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Background: Clinical understanding of the obturator nerve's cutaneous and motor branches is crucial for performing effective obturator nerve blocks, particularly for procedures involving the thigh and hip. Literature and anatomical references report highly variable patterns of the frequency and cutaneous distribution of obturator nerve innervation.This study examines the frequency and distribution of the cutaneous branch of the anterior ramus of the obturator nerve (cb-ar-ON) and assesses the most effective anatomical sites for nerve blockade., Methods: Dissections were conducted on 14 sides from eight cadavers to identify the presence, branching pattern and innervation areas of the cb-ar-ON. Ultrasound-guided injections of low-volume dye were performed proximally between the adductor longus and gracilis muscles and distally near the great saphenous vein to assess optimal targeting., Results: cb-ar-ON were found in 43% of cadaveric sides, branching off the anterior ramus of the obturator nerve 6-10 cm distal to the inguinal ligament. When present, the cb-ar-ON innervated a 4-9 cm 2 area in the posteromedial popliteal fossa. Proximal ultrasound-guided blocks targeting the area between the adductor longus and gracilis muscles effectively stained the cb-ar-ON in 100% of cases where the branch was present., Conclusion: The cb-ar-ON provides variable and limited cutaneous innervation, appearing in 43% of cases, primarily in the posteromedial popliteal fossa. Effective blockade can be achieved with a proximal approach between the adductor longus and gracilis muscles.These findings suggest that clinical evaluation of obturator nerve block based on cutaneous anesthesia is unreliable., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2025. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Background: The quest for a single nerve block to anesthetize all anterior hip articular nerve branches has long been a challenge for anesthetists, particularly in targeting the obturator nerve (ON). The FRONT block (Femoral Rami Obturator Nerve Trunk) is a newly developed dual-injection technique providing comprehensive anesthetic coverage of the anterior hip joint by targeting both the sensory femoral rami and the ON trunk., Methods: 15 intact cadaveric sides from eight embalmed cadavers were dissected after FRONT block administration with one injection and two dye deposits in the iliopsoas plane and in the subpectineal compartment under dynamic ultrasonography. The primary outcome was dye spread to the sensory hip articular branches of the femoral nerve (FN) and the ON trunk evaluated during the gross anatomical dissection. Secondary outcomes included identifying landmarks for accurate injection of dye and measuring the distance from the needle trajectory to the femoral and the lateral femoral cutaneous nerves (LFCN)., Results: In 86.7% of cadaver sides, the FRONT block successfully covered both the sensory femoral rami and the ON trunk. The injection was performed 6.7 cm (SD 1.6) distal to the anterior superior iliac spine with a medial deviation of 1.8 cm (SD 2.1). The average distance from the needle trajectory to the FN was 0.8 cm (SD 0.4) and 3.7 (SD 2.1) cm to the LFCN., Conclusion: The FRONT block offers reliable coverage of the anterior hip joint and capsule. Proficiency in ultrasound-guided regional anesthesia is important during clinical applications., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2025. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Purpose: This study aims to map the point of emergence of the lateral cutaneous branch of the fourth intercostal nerve in both sexes, addressing gaps in the current literature. The findings are intended to support surgeons in restoring breast function by providing precise anatomical data, regardless of the specific surgical technique employed., Methods: An anatomical study was conducted using 50 sides from 25 formalin-preserved full-body donors, with equal representation of male and female subjects. Measurements were taken to determine the fascial point of emergence of the lateral cutaneous branch of the fourth intercostal nerve relative to the anterior axillary line and the transverse line. Multiple linear regression models were applied to evaluate the influence of variables such as sex, height, and side., Results: Our findings indicate that the fascial point of emergence of the lateral cutaneous branch of the fourth intercostal nerve is consistently located within 20 to 24 mm relative to the transverse line in 37 (74%) cases, and within 4 to 10 mm relative to the anterior axillary line in 39 (78%) cases, regardless of sex, height, or side. The multiple linear regression analysis showed no significant correlation between these variables and the position of the point of emergence (p > 0.05)., Conclusion: These results provide surgeons with a practical tool for nerve coaptation during breast reconstruction, showing that sex and height do not affect the anatomical localization of the point of emergence. Precise knowledge of this point can improve surgical accuracy and enhance sensory recovery, leading to better patient outcomes., Competing Interests: Declarations. Ethics approval: This study was performed in line with the principles of the Declaration of Helsinki. Written informed consent was obtained by the Institute of Clinical and Functional Anatomy (Medical University of Innsbruck) before death from all body donors included in the study. Ethics approval was waived by the local Ethics Review Board of the Medical University of Innsbruck in view of the exclusive use of specimens from body donors. Consent to publication: Written informed consent was obtained by the Institute of Clinical and Functional Anatomy (Medical University of Innsbruck) before death from all body donors included in the study. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: Although sciatic nerve (SN) injury is relatively rare, it is a devastating complication after primary and revision total hip arthroplasty (THA). Therefore, precise localization of the SN is essential for arthroplasty surgeons., Methods: We dissected 50 hemipelves from formalin-fixed cadavers. The course and location of the sciatic nerve were investigated in relation to different approaches for THA with the help of anatomical landmarks like the greater trochanter (GT), the iliac tubercle, the ischial tuberosity (IschT), the infrapiriform foramen, and the suprapiriform foramen., Results: We found and exposed the sciatic nerve in all 50 specimens with no sex-specific differences. No SN was encountered up to 22 mm posterior from the GT. The zone affording the highest probability of finding the nerve was posterior to the GT between 32 and 55 mm in 39 (78%) cases, thus defining a danger zone for different approaches for the THA., Conclusion: Special care should be taken with posterior and deep instrument placement between the GT and IschT during THA. Moreover, manipulations in the proximal third of the posterior approach reaching deep and posteriorly should be performed with the utmost care., (© 2024. The Author(s) under exclusive licence to SICOT aisbl.)

