Bone Preparation Research Articles

From Mechanical Machining Technology: A New Solution That Integrates Blades to the Implant to Control the Stress to the Peri-Implant Cortical Bone

Background: To prevent excessive compression of the cortical layer, which can lead to marginal bone loss, various companies have introduced specialized drills. However, these drills often lack the necessary precision, as the operator’s hand may neither be stable enough to prevent ovalization and over-widening nor precise enough to maintain coaxial alignment. Therefore, the aim of this study was to develop a device capable of achieving calibrated cortical preparation in terms of both dimension and coaxiality. Methods: A machining technology based on drilling principles was employed to create the device. Results: Nine blades were incorporated between the transmucosal neck and the implant threads, enabling the blades to cut the cortical bone coaxially during the implant insertion process. Conclusions: The primary goal of this study was to develop an implant capable of achieving calibrated cortical bone preparation, ensuring both precise dimensional control and coaxial alignment. This design incorporates integrated blades that allow for controlled cortical decompression, helping to manage radial compressive stresses during implant placement. Although the experimental studies cited were conducted independently of this research, they validate the functional efficacy of this implant design, demonstrating its ability to promote osseointegration and preserve marginal bone. The results suggest that this implant configuration holds the potential for improving clinical outcomes, particularly in cases where bone quality or density poses challenges to implant stability.

The Ethnoarchaeology of Pottery Tempers in the Bolivian Amazon: Two Indigenous Traditions of Paste Recipes with Preparations of Freshwater Sponge, Pottery Sherds, Bone, and Turtle Shell

ABSTRACT This article integrates ethnoarchaeological investigations of the pottery chaîne opératoire from two research projects conducted with Indigenous peoples of the Llanos de Moxos region in the Bolivian Amazon. Two distinct technological traditions of pottery temper are documented: freshwater sponge temper (cauixi) used by Cayubaba potters and ground turtle shell, bone, and pottery sherds employed by Tsimane' potters. Substantial information is provided on the composition of the distinctive tempers and pastes, the origin of materials, and their preparation, careful mixing into different recipes, and appearance in the finished product. Pottery temper and clay paste recipes distinguish the identity of potters within and between technological traditions in the region. Furthermore, this study contributes to the developing understanding of the importance of ceramics in Amazonian Indigenous ontologies. New questions and challenges are raised for the analysis of archaeological ceramics in Amazonia, one of the most culturally and linguistically diverse regions of the world.

Decorated Bone Tube Manufacture in Early Bronze Age Israel: Experimental Analysis of Bone Preparation and Incising

ABSTRACT Experimental replication of decorated bone tubes was carried out to determine possible methods of defleshing and to define the nature of linear cut-marks on the bones made by different cutting implements. These studies were carried out to interpret more precisely the production techniques for incised bone tubes recovered from Early Bronze Age (EB) contexts at the site of Tell el-Hesi dating to 2800–2700 bce (EBIIIA). Previous studies had assumed that the bones were incised using metal chisels found on-site, but the new experiments demonstrate that the incised lines were most likely made using denticulated metal (copper/bronze) saws. Modern cow metapodials were defleshed and then cut and sawn with different types of tools. Impressions were made of the experimental and archaeological incised lines and the impressions were studied using Scanning Electron Microscopy. The incised lines made using denticulated metal saws most closely match the incised lines of the ancient incised bone tubes.

