Custom Prosthesis Research Articles

Surgical reconstruction of the sternum following cardiac surgery complicated by mediastinitis—implantation of a custom-made sternal implant: a case report

: Mediastinitis represents an uncommon but potentially life-threatening complications following median sternotomy. There remains a lack of consensus regarding the optimal treatment option(s). Custom tridimensional titanium printing provides an effective method for construction of complex prothesis. We report the case of a 49-year-old female with previous sternal dehiscence and deep wound infection following coronary artery bypass grafts, necessitating sternectomy. A year later, she presented with chronic severe pain and audible crepitations of her ribs/clavicles. Lack of identification of a mechanical cause, poor localisation and suboptimal medical pain management culminated in the consideration for a novel approach for sternal reconstruction. By way of bridging the final placement of the titanium prothesis, the patient underwent placement of a methyl methacrylate spacer. The surgical approach involved the removal of the temporary spacer, with tissue samples taken to guide post-operative antimicrobial therapy. Concurrently, the reaming, irrigation and aspiration technique of bone marrow harvesting, for seeding of the central web structure of the implant, was employed under fluoroscopic guidance. Following adequate dissection under the pectoral muscle, and debridement of the anterior chest wall, final placement of the prothesis was made via bicortical fixation to the ribs. Finally, the mobilised pectoral muscles were sutured medially and fixed to the previously placed rectus abdominis flap. Three-dimensional printing of a custom prosthesis offers a novel and effective approach to full reconstruction; maintaining pulmonary mechanics and stability of the anterior chest wall

Profile of Custom Ocular Prosthesis Users in a Tertiary Eye Care Centre in Nepal

Objective: To analyze the profile of custom ocular prosthesis users in Nepal. Methodology: This was a retrospective study done at Drishti Eye Care System, Nepal from January 2019 to June 2019. One eyed subject who used custom prosthesis for minimum of 6 months or above of any age group were recruited in the study. Information regarding laterality, cause of loss of eye, reason for opting ocular prosthesis and source of information regarding ocular prostheses were collected from the participants. A set of questions were asked to the participants through telephonic interview after the duration of 3 to 6 months wear of ocular prosthesis to collect information on any symptoms after the wear. Results: Mean age of subjects in the study was 31.35±16.59 years (range 1.5 years – 78 years), 46.7% (n=14) were male and 53.3% (n=16) were female. Trauma was the most common cause of loss of the eye in 43.3% (n=13), followed by congenital loss and eye infections in 16.7% (n=5). 43.3% (n=13) of the subjects had lost their right eye and 56.7% (n=17) subjects had lost their left eye. 33.3% (n=10) of the subjects didn’t have any symptoms with the use of prosthesis. Milder form of symptoms like small appearance, mild discharge and pain were major complaints after the wear. Conclusion: There is a need of best prosthetic rehabilitation for the anophthalmic patients.

Automated Noncontact Facial Topography Mapping, 3-Dimensional Printing, and Silicone Casting of Orbital Prosthesis

A proof-of-concept workflow study for the fabrication of custom orbital exenteration prostheses via automated noncontact scanning, 3D printing, and silicone casting. Noncomparative, interventional case series. Setting: Single-center institutional study. StudyPopulation: Three patients who have discontinued wearing of the ocularist-made exenteration prosthesis due to altered fit, discoloration, or material degradation. InterventionProcedure: A digital representation of the exenteration socket and contralateral periocular region was captured through noncontact facial topography mapping. Digital construction of the anterior prosthesis surface was based on the mirrored image of the contralateral side, and the posterior surface contour was based on orbital cavity geometry. The anterior and posterior surface details were digitally merged. A 2-piece mold was designed and produced in a 3D printer. Colorimetry was used to create a custom blend of pigments for incorporation into the Shore 40 silicone elastomer to generate a prosthesis that approximates the patient's skin tone. MainOutcomeMeasures: Prosthesis symmetry, skin tone match, comfort of wear, and appearance. The first copy of every 3D-printed orbital prosthesis using this fabrication workflow produced good symmetry, color match, and prosthesis fit. In one case, the recontoured second copy with improved prosthesis edge-to-skin interface was made without the patient present. A noncontact 3D scanning, computer-aided design, 3D printing, and silicone casting for fabrication of orbital prosthesis was developed and validated. This production workflow has the potential to provide an efficient, standardized, reproducible exenteration prosthesis and to overcome the principal barriers to an affordable custom prosthesis worldwide: access and cost.

