Custom-made Prosthesis Research Articles

Three-dimension-printed custom-made prosthetic reconstructions: from revision surgery to oncologic reconstructions.

The use of custom-made 3D-printed prostheses for reconstruction of severe bone defects in selected cases is increasing. The aims of this study were to evaluate (1) the feasibility of surgical reconstruction with these prostheses in oncologic and non-oncologic settings and (2) the functional results, complications, and outcomes at short-term follow-up. We analyzed 13 prospectively collected patients treated between June 2016 and January 2018. Diagnoses were primary bone tumour (7 patients), metastasis (3 patients), and revision of total hip arthroplasty (3 patients). Pelvis was the most frequent site of reconstruction (7 cases). Functional results were assessed with MSTS score and complications according to Henderson et al. Statistical analysis was performed using Kaplan-Meier and log-rank test curves. At a mean follow-up of 13.7months (range, 6-26months), all patients except one were alive. Oncologic outcomes show seven patients NED (no evidence of disease), one NED after treatment of metastasis, one patient died of disease, and another one was alive with disease. Overall survival was 100% and 80% at one and twoyears, respectively. Seven complications occurred in five patients (38.5%). Survival to all complications was 62% at two years of follow-up. Functional outcome was good or excellent in all cases with a mean score of 80.3%. 3D-printed custom-made prostheses represent a promising reconstructive technique in musculoskeletal oncology and challenging revision surgery. Preliminary results were satisfactory. Further studies are needed to evaluate prosthetic design, fixation methods, and stability of the implants at long-term.

Latissimus dorsi rotational flap combined with a custom-made scapular prosthesis after oncological surgical resection: a report of two patients

BackgroundSarcomas that arise from the scapula or periscapular soft tissues often require a total scapulectomy. This often implies a large complex tissue defect that needs adequate reconstruction of both bone and soft tissue. Although various methods have been developed, no optimal procedure has emerged. Postoperative complications are common and functional recovery is not always satisfactory. This study aims to present a new surgical technique that combines a custom-made scapular prosthesis with a functional latissimus dorsi flap.Case presentationTwo patients diagnosed with malignant tumour of the scapular region were surgically treated after proper multidisciplinary evaluation. The first patient underwent the procedure as a first surgery, the second as revision surgery. The new technique comprises three surgical stages: excisional surgery with soft tissue resection and scapulectomy, bone reconstruction with custom-made prosthesis, and soft tissue reconstruction using a latissimus dorsi rotational flap overturned on the prosthesis. The goal is to set up a new functional unit combining an anatomically shaped implant (manufactured using latest three-dimensional printing technology) and a muscular flap, and to maintain the neurovascular supply. The patients were followed up to evaluate functional outcome and complications. Both patients were alive with no evidence of disease. Functional results were satisfactory and the Musculoskeletal Tumor Society scores were 87% and 63%, respectively. No surgical complications such as implant breakage, joint collapse, wound dehiscence, or infection were observed.ConclusionsThis new technique upgrades the role of the latissimus dorsi flap to a functional tool in combination with an anatomical, three-dimensionally printed, custom-made prosthesis, and provides adequate well-vascularized and healthy tissue to maximize the likelihood of successful limb salvage.

Titania-containing bioactive bone cement for total hip arthroplasty in dogs.

We developed a composite cement containing low-content bioactive titania fillers dispersed among specific polymethylmethacrylate (PMMA) polymers and investigated the mechanical properties and bioactivity of this titania bone cement (TBC) under load-bearing conditions in cemented total hip arthroplasty (THA) in adult female beagles. TBC and PMMA bone cement (PBC) were compared using custom-made prostheses. The dogs were killed 1, 3, 6, and 12 months postoperatively. The acetabulum was harvested to evaluate the osteoconductivity of the cement, whereas the femur was harvested for the push-out test and histological analyses. The compressive strength of TBC was significantly higher than that of PBC (p < 0.001), whereas the flexural and tensile strengths, as well as fracture toughness, were equivalent. The bonding strength values for TBC and PBC were 72.9 and 58.0 N/mm at 1 month, 69.4 and 57.2 N/mm at 3 months, 106.1 and 85.0 N/mm at 6 months, and 114.3 and 100.7 N/mm at 12 months, respectively. Histologically, TBC was in direct contact with bone without intervening with fibrous tissue over larger areas and newly formed bone was observed along the cement. The excellent mechanical properties and apparent bioactivity of this novel bone cement indicate its potential utility in clinical practice. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1238-1245, 2019.

