties. In particular, it is expected that the osteolysis would increase over time and become the main cause for the need for surgical revision.

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.

Cementless Total Hip Arthroplasty Using the Mutilock Femoral Stem

PURPOSE: This study was conducted to evaluate the development of osteolysis and the outcome of performing primary total hip arthroplasty using a non-cemented Multilock femoral stem with a proximal circumferential porous coating. The patients were followed up for a minimum of five year and we include the follow-up clinical and radiological results. MATERIALS AND METHODS: We reviewed the clinical and radiological results of 44 total hip arthroplasties in 40 patients, and these patients were available for a minimum of 5 years follow-up (average: 90.6 months), A Multilock femoral stem and Harris-Galante II acetabular component was used in all the operations, and the operations were performed between June 1993 and February 1997. RESULTS: The average Harris hip score improved from 54.5 points preoperatively to 91.5 points postoperatively. The stability of the femoral stem, based on Engh's evaluation schema, showed stability with osseous ingrowth being noted in 43 cases (98%), stability with fibrous ingrowth being noted in 1 case (2%), and there was no unstable fixation. Femoral osteolysis occurred in 17 cases (38%), which was mostly restricted to zones I and VII. Acetabular osteolysis occurred in 9 cases (20.5%), with zone II being the most common location. There were no cases of femoral stem revision. 7 cases of acetabular revision were done due to polyethylene liner dissociation in 3 cases and osteolysis of a large area in 4 cases. The mean revision period was 73 months (range: 37~112) from the initial operation. CONCLUSION: The femoral stem was devised to press fit through the circumferential proximal porous coating and the flute type distal stem has the benefit of excellent fixation and prevention of particle invasion to the distal bone canal, which is caused by proximal bone ingrowth. However, the frequency of revision was great due to the increased rate of wear by the structural defect of the Harris-Galante type II acetabular cup and the high occurrence of osteolysis.

Cementless Total Hip Arthroplasty Using Circumferentially Porous Coated Femoral Stem: Minimum Five-Year Followup Study / 대한정형외과학회잡지

PURPOSE: The result of more than 5 year follow up after cementless total hip arthroplasty using circumferentially porous coated femoralstem was evaluated. MATERIALS AND METHODS: Eighty five patients (95 hips) were followed more than 5 years after a primary total hip arthroplasty using multilockfemoral stem, which was circumferentially porous coated at the proximal 1/3 of femoral stem. The average age at the time of operation was 48 years. The average duration of followup was 6.9 years. The Harris hip score was used for the evaluation of clinical results. The canal fit of the stem at the proximal canal and isthmus level was evaluated from the postoperative radiographs. The component stability, endosteal bone formation, radiolucent line, osteolysis and polyethylene wear were evaluated from serial followup radiographs. RESULTS: The mean Harris hip scores increased from 60.1 points preoperatively to 91.3 points at the time of the most recent followup. All hips had a press fit at both the proximal canal and isthmus level. On the lastest followup radiograph, endosteal bone formation was observed in all cases (100%). The radiolucent line around the femoral stem was observed in 92 cases (97%), mainly Gruen zones II, III, IV, V and VI. The radiolucent line was thinner than 1 mm and there was no progressive widening. The acetabular osteolysis developed in 31 cases(33%) and the femoral osteolysis in 31 cases (33%) mostly in Gruen zones I, II, and VII. There was no distal osteolysis in the femur. There was no loosening or migration of cup and stem. The mean linear wear was 1.29 (0-5.69) mm and the mean rate of linear wear was 0.18(0-0.81) mm/year. Seventeen hips (18%) were revised for the dissociation of polyethylene liner in 10 hips (11%), excessive wear in the polyethylene liner and progressive osteolysis in 6 hips (6%) and recurence of tuberculous arthritis in 1 hip (1%). CONCLUSION: Cementless total hip arthroplsty using circumferentially porous coated femoral stem showed good medium-term results clinicallyand radiologically, it is likely that circumferential porous coating in the femoral stem induces bone ingrowth and prevents distal osteolysis.

Femoral Osteolysis in Total Hip Arthroplasty with Circumferentially Porous Coated Multilock(R) Femoral Stem / 대한정형외과학회잡지

PURPOSE: To assess the follow up results of more than five years of total hip arthroplasty using circumferencially porous coated Multilock(R) femoral stem and to determine the prevalence of femoral osteolysis. MATERIALS AND METHODS: We assessed the Harris hip score, fit of the stem, fixation status at the latest follow up, radiolucent lines, and stress shielding of 71 cases in 60 patients. RESULTS: The average Harris hip score improved from 51.4 points preoperatively to 91.7 points at the latest follow up. Radiologic analysis revealed excellent bony ingrowth (93%), while 10 hips (14.1%) revealed femoral osteolyis mostly in zones I and VII. CONCLUSION: The midterm results of using the Multilock(R) stem showed excellent bony ingrowth. Osteolytic lesions were primarily limited to proximal zones I and VII, except 1 hip. It may be possible to protect from migration of the polyethylene debris paticle to the distal portion due to the excellent cirumferential osteointegration. Further follow up is required to determine the real prevalence of distal osteolysis.