Three-dimensional-printed customized prosthesis for pubic defect: prosthesis design and surgical techniques

BackgroundThis study is to describe the detailed design and surgical techniques of three-dimensional (3D)-printed customized prosthesis for pubic bone defect.Patients and methodsFive patients under type III resections were included in this study. Based on radiography data, 3D pelvic model was established and virtual surgery was simulated. Detailed anatomy data were measured including the size and arc of normal pubis, the size of residual bone in acetabular side. Different fixation ways were considered according to shape of defect. After features modification and porous structure design, prostheses were fabricated. The osteotomy guides and plastic models were used during surgery.ResultOf 5 cases, the prostheses consist of the type with stem (3, 60%) and the type without stem (2, 40%). Mean follow-up period was 13.6 months (range, 8-24 months). For partial pubis removed cases, the mean length and width of narrowest part of normal superior pubis were 13.19 mm (range, 12.51-14.12 mm) and 7.80 mm (range, 7.18-8.26 mm) respectively. Mean arc of normal pubis was 2.71 rad (range, 2.66-2.73 rad). For the entire pubis resection cases, the mean diameter of narrowest parts and length of normal superior pubis were 11.52 mm (range, 11.13-11.91 mm) and 64.78 mm (range, 63.46-66.09 mm), while the diameter of narrowest part and length of normal inferior pubis were 7.37 mm (range, 7.20-7.54 mm) and 86.43 mm (range, 84.28-88.57 mm). Mean length and arc of intramedullary stem was 20 mm (range, 18-21 mm) and 2.7 rad. Mean screw holes number was 6.3 (range, 6-7) while ultimate screws number in surgeries was 4.3 (range, 4-5). Porous structure with 600-μm-pore size and 70% porosity was applied in parts of contact with residual bone.Conclusion3D-printed customized prostheses could be a feasible option to reconstruct bone defect after type III resection. The design of 3D-printed customized prostheses is a multi-step process which is based on strict anatomic measurement.

Numerical Study of a Customized Transtibial Prosthesis Based on an Analytical Design under a Flex-Foot® Variflex® Architecture

This work addresses the design, analysis, and validation of a transtibial custom prosthesis. The methodology consists of the usage of videometry to analyze angular relationships between joints, moments, and reaction forces in the human gait cycle. The customized geometric model of the proposed prosthesis was defined by considering healthy feet for the initial design. The prosthesis model was developed by considering the Flex-Foot® Variflex® architecture on a design basis. By means of the analytical method, the size and material of the final model were calculated. The behavior of the prosthesis was evaluated analytically by a curved elements analysis and the Castigliano theorem, and numerically by the Finite Element Method (FEM). The outcome shows the differences between the analytical and numerical methods for the final prosthesis design, with an error rate no greater than 6.5%.

Results of the Total Hip Arthroplasty Using 3D Printing Technology

Objectives: To study the value of 3D printing of custom THA femoral prostheses with conventional femoral prostheses in total hip arthroplasty for severe hip deformity. Methods: Total hip arthroplasty was used in the treatment of 107 severe hip joint deformity cases from June 2018 to June 2019. Fifty-six patients received conventional hip replacement stems and 51 patients received a custom 3D printed hip replacement stem designed to address their proximal deformity and leg length discrepancy. The operation time, intraoperative blood loss, postoperative weight-bearing time, Harris score before and after the operation, complications after surgery and the main angle measurement of compared to their contralateral hip were evaluated to determine the short-term efficacy of 3D printed total hip replacement femoral prosthesis compared to the common total hip replacement femoral prosthesis. Results: A total of 107 patients were followed up for an average of 12 months. The use of 3D printing technology in the preoperative design and custom prosthesis fabrication was associated with shortened operation time, less intraoperative blood loss, quicker time to postoperative full weight-bearing, and improved the Harris score in 1 year after the operation compared to conventional total hip replacement stem (p<.05). Our results revealed that there was a significant reduction in the femoral anteversion with a value of 13.06 ± 1.93 degrees (mean ± SD) in the custom prosthesis group compared to the conventional hip replacement group. However, there was no significant difference in neck-shaft angle, acetabular angle, and Sharp angle between both groups (p>.05). Conclusion: 3D printing technology created a virtual and realistic simulation, and personalized operation plan for patients with severe hip deformity, which was helpful for surgical treatment. The anatomical characteristics of patients with complex deformities were better addressed using the 3D printed femoral component and resulting in better patient outcomes and provided a new option for surgeons to manage these difficult cases.