First application of 3D design custom-made uncemented prosthetic stem for distal femoral cemented megaprosthesis revision

Objectives3D design, which is widely used in orthopedics, can be applied for precise distal femoral megaprosthetic revision. This research aimed to present and evaluate the design, perioperative management, and mid-term clinical outcomes of a 3D design custom-made uncemented prosthetic stem.MethodsBetween January 2014 and January 2016, seven patients received 3D design custom-made uncemented prosthetic stem revision at our institution. Clinical records and radiographs were evaluated retrospectively.ResultsThere were no hardware-related complications during the follow-up (average 24.3 months; range 24–48 months). The average Musculoskeletal Tumor Society (MSTS) score at the last follow-up after revision (27.7 points, range 25–28 points) was significantly higher than that before (16.0 points, range 13–18 points). In addition, the range of motion (ROM) of the affected knee, and the scores of pain, function, emotional acceptance, support, walking and gait all improved significantly. The antecurvature radian of the revision stem averaged at 3.6°. Of the seven patients, three received femoral stem revision and four received revision of the femoral stem and the femoral component; three of them used longer prostheses than the others. There were no significant differences in function between these two groups at the last follow-up after revision.ConclusionThe 3D design custom-made prosthesis is a typical precision medicine technology in oncologic orthopedics. Characterized by its individually and precisely designed uncemented stem, it offers an alternative option for distal femoral cemented prosthesis revision. Besides the 3D design itself, the perioperative management, especially the techniques for stem implantation, and long-term follow-up are also crucial.

Biomimetic 3D-printed custom-made prosthesis for anterior column reconstruction in the thoracolumbar spine: a tailored option following en bloc resection for spinal tumors : Preliminary results on a case-series of 13 patients.

Various techniques for anterior column reconstruction have been described after en bloc resection of spinal tumors. Limited evidence exists regarding one being superior to another. The purpose of this study is to evaluate 3D-printed vertebral bodies for spinal reconstruction after en bloc resection in the thoracolumbar spine. Prospective observational study on custom-made 3D-printed titanium reconstruction of vertebral bodies after en bloc resection for spinal tumor was conducted between November 2015 and June 2017. 3D-printed vertebral bodies were monitored for mechanical complications such as (1) migration, (2) subsidence into the adjacent vertebral bodies, and/or (3) breakage. Complications and related details were recorded. Thirteen patients (7 females and 6 males) were enrolled, and reconstruction of the anterior column was performed using custom-made 3D-printed titanium prosthesis after en bloc resection for spinal tumor (8 primary bone tumors and 5 solitary metastases). Subsidence into the adjacent vertebral bodies occurred in all patients at both proximal and distal bone-implant interfaces; however, it was clinically irrelevant (asymptomatic, and no consequences on posterior instrumentation), in 11 out of 12 patients (92%). In 1 patient (#4), severity of the subsidence led to revision of the construct. At an average 10-month follow-up (range 2-16), 1 implant was removed due to local recurrence of the disease and 1 was revisioned due to progressive distal junctional kyphosis. Preliminary results from this series suggest that 3D printing can be effectively used to produce custom-made prosthesis for anterior column reconstruction. These slides can be retrieved under Electronic Supplementary Material.

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.

