Three-dimensional Surgical Planning Research Articles

Computer-assisted three-dimensional individualized extreme liver resection for hepatoblastoma in proximity to the major liver vasculature.

The management of hepatoblastoma (HB) becomes challenging when the tumor remains in close proximity to the major liver vasculature (PMV) even after a full course of neoadjuvant chemotherapy (NAC). In such cases, extreme liver resection can be considered a potential option. To explore whether computer-assisted three-dimensional individualized extreme liver resection is safe and feasible for children with HB who still have PMV after a full course of NAC. We retrospectively collected data from children with HB who underwent surgical resection at our center from June 2013 to June 2023. We then analyzed the detailed clinical and three-dimensional characteristics of children with HB who still had PMV after a full course of NAC. Sixty-seven children diagnosed with HB underwent surgical resection. The age at diagnosis was 21.4 ± 18.8 months, and 40 boys and 27 girls were included. Fifty-nine (88.1%) patients had a single tumor, 39 (58.2%) of which was located in the right lobe of the liver. A total of 47 patients (70.1%) had PRE-TEXT III or IV. Thirty-nine patients (58.2%) underwent delayed resection. After a full course of NAC, 16 patients still had close PMV (within 1 cm in two patients, touching in 11 patients, compressing in four patients, and showing tumor thrombus in three patients). There were 6 patients of tumors in the middle lobe of the liver, and four of those patients exhibited liver anatomy variations. These 16 children underwent extreme liver resection after comprehensive preoperative evaluation. Intraoperative procedures were performed according to the preoperative plan, and the operations were successfully performed. Currently, the 3-year event-free survival of 67 children with HB is 88%. Among the 16 children who underwent extreme liver resection, three experienced recurrence, and one died due to multiple metastases. Extreme liver resection for HB that is still in close PMV after a full course of NAC is both safe and feasible. This approach not only reduces the necessity for liver transplantation but also results in a favorable prognosis. Individualized three-dimensional surgical planning is beneficial for accurate and complete resection of HB, particularly for assessing vascular involvement, remnant liver volume and anatomical variations.

WITHDRAWN: Comparison of the application value of 3D printed osteotomy guide plate and artificial intelligence 3D surgical planning in artificial total knee arthroplasty

In this study, we aimed to assess the impact of personalized 3D printing osteotomy guide plates and artificial intelligence (AI) three-dimensional surgical planning in total knee arthroplasty (TKA) for knee osteoarthritis. The clinical data of 60 knee osteoarthritis patients were collected, with 30 undergoing personalized 3D printing osteotomy guide plate-assisted TKA (3D-TKA) and 30 undergoing AI 3D surgical planning-assisted TKA (AI-TKA). Surgical outcomes were comprehensively evaluated, including operation time, intraoperative blood loss, postoperative drainage, hospitalization duration, surgical angles (HKA, FTC, FFC), pain scores (VAS), and Hospital for Special Surgery Scores (HSS).Significant differences emerged between the two groups, favoring the 3D-TKA approach. Notably, the 3D-TKA group exhibited a shorter operation time (81.4±8.9 min vs. 72.9±10.0 min), reduced intraoperative blood loss (160.1±24.3 ml vs. 174.7±25.7 ml), lower postoperative drainage (199.5±29.6 ml vs. 223.8±29.2 ml), and a shorter hospital stay (7.7±1.3 d vs. 6.8±1.6 d) (P<0.05). In the immediate postoperative period, the 3D-TKA group demonstrated significantly lower VAS scores (5.4±0.6 vs. 6.2±1.2) (P<0.05). However, there were no significant differences in measured angle deviations, pain scores, and HSS scores at various time points between the groups (P>0.05).Collectively, both 3D-TKA and AI-TKA approaches yielded improved surgical outcomes and precision for treating knee osteoarthritis. While AI-TKA demonstrated advantages in terms of operation time and hospitalization duration, the 3D-TKA approach proved superior in reducing perioperative blood loss and early postoperative pain. These findings underscore the potential of advanced technological interventions to optimize surgical efficacy and patient outcomes in total knee arthroplasty.