Reconstructive surgery of the skullcap through pmma custom prosthesis after decompressive craniectomies.

INTRODUCTION: Decompressive craniectomy is indicated for the treatment of intracranial hypertension in cases of serious traumatic brain injury. This surgery results in a bizarre appearance, as if "part of the head" had been. After regression of cerebral edema and when the patient is in good clinical condition, the reconstruction of the skull is indicated. Reconstruction of the skull can be performed with autologous bone or with alloplastic materials. This study sought to present the experience of the author with skull reconstructions using custom PMMA prostheses.
 METHODS: In between 2014 and 2015, fourteen patients with previous (longer than 6 months) decompressive craniectomies were selected after Neurosurgery medical clearance and underwent skull reconstruction with customized PMMA prototyped prostheses. Signs and symptoms of syndrome of the trephined, computed tomography, and aesthetic appearance of the patients were analyzed preoperatively and at 6 months after reconstruction.
 RESULTS: All patients presented with improved symptomatology, aesthetic improvement and expansion of the brain after surgery.
 CONCLUSION: Reconstruction of the skull with customized prototyped PMMA prostheses improved the signs and symptoms and the aesthetic appearance in all 14 patients of this series. The use of prototypes to customize cranial prostheses facilitates the operative technique and enables patients to develop a nearly normal cranial contour.

Preclinical Strength Checking for Artificial Pelvic Prosthesis under Multi-activities - A Case Study

Customized prostheses are normally employed to reconstruct the biomechanics of the pelvis after resection due to tumors or accidents. The objective of this study is to evaluate the biomechanics of the pelvis under different daily activities and to establish a functional evaluation methodology for the customized prostheses. For this purposes, finite element model of a healthy pelvis as well as a reconstructed pelvic model after type II+III resection were built for biomechanical study. The biomechanical performance of the healthy and reconstructed pelvic model was studied under routine activities including standing, knee bending, sitting down, standing up, walking, stair descent and stair ascent. Subsequently, the strength and stability of the prosthesis were evaluated under these activities. Results showed that, for the heathy pelvic model, the stresses were mainly concentrated around the upper part of the sacrum and the sacroiliac joint undergoing different activities, and the maximum stress occurred during stair ascent. As for the reconstructed pelvis, the stress distribution and the tendency of the maximum stress variation predicted for the bone part during all the activities were similar to those of the natural pelvic model, which indicated that the load transferring function of the reconstructed pelvis could be restored by the prosthesis. Moreover, the predicted maximum von Mises stress of the screws and prosthesis was below the fatigue strength of the 3D printed Ti-6Al-4V, which indicated the prosthesis can provide a reliable mechanical performance after implantation.

Customizing a Cryolite Glass Prosthetic Eye.

In Germany, Austria, and Switzerland, over 90% of ocularists still manufacture customized prostheses using cryolite glass from Thuringia. The present manuscript demonstrates this long-forgotten technique in detail. This manuscript shows some major advantages of manufacturing prosthetic eyes using cryolite glass in comparison to poly(methyl methacrylate) (PMMA). These advantages include a lighter weight of the prosthesis, higher levels of patient satisfaction, and only one appointment necessary for the customized manufacturing. Potential risk of breakage seems not to be a critical disadvantage for glass prosthetic eye wearers. However, in some patients, manufacturing a well-fitting prosthetic eye is not possible or reasonable due to anophthalmic socket complications such as post nucleation socket syndrome, scarred fornices, or an orbital implant exposure. This article gives ophthalmologists a better insight into ocularistic care in order to improve the essential interprofessional collaboration between ocularists and ophthalmologists.

Clinical Applications of 3-Dimensional Printing Technology in Hip Joint.

