Augmented Reality to Assist Skin Paddle Harvesting in Osteomyocutaneous Fibular Flap Reconstructive Surgery: A Pilot Evaluation on a 3D-Printed Leg Phantom

BackgroundAugmented Reality (AR) represents an evolution of navigation-assisted surgery, providing surgeons with a virtual aid contextually merged with the real surgical field. We recently reported a case series of AR-assisted fibular flap harvesting for mandibular reconstruction. However, the registration accuracy between the real and the virtual content needs to be systematically evaluated before widely promoting this tool in clinical practice. In this paper, after description of the AR based protocol implemented for both tablet and HoloLens 2 smart glasses, we evaluated in a first test session the achievable registration accuracy with the two display solutions, and in a second test session the success rate in executing the AR-guided skin paddle incision task on a 3D printed leg phantom.MethodsFrom a real computed tomography dataset, 3D virtual models of a human leg, including fibula, arteries and skin with planned paddle profile for harvesting, were obtained. All virtual models were imported into Unity software to develop a marker-less AR application suitable to be used both via tablet and via HoloLens 2 headset. The registration accuracy for both solutions was verified on a 3D printed leg phantom obtained from the virtual models, by repeatedly applying the tracking function and computing pose deviations between the AR-projected virtual skin paddle profile and the real one transferred to the phantom via a CAD/CAM cutting guide. The success rate in completing the AR-guided task of skin paddle harvesting was evaluated using CAD/CAM templates positioned on the phantom model surface.ResultsOn average, the marker-less AR protocol showed comparable registration errors (ranging within 1-5 mm) for tablet-based and HoloLens-based solution. Registration accuracy seems to be quite sensitive to ambient light conditions. We found a good success rate in completing the AR-guided task within an error margin of 4 mm (97% and 100% for tablet and HoloLens, respectively). All subjects reported greater usability and ergonomics for HoloLens 2 solution.ConclusionsResults revealed that the proposed marker-less AR based protocol may guarantee a registration error within 1-5 mm for assisting skin paddle harvesting in the clinical setting. Optimal lightening conditions and further improvement of marker-less tracking technologies have the potential to increase the efficiency and precision of this AR-assisted reconstructive surgery.

The role of folded fibular flap in patients’ reconstruction of mandibular defects: a retrospective clinical study

This study has analyzed 41 patients with mandibular ameloblastoma who underwent a partial mandibulectomy and reconstruction by folding the free fibular flap. In the preoperative and postoperative (6 months and 24 months after surgery), the Quality of Life (QOL) of these patients was assessed by using the University of Washington Quality of Life Questionnaire (UW-QOL) and the medical outcome study short form-36 (SF-36) questionnaires. SPSS 20.0 statistical software was used to conduct statistical analysis on the base data of the two groups of patients. Independent sample t test was conducted for sf-36 and UW-QOL scores at two time points in each group. The SF-36 survey showed that body pain (54.54 ± 8.10), general health (55.27 ± 7.54), and health changes (58.29 ± 9.60) decreased significantly at 6 months after surgery, but the mean score at 24 months after surgery all exceeded the preoperational level. At 24 months after the surgery, the vitality (80.41 ± 3.74), social function (81.61 ± 4.07), emotional role (82.39 ± 4.07), psychological health (81.66 ± 4.37) and total score (704.00 ± 31.53) all returned to the preoperative level, which was statistically significant compared with 6 months after surgery. However, there was no significant difference compared with the preoperative level. The UW-QOL survey showed that chewing (56.68 ± 7.23), speech (54.54 ± 7.7) and taste (62.29 ± 10.15) have significantly changed at 6 months after the surgery, and the difference was statistically significant at 24 months after surgery. Saliva generation decreased slightly (80.76 ± 3.35) at 6 months after surgery, but quickly returned to the preoperative level (81.59 ± 4.06). The total score of the patients almost recovered to the preoperative level at 24 months after surgery. The folded the fibular flap can not only repair the defects of soft tissue and bone tissue, but also restore the height of the alveolar ridge to, avoid the imbalance of crown and root ratio after implantation and reduce the occurrence of peri-implant inflammation, so that a true functional reconstruction can be realized.

Hypotrophic Clavicle Pseudoarthrosis Treatment: a Case Report

Background. The treatment of post-traumatic of the clavicle false joint remains a subject of discussion regarding the technology of the surgical intervention. Recently, the use of vascularized fibular flap reconstruction technique has been popularized, but the potential of the external osteosynthesis remains relevant. Clinical case description. A 70-year-old patient got a fracture of the middle third of the left clavicle diaphysis as a result of a fall. He underwent four surgical treatment options: plate osteosynthesis; plate osteosynthesis + bone autoplasty; plate osteosynthesis + vascularized fibular flap reconstruction; external osteosynthesis. A month after the fourth attempt of surgical treatment, fusion, improvement of the function of the right upper limb and the quality of life of the patient were achieved. Technological inaccuracy, namely, the lack of the fragments fixation stability due to the incorrectly chosen length of the plate, as well as an incomplete assessment of the anamnesis and the identified cognitive behavioral features of the patient, are considered as possible reasons for the treatment failure. Conclusion. Attempts of surgical treatment using plates in combination with bone autoplasty, including vascularized skin-bone flaps, do not always ensure the achievement of clavicle fractures fusion. In such situations, it is advisable to use the potential of external osteosynthesis with the reasonable planning.