Cross Sectional Analysis of Eurasian Skull Anatomy for 3D Cephalometry-Normative Data Reveal Four Different Skull Types.

The unsolved problem in three-dimensional surgical planning for patients with facial deformity, dysgnathia, or asymmetry is the lack of a normative database of "norm skulls" that can be used as treatment objectives. A study was conducted on 90 Eurasian persons (46 male and 44 female adults) for whom cone beam-computed tomography images were available. Inclusion criteria were adult patients with a skeletal Class I pattern, proper interincisal relationship with normal occlusion, the absence of an open bite both in the anterior and posterior region, and a normal and balanced facial appearance; patients with dysgnathia and malformations were excluded. A total of 18 landmarks were digitized and 3D cephalometric measurements were performed and analyzed by means of proportions calculated from the landmarks. Male and female skulls were analyzed, as well as subdivisions revealed by cluster analysis. The data showed that four subtypes of skulls were distinguishable with statistical significance (p < 0.05). A male and a female type subdivided in a brachiocephalic and dolichocephalic phenotype could be identified. For each type, a mean shape was calculated by a Procrustes transformation, which, in turn, was used to create four template skulls from a male and a female skull. This was accomplished by fitting the polygon models of the two skulls to each of the two subtypes based on the landmarks marked on them using a thin plate spline transformation. The normative data of the subtypes can individually serve as a guide for orthodontic surgery in the Eurasian population, which is especially helpful in 3D planning and the execution of craniofacial operations.

Accuracy of Soft Tissue Prediction in Skeletal Type III Relationship Using a Computer-Aided Three-Dimensional Surgical Simulation Planning Program

Using a computer-aided, three-dimensional surgical simulation planning program, soft-tissue planning can help achieve adequate facial esthetics and patient satisfaction after orthognathic surgery. This study aimed to assess the Simplant O&amp;O software’s soft tissue prediction accuracy. Fourteen skeletal type III patients who underwent orthognathic surgery by the same surgeons were included in this prospective study, and they were separated into two groups: the one-jaw (n = 5) and two-jaw (n = 9) groups. The software was used to analyze the preoperative (T0) and 4-month postoperative computed tomography data (T1), as well as intraoral scans. Data from cone-beam computed tomography and stereolithography from a scanned dental cast were used to reconstruct a composite skull model. Based on the presurgical CT data, the program generated a predicted soft tissue image (TP), which was then superimposed on the T1. The distances between seven T1 and TP landmarks were measured and evaluated using a one-sample t-test. In the one-jaw group, the mean error for all linear measurements was 1.73 ± 1.14 mm, whereas the mean error of the two-jaw group was 1.03 ± 0.83 mm, and both measurements were within clinically acceptable limits. Pronasele had the best correlation (mean error of 0.63 ± 0.45 mm) while soft tissue pogonion and soft tissue point B had the worst correlations (mean error of 2.87 ± 2.22 mm and 1.31 ± 0.98 mm, respectively). Even though there were some limitations, it was possible to conclude that the ability to accurately predict soft tissue changes using Simplant O&amp;O for skeletal type III patients makes it adequate for use in clinical practice.

Clinical analysis of three-dimensional surgical planning system for guiding robot-assisted selective artery clamping partial nephrectomy in completely endophytic renal tumor