Background: Femoral nerve (FN) injury is noted as a serious neurological complication following total hip arthroplasty performed via a direct anterior approach (DAA). Therefore, we aimed to clarify the anatomical course of the FN around the acetabular rim and in relation to retractor placement during DAA., Methods: According to standard protocol, a DAA for total hip arthroplasty was performed on 69 hemipelves from formalin-preserved full-body donors. The surgery was halted after retractor placement at the anterior part of the acetabulum. Then dissection was performed to expose the FN and the iliopsoas muscle. Various measurements were taken using a reference line from the anterior superior iliac spine to the acetabulum's center. A total of 6 measurement points, one every 30° from 0° to 150° along the reference line were used to determine the association between the FN and the retractor tip (RT) and the anterior acetabular rim., Results: The mean distance from the RT to the FN was 22.5 millimeters (mm). The distance from the FN to the anterior acetabular rim decreased from 0 to 90°, where it was 18.8 mm, before increasing again to 27.3 mm at 150°., Conclusions: In our cadaveric study, the FN was within 11 to 36 mm of the RT. Second, we found the FN to be closest to the anterior acetabular rim at 90° and 120°. Accordingly, special care should be taken during retractor placement, and if possible, placement at 90° and 120° avoided., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Iatrogenic vascular injury during total hip arthroplasty (THA) is rare, reported at rates of 0.05 to 0.3%, but a potentially limb-threatening and life-threatening complication. We aimed to describe safe and danger zones for the superior gluteal vessel bundle (SGV bundle) with reference to different THA approaches., Methods: There were 27 formalin-fixed cadavers with 49 hemipelves dissected. The course and distribution of the SGV bundle were investigated with the help of anatomical landmarks like the greater trochanter, the iliac tubercle (IT), and the ischial tuberosity., Results: We found and exposed the SGV bundle in all 49 specimens with no sex-specific differences. No SGV bundle was encountered up to 28 mm from the greater trochanter and up to 16 mm below the IT. The zone with the highest probability of finding the vessels was 25 to 65 mm below the IT in 39 (80%) cases - defining a danger zone (in relation to the skin incision) in the proximal fourth for the direct anterior approach, in the proximal half for the antero-lateral approach, in the proximal fifth for the direct lateral approach, and almost no danger zone for the posterior approach., Conclusions: Special care in proximal instrument placement should be taken during THA. When extending one of the surgical approaches, manipulations in the proximal, cranial surgical window should be performed with the utmost care to avoid SGV bundle injury., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hands-on courses utilizing preserved human tissues for educational training offer an important pathway to acquire basic anatomical knowledge. Owing to the reevaluation of formaldehyde limits by the European Commission, a joint approach was chosen by the German-speaking anatomies in Europe (Germany, Austria, Switzerland) to find commonalities among embalming protocols and infrastructure. A survey comprising 537 items was circulated to all anatomies in German-speaking Europe. Clusters were established for "ethanol"-, formaldehyde-based ("FA"), and "other" embalming procedures, depending on the chemicals considered the most relevant for each protocol. The logistical framework, volumes of chemicals, and infrastructure were found to be highly diverse between the groups and protocols. Formaldehyde quantities deployed per annum were three-fold higher in the "FA" (223 L/a) compared to the "ethanol" (71.0 L/a) group, but not for "other" (97.8 L/a), though the volumes injected per body were similar. "FA" was strongly related to table-borne air ventilation and total fixative volumes ≤1000 L. "Ethanol" was strongly related to total fixative volumes >1000 L, ceiling- and floor-borne air ventilation, and explosion-proof facilities. Air ventilation was found to be installed symmetrically in the mortuary and dissection facilities. Certain predictors exist for the interplay between the embalming used in a given infrastructure and technical measures. The here-established cluster analysis may serve as decision supportive tool when considering altering embalming protocols or establishing joint protocols between institutions, following a best practice approach to cater toward best-suited tissue characteristics for educational purposes, while simultaneously addressing future demands on exposure limits., (© 2023 The Authors. Anatomical Sciences Education published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

