Comparison of the MIPS technique versus linear incision with tissue preservation in osseointegrated implants in the Ponto model®.

BACKGROUND AND OBJECTIVES: The surgery of osseointegrated implants has undergone different modifications over the years with the aim of achieving better results and facilitating the surgical technique. Today the most commonly used technique is the linear incision with tissue preservation and placement of the abutment and implant. The long-term success of this technique has served as the basis for the development of the so-called minimally invasive surgical approach (MIPS). This study compares the short-, medium- and long-term results between the classic linear incision technique and the MIPS technique. MATERIAL AND METHODS: A prospective study was conducted on patients who had an osseointegrated implant placed between February 2016 and February 2020. A total of 59 surgeries were performed, 32 surgeries according to the linear incision technique with tissue preservation and 27 with MIPS technique. Outcomes were evaluated at one week, one month and one year. RESULTS: Statistically significant differences were achieved between the 2 groups at one week after surgery. Eighty per cent of the MIPS patients had Holgers grades 0-1 compared to 35% of the linear technique patients (p = 0.001). No statistically significant differences were observed at one month (p = 0.457) and one year (p = 0.228). One case with grade 4 was recorded which resulted in implant extrusion one month after surgery with the MIPS technique. A new osseointegrated implant was placed 2 months after the fall using the same MIPS technique with good results. We were also able to verify that the duration of surgery was much shorter with the MIPS technique and better tolerated in terms of postoperative discomfort by the patient. CONCLUSIONS: In our experience, the MIPS technique is the technique of choice for surgery of osseointegrated Ponto model implants as it is simpler, faster and presents fewer problems in the immediate postoperative period, with similar long-term postoperative results.

Mechanical load applied by Intraosseous Transcutaneous Amputation Prosthesis (ITAP) during walking on level and sloped treadmill: A case study.

This proof of concept study presents a method to collect and analyse kinetic data from one participant with a transfemoral amputation fitted with a percutaneous osseointegrated implant walking on a level and sloped treadmill. We describe the construction of and results from a bespoke wireless six axis load cell built into one participant's prosthetic assembly. The load cell does not clinically compromise the participant in any way and is an initial milestone in the development of a light-weight wireless load cell for use with percutaneous osseointegrated implants. In this case, it is the first time that kinetic data from a participant fitted with an Intraosseous Transcutaneous Amputation Prosthesis has been published. We propose that the data can be used to model the load transfer to the host bone, with several clinically significant applications. The raw dynamic data are made available and quasi-static load cases for each functional phase of gait are presented. Peak forces obtained in the medio-lateral (X), cranio-caudal (Y) and antero-posterior (Z) axes over level ground respectively were -243.8 N (0.24 BW), 1321.5 N (1.31 BW) and -421.8 N (0.42 BW); uphill were -141.0 N (0.14 BW), 1604.2 N (1.59 BW), -498.1 N (0.49 BW); downhill were -206.0 N (0.20 BW), 1103.9 N (1.09 BW), -547.2 N (0.54 BW). The kinetics broadly followed able bodied gait patterns with some gait strategies consistent in participants with other implant designs or prosthetic socket connections, for example offloading the artificial limb downhill.

Patient-matched osseointegrated prostheses for thumb amputees: a cadaver and feasibility study.

Thumb amputations affect 50% of hand functionality. Common solutions consist of microsurgical treatments or silicone vacuum prosthesis. Not all patients are eligible for microsurgical treatment and the use of vacuum prosthesis is often discouraged because of their instability. On the contrary, osseointegrated prosthesis provide stable retention and osseoperception. This cadaveric study evaluated the process of a patient-matched osseointegrated prosthesis for the treatment of thumb amputees. Computed tomography (CT) medical images reconstruction provided information on metacarpal stump, used as input for the parametric screw design. Preoperative planning guided the surgeons in the surgery: postoperative placement confirmed the accuracy of the preoperative planning. Surgeons were directly involved in the implant design to meet their requirements and patient needs. Implants were inserted into cadaveric specimens in one-stage surgery. A similar process can be adopted and exploited for the treatment of different levels of thumb amputations and long finger amputations.

Magnetic Resonancy Imaging Safety in Active Osseointegrated (Osia®) and Cochlear Implants: New Technology Creating Confusion.

OBJECTIVE: There is increased confusion regarding MRI-compatible CIs and BAHAs. This report describes two cases when patients underwent MRIs with non-MRI compatible devices. RESULTS: One patient with bilateral Cochlear Osias experienced dislocation of both internal magnets after 1.5 Tesla MRI. Both magnets were outside the silastic sheath, with the left magnet flipped. A second patient with a legacy CI experienced similar internal magnet dislocation and inversion after 3 Tesla MRI. CONCLUSIONS: This study describes internal magnet dislocation/inversion with the Cochlear Osia and a legacy CI after MRI. Our findings suggest the need for improved patient education and simplified radiology guidelines. Laryngoscope, 134:393-396, 2024.

