Yong Huang1, Yi-Xin Zhou1, Hua Tian2, Jun-Wen Wang3, Wen-Guang Liu4, Hu Li5. 1. Department of Orthopaedics, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, China. 2. Orthopaedic Department, Peking University Third Hospital, Beijing, China. 3. Department of Orthopaedics and Traumatology, Wuhan Fourth Hospital (Puai Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. 4. Department of Joint Surgery and Sports Medicine, The Second Hospital of Shandong University, Jinan, China. 5. Department of Orthopaedic Surgery, Peking University People's Hospital, Beijing, China.
Abstract
OBJECTIVES: To investigate the cup survivorship, patient satisfaction level, clinical function, and radiographic outcomes of patients who underwent total hip arthroplasty (THA) using electron beam melting (EBM)-produced porous coated titanium cups at mid-term follow up. METHODS: A total of 32 patients (32 hips) from five hospitals in China who underwent primary THA using EBM-produced trabecular titanium cups between May and December 2012 were retrospectively reviewed. The inclusion criteria were: (i) patients who underwent THA with the use of EBM-produced cups with possible 7-year follow up; and (ii) patients with follow-up information, including the cup survivorship, patient satisfaction level, and clinical outcomes such as Harris hip score. The exclusion criteria were: (i) patients with neuropathic diseases; and (ii) patients who underwent THA due to neoplastic disease. Five (15.6%) patients were lost to follow up before the 7-year follow-up and, thus, were excluded; none of these patients died due to disease associated with the THA or had undergone removal of their cups as of our last evaluation. The mean age and body mass index of the patients were 59.37 (range: 38.00-69.00) years and 24.51 (range: 16.50-34.10) kg/m2 , respectively. Thirteen (48.1%) of the patients were female. RESULTS: The average duration of follow-up was 93.48 (range: 89.00-99.00) months. The median Harris hip score improved from 42.00 (interquartile range: 37.00-49.00) to 97.00 (interquartile range: 92.00-97.00) at the latest follow up (P < 0.001). A total of 18 (66.7%) patients rated their satisfaction level as very satisfied, 6 (22.2%) as satisfied, 2 (7.4%) as neutral and 1 (3.7%) as dissatisfied. No intraoperative or postoperative complications were identified. At the latest follow up, all cups were considered to have achieved osteointegration fixation, with three or more of the five signs evident in the most recent X-ray. However, three cups revealed radiolucent lines with a width of less than 1 mm. The median vertical and horizontal distances between the latest postoperative center of rotation relative to the anatomic center of rotation were 2.50 (interquartile range: -3.10, 6.94) mm superiorly and 3.26 (interquartile range: -8.12, 2.38) mm medially, respectively, at the most recent postoperative follow up. Kaplan-Meier survivorship analysis of cups, with the endpoint defined as postoperative radiolucent lines of less than 1 mm in width in at least two zones, reveals that the 8.25-year survival was 96.3% (95% confidence interval: 76.49%-99.47%). CONCLUSION: The mid-term follow-up of patients who underwent primary THA using EBM-produced porous coated titanium cups demonstrated favorable patient satisfaction, good clinical function, excellent survivorship, and adequate biological fixation.
OBJECTIVES: To investigate the cup survivorship, patient satisfaction level, clinical function, and radiographic outcomes of patients who underwent total hip arthroplasty (THA) using electron beam melting (EBM)-produced porous coated titanium cups at mid-term follow up. METHODS: A total of 32 patients (32 hips) from five hospitals in China who underwent primary THA using EBM-produced trabecular titanium cups between May and December 2012 were retrospectively reviewed. The inclusion criteria were: (i) patients who underwent THA with the use of EBM-produced cups with possible 7-year follow up; and (ii) patients with follow-up information, including the cup survivorship, patient satisfaction level, and clinical outcomes such as Harris hip score. The exclusion criteria were: (i) patients with neuropathic diseases; and (ii) patients who underwent THA due to neoplastic disease. Five (15.6%) patients were lost to follow up before the 7-year follow-up and, thus, were excluded; none of these patientsdied due to disease associated with the THA or had undergone removal of their cups as of our last evaluation. The mean age and body mass index of the patients were 59.37 (range: 38.00-69.00) years and 24.51 (range: 16.50-34.10) kg/m2 , respectively. Thirteen (48.1%) of the patients were female. RESULTS: The average duration of follow-up was 93.48 (range: 89.00-99.00) months. The median Harris hip score improved from 42.00 (interquartile range: 37.00-49.00) to 97.00 (interquartile range: 92.00-97.00) at the latest follow up (P < 0.001). A total of 18 (66.7%) patients rated their satisfaction level as very satisfied, 6 (22.2%) as satisfied, 2 (7.4%) as neutral and 1 (3.7%) as dissatisfied. No intraoperative or postoperative complications were identified. At the latest follow up, all cups were considered to have achieved osteointegration fixation, with three or more of the five signs evident in the most recent X-ray. However, three cups revealed radiolucent lines with a width of less than 1 mm. The median vertical and horizontal distances between the latest postoperative center of rotation relative to the anatomic center of rotation were 2.50 (interquartile range: -3.10, 6.94) mm superiorly and 3.26 (interquartile range: -8.12, 2.38) mm medially, respectively, at the most recent postoperative follow up. Kaplan-Meier survivorship analysis of cups, with the endpoint defined as postoperative radiolucent lines of less than 1 mm in width in at least two zones, reveals that the 8.25-year survival was 96.3% (95% confidence interval: 76.49%-99.47%). CONCLUSION: The mid-term follow-up of patients who underwent primary THA using EBM-produced porous coated titanium cups demonstrated favorable patient satisfaction, good clinical function, excellent survivorship, and adequate biological fixation.