Profound knowledge of nerve variations is essential for clinical practice. It is crucial for interpreting the large variability of a patient's clinical presentation and the different mechanisms of nerve injury. Awareness of nerve variations facilitates surgical safety and efficacy. Clinically significant anatomical variations can be classified into two main groups: variability in the course of the nerve and variability of structures surrounding the nerve. In this review article we focus on the most common nerve variants of the upper extremity and their clinical relevance., Competing Interests: None declared., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Ionizing radiation is necessary for diagnostic imaging and deciding the right radiation dose is extremely critical to obtain a decent quality image. However, increasing the dosage to improve the image quality has risks due to the potential harm from ionizing radiation. Thus, finding the optimal as low as diagnostically acceptable (ALADA) dosage is an open research problem that has yet to be tackled using artificial intelligence (AI) methods. This paper proposes a new multi-balancing 3D convolutional neural network methodology to build 3D multidetector computed tomography (MDCT) datasets and develop a 3D classifier model that can work properly with 3D CT scan images and balance itself over the heavy unbalanced multi-classes. The proposed models were exhaustively investigated through eighteen empirical experiments and three re-runs for clinical expert examination. As a result, it was possible to confirm that the proposed models improved the performance by an accuracy of 5% to 10% when compared to the baseline method. Furthermore, the resulting models were found to be consistent, and thus possibly applicable to different MDCT examinations and reconstruction techniques. The outcome of this paper can help radiologists to predict the suitability of CT dosages across different CT hardware devices and reconstruction algorithms. Moreover, the developed model is suitable for clinical application where the right dose needs to be predicted from numerous MDCT examinations using a certain MDCT device and reconstruction technique.

Objectives: As-low-as-diagnostically-acceptable (ALADA) doses are substantially lower than current diagnostic reference levels. To improve dose management, a reference quality approach was tested in which phantom quality metrics of a clinical ALADA dose reference protocol were used to benchmark potential ALADA dose protocols for various scanner models., Methods: Spatial resolution, contrast resolution, contrast-to-noise ratio (CNR) and subjective noise and sharpness were evaluated for a clinical ALADA dose reference protocol at 80 kV and 40 mA (CTDIvol 2.66 mGy) and compared with test protocols of two CT scanners at 100 kV and 35 mA (3.08-3.44 mGy), 80 kV and 54-61 mA (2.65 mGy), 80 kV and 40 mA (1.73-1.92 mGy), and 80 kV and 21-23 mA (1.00-1.03 mGy) using different kernels, filtered backprojection and iterative reconstructions. The test protocols with the lowest dose showing quality metrics non-inferior to the reference protocol were verified in a cadaver study by determining the diagnostic accuracy of detection of maxillofacial fractures and CNR of the optical nerve and rectus inferior muscle., Results: 36 different image series were analysed in the phantom study. Based on the phantom quality metrics, potential ALADA dose protocols at 1.73-1.92 mGy were selected. Compared with the reference images, the selected protocols showed non-inferiority in the detection and classification of maxillofacial fractures and non-inferior CNR of orbital soft tissues in the cadaver study., Conclusions: Reference quality metrics from clinical ALADA dose protocols may be used to guide selection of potential ALADA dose protocols of different CT scanners.

The functions of the subclavius muscle (SM) are described as stabilization of the sternoclavicular joint (SCJ) and resisting elevation of the lateral end of the clavicle. During systematic cadaveric dissections, we observed additional fibrous structures, previously described as variants of the anatomy, extending from the SM and inserting into the coracoid process (CP). Due to the high incidence of these structures in our dissections, we hypothesized that the attachment at the CP is more common than appreciated and that, as a corollary, the function of the SM was (or has been) more complex than simply depressing the clavicle and generating stability at the SCJ. For our investigation, fifty-two upper extremities of 26 human cadavers were dissected. The SM was demonstrated from costal to clavicular attachment. We documented additional fibrous structures apparently derived from the SM inserting into the CP. Measurements of the length of the SM, the length of its attachment, and the length of the clavicle were taken in situ, with the specimens supine and the upper extremity in the anatomical position. Variations in the anatomy of the SM and its coracoidal attachment were recorded, and potential correlations were investigated. For documentation purposes photographs and video sequences of passive motion of the shoulder girdle of the specimens were taken. In 49 of the 52 specimens we found additional fibrous structures passing from the SM to the CP. We differentiated three types: (1) a strong cord-like structure; (2) a small or thin cord-like structure or structures; and (3) a planar twisted sheet-like structure. The SM and its extension to the CP appears to contribute to a 'functional scapular suspension system' together with the other muscles enveloped by the clavipectoral fascia (pectoralis minor, coracobrachialis and the short head of the biceps brachii). This system assists in the control of the position of the scapula in relation to the thorax, particularly in elevated positions of the upper extremity. We speculate that the differentiation of the fibrous structure depends on the functional demands of the individual. Level of Evidence: Basic science study., (© 2021 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)

