Oxidized Zirconium Components Maintain a Smooth Articular Surface Except Following Hip Dislocation.

Background: Oxidized zirconium (OxZr) offers theoretical advantages in total hip and knee arthroplasty (THA and TKA, respectively) relative to other biomaterials by combining the tribological benefits of ceramics with the fracture toughness of metals. Yet, some studies have found that OxZr does not improve outcomes or wear rates relative to traditional bearing materials such as cobalt-chromium (CoCr). Separately, effacement of the thin ceramic surface layer has been reported for OxZr components, though the prevalence and sequelae are unclear.

Flexion contracture due to cyclops lesion after bicruciate-retaining total knee arthroplasty.

Flexion contracture may develop after total knee arthroplasty (TKA) and is usually associated with soft tissue contracture in the posterior compartment or hamstrings. A cyclops lesion is a soft tissue mass which can form in the anterior compartment usually after anterior cruciate ligament reconstruction and has been observed after bicruciate-retaining TKA. We have treated a patient who developed progressive loss of full extension from 0° to 20° after bicruciate-retaining TKA.

Relationship Between Functional Anatomy of the Hip and Surgical Approaches in Total Hip Arthroplasty.

Multiple surgical approaches have been used successfully for total hip arthroplasty. Minimally invasive surgery, defined by the length of the incision, has been associated with less blood loss and shorter length of stay compared with conventional total hip arthroplasty. Differences in early functional outcomes, as well as the risk of early and long-term complications, have been observed between different anatomic surgical approaches.

Novel Acetabular Cup for Revision THA Improves Hip Center of Rotation: A Radiographic Evaluation.

Background: Bone loss in patients undergoing revision THA poses a considerable challenge for orthopaedic surgeons. Often, to achieve better fixation in remaining bone, larger diameter acetabular components and reaming superiorly may be necessary. However, this is likely to raise the hip center of rotation, which may lead to altered biomechanics, specifically, insufficiency of the abductor muscles, altered gait, and increased risk of dislocation from impingement.

Effect of processing, sterilization and crosslinking on UHMWPE fatigue fracture and fatigue wear mechanisms in joint arthroplasty.

Ultra high molecular weight polyethylene (UHMWPE) has been used as a bearing surface in total joint replacements (TJR) for nearly five decades. This semi-crystalline polymer has extraordinary energetic toughness owing to its high molecular weight and entanglement density. However, it is challenged by a need to offer a combined resistance to fatigue, wear and oxidation in vivo.

Comparison of Head Center Position and Screw Fixation Options Between a Jumbo Cup and an Offset Center of Rotation Cup in Revision Total Hip Arthroplasty: A Computer Simulation Study.

Jumbo acetabular cups are commonly used in revision total hip arthroplasty (THA). A straightforward reaming technique is used which is similar to primary THA. However, jumbo cups may also be associated with hip center elevation, limited screw fixation options, and anterior soft tissue impingement.

Pelvic discontinuity: modern techniques and outcomes for treating pelvic disassociation.

Pelvic discontinuity is an uncommon condition that usually presents in the revision total hip arthroplasty population. However, its incidence will most likely increase due to the increasing number of primary and revision total hip arthroplasties (THA) done in recent years. Pelvic discontinuity (acetabular disassociation) is perhaps one of the more challenging cases for the hip arthroplasty surgeon to manage.

Do jumbo cups cause hip center elevation in revision THA? A radiographic evaluation.

Background: Acetabular revision THA with use of a large (jumbo) cup is an effective treatment for many cavitary and segmental peripheral bone defects. However, hip center elevation may occur with use of a jumbo cup owing to reaming superiorly and/or because of the increased diameter of the jumbo cup compared with the native acetabulum.

Questions/purposes: In our jumbo cup revision THAs, we attempted to avoid hip center elevation by placing the inferior edge of the cup at the inferior acetabulum.