Objective: To examine the safety and feasibility of three-dimensional (3D) surgical planning system for guiding robot-assisted selective artery clamping partial nephrectomy (RASPN) in completely endophytic renal tumor. Methods: Clinical data of 32 patients who suffered from completely endophytic renal tumor and underwent RASPN associated with 3D surgical planning system in Department of Urology, Sun Yat-Sen University Cancer Center from November 2018 to August 2021 were analyzed retrospectively. There were 21 males and 11 females, with the age (M (IQR)] of 45.0 (17.5) years (range: 30 to 68 years). Fifteen tumors were located on the left and 17 on the right. Maximum tumor diameter, R.E.N.A.L. Score and preoperative estimated glomerular filtration rate (eGFR) were 27.5 (13.0) mm (range: 14 to 50 mm), 10.0 (1.8) (range: 7 to 11), and 105.5 (15.7) ml·min-1·(1.73 m2)-1 (range: 71.1 to 124.8 ml·min-1·(1.73 m2)-1), respectively. The 3D reconstruction before RASPN was performed in all patients to formulate surgical planning, mainly including stereo localization of renal mass, confirmation of tumor feeding artery, and injury prediction of collecting system or vessel via "2 mm distance method" defined as probable damage of renal pelvis/calyx and artery/vein when these tissues were less than 2 mm away from tumor. Results: Totally 32 patients successfully underwent RASPN guided by 3D surgical planning system, without conversion to open operation or radical nephrectomy. Rapid location of tumor and selective clamping of artery were achieved in all cases and no one encountered global ischemia, with branch occlusion time of 24.5 (15.4) min (range: 12 to 60 min) and coincidence rate of 95.0% (57/60) between planned and actual clamping vessels. The sensitivity and specificity of 2 mm distance method for predicting the injury of collecting system were 13/15 and 17/17, respectively. The operating time of 185 (48) minuetes (range: 76 to 295 minutes) and estimated blood loss of 200 (350) ml (range: 20 to 800 ml) were observed, without intraoperative transfusion case. There was one patient performed with renal vein repair. Clavien-Dindo postoperative grade Ⅱ and Ⅲa bleeding complications occurred in 2 cases, and no postoperative urinary fistula was found. The length of hospitalization was 3 (0) days (range: 2 to 10 days). The pathological diagnosis demonstrated 4 chromophobe cell carcinomas and 2 angiomyolipomas, besides 26 clear cell carcinomas including one positive surgical margin. The postoperative latest eGFR was 103.9(18.5) ml·min-1·(1.73 m2)-1 (range: 75.8 to 122.3 ml·min-1·(1.73 m2)-1) and no tumor recurrence or metastasis was detected during the follow-up time of 15.4 (13.9) months (range: 3 to 35 months). Conclusion: For RASPN in completely endophytic renal tumor, 3D surgical planning system is contributed to determining mass position, defining tumor feeding artery, and predicting collecting system/vessel injury, which benefited precise tumor resection, postoperative renal function preservation, and perioperative urinary fistula and bleeding complication decrease.

Does the use of a "wrap" in three-dimensional surgical planning influence the bony margin status of benign and malignant neoplasms of the oral, head, and neck region? An initial investigation.

Three-dimensional surgical planning (3-DSP) is becoming commonplace in the management of benign and malignant disease for oral and maxillofacial surgery practice within the last decade. Surgeons utilize a virtual "wrap" to preoperatively delineate and define maxillofacial tumor resection margins. The investigators hypothesized that the use of a wrap is a predictable method to obtain negative bony margins. The investigators implemented a retrospective chart review. The sample was composed of patients over the age of 18 treated at John Peter Smith Health Network and Parkland/UT Southwestern Medical Center who obtained 3-DSP for the pathology of the head and neck, involving the bone, with a virtual wrap utilized for bony margins. The proportion of cases was calculated, descriptive statistics were reported, and binomial exact calculation was performed for confidence intervals. The primary variable analyzed was bony margin status on final histopathology, involved or uninvolved, based on the pathology report. The sample was composed of 39 cases, one of which was excluded due to aborting the preplanned 3-DSP. Of the 38 included cases, one had involved bony margin on final histopathology (2.6%; 95% confidence limits, 0.1%, 13.8%). There were 16 malignant cases (42%) and 22 benign cases (58%). When stratified by pathology, 1 out of the 16 malignant cases (6.3%; 95% confidence interval, 0.2%, 30%) and 0 out of the 22 benign cases (95% confidence interval, 0%, 15.4%) had an involved bony margin on final histopathology. The results of this preliminary study suggest three-dimensional surgical planning with wrap margins is a predictable method to obtain negative bony margins in benign and malignant disease of the maxillofacial complex. Further studies will focus on compiling prospective data to solidify the accuracy and predictability of using a wrap to obtain negative bony margins.

Stem size prediction in shoulder arthroplasty with preoperative 3D planning.