Purpose: An auditory brainstem implant (ABI) represents an alternative for patients with profound hearing loss who are constrained from receiving a cochlear implant. The positioning of the ABI electrode influences the patient's auditory capacity and, therefore, quality of life and is challenging even with available intraoperative electrophysiological monitoring. This work aims to provide and assess the feasibility of visual-spatial assistance for ABI positioning., Methods: The pose of the forceps instrument that grasps the electrode was electromagnetically navigated and interactively projected in the eyepieces of a surgical microscope with respect to a target point. Intraoperative navigation was established with an experimental technique for automated nasopharyngeal patient registration. Two ABI procedures were completed in a human specimen head., Results: An intraoperative usability study demonstrated lower localization error when using the proposed visual display versus standard cross-sectional views. The postoperative evaluations of the preclinical study showed that the center of the electrode was misplaced to the planned position by 1.58 mm and 3.16 mm for the left and the right ear procedure, respectively., Conclusion: The results indicate the potential to enhance intraoperative feedback during ABI positioning with the presented system. Further improvements consider estimating the pose of the electrode itself to allow for better orientation during placement., (© 2021. The Author(s).)

Objective: Repeated computed tomography (CT) is essential for diagnosis, surgical planning and follow-up in patients with middle and inner ear pathology. Dose reduction to "as low as diagnostically acceptable" (ALADA) is preferable but challenging. We aimed to compare the diagnostic quality of images of subtle temporal bone structures produced with low doses (LD) and reference protocols (RP)., Methods: Two formalin-fixed human cadaver heads were scanned using a 64-slice CT scanner and cone-beam CT (CBCT). The protocols were: RP (120 kV, 250 mA, CTDIvol 83.72 mGy), LD1 (100 kV, 80 mA, CTDIvol 26.79 mGy), LD2 (100 kV, 35 mA, CTDIvol 7.66 mGy), LD3 (80 kV, 40 mA, CTDIvol 4.82 mGy), and CBCT standard protocol. Temporal bone structures were assessed using a 5-point scale., Results: A median score of ≥2 was achieved with protocols such as the tendons of m. tensor tympani (RP/LD1/LD2/CBCT) and m. stapedius (CBCT), the incudostapedial joint (RP/LD1/CBCT), the incudomalleolar joint (RP/LD1/LD2/CBCT), the stapes feet (RP/LD1/CBCT), the stapes head (RP/LD1/LD2/CBCT), the tympanic membrane (RP/LD1/LD2/CBCT), the lamina spiralis ossea (none), the chorda tympani (RP/LD1/CBCT), and the modiolus (RP/LD1/LD2/CBCT). Adaptive statistical iterative reconstructions did not show advantages over the filtered back projection., Conclusions: LD protocols using a CTDIvol of 7.66 mGy may be sufficient for the identification of temporal bone structures.

Introduction: One of the transitional zones of the human body is situated in the cervix uteri. The developmental differentiation of epithelial and stromal characteristics in such a region is of high clinical interest. However, few studies have focused on the development of this region, and information in anatomical and clinical textbooks is limited. We therefore examined the development of the human vaginal fornix and the cervix uteri during prenatal development., Materials and Methods: We examined 29 female embryos and fetuses between 20 and 34 weeks and two newborns using histology and immunohistochemistry., Results: The characteristic shape of the portiocervicis and the vaginal fornix first became visible in mid-term fetuses because of the different muscular coats and of an uncategorized Müllerian-derived epithelium, which was rapidly replaced by a multilayered squamous epithelium. Only thereafter, in older fetuses, were there organogenetic differentiation of the epithelia and the underlying stroma of the cervical canal. UGS-derived p63/CK17-positive cells could be identified as precursor cells for the squamous epithelium, and Müllerian-derived CK7-positive cells for the columnar-type epithelium. Both cell types and different stromal zones were already present in a prenatal transformation zone. Initial functional differentiation could be observed in perinatal stages., Conclusions: Our results on prenatal human development strongly support the view that two different cell lineages meet at the transitional zone of the cervix uteri and that these lineages depend on alternative signals from the underlying stromal compartment., (© 2021 The Authors. Clinical Anatomy published by Wiley Periodicals LLC on behalf of American Association of Clinical Anatomists.)