QUALITATIVE ANALYSIS OF MAHISHADRAVAKA WITH SPECIAL REFERENCE TO LCMS STUDY

Introduction: Mahishadravaka, a renowned Ayurvedic proprietary medicine, has been historically used for its therapeutic properties. It is the arka preparation (distillation process) of Mahisha bone (bone of a buffalo), along with other herbal medicines. It is traditionally used for Vata vyadhies (diseases caused by Vata). Materials and Method: In this study, we conducted a comprehensive LCMS analysis and vitamin D3 and Calcium analyses of Mahishadravaka. Identification and characterisation of bioactive compounds were also aimed at. Result: Our findings reveal a diverse array of compounds with promising pharmacological activities, including Anti-inflammatory, antioxidant, anti-microbial, and anticancer properties. This article provides an overview of the identified compounds and their reported medicinal benefits, shedding light on the potential mechanisms underlying the therapeutic efficacy of Mahishadravaka. Conclusion: The LCMS of Mahishadravaka unveiled a rich array of bioactive compounds with significant pharmacological potential. The elucidation of the bioactive constituents paves the way for further research and development of novel therapeutic formulations based on Ayurvedic principles. These compounds encompass a broad spectrum of therapeutic activities, validating the traditional use of Mahishadravaka in Ayurvedic medicine. The findings from this study provide a scientific basis for the therapeutic efficacy of Mahishadravaka and underscore its potential for developing novel therapeutic interventions targeting various diseases.

Different intraoperative joint laxity patterns do not impact clinical outcomes in robotic-assisted medial unicompartmental knee replacement with 1-to-1 surface reconstruction.

Robotic-assisted technology in medial unicompartmental knee arthroplasty (mUKA) allows for customized adjustments of joint laxity through virtual preoperative component positioning before bone preparation. Nevertheless, the optimal balancing curve has yet to be delineated. This study sought to investigate if varying intraoperative knee laxity patterns had any impact on postoperative patient outcomes. A retrospective analysis was conducted on prospectively collected data from 326 fixed-bearing RAUKA procedures performed between 2018 and 2022 with a minimum 2-year follow-up. Patients were categorized into three cohorts based on intraoperative joint laxity patterns (millimetres of joint gap during valgus stress) imparted at 20°, 60°, 90°and 120° of knee flexion: cohort 1 < +0.5 mm (tight); cohort 2 between 0.6and 1.9 mm (physiologic); cohort 3 > 2 mm (loose). Wilcoxon and Kruskal-Wallis tests were conducted to assess patient-reported outcome measure(PROM) improvementsand preoperative and postoperative differences across the cohorts. A Spearman's test evaluated the correlation between knee balance at all degrees of flexion and preoperativeand postoperative HKA. No differences in preoperative and postoperative PROMs were identified across the cohorts (p > 0.05). All three cohorts with different joint laxity patterns showed a significant improvement in the postoperative PROMS (p < 0.05). The preoperative or postoperative limb alignment did not significantly affect clinical outcomes relative to different laxity patterns. No differences were found in the outcomes across different joint laxity patterns in robotic-assisted medial UKA using fixed-bearing mUKAs. There was no evident advantage for maintaining a closer to physiologic laxity compared to tighter or looser balancing. Level III therapeutic study.

Clinical Implementation of Tissue-Sparing Posterior Cervical Fusion: Addressing Market Access Challenges.

Background: The traditional open midline posterior cervical spine fusion procedure has several shortcomings. It can cause soft tissue damage, muscle atrophy, compromise of the lateral masses and painful prominent posterior cervical instrumentation or spinous process if there is dehiscence of the fascia. Additionally, patients frequently experience the rapid development of adjacent segment disease, which can result in the reemergence of debilitating pain and functional impairment. Clinical relevance: Tissue-sparing posterior cervical fusion is an alternative method for treating patients with symptomatic cervical degenerative disc disease. However, widespread clinical adoption has been challenged by ambiguity, misunderstandings and misinterpretations regarding appropriate procedural reimbursement coding. Technological advancement: The tissue-sparing posterior cervical fusion procedure was approved by the US Food and Drug Administration (FDA) in 2018 (CORUS™ Spinal System and CAVUX® Facet Fixation System (CORUS/CAVUX); Providence™ Medical Technology). This technique addresses the concerns with traditional spine fusion methods by achieving the stability and outcomes of posterior cervical fusion without the morbidity associated with significant muscle stripping in the traditional approach. This technology uses specialized implants and instrumentation to perform all of the steps required to facilitate bone fusion and provide stability while minimizing tissue disruption. The technique involves extensive bone preparation for fusion and placement of specialized stabilization implants that span the facet joint, promoting natural bone growth and fusion while reducing the need for extensive exposure. This procedure provides an effective, less invasive solution for patients with cervical degenerative disc disease. Reimbursement and coding clarity: The article provides a comprehensive rationale for appropriate reimbursement coding for tissue-sparing posterior cervical fusion. This is a critical aspect for the adoption and accessibility of medical technologies. This information is crucial for practitioners and healthcare administrators, ensuring that innovative procedures are accurately coded and reimbursed. Procedural details and clinical evidence: By detailing the procedural steps, instruments used and the physiological basis for the procedure, this article serves as a valuable educational resource for spine surgeons and payers to appropriately code for this procedure. Conclusions: The description of work for CORUS/CAVUX is equivalent to the current surgical standard of lateral mass screw fixation with decortication and onlay posterior grafting to facilitate posterior fusion. Thus, it is recommended that CPT codes 22600/22840 be used, as they best reflect the surgical approach, instrumentation, decortication, posterior cervical fusion and bone grafting procedures.