Semi-automated generation of bone loss defects around dental implants and its application in finite element analysis.

This study aimed to develop an algorithm for modelling bone loss defects in a given mandibular geometry, with a user-defined depth, width, place, and defect type. The algorithm was implemented using Grasshopper and models with different bone loss types and depths around a dental implant were built. The models were used in a finite element analysis (FEA) to predict the stresses in peri-implant bone. The FEA showed that the stresses in peri-implant bone depend primarily on the depth of bone loss, whereas the type of bone loss showed no major influence.

Comparison of conventional socket attachment and bone-anchored prosthesis for persons living with transfemoral amputation - mobility and quality of life.

BACKGROUND: For patients with transfemoral amputation experiencing issues with their sockets, bone-anchored prosthesis systems are an alternative and sometimes the only way to be mobile and independent. The present cross-sectional study aimed to investigate the gait performance and quality of life of a group of patients treated with bone-anchored systems compared to those of participants treated with a conventional socket-suspended prosthesis. METHODS: A total of 17 participants with a socket-suspended and 20 with a bone-anchored prosthesis were included. Gait patterns were examined for symmetry, and performance was assessed using the six-minute walk test and the timed "Up & Go" test. Magnetic resonance imaging was performed to detect signs of osteoarthritis in both hips. Mobility in everyday life and quality of life were assessed using questionnaires. FINDINGS: There were no differences between the groups regarding the quality of life, daily mobility, and gait performance. The step width was significantly higher for the patients using socket-suspended prosthesis. The socket-suspended group showed a significant asymmetry regarding the step length. In the socket-suspended group, the prosthetic leg showed significantly higher cartilage abrasion than the contralateral leg did. INTERPRETATION: Large differences in the measured outcomes in both groups illustrate the very different capabilities of the individual participants, which is apparently not primarily determined by the type of treatment. For patients who are satisfied with the socket treatment and perform well, bone-anchored prosthesis systems may not necessarily improve their functional capabilities and perceived quality of life.

Patient-Specific Guides for Accurate and Precise Positioning of Osseointegrated Implants in Transfemoral Amputations: A Proof-of-Concept In Vitro Study.

Background and Objectives: The treatment of transfemoral amputees using osseointegrated implants for prosthetic anchorage requires accurate implant positioning when using threaded bone-anchoring implants due to the curvature of the femur and the risk of cortical penetration in misaligned implants. This study investigated the accuracy and precision in implant positioning using additively manufactured case-specific positioning guides. Materials and Methods: The geometry and density distribution of twenty anatomic specimens of human femora were assessed in quantitative computed tomography (QCT) scanning. The imaging series were used to create digital 3D specimen models, preoperatively plan the optimal implant position and manufacture specimen-specific positioning guides. Following the surgical bone preparation and insertion of the fixture (threaded bone-anchoring element) (OPRA; Integrum AB, Mölndal, Sweden), a second QCT imaging series and 3D model design were conducted to assess the operatively achieved implant position. The 3D models were registered and the deviations of the intraoperatively achieved implant position from the preoperatively planned implant position were analyzed as follows. The achieved, compared to the planned implant position, was presented as resulting mean hip abduction or adduction (A/A) and extension or flexion (E/F) and mean implant axis offset in medial or lateral (M/L) and anterior or posterior (A/P) direction measured at the most distal implant axis point. Results: The achieved implant position deviated from the preoperative plan by 0.33 ± 0.33° (A/A) and 0.68 ± 0.66° (E/F) and 0.62 ± 0.55 mm (M/L) and 0.68 ± 0.56 mm (A/P), respectively. Conclusions: Using case-specific guides, it was feasible to achieve not only accurate but also precise positioning of the implants compared to the preoperative plan. Thus, their design and application in the clinical routine should be considered, especially in absence of viable alternatives.

A Potential Interaction Between Bisphosphonates and Osseointegration of Bone-Anchored Hearing Aid Implants Leading to Late Device Extrusion.