Three‐dimensional (3D) printing is a digital rapid prototyping technology based on a discrete and heap‐forming principle. We identified 53 articles from PubMed by searching “Hip” and “Printing, Three‐Dimensional”; 52 of the articles were published from 2015 onwards and were, therefore, initially considered and discussed. Clinical application of the 3D printing technique in the hip joint mainly includes three aspects: a 3D‐printed bony 1:1 scale model, a custom prosthesis, and patient‐specific instruments (PSI). Compared with 2‐dimensional image, the shape of bone can be obtained more directly from a 1:1 scale model, which may be beneficial for preoperative evaluation and surgical planning. Custom prostheses can be devised on the basis of radiological images, to not only eliminate the fissure between the prosthesis and the patient's bone but also potentially resulting in the 3D‐printed prosthesis functioning better. As an alternative support to intraoperative computer navigation, PSI can anchor to a specially appointed position on the patient's bone to make accurate bone cuts during surgery following a precise design preoperatively. The 3D printing technique could improve the surgeon's efficiency in the operating room, shorten operative times, and reduce exposure to radiation. Well known for its customization, 3D printing technology presents new potential for treating complex hip joint disease.

The application of rapid prototyping in facial surgeries: a series of case studies

<p class="Body"><strong>Aim:</strong> to report on the applicability of biomodels obtained from computerized tomography (CT) images through the technique of stereolithography (SLA) and three-dimensional printing (3DP), in the clinical case reports of patients who underwent surgeries involving dentoskeletal deformity, oral pathology and oral and maxillofacial trauma. <strong>Metodology: </strong> Clinical case 01 deals with fractures in the orbital and zygomatic arch region that required reconstruction and correction of diplopia, by means of CT images, using the technique of three-dimensional printing through SLA, generating a mirrored biomodel for surgical planning and the making of customized prostheses. In clinical case 02, by means of CT images, a biomodel utilizing the 3DP technique showed the total area invaded by invasive ameloblastoma, making it possible to plan the osteotomy with maximum preservation of the adjacent tissue and prior modeling of the plate. In clinical case 03, rapid prototyping technology (RP) was used to make customized prostheses for temporomandibular articulation, with the goal of correcting a serious idiopathic pathology provoking the resorption of the right and left condyles. <strong>Discussion: </strong>Complex cases require the team to have recourse to technology for the implementation of the procedures, in order to offer excellent quality treatment to the patient, in addition to facilitating surgical planning and permitting the construction of customized prostheses. <strong>Conclusion:</strong> that rapid prototyping for the acquisition of biomodels is an important auxiliary tool for the surgical team. </p>

Custom Hip Stem Additive Prototyping Using Smart Materials

Although a standardized hip joint prosthesis is a quick and easy solution to repair most diseases related to the hip joint, it never satisfies the patient s personal needs due to the uniqueness of the human anatomy. Femoral hip stem geometry is one of the factors that have an important impact on prosthesis lifespan or the revision surgery frequency that occurs due to postoperative complications, such as impingement or dislocation after THR (Total Hip Replacement). In this sense, the development of a custom hip stem prosthesis starting from a standardized femoral stem can bring benefits to the patient in time, being able to reduce the failure percentage of THR. The purpose of this article is the development of a custom prosthesis based on patient s CT (Computer Tomographic) scans in order to be 3D printed with biocompatible materials, being able to serve as a study model in both engineering and medicine. Also this study represents a first step in understanding how to apply the unique distribution of mechanical properties in human bone, in order to manufacture a hip prothesis that can mimic them.

Design and finite element analysis of customized pelvic prosthesis

To introduce the design of customized pelvic prosthesis, to evaluate the biomechanical property under three load conditions of customized pelvic prosthesis under three load cinditions. A titanium alloy prosthesis for reconstruction of pelvic tumors was designed by CAD software. The strength and stiffness of the custom prosthesis under static and slow gait conditions were analyzed and evaluated by finite element method. The results of the finite element analysis suggested that the maximum von Mises stress in the pelvic under three load conditions were 39.0, 202.8 and 42.4 MPa; the maximum displacement were 0.199, 0.766 and 0.847 mm. The maximum von Mises stress in the prosthesis under three load conditions were 62.3, 318 and 468 MPa. The maximum Von Mises stress in the Ti-alloy prosthesis and pelvic was far smaller than the yield strength of Ti-alloy. The study can design the size and shape of prosthesis accurately according to patient's condition. The finite element method can reduce the bone stress level and fracture risk, prolong the service life of prostheses, and ensure the safety and stability of the postoperative patients under normal gait.

A new methodology for design and manufacturing of a customized silicone partial foot prosthesis using indirect additive manufacturing.

