Single pararectus approach combined with three-dimensional guidance for the treatment of acetabular fracture.

Background: Surgery for acetabular fractures involving both columns is difficult and traumatic, making it necessary to explore a minimally invasive and accurate surgical method. Methods: This retrospective case-control study analyzed the clinical data of 34 patients and divided them into two groups: a control group (9 males and 8 females) and a research group (11 males and 6 females) with acetabular fractures involving the anterior and posterior columns. All patients were placed in the supine position via the pararectus approach. A three-dimensional (3D) guide was placed at the position where the posterior column screw was inserted in the second window, and a posterior column screw was placed percutaneously on the medial side of the iliac spine in the research group. The operation time, intraoperative blood loss, and fracture union time of the two groups were recorded. Pelvic radiographs and computed tomography (CT) scans were routinely performed before and after surgery to evaluate reduction and fixation. Residual gap and step displacement were measured using a standardized CT-based method after the surgery. Hip mobility was assessed according to the modified Merle, d'Aubigné, and Postel criteria. Results: All patients were followed up for 6-30 (16.941±6.571) months. The operation times of the two groups were 126 [interquartile range (IQR), 95-133] min (control group) and 110 (IQR, 85-124) min (research group), the intraoperative blood losses were 430 (IQR, 290-550) mL (control group) and 380 (IQR, 260-500) mL (research group). All patients achieved bone healing, with a union time of 15 (IQR, 12-17) weeks (control group) and 13 (IQR, 11.5-15) weeks (research group). According to the standardized CT-based method, the reduction after surgery was acceptable in 13 (control group) and 14 (research group) of these patients (defined as a gap <5 mm or a step-off <1 mm), and the anatomical reduction rates were 76.47% and 82.35%, respectively. Conclusions: The use of a single pararectus approach combined with 3D guide-assisted percutaneous anterograde posterior column screws can shorten the operation time and place effective posterior column screws precisely with minimal invasiveness. At the same time, the acetabular reduction and functional recovery are satisfactory, and there are fewer postoperative complications, which makes this procedure an ideal surgical option.

Guided Endodontic Surgery: A Narrative Review.

Background and objectives: Endodontic surgery has evolved over the last two decades. The use of state-of-the-art guided endodontic surgical procedures produces a predictable outcome in the healing of lesions of endodontic origin. The main objective of this review paper is to define and characterize guided surgical endodontics as well as its benefits and drawbacks by reviewing the most recent relevant scientific literature. Methods: A literature search was conducted using multiple databases comprising of MEDLINE (via PubMed), EMBASE, and Web of Science. The terms used for the search were 'guided endodontics', 'surgical endodontics', and 'endodontic microsurgery'. Results: In total, 1152 articles were obtained from the analysis of the databases. Unrelated articles from the available full text of 388 articles were excluded. A total of 45 studies were finally included in the review. Conclusions: Surgical-guided endodontics is a relatively new area of study that is still maturing. It has many applications such as root canal access and localization, microsurgical endodontics, endodontic retreatment, and glass fiber post removal. Additionally, it does not matter how experienced the operator is; the procedure can be completed for the patient in less time and provides greater accuracy and safety than conventional endodontics.

Multiple Meningioma Resection by Bilateral Extended Rostrotentorial Craniotomy with a 3D-Print Guide in a Cat.

A 13-year-old castrated male domestic shorthair cat was referred for the surgical removal of multiple meningiomas. The cat experienced generalized tonic-clonic seizures, altered mentation, mild proprioceptive ataxia, and circling. Magnetic resonance imaging (MRI) revealed two round, solitary, well-delineated, space-occupying lesions suggestive of multiple meningiomas in the right frontal and occipital lobes. Before surgery, patient-specific three-dimensional (3D) printed models and guides were produced using a 3D program based on MRI and computed tomography (CT), and a rehearsal surgery was performed. With a 3D guide to find the location of the craniotomy lines, bilateral extended rostrotentorial craniotomy allowed en bloc resection of multiple meningiomas. The bone fragment was replaced and secured to the skull with a craniofacial plate and screws with an artificial dura. All of the surgical steps were performed without complications. The preoperative presenting signs were resolved by the time of follow-up examinations 2 weeks after surgery. Twelve months after the removal of the multiple meningiomas, the cat survived without further neurological progression. For the resection of multiple meningiomas, surgery can result in large bone defects and risk of massive hemorrhage. For this challenging surgery, patient-specific 3D models and guides can be effective for accurate and safe craniotomies.

