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Zusammenfassung. Im klinischen Alltag sind wir sehr häufig mit Bursitiden konfrontiert. Sie können in praktisch jeder Gelenksregion z.B. bei lokalen mechanischen Überlastungen oder nach einem Trauma oder im Rahmen einer entzündlichen Systemerkrankung auftreten. In dieser Übersichtsarbeit fokussieren wir auf die Bursen im Bereich der Schulter und möchten einen Beitrag leisten, um vom «Mythos Bursitis subacromialis» wegzukommen.

The sacroiliac auricular surface is morphologically variable. The impact of morphology variations on subchondral mineralization distribution has not been investigated. Sixty-nine subject datasets were subjected to CT-osteoabsorptiometry for chronic loading visualization. Auricular surface morphologies were sorted into three types based on posterior angle size: >160°, 130-160° and 2, with higher values in males. Sacral and iliac areas were significantly different between sexes. Type 2 was the most common (75%) and type 3 the least common morphology (9%). M1 was the most common pattern (62% of surfaces) by sex (males 60%, females 64%) with the anterior border as the maxima region in all three morphologies. Sacra have a majority of surfaces with patterns from the marginal group (98%). Ilia have mineralization concentrated at the anterior border (patterns M1+N2=83%). Load distribution differences related to morphological diversity seems to have little effect on stress-related bone adaptation visualized with CT-osteoabsorptiometry. Higher iliac side mineralization was observed in larger joints potentially related to cartilage distribution. Chronic loading adaptation might account for age-related morpho-mechanical size alterations in males.

BACKGROUND AND AIMS Conserved specimens do not decay and therefore permit long-term experiments thereby overcoming limited access to fresh (frozen) temporal bones for studies on middle ear mechanics. We used a Thiel conservation method which is mainly based on a watery solution of salts. In contrast to pure Formalin, Thiel conservation aims to preserve the mechanical proprieties of human tissue. The aim of this study is to examine the effect of Thiel conservation on bone conduction in the same specimen before and after conservation. METHODS Nine ears of five defrosted whole heads were stimulated with a direct, electrically driven, bone anchored hearing system (Baha, Baha SuperPower). The motion produced by bone conduction stimulation was measured with a single point laser Doppler vibrometer (LDV) at the promontory, the ossicular chain, and the round window through a posterior tympanotomy. After the initial experiments, the entire whole heads were placed in Thiel solution. In order to enable direct comparison between fresh frozen and Thiel specimens, our Thiel conservation did not include intravascular and intrathecal perfusion. The measurements were repeated 3 and 12 months later. To determine the effect of freezing, defrosting, and embalming on the whole heads, CT scans were performed at different stages of the experimental procedure. Additionally, three extracted temporal bones were stimulated a Baha, motion of the promontory measured by LDV and embalmed in Thiel solution to investigate the direct impact of Thiel solution on the bone. RESULTS The averaged magnitude of motion on the promontory increased in whole head specimens by a mean of 10.3 dB after 3 months of Thiel embalming and stayed stable after 12 months. A similar effect was observed for motion at the tympanic membrane (+7.2 dB), the stapes (+9.5 dB), and the round window (+4.0 dB). In contrast to the whole head specimens, the motion of the extracted temporal bones did not change after 3 months of Thiel embalming (-0.04 dB in average). CT scans of the whole heads after conservation showed a notable brain volume loss mostly >50% as well as a remarkable change in the consistency and structure of the brain. Partial changes could already be observed before the Thiel embalming but after 1-2 days of defrosting. In an additional experiment, a substitution of brain mass and weight by Thiel fluid did not lead to new deterioration in sound transmission. In contrast, a frozen (non-defrosted) whole head showed a distinctively reduced magnitude of promontory motion before defrosting. DISCUSSION For our setup, the vibration of the ear due to bone conduction in the same whole head specimens significantly increased after Thiel conservation. Such an increase was not observed in extracted temporal bone specimens. Due to brain changes in the CT scans, we investigated the consequences of the brain volume changes and structure loss on the frozen brain before defrosting. The loss of brain volume alone could not explain the increase of ear vibrations, as we did not observe a difference when the volume was replaced with Thiel fluid. However, freezing and defrosting of the entire brain seems to have a major influence. Beside the destructive effect of freezing on the brain, the modified conservation method without perfusion changed the brain structure. In conclusion, bone conduction in whole heads depends on the physical condition of the brain, rather than on the conservation.

CME-Sonography 106: Subacromial Bursa - A Myth

Objective: Developing robotic tools that introduce substantial changes in the surgical workflow is challenging because quantitative requirements are missing. Experiments on cadavers can provide valuable information to derive workspace requirements, tool size, and surgical workflow. This work aimed to quantify the volume inside the knee joint available for manipulation of minimally invasive robotic surgical tools. In particular, we aim to develop a novel procedure for minimally invasive unicompartmental knee arthroplasty (UKA) using a robotic laser-cutting tool. Methods: Contrast solution was injected into nine cadaveric knees and computed tomography scans were performed to evaluate the tool manipulation volume inside the knee joints. The volume and distribution of the contrast solution inside the knee joints were analyzed with respect to the femur, tibia, and the anatomical locations that need to be reached by a laser-cutting tool to perform bone resection for a standard UKA implant. Results: Quantitative information was determined about the tool manipulation volume inside these nine knee joints and its distribution around the cutting lines required for a standard implant. Conclusion: Based on the volume distribution, we could suggest a possible workflow for minimally invasive UKA, which provides a large manipulation volume, and deducted that for the proposed workflow, an instrument with a thickness of 5-8 mm should be feasible. Significance: We present quantitative information on the three-dimensional distribution of the maximally available volume inside the knee joint. Such quantitative information lays the basis for developing surgical tools that introduce substantial changes in the surgical workflow.

