The Evolution of Custom Subperiosteal Implants for Treatment of Partial or Complete Edentulism in Patients with Severe Alveolar Ridge Atrophy.

Dental implants have always played an important role in dentistry and have been used to replace missing teeth since around 600 AD. They can be classified into three groups: endosteal, subperiosteal, and transosteal. Over time, different materials have been used to manufacture dental implants and these, in turn, can be divided into three groups: metals, ceramics, and polymers. Today, the most commonly used treatment for edentulism is the use of endosteal implants. However, such an approach cannot be used in patients with severe alveolar ridge atrophy and, in such cases, custom subperiosteal implants are an alternative. This review article focuses on historical developments and improvements that have been made over recent years in treatment options for patients suffering from edentulism and significant resorption of the alveolar ridge. These treatment options involve the utilization of custom subperiosteal implants. This paper looks at the historical evolution of these implants, the significance of diagnostic imaging, and the application of the contemporary methods of production, such as CAD-CAM and additive manufacturing. The research emphasizes the importance of accuracy and personalization provided by these emerging technologies that have rendered subperiosteal implants a more feasible and less intrusive alternative for patients suffering from significant bone loss.

Clinical performance of additively manufactured subperiosteal implants: a systematic review.

PURPOSE: The aim of this study was to assess implant survival and complications rate of modern subperiosteal implants (CAD designed and additively manufactured). METHODS: A systematic review was conducted using three electronic databases; Medline (Pubmed), Cochrane library, and SCOPUS, following the PRISMA statement recommendations to answer the PICO question: "In patients with bone atrophy (P), do additively manufactured subperiosteal implants (I), compared to subperiosteal implants manufactured following traditional approaches (c), present satisfactory implant survival and complication rates (O)? The study was pre-registered in PROSPERO (CRD42023424211). Included articles quality was assessed using the "NIH quality assessment tools". RESULTS: Thirteen articles were finally selected (5 cohort studies and 8 case series), including 227 patients (121 female / 106 male; weighted mean age 62.4 years) and 227 implants. After a weighted mean follow-up time of 21.4 months, 97.8% of implants were in function (5 failures reported), 58 implants (25.6%) presented partial exposure, 12 patients (5.3%) suffered soft tissue or persistent infection. Fracture of the interim prosthesis was reported in 8 of the155 patients (5.2%) in which the use of a provisional prosthesis was reported. A great heterogeneity was found in terms of study design and methodological aspects. For this reason, a quantitative analysis followed by meta-analysis was not possible. CONCLUSIONS: Within the limitations of this study, modern additively manufactured subperiosteal implants presented a good survival in the short-time, but a noticeable number of soft-tissue related complications were reported. Further studies are needed to assess the clinical behavior in the medium- and long-term.

Custom-made total ankle arthroplasty with patient-specific instrumentation for severe bone loss conditions: a case series.

PURPOSE: Management of bone loss around the ankle is a challenging condition. This retrospective study describes the design process, the surgical technique, and the preliminary results of custom-made total ankle arthroplasties (TAA) with patient-specific instrumentation (PSI) for different severe bone loss conditions. METHODS: Consecutive patients that underwent custom-made TAA for severe bone loss conditions were included. The primary outcome was to describe the implant design in relation to the bone defect. Moreover, pre-operative and final follow-up clinical scores were compared. RESULTS: Seven patients were included. Post-operative radiographs showed good correspondence between the pre-operative planning and the prosthesis alignment in all patients. Improvement in clinical scores was observed in all patients at the final follow-up. One patient developed a deep infection. CONCLUSION: Short-term results reported herein are encouraging suggesting that custom-made TAA implants with PSI may represent an effective solution for ankle bone loss conditions.

The Role of 3D-Printed Patient-Specific Instrumentation in Total Knee Arthroplasty: A Literature Review.