Bisphosphonate therapy is commonly used to treat patients suffering from osteoporosis due to its clinical effectiveness and its generally benign safety profile; however, osteonecrosis of the jaw is a rare side effect that can occur in some patients. A far less elucidated area of concern is the effect of these medications on osseointegrated implants, which require adequate bone formation to ensure long-term viability of the implant. To date, there are no reports in the otolaryngology literature examining the interplay between osteoporosis, bisphosphonate therapy, and osseointegrated bone-anchored hearing aids (BAHA). In this case report, we describe an osteoporotic patient on bisphosphonates experiencing late bilateral failure of her osseointegrated BAHA implants shortly after starting therapy. Certainly, direct causality cannot be determined from this single report, but the temporal relationship described in this case suggests a potential interaction between bisphosphonate use and delayed failure of the osseointegrated hearing devices. Consequently, otolaryngologists who implant osseointegrated hearing devices should consider offering preoperative counseling to patients receiving bisphosphonate therapy.

Integrating skeletal anchorage into fixed and aligner biomechanics.

Routine alignment with fixed appliances and aligners is indeterminate mechanics because equilibrium equations are only applicable to two abutments: teeth, segments, or arches. Orthodontists must depend on compliance and resilience of materials (archwires and aligners) for initial alignment. However, stabilized segments and arches are "large multirooted teeth" that can be moved with determinate mechanics using temporary skeletal anchorage devices. Temporary skeletal anchorage devices have advanced from retromolar implants and inter-radicular miniscrews to extra-alveolar bone screws placed in the basilar bone buccal to the first molars: mandibular buccal shelf and infrazygomatic crest. Extra-alveolar anchorage is determinate mechanics to move teeth, segments, and arches. Retraction and rotation of the lower arch reverses the etiology of Class III open bite malocclusion to correct severe skeletal dysplasia with no extractions or orthognathic surgery.

Transinusal Pathway Removal of an Impacted Third Molar with an Unusual Approach: A Case Report and a Systematic Review of the Literature.

BACKGROUND: The purpose of the present case report was to investigate a very rare ectopic third molar removal by a trans-sinusal approach and report the study findings through a systematic review of the literature on this topic. CASE PRESENTATION: A 38-year-old female patient was visited for pain at the level of the right maxillary region. No relevant medical history was reported. The CBCT tomography assessment revealed an impacted third tooth at the level of the postero-lateral maxilla. REVIEW METHODS: An electronic search was performed through Boolean indicators query on Pubmed/Medline, EMBASE, Cochrane Library databases. The clinical reports were identified and selected in order to perform a descriptive analysis. The surgical approach concerned a trans-sinusal access to the site for the ectopic tooth removal with a lateral antrostomy. No evident inflammatory alteration was associated to the ectopic tooth and a non-relevant post-operative sequelae was reported at the follow up. RESULTS: A total of 34 scientific papers were retrieved from the database search. Only two cases reported a wait-and-see radiographical follow-up approach, while the most common treatment was surgical removal, also for asymptomatic cases. CONCLUSION: The third-molar ectopic tooth into the maxillary sinus is an uncommon occurrence that is beast treated by an in-chair intraoral tran-sinusal approach, with a consistent reduction of the invasivity, a mild morbidity and a successful functional outcome.

Modifications to Implanting the OSIA® 2 Bone Conduction Hearing Implant: How I Do it.

This "How I Do It" report describes modifications made to the OSIA bone conduction hearing implant surgery in order to reduce wound complications. Laryngoscope, 132:1850-1854, 2022.

Osseointegrated Metallic Implants for Finger Amputees: A Review of the Literature.

Digital trauma amputations and digital agenesis strongly affect the functionality and aesthetic appearance of the hand. Autologous reconstruction is the gold standard of treatment. Unfortunately, microsurgical options and transplantation procedures are not possible for patients who present contraindications or refuse to undergo transplantation from the toe (e.g. toe-to-thumb transplantation). To address these issues, osseointegrated finger prostheses are a promising alternative. The functional assessments registered during follow-up confirmed the promising outcomes of osseointegrated prostheses in the treatment of hand finger amputees. This review outlines (a) a detailed analysis of osseointegrated finger metallic components of the implants, (b) the surgical procedures suggested in the literature, and (c) the functional assessments and promising outcomes that demonstrate the potential of these medical osseointegrated devices in the treatment of finger amputees.

Effects of extended high frequency bandwidth in osseointegrated bone conduction device users.

