Minimum four year Follow up of Primary Total Hip Arthroplasty Using Contemporary Titanium Tapered stems in Korean Patients

초록

Summit® stems. Materials and Methods: After a minimum of 4 years of follow-up, 85 arthroplasties in 91 patients were reviewed retrospectively from December, 2004 to March, 2012. Mean age was 58.4 years (range, 31-87). Mean postoperative follow up period was 69.2. months (range, 48-137). Results: The mean Harris score was 69 points (range, 58-97) preoperatively, and it improved significantly to 94 points (range, 84-100) at the final follow-up. Postoperatively, 8 patients(8.8%) experienced thigh pain, 5 patients (5.5%) showed moderate limping gait. The Kaplan-Meier survival analysis showed a survival rate of 98.9% at 4 years, with failure defined as revision for any reason. There was no early stem subsidence and no more subsidence after postoperatively at 6 weeks. Of the 91 hips, 84 (92%) showed radiographic signs of stem bone ingrowth including Gruen's zone 3 and 5 at last follow-up. Stress shielding occurred in 59 hips (64.8%) and third degree stress shielding was observed in 7 hips (7.7%). Complication were 5 hips (5.5%) of dislocation. Although revision because of recurrent dislocation led to acetabular component revision in 1 hips (1.1%), there were no revisions because of isolated aseptic loosening of the femoral component. And 6 hips (6.6%) required circumferential wiring due to a calcar crack sustained during stem insertion. But, these intraoperative cracks were healed without migration of the stems and other additional problems. Conclusion: The clinical and radiological mid-term results of primary THA using Summit® stems achieved good initial fixation. Careful longterm follow-up and observation will be necessary for hips in which stress shielding occurs. Acknowledgment: This study was supported by Inha University hospital Keywords: THA, Summit stem, Titanium Tapered stems