Better preoperative planning improves liver resection outcomes

Since the advent of liver resection as a treatment option for benign and malignant liver diseases, liver resections have continued to become safer with most centers reporting low morbidity and mortality. Gradual improvements in outcomes over the last decade have largely been due to improvement in surgical techniques including the more routine use of laparoscopy and advances in perioperative care.

Printed Three-dimensional Anatomic Templates for Virtual Preoperative Planning Before Reconstruction of Old Pelvic Injuries： Initial Results

Background：Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy,difficult-to-access surgical sites,and the relatively low incidence of such cases.Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture.The goal of this study was to assess the use of three-dimensional （3D） printing techniques for surgical management of old pelvic fractures.Methods：First,16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data.Next,nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models.The pelvic injuries were all type C,and the average time from injury to reconstruction was 11 weeks （range：8-17 weeks）.The workflow consisted of.：（1） Printing patient-specific bone models based on preoperative computed tomography （CT） scans,（2） virtual fracture reduction using the printed 3D anatomic template,（3） virtual fracture fixation using Kirschner wires,and （4） preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation.These models aided communication between surgical team members during the procedure.This technique was validated by comparing the preoperative planning to the intraoperative procedure.Results：The accuracy of the 3D printed models was within specification.Production of a model from standard CT DICOM data took 7 hours （range：6-9 hours）.Preoperative planning using the 3D printed models was feasible in all cases.Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases.The patients were followed for 3-29 months （median：5 months）.The fracture healing time was 9-17 weeks （mean：l0 weeks）.No delayed incision healing,wound infection,or nonunions occurred.The results were excellent in two cases,good in five,and poor in two based on the Majeed score.Conclusions：The 3D printing planning technique for pelvic surgery was successfully integrated into a clinical workflow to improve patient-specific preoperative planning by providing a visual and haptic model of the injury and allowing patient-specific adaptation of each osteosynthesis implant to the virtually reduced pelvis.

Computer-assisted preoperative planning for proximal humeral fractures by minimally invasive plate osteosynthesis

Background Accurate and precise preoperative planning can provide information instrumental for performing less invasive articular fracture surgery. The purpose of this study was to determine that computer-assisted preoperative planning （CAPP） has the potential to improve efficiency and time in the operating room. Methods Sixty-four patients with proximal humeral fractures were treated using locking plates by minimally invasive plate osteosynthesis （MIPO） with CAPP. The time needed for virtual segmentation, reduction, and fixation of the fracture fragments were recorded. Intra and interobserver reliabilities were analyzed using the intraclass correlation coefficient. The clinical function was analyzed using Constant Score and radiology. Results The mean total time required for CAPP of two-part, three-part, and four-part proximal humeral fractures were （13.63±1.38） minutes, （23.14±2.18） minutes, and （39.61±3.01） minutes, respectively. The intra and interobserver reliabilities for all variables were high, ranging from 0.785 to 0.992. The mean operation time was （50.1±6.7） minutes. Fifty- two patients were followed up with an average time of 34.2 months. The mean Constant Score of the injury side was （82.5 ± 9.9）. Three of the fifty-two patients had four complications. Conclusion The application of CAPP was efficient and reliable, and provided excellent clinical and radiographic outcomes for the treatment of proximal humerus fractures by MIPO.

Preoperative imaging in staghorn calculi, planning and decision making in management of staghorn calculi

Objective:Staghorn calculi present a particular and challenging entity of stone morphology.Treatment is associated with lower stone-free rates and higher complication rates compared to non-staghorn stones.In this review we looked for the most relevant data on preoperative imaging and access planning to help decision making for percutaneous surgery with this complex condition.Methods:We conducted a PubMed search of publications in the past 2 decades that include relevant information on the planning for management of staghorn stones.Non-contrast computerized tomography(NCCT)is indeed the standard imaging tool for percutaneous nephrolithotomy(PCNL);additional tools such as three-dimensional computed tomography(CT)reconstruction of the staghorn calculus may help plan access in complex cases.Ultrasound guided percutaneous access may be considered for staghorn stones when planning upper pole access in kidney malposition or complex intrarenal anatomy or with complex body habitus.Wideband doppler ultrasound and real-time virtual sonography can assist.New technologies to improve kidney access such as Uro Dyna-CT or electromagnetic sensor have been reported,but have not shown utilization in staghorn cases.Staghorn morphometry-based prediction algorithms may predict the number of tract(s)and stage(s)for PCNL monotherapy.Lower pole access can be equally effective as upper pole when planning for staghorn and complex stones,with significantly less complications rate;Stone-Tract length-Obstruction-Number of involved calyces-Essence of stone density(STONE)nephrolithometry seems to be the best system to predict outcomes of PCNL in staghorn cases.There is a growing trend of endoscopic combined intrarenal surgery(ECIRS)in concordance with PCNL to treat larger stones.Conservative management of staghorn calculi is an undesired option,but can be an alternative for a carefully selected group of high-risk patients.Conclusion:Staghorn stones may lead to deterioration of renal function and life-threatening urosepsis.This entity should be managed aggressively with planning ahead for surgery using the different tools available as the cornerstone for a successful outcome.