The successful integration of orthopedic implants can rely on site-specific placement. In this study, we determined compartment-specific trabecular architecture in the cervical vertebra. We examined the micro-computed tomography scans of seven prospectively healthy C4 vertebrae, evaluated their microstructure parameters (bone volume fraction (BV/TV), bone surface density (BS/BV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number per volume(Tb.N), connectivity density (Conn.D), structure model index (SMI), and degree of anisotropy (DA)., and compared the trabecular architecture in twelve predefined volumes of interest (VOI); the cranial and caudal 0–10%, 10–15%, and 25–50% in both the ventral and dorsal half. Tb.Sp and Tb.N were the only two parameters that displayed significant differences in averaged values of VOI. Nonetheless, distinct, consistent ventral-dorsal modulations were seen in matched sample ventral-dorsal comparison in the BV/TV, BS/BV, and SMI overall levels, as well as in Tb.Th in the three caudal levels. In a simplification the vertebra was split into ventral-cranial, dorsal-cranial, ventral-caudal, and dorsal-caudal equal quarters. The ventral quarters display higher BV/TV, respectively lower BS/BV and SMI than their sample paired dorsal quarters. The ventral-cranial quarter shows the lowest BV/TV and the highest BS/BV and SMI, describing spacious cancellous bone with rod-like trabeculae. In contrast, the dorsal-caudal quarter exhibits the highest BV/TV and Tb.Th and the lowest BS/BV and SMI, illustrating thicker, denser, and more plate-like trabecula. The dorsal-cranial and ventral-caudal quarters are comparable and represent intermediate characteristics. The dorsal quadrants are "stronger" than their ventral counterparts and caudal quarters are "stronger" than their adjacent cranial segments. This suggests that the strongest part is the caudal dorsal part, and the weakest is the cranial ventral one.

Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain. Mineralization patterns of the sacroiliac (SIJ) subchondral bone plate (SCB) may reflect long-term adaptations to the loading of the joint. Mineralization densitograms of 27 SIJD patients and 39 controls, were obtained using CT osteoabsorptiometry. Hounsfield unit (HU) values of the SCB mineralization of superior, anterior and inferior regions on the iliac and sacral auricular surfaces were derived and statistically compared between SIJD-affected and control cohorts. Healthy controls showed higher HU values in the iliac; 868 ± 211 (superior), 825 ± 121 (anterior), 509 ± 114 (inferior), than in the sacral side; 541 ± 136 (superior), 618 ± 159 (anterior), 447 ± 91 (inferior), of all regions (p

Background: The subchondral lamella of the sacroiliac joint (SIJ) auricular surface is morphologically inconsistent, varying inter-individually and side-dependently. These variations have been well documented, however, the morpho-mechanical relationship to sacroiliac joint dysfunction (SIJD) remains unstudied to date. Here, the bone mineralisation density of the iliac and sacral auricular surface subchondral endplate is compared between morphological subtypes, as well as in large and small surfaces, in a cohort comprising SIJD joints and controls.Methods: Computed tomography (CT) datasets from 29 patients with bilateral or unilateral SIJD were subjected to CT osteoabsorptiometry. Sacral and iliac surface areas and posterior angles were calculated and surfaces were classified into small (3) and large (≥15 cm3) joints and morphological types 1 (>160°), 2 (130-160°) and 3 (Results: The surface area of all joints in the cohort averaged 15.0±2.4 cm2 (males 16.2±2.5 cm2, females 13.7±1.6 cm2). No age correlations with surface area were found nor differences in mean HU values when comparing sizes, sexes or morphology type when looking at painful joints (unilateral or bilateral) and contralateral non-painful joints. Comparisons of controls with the SIJD cohort revealed significant differences in female sacra (p=0.02) and small sacra (p=0.03). There was low conformity in marginal and non-marginal patterns, 26% for contralateral non-painful joints, and 46% conformity in painful joints. The majority of dysfunctional joints was of type 2 morphology (59%), equally distributed between small (49%) and large joints (51%). Larger joints had the highest frequency of painful joints (72%). Regarding the prominence of sub-patterns, M1C was more prominent in painful joints. Conclusions: Load distribution related to difference in auricular surface morphology seems to have little impact on pain-related subchondral bone adaptation in cases of SIJD. Larger joints may be predisposed to the onset of pain due to the weakening of the extracapsular structures. Pain-affected joints reflect common conformity patterns of sacral apex mineralisation with corresponding superior corner iliac mineralisation.

