This concept has potential to improve the biologic fixation of porous reconstructive implants.

Various forms of pigmentary dysplasias have been known to be associated with chromosomal mosaicism. One of these disorders, known as phylloid hypomelanosis, has been found to be predominantly associated with abnormalities in chromosome 13. Most of the reported literature involves mosaic trisomy 13 with clinical evidence of abnormal pigmentation in the form of leaf‐like or oblong achromic macules following Blaschko's lines. Here, we report on an 8‐year‐old girl with phylloid hypomelanosis and precocious puberty who was found to have mosaicism for tetrasomy 13q in the form of inverted dup(13)(q21) on her skin fibroblasts as well as peripheral blood karyotype. A higher resolution (244K) chromosomal microarray was done on DNA from skin fibroblasts confirming the breakpoint and gain of distal 13q, which made her tetrasomic for 13q21‐qter. This is the first‐ever reported association of tetrasomy 13q with phylloid hypomelanosis and precocious puberty. Our report further emphasizes the need to exclude any type of abnormalities of chromosome 13 in patients with phylloid hypopigmentation. © 2009 Wiley‐Liss, Inc.

Background Noncemented revision arthroplasty is often complicated by the presence of bone implant gaps that reduce initial stability and biologic fixation. Demineralized bone matrix has osteoinductive properties and therefore the potential to enhance gap healing and porous implant fixation. Questions/purposes We determined at what times and to what extent demineralized bone matrix promotes gap healing and bone ingrowth around a porous implant. Methods We inserted porous titanium implants into the proximal metaphyses of canine femora and humeri, with an initial 3-mm gap between host cancellous bone and implants. We left the gaps empty (control; n = 12) or filled them with either demineralized bone matrix (n = 6) or devitalized demineralized bone matrix (negative control; n = 6) and left them in situ for 4 or 12 weeks. We quantified volume healing of the gap with new bone using threedimensional micro-CT scanning and quantified apposition and ingrowth using backscattered scanning electron microscopy. Results The density of bone inside gaps filled with demineralized bone matrix reached 64% and 93% of surrounding bone density by 4 and 12 weeks, respectively. Compared with empty controls and negative controls at 4 and 12 weeks, gap healing using demineralized bone matrix was two to three times greater and bone ingrowth and apposition were up to 15 times greater. Conclusions Demineralized bone matrix promotes rapid bone ingrowth and gap healing around porous implants. Clinical Relevance Demineralized bone matrix has potential for enhancing implant fixation in revision arthroplasty.

Objective: To evaluate bone regeneration in a heterogenous, deproteinized bone mineral (DBM) when used as an onlay graft. Materials and methods: In this study, eight rabbits received two titanium bone graft holders (TBGHs), one on the left and one on the right lateral surface of the mandible. Each TBGH possessed two cylindrical chambers, which were perforated with numerous sub-millimeter pores. On

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