High-frequency hearing above 5000 Hz improves the detection and discrimination of high frequency phonemes. Improved access to high-frequency hearing may be particularly advantageous in unilaterally deafened listeners who experience reduced access to high frequency speech cues on their impaired side and decreased speech perception abilities in competing noise. This study aimed to investigate the effects of extended high-frequency bandwidth on speech perception in unilaterally deafened osseointegrated bone conduction hearing device recipients. To study the effect of extended high-frequency bandwidth, participants underwent aided testing in narrow bandwidth and extended high-frquency bandwidth BCD listening conditions. Aided word and phoneme recognition in quiet was assessed at soft and conversational speech levels with the better ear plugged. Aided thresholds and Ling 6 phoneme sounds were also assessed in quiet with the better ear plugged. Speech perception in noise was assessed at ± 90° and co-located at 0° using the adaptive Hearing in Noise Test. Findings demonstrate a significant improvement in speech perception outcomes when listening with extended high-frequency bandwidth. Extended high-frequency bandwidth significantly improved word and phoneme recognition for soft and average conversational speech. The largest effects were observed for voiceless phonemes. Results suggest use of bone conduction devices with extended high-frequency bandwidth result in improved hearing outcomes when compared with narrow bandwidth bone conduction devices.

Novel Surgical Technique in Active Bone Conduction: Minimally Invasive Approach to Fully Implantable Osseointegrated Implant.

We report our experience using a novel minimally invasive surgical technique for implantation of a fully implantable active bone conduction implant. This was a retrospective review of 16 adults, including 10 women and 6 men. The mean age was 54 years. Hearing loss profiles included 8 with mixed hearing loss, 5 with conductive hearing loss, and 3 with single-sided deafness. Nine patients underwent placement through the standard approach and 7 with the minimally invasive approach. There were no postoperative complications at a mean follow-up of 6.5 months (SD, 4; range, 1.5-12), and all patients received audiologic benefit with objective improvement in sound-field thresholds upon activation. Mean operative time was shorter with the minimally invasive approach (64 vs 41 minutes, P = .01). The fully implantable bone-anchored auditory implant can be effectively placed via a minimally invasive incision, with potential benefits of decreased operative time, low risk for intra- and postoperative complications, and rapid healing.

Culture and characterization of various porcine integumentary-connective tissue-derived mesenchymal stromal cells to facilitate tissue adhesion to percutaneous metal implants.

BACKGROUND: Transdermal osseointegrated prosthesis have relatively high infection rates leading to implant revision or failure. A principle cause for this complication is the absence of a durable impervious biomechanical seal at the interface of the hard structure (implant) and adjacent soft tissues. This study explores the possibility of recapitulating an analogous cellular musculoskeletal-connective tissue interface, which is present at naturally occurring integumentary tissues where a hard structure exits the skin, such as the nail bed, hoof, and tooth. METHODS: Porcine mesenchymal stromal cells (pMSCs) were derived from nine different porcine integumentary and connective tissues: hoof-associated superficial flexor tendon, molar-associated periodontal ligament, Achilles tendon, adipose tissue and skin dermis from the hind limb and abdominal regions, bone marrow and muscle. For all nine pMSCs, the phenotype, multi-lineage differentiation potential and their adhesiveness to clinical grade titanium was characterized. Transcriptomic analysis of 11 common genes encoding cytoskeletal proteins VIM (Vimentin), cell-cell and cell-matrix adhesion genes (Vinculin, Integrin ß1, Integrin ß2, CD9, CD151), and for ECM genes (Collagen-1a1, Collagen-4a1, Fibronectin, Laminin-α5, Contactin-3) in early passaged cells was performed using qRT-PCR. RESULTS: All tissue-derived pMSCs were characterized as mesenchymal origin by adherence to plastic, expression of cell surface markers including CD29, CD44, CD90, and CD105, and lack of hematopoietic (CD11b) and endothelial (CD31) markers. All pMSCs differentiated into osteoblasts, adipocytes and chondrocytes, albeit at varying degrees, under specific culture conditions. Among the eleven adhesion genes evaluated, the cytoskeletal intermediate filament vimentin was found highly expressed in pMSC isolated from all tissues, followed by genes for the extracellular matrix proteins Fibronectin and Collagen-1a1. Expression of Vimentin was the highest in Achilles tendon, while Fibronectin and Col1agen-1a1 were highest in molar and hoof-associated superficial flexor tendon bone marrow, respectively. Achilles tendon ranked the highest in both multilineage differentiation and adhesion assessments to titanium metal. CONCLUSIONS: These findings support further preclinical research of these tissue specific-derived MSCs in vivo in a transdermal osseointegration implant model.

Thermal Effects during Bone Preparation and Insertion of Osseointegrated Transfemoral Implants.

