Micro-arc oxidation (MAO) is an electrochemical method used to treat metal surfaces. It provides nanoporous pits, and thick oxide layers, and incorporates calcium and phosphorus into the coating layer of titanium alloy. This modification on the surface of titanium alloy by MAO coating would improve the ability of cementless stems to osseointegrate. In spite of these structural and chemical advantages, clinical study of total hip arthroplasty (THA) using MAO coated stem has not yet been reported. In this study, we evaluated the clinical and radiographic results associated with cementless grit-blasted tapered-wedge stems that were identical in geometry but differed with regard to surface treatment with or without MAO coating. We performed a retrospective review of 141 THAs using MAO coated stem for a minimum of 5 years and compared them to 219 THAs using the same geometry stem without MAO coating. A cementless Bencox femoral component (Corentec, Seoul, Korea) was used in all hips. It is made of titanium alloy with a straight, double wedged, tapered stem with a rectangular cross-section. Surface treatment was performed using grit blasting with a roughness of 5.5ųm that was available either with or without MAO coating. Clinical and radiographic evaluations were performed preoperatively and at 6 weeks, 3 months, 6 months, and 1 year postoperatively, and then annually.Introduction
Materials & Methods
Soft-tissue balancing is crucial in total knee arthroplasty, but proper release of medial collateral ligament is a challenging procedure. It has been well recognized that medial gap tends to be more tight than lateral gap in varus knees after surgery. The purpose of this study is to investigate the incidence and predictable factors of medial tibial bone remodeling following navigation-assisted total knee arthroplasty. One hundred and sixty-six consecutive patients (221 knees) who underwent navigation-assisted total knee arthroplasty and followed during a minimum of 1 year were included in this study. Radiographic examination including anteroposterior and lateral view of both knees were performed at a regular follow-up schedules of 6 weeks, 3 months, 6 months, 1 year and thereafter, annually after surgery. An independent investigator identified the presence of medial tibial bone remodeling at each follow-up. All information on potential factors affecting medial tibial remodeling were retrieved and classified into 2 types (patient- and surgery-related).Background and Purpose
Materials and methods