Background: During primary and revision total hip arthroplasty (THA) lesions of the superior gluteal nerve (SGN) can substantially compromise patient outcome. For the primary direct anterior approach (DAA) and its proximal approach extensions, especially the muscular branch entering the tensor fasciae latae (TFL) muscle is at risk. SGN lesions can result in fatty atrophy and functional loss of the TFL. Therefore, the course and branching pattern of the SGN were examined and related to the DAA and its proximal approach extension. The aim of the study is to describe safe and danger zones for the SGN with regard to the DAA and its proximal extensions., Methods: Twenty-five formalin-fixed cadavers with 48 hemipelves were dissected. The course, distribution, and branching pattern of the SGN and its muscular branch inserting into the TFL muscle were investigated with regard to the DAA with the help of anatomical landmarks like the greater trochanter and the iliac tubercle., Results: In 72.9% of the specimens the SGN passed the greater sciatic foramen superior to the piriformis muscle with one main trunk. The muscular branch of the SGN supplying the TFL divided from the main branch in 89.6% of the specimens at the level of the greater sciatic foramen. Before entering the TFL muscle the muscular branch showed a variable branching pattern in the interval between the gluteus medius and minimus. A danger zone for the SGN with regard to the DAA was found in the proximal fourth of the skin incision., Conclusion: Special care in proximal instrument placement should be taken during the DAA. When extending the DAA proximally manipulations in the proximal, caudal surgical window should be performed with the utmost care., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Although the direct anterior approach (DAA) has become a standard for primary and revision total hip arthroplasty, it involves a high risk of injuring the lateral femoral cutaneous nerve (LFCN). The aim of this study is to examine the course of the LFCN in relation to various skin incisions and approach extensions used for the DAA., Methods: We obtained 44 limbs and hemipelves from 22 formalin-preserved cadavers, in which LFCN was identified. All nerve branches of the LFCN were carefully traced. The branching pattern and the distribution in the thigh were described in relation to the standard approach for primary total hip arthroplasty, the skin crease bikini incision, the longitudinal extension, and the lazy S extension of the DAA., Results: We found 31 (70.5%) Sartorius-type, 6 (13.6%) posterior-type, and 7 (15.9%) fan-type branching patterns of the LFCN. We observed 2.02 branches per hemipelvis. All fan-type LFCNs had 3 or more than 3 branches. We found that the main branch of the LFCN was medial to the primary DAA approach as well as to the lazy S extended DAA approach. The bikini incision and the incision for the longitudinal extension of the DAA crosses the main branch of the LFCN in 100% of cases., Conclusion: The fan-type pattern of the LFCN might be harmed by all skin incisions. Chances are high that LFCN branches could be jeopardized with a bikini-type incision and the longitudinal extension of the DAA. The risk of jeopardizing the LFCN with a lazy S-type distal extension is reduced., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: This study investigates the accuracy of abutment transfer with current impression materials and provides a concise overview, including other relevant factors, in order to enable clinicians to make an informed decision about the optimal impression for this treatment procedure., Methods: In all, 96 impressions of a cadaver head with two orthodontic miniscrews in place were taken with four common impression materials by two observers and using two methods of application. After pouring with a standard type IV stone and abutment transfer, all models and the upper jaw (which had been separated from the head) were scanned in a standard model scanner (Zirkonzahn® [Zirkohnzahn GmbH, Gais, Italy] S600 ARTI) and evaluated using a computer-aided design (CAD) program (GOM-Inspect [Gesellschaft für optische Messtechnik m.b.H., Braunschweig, Germany]). The deviations were measured at six points per screw and statistically evaluated with SPSS® (IBM, Chicago, IL, USA)., Results: Optimal values were obtained with biphasic polyvinylsiloxane, while monophasic polyvinylsiloxane, alginate and polyether also resulted in acceptable accuracy. Observer experience showed no effect and the method of application had only a minor effect on accuracy., Conclusions: Within the limitations of this study, it seems that all impression materials are suitable for miniscrew abutment transfer, provided that methods of intraoral adaptation of the orthodontic appliance can be employed. If higher accuracy is needed or for clinicians with less experienced, a biphasic polyvinylsiloxane impression with the putty-wash technique should be used as this combination reduces setting time. The most cost-effective version, alginate, can be used if the consequences of greater deviations can be handled. Caution is advised with polyether if undercuts are present.

Purpose: The aim of this study was to assess the biomechanical properties of intact vertebra augmented using a local osteo-enhancement procedure to inject a triphasic calcium sulfate/calcium phosphate implant material., Methods: Twenty-one fresh frozen human cadaver vertebra (Th11-L2) were randomized into three groups: treatment, sham, and control (n = 7 each). Treatment included vertebral body access, saline lavage to displace soft tissue and marrow elements, and injection of the implant material to fill approximately 20% of the vertebral body by volume. The sham group included all treatment steps, but without injection of the implant material. The control group consisted of untreated intact osteoporotic vertebra. Load at failure and displacement at failure for each of the three groups were measured in axial compression loading., Results: The mean failure load of treated vertebra (4118 N) was significantly higher than either control (2841 N) or sham (2186 N) vertebra (p < 0.05 for: treatment vs. control, treatment vs. sham). Treated vertebra (1.11 mm) showed a significantly higher mean displacement at failure than sham vertebra (0.80 mm) (p < 0.05 for: treatment vs. sham). In the control group, the mean displacement at failure was 0.99 mm., Conclusions: This biomechanical study shows that a local osteo-enhancement procedure using a triphasic implant material significantly increases the load at failure and displacement at failure in cadaveric osteoporotic vertebra.

