PT  - JOURNAL ARTICLE
AU  - Ferrara, Lisa A.
AU  - Gordon, Ilya
AU  - Schlenk, Richard
AU  - Coquillette, Madeline
AU  - Fleischman, Aaron J.
AU  - Roy, Shuvo
AU  - Togawa, Daisuke
AU  - Bauer, Thomas W.
AU  - Benzel, Edward C.
TI  - In Vivo Assessment of Bone Graft/Endplate Contact Pressure in a Caprine Interbody Pseudarthrosis Model: A Preliminary Biomechanical Characterization of the Fusion Process for the Development of a Microelectromechanical Systems (MEMS) Biosensor
AID  - 10.1016/SASJ-2007-0102-RR
DP  - 2008 Jan 01
TA  - International Journal of Spine Surgery
PG  - 1--8
VI  - 2
IP  - 1
4099  - https://www.ijssurgery.com/content/2/1/1.short
4100  - https://www.ijssurgery.com/content/2/1/1.full
SO  - Int J Spine Surg2008 Jan 01; 2
AB  - Background In this preliminary study we used a goat model to quantify pressure at an interbody bone graft interface. Although the study was designed to assess fusion status, the concept behind the technology could lead to early detection of implant failure and potential hazardous complications related to motion-preservation devices. The purpose of this study was to investigate the feasibility of in vivo pressure monitoring as a strategy to determine fusion status.Methods Telemetric pressure transducers were implanted, and pressure at the bone graft interfaces of cervical interbody fusion autografts placed into living goats (Groups A and B) was evaluated. Group A constituted the 4-month survival group and Group B the 6-month survival group. One goat served as the study control (Group C) and was not implanted with a pressure transducer. An additional six cadaveric goat cervical spines (Group D) were obtained from a local slaughterhouse and implanted with bone grafts and ventral plates and used for in vitro biomechanical comparison to the specimens from Groups A and B.Results All goats demonstrated an increase in interface pressure within the first 10 days postoperatively, with the largest relative change in pressure occurring between the sixth and ninth days. The goats from Groups A and B had a 200% to 400% increase in relative pressure.Conclusions Although this was a pilot study to assess pressure as an indicator for a fusion or pseudarthrosis, the preliminary data suggest that early bone healing is detectable by an increase in pressure. Thus, pressure may serve as an indicator of fusion status by detecting altered biomechanical parameters.