3D interactive environment for the design of medical devices

The effectiveness of custom-made prostheses or orthoses heavily depends on the experience and skills of the personnel involved in their production. For complex devices, such as lower limb prosthesis, a conventional manual approach affects the process at the point that the result is frequently not acceptable at the first trial. The paper presents a computer-aided environment, named socket modelling assistant $$^{2}$$ (i.e., $$\hbox {SMA}^{2})$$ , to interactively design the socket of lower limb prosthesis by implementing a set of design rules extrapolated from the traditional development process. The new computer-aided environment has been implemented embracing a low-cost philosophy and using open source libraries to provide a solution affordable also by small orthopaedic laboratories. The system permits to modify and interact with the 3D model of residual limb to create the socket geometric model ready to be manufactured by means of additive manufacturing. $$\hbox {SMA}^{2}$$ embeds medical knowledge related to the device functioning, the conventional process and the way orthopaedic technicians work so that it can be much more reliable and repeatable compared to the conventional process, but still enough similar to it to be accepted by the involved personnel. In the paper, the new 3D design procedure is described in detail, from the acquisition of patient’s data to preliminary and customized modelling, and new geometric tools to perform context–related operations are shown. A case study is used to clarify the way the system works and to provide an example of the outcome.

Reconstruction of the hip after resection of periacetabular oncological lesions: a systematic review.

AimsReconstruction of the acetabulum after resection of a periacetabular malignancy is technically challenging and many different techniques have been used with varying success. Our aim was to prepare a systematic review of the literature dealing with these techniques in order to clarify the management, the rate of complications and the outcomes.Patients and MethodsA search of PubMed and MEDLINE was conducted for English language articles published between January 1990 and February 2017 with combinations of key search terms to identify studies dealing with periacetabular resection with reconstruction in patients with a malignancy. Studies in English that reported radiographic or clinical outcomes were included. Data collected from each study included: the number and type of reconstructions, the pathological diagnosis of the lesions, the mean age and follow-up, gender distribution, implant survivorship, complications, functional outcome, and mortality. The results from individual studies were combined for the general analysis, and then grouped according to the type of reconstruction. ResultsA total of 57 studies met the inclusion criteria and included 1700 patients. Most lesions were metastatic (41%), followed by chondrosarcoma (29%), osteosarcoma (10%), Ewing’s sarcoma (7%), and multiple myeloma (2%). The techniques of reconstruction were divided into seven types for analysis: those involving a Harrington reconstruction, a saddle prosthesis, an allograft and allograft prosthesis composite, a pasteurised autograft, a porous tantalum implant, a custom-made prosthesis and a modular hemipelvic reconstruction. The rate of complications was 50%, with infection (14%) and instability (8%) being the most common. Mortality data were available for 1427 patients (84%); 50% had died of disease progression, 23% were alive with disease, and 27% had no evidence of disease at a mean follow-up of 3.4 years (0 to 34). ConclusionBoth the rate of complications and mortality are high following resection of oncological periacetabular lesions and reconstruction. Many types of reconstruction have been used with unique challenges and complications for each technique. Newer prostheses, including custom-made prostheses and porous tantalum implants and augments, have shown promising early functional and radiographic outcomes. Cite this article: Bone Joint J 2018;100-B(1 Supple A):22–30.

On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

Temporomandibular joint replacement (TMJR) is a complex surgical procedure in which the artificial joints available must assure the anatomical reconstruction and guarantee a good range of the natural temporomandibular joint (TMJ) movements. With this aim, different types of TMJ prostheses, including the stock prosthetic system and custom‐made prostheses, are being currently implanted. Although temporomandibular joint replacements (TMJRs) are expected to accomplish their function during a number of years, they might actually fail and need to be replaced. This paper analyzes different design factors affecting the contact stress distributions within the TMJ prosthesis interface, which are consequently involved in their deterioration and final failure of the prosthetic device. With this purpose, a numerical model based on finite elements has been carried out in order to evaluate the stress states attained in different prosthesis configurations corresponding to general types of TMJ prostheses. On the other hand, the actual degradation of resected implants has been evaluated via optical microscopy. The linkage between the numerical simulations performed and experimental evidence allowed the authors to establish the different wear and damage mechanisms involved in the failure of stock TMJ prostheses. Indeed, the results obtained show that the contact stresses at the interface between the mandible and the glenoid fossa components play a key role in the failure process of the TMJR devices.

