Once Annealed Highly Cross-Linked Polyethylene Exhibits Low Wear at 9 to 15 Years.

A once annealed highly cross-linked polyethylene (HXLPE) was introduced in 1998. Concerns regarding its long-term performance and oxidative resistance exist because of the presence of retained free radicals. The authors studied 48 patients with 50 hip implants having an average age of 62 years.

Second-Generation Annealed Highly Crosslinked Polyethylene has Low Wear at Mean Seven Year Follow-up.

First-generation once annealed highly crosslinked polyethylene (HXLPE) has perfomed well for over 10 years but the presence of free radicals remain a concern. A second-generation sequentially annealed HXLPE was developed to further reduce wear, maintain mechanical strength, and enhance oxidative resistance.

Periprosthetic fractures around a cementless hydroxyapatite-coated implant: a new fracture pattern is described.

Background: Periprosthetic fractures can occur both intraoperatively and postoperatively with implantation of cementless tapered stems.

Questions/purposes: In a large cohort of patients receiving cementless, proximally hydroxyapatite-coated femoral implants, we answered the following questions: What was the incidence of intraoperative and postoperative fractures associated with the implant? What were the fracture patterns as classified by the Vancouver classification system? Did the Vancouver classification represent the fracture patterns found? How were the fractures treated and what were the treatment outcomes; that is, how many fractures healed and did the stems osseointegrate?

Methods: We evaluated 1039 hips (932 patients) from three prospective studies. The hips were divided into three groups: no fractures, intraoperative fractures, and postoperative fractures.

High survivorship with a titanium-encased alumina ceramic bearing for total hip arthroplasty.

Background: Although ceramic-on-ceramic bearings for total hip arthroplasty (THA) show promising results in terms of bearing-surface wear, fracture of the bearing, insertional chips, and squeaking remain a concern.

Questions/purposes: Our primary objective of this report was to determine overall survivorship of a titanium-encased ceramic-on-ceramic bearing couple. Our secondary objectives were to evaluate for ceramic fracture, insertional chips, osteolysis, and device squeaking.

Second-generation annealed highly cross-linked polyethylene exhibits low wear.

Background: Compared with conventional polyethylene, first-generation highly cross-linked polyethylenes have low wear, but controversy exists regarding their reduced mechanical strength and/or retained free radicals. Second-generation highly cross-linked polyethylenes have been developed to reduce wear, maintain mechanical strength, and have oxidative resistance, but it is unclear whether they do so.

Questions/purposes: The primary objective of this study therefore was to determine if a second-generation annealed material has low linear wear at 5 years followup.