Traditional bone surgery using saws and chisels is associated with direct contact of instruments with the bone causing friction, heat and pressure and hence, damaging the bone and the surrounding soft tissues.Cold ablation laser osteotomy offers new possibilities to perform corrective osteotomies in the field of bone surgery. We introduce the technology of navigated cold ablation robot-guided laser osteotomy, present potential applications, and preliminary pre-clinical cadaver test results in the field of hand-, wrist- and forearm surgery.The cadaver tests showed first promising results for corrections in all planes and axes using different cutting patterns.Cold ablation laser osteotomy seems to be a feasible new method to perform osteotomies in the field of hand-, wrist- and forearm surgery. Primary osseous stability could be achieved using various cutting patterns which could lead to reduction of the amount of hardware required for osteosynthesis. Further tests are required to proof the latter and precision.

Degenerative or traumatic ruptures of the distal biceps tendon are less common than proximal lesions. Distal lesions lead to a significant loss of function with usually considerable discomfort for patients. Therefore, precise diagnostics using operator-dependent high-resolution musculoskeletal ultrasound with illustration of the extent of the affected tendon lesion are important for optimizing patient management. In this article, we discuss the precise high-resolution musculoskeletal ultrasound and sonoanatomy of the distal biceps tendon and emphasize its importance for the surgical treatment of tendon lesions. In this review and pictorial essay, we first focus on the description of the precise anatomy and ultrasound anatomy of this clinically important region. Furthermore, we highlight different ultrasound scanning techniques for the correct assessment of the distal biceps tendon. Various approaches for optimal sonographic assessment of the distal biceps tendon have been suggested in the literature: the anterior approach, the lateral access, the medial access and the posterior approach. In the second part of the article, we focus on the evaluation of surgical repair techniques of distal biceps tendon lesions considering the extent of the rupture zone of the distal biceps tendon based on the ultrasound findings. Surgical techniques are explained from the orthopedic surgical point of view. Degenerative or traumatic ruptures of the distal biceps tendon are less common than proximal lesions. Distal lesions lead to a significant loss of function with usually considerable discomfort for patients. Therefore, precise diagnostics using operator-dependent high-resolution musculoskeletal ultrasound with illustration of the extent of the affected tendon lesion are important for optimizing patient management. In this article, we discuss the precise high-resolution musculoskeletal ultrasound and sonoanatomy of the distal biceps tendon and emphasize its importance for the surgical treatment of tendon lesions. In this review and pictorial essay, we first focus on the description of the precise anatomy and ultrasound anatomy of this clinically important region. Furthermore, we highlight different ultrasound scanning techniques for the correct assessment of the distal biceps tendon. Various approaches for optimal sonographic assessment of the distal biceps tendon have been suggested in the literature: the anterior approach, the lateral access, the medial access and the posterior approach. In the second part of the article, we focus on the evaluation of surgical repair techniques of distal biceps tendon lesions considering the extent of the rupture zone of the distal biceps tendon based on the ultrasound findings. Surgical techniques are explained from the orthopedic surgical point of view.

BACKGROUND To investigate the impact of scanning parameter in cone-beam computed tomography (CBCT) images on accuracy and confidence with measurements of furcation involvement (FI) in maxillary molars. MATERIAL AND METHODS Six half cadaver heads with present maxillary molars (n = 10) were available. CBCT scans with the fixed-parameter field of view (4 × 4 cm, 12 × 17 cm) amperage and voltage (4 mA, 90 kV) and with varying scan modes (SM), that is images/scan (IS), voxel sizes (VZ) and rotation (R), were performed using one CBCT apparatus. The images were analysed by two calibrated investigators. Horizontal FI's were measured in mm or a "through and through" destruction (FI degree III) was recorded. Each rater scored the FI measurements performed in each scan as "confident" or as "not confident". Data were statistically analysed using chi-square tests. RESULTS The agreement between CBCT FI measurements and intra-surgical FI measurements varied according to SM (SM HiSp 180°, 0.08: kappa 0.538, CI; 95%: 0.362-0.714; SM Std. 360°, 0.25: kappa 0.698, CI; 95%: 0.534-0.861). The number of measurements scored as "confident" varied according to SM (SM Std. 360°, 0.08:52 out of 60 measurements; SM Std. 360°, 0.25:16 out of 60 measurements; p

Background For optimal prosthetic anchoring in omarthritis surgery, a differentiated knowledge on the mineralisation distribution of the glenoid is important. However, database on the mineralisation of diseased joints and potential relations with glenoid angles is limited. Methods Shoulder specimens from ten female and nine male body donors with an average age of 81.5 years were investigated. Using 3D-CT-multiplanar reconstruction, glenoid inclination and retroversion angles were measured, and osteoarthritis signs graded. Computed Tomography-Osteoabsorptiometry (CT-OAM) is an established method to determine the subchondral bone plate mineralisation, which has been demonstrated to serve as marker for the long-term loading history of joints. Based on mineralisation distribution mappings of healthy shoulder specimens, physiological and different CT-OAM patterns were compared with glenoid angles. Results Osteoarthritis grades were 0-I in 52.6% of the 3D-CT-scans, grades II-III in 34.3%, and grade IV in 13.2%, with in females twice as frequently (45%) higher grades (III, IV) than in males (22%, III). The average inclination angle was 8.4°. In glenoids with inclination ≤10°, mineralisation was predominantly centrally distributed and tended to shift more cranially when the inclination raised to > 10°. The average retroversion angle was − 5.2°. A dorsally enhanced mineralisation distribution was found in glenoids with versions from − 15.9° to + 1.7°. A predominantly centrally distributed mineralisation was accompanied by a narrower range of retroversion angles between − 10° to − 0.4°. Conclusions This study is one of the first to combine CT-based analyses of glenoid angles and mineralisation distribution in an elderly population. The data set is limited to 19 individuals, however, indicates that superior inclination between 0° and 10°-15°, and dorsal version ranging between − 9° to − 3° may be predominantly associated with anterior and central mineralisation patterns previously classified as physiological for the shoulder joint. The current basic research findings may serve as basic data set for future studies addressing the glenoid geometry for treatment planning in omarthritis.