Three-dimensional surgical planning software provides virtual reconstructions of the shoulder with automated joint indices for a preoperative case assessment. The aim of this single center study was to evaluate the concordance between the preoperatively selected humeral components and the final implants used in shoulder arthroplasty. 129 cases who had undergone anatomic (n = 16) or reverse shoulder arthroplasty (n = 117) using the same type of uncemented short stem implant and were included for review in this study. The type of arthroplasty, stem size, stem inclination, tray-offset and liner-thickness were noted preoperatively and compared to the final implant specifications used in surgery. The type of arthroplasty matched the surgical plan in 99.2% of cases, as one case was converted from RSA to TSA. The concordance of planned to implanted stem size was 44.2% and the planned size was in range of one adjacent size in 87.6% of cases. Stem inclination in TSA matched the surgical plan in 50% of cases. Tray offset in RSA was predicted correctly in 65% and liner-thickness matched the surgical plan in 98.3% of cases. Despite a low degree of concordance of planned to implanted stem sizes of 44.2%, the choice of stem size was found to be in range of one adjacent size in 87.6% of cases. Further investigations of other contributing factors are necessary to increase the accuracy of the preoperative selection of humeral implants. level IV, retrospective case study.

Finite element modeling for biomechanical validation of three-dimensional digital surgical planning in periacetabular osteotomy

Finite element modeling for biomechanical validation of three-dimensional digital surgical planning in periacetabular osteotomy

Endodontic Microsurgery of Posterior Teeth with the Assistance of Dynamic Navigation Technology: A Report of Three Cases

When nonsurgical endodontic treatment fails, surgical treatment is an alternative approach for treating periapical disease. However, endodontic microsurgery (EMS), particularly in anatomically challenging areas, such as the posterior teeth, is a skill-sensitive task that can present a unique set of challenges for the surgeon. In recent years, digital guidance technology has been applied more frequently in dentistry. Dynamic navigation (DN) is a pioneering technology that uses an optical positioning device controlled by a sophisticated computerized interface and dedicated three-dimensional surgical path planning software program. This technique has also recently been introduced in the field of EMS to improve accuracy and avoid related complications. This case report presents a novel approach to DN-assisted EMS and describes its application in posterior teeth. After undergoing DN-assisted EMS, all patients were completely asymptomatic at the follow-up visit. Radiographic examinations performed immediately and 3–9 months after EMS revealed that the root resection was performed accurately without complications. The DN technique has been proven to be a feasible, predictable, and time-saving system for assisting EMS in cases requiring treatment in anatomically challenging areas, such as in the posterior teeth.

Three-dimensional surgical planning and clinical evaluation of the efficacy of distal tibial tuberosity high tibial osteotomy in obese patients with varus knee osteoarthritis

PurposeHigh tibial osteotomy (HTO) is an effective surgical treatment for varus knee osteoarthritis. However, obese patients require reinforced internal fixation materials to prevent internal fixation fractures and hardware failure after osteotomy. Therefore, the purpose of our study is to evaluate the clinical efficacy of distal tibial tuberosity high tibial osteotomy (DTT-HTO) using the new patented π-shaped plate in obese patients with varus knee osteoarthritis. MethodThirty-four obese patients (39 knees) with varus knee osteoarthritis who underwent DTT-HTO with the π-shaped plate and second-look arthroscopy when implant removal occurred from September 2017 to June 2020 were retrospectively reviewed. Three-dimensional surgical planning using DTT-HTO on the knees is performed. There were 9 males and 25 females, with body mass index (BMI) values ranging from 30.3 to 38.5 kg/m2 and ages ranging from 50 to 75 years old. The radiological assessment was performed with the femora tibial angle (FTA) and the weight-bearing line ratio (WBLR). The clinical outcomes were evaluated by the Hospital for Special Surgery (HSS) knee score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The status of the cartilage was evaluated by the International Cartilage Repair Society (ICRS) grading system. ResultsAll patients were followed up for 18-30 months. The FTA significantly changed from 181.68±1.68.preoperatively to171.29±1.51.at the last follow-up (P<0.001). The WBLR significantly increased from 16.85±2.20 to 55.41±2.46% from before surgery to the last follow-up after surgery (P<0.001). The HSS score significantly improved from 56.65±5.27 preoperatively to 68.79±2.61, 77.82±2.15, and 86.12±2.78 at the 6-month, 12-month, and last follow-up after surgery (P<0.001). The WOMAC score significantly decreased from 105.47±3.89 preoperatively to 80.50±4.20, 71.44±4.65, and 52.44±3.14 at the 6-month, 12-month, and last follow-up after surgery (P<0.001). During implant removal, no internal fixation fractures occurred in any patient. The articular cartilage grade in the medial compartment of the knee were significantly higher in the second arthroscopy than in the first arthroscopy, according to the ICRS grading system (P<0.001). The articular cartilage grade in the lateral compartment of the knee showed no statistical differences from the first- to the second-look arthroscopy (P>0.05). ConclusionThere are no correlation between BMI and postoperative outcomes. DTT-HTO shows yield excellent clinical results in obese patients with varus knee osteoarthritis. It can be recommended to be used for the heavy patients.