Tooth autotransplantation and resin composite reshaping as a multidisciplinary approach for treating dental agenesia: A 10-year follow-up.

This case report describes the multidisciplinary approach performed in a 9-year-old male patient with dental agenesia affecting teeth 21 and 22. Autotransplantation of the right upper second premolar with incomplete rhizogenesis to the missing area was combined with coronary reshaping with resin composite and orthodontic therapy. The treatment began with the extraction of the deciduous upper left central incisor, bone preparation for the recipient site of the donor tooth, atraumatic extraction of the right upper second premolar and immediate autotransplantation in the surgically prepared recipient site. Subsequently, sutures to reposition the flap and a rigid splint were performed. After 12 months, coronary reshaping of the autotransplanted tooth with resin composite was carried out. Orthodontic treatment involving the use of a fixed appliance was used to correct the interdental spaces and achieve adequate occlusion. Clinical and radiographic follow-up 10 years after tooth autotransplantation and 9 years after reshaping revealed partial obliteration of the pulp chamber, root resorption, ankylosis and the presence of endodontic treatment. The long-term outcomes highlighted that tooth autotransplantation represents a biologically and cost-effective procedure for replacing missing teeth in young patients, particularly in cases of incomplete rhizogenesis of the autotransplanted tooth. This case report discusses tooth autotransplantation and resin composite reshaping as viable and long-term clinical options for treating young patients with dental agenesis.

Peculiarities of the shape and size of the mandible and the lower dentition with taking into account gender and craniotype