The production of customized prostheses for the foot and ankle still relies on slow and laborious steps of the traditional plaster molding fabrication techniques. Additive manufacturing techniques where three-dimensional objects can be constructed directly based on the object's computer-aided-design data in a layerwise manner has opened the door to new opportunities for manufacturing of novel and personalized medical devices. The purpose of the present study was to develop a new methodology for design and manufacturing of a customized silicone partial foot prosthesis via an indirect additive manufacturing process. Furthermore, the biomechanics of gait of a subject with partial foot amputation wearing the custom silicone foot prosthesis manufactured by the indirect additive manufacturing was characterized, in comparison with a matched healthy participant. This study has confirmed the possibility of producing silicone partial foot prosthesis by indirect additive manufacturing procedure. The amputated subject reported total comfort using the custom prosthesis during walking, as well as cosmetic advantages. The prosthesis restored the foot geometry and normalized many of gait characteristics. The findings presented here contribute to introduce a proper understanding of biomechanics of walking after wearing silicone partial foot prosthesis and are useful for prosthetists and rehabilitation therapists when treating patients after partial foot amputation.

Custom Nasal Septum Prosthesis Fabricated from a 3D-Printed Working Model: A Clinical Report.

This clinical report describes the treatment of a 47-year-old female patient with a nasal septum perforation. The treatment used a 2-piece magnetic custom prosthesis fabricated from a 3D-printed model. By using an existing medical CT scan to generate the printed working model, the number of clinical appointments was reduced. The workflow expanded the purpose of the radiologic images from simply diagnostic to include the prosthetic aspect of treatment.

Computational analysis of customized cruciate retaining total knee arthroplasty restoration of native knee joint biomechanics.

The purpose of this study was to verify if customized prosthesis better preserves the native knee joint kinematics and provides lower contact stress on the polyethylene (PE) insert owing to the wider bone preservation than that of standard off-the-shelf prosthesis in posterior cruciate-retaining type total knee arthroplasty (TKA). Validated finite element (FE) models for were developed to evaluate the knee joint kinematics and contact stress on the PE insert after TKA with customized and standard off-the-shelf (OTS) prostheses as well as in normal healthy knee through FE analysis under dynamic loading conditions. The contact stresses on the customized prosthesis decreased by 18% and 8% under gait cycle loading conditions, and 24% and 9% under deep-knee-bend loading conditions, in the medial and lateral sides of the PE insert, respectively, compared with the standard OTS prosthesis. The anterior-posterior translation and internal-external (IE) rotation in customized TKA were more similar to native knee joint behaviors compared with standard OTS TKA under gait loading conditions. The difference from normal knee kinematics was lower for femoral rollback and IE rotation in customized TKA than in standard OTS TKA in the deep-knee-bend condition. In general, customized prostheses achieve kinematics that are close to those of the native healthy knee joint and have better contact stresses than standard OTS prostheses in gait and deep-knee-bend loading conditions.

Comparison of Proximal Femoral Geometry and Risk Factors between Femoral Neck Fractures and Femoral Intertrochanteric Fractures in an Elderly Chinese Population.

Background:Few studies have investigated the differences in proximal femoral geometry and risk factors between patients with different types of hip fracture, especially in elderly Chinese. This study aimed to assess the differences in proximal femoral geometry parameters between patients with femoral neck fractures and patients with intertrochanteric fractures to provide guidance for individualized customized prosthesis and accurate reconstruction of proximal femurs in elderly Chinese patients.Methods:We retrospectively studied the electronic medical records of 198 elderly patients over 65 years of age who were admitted to the orthopedic department with hip fractures between January 2017 and December 2017 in The Third Hospital, Hebei Medical University. Age, fracture site, gender, and proximal femoral geometry parameters (neck shaft angle [NSA], center edge angle [CEA], femoral head diameter [FHD], femoral neck diameter [FND], femoral neck axial length [FNAL], hip axial length [HAL], and femoral shaft diameter [FSD]) were recorded. Student's t-test was used to compare the continuous variables, Chi-square test was used to analyze categorical variables, and multiple logistic stepwise regression analysis was used to evaluate the influencing factors of hip fracture type.Results:Statistically significant differences in NSA (137.63 ± 4.56° vs. 132.07 ± 4.17°, t = 1.598, P < 0.001), CEA (37.62 ± 6.77° vs. 43.11 ± 7.09°, t = 5.597, P < 0.001), FND (35.21 ± 3.25 mm vs. 34.09 ± 3.82 mm, t = 2.233, P = 0.027), and FNAL (99.30 ± 7.91 mm vs. 103.58 ± 8.39 mm, t = 3.715, P < 0.001) were found between the femoral neck fracture group and femoral intertrochanteric fracture group. FHD, FND, FSD, HAL, and FNAL were different between sexes (all P < 0.001). The greater NSA was the risk factor for femoral neck fractures (odds ratio [OR]: 0.70, P < 0.001), greater CEA and longer FNAL were risk factors for femoral intertrochanteric fractures (OR: 1.15, 1.17, all P < 0.001), and greater FND was a protective factor for femoral intertrochanteric fractures (OR: 0.74, P < 0.001).Conclusions:We demonstrate differences in geometric morphological parameters of the proximal femur in different hip fracture types, as well as an effect of sex. These differences should be considered in the selection of prostheses for fracture internal fixation and hip replacements. These data could help guide the design of individualized customized prostheses and improve the accurate reconstruction of the proximal femur for elderly Chinese hip fracture patients.

