title: Evaluation of cranial bone transport distraction with and without adipose grafting.
abstract: Transport distraction osteogenesis (DO) can be used to autologously reconstitute calvarial defects. The purpose of this study is to histomorphologically interrogate osteogenic formation during cranial transport distraction using a novel device. We also evaluate the effect of fat grafting on the regenerate and soft-tissue stability during distraction. This study was approved by Yale IACUC. Ten male New Zealand white rabbits (3 mo; 3.5 kg) were used (8 treatment, 2 control). A 16 × 16 mm defect was created abutted by a 10 × 16 mm transport disc. The device was fixated anterioposteriorly. Four animals were fat-grafted using 2 mL of subdermal intrascapular fat deposited along the distraction site. Latency (1 d), active distraction (12-14 d) (1.5 mm/d), and consolidation (4 wk) followed. Calcein and xylene orange fluorochromes were injected subcutaneously during and post-distraction to mark sites of bone formation. Following sacrifice, osteogenesis was assessed using microCT, histology, and fluorescence. Treatment animals demonstrated regenerate bone between distracted segments on microCT. MicroCT analysis of non-fat-grafted and fat-grafted animals revealed a mean density of 2271.95 mgHA/ccm and 2254.27 mgHA/ccm (P = 0.967), respectively, and defect bone versus total volume (BV/TV) of 0.0999 and 0.0766 (P = 0.5979), respectively. Controls had minimal reossification. Histologically, mean densities measured 43.63% and 8.19%, respectively. Fluorescence revealed ossification from the callus as well as from dura and periosteum in the cranial defect. Transport distraction is effective to reconstruct critically sized rabbit calvarial defects. Regenerate bone arises predominantly from the callus with contribution from surrounding dura and periosteum. Adipose grafting is well tolerated but does not enhance osseous regeneration.
authors.affiliation: From the *Oral and Maxillofacial Surgery, University Medical Centre Mainz and Yale School of Medicine, New Haven; †Section of Plastic and Reconstructive Surgery, Yale School of Medicine, New Haven; ‡Bioimaging Science, Yale University, New Haven; and §Yale Core Center for Musculoskeletal Disorders, New Haven, Connecticut.
authors.forename: Felix P
authors.initials: FP
authors.lastname: Koch
authors.forename: Mikell M
authors.initials: MM
authors.lastname: Yuhasz
authors.forename: Rob
authors.initials: R
authors.lastname: Travieso
authors.forename: Kenneth
authors.initials: K
authors.lastname: Wong
authors.forename: James
authors.initials: J
authors.lastname: Clune
authors.forename: Zhen W
authors.initials: ZW
authors.lastname: Zhuang
authors.forename: Joshua
authors.initials: J
authors.lastname: Van Houten
authors.forename: Derek M
authors.initials: DM
authors.lastname: Steinbacher
mesh_terms: D000273:Adipose Tissue / Q000637:transplantation*; D000818:Animals; D015519:Bone Density / Q000502:physiology; D001847:Bone Diseases / Q000601:surgery; D001861:Bone Regeneration / Q000502:physiology; D002146:Bony Callus / Q000473:pathology; D004388:Dura Mater / Q000473:pathology; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D010012:Osteogenesis / Q000502:physiology; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods*; D010521:Periosteum / Q000473:pathology; D011817:Rabbits; D011897:Random Allocation; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods*; D012886:Skull / Q000601:surgery*; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; C007740:fluorexon