The aim of the study: establishment of actual intravital craniometric characteristics of the shape and dimensions of the mandible and lower dentition of an adult person depending on gender and craniotype. Research materials and methods: the work used dry bone preparations of whole or fragmented human skulls of both sexes in the amount of 39 units, from the collection of the Department of Human Anatomy of the Kharkiv National Medical University, and the results of CT studies of the head of adult people without existing bone tissue pathologies, totaling 85 observations. The basis of establishing a craniotype is the principle of calculating the general facial or facial index, which allows classifying anatomical objects according to the shape of the head structure. Research results: the straight length of the mandible in adult leptoprosops males is from 88.5 mm to 102.4 mm, for women - from 86.3 mm to 100.7 mm; in mesoprosops men, this parameter gradually decreases to the level - from 81.3 mm to 95.7 mm, in women - from 80.7 mm to 94.9 mm; in euryprosops, the index is the smallest and ranges from 79.7 mm to 91.5 mm in males and from 78.5 mm to 90.8 mm in females. The opposite trend with significant ranges of variation is established for the angular width of the bone. Thus, in male leptoprosops, this parameter was determined from 84.6 mm to 97.5 mm, in female representatives - from 83.6 mm to 96.3 mm; in mesoprosops men, it increased from 89.1 mm to 105.3 mm, in women - from 87.9 mm to 103.1 mm; in euryprosops, regardless of sex, it reached its peak values, from 94.5 mm to 116.1 mm and from 92.7 mm to 114.1 mm, respectively. The height of the mandibular body also showed a certain dependence on the type of skull structure, in leptoprosops men it tended to the highest values ​​and was fixed at the level from 29.1 mm to 38.9 mm, as well as in women - from 27.5 mm to 37.8 mm; at the same time, in mesoprosops men, the size decreased from 25.9 mm to 36.3 mm, in women, in turn, from 24.6 mm to 35.1 mm; in euryprosops men, this parameter ranged from 22.3 mm to 33.1 mm, and next to women - from 21.9 mm to 31.9 mm, it was at the level of the lowest indicators. When analyzing such a complex and multidirectional parameter as the arch of the mandible, it was also possible to obtain a characteristic of its dependence on the type of structure of the facial department of the skull. It was established that the range with the smallest values ​​of the length of the arc is characteristic of leptoprosops, ranging from 135.8 mm to 149.4 mm in males and from 133.5 mm to 147.3 mm in females; average indices are characteristic of men - from 139.1 mm to 154.6 mm and women - from 136.4 mm to 151.2 mm with a mesoprosopic craniotype; in euryprosops of both sexes, the index tends to the greatest values ​​at the level of 141.2 mm to 158.3 mm and from 139.7 mm to 155.7 mm, respectively. Conclusions: the main craniometric parameters of the mandible are significantly dependent on the type of structure of the facial department of the skull. Thus, the leptoprosopic craniotype is characterized by maximum values ​​of longitudinal and height dimensions with minimal indicators of width and arc length. Mesoprosops are characterized by the definition of intermediate, averaged values ​​equidistant from marginal, terminal forms. In representatives with the euryprosopic type of skull structure, a significant decrease in the length and height of the jaw with a significant increase, up to the maximum values, width and length of the arch was observed. At the same time, unlike leptoprosops, which had a shortened and pointed arch, in euryprosops, the arch tended to be smoothed and lengthened. The assessment by sex leads to the fact that all sizes of the lower jaw predominate in men, but, nevertheless, a certain number of differences in indicators were within the limits of statistical error, which does not allow making absolute conclusions in this matter

Promising short-term outcomes of free-hand burring technique to implant second-generation metaphyseal cone in Asian knees – a case series

BackgroundThe second-generation metaphyseal cone was useful in managing bone defects in revision knee arthroplasty. However, due to the anatomical constraints in Asian osteometry, the authors utilized a novel free-hand burring technique instead of cannulated reaming for bone preparation. We reported the short-term outcomes of our surgical techniques specific to Asian osteometry.MethodsWe conducted a case series by consecutively recruiting 13 female and 12 male patients (involving 25 knees), with a mean age of 71 years (range, 54–88 years). The patients underwent revision total knee arthroplasty during the period from April 2017 to June 2022. Twenty-three tibial cones and 4 femoral cones using free-hand burring technique were implanted. The mean follow-up duration was 51 months (range 18–80 months). Due to the relatively small bone size and meta-diaphyseal center mismatch in the Asian knees, the free-hand burring technique instead of the cannulated reaming technique was adopted in preparing for cone implantation. The clinical outcomes were knee ranges of motion, the Knee Society Knee scores (KSS), end-of-stem pain, infection, and the need for revision surgery. The radiological outcomes included osteointegration, fracture, and loosening.ResultsMean knee range of motion improved from 83 degrees (range 0°–120°) preoperatively to 106 degrees (range 60°–125°) postoperatively (P < 0.001). Mean KSS improved significantly from 29 (range 0–70) to 69 (range 5–100) (P < 0.001). All cones were osteointegrated. One case had transient end-of-stem pain, two developed intraoperative minor femoral fractures and one suffered from recurrent infection that did not require cone revision. Cone revision-free survivorship was 100%. There was no aseptic loosening.ConclusionsThe second-generation cone implanted with free-hand burring bone preparation yielded promising short-term outcomes in Asian knees.