Introduction: Despite intensive research, current total knee arthroplasty (TKA) designs do not always provide the correct kinematics for the native joint and thus further optimisation is necessary. Several studies support the importance of malrotation of the tibial components in the failure of TKA. We hypothesise that using the anatomical tibial axis (ATA) to align tibial component rotation on the resected tibial surface may lead to an internal rotation error due to relative anterior shift of the lateral articular surface centre compared to the medial one. The aim of this study was to compare the anatomical tibial axis of the physiological tibial joint surface to the resected one. Method: Twenty formalin-fixed cadaveric knees were obtained for study. After computed tomography scanning the data of each specimen were entered into a standardised coordinate system and virtual bone cuts were performed with 6, 8 and 10mm resection depths. The positions of the articular surface centres were determined at each resection depth. Results: The lateral articular surface centre had moved anteriorly after the resection by a mean 1.475mm, while the medial one had not changed significantly. Resecting the tibia at a 6-mm cut and using the transverse tibial axis to align the prosthetic tibial plateau will result in a mean 4.0° (95% confidence interval, 2.5-5.5°) of internal rotation compared to the uncut tibia. Discussion: The ATA lies in 6 degrees of external rotation compared to the perpendicular to the posterior tibial condylar axis (PTCA). Graw et al. suggest aligning the tibial component in 10 degrees of external rotation to the latter. Thus, if we accept the above suggestion, the ATA is 4 degrees internally rotated compared to the same line on the resected proximal tibia. These prior studies appear to be in accordance with our findings. Conclusions: We conclude that using the ATA on the resected tibial surface may contribute to an internal rotation error.

Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain. Mineralization patterns of the sacroiliac (SIJ) subchondral bone plate (SCB) may reflect long-term adaptations to the loading of the joint. Mineralization densitograms of 27 SIJD patients and 39 controls, were obtained using CT osteoabsorptiometry. Hounsfield unit (HU) values of the SCB mineralization of superior, anterior and inferior regions on the iliac and sacral auricular surfaces were derived and statistically compared between SIJD-affected and control cohorts. Healthy controls showed higher HU values in the iliac; 868 ± 211 (superior), 825 ± 121 (anterior), 509 ± 114 (inferior), than in the sacral side; 541 ± 136 (superior), 618 ± 159 (anterior), 447 ± 91 (inferior), of all regions (p 0.01). This was similar in SIJD; ilium 908 ± 170 (superior), 799 ± 166 (anterior), 560 ± 135 (inferior), sacrum 518 ± 150 (superior), 667 ± 151 (anterior), 524 ± 94 (inferior). In SIJD, no significant HU differences were found when comparing inferior sacral and iliac regions. Furthermore, HU values in the inferior sacral region were significantly higher when compared to the same region of the healthy controls (524 ± 94 vs. 447 ± 91, p 0.01). Region mineralization correlated negatively with age (p 0.01). SIJD-affected joints reflect a high mineralization of the sacral inferior region, suggesting increased SIJD-related mechanical stresses. Age-related SCB demineralization is present in all individuals, regardless of dysfunction.

Purpose: To quantify the effects of the systematic internal and external femoral component rotations and tibial slope on the medial and lateral tibiofemoral gaps in total knee endoprostheses. Methods: Nineteen knee cadaver specimens with an intact ligament apparatus were fixed in a custom frame, facilitating physiological flexion motion. Virtual total knee arthroplasty (TKA) was performed on three-dimensional models obtained from computed tomography ​scans (0° and 90° flexions) with systematically altered femur rotations and tibial slopes. Results: Both the femur rotation and the tibial slope influenced the medial and lateral tibiofemoral flexion gaps (p ​