Application of Mixed Reality in Medical Training and Surgical Planning Focused on Minimally Invasive Surgery

Introduction:Medical training is a long and demanding process, in which the first stages are usually based on two-dimensional, static, and unrealistic content. Conversely, advances in preoperative imaging have made it an essential part of any successful surgical procedure. However, access to this information often requires the support of an assistant and may compromise sterility in the surgical process. Herein, we present two solutions based on mixed reality that aim to improve both training and planning in minimally invasive surgery.Materials and Methods:Applications were developed for the use of the Microsoft HoloLens device. The urology training application provided access to a variety of anatomical and surgical training contents. Expert urological surgeons completed a questionnaire to evaluate its use. The surgical planning solution was used during laparoscopic renal tumorectomy in an experimental model and video-assisted right upper lobectomy in an adult patient. Surgeons reported their experience using this preoperative planning tool for surgery.Results:The solution developed for medical training was considered a useful tool for training in urological anatomy, facilitating the translation of this knowledge to clinical practice. Regarding the solution developed for surgical planning, it allowed surgeons to access the patient’s clinical information in real-time, such as preoperative imaging studies, three-dimensional surgical planning models, or medical history, facilitating the surgical approach. The surgeon’s view through the mixed reality device was shared with the rest of the surgical team.Conclusions:The mixed reality-based solution for medical training facilitates the transfer of knowledge into clinical practice. The preoperative planning tool for surgery provides real-time access to essential patient information without losing the sterility of the surgical field. However, further studies are needed to comprehensively validate its clinical application.

Novel Automated Three-Dimensional Surgical Planning Tool and Magnetic Resonance Imaging/Ultrasound Fusion Technology to Perform Nanoparticle Ablation and Cryoablation of the Prostate for Focal Therapy

Purpose: Although MRI/ultrasound fusion has been primarily used to assist in the diagnosis of prostate cancer, this technology can also be used to focally treat localized prostate cancer. We present one case of nanoparticle-directed ablation and two cases of cryoablation to focally treat prostate tumors. Patients and Methods: Three patients underwent MRI/ultrasound fusion transperineal prostate biopsies to confirm low- to intermediate-risk prostate cancer. The MRI lesions correlated with the biopsy-proven disease. Pelvic MRI segmentation was performed with DynaCAD 5.0 workstation. The MRI lesion including a 6 to 10 mm margin, prostate, bladder, urethra, urethral sphincter, rectum, and pubic bone were segmented. MRI/ultrasound fusion was performed with the novel Philips UroNav 4.0 system. Lesions were treated with focal nanoparticle ablation or focal cryoablation. Results: A 69-year-old man with a right posterior medial peripheral zone lesion positive for Gleason grade group (GG)3 cancer was treated with focal nanoparticle ablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 94% of the 6 to 10 mm margin at the end of the case. A 68-year-old man with a left anterior fibromuscular stroma lesion positive for Gleason GG2 cancer and a 71-year-old man with a right peripheral zone posterior lateral lesion positive for Gleason GG1 cancer were treated with focal cryoablation. The UroNav 4.0 system reported 100% ablation of the segmented tumor and 82% of the 6 to 10 mm margin at the end of the case. Conclusion: Observation of the prostate tumor(s), surrounding critical structures, and pelvis in three dimensions (3D), along with the anticipated ablation zone, is one of the challenges of pelvic surgery and percutaneous ablation. The DynaCAD 5.0 Urology system can create an auto-segmented 3D rendering of critical structures and the tumor(s), as well as observation and quantification of the anticipated ablation coverage, to facilitate preoperative planning of needle placement. ClinicalTrials.gov nos.: NCT02680535 and NCT04656678.