Evaluation of anatomical and radiological measurements of the proximal phalanx of the horse

When performing osteosynthesis by screw fixation, it is important to carry out operational planning (choosing the screw of the optimal length and diameter). Choosing the optimal osteosynthesis tactics and the correct screw size allows you to stimulate regeneration and prevent possible complications. The X-ray examination method is included in the mandatory criterion of preoperative examination, which allows you to determine the size of the deformation and bone parameters. The present study is based on the hypothesis that the lifetime X-ray measurement of the bone of the proximal phalanx of a horse (longitudinal and transverse dimensions of the proximal and distal epiphysis and diaphysis, bone length), allows us to justify the size and technique of fixing the screw in the treatment of fractures. Morphometric studies included macroscopic dissection; morphometry of bone preparations; Xray measurement of the putus bone; documentation of the data obtained, photographing. A morphometric study was performed on 20 bone preparations (10 thoracic and 10 pelvic) and 40 X-ray images (20 in lateromedial and 20 in dorso-palmar/plantar projections) of the proximal phalanx of the horse. As a result of the work performed, it was found that the variability of parameters (longitudinal and transverse size of the proximal epiphysis, longitudinal and transverse size of the distal epiphysis; the longitudinal and transverse size of the diaphysis, bone length) of the fetal bone of the thoracic and pelvic limbs in horses for average values has no significant deviations (up to 1%), while the differences between the minimum and maximum values range from 20.0% to 66.6% for values obtained by anatomical method; from 12.2% and 33.3% for the Xray method.

Pulsed lavage is associated with better quality of bone-cement-implant interface in knee arthroplasties (TKA/UKA) compared to syringe lavage in vitro; however, clinical data are missing: A systematic review.

The purpose of this systematic review is to analyse the available literature to ascertain the optimal method of bone preparation to improve the quality of bone-cement-implant interface with either pulsed lavage or syringe lavage in both total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA). A comprehensive search was conducted across MEDLINE, Scopus and Embase databases until July 2023. Both inclusion and exclusion criteria were clearly stated and used to identify all the published studies. Subsequent screening throughout the title, abstract and full text was made, followed by complete critical appraisal and data extraction. This sequential process was performed by two reviewers independently and summarised following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines). A quality assessment of the systematic review was performed according to the Quality Appraisal for Cadaveric Studies scale (QUACS), reaching a quality level ranging from 69% to 85%. A total of 10 articles, out of 47, nine biomechanical cadaveric studies and one human clinical study were analysed. A total of 196 UKA tibial components, 74 patellar components, 36 TKA tibial components and 24 UKA femoral components were retrieved, and a high level of heterogeneity resulted overall. The pulsed lavage group showed better cement penetration and higher pull-out force than the syringe lavage group; a higher interface temperature was also found in the pulsed lavage group. No differences were found regarding tension ligament forces between the groups. Our systematic review suggests that pulsed lavage is superior to syringe lavage in terms of the quality of bone-cement-implant interface in knee arthroplasties (TKA/UKA). However, translation of these results from cadaveric studies to individual clinical settings may be hazardous; therefore, clinical in vivo prospective studies are highly needed. PROSPERO CRD number CRD42023432399. Level III.

Long-Term Clinical Outcomes of 3D-Printed Subperiosteal Titanium Implants: A 6-Year Follow-Up.

As an alternative to regenerative therapies, numerous authors have recently proposed bringing back subperiosteal implants. The aim of the study was to present our clinical experience with a subperiosteal jaw implant that needs minimal bone preparation and enables the rapid implantation of prosthetic teeth in edentulous, atrophic alveolar bone. The research included 36 complete or partial edentulous patients (61 subperiostal implants) over a period of 6 years. To create the patient-specific subperiostal implants design, DentalCAD 3.0 Galway software (exocad GmbH, Darmstadt, Germany) was used and fabricated with a Mysint 100 (Sisma S.p.A., Piovene Rocchette, Italy) by titanium alloy powder. The results showed that only 9 of the 36 cases were successful at 6-year follow-up, while 27 cases had complications, including exposure of the metal frame (early or delayed), mobility of the device prior to the first 4-6 months, and late mobility due to recurrent infections and progressive structure exposure; 1 case failed for reasons unrelated to the device. This study indicated that the prudent application of fully customized subperiosteal jaw implants is a dependable alternative for the dental rehabilitation of atrophic edentulous cases that necessitate bone grafts for traditional fixed dental implant solutions.