Background: Preoperative planning of total knee arthroplasty is usually performed using knee-centred computed tomography (CT) data sets. The disadvantage of these data sets is having no account of the biomechanical axis of the lower extremity, known as Mikulicz line. It aligns the femoral head to the middle of the talocrural joint. For optimal prosthesis arrangement, the knee CT data set must therefore be brought in congruency with this line of loading to achieve the best results and eliminate rotational malalignments.This study aims to establish a relation between the knee-centred clinical coordinate system (CCS) and a biomechanical coordinate system (BCS) based on the Mikulicz line. Methods: CT data sets of 45 lower extremities were evaluated. Using VG Studio Max, a visualisation and measurement software program; each CT data set was aligned according to the CCS and BCS. After superimposing both the aligned data sets, the deviations of both coordinate systems in all three planes were measured with the centre of the knee defined as the origin. Results: For the coronal plane, the CCS was demonstrated to be 2.54° in adduction compared to the BCS [standard deviation (SD) = 1.8°]. In sagittal view, the CCS was demonstrated to be 0.3° retroversed (SD = 3.27°). Finally, the deviation in the axial plane showed an outward rotation of 3.39° (SD = 1.99°). The alignment as well as the measurements demonstrated high intraobserver and interobserver reproducibility. Conclusion: Both coordinate systems can be established in knee-centred CT data sets in a reproducible manner. Clearly, the CCS differs significantly from the BCS describing the biomechanical axis, but mathematical-based adaptations and corrections can be performed. The translational potential of this article: The findings of this study allow a mathematical conversion of a knee CT to the biomechanical axis of the leg. Keywords: Alignment, Computed tomography, Coordinate system, Mikulicz line, Total knee arthroplasty

Background: Sacroiliac joint arthrodesis is an ultima ratio treatment option for sacroiliac joint dysfunction. Fusion drastically reduces sacroiliac joint movement providing long-lasting pain-relief associated with tension-relief to the innervated sacroiliac joint structures involved in force closure. Objectives: To display the bone mineralization distribution patterns of the subchondral bone plate in 3 distinct regions (superior, anterior, and inferior) of the sacral and iliac counterparts of the sacroiliac joint pre- and post-sacroiliac joint arthrodesis and compare patterns of sacroiliac joint dysfunction postsacroiliac joint fusion with sacroiliac joint dysfunction pre- arthrodesis patterns and those from healthy controls. Study Design: An observational study. Setting: The research took place at the University of Basel, Switzerland, where the specific image analysis program (Analyze, v7.4, Biomedical Imaging Resources, Mayo Foundation, Rochester, NY, USA) was made available. Methods: Mineralization densitograms of 18 sacroiliac joint dysfunction patients pre- and post-sacroiliac joint arthrodesis (≥ 6, ≥ 12, and ≥ 24 months post-surgery) were obtained using computed tomography osteoabsorptiometry. For each patient, pre- vs. post-surgery statistical comparisons were undertaken, using the Hounsfield unit values derived from the subchondral mineralization of superior, anterior, and inferior regions on the iliac and sacral auricular surfaces. Post-operative values were also compared to those from a healthy control cohort (n = 39). Results: In the pre-operative cohort at all 3 follow-up times, the superior iliac region showed significantly higher Hounsfield unit values than the corresponding sacral region (P < 0.01). Mineralization comparisons were similar for the sacrum and ilium in the anterior and inferior regions at all follow-up points (P > 0.5) with no surgery-related changes. Sacral density increased significantly in the post-operative state; not observed on the ilium. Post-operative sacroiliac joints showed a significantly increased mineralization in the superior sacrum after ≥ 6 months (P < 0.05), not replicated after ≥ 12 nor ≥ 24 months. Further comparison of post-operative scans versus healthy controls revealed significantly increased mineralization in the superior sacral region at (≥) 6, 12, and 24 months (P < 0.01), likely related to bone grafting, and in the anterior and inferior regions in post-operative scans at ≥ 12 and ≥ 24 months follow-up (P < 0.05). Limitations: The given study is limited in sample size. Post-operative computed tomography scans had screws which may have left artifacts or partial volume effects on the surfaces. Healthy controls were different patients to the sacroiliac joint dysfunction and post-operative cohorts. Both cohorts were agematched but this comparison did not take into account potential population differences. Size differences in the regions may have also been an influencing factor of the results as the regions were based on the size and shape of the articular surface. Conclusions: Sacroiliac joint arthrodesis results in an increased morpho-mechanical conformity in the anterior and inferior sacrum and reflects variable morpho-mechanical density patterns compared to the healthy state due to permanent alterations in the kinematics of the posterior pelvis. Key words: Bone mineral density, bone mineralization, computed tomography, Hounsfield units, osteoabsorptiometry, sacroiliac, sacroiliac joint arthrodesis, sacroiliac joint fusion, sacroiliac joint dysfunction, subchondral bone plate

BACKGROUND AND AIMS As an alternative to fresh temporal bones, Thiel conserved specimens can be used in the study of ear mechanics. Conserved temporal bones do not decay, permit long-term experiments and overcome problems with limited access to fresh (frozen) temporal bones. Air conduction motion of the tympanic membrane (TM), stapes (ST) and round window (RW) in Thiel specimens is similar to that of fresh specimens according to reports in the literature. Our study compares this motion directly before and after conservation for the same specimens. METHODS The magnitude of motion of TM, ST and RW elicited by acoustic stimulation via the external auditory canal was measured using single point laser Doppler vibrometry (LDV) accessed through a posterior tympanotomy. For the initial measurements (10 ears), fresh frozen whole heads were thawed for at least 24��h. Afterwards, the entire whole heads were embalmed according to the Thiel embalming method and measurements were repeated 3 and 12 months later. RESULTS The magnitudes of TM, ST and RW motion before and after Thiel conservation differed maximally 10��dB on average. A significant increase in TM motion was observed at low frequencies only after long term conservation (12 months). ST motions decreased significantly between 161 and 5300��Hz after 3 months of Thiel conservation. Over the same time period RW motions decreased significantly between 100 and 161��Hz and 489-788��Hz. The ST and RW motions across all measured frequencies were lower after 3 months by 5.7��dB and 7.1��dB, respectively, without further changes after 12 months of conservation. The mean phase shift between ST and RW motion was only 2.1�� for frequencies below 450��Hz. DISCUSSION AND CONCLUSION Thiel embalming changes motion of TM after long term conservation. ST and RW motion changed mainly after short term conservation. The phase shifts close to 180�� between ST and RW motion indicates that the cochlea was still filled with liquid without air bubbles. The results show that Thiel conserved specimens can be used as an alternative model to fresh frozen preparations with some limitations when studying mechanics of the normal human ear, for example, in implant design.