Total knee arthroplasty (TKA) is currently one of the most common orthopedic surgeries due to the ever-increasing average life expectancy. The constant need for effective and accurate techniques was contributed to the development of three-dimensional (3D) printing in that field, especially for patient-specific instrumentation (PSI) and custom-made implants fabrication. PSI may offer numerous benefits, such as resection accuracy, mechanical axis alignment, cost-effectiveness, and time economy. Nonetheless, the results of existing studies are controversial. For this purpose, a review article of the published articles was conducted to summarize the role of 3D-printed PSI in TKA.

Patient Specific Instruments and Patient Individual Implants-A Narrative Review.

Joint arthroplasties are one of the most frequently performed standard operations worldwide. Patient individual instruments and patient individual implants represent an innovation that must prove its usefulness in further studies. However, promising results are emerging. Those implants seem to be a benefit especially in revision situations. Most experience is available in the field of knee and hip arthroplasty. Patient-specific instruments for the shoulder and upper ankle are much less common. Patient individual implants combine individual cutting blocks and implants, while patient individual instruments solely use individual cutting blocks in combination with off-the-shelf implants. This review summarizes the current data regarding the implantation of individual implants and the use of individual instruments.

The Possibilities of Personalized 3D Printed Implants-A Case Series Study.

Background and Objectives: Following the most recent software and 3D printing developments, the use of personalized 3D printed orthopedic implants for treatment of complicated surgical cases has gained more popularity. Today, orthopedic problems that cannot be solved with standard implants may be effectively addressed using personalized prostheses. The aim of this study is to present the designing, modeling and production stages of four different personalized 3D printed prostheses and their application in clinical cases of patients who underwent treatment in various anatomical locations with a precisely specified indication for implantation. Materials and Methods: Based on computed tomography scanning, personalized 3D printed prostheses were designed, produced and used in four patients within a period of three to five days after injury or admission. Results: Early term follow-ups demonstrated good to excellent results. Conclusions: Personalized 3D printed prostheses offer an opportunity for a treatment of choice and provide good anatomical and functional results, shortened surgical time, less complications, and high satisfaction in patients with appropriate indications. The method should be considered primarily for patients with large bone defects, or such indicated for resection. Personalized 3D printed prostheses have the potential to become more common and beneficial in the future.

Current and Emerging Approaches for Spine Tumor Treatment.

Spine tumors represent a significant social and medical problem, affecting the quality of life of thousands of patients and imposing a burden on healthcare systems worldwide. Encompassing a wide range of diseases, spine tumors require prompt multidisciplinary treatment strategies, being mainly approached through chemotherapy, radiotherapy, and surgical interventions, either alone or in various combinations. However, these conventional tactics exhibit a series of drawbacks (e.g., multidrug resistance, tumor recurrence, systemic adverse effects, invasiveness, formation of large bone defects) which limit their application and efficacy. Therefore, recent research focused on finding better treatment alternatives by utilizing modern technologies to overcome the challenges associated with conventional treatments. In this context, the present paper aims to describe the types of spine tumors and the most common current treatment alternatives, further detailing the recent developments in anticancer nanoformulations, personalized implants, and enhanced surgical techniques.

[Congenital thoracic deformities and 3D custom-made implants. New classification based on a series of 789 treated cases]. / Malformations thoraciques congénitales et implants sur mesure 3D. Nouvelle classification basée sur une série de 789 cas traités.

The authors present a new study on 789 cases of congenital thoracic malformations including 638 pectus excavatum and 151 Poland syndromes, according to a new classification which completes Chin's one. All these malformations were treated with silicone elastomer implants. The contribution of computer-aided design and manufacturing (CAD/CAM) since 2008 is essential. The one-stage surgical protocol is precisely described. The results are impressive, permanent, for life, and complications are rare. The authors evoke a common vascular etiopathogenesis theory at the embryonic stage and question the heavy techniques of invasive remodeling that are most often unjustified.