Objective: The objective was to identify the lowest doses required to detect and measure the position of the inferior alveolar canal (IAC) on multidetector computed tomography (MDCT) images using filtered backprojection (FBP) and sinogram-affirmed iterative reconstructions (SAFIRE) 3 and SAFIRE 5., Study Design: Four cadaveric mandibles were imaged using a reference protocol with standard dose and FBP and 3 ultra-low-dose protocols (LD1-LD3), using an MDCT scanner. All test examinations were reconstructed with FBP, SAFIRE 3, and SAFIRE 5. Subjective visibility of the IAC in the images and digital measurements of the height of the ridge above the IAC were recorded from test images and compared with those from the reference image using one-sample t tests, Bland-Altman plots, and linear regression., Results: Subjective visibility comparable to the standard protocol was obtained with an 84.6% dose reduction using the LD2 protocol. No statistically significant difference was found between the height measurements from the reference protocol and any of the LD1 and LD2 protocols. The t tests indicated a significant difference between the measurements from the reference and all LD3 test protocols. SAFIRE did not have an advantage over FBP images., Conclusions: Significant dose reduction from the reference dose can allow adequate detection and measurements of the IAC., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Bone ageing is governed by the linked activities of short-lived osteoblasts and osteoclasts in conjunction with long-lived osteocytes present in osseous structure. Besides their maintenance function, osteogenic cells also gain specific positional information, which may potentially trigger ageing-associated cellular deviations in terminally differentiated osteocytes differently in cranial versus postcranial tissues., Methods: We therefore investigated bone taken from deceased aged humans explanted at five distinct anatomical positions throughout the body and assessed physical and biological determinants applying radiologic and histologic measures., Results: We were able to show that significantly more osteocytes reside in aged cortical bone at cranial positions than within axial or limb skeleton. These cellular states and conditions were not found in the corresponding trabecular bone, where osteocyte numbers remain also high at postcranial positions. Parallel comparative analyses of bone microstructure as analyzed by means of computer tomography showed no significant differences., Conclusions: Considering differences and commonalities regarding the bone samples, such as loading, mechanisms of ossification or the surrounding stromal cell compartment, our findings indicate that positional information laid down during ontogenetic processes is instructive during the entire life thus potentially also moulding spatial-specific mechanistic distinctions of bone ageing., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Background: The aim of the current biomechanical study was to investigate a newly developed surgical technique for mallet fingers. The new method is based on the Ishiguro method which requires a K-wire through the distal interphalangeal joint for temporary fixation. The new technique avoids the joint trans fixation using a specially designed finger nail holder. This method was compared to the established Ishiguro's technique., Methods: For biomechanical testing, 32 paired, fresh-frozen human fingers (Digit II-V) of 4 donors (ages 60 to 71 years) were used. The paired fingers were assigned to either the new method or Ishiguro's technique. The biomechanical testing consisted of a cyclic cantilever bending (2000 cycles, 1-7N) followed by a load to failure test. The groups were evaluated for plastic deformation, stiffness, change in stiffness during cyclic loading, subluxation and failure load by analysing force-deflect data and fluoroscopic images., Findings: The nail fixation group showed significantly higher failure loads and stiffness than the trans fixation group. The values of plastic deformation were significantly lower in the nail fixation group. No differences were found in the change of stiffness. No subluxation was found in both groups., Interpretation: In the current biomechanical study, nail fixation performed at least as good as Ishiguro's trans fixation technique. The results and ease of implementation indicate that the newly developed nail fixation technique might be a useful treatment method in daily clinical practice without the need of temporary joint trans-fixation avoiding possible associated problems. To establish this method, clinical trials will be necessary., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: To assess the linear measurements of edentulous ridges recorded from multidetector row computed tomography (MDCT) images obtained by a previously untested ultra-low dose in combination with filtered back-projection (FBP), adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR)., Methods: Three cadavers were imaged using a reference protocol with a standard dose and FBP (volume CT dose index (CTDIvol): 29.4 mGy) and two ultra-low-dose protocols, LD1 and LD2 (CTDIvol: 0.53 and 0.29 mGy). All test examinations were reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. Linear measurements from the images of the edentulous ridges recorded from the test protocols were compared with those from the reference using a one-sample t test, Bland-Altman plots, and linear regression. Statistical significance was set at a p value of 0.05., Results: The one-sample t test demonstrated a statistically significant difference between the measurements from the reference protocol and all test protocols. The difference was not clinically significant for the following three test protocols: LD1/FBP, LD1/ASIR 50, and LD2/FBP. Bland-Altman plots with linear regression showed no systematic variation between the measurements obtained with the reference protocol and these three test protocols., Conclusions: The lowest-dose protocol to demonstrate comparable measurements with a standard MDCT dose was CTDIvol 0.29 mGy with FBP. These results must be considered with caution for areas of the jaws with thin cortication. The results in areas of thin cortication should be verified by studies with larger sample sizes at such areas and comparison with true gold standard measurements.