Background Despite new 3-dimensional imaging modalities, 2-dimensional fluoroscopy remains the standard intraoperative imaging modality. The elbow has complex anatomy, and defined standard fluoroscopic projections are lacking. Therefore, the aim of this study was to define standard projections of the elbow for intraoperative fluoroscopy. Methods This study consisted of 2 parts. In part I, dissected cadaveric elbows were examined under fluoroscopy, and their radiographic anatomical features were assessed, with focus on projections showing defined anatomical landmarks. In part II, projections from part I were verified on entire cadavers to simulate intraoperative imaging. Standard projections for anteroposterior (AP) and lateral views as well as oblique and axial views were recorded. Results Eight standardized projections could be defined and included 3 AP, 1 lateral, 2 oblique, and 2 axial views. By applying these specific projections, we could visualize the epicondyles, the trochlea with its medial and lateral borders, the capitellum, the olecranon, the greater sigmoid notch, the coronoid process including its anteromedial facet, the proximal radioulnar joint with the radial tuberosity, and the anterior and posterior joint lines of the distal part of the humerus. These standard projections were reliably obtained using a specific sequence. Conclusions Knowledge about radiographic anatomy and standard projections is essential for visualizing important landmarks. With the presented standard projections of the elbow, important anatomical landmarks can be clearly examined. Thus, fluoroscopic visualization of anatomical fracture reduction and correct implant placement should be facilitated. Clinical relevance This basic science cadaveric study defines fluoroscopic standard projections of the elbow essential for visualization of anatomical landmarks during surgery.

CASE Post-traumatic defects of the metacarpophalangeal joint (MCPj) remain challenging for hand surgeons. Restoration of stability and motion are difficult to achieve because of the complex anatomy and kinematics. The Robert Mathys (RM) semiconstrained prosthesis offers good intrinsic stability and mobility and therefore seems suitable. We report on a patient where the RM prosthesis was used for a traumatic destroyed ring finger MCPj reconstruction but failed because of aseptic loosening. We discuss possible reasons in light of the current literature on post-traumatic MCPj arthroplasties and the RM prosthesis in particular. CONCLUSION The RM proximal interphalangeal prosthesis does not seem suitable for post-traumatic replacement of the MCPj.

This report describes activity in Europe for the years 2016 and 2017 in the area of cellular and tissue-engineered therapies, excluding hematopoietic stem cell treatments for the reconstitution of hematopoiesis. It is the eighth of its kind and is supported by five established scientific organizations. In 2016 and 2017, a combined 234 teams from 29 countries responded to the cellular and engineered tissue therapy survey; 227 teams reported treating 8236 patients in these 2 years. Indications were categorized in hematology/oncology (40%; predominantly prevention or treatment of graft vs. host disease and hematopoietic graft enhancement), musculoskeletal/rheumatological disorders (29%), cardiovascular disorders (6%), neurological disorders (4%), gastrointestinal disorders (

Segmentation of distinct bones plays a crucial role in diagnosis, planning, navigation, and the assessment of bone metastasis. It supplies semantic knowledge to visualisation tools for the planning of surgical interventions and the education of health professionals. Fully supervised segmentation of 3D data using Deep Learning methods has been extensively studied for many tasks but is usually restricted to distinguishing only a handful of classes. With 125 distinct bones, our case includes many more labels than typical 3D segmentation tasks. For this reason, the direct adaptation of most established methods is not possible. This paper discusses the intricacies of training a 3D segmentation network in a many-label setting and shows necessary modifications in network architecture, loss function, and data augmentation. As a result, we demonstrate the robustness of our method by automatically segmenting over one hundred distinct bones simultaneously in an end-to-end learnt fashion from a CT-scan.

Mitochondrial mutations and dysfunction have been demonstrated in several age-related disorders including osteoarthritis, yet its relative contribution to pathogenesis remains unknown. Here we evaluated whether premature aging caused by accumulation of mitochondrial DNA mutations in PolgD275A mice predisposes to the development of knee osteoarthritis. Compared with wild type animals, homozygous PolgD275A mice displayed a specific bone phenotype characterized by osteopenia of epiphyseal trabecular bone and subchondral cortical plate. Trabecular thickness was significantly associated with osteocyte apoptosis rates and osteoclasts numbers were increased in subchondral bone tissues. While chondrocyte apoptosis rates in articular and growth plate cartilage were similar between groups, homozygous mitochondrial DNA mutator mice displayed elevated numbers of hypertrophic chondrocytes in articular calcified cartilage. Low grade cartilage degeneration, predominantly loss of proteoglycans, was present in all genotypes and the development of osteoarthritis features was not found accelerated in premature aging. Somatically acquired mitochondrial DNA mutations predispose to elevated subchondral bone turnover and hypertrophy in calcified cartilage, yet additional mechanical or metabolic stimuli would seem required for induction and accelerated progression of aging-associated osteoarthritis.