BACKGROUND: The preparation of bone for the insertion of an osseointegrated transfemoral implant and the insertion process are performed at very low speeds in order to avoid thermal damages to bone tissue which may potentially jeopardize implant stability. The aim of this study was to quantify the temperature increase in the femur at different sites and insertion depths, relative to the final implant position during the stepwise implantation procedure. METHODS: The procedure for installation of the osseointegrated implant was performed on 24 femoral specimens. In one specimen of each pair, the surgery was performed at the clinically practiced speed, while the speed was doubled in the contralateral specimen. Six 0.075 mm K fine gauge thermocouples (RS Components, Sorby, UK) were inserted into the specimen at a distance of 0.5 mm from the final implant surface, and six were inserted at a distance of 1.0 mm. RESULTS: Drilling caused a temperature increase of <2.5 °C and was not statistically significantly different for most drill sizes (0.002 < p < 0.845). The mean increase in temperature during thread tapping and implant insertion was <5.0 °C, whereas the speed had an effect on the temperature increase during thread tapping. CONCLUSIONS: Drilling is the most time-consuming part of the surgery. Doubling the clinically practiced speed did not generate more heat during this step, suggesting the speed and thus the time- and cost-effectiveness of the procedure could be increased. The frequent withdrawal of the instruments and removal of the bone chips is beneficial to prevent temperature peaks, especially during thread tapping.

Review of Bone Conduction Hearing Devices.

Bone conduction is an efficient pathway of sound transmission which can be harnessed to provide hearing amplification. Bone conduction hearing devices may be indicated when ear canal pathology precludes the use of a conventional hearing aid, as well as in cases of single-sided deafness. Several different technologies exist which transmit sound via bone conduction. Here, we will review the physiology of bone conduction, the indications for bone conduction amplification, and the specifics of currently available devices.

The use of medical modeling in microvascular free tissue transfer reconstruction with osseointegrated implantation in complex midface defects.

Osseointegrated implants in conjunction with microvascular free tissue transfer reconstruction has been increasingly adopted in our head and neck cancer population. However, the majority of the literature on dental rehabilitation in free flaps have been for mandibular defects. Midface and maxillectomy defects are challenging defects for reconstruction. The utilization of medical modeling technology has allowed for improved efficiency and accuracy of microvascular free tissue transfer reconstruction of these midface defects and opened the possibility of immediate osseointegrated implant placement. Medical modeling in microvascular free tissue transfer reconstruction with immediate dental rehabilitation in complex midface defects will be discussed. A review of the literature as well as our experience in the surgical management of these patients is provided.

Systematic review and pooled analysis of survival rates, success, and outcomes of osseointegrated implants in a variety of composite free flaps.

The aim of this review was to provide an update on survival rates of osseointegrated implants into common composite free flaps used for maxillary and mandibular reconstructions and identify factors affecting outcomes. PubMed, Medline, Embase, and Cochrane databases were searched. Included studies reported implant survival by flap type. Results were pooled and survival was estimated with the Kaplan-Meier method. Variables affecting survival were assessed using Cox regression. Thirty-two of the 2631 articles retrieved were included, totaling 2626 implants placed into fibula, iliac crest, scapula, and radial forearm free flaps. Pooled survival showed 94% 5-year survival of implants in fibula and iliac crest with no difference between groups (P = .3). Factors effecting survival included radiotherapy (HR 2.3, 95% CI 1.2-4.6, P = .027) and malignant disease (HR 2.2, 95%CI 1.6-3.1, P < .001). Implant survival appears adequate across common flap types; however, there are limited numbers reported in less common flaps.

Three-Dimensional Finite Element Analysis of Osseointegrated Implants Placed in Bone of Different Densities With Cemented Fixed Prosthetic Restoration.

A key factor for a successful dental implant is the manner in which stresses are transferred to the surrounding bone. Strength of bone is directly related to its density. Maximum stresses are reported to be incurred by the crestal cortical bone surrounding the implant. Displacement of implants is significantly higher in soft cancellous bone than dense bone. Implants are often placed in bone of different densities to support fixed dental prostheses. This study was aimed at assessing stress and deformation generated by osseointegrated implants placed in bone of different densities on a cemented fixed prosthesis when subjected to static and dynamic loading. A 3-dimensional finite element analysis was done on a computer-aided design model simulating maxillary bone segment with 2 different bone densities (D2 and D4). The effect of loading was evaluated at the implant-bone interface, implant-abutment interface, abutment, implant abutment connecting screw, cementing medium, and fixed prosthesis. Stresses were calculated using von Mises criteria calibrated in megapascals and deformation in millimeters. These were represented in color-coded maps from blue to red (showing minimum to maximum stress/deformation), depicted as contour lines with different colors connecting stress/deformation points. The study found greater von Mises stress in D2 than D4 bone, and in D2 bone the component with higher stress was the implant. Deformation was greater in D4 than D2 bone, and in D4 bone the abutment-prosthesis interface showed more deformation.