Long-term outcomes after cosmetic customized prostheses and dermis fat graft in congenital anophthalmia: a retrospective multicentre study.

To evaluate long-term outcomes of progressively enlarging cosmetic customized prostheses (CCP) early after birth followed by dermis fat graft (DFG), as a strategy of socket rehabilitation in children with clinical congenital anophthalmia (CCA). Twenty patients with unilateral and two patients with bilateral CCA were enrolled. All patients were treated by inserting a CCP at the time of their first assessment which was then enlarged. Subsequently they underwent DFG. Differences in vertical palpebral aperture (VPA) and horizontal palpebral length (HPL), between affected and unaffected sides, were recorded at the first CCP fitting as well as before and after DFG. Satisfaction with cosmetic results, prosthetic retention, and complications rate were assessed. Magnetic resonance imaging of the orbit was performed in all patients before and after surgery. A significant decrease in the difference between the normal and the anophthalmic side of both PA and HPL was found over follow-up. Both VPA and HPL differences decreased by 47.6% (10.5 mm, range 1-28 mm) and by 7.1% (5.8 mm, range 0-18 mm), respectively. Satisfaction in terms of cosmetic outcomes proved to be very positive, being "very satisfied" for families and "satisfied" for physicians. Excellent retention of prostheses was observed in all cases. A rehabilitating strategy combining early CCP and further DFG proved to be a valuable approach in children with CCA, offering significant benefits in terms of socket expansion, prosthetic retention, psychological impact, and cosmetic outcomes.

Experimental investigation of the mechanical performances of titanium cranial prostheses manufactured by super plastic forming and single-point incremental forming

In the present work, sheet-forming processes, i.e. super plastic forming and single-point incremental forming, have been adopted for the manufacturing of custom prostheses, instead of subtractive and additive techniques that are time- and cost-consuming for a single-piece production. Regarding concerns of the material, three different titanium alloys were used: pure titanium and two grades of the alloy Ti-6Al-4V (the standard one and the extra low interstitial one). Since no standard protocol exists to assess the mechanical performance of cranial implants, an experimental procedure has been designed and used in this work for producing polymethylmethacrylate supports, on which the cranial prostheses were firmly connected and subjected to impact puncture tests (drop tests). An experimental campaign could thus be conducted to investigate the effect on the mechanical response of (a) the titanium alloy, (b) the initial blank thickness and (c) the manufacturing process. Drop tests, carried out according to the proposed procedure, have shown no failure of the prostheses, neither in the area of the impact nor in the anchoring region and have revealed that, irrespective of the adopted manufacturing process, which does not alter the material, the amount of energy absorbed by the implants is always larger than 70%.

Finite Element Analysis of the Pelvis after Customized Prosthesis Reconstruction

Custom-made pelvic prostheses are normally employed to reconstruct the biomechanics of the pelvis for improving patient’s life quality. However, due to the large demand of biomechanical performance around the pelvic system, the customized prosthesis needs to be studied for its strength and stability. A hemi-pelvic finite element model, including a custom-made prosthesis and the surrounded main ligaments, was created to study the strength and stability of the system. Based on the developed finite element model, the relationship between the pre-stress of the screws and the biomechanical performance of the reconstructed pelvis was investigated. Results indicate that the pre-stress should not exceed 1000 N during surgery in order to prevent fatigue fractures from happening to screws. Moreover, four screws were removed from the pelvic system without affecting the fixing stability of the system, which provide surgical guidance for surgeons in terms of safety and fixation.