First-in-Australia Novel Sternal Reconstruction With Titanium-Printed Custom-made Prosthesis

Purpose: Description of first-in-Australia case of novel sternal reconstruction using a three-dimensional (3D) titanium-printed prosthesis. Sternal metastases are a common and devastating complication of advanced breast cancer. If surgical resection is feasible, it presents a complex reconstructive challenge to restore normal and functional anatomy. Herein, we report the first Australian use of a 3D titanium and porous polyethylene printed, custom-made sternal prosthesis in the reconstruction postoperative resection of the sternum for metastatic breast cancer.

An unusual osteoma in the mandibular condyle and the successful replacement of the temporomandibular joint with a custom-made prosthesis: a case report

BackgroundAn osteoma is a benign tumor of bone with unknown etiology and is considered rare, mostly restricted to the craniofacial skeleton.Case presentationThis case report describes an uncommon condylar osteoma in a 67 years old white female patient with laterognathism to the left side, limited mouth opening, aesthetic change and pain associated with the right temporomandibular joint (TMJ). The histopathological examination confirmed osteoma. The lesion was surgically excised and immediate reconstruction was carried out using a custom-made total TMJ prosthesis. The patient has been in follow-up for 2 years, with no symptoms.ConclusionsUnilateral total TMJ prosthesis can be considered to replacement of TMJ after osteoma excision with resection of the condyle.

Alloplastic reconstruction of the temporomandibular joint.

Temporomandibular joint reconstruction (TMJR) is often necessary for patients with severe and/or refractory TMJ disease who have failed conservative treatment. TMJR aids to improve masticatory function and is associated with improved quality of life outcomes. Currently, alloplastic reconstruction is considered as the treatment of choice in most severe TMJ disorders due to its many advantages inclusive but not limited to early mobilization, stable longterm results, and significant improvement in jaw function. Broadly speaking, two types of TMJR prostheses are available for reconstruction: 1) stock, and, 2) custommade prostheses. The purpose of this article is to provide the reader with a brief overview of the basic principles and fundamentals of TMJR while referencing pertinent existing literature.

What Kind of Procedure Should be Indicated for the Comminuted Talar Fracture as Initial Treatment?

Category: Trauma Introduction/Purpose: Open reduction is most difficult to perform in comminuted talar fractures, because it necessitates osteotomy of the lateral or medial malleolus. Furthermore, the incidence of aseptic talar necrosis after a comminuted fracture is extremely high. Fifty-seven tali in 55 patients with aseptic necrosis of the talus underwent replacement with an artificial ceramic whole talus from 2005 to 2015, and we obtained excellent and good results. Based on the results, we performed replacement with an artificial ceramic talus, as the initial treatment, for 6 patients with comminuted talar fractures with bony destruction or defects. Methods: From 2009 to 2016, six feet in 6 patients with comminuted talar fractures were replaced with ceramic whole-talus prostheses as the initial treatment. Of them, 5 were male and one was female, with a mean age of 40.3 years (range, 19–59 years). The causes of the fractures were fall from a high place in 2 patients and traffic accident in 4. The ceramic prosthesis was made based on the computed tomographic scan of the normal opposite talus. The production of the custom-made prosthesis required a period of 5 weeks. In 3 patients, the capacity of the original talus was acquired by external fixation before replacement. Plaster cast immobilization was retained for 2 weeks each of non-weight bearing and weight-bearing. Preoperative and postoperative assessments were performed in accordance with the American Orthopaedic Foot and Ankle Society ankle/hindfoot score system. Results: Follow-up was conducted for 12 to 84 months (mean, 53.8 months). The postoperative AOFAS score was 68-100 (mean, 81.8). The result of the replacement with ceramic whole-talus prosthesis was excellent in 4, good in one, and fair in one. Three patients had resumed participation in sports activities (golf, aerobics, and jogging). However, 2 patients with open fracture and bony defects had limitation of the range of motion of the ankle. The patient with a fair result is still undergoing therapy for femoral and tibial fractures. Conclusion: A ceramic whole-talus prosthesis was used to replace 6 comminuted talar fractures as the initial treatment. The results using these prostheses were excellent, and good except one patient with open fracture and bony defects. Replacement with a ceramic whole-talus prosthesis should be indicated for comminuted fractures with bony destruction or defects.