[Breasts and congenital chest-wall deformities: Surgical strategy with 3D implants]. / Le sein et les malformations thoraciques : stratégie chirurgicale et implants.

Computer-aided design and manufacturing of custom-made elastomer implants leads from a CT scan to fill in with precision, a congenital chest wall congenital deformity, both bone (pectus excavatum) and muscle (Poland Syndrome), resulting in a natural repositioning of the breasts. We report our 25 years' experience in 301 women (234 Pectus+64 Poland). Parietal correction must always be done in first intention. It is common to have to carry out a second stage in women with an additional mammaplasty especially in the presence of insufficient glandular volume or a fairly frequently associated tuberous breast.

[Place of 3D custom-made implants after failure of modeling steno-chondro-plasties]. / Place des implants sur mesure 3D après échec des sterno-chondro-plasties modelantes.

Most common congenital malformation of the thorax, Pectus Excavatum affects about one in 500 people. Several surgical or medical techniques have been proposed. Some are followed by complications or insufficient results even though their constant functional value is highly controversial. Secondary surgery with a deep customized 3D elastomer implant, may be an elegant effective and safe solution compared to others; it allows a good aesthetic result expected by patients in the absence of any respiratory or cardio-vascular functional context.

Custom made cutting guides and osteosynthesis plates versus CAD/CAM occlusal splints in positioning and fixation of the maxilla in orthognathic surgery: A prospective randomized study.

The aim of this study is to compare the accuracy of maxilla positioning in orthognathic surgery with the use of custom-made devices (cutting guides and patient-fitted osteosynthesis plates) comparing to CAD/CAM splints. A prospective randomized study was performed. Patients with dentofacial deformities undergoing orthognathic surgery were compared, using customized guides (experimental group) vs. CAD/CAM surgical splints (control group) for the repositioning of the upper maxilla. Preoperative and postoperative CT scans were used to compare positioning and fixation of the maxilla in the three planes of space. A total of 30 patients were included in the study (15 patients in each study group). The mean error obtained with customized guides was 0.8 mm (range 0.1-1.9) in the anterior-posterior axis, 0.4 mm (range 0-1.4) in the vertical axis and 0.2 mm (range 0-1.1) in the horizontal axis. There were statistically significant differences in the anterior-posterior and vertical axes in favour of the customized implants, whereas there were no differences in the horizontal plane. Furthermore, there was a mean reduction of the operative time of 36.5 min in the experimental group. Within the limitations of the study it seems that patient specific surgical guides should be preferred when accuracy of repositioning of the maxilla and saving operative time are the priority.

Case Report: Simultaneous Resection of Bone Tumor and CAD/CAM Titanium Cranioplasty in Fronto-Orbital Region.

Background: Simultaneous resection of bone tumors in the fronto-naso-orbital region is a great challenge due to the need for adequate reconstruction of the facial skeleton. Pre-operative virtual planning of resection margins and the simultaneous fabrication of the cranioplasty using computer-aided design/computer-aided manufacturing (CAD/CAM) technology could allow combining the tumor resection and cosmetic restoration steps into a single procedure. Methods: We present five consecutive cases of patients with bone tumors of the fronto-naso-orbital region. The indications for surgery included: (1) the presence of a major cosmetic defect; (2) progressive tumor growth. The histological examination revealed vascular malformation, hemangioma, and fibrous dysplasia in two cases. Tumor resection was performed with the help of a drilling template in form of a tumor. The computer-designed cranioplasty formed based on the non-involved side of the skull of the patient was manufactured. In one patient, the reconstruction was performed using two separate implants. Results: The position of the implant fits in with pre-operative planning in two cases; in those cases, the additional trimming of the implant or bone defect was required. Good cosmetic outcomes were noted in all patients, and no complications occurred. No repeat surgery was necessary. The template has proved to have high application potential. Conclusion: Simultaneous resection and CAD/CAM cranioplasty in the case of bone tumors in the fronto-orbital region is a promising technique with the aim of minimizing operation time and achieving a good esthetic outcome.

