Usability testing of a novel interlocking three-dimensional miniplate for mandibular angle fractures.

BACKGROUND: We developed a novel interlocking three-dimensional (3D) miniplate design with an adjustable configuration. As this device is new, surgeons must become familiar with its application. This study evaluated the usability and learning curves associated with the novel interlocking 3D miniplate for mandibular fracture fixation. METHODS: The study participants, nine plastic surgeons, were asked to apply an interlocking 3D miniplate and a standard miniplate to polyurethane mandible models. The participants had completed the Basic Craniomaxillofacial Osteosynthesis course during residency and had operated on craniomaxillofacial fractures within the past 5 years. They were instructed to place the interlocking 3D miniplate three times and the standard miniplate once. We assessed the time required for implant placement, the comfort level of the surgeons, and the biomechanical stability of the plates. Biomechanical testing was conducted by subjecting the mandible to forces ranging from 10 to 90 N and the displacement was measured. RESULTS: The results indicate increasing comfort with each attempt at placing the interlocking 3D miniplate, with a significant difference between the first and third attempts. Additionally, a reduction in application time was noted with repeated attempts, suggesting improved efficiency. Biomechanical tests showed comparable stability between the tested plates. CONCLUSION: Multiple attempts at applying the interlocking 3D miniplate resulted in increased comfort and reduced application time. These findings indicate that, despite its novelty, the interlocking 3D miniplate is relatively straightforward to apply and has a short learning curve. However, surgeons must have specific qualifications to ensure proper training and minimize errors during placement.

Novel Design of Interlocking 3-Dimensional Miniplate in Mandibular Angle Fractures: An In Vitro Study.

The evolution of osteosynthesis has led to the development of novel miniplate designs, including 3-dimensional (3D) miniplates, which offer improved biomechanical stability. However, mandible fractures resulting from the high impact have a complex fracture configuration. Hence, the authors developed interlocking 3D miniplate to overcome the difficulty in miniplate and screw placement to avoid critical anatomic structures, that is, dental roots and nerve, while still providing stability for the fracture fragments. The interlocking 3D miniplates can be formed according to the specific needs by adjusting the horizontal and vertical cross struts configuration. This study describes a design process of interlocking 3D miniplates and evaluates biomechanical performance compared to standard miniplates. Finite element analysis was performed to evaluate the design's stress state using human and goat mandible models under various loading conditions. After the authors, established that our design was feasible for fabrication, the authors developed the prototype for biomechanical testing. Biomechanical testing was conducted on 10 goat mandibles to compare stability and displacement under various load between the interlocking 3D miniplate and the standard miniplate configuration. Biomechanical testing revealed reduced displacement in all directions with the interlocking 3D miniplate compared to the standard miniplate. Furthermore, there was a significant difference in all loads in the buccal-lingual displacement ( P <0.05). The novel interlocking 3D miniplate design shows an adequate ability to provide stability for fixation for mandibular fractures, as evidenced by finite element analysis and biomechanical testing. Further research is necessary to validate these findings and explore the clinical application of interlocking 3D miniplates in mandibular fracture management.

Scoliocorrector Fatma-UI for correction of adolescent idiopathic scoliosis: Development, effectivity, safety and functional outcome.

BACKGROUND: Adolescent idiopathic scoliosis remains a major problem due to its high incidence, high risk, and high cost. One of the aims of the management in scoliosis is to correct the deformity. Many techniques are available to correct scoliosis deformity; however, they are all far from ideal to achieve three-dimensional correction in scoliosis. AIM: To develop a set of tools named Scoliocorrector Fatma-UI (SCFUI) to aid three-dimensional correction and to evaluate the efficacy, safety, and functional outcome. METHODS: This study consists of two stages. In the first stage, we developed the SCFUI and tested it in finite element and biomechanical tests. The second stage was a single-blinded randomized clinical trial to evaluate the SCFUI compared to direct vertebral rotation (DVR). Forty-four subjects with adolescent idiopathic scoliosis were randomly allocated into the DVR group (n = 23) and SCFUI group (n = 21). Radiological, neurological, and functional outcome was compared between the groups. RESULTS: Finite element revealed the maximum stress of the SCFUI components to be between 31.2 - 252 MPa. Biomechanical analysis revealed the modulus elasticity of SCFUI was 9561324 ± 633277 MPa. Both groups showed improvement in Cobb angle and sagittal profile, however the rotation angle was lower in the SCFUI group (11.59 ± 7.46 vs 18.23 ± 6.39, P = 0.001). Neurological and functional outcome were comparable in both groups. CONCLUSION: We concluded that SCFUI developed in this study resulted in similar coronal and sagittal but better rotational correction compared to DVR. The safety and functional outcomes were also similar to DVR.

Radiological Outcomes of Reduction Surgery for Degenerative Lumbar Spondylolisthesis Using Long Arm Pedicle Screws.

Objective: Until now, the spondylolisthesis reduction technique has relied on posterior instrumentation using long arm pedicle screws. In this way, the segments will be brought into alignment with the other vertebrae with the pedicle mats being tightened. The aim of this study is to acknowledge whether reduction surgery for degenerative lumbar spondylolisthesis (DLS) using long arm pedicle screws is able to correct the listhesis and spinopelvic parameters. Methods: We carried out a retrospective study of patients with degenerative lumbar spondylolisthesis who went through reduction surgery using long arm pedicle screws in our institutions from January 2019 to March 2022. Preoperative and postoperative radiological outcomes consisting of listhesis and spinopelvic parameters were assessed. Results: We found a statistical difference between the magnitude of listhesis immediately after surgery and preoperatively (p<0.001), with a successful correction of 85.85%. There was significant decrease in the value of pelvic tilt (p=0.044) and increase in the value of sacral slope (p=0.008) after surgery. Conclusion: Reduction surgery using long arm pedicle screws for DLS was able to reduce the listhesis effectively up to 85.5%, and also to restore the parts of spinopelvic parameters, the pelvic tilt and sacral slope, approaching normal values.