Deviation Analyses of Computer-Assisted, Template-Guided Mandibular Reconstruction With Combined Osteotomy and Reconstruction Pre-Shaped Plate Position Technology: A Comparative Study

BackgroundComputer-assisted and template-guided mandibular reconstruction provides higher accuracy and less variation than conventional freehand surgeries. The combined osteotomy and reconstruction pre-shaped plate position (CORPPP) technique is a reliable choice for mandibular reconstruction. This study aimed to evaluate the accuracy of CORPPP-guided fibular flap mandibular reconstruction and analyze the possible causes of the deviations.Patients and MethodsFrom June 2015 to December 2016, 28 patients underwent fibular flap mandibular reconstruction. Virtual planning and personalized CORPPP-guided templates were applied in 15 patients while 13 patients received conventional freehand surgeries. Deviations during mandibulectomy and fibular osteotomy, and overall and triaxial deviation of the corresponding mandibular anatomical landmarks were measured by superimposing the pre- and postoperative virtual models.ResultsThe deviation of the resection line and resection angle was 1.23 ± 0.98 mm and 4.11° ± 2.60°. The actual length of fibula segments was longer than the designed length in 7 cases (mean: 0.35 ± 0.32 mm) and shorter in 22 cases (mean: 1.53 ± 1.19 mm). In patients without ramus reconstruction, deviations of the ipsilateral condylar head point (Co.), gonion point (Go.), and coracoid process point (Cor.) were 6.71 ± 3.42 mm, 5.38 ± 1.71 mm, and 11.05 ± 3.24 mm in the freehand group and 1.73 ± 1.13 mm, 1.86 ± 0.96 mm, and 2.54 ± 0.50 mm in the CORPPP group, respectively, with significant statistical differences (p < 0.05). In patients with ramus reconstruction, deviations of ipsilateral Co. and Go. were 9.79 ± 4.74 mm vs. 3.57 ± 1.62 mm (p < 0.05), and 15.17 ± 6.53 mm vs. 4.36 ± 1.68 mm (p < 0.05) in the freehand group and CORPPP group, respectively.ConclusionMandibular reconstructions employing virtual planning and personalized CORPPP-guided templates show significantly higher predictability, convenience, and accuracy of mandibular reconstruction compared with conventional freehand surgeries. However, more clinical cases were required for further dimensional deviation analysis. The application and exploration of clinical practice would also continuously improve the design of templates.

Determining the Effectiveness of Different Reconstruction Method and Mandibular Implants for Fracture in the Mandible

Introduction: Every year, many people suffer from mandibular defects due to various reasons such as trauma or malignant tumors. Various techniques for reconstructing mandibular defects have always been considered by surgeons and maxillofacial specialists to select the best option and achieve the desired results for the patient. In this study, various articles and their techniques for reconstruction of mandibular defects were reviewed and their results were reported. Materials and Methods: The present study is a systematic review study in which the keywords implants, mandibular, trauma, reconstruction of the desired articles in two databases pubmed and science direct from January 1, 2010 to August 31, 2018 And were selected and then examined. Results: 33 articles met the inclusion criteria on which the final review was performed. 17 articles were clinical studies, 9 articles were case reports and 7 articles were reviews. In these 33 studies, various techniques were examined, including the use of free vascularized fibular flap, the use of computer software, and the prototyping technique. Conclusion: Among the existing methods, the use of free vascularized fibular flap has been approved as a widely used and reliable method in various studies, and many researchers believe that this technique is the gold standard for the reconstruction of mandibular defects. The use of computer software was also used as a complementary technique to improve surgical outcomes.

Computer-assisted resection of mandibular cancer and repair with fibula free flap. Case report

Oral cancer is a disease, in the treatment of which the surgical resection of the lesion plays a lead- ing role. Oncological resections in the maxillofacial area create large deficits that affect the functionality and aesthetics of the patient to a large extent, while many times make oncological resection impossible due to their inability to restore. The mandibular deficits are particularly difficult, with the free osteocutaneous fibular flap being the gold standard in repairing large mandibular deficits. In recent years, technology has offered significant as- sistance in the successful restoration of functional and aesthetic disorders through the virtual planning of the operation. In this paper we present a case of oral cancer whose resection and reconstruction with fibula free flap were done after digital design and under the guidance of special cutting guides. To our knowledge, this case of computer-guided reconstruction with FFF represents the first description of such a technique for mandibular reconstruction in the available greek medico-dental literature.