"Single-step" resection and cranio-orbital reconstruction for spheno-orbital metastasis with custom made implant. A case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Brain metastasis involving the skull base is a rare complication of malignant tumors. Besides radiotherapy, surgical treatment is a therapeutical option even though it may apply complex technical procedures that may delay complementary therapies. However, in recent days, the innovation of custom-made implants allows treating selected patients with fewer complications and better results. CASE PRESENTATION: We describe a single case of a complex fronto-orbital skull base metastasis requiring skull bone reconstruction that we treated with a single-step surgery and custom-made implant. Our procedure consists of two steps: in the first one, we perform a "virtual" craniotomy on a 3D phantom model previously built on a high-resolution bone CT scan. In the second step, the actual surgical procedure, the patient undergoes the resection and reconstruction of the cranial defect with an implant of PMMA custom-made cranioplasty. A three-month clinical and radiological follow-up is reported, which documented the extent of resection and good aesthetic results. CLINICAL DISCUSSION: In our case, we performed a skull reconstruction of cranio-orbital region with macroscopic gross-total resection of the tumor. Complementary radiotherapy was obtained after one month. Three-month follow-up showed good esthetic results and progression-free disease. A recent review of the literature is provided to discuss different reconstruction techniques. CONCLUSION: "Single-Step" resection and custom-made reconstruction is a relatively new technique that could be helpful not only for benign tumors, which remains its main application but also in selected cases of malignant tumors when immediate reconstruction and faster complementary treatments are needed.

[New technologies (robotics, "custom-made") for unicondylar knee arthroplasty-contra]. / Neue Technologien (Robotik, "custom made") in der unikondylären Knieendoprothetik ­ Contra.

BACKGROUND: Numerous long-term results for both medial and lateral unicondylar knee arthroplasty (UKA) demonstrate that UKA is a reliable and successful treatment for isolated anteromedial or lateral osteoarthritis of the knee when the correct indications are used. The relationship between operation volume and implant performance has clearly been established from recent studies and registry data. The use of novel technologies allows for an improvement in the accuracy of implant positioning with fewer outliers. However, evidence-based target zones for the positioning of available implants have not been sufficiently established. INDIVIDUAL ENDOPROSTHETICS: Current data does not support the routine use of patient-specific instruments or custom-made implants. ROBOTICS: Robot-assisted procedures must be interpreted as a very promising approach for the future. So far, there is insufficient evidence that robotically assisted surgical techniques improve implant performance or lead to better functional results from the patient's point of view.

Clinical study of outcomes after revision surgery using porous titanium custom-made implants for severe acetabular septic bone defects.

PURPOSE: Acetabular bone loss is a challenging problem in revision total hip arthroplasty (rTHA). Severe bone loss is not uncommon especially in periprosthetic joint infection. Surgical options, including revision shells, rings, and cages-with or without bone allograft-are affected by high complication rates and unsatisfactory clinical results. We report our mid-term results of non-flanged, custom-made acetabular components in staged rTHA. METHODS: We retrospectively reviewed all patients undergoing two-stage revision with acetabular custom-made implants between 2014 and 2016 at a single institution. Harris Hip Scores, Oxford Hip Scores, and Visual Analogue Scales for pain were obtained, and radiographical follow-up was performed. Complications were reported and analysed. RESULTS: We included 19 patients (19 hips) with an average follow-up of 42.3 ± 11.8 months. At the time of re-implantation, significant acetabular bone loss according to Paprosky classification (IIC, IIIA-B, and pelvic discontinuity) was detected in our patients. Clinical outcomes showed statistically significant improvement from pre-operative visit to last follow-up (p < 0.01). All custom-made implants had radiological osseointegration, and we did not find any implant complications, such as loosening or malposition. No mismatch between pre-operative planning and intra-operative findings was observed. To date, we report one septic failure managed with second staged revision, and one re-operation for recurrent THA dislocation. CONCLUSIONS: Custom-made acetabular implants showed excellent clinical and radiographic mid-term outcomes with a low rate of related complications, providing implant stability on residual host bone, restoring hip biomechanics, and allowing biological osseointegration. Further long-term studies are needed to confirm preliminary results.