3D printing guide plate for accurate hemicortical bone tumor resection in metaphysis of distal femoral: a technical note.

BACKGROUND: Surgical resection and reconstruction for low-grade bone sarcoma in the metaphysis of the distal femur remain challenging. We hypothesized that 3D printing osteotomy guide plate could assist to accurately resect the tumor lesion and save the joint function. METHODS: From January 2017 to August 2019, five patients diagnosed with low-grade bone sarcoma in the metaphysis of the distal femur were treated with hemicortical resection using 3D printing guide plate. Autologous bone graft was inactivated in a high-temperature water bath and re-implanted in situ fixed with plate and screw. Patients were followed up from 17 to 33 months. The Musculoskeletal Tumor Society Score was used to evaluate the joint function. X-ray was used to evaluate the bone union. RESULTS: One patient was paracorticular osteosarcoma, and four cases had highly differentiated chondrosarcoma. All cases were involved in the metaphysis of the distal femur. Patients were followed up from 13 to 33 months, with an average of 23.6 months. There was neither post-operation infection, internal fixation loosening, nor fracture occurrence in any of the patients. The Musculoskeletal Tumor Society Score averaged at 28.1, while the International Society of Limb Salvage imaging score examination averaged 89.8%. CONCLUSIONS: Here, we demonstrate that the 3D printing osteotomy guide plate-assisted hemicortical bone resection is a beneficial strategy to effectively resect the primary low-grade malignant bone tumors in the metaphysis of the distal femur and retained satisfied joint function.

[Comparative study between 3D guide plate assisted and free-hand insertion of anterior cervical transpedicular screw].

OBJECTIVE: To compare accuracy of anterior cervical pedicle screws between assist of rapid prototyping 3D guide plate and free-hand insertion, and evaluate the safety of two methods. METHODS: Eight adult cervical cadaver specimens after formaldehyde immersion, including 4 males and 4 females, aged 32 to 65(40.3±5.6) years old. After X-ray examination to exclude bone damage and deformity, 4 of them (3D guide plate group) randomly selected were for CT scan to obtain DICOM format data, and the data was imported into Mimics software for model, designed the ideal entry point and nail path for anterior cervicaltranspedicular screw (ATPS). After obtaining the personalized guide plate of the nail channel, it was exported as STL data, and the individual guide plate was printed by rapid prototyping and 3D printing technology. In turn, with the assistance of 3D guide plates, one-to-one personalized ATPS screws were placed on the four lower cervical cadaver specimens. Another 4 (free-hand group) lower cervical cadaver specimens were implanted with ATPS screws using free-hand technique. All specimens were performed CT thin-layer scanning and three-dimensional reconstruction after operation. The Tomasino method was used to evaluate the safety of the screws on the CT cross-sectional and sagittal images, to determine whether there was a cortical puncture of the lower and inner edges of the pedicle. According to the CT rating results, gradeⅠandⅡwere safe, and grade Ⅲ- Ⅴ were dangerous.And the accuracy of screws was recorded and analyzed between two groups. RESULTS: Two screws were inserted in each segment from C3 to C7 in 8 adult cadavers. A total of 80 screws were inserted, 40 in the 3D guide plate group, and 40 in the free-hand group. The Tomasino screw rating method was used to evaluate the safety of screw, 21 screws were gradeⅠ, 14 screws were gradeⅡ, 3 screws were grade Ⅲ, 1 screw was grade Ⅳ, 2 screws were grade Ⅴ in 3D guide plate group, while 14 screws were gradeⅠ, 8 screws were gradeⅡ, 8 screws were grade Ⅲ, 6 screws were grade Ⅳ, 2 screws were grade Ⅴ in free-hand group. The safety rate of 3D guide plate group was 87.5%, and 55.0% of the free hand group (χ2=8.7, P=0.003). CONCLUSION: The 3D printing rapid prototyping guide plate assisted insertion of the anterior cervical pedicle screw can significantly improve the accuracy and safety, and provide a theoretical basis for further clinical application.