Preparation, Optimization, and Characterization of Bovine Bone Gelatin/Sodium Carboxymethyl Cellulose Nanoemulsion Containing Thymol.

The aim of this study is to produce a biodegradable food packaging material that reduces environmental pollution and protects food safety. The effects of total solids content, substrate ratio, polyphenol content, and magnetic stirring time on bovine bone gelatin/sodium carboxymethylcellulose nanoemulsion (BBG/SCMC-NE) were investigated using particle size, PDI, turbidity, rheological properties, and zeta potential as evaluation indexes. The micro, structural, antioxidant, encapsulation, and release properties were characterized after deriving its optimal preparation process. The results showed that the nanoemulsion was optimally prepared with a total solids content of 2%, a substrate ratio of 9:1, a polyphenol content of 0.2%, and a magnetic stirring time of 60 min. SEM showed that the nanoemulsion showed a dense and uniform reticulated structure. FTIR and XRD results showed that covalent cross-linking of proteins and polysaccharides altered the structure of gelatin molecular chains to a more compact form but did not change its semi-crystalline structure. DSC showed that the 9:1 BBG/SCMC-NE had a higher thermal denaturation temperature and greater thermal stability, and its DPPH scavenging rate could reach 79.25% and encapsulation rate up to 90.88%, with excellent slow-release performance. The results of the study provide basic guidance for the preparation of stable active food packaging with excellent properties.

Online training for hearing implant surgery : Anew approach to otological training.

Education in microsurgery of the ear includes staged training to allow for mastering of the complex microsurgical procedures, particularly in the context of middle ear reconstruction and cochlear implantation. Traditional surgical training includes temporal bone preparations by cadaver dissection and supervised operating room practice. As these on-site trainings are limited, there is aneed to broaden education facilities in an on-line format. Therefore, afirst basic on-line training for otosurgery was developed. The system consists of an artificial temporal bone model together with aset of basic surgical instruments and implant dummies. As an essential part of the training kit, ahigh-resolution camera set is included that allows for connection to avideo streaming platform and enables remote supervision of the trainees' surgical steps by experienced otological surgeons. In addition, apre-learning platform covering temporal bone anatomy and instrumentation and pre-recorded lectures and instructional videos has been developed to allow trainees to review and reinforce their understanding before hands-on practice. Over the three courses held to date, 28participants with varying levels of prior surgical experience took part in this otological surgical training program. The immediate feedback of the participants was evaluated by means of aquestionnaire. On this basis, the high value of the program became apparent and specific areas could by identified where further refinements could lead to an even more robust training experience. The presented program of an otosurgical online training allows for basal education in practical exercises on aremote system. In this way, trainees who have no direct access to on-site instruction facilities in ear surgery now have the chance to start their otosurgical training in an educational setting adapted to modern technologies.

Biomechanical Comparison of Impaction Techniques and Cross-Sectional Femoral Stem Shapes for Cementless Total Hip Arthroplasty.

Traditional mallet broaching and stem seating in cementless total hip arthroplasty (THA) can result in femoral stem misalignment, potentially reducing implant longevity. This study aimed to compare the pullout strength of cementless THA femoral stems with different cross-sectional designs achieved through the powered impactor method versus the traditional mallet method. The authors utilized 24 polyurethane foam femurs and two femoral bone preservation stems with different proximal cross-sectional shapes (double taper: ACTIS®, size 5; flat taper: TRI-LOCK®, size 5). A single orthopedic surgeon broached each femur from size 0 to size 5 using either the powered impactor or mallet impaction methods. Broaching time and component implantation times were recorded. A load-to-failure pullout strength test was conducted, and the ultimate pullout load was recorded. The broaching time for the TRI-LOCK® stem showed a statistically significant difference between the two impaction methods (powered: 37±7 seconds, mallet: 75±29 seconds, F[3, 20] = 4.56, p = 0.002), but no statistically significant difference was detected for the ACTIS® stem between the two impaction methods (powered: 47±22 seconds, mallet: 59±9 seconds, F[3, 20] = 4.56, p = 0.304). There was a statistically significant difference in pullout strength between the two impaction groups, and this strength was influenced by the implant cross-sectional shape (ACTIS®: 774±75N versus 679±22N, F(3,20) = 16.38, p = 0.018; TRI-LOCK®: 616±57N versus 859±85N, F(3, 20) = 16.38, p <0.001). The technique used for femoral bone preparation (powered impactor versus mallet) and the cross-sectional design of the cementless femoral stem are crucial factors that affect initial stem stability and operation time.

