Cranial flap fixation in sheep using a resorbable bone adhesive

Restricted access

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $505.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $600.00


The authors’ goal in this study was to investigate the use of a novel, bioresorbable, osteoconductive, wet-field mineral-organic bone adhesive composed of tetracalcium phosphate and phosphoserine (TTCP-PS) for cranial bone flap fixation and compare it with conventional low-profile titanium plates and self-drilling screws.


An ovine craniotomy surgical model was used to evaluate the safety and efficacy of TTCP-PS over 2 years. Bilateral cranial defects were created in 41 sheep and were replaced in their original position. The gaps (kerfs) were completely filled with TTCP-PS (T1 group), half-filled with TTCP-PS (T2 group), or left empty and the flaps fixated by plates and screws as a control (C group). At 12 weeks, 1 year, and 2 years following surgery, the extent of bone healing, local tissue effects, and remodeling of the TTCP-PS were analyzed using macroscopic observations and histopathological and histomorphometric analyses. Flap fixation strength was evaluated by biomechanical testing at 12 weeks and 1 year postoperatively.


No adverse local tissue effects were observed in any group. At 12 weeks, the bone flap fixation strengths in test group 1 (1689 ± 574 N) and test group 2 (1611 ± 501 N) were both statistically greater (p = 0.01) than that in the control group (663 ± 385 N). From 12 weeks to 1 year, the bone flap fixation strengths increased significantly (p < 0.05) for all groups. At 1 year, the flap fixation strength in test group 1 (3240 ± 423 N) and test group 2 (3212 ± 662 N) were both statistically greater (p = 0.04 and p = 0.02, respectively) than that in the control group (2418 ± 1463 N); however, there was no statistically significant difference in the strengths when comparing the test groups at both timepoints. Test group 1 had the best overall performance based on histomorphometric evaluation and biomechanical testing. At 2 years postoperatively, the kerfs filled with TTCP-PS had histological evidence of osteoconduction and replacement of TTCP-PS by bone with nearly complete osteointegration.


TTCP-PS was demonstrated to be safe and effective for cranial flap fixation in an ovine model. In this study, the bioresorbable, osteoconductive bone adhesive appeared to have multiple advantages over standard plate-and-screw bone flap fixation, including biomechanical superiority, more complete and faster bony healing across the flap kerfs without fibrosis, and the minimization of bone flap and/or hardware migration and loosening. These properties of TTCP-PS may improve human cranial bone flap fixation and cranioplasty.

ABBREVIATIONS TTCP-PS = tetracalcium phosphate and phosphoserine.
Article Information

Contributor Notes

Correspondence Brian J. Hess: LaunchPad Medical, Lowell, MA. WHEN CITING Published online February 7, 2020; DOI: 10.3171/2019.11.JNS192806.Disclosures Funding for this study was provided by Stryker. Drs. Foley, Woodard, and Slotkin are consultants to LaunchPad Medical. Mr. Hess, Mr. Brown, and Ms. Baldwin are employees of LaunchPad Medical. Mrs. Mayotte is an employee of Stryker. Other associations include the following. Dr. Foley: consultant for Medtronic; direct stock ownership in Digital Surgery Systems, Discgenics, DuraStat, Medtronic, NuVasive, nView Medical, Practical Navigation/Fusion Robotics, SpineWave, TDi, and Triad Life Sciences; patent holder with Medtronic and NuVasive; royalties from Medtronic; board of directors of Digital Surgery Systems, Discgenics, DuraStat, LaunchPad Medical, nView Medical, Practical Navigation/Fusion Robotics, TDi, and Triad Life Sciences. Dr. Woodard: ownership in LaunchPad Medical. Dr. Slotkin: direct stock ownership in LaunchPad Medical. Ms. Baldwin: employee of LaunchPad Medical. Mr. Brown: employee and stockholder in LaunchPad Medical. Mr. Hess: ownership in LaunchPad Medical.
  • 1

    Cochran DJones ASugita RBrown MGuda TPrasad H: Immediate dental implant stabilization in a canine model using a novel mineral-organic adhesive: four month results. Int J Oral Maxillofac Implants [in press] 2019

    • Search Google Scholar
    • Export Citation
  • 2

    Dashti SRBaharvahdat HSpetzler RFSauvageau EChang SWStiefel MF: Operative intracranial infection following craniotomy. Neurosurg Focus 24(6):E102008

    • Search Google Scholar
    • Export Citation
  • 3

    Donath KBreuner G: A method for the study of undecalcified bones and teeth with attached soft tissues. The Säge-Schliff (sawing and grinding) technique. J Oral Pathol 11:3183261982

    • Search Google Scholar
    • Export Citation
  • 4

    Farrar DF: Bone adhesives for trauma surgery: a review of challenges and developments. Int J Adhes Adhes 33:89972012

  • 5

    Gupta RAdeeb NGriessenauer CJMoore JMPatel ASThomas AJ: Removal of symptomatic titanium fixation plates after craniotomy. Acta Neurochir (Wien) 158:184518482016

    • Search Google Scholar
    • Export Citation
  • 6

    Kumar AMaartens NFKaye AH: Evaluation of the use of BioGlue in neurosurgical procedures. J Clin Neurosci 10:6616642003

  • 7

    Kwinta BMKrzyżewski RMKliś KMDonicz PGackowska MPolak J: Emergency reoperations in cranial neurosurgery. World Neurosurg 105:7497542017

    • Search Google Scholar
    • Export Citation
  • 8

    Lindner DSchlothofer-Schumann KKern BCMarx OMüns AMeixensberger J: Cranioplasty using custom-made hydroxyapatite versus titanium: a randomized clinical trial. J Neurosurg 126:1751832017

    • Search Google Scholar
    • Export Citation
  • 9

    Moles AHeudes PMAmelot ACristini JSalaud CRoualdes V: Long-term follow-up comparative study of hydroxyapatite and autologous cranioplasties: complications, cosmetic results, osseointegration. World Neurosurg 111:e395e4022018

    • Search Google Scholar
    • Export Citation
  • 10

    Mollman HDHaines SJ: Risk factors for postoperative neurosurgical wound infection. A case-control study. J Neurosurg 64:9029061986

    • Search Google Scholar
    • Export Citation
  • 11

    Motherway JAVerschueren PVan der Perre GVander Sloten JGilchrist MD: The mechanical properties of cranial bone: the effect of loading rate and cranial sampling position. J Biomech 42:212921352009

    • Search Google Scholar
    • Export Citation
  • 12

    Siswanto AChong S: Strength analysis of human skull on high speed impact. Int Rev Mech Eng 6:150815142012

  • 13

    Stoker MAForbes JAHanif RCooper CNian HKonrad PE: Decreased rate of CSF leakage associated with complete reconstruction of suboccipital cranial defects. J Neurol Surg B Skull Base 73:2812862012

    • Search Google Scholar
    • Export Citation


All Time Past Year Past 30 Days
Abstract Views 514 514 218
Full Text Views 66 66 18
PDF Downloads 44 44 12
EPUB Downloads 0 0 0
Google Scholar