Objectives: To compare subjective and objective localization of the inferior alveolar canal (IAC) on multidetector CT (MDCT) images obtained by ultralow doses in combination with the reconstruction techniques of filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASIR), or model-based iterative reconstruction (MBIR) as compared to standard dose MDCT and FBP., Methods: Three cadavers were imaged with a reference standard dose MDCT examination (volume CT dose index: 29.4 mGy) reconstructed with FBP and 5 low dose protocols (LD1-5) (volumeCT dose index: 4.19, 2.64, 0.99, 0.53, 0.29 mGy) reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. Linear measurements from the crest of the ridge to the roof of the IAC were recorded. The results from the test protocols were compared with those from the reference using Bland-Altman plots., Results: Only three test protocols allowed the identification of the position of the IAC on all the sample sites: LD1/FBP and LD1/ASIR 100 and LD2/FBP. All three protocols allowed identification of the IAC with comparable results to the reference dose protocol; the 95% confidence interval limits for the measurement differences were ± 0.41 mm, but the differences were not statistically significant. The calculated effective dose for the LD2 protocol, for a scan length of 5 cm, was 27.7 µSv., Conclusions: Using FBP, comparable IAC measurements were achieved with 91% reduction in dose compared with a standard exposure protocol. The use of ASIR and MBIR did not improve identification of the IAC in MDCT low dose images.

Purpose: To compare the surface of computer-aided design (CAD) models of the maxilla produced using ultra-low MDCT doses combined with filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) reconstruction techniques with that produced from a standard dose/FBP protocol., Methods: A cadaveric completely edentulous maxilla was imaged using a standard dose protocol (CTDIvol: 29.4 mGy) and FBP, in addition to 5 low dose test protocols (LD1-5) (CTDIvol: 4.19, 2.64, 0.99, 0.53, and 0.29 mGy) reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. A CAD model from each test protocol was superimposed onto the reference model using the 'Best Fit Alignment' function. Differences between the test and reference models were analyzed as maximum and mean deviations, and root-mean-square of the deviations, and color-coded models were obtained which demonstrated the location, magnitude and direction of the deviations., Results: Based upon the magnitude, size, and distribution of areas of deviations, CAD models from the following protocols were comparable to the reference model: FBP/LD1; ASIR 50/LD1 and LD2; ASIR 100/LD1, LD2, and LD3; MBIR/LD1. The following protocols demonstrated deviations mostly between 1-2 mm or under 1 mm but over large areas, and so their effect on surgical guide accuracy is questionable: FBP/LD2; MBIR/LD2, LD3, LD4, and LD5. The following protocols demonstrated large deviations over large areas and therefore were not comparable to the reference model: FBP/LD3, LD4, and LD5; ASIR 50/LD3, LD4, and LD5; ASIR 100/LD4, and LD5., Conclusions: When MDCT is used for CAD models of the jaws, dose reductions of 86% may be possible with FBP, 91% with ASIR 50, and 97% with ASIR 100. Analysis of the stability and accuracy of CAD/CAM surgical guides as directly related to the jaws is needed to confirm the results.

Purpose: To investigate whether ultra-low-dose multidetector computed tomography (MDCT) combined with the reconstruction techniques filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASIR), or model-based iterative reconstruction (MBIR) alters the subjective classification of revised Lekholm and Zarb (LZ) bone types at prospective dental implant sites., Materials and Methods: Three cadavers underwent a reference MDCT examination using a standard dose volume (CT dose index [CTDI vol ]: 29.4 mGy) and reconstructed with FBP in addition to five test protocols (LD1-LD5) using ultra-low doses (CTDI vol : 4.19, 2.64, 0.99, 0.53, and 0.29 mGy, respectively) and reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. Transverse cross-sectional images of the jawbones were obtained, and three examiners subjectively classified the bone type in each image using the revised LZ classification. The bone type classifications obtained using the reference examination were compared with those obtained from the test protocols for each examiner, and kappa statistic was used to analyze the level of agreement between the reference and test protocols. The clinical significance of the differences was analyzed with Wilcoxon signed rank test., Results: Examiners 1 and 2 found moderate to strong agreement between the reference and test protocols, while Examiner 3 found strong to almost perfect agreement (P < .001). The Wilcoxon signed rank test did not demonstrate a clinical significance of the differences between the reference and test protocols for any of the three examiners., Conclusion: MDCT dose reductions of up to 99% did not significantly alter the subjective classification of bone at dental implant sites.

