Biphasic calcium phosphate (BCP) with a characteristic needle-shaped submicron surface topography (MagnetOs) has attracted much attention due to its unique bone-forming ability which is essential for repairing critical-size bone defects such as those found in the posterolateral spine. Previous in vitro and ex-vivo data performed by van Dijk LA and Yuan H demonstrated that these specific surface characteristics drive a favorable response from the innate immune system.

This study aimed to evaluate and compare the in vivo performance of three commercially-available synthetic bone grafts, (1) i-FACTOR Putty^®, (2) OssDsign^® Catalyst Putty and (3) FIBERGRAFT^® BG Matrix, with that of a novel synthetic bone graft in a clinically-relevant instrumented sheep posterolateral lumbar spine fusion (PLF) model. The novel synthetic bone graft comprised of BCP granules with a needle-shaped submicron surface topography (MagnetOs) embedded in a highly porous and fibrillar collagen matrix (MagnetOs Flex Matrix).

Four synthetic bone grafts were implanted as standalone in an instrumented sheep PLF model for 12 weeks (n=3 bilateral levels per group; levels L2/3 & L4/5), after which spinal fusion was determined by manual palpation, radiograph and µCT imaging (based on the Lenke scale), range-of-motion mechanical testing, and histological and histomorphological evaluation.

Radiographic fusion assessment determined bilateral robust bone bridging (Lenke scale A) in 3/3 levels for MagnetOs Flex Matrix compared to 1/3 for all other groups. For µCT, bilateral fusion (Lenke scale A) was found in 2/3 levels for MagnetOs Flex Matrix, compared to 0/3 for i-FACTOR Putty^®, 1/3 for OssDsign^® Catalyst Putty and 0/3 for FIBERGRAFT^® BG Matrix. Fusion assessment for MagnetOs Flex Matrix was further substantiated by histology which revealed significant graft resorption complemented by abundant bone tissue and continuous bony bridging between vertebral transverse processes resulting in bilateral spinal fusion in 3/3 implants.

These results show that MagnetOs Flex Matrix achieved better fusion rates compared to three commercially-available synthetic bone grafts when used as a standalone in a clinically-relevant instrumented sheep PLF model.

Introduction: Virtual Reality arthroscopic training systems offer the potential for improved training, assessment and evaluation of surgical skills. Of the various virtual reality arthroscopic training systems available, the main limiting factors preventing their use as a standard training tool is the lack of force feedback. No force data is available from in vivo measurements, which would serve as the basis for the development of such a system. Methodology: We attached a six axis force torque (FT) sensor to a standard arthroscopic probe while at the same time making necessary modiþcations to meet the safety and sterility requirements, and measured in vivo the forces and torques generated during various standard tasks of a routine knee arthroscopy. [The procedure was split into 11 separate tasks] A simultaneous video recording of the procedure was made and synchronized to the force torque recording by using an audio signal. A pilot study to evaluate the difference between experienced and less experienced arthroscopists was also undertaken. Results and conclusions: For comparison and evaluation purposes the vectored XY torque recording was used. Comparison between junior and senior arthroscopic surgeons was done by assessing the XY Torque distribution over time and evaluation of the graph patterns generated while performing similar tasks. Though differences can be seen, it did not show any statistical signiþcance. Successful completion of an arthroscopic procedure requires adequate visualization and gentle manipulation of instruments and tissues within the knee. The use of a force torque sensor in arthroscopic training systems will allow detection of and warn when excessive potentially damaging forces are being used. This will provide a means for improving training as well as a method of evaluation, including revalidation.