Development of finite element model for customized prostheses design for patient with pelvic bone tumor.

The aim of this study was to design a hemi-pelvic prosthesis for a patient affected by pelvic sarcoma. To investigate the biomechanical functionality of the pelvis reconstructed with designed custom-made prosthesis, a patient-specific finite element model of whole pelvis with primary ligaments inclusive was constructed based on the computed tomography images of the patient. Then, a finite element analysis was performed to calculate and compare the stress distribution between the normal and implanted pelvis models when undergoing three different static conditions-both-leg standing, single-leg standing for the healthy and the affected one. No significant differences were observed in the stresses between the normal and reconstructed pelvis for both-leg standing, but 20%-40% larger stresses were predicted for the peak stress of the single-leg standing (affected side). Moreover, two- to threefold of peak stresses were predicted within the prostheses compared to that of the normal pelvis especially for single-leg standing case, however, still below the allowable fatigue limitation. The study on the load transmission functionality of prosthesis indicated that it is crucial to carry out finite element analysis for functional evaluation of the designed customized prostheses before three-dimensional printing manufacturing, allowing better understanding of the possible peak stresses within the bone as well as the implants for safety precaution. The finite element model can be equally applicable to other bone tumor model for biomechanical studying.

Management of dentofacial deformities and facial asymmetry with orthognathic surgery concomitant alloplastic temporomandibular joint replacement whit stock prosthesis

Temporomandibular joint (TMJ) disorders or pathology and dentofacial deformities (DFD) commonly coexist. The TMJ pathology may be the causative factor of the jaw deformity or develop as a result of the jaw deformity. Total alloplastic replacement is indicated in TMJ ankylosis, congenital deformation or absence of the TMJ, other end-stage TMJ pathologies, etc. Studies have shown that both custom and stock alloplastic TMJ replacements resulted in statistically significant improvement in pain level, jaw function, and incisal opening. The TMJ stock prosthesis has the advantage of having a more flexible adjustment and lower cost compared to custom made prosthesis, also has immediate placement availability. Objective: The aim of this study is to describe stock alloplastic TMJ total replacement with orthognathic surgery in patients with DFD and concomitant facial asymmetry. Methods: Two patients presenting with congenital and acquired disease DFD and facial asymmetry underwent orthognathic surgery with TMJ alloplastic replacement with stock prosthesis. All patients were planned by traditional model surgery. Conclusions: The TMJ is the basis of the mandibular position, the function, occlusion and facial balance. Several authors have described the performance of orthognathic surgery in conjunction with TMJ alloplastic replacement with custom-made prosthesis, however, there is little literature on performing orthognathic surgery concomitant with stock prosthetic.

Lower limb amputations and rehabilitation

BACKGROUND We wished to study the therapy for lower limb amputees at Sørlandet Hospital Kristiansand after restructuring of activities in 2004.MATERIAL AND METHOD All lower limb amputees hospitalised in the Department of Physical Medicine and Rehabilitation between March 2012 and July 2015 were followed up prospectively.RESULTS A total of 50 patients with 54 amputations were followed up for at least three months. Altogether 31 transtibial amputations, 22 transfemoral amputations and one knee disarticulation were performed. The median age of the patients was 66 years, 36 of whom were men, median Charlson comorbidity index was 1.5, 14 smoked, 8 were substance abusers, 9 were able to walk at least 2 km preoperatively, 44 of the amputations were performed with myodesis, and 41 patients were transferred directly to the Department of Physical Medicine and Rehabilitation. At the three-month check-up, 48 patients used their custom-made prostheses, average walk-test time was 21 seconds, and 45 lived in their own home. At the one-year check-up, 32 of 35 patients who attended used prostheses, and average walk-test time was 18 seconds. Use of painkillers declined during the period. Advanced age, transfemoral amputation and substance abuse were associated with longer walk-test time at the three-month check-up.INTERPRETATION Most patients achieved a good level of function, and the therapy appears to be functioning satisfactorily.