Does the Use of a Wrap in Three-Dimensional Surgical Planning Influence the Bony Margin Status of Benign and Malignant Neoplasms of the Oral, Head and Neck Region? An Initial Investigation

<h3>Purpose</h3> Three-dimensional surgical planning (3-DSP) is becoming commonplace in the management of benign and malignant disease for oral and maxillofacial surgery practice within the last decade.¹ In pathologic resections of the head and neck cysts and tumors in particular, a virtual wrap is used to delineate the tumor resection margin. However, there has yet to be a study in regard to the accuracy of this wrap and its effect on bony margin status. This study aims to discuss our experiences with the use of wraps created with 3-DSP and explore the accuracy of the wrap for margin status. We hypothesize that the use of a wrap is a predictable method to obtain negative bony margins. Furthermore, we explore the emerging challenges in the use of this technology specific to pathologic resection margins. <h3>Methods</h3> This is a retrospective chart review. The study included patients over the age of 18 (range, 18-99) treated at 2 centers, John Peter Smith Health Network Oral and Maxillofacial Surgery and Parkland/UTSW Oral and Maxillofacial Surgery. We included patients who obtained a 3-DSP for pathology of the head and neck involving the bone and who also obtained a virtual wrap for bony margins. There were no specific exclusion criteria. There were no exclusions due to racial, ethnic, or gender groups. Data accessed ranged from July 1, 2017, to May 1, 2020. Patient data were collected for processing via multilevel protected electronic health record system (Epic). Once the data were gathered, the identifiable link was destroyed and data were anonymized. Analysis was completed via Excel. <h3>Results</h3> There were 39 cases, but we excluded 1 that required intraoperative adjustment and thus did not follow preplanned case. One out of the 38 cases involved a bony margin (2.6%; 95% confidence interval, 0.1%, 13.8%). Table 1 defines the pathology. We classified SCC (squamous cell carcinoma) and low-grade osteosarcoma as malignant cases and the rest as benign. There were 16 malignant cases (42%) and 22 benign cases (58%). When stratified by pathology, 1 out of the 16 malignant cases (6.3%; 95% confidence interval, 0.2%, 30%) and 0 out of the 22 benign cases (95% confidence interval, 0%, 15.4%) had a positive margin. <h3>Conclusion</h3> Three-dimensional surgical planning with wrap margins is a predictable method to obtain negative bony margins in benign and malignant disease of the maxillofacial complex. The surgeon must be prudent to ensure accurate margin delineation by engineers before simulated wrap creation or resection.

A 3D-CT Analysis of Femoral Symmetry-Surgical Implications.

Background: Mirroring the image of the affected side is a widely used technique for surgical planning in orthopedic surgery, especially for fractures and custom-made prostheses. Our objective is to evaluate the three-dimensional symmetry of the femurs using finite element analysis and manual alignment. Methods: Using the computed tomography of 15 patients without lower limb pathology, 30 3D biomodels of their femurs were obtained. The error obtained through image manipulation was calculated and broken down into a rendering error and a manual overlay error. The Hausdorff–Besicovitch method was applied to obtain the total asymmetry. The manipulation error was theb subtracted from it to obtain the intrapersonal asymmetry. Results: The mean intrapersonal asymmetry was 0.93 mm. It was obtained by subtracting the error derived from rendering and alignment of 0.59 mm (SD 0.17 mm) from the overall mean error of 1.52 mm (SD 1.45). Conclusions: Intrapersonal femoral asymmetry is low enough to use the mirror image of the healthy side as a reference for three-dimensional surgical planning. This type of planning is especially useful in deformity surgery when the objective of the surgery is not to restore only one specific parameter but to obtain a general functional morphology when a healthy contralateral femur is available.