Small deviations between planned and performed bone cuts using a CT-based robotic-arm-assisted total knee arthroplasty system.

Computed tomography (CT)-based robotic system for total knee arthroplasty (TKA) has shown improved accuracy compared to conventional. This study was designed to(1) confirm the accuracy of the robotic system in achieving the planand (2) establish the alignment and positioning deviation between final components and planning, by measuring the discrepancy between final implant alignment and the corresponding planned cut. Ninety-six cementless robotic-arm assisted (RA) TKAs were assessed. Bone resections were performed using the haptically controlled robotic arm. Alignment in the coronal and sagittal plane and resection depth of the distal femoral and proximal tibial cuts were recorded with a navigation planar probe. After final components were impacted, the probe was positioned on each implant surface to determine its alignment and positioning. The mean tibial resections and implanted tibial component's positioning were 0.4 mm (standard deviation, SD: 0.6) and 0.9 mm (SD: 0.8), respectively, higher than planned (p < 0.01). The tibial sagittal cut had 19/96 cases (19.8%) of ±1° outliers from plan. In 40/96 cases (41.7%), the tibial component was more prominent than planned of more than 1 mm. The mean femoral resections and impacted femoral component's positioning was 0.1 mm (SD: 0.8) and 0.2 mm (SD: 0.7), respectively, higher than planned. In 23/96 cases (24.0%), the femoral sagittal cut and femoral component coronal alignment deviated more than ±1° from plan. The computed tomography-based robotic-assisted TKA system showed good accuracy regarding bone preparation and component's positioning relative to the planning. Cementless tibial component impaction resulted in the most deviation from plan, with a large proportion of cases resulting in being more prominent than planned. Level III.

In vitro Preparation of Dry Bones from Remnants of Dissected Cadavers: An Effective Low-cost Method of Recycling Remnants of Human Cadavers

Background: Human bones are an essential part of medical education. Objectives: This study outlines a new method developed by the Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura, for processing human bones from cadaver waste. Subjects and Methods: The bones were disarticulated, cleaned of soft tissues, and boiled with potassium hydroxide. Afterward, they were deposited in an aerating system with a water pump, covered with a soil mixture, and were aerated to provide fresh air, and the humidity of the soil was monitored. After 4 months of soil treatment, the bones were exhumed, boiled, air-dried, and varnished. Results: This method produced good-quality bones within a shorter time using less resources. It helped generate more bones and halve the cadaver waste cost. Conclusion: The technique can easily be adopted to produce human bones, even within a small space, in less time and with less labor force.

Micro CT Analysis and 3D Modelling of Fluid Permeability of Talar Subchondral Bone After Marrow Stimulation Techniques Demonstrates Superiority of Nanofracture Over Microfracture and Fine Wire Drilling