The reasons leading to rotational tibial malalignment in total knee arthroplasties (TKAs) remain unclear. A previous cadaver study has shown an increase in internal rotation of the anatomical tibial axis (ATA) after the tibial cut. This study investigates the influence of tibial slope on the ATA and the size of the resected tibial surface.; CT scans of 20 cadaver knees were orientated in a standardized coordinate system and used to determine the position of the centres of rotation of the medial and lateral tibial articular surfaces and, hence, of the ATA, after a virtual resection of 6 mm with 0°, 3.5°, 7° and 10° slope, respectively. Furthermore, at each slope, the radii of the medial and lateral tibial articular surfaces after resection were calculated.; Compared to resection of 6 mm with 0° slope, a slope of 3.5° resulted in a mean external rotation of the ATA of 0.9° (SD, 1.5°; P = 0.025). A slope of 7° resulted in a mean external rotation of the ATA of 1.0° (SD 2.0°; P = 0.030) and a slope of 10° had no influence on the rotation of the ATA. The radii of the medial and lateral articular surfaces of the cut tibiae were larger than those of the uncut tibia (P < 0.001).; Differences in the posterior tibial slope should not contribute to a rotational malalignment when using the ATA to align the prosthetic tibial plateau. Although statistically significant, the change in ATA with increasing slope was negligible.

Tissue-nonspecific alkaline phosphatase (TNAP) is playing a key role in bone calcification, as has been demonstrated in different mammalian species including human and rodents. However, to investigate age-related changes during life history, histochemical demonstration of TNAP is severely hampered, particularly in the elderly, by technical difficulties associated with sectioning calcified tissue. Sufficient fixation must precede decalcification since poorly fixed bone tissue is exposed to the deleterious effects of decalcification reagents. In order to find a method that would allow cryosectioning of bone without loss of TNAP activity, we assessed the efficacy of different fixation reagents regarding the effects on structural integrity and TNAP activity using liver and osseous tissue from younger and older horses. The results of this study reveal that glyoxal-based fixatives sufficiently preserved bone tissue for successful cryosectioning without compromising TNAP activity. The method described combines the demonstration of TNAP activity with optimal preservation of tissue morphology in osseous tissue of younger and even of older mammals. As a model species, we selected horse bones in light of potentially higher similarities to ageing history and lifelong locomotion in humans as compared to other, mostly smaller, experimental model species with a much shorter life span and artificial locomotive activity when kept in cages. This may serve as a basis for future studies addressing the impact of different life traits in iconic, domestic and companion animals, which are often patients in veterinary medicine, as well as for basic research on human physiology and pathologies of the musculoskeletal system.

This study aimed at evaluating the potential of CT-calculometry (CT-CM) as a novel method to determine mineralisation, composition, homogeneity and volume of urinary calculi based on preoperative non-contrast-enhanced computed tomography (NCCT) scans. CT-CM was performed in preoperative NCCTs of 25 patients treated for upper tract urinary calculi by ureterorenoscopy or percutaneous nephrolithotomy. Absolute mineralisation values were achieved by use of quantitative CT-osteoabsorptiometry and compared to Fourier infrared spectroscopy as a reference for stone composition. Homogeneity was assessed by advanced software-based NCCT post-processing and visualised by using a maximum intensity projection algorithm. Volumetric measurement was performed by software-based three-dimensional reconstruction. CT-CM was feasible in all of the 25 NCCTs. Absolute mineralisation values calculated by quantitative CT-OAM might be used to identify the most frequent stone types. High levels of inhomogeneity could be detected even in pure component stones. Volumetric measurement could be performed with minimal effort. CT-CM is based on advanced NCCT post-processing software and represents a novel and promising approach to determine mineralisation, composition, homogeneity and volume of urinary calculi based on preoperative NCCT. CT-CM could provide valuable information to predict outcome of different stone treatment methods.

Purpose: The aim of this study was to investigate the distribution of density of the subchondral bone plate within the articular surfaces of the subtalar and talonavicular joint regarding to its mineralisation and to verify whether a correlation to the mechanical bone strength exists. Methods: A total of 21 cadaverous lower leg specimens were investigated. Computed tomography osteo-absorptiometry (CT-OAM) was used to display the mineralisation of the subchondral bone plate analysing its density. The mechanical strength was measured by means of indentation testing. The distribution pattern was analysed regarding their dissemination with the main focus on number and location of their maxima. The correlation of both parameters was evaluated by linear regression. Results: The mineralisation and the mechanical strength were not distributed homogenously throughout the articular surfaces but showed unique and reproducible patterns. The range of absolute values for density and strength varied in between the samples and joint surfaces, but the number and location of the maxima evaluated by both methods showed to be concurring. The coefficient of correlation of both datasets ranged from 0.76 to 0.95 (median 0.88) and showed a linear dependency. Conclusions: Density distribution and mechanical strength of the subchondral bone plate are significantly associated and can be seen as a mirror of the long-term load intake of a joint. It can be concluded that CT-OAM as a tool to visualize subchondral bone plate density distribution regarding to its mineralisation can be used to indirectly gain information about joint biomechanics in vivo by the use of conventional CT-data.