The Benefit of 3D Printing in Medical Field: Example Frontal Defect Reconstruction

This study describes a methodology to design a custom-made cranial prosthesis for a patient who suffered injuries from road traffic accident. Computer based cranial defect reconstruction techniques is developed. The design approach was based on the 3D reconstruction of the skull of the patient, obtained by a CT scan. Then a reverse engineering (RE) method is used to reconstruct the defect prosthesis computer-aided design (CAD) model. Once the prosthesis CAD design was completed, the 3D models the skull and the prosthesis were transported into Rapid Prototyping (RP) machine to fabricate the physical model. Finally, the RP model is directly used to produce the biomaterial calcium phosphate cement (CPC) prosthesis. The prosthesis was successfully implanted and a satisfactory result was obtained by using this design method.

FINITE ELEMENT ANALYSIS OF TOTAL KNEE REPLACEMENT WITH VARIOUS MISALIGNMENT ANGLES IN THE SAGITTAL PLANE

Custom-made prosthetic replacement is a common method of limb reconstruction after surgery of bone tumors. A custom-made tumor knee prosthesis was retrieved after fracture of the tibial stem. The fracture of stem was considered to be associated with some misalignment between the axis of femur and that of the femoral stem, which might cause stress concentration within the tibial component and eventually lead to fracture. To verify this hypothesis, finite element analysis was carried out to study the effect of various tilting degree (6[Formula: see text] forward, 0[Formula: see text] and 6[Formula: see text] backward) of the stem in the sagittal plane on the stress distribution within the tibial component. The calculated maximum Von Mises stress in the tibial component was 225.8, 362.8 and 511.3[Formula: see text]MPa when the femoral component was tilted for 6[Formula: see text] forward, [Formula: see text] and [Formula: see text] backward, respectively. The results demonstrated that the misalignment of femoral components in the sagittal plane has marked effect on the stress distribution of the tibial component.

Negative pressure wound therapy in the management of mine blast injuries of lower limbs: Lessons learnt at a tertiary care center

BackgroundMine blast injuries of foot are devastating injuries that result in composite tissue loss or amputations. Negative pressure wound therapy has helped in the management of such combat-related wounds. The aim of this study was to report experiences gained in managing such injuries at a tertiary care center. Methods17 combatants who sustained mine blast injuries were included in this study. Severity of foot injury was assessed as per Foot and Ankle Severity Score. After wound debridement, negative pressure wound therapy was started and foot defect was appropriately reconstructed. Following wound healing, the foot was assessed for Foot and Ankle Severity Score in terms of impairment. The patients were then suitably rehabilitated by shoe modifications, orthosis, or custom-made prosthesis. ResultsMean age of soldiers who sustained mine blast injuries was 30.2 years. The mean Foot and Ankle Severity Score was 3.76. Temporary wound closure was achieved using negative pressure wound therapy and it prevented local and systemic infection. The defect could be reconstructed appropriately using split skin graft, regional fasciocutaneous flap, or microvascular free flap. Mean time to definitive reconstructive procedure was 16.5 days. Mean Foot and Ankle Severity Score in terms of impairment was 4.11. All soldiers could be rehabilitated and were returned to their respective units and were able to perform sedentary duties assigned to them. ConclusionThe negative pressure wound therapy was helpful in preventing proximal amputations due to mine blast injury and was helpful in satisfactory reconstruction of foot defects.

LUMiC\xae Endoprosthetic Reconstruction After Periacetabular Tumor Resection: Short-term Results

LUMiC\xae Endoprosthetic Reconstruction After Periacetabular Tumor Resection: Short-term Results