Introduction/Purpose: The aim was to compare different bone marrow stimulation techniques and consequent fluid permeability of subchondral bone by assessing flow of radiopaque contrast agent using μCT image analysis and 3D modelling. Methods: Donated human tali specimens (n=12) were prepared by creating separate matched 10mm diameter chondral defects in each. Each defect underwent one of three surgical techniques: fine wire drilling, nanofracture or microfracture, addition of radiopaque contrast agent and imaged using a clinical μCT scanner. Using Slicer 3D software each μCT scan was segmented for bone and contrast agent regions in each surgical site of each sample. Each site was resolved into a cylinder and the ratio of segmented pixels of contrast agent against bone calculated. Results: μCT analysis indicated that 8/12 nanofracture regions demonstrated enhanced flow of contrast to at least the depth of the fracture site, with some additional lateral flow also observed. 8/12 microfracture regions demonstrated flow of contrast agent localised to the fracture site and preferential flow laterally. Only 1/12 samples with fine wire drilling demonstrated any fluid flow. In 11/12 samples that showed no permeation of contrast agent, a residual layer of contrast agent on the chondral surface was seen. Segmentation of each sample site showed a significant increase (n=12, p&lt; 0.05) in fluid flow of the contrast agent in the nanofracture sites (11%) compared to microfracture (5%) and fine wire drilling (2%). Conclusion: Nanofracture showed significantly improved fluid permeability throughout the surrounding trabecular structure, when compared to microfracture and fine wire drilling. Microfracture allowed some fluid flow, but only confined to the immediate area around the fracture site, while fine wire drilling allows very little fluid flow at all. This study suggests that nanofracture should perhaps be the preferred mode of subchondral bone preparation for osteochondral lesions of the talus. Quantitative measurement of contrast permeability into talar subchondral bone by technique Nanofracture showed significantly improved fluid permeability throughout the surrounding trabecular structure, when compared to microfracture and fine wire drilling

CHARACTERISTICS OF THE SHAPE AND SIZE OF THE MAXILLA AND UPPER DENTITION DEPENDING ON GENDER AND CRANIOTYPE

The analysis of relevant information sources provides a conclusion about the need to conduct new studies of the intravital range of craniometric characteristics of the structures of the facial skeleton, taking into account gender and existing types of skull structure. The aim of our study was to establish the current intravital craniometric characteristics of the shape and dimensions of the maxilla and upper dentition of an adult person, depending on gender and craniotype. The material of the study was dry bone preparations of whole or fragmented human skulls of both sexes in the amount of 39 units, from the collection of the Department of Human Anatomy of KNMU, and the results of CT studies of the heads of adult person without existing bone tissue pathologies, totaling 85 observations. The basis of establishing a craniotype is the principle of calculating the general facial or facial index, which allows classifying anatomical objects according to the shape of the head structure. As a result of the research, it was established that the predominance of longitudinal and height parameters of the maxilla and the upper dentition is inherent in the leptoprosopic type of skull structure. Intermediate, averaged values of all parameters are observed in the group with mesoprosopic craniotype. People with the euryprosopic type are characterized by a signifi cant predominance of transverse, latitudinal dimensions. In addition, when analyzing the obtained data set, a slight predominance of craniometric indicators in male representatives was observed, for almost all sizes, however, a signifi cant majority of the diff erences were within the limits of statistical error, which does not make it possible to draw conclusions about the existing diversity based on gender.

Online training for hearing implant surgery : Anew approach to otological training. German version

Education in microsurgery of the ear includes staged training to allow for mastering of the complex microsurgical procedures, particularly in the context of middle ear reconstruction and cochlear implantation. Traditional surgical training includes temporal bone preparations by cadaver dissection and supervised operating room practice. As these on-site trainings are limited, there is aneed to broaden education facilities in an on-line format. Therefore, afirst basic on-line training for otosurgery was developed. The system consists of an artificial temporal bone model together with aset of basic surgical instruments and implant dummies. As an essential part of the training kit, ahigh-resolution camera set is included that allows for connection to avideo streaming platform and enables remote supervision of the trainees' surgical steps by experienced otological surgeons. In addition, apre-learning platform covering temporal bone anatomy and instrumentation and pre-recorded lectures and instructional videos has been developed to allow trainees to review and reinforce their understanding before hands-on practice. Over the three courses held to date, 28participants with varying levels of prior surgical experience took part in this otological surgical training program. The immediate feedback of the participants was evaluated by means of aquestionnaire. On this basis, the high value of the program became apparent and specific areas could by identified where further refinements could lead to an even more robust training experience. The presented program of an otosurgical online training allows for basal education in practical exercises on aremote system. In this way, trainees who have no direct access to on-site instruction facilities in ear surgery now have the chance to start their otosurgical training in an educational setting adapted to modern technologies.