Iatrogenic Displaced Maxillary Third Molar Tooth

Minor to major complications may occur during the third molar extraction but should be optimized. Surgeons should know how to diagnose the case and manage the complications. We hereby report one of the rare complications of upper third molar extraction; iatrogenic displacement in infratemporal space. We emphasized hence on management of such technically sensitive case using 3D virtual surgical planning. The use of computer-assisted three-dimensional surgical planning to reconstruct the tooth in its localized position and orientation makes the operation more accurate, more convenient, and avoids damage to vital structures.

Reduction of scapulohumeral subluxation with posterior augmented glenoid implants in anatomic total shoulder arthroplasty: Short-term 3D comparison between pre- and post-operative CT

BackgroundFailure rates in anatomic total shoulder arthroplasty (aTSA) are higher in case of asymmetric glenoid bone loss secondary to posterior wear, and in persistent static posterior subluxation of the humeral head (PSH). HypothesisThis study aimed to test the hypothesis that the combined use of posterior augmented glenoid (PAG) implants with three-dimensional (3D) surgical planning and patient-specific instrumentation (PSI) guides helps reduce short-term PSH after aTSA in patients with type B2-B3 glenoids. Patients and methodsWe included nine consecutive patients with primary glenohumeral osteoarthritis and type B2 or B3 glenoids, who underwent aTSA with cemented keeled PAG implants (posterior augments of 15, 25, or 35 degrees). All patients underwent preoperative shoulder computed tomography (CT) scans, with 3D surgical planning coupled to PSI at the time of surgery. Postoperative shoulder CT scans were performed at an average of 14 weeks (range, 10-21 weeks). Scapulohumeral subluxation and glenoid version and inclination were measured in 3D, on both pre- and post-operative CT scans, using the same reliable quantitative method. ResultsThere was a significant decrease in scapulohumeral subluxation from 49±12% preoperatively to 22±17% postoperatively (p=0.0039), with a large effect size (Cohen's d=1.89). Preoperative glenoid version was corrected from −17.3±9.4 degrees to −5.2±7.5 degrees postoperatively. The absolute difference between the postoperative and surgically planned version and inclination was 5.4±3.6 degrees and 3.3±2.0 degrees, respectively. DiscussionThe combined use of PAG implants with 3D preoperative planning and PSI results in a significant decrease in short-term PSH and glenoid version in patients with asymmetric posterior glenoid wear. We suggest that such implants should not be limited to posterior augmentation, because glenoid deficiency can also be observed in other glenoid sectors. Level of evidenceIV, Basic science study.

Total joint reconstruction using computer-assisted surgery with stock prostheses for a patient with bilateral TMJ ankylosis

BackgroundsThe purpose of this study is to discuss the total joint reconstruction surgery for a patient with recurrent ankylosis in bilateral temporomandibular joints (TMJs) using three-dimensional (3D) virtual surgical planning, computer-aided manufacturing (CAD/CAM)-fabricated surgical guides, and stock TMJ prostheses.Case presentationA 66-year-old female patient, who had a history of multiple TMJ surgeries, complained of severe difficulty in eating and trismus. The 3D virtual surgery was performed with a virtual surgery software (FACEGIDE, MegaGen implant, Daegu, South Korea). After confirmation of the location of the upper margin for resection of the root of the zygoma and the lower margin for resection of the ankylosed condyle, and the position of the fossa and condyle components of stock TMJ prosthesis (Biomet, Jacksonville, FL, USA), the surgical guides were fabricated with CAD/CAM technology. Under general anesthesia, osteotomy and placement of the stock TMJ prosthesis (Biomet) were carried out according to the surgical planning. At 2 months after the operation, the patient was able to open her mouth up to 30 mm without complication.ConclusionFor a patient who has recurrent ankylosis in bilateral TMJs, total joint reconstruction surgery using 3D virtual surgical planning, CAD/CAM-fabricated surgical guides, and stock TMJ prostheses may be an effective surgical treatment option.