Introduction: Gluteal insufficiency is of concern with lateral approaches to total hip arthroplasty. Damage to the branches of the superior gluteal nerve may cause degeneration of the innervated muscles. The direct anterior approach exploits the intermuscular and internerval interval between tensor fasciae latae laterally and sartorius and rectus femoris muscle medially. In this study, the distance of the superior gluteal nerve in relation to anatomical landmarks was determined., Materials and Methods: Two experienced surgeons implanted trial components in 15 alcohol glycerol fixed cadavers with 30 hips. The trials were removed, and the main branch of the superior gluteal nerve and muscular branches of the nerve were exposed from lateral., Results: No visual damage to the main nerve branches and the location of the nerve in relation to the greater trochanter were noted by an experienced surgeon. The superior gluteal nerve and its muscular branches crossed the muscular interval between the gluteus medius and tensor fasciae latae muscles at a mean distance of 39 mm from the tip of the greater trochanter., Conclusions: The direct anterior approach for total hip arthroplasty minimizes the risk of injuring the superior gluteal nerve, which may result in a gluteal insufficiency. Special care should be paid on avoiding overstretching the tensor fasciae latea muscle using minimum force on retractors during surgery and by taking care of the entrance point of the superior gluteal nerve to the tensor fasciae latae.

Introduction: Surgical approaches through smaller incisions reveal less of the underlying anatomy, and therefore, detailed knowledge of the local anatomy and its variations is important in minimally invasive surgery. The aim of this study was to determine the location, extension, and histomorphology of the deep layer of the iliotibial band during minimally invasive hip surgery using the direct anterior approach (DAA)., Materials and Methods: The morphology of the iliotibial tract was determined in this cadaver study on 40 hips with reference to the anterior superior iliac spine and the tibia. The deep layer of the tractus iliotibialis was exposed up to the hip-joint capsule and length and width measurements taken. Sections of the profound iliotibial tract were removed from the hips and the thickness of the sections was determined microscopically after staining., Results: The superficial tractus iliotibialis had a length of 50.1 (SD 3.8) cm, while tensor fasciae latae total length was 18 (SD 2) cm [unattached 15 (SD 2.5) cm]. Length and width of the deep layer of the tractus iliotibialis were 10.4 (SD 1.3) × 3.3 (SD 0.6) cm. The deep iliotibial band always extended from the distal part of the tensor fascia latae (TFL) muscle to the lateral part of the hip capsule (mean maximum thickness 584 μm). Tractus iliotibialis deep layer morphology did not correlate to other measurements taken (body length, thigh length, and TFL length)., Conclusions: The length of the deep layer is dependent on the TFL, since the profound part of the iliotibial band reaches from the TFL to the hip-joint capsule. The deep layer covers the hip-joint capsule, rectus, and lateral vastus muscles in the DAA interval. To access the precapsular fat pad and the hip-joint capsule, the deep layer has to be split in all approaches that use the direct anterior interval.

Objectives: Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR., Methods: Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures., Results: Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel)., Conclusions: Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used., Key Points: • Ultra-low-dose MDCT protocols allowed more than 90 % reductions in dose. • Decreasing the dose generally increased density and noise. • Effect of IRT on density and noise varies with reconstruction kernel. • Accuracy of low-dose protocols for interpretation of bony anatomy not known. • Effect of low doses on accuracy of computer-aided design models unknown.

Aims: The aim was to develop a new laparoscopic technique for placement of a pudendal lead., Methods: Development of a direct, feasible and reliable minimal-invasive laparoscopic approach to the pudendal nerve (PN). Thirty-one embalmed human specimens were dissected for the relevant anatomic structures of the pelvis. Step-by-step documentation and analysis of the laparoscopic approach in order to locate the PN directly in its course around the medial part of the sacrospinous ligament and test this approach for feasibility. Landmarks for intraoperative navigation towards the PN as well as the possible position of an lead were selected and demonstrated., Results: The visible medial umbilical fold, the intrapelvine part of the internal pudendal artery, the coccygeus muscle and the sacrospinous ligament are the main landmarks. The PN traverses the medial part of the sacrospinous ligament dorsally, medially to the internal pudendal artery. The medial part of the sacrospinous ligament has to be exposed in order to display the nerve. An lead can be placed ventrally on the nerve or around it, depending on the lead type or shape., Conclusions: A precise and reliable identification of the PN by means of laparoscopy is feasible with an easy four-step approach: (1) identification of the medial umbilical fold; (2) identification of the internal iliac artery; (3) identification of the internal pudendal artery and incision of the coccygeus muscle ('white line', arcuated line); and (4) exposition of the medial part of the sacrospinous ligament to display the PN., (© 2016 The Authors. Neurourology and Urodynamics Published by Wiley Periodicals, Inc.)