Virtual reality-based surgical planning simulator for tumorous resection in FreeForm Modeling: an illustrative case of clinical teaching.

The importance of virtual reality (VR) has been emphasized by many medical studies, yet it has been relatively under-applied to surgical operation. This study characterized how VR has been applied in clinical education and evaluated its tutorial utility by designing a surgical model of tumorous resection as a simulator for preoperative planning and medical tutorial. A 36-year-old male patient with a femoral tumor who was admitted to the Affiliated Jiangmen Traditional Chinese Medicine Hospital was randomly selected and scanned by computed tomography (CT). The data in digital imaging and communications in medicine (*.DICOM) format were imported into Mimics to reconstruct a femoral model, and were generated to the format of *.stl executing in the computer-aided design (CAD) software SenSable FreeForm Modeling (SFM). A bony tumor was simulated by adding clay to the femur, the procedure of tumorous resection was virtually performed with a toolkit called Phantom, and its bony defect was filled with virtual cement. A 3D workspace was created to enable the individual multimodality manipulation, and a virtual operation of tumorous excision was successfully carried out with indefinitely repeated running. The precise delineation of surgical margins was shown to be achieved with expert proficiency and inexperienced hands among 43 of 50 participants. This simulative educator presented an imitation of high definition, those trained by VR models achieved a higher success rate of 86% than the rate of 74% achieved by those trained by conventional methods. This tumorous resection was repeatably handled by SFM, including the establishment of surgical strategy, whereby participants felt that respondent force feedback was beneficial to surgical teaching programs, enabling engagement of learning experiences by immersive events which mimic real-world circumstances to reinforce didactic and clinical concepts.

Can anterior vertebral body tethering provide superior range of motion outcomes compared to posterior spinal fusion in adolescent idiopathic scoliosis? A systematic review.

PURPOSE: Anterior vertebral body tethering (AVBT) was introduced as a fusionless alternative to treating adolescent idiopathic scoliosis (AIS) while preserving range of motion (ROM). This is the first systematic review to compare the ROM outcomes between AVBT and PSF in treating AIS. METHODS: We conducted a comprehensive search on PubMed, EMBASE, MEDLINE, and Cochrane Library. Inclusion criteria were patients with AIS treated with AVBT or PSF or both, and clearly defined ROM outcomes; exclusion criteria were scoliosis other than AIS, biomechanical or cadaveric studies, non-English publications, case reports, conference summaries, unpublished literature, commentaries, and reviews. Primary outcome was ROM. Secondary outcomes included Cobb angle correction, quality of life (QOL), complications, and muscle strength and endurance. RESULTS: Twelve studies were included in this review. We found moderate evidence to support that AVBT results in superior ROM outcomes than PSF while achieving comparable Cobb angle correction with low evidence. The comparison of QOL outcomes between AVBT and PSF remained inconclusive. In addition to the complications noted conventionally in PSF, AVBT could result in over-correction and distal adding-on. We also found very low evidence to support that AIS patients treated with AVBT have superior muscle strength and endurance when compared to those treated with PSF. CONCLUSIONS: AVBT provides better preservation of ROM and muscle strength postoperatively when compared with PSF, while achieving comparable curve correction. Future studies should explore the spinal growth trajectory to determine the window of opportunity for AVBT in AIS.

In vivo stimulation of bone formation by aluminum and oxygen plasma surface-modified magnesium implants.

A newly developed magnesium implant is used to stimulate bone formation in vivo. The magnesium implant after undergoing dual aluminum and oxygen plasma implantation is able to suppress rapid corrosion, leaching of magnesium ions, as well as hydrogen gas release from the biodegradable alloy in simulated body fluid (SBF). No released aluminum is detected from the SBF extract and enhanced corrosion resistance properties are confirmed by electrochemical tests. In vitro studies reveal enhanced growth of GFP mouse osteoblasts on the aluminum oxide coated sample, but not on the untreated sample. In addition to that a small amount (50 ppm) of magnesium ions can enhance osteogenic differentiation as reported previously, our present data show a low concentration of hydrogen can give rise to the same effect. To compare the bone volume change between the plasma-treated magnesium implant and untreated control, micro-computed tomography is performed and the plasma-treated implant is found to induce significant new bone formation adjacent to the implant from day 1 until the end of the animal study. On the contrary, bone loss is observed during the first week post-operation from the untreated magnesium sample. Owing to the protection offered by the Al2O3 layer, the plasma-treated implant degrades more slowly and the small amount of released magnesium ions stimulate new bone formation locally as revealed by histological analyses. Scanning electron microscopy discloses that the Al2O3 layer at the bone-implant interface is still present two months after implantation. In addition, no inflammation or tissue necrosis is observed from both treated and untreated implants. These promising results suggest that the plasma-treated magnesium implant can stimulate bone formation in vivo in a minimal invasive way and without causing post-operative complications.