3D planning and surgical navigation of clavicle osteosynthesis using adaptable patient-specific instruments

BackgroundPreoperative three-dimensional planning and intraoperative navigation by patient-specific instruments is a promising method for the exact correction of bone deformities. Nevertheless, disadvantages of current concepts are the missing options of adapting the surgical plan intraoperatively. By providing the surgeons with a controlled length adjustment through the patient-specific instruments, the application area can usefully be expanded in the treatment of clavicle osteosyntheses.MethodsIn three cases, preoperative three-dimensional surgical planning with the intraoperative use of patient-specific instruments was applied. The computer-assisted assessments of clavicle deformities, the preoperative plan, and the design of patient-specific instruments were created on the basis of computed tomography data. Reduction guides for restoring length and rotation according to the mirrored healthy contralateral side were enhanced with adaptable length adjustment functions. The screw thread of the reduction guides enabled temporary distraction of the clavicle fracture fragments and a controlled compression of the optionally used interposed bone block between clavicle fragments.ResultsNavigated clavicle osteosyntheses by enhanced patient-specific instruments was executed uneventful in all three cases. The surgeon was able to adapt clavicle length in a planned axis intraoperatively as clinically desired.ConclusionComputer-assisted planning of clavicle osteosynthesis and surgical navigation with additional adaptable patient-specific instruments can usefully expand the previous application areas. By using guided length adjustments, the fragments and optionally the graft can be compressed along a planned axis as desired to ensure optimal bone healing.Level of evidenceBasic science study, Surgical technique

Computer-assisted anteverting eccentric rotational acetabular osteotomy for recurrent posterior dislocation associated with acetabular retroversion: a case report

BackgroundAcetabular retroversion is a rotatory abnormality of the entire hemipelvis that includes anterior over-coverage and posterior deficiency of the acetabulum, and is associated with pincer-type femoroacetabular impingement and posterior hip instability. Acetabular retroversion is thought to cause posterior dislocation of the hip in athletes due to both the pincer-type femoroacetabular impingement and posterior hip instability.Case presentationA 26-year-old Japanese man had acetabular retroversion that induced recurrent posterior dislocation of his hip due to excessive hip flexion while wakeboarding. We performed anteverting eccentric rotational acetabular osteotomy using preoperative three-dimensional planning and an intraoperative computerized navigation system. Our patient was able to return to sports activities 1 year postoperatively.ConclusionsBoth preoperative three-dimensional surgical planning software and an intraoperative navigation system can provide a highly accurate map for this complicated surgery that simultaneously improves the pincer-type femoroacetabular impingement and posterior deficiency of the acetabulum.

Three-dimensional soft tissue prediction in orthognathic surgery: a clinical comparison of Dolphin, ProPlan CMF, and probabilistic finite element modelling

Three-dimensional surgical planning is used widely in orthognathic surgery. Although numerous computer programs exist, the accuracy of soft tissue prediction remains uncertain. The purpose of this study was to compare the prediction accuracy of Dolphin, ProPlan CMF, and a probabilistic finite element method (PFEM). Seven patients (mean age 18years; five female) who had undergone Le Fort I osteotomy with preoperative and 1-year postoperative cone beam computed tomography (CBCT) were included. The three programs were used for soft tissue prediction using planned and postoperative maxillary position, and these were compared to postoperative CBCT. Accurate predictions were obtained with each program, indicated by root mean square distances: RMSDolphin=1.8±0.8mm, RMSProPlan=1.2±0.4mm, and RMSPFEM=1.3±0.4mm. Dolphin utilizes a landmark-based algorithm allowing for patient-specific bone-to-soft tissue ratios, which works well for cephalometric radiographs but has limited three-dimensional accuracy, whilst ProPlan and PFEM provide better three-dimensional predictions with continuous displacements. Patient or population-specific material properties can be defined in PFEM, while no soft tissue parameters are adjustable in ProPlan. Important clinical considerations are the topological differences between predictions due to the three algorithms, the non-negligible influence of the mismatch between planned and postoperative maxillary position, and the learning curve associated with sophisticated programs like PFEM.