BackgroundPolyetheretherketone (PEEK) has a wide range of clinical applications but does not directly bond to bone. Bulk incorporation of osteoconductive materials including hydroxyapatite (HA) into the PEEK matrix is a potential solution to address the formation of a fibrous tissue layer between PEEK and bone and has not been tested.Questions/purposesUsing in vivo ovine animal models, we asked: (1) Does PEEK-HA improve cortical and cancellous bone ongrowth compared with PEEK? (2) Does PEEK-HA improve bone ongrowth and fusion outcome in a more challenging functional ovine cervical fusion model?MethodsThe in vivo responses of PEEK-HA Enhanced and PEEK-OPTIMA® Natural were evaluated for bone ongrowth in the form of dowels implanted in the cancellous and cortical bone of adult sheep and examined at 4 and 12 weeks as well as interbody cervical fusion at 6, 12, and 26 weeks. The bone-implant interface was evaluated with radiographic and histologic endpoints for a qualitative assessment of direct bone contact of an intervening fibrous tissue later. Gamma-irradiated cortical allograft cages were evaluated as well.ResultsIncorporating HA into the PEEK matrix resulted in more direct bone apposition as opposed to the fibrous tissue interface with PEEK alone in the bone ongrowth as well as interbody cervical fusions. No adverse reactions were found at the implant–bone interface for either material. Radiography and histology revealed resorption and fracture of the allograft devices in vivo.ConclusionsIncorporating HA into PEEK provides a more favorable environment than PEEK alone for bone ongrowth. Cervical fusion was improved with PEEK-HA compared with PEEK alone as well as allograft bone interbody devices.Clinical RelevanceImproving the bone–implant interface with a PEEK device by incorporating HA may improve interbody fusion results and requires further clinical studies.

Most tibial osteotomies were centered at a point distal and caudal to the intended osteotomy position. Use of a TPLO system with a saw guide was associated with more accurate placement of the osteotomy and more accurate leveling of the tibial plateau.

The biodegraded cellulose acetate (CA)/poly-l-lactic acid (PLLA)/halloysite nanotube composite nanofiber membranes were fabricated for the preparation of gel polymer electrolytes (GPEs) used in lithium-ion batteries.

Anglo-American ontologies posit that gay men should come out to match their outer selves with their inner ones. In Confucianized Singapore, however, gay men refrain from coming out to their parents to avoid shaming their families. Instead, they couch their homosexuality in kinship terms and "go home" with their boyfriends (Chou, 2000). "Going home" gains familial acceptance, but it does not challenge mainstream discourses of homosexuality. By examining how Singaporean gay men negotiate their sexuality with their families, I question the validity of coming out and going home as both ontological discourses and strategies.

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