Objective Subchondral bone density distribution can be used to study joint biomechanics non-invasively. Differences in joint loading between related species can aid in the understanding of joint loading and the development of certain types of orthopaedic pathology. This study was conducted to evaluate density distribution in the subchondral bone of the talus of different Canidae species, as a parameter reflecting the long-term joint loading in the tarsocrural joint. Materials and Methods The tarsal joints of cadaveric dogs of different breeds were included, that is, German Shepherd (n = 5), Bouvier des Flandres (n = 3) and Labrador Retriever (n = 6).Additionally, golden jackals (n = 5) (Canis aureus) and wolves (n = 5) (Canis lupus) were included. Consecutive computed tomography slices were made and the subchondral bone density distribution was evaluated using computer tomographic osteoabsorptiometry. Different breeds and species were visually compared. Results Differences were found in the subchondral bone density distribution of the talus between breeds and between species (Canis familiaris, Canis lupus and Canis aureus). Discussion and Conclusion Based on the density distribution, there are differences in loading conditions of the tarsocrural joint in different species of Canidae. The joint loading distribution is very similar between dogs of the same breed and within the same species. Although between-breed differences can be explained by conformational differences, the between-species differences remain subject to further research.

Following the principles of "morphology reveals biomechanics," the cartilage-osseous interface and the trabecular network show defined adaptation in response to physiological loading. In the case of a compromised relationship, the ability to support the load diminishes and the onset of osteoarthritis (OA) may arise. To describe and quantify the changes within the subchondral bone plate (SBP) and trabecular architecture, 10 human OA patellae were investigated by CT and micro-CT. The results are presented in comparison to a previously published dataset of 10 non-OA patellae which were evaluated in the same manner. The analyzed OA samples showed no distinctive mineralization pattern in regards to the physiological biomechanics, but a highly irregular disseminated distribution. In addition, no regularity in bone distribution and architecture across the trabecular network was found. We observed a decrease of material as the bone volume and trabecular thickness/number were significantly reduced. In comparison to non-OA samples, greatest differences for all parameters were found within the first mm of trabecular bone. The differences decreased toward the fifth mm in a logarithmic manner. The interpretation of the logarithmic relation leads to the conclusion that the main impact of OA on bony structures is located beneath the SBP and lessens with depth. In addition to the clear difference in material with approximately 12% less bone volume in the first mm in OA patellae, the architectural arrangement is more rod-like and isotropic, accounting for an architectural decrease in stability and support. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1982-1989, 2017.

Objectives: Ultrasound-guided synovial biopsy is increasingly applied in rheumatology. Usually forceps- or needle-based techniques are used. So far there has been no direct comparison of different devices regarding their suitability in high resolution musculoskeletal ultrasound (hrMSUS)-guided synovial biopsy. Methods: A core needle biopsy (Quickcore, Cook Medical, Bloomington, IN, USA), an anterograde arthroscopy forceps (Karl Storz GmbH, Tuttlingen, Germany), a retrograde forceps (Retroforce, KarlStorz GmbH Tuttlingen, Germany) and an convexly shaped integrated core needle system (Synovex, Hipp Medical, Kolbingen, Germany) were tested for ultrasound-guided synovial biopsy of the suprapatellar recess in cadaver knee joints. Four senior rheumatologists scored each intervention from 0-5 regarding the following characteristics: visualization, handiness, accuracy, synovial tissue yield, invasiveness and overall suitability. Each intervention was recorded as static images and video clips. You can submit your Manuscripts at: https://symbiosisonlinepublishing.com/submitManuscript.php

Bone mineral density distribution patterns at the sacroiliac joint (SIJ) may reflect long-term adaptation patterns to the loading the joint endures. This study aims to display bone mineralisation patterns of the articular SIJ subchondral lamella using computed tomography (CT) osteoabsorptiometry and mechanical indenting, to determine whether a relationship exists between mineralisation and mechanical strength. Twenty hemipelves were CT-scanned before osteoabsorptiometry densitograms were derived. Each articular side of eleven SIJs was mechanically indented following a 10-mm grid scheme. The sacral surface displayed lower Hounsfield unit (HU) values (≤ 700 HU) than the iliac side (700 HU). The apex, superior corner and borders yielded the highest HU scores (700 HU). Penetration strength was significantly higher on the iliac side (p 0.04). Mineral density correlated positively with penetration strength of the subchondral bone layer (p 0.05). No correlations were found between the HU values, nor between penetration strength of corresponding sides of the same SIJ in the majority of cases (p 0.05). The iliac subchondral lamella is mechanically denser than the sacral aspect. The non-correlation between density and bone strength of articulating sides indicates biomechanical non-conformity. Loading throughout the SIJ may follow a complex distribution pattern involving the surrounding soft tissues, suspending the sacrum between the ilia.