Results of Total Hip Arthroplasty with 36-mm Metallic Femoral Heads on 1st Generation Highly Cross Linked Polyethylene as a Bearing Surface in Less than Forty Year-old Patients: Minimum Ten-year Results / 대한고관절학회지

PURPOSE: We evaluated long-term clinical and radiographic results in patients underwent primary total hip arthroplasty (THA) using 36-mm metallic femoral head and 1st generation highly cross-linked polyethylene among patients aged 40 years and less, with minimum 10 years follow-up. MATERIALS AND METHODS: We retrospectively reviewed 20 hips underwent primary THA by one hip surgeon using 36-mm femoral head and 1st generation highly cross-linked polyethylene from 2004 to 2006. Mean follow up was 131.55 months. Clinical follow-ups included functional measurements. And we evaluated post operative complications, prosthesis loosening, failure, and osteolysis. For radiologic evaluations, together with position of acetabular cup at 6 weeks later of postoperation, we separately calculated the penentrations of femoral heads into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups. Polywear pro3D 5.10 software was used to measure penetrations of femoral head. RESULTS: Mean acetabular cup inclination and anteversion were 49.02° and 10.19°, respectively. Mean thickness of the polyethylene liner at 45° was 6.44 mm. There were no major complications such as implant loosening or osteolysis, and one case of dislocation occurred. Average modified Harris hip score at final follow-up was 91, and Merle d'Aubigne and Postel scores 15 were or over. Average femoral head penetration of bedding wear was 0.170±0.039 mm/year. Steady-state wear rates was 0.059±0.006 mm/year. CONCLUSION: Results of THA with 36-mm metallic femoral heads on 1st generation highly cross linked as a bearing surface in less than 40 year-old patients were satisfactory.

Results of Primary Total Hip Arthroplasty Using 36 mm Femoral Heads on 1st Generation Highly Cross Linked Polyethylene in Patients 50 Years and Less with Minimum Five Year Follow-up / 대한고관절학회지

PURPOSE: We evaluated the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on 1st generation highly cross-linked polyethylene (HXLPE) in patients 50 years and less with minimum five year follow-up. MATERIALS AND METHODS: We retrospectively reviewed 31 patients (41 hips) aged 50 years and less underwent primary THA with a 36 mm diameter femoral head on HXLPE between 2004 and 2010. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d'Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at six weeks later of postoperation, we separately calculated the penentrations of femoral head into polyethylene liners during postoperation and one year later check-ups, and during one year later check-ups and final check-ups. RESULTS: There were no major complications except for one case of dislocation. Average modified HHS at final follow-up was 88 (81-98), and Merle d'Aubigne and Postel scores were more than 15. Mean acetabular cup inclination and anteversion were 45.81°(36.33°-54.91°) and 13.26°(6.72°-27.71°), respectively. Average femoral head penetration of steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.042±0.001 mm/year. CONCLUSION: Based on minimum 5 years clinical results, we think 36 mm metal head coupling with HXLPE as the good alternate articulation surface when planning THA for patients aged 50 years and less.

Results of Primary Total Hip Arthroplasty with 36-mm Femoral Heads on Highly Cross-linked Polyethylene-Minimum Seven-years Follow-up / 대한고관절학회지

PURPOSE: We evaluate the clinical and radiographic midterm results of primary total hip arthroplasty (THA) using a 36 mm diameter femoral head on highly cross-linked polyethylene (minimum 7-year follow-up). MATERIALS AND METHODS: We retrospectively reviewed 73 patients (74 hips) that underwent primary THA with a 36 mm diameter femoral head on highly cross-linked polyethylene between July 2004 and February 2007. Clinical follow-ups included specific measurements like modified Harris hip scores (HHS) and Merle d'Aubigne and Postel score. For radiologic evaluations, together with position of acetabular cup at 6 weeks later of post-operation, we separately calculated the penentrations of femoral heads into polyethylene liners during post-operation and one year later check-ups, and during one year later check-ups and final check-ups. RESULTS: There were no complications except for one case of dislocation. Average modified HHS at final follow-up was 88+/-7.5 (range, 81-96), and Merle d'Aubigne and Postel scores were more than 15 (range, 15-18). Mean acetabular cup inclination and anteversion were 50.1degrees(range, 35degrees-58degrees) and 23.6degrees(range, 5degrees-38degrees), respectively. Average femoral head penetration during the first postoperative year was 0.071+/-0.034 mm/year, and steady-state wear rate determined using radiographs taken at one-year postoperatively and at latest follow-up was 0.051+/-0.022 mm/year. Average femoral head penetration during entire follow-ups was 0.058+/-0.013 mm/year. CONCLUSION: Primary THA with a large diameter femoral head on highly cross-linked polyethylene was found to produce the results comparable to previous in vitro laboratory hip simulation studies. And we also find out good scores in terms of patient's functionality.