The Role of Custom-made Subperiosteal Implants for Rehabilitation of Atrophic Jaws - A Case Report.

Rehabilitation of atrophic jaws with conventional endosseous implant-supported overdentures and immediate loading protocols still presents a challenge nowadays. Custom-made implants with immediate loading overdenture are emerging as a solution for atrophic jaws rehabilitation. The authors describe the case of a 44-year-old male with a history of congenital dental agenesis. A previous oral rehabilitation with an all-on-6 type, implant-fixed mandibular overdenture, had failed due to peri-implantitis. The patient was successfully treated with bimaxillary custom-made subperiosteal implants with an innovative design, combining subperiosteal and endosseous support. The authors consider custom-made subperiosteal implants, in selected patients, present several advantages over classic bone-grafting plus endosseous implant-placement techniques such as (1) possibility of a single-stage procedure with immediate loading in atrophic jaws; (2) possible primary option to approach atrophic jaws as a simpler and less time-consuming technique; and (3) a valid rescue option for failed endosseous implants. More long-term studies with large samples of patients will be necessary to confirm previous assumptions.

Use of 3-Dimensional Printing Technology in Complex Spine Surgeries.

BACKGROUND: Medical implications of 3-dimensional (3D) printing technology have evolved and are increasingly used. Surgical spine oncology involves at times complex resection using various surgical approaches and unique spinal reconstruction. As high general complication rates, including hardware failure, are reported, careful preoperative planning and optimized fixation techniques should be performed. 3D printing technology allows the improvement of preoperative planning, practice and exploration of various surgical approaches, and designing customized surgical tools and patient specific implants. OBJECTIVE: To investigate the use of 3D printing technology in complex spine surgeries. METHODS: Between 2015 and 2018, all complex spine oncological cases were evaluated and assessed for the possible benefit of use of 3D printing technology. Following high-quality imaging, a computerized integrated 3D model was created. Based on the planned procedure considering the various surgical steps, a customized 3D model was planned and printed, and in select cases a 3D custom-made implant was designed and printed in various sizes with matching trials. RESULTS: A total of 7 cases were selected for the use of a 3D printing technology. For all, a custom-made model was created. In 3 of these cases, a customized 3D-printed implant was used. Special customized intraoperative instruments were made for 2 cases, and a simulated surgical approach was performed in 5 cases. In 2 cases, pre-bent rods were made based on the model created and were used in surgery later on. CONCLUSIONS: For complex spine oncology cases, the use of 3D printing allowed better preoperative planning, simplified the operative procedure, and enabled improved reconstruction.

The design, production and clinical application of 3D patient-specific implants with drilling guides for acetabular surgery.

An innovative procedure for the development of 3D patient-specific implants with drilling guides for acetabular fracture surgery is presented. By using CT data and 3D surgical planning software, a virtual model of the fractured pelvis was created. During this process the fracture was virtually reduced. Based on the reduced fracture model, patient-specific titanium plates including polyamide drilling guides were designed, 3D printed and milled for intra-operative use. One of the advantages of this procedure is that the personalised plates could be tailored to both the shape of the pelvis and the type of fracture. The optimal screw directions and sizes were predetermined in the 3D model. The virtual plan was translated towards the surgical procedure by using the surgical guides and patient-specific osteosynthesis. Besides the description of the newly developed multi-disciplinary workflow, a clinical case example is presented to demonstrate that this technique is feasible and promising for the operative treatment of complex acetabular fractures.