Three-dimensional visualization and virtual reality simulation role in hepatic surgery:Further research warranted

Artificial intelligence(AI)is the study of algorithms that enable machines to analyze and execute cognitive activities including problem solving,object and word recognition,reduce the inevitable errors to improve the diagnostic accuracy,and decision-making.Hepatobiliary procedures are technically complex and the use of AI in perioperative management can improve patient outcomes as discussed below.Three-dimensional(3D)reconstruction of images obtained via ultrasound,computed tomography scan or magnetic resonance imaging,can help surgeons better visualize the surgical sites with added depth perception.Preoperative 3D planning is associated with lesser operative time and intraoperative complications.Also,a more accurate assessment is noted,which leads to fewer operative complications.Images can be converted into physical models with 3D printing technology,which can be of educational value to students and trainees.3D images can be combined to provide 3D visualization,which is used for preoperative navigation,allowing for more precise localization of tumors and vessels.Nevertheless,AI enables surgeons to provide better,personalized care for each patient.

Anthropometric method for estimating component sizes in total hip arthroplasty

BACKGROUND Preoperative templating is essential in total hip arthroplasty(THA)as it not only helps to facilitate the correct implant type and size but also determines the postoperative biomechanics.Templating is also increasingly important from a medicolegal perspective and recommended in the British Orthopaedic Association Guide to Good Practice.Although templating has become increasingly digitised,there are no simple anthropometric models to predict implant sizes in the absence of digital methods.AIM To assess the accuracy of using an easily obtainable measurement(shoe size)to predict component sizes in THA compared with digital templating.METHODS Digital radiographs from a cohort of 102 patients(40 male,62 female)who had undergone uncemented or hybrid THA at a single centre were retrospectively templated to desired cup and stem sizes using TraumaCad■.We compared the templated size to the actual size of the implant and assessed if there was any correlation with the patient’s shoe size.RESULTS Statistically significant positive correlations were observed between:shoe size and templated cup size(ρ=0.92,P<0.001);shoe size with implanted cup size(ρ=0.71,P<0.001);shoe size and templated stem size(ρ=0.87,P<0.001);and shoe size with implanted stem size(ρ=0.57,P<0.001).Templated and implanted acetabular cup sizes were positively correlated(ρ=0.76,P<0.001)and were exact in 43.1%cases;80.4% of implanted cup sizes were within 1 size(+/-2 mm)of the template and 100% within 2 sizes(+/-4 mm).Positive correlation was also demonstrated between templated and implanted femoral stem sizes(ρ=0.69,P<0.001)and were exact in 52.6% cases;92.6% were within 1 size of the template and 98% within 2 sizes.CONCLUSION This study has shown there to be a significant positive correlation between shoe size and templated size.Anthropometric measurements are easily obtainable and can be used to predict uncemented component sizes in the absence of digital methods.

Preoperative virtual reduction method for pelvic fractures based on statistical shape models and partial surface data

Virtual reduction is crucial for successful and accurate reduction of pelvic fractures.Various methods have been proposed in this regard.However,not all of them are applicable to every pelvic fracture.Among these methods,the efficiency and accuracy of the method based on statistical shape models in clinical applications require further improvement.This study proposes a virtual reduction method for pelvic fractures that uses statistical shape models and partial surface data of a broken pelvis.Simulated fracture and clinical case experiments were conducted to validate the accuracy and effectiveness of the proposed method.The simulated fracture experiments yielded an average error of 1.57±0.39 mm and a maximum error of 12.82±3.54 mm.The virtual reduction procedure takes approximately 40 s.Based on three clinical case experiments,the proposed method achieves an acceptable level of accuracy compared with manual reduction by a surgeon.The proposed method offers the advantages of shorter virtual reduction times and satisfactory reduction accuracy.In the future,it will be integrated into the preoperative planning system for pelvic fracture reduction,thereby improving patient outcomes.