The COVID-19 pandemic necessitated a pivot to online learning for many traditional, hands-on subjects such as anatomy. This, coupled with the increase in online education programmes, and the reduction of time students spend in anatomy dissection rooms, has highlighted a real need for innovative and accessible learning tools. This study describes the development of a novel 3-dimensional (3D), interactive anatomy teaching tool using structured light scanning (SLS) technology. This technique allows the 3D shape and texture of an object to be captured and displayed online, where it can be viewed and manipulated in real-time. Human bones of the upper limb, vertebrae and whole skulls were digitised using SLS using Einscan Pro2X/H scanners. The resulting meshes were then post-processed to add the captured textures and to remove any extraneous information. The final models were uploaded into Sketchfab where they were orientated, lit and annotated. To gather opinion on these models as effective teaching tools, surveys were completed by anatomy students (n=35) and anatomy educators (n=8). Data was collected using a Likert scale response, as well as free text answers to gather qualitative information. 3D scans of the scapula, humerus, radius, ulna, vertebrae and skull were successfully produced by SLS. Interactive models were produced via scan data in Sketchfab and successfully annotated to provide labelled 3D models for examination. 94% of survey respondents agreed that the interactive models were easy to use (n=35, 31% agree and 63% strongly agree) and 97% agreed that the 3D interactive models were more useful than 2D images for learning bony anatomy (n=35; 26% agree and 71% strongly agree). This initial study has demonstrated a suitable proof-of-concept for SLS technology as a useful technique for producing 3D interactive online tools for learning and teaching bony anatomy. Current studies are focussed on determining the SLS accuracy and the ability of SLS to capture soft tissue/joints. We believe that this tool will be a useful technique for generating online 3D interactive models to study orthopaedic anatomy

Degeneration of the intervertebral disc (IVD), and subsequent low back pain, is an almost inevitable cause of disability. The underlying mechanisms are complex and current therapeutic strategies mainly focus on symptomatic relief rather than on the intrinsic regeneration of the IVD. This talk will provide an overview of special anatomical features and the composition of the IVD as well as its cellular microenvironment. Selected promising conceptional regenerative approaches will be discussed.

Introduction. The equine SDFT tendon is a complex hierarchal structure that transmits force from muscle to bone and stores energy through its stretching and recoiling action. It is a common site of pathology in athletic horses. Our aim was to describe the ultrastructural anatomy of the SDFT as part of a larger programme to understand the structure-functional relationship of this tendon. Materials and Methods. Fifteen SDFT from different aged horses, sectioned transversely (2–3 mm thickness) and then photographed using Canon EOS 5D Mark III (100 mm focal length). Images processed through ImageJ and IMOD software for 3D reconstruction. Samples were also taken from the proximal, middle and distal part of the SDFT from a foetal, one and nine years old horse, processed for H&E staining and sectioned longitudinally in series into 20 sections (5µm), additionally the mid metacarpal region of one year old was fully sectioned into 250 sections. The entire cut surface on the slide was imaged and transformed to one collated image using Inkscape. Using IMOD collated photos transformed to mrc file (Z-stack) and in order to reconstruct 3D forms. Results. A tertiary fascicle was defined as a bundle of collagen fibres surrounded by a well-defined interfascicular matrix IFM (width 34.56 µm +/− 16.43 (St.Dev)). Secondary fascicles were defined as subdivisions of the tertiary fascicles (IFM width 11.1 µm +/− 4.01 (St.Dev)) (n=2). Using this classification we found that the numbers of the secondary and tertiary fascicles were not continuous through the tendon in a proximal to distal regions of the tendon. The histological 3D anatomy manifests similar fascicular structure in all ages, but their fascicular contours were less irregular in aged and in the mid-metacarpal region. The 3D anatomy of the mid-metacarpal tendon demonstrated heterogeneous fascicles, which had helical arrangement in their longitudinal axis. Discussion. Secondary and tertiary fascicles are heterogeneous in numbers, shapes and interconnections with each other in different regions. Fascicles appear to branch from proximal to distal through the tendon and are not always continuous through the tendon length. Some fascicles intercommunicating with each other and have helical configuration. Understanding the 3D anatomy will facilitate understanding of tendon structure-function relationships and injury predisposition

Purpose. Clavicular anatomy is variable and this has implications when osteosynthesis is undertaken especially while using the newer generation pre-contoured anatomical plates. This study aimed to examine the anatomy of the clavicle and its variations. Methods. One hundred and forty three clavicles of unknown origin were analysed. Photographs were taken of each clavicle. A scale and electronic callipers were used to determine specific dimensions from six predefined areas of the bone. The length, diameters of the acromial and sternal heads, the diameter of the mid-clavicular segment and depths of both the medial and lateral curvatures were obtained. Results. Clavicles studied ranged from 18.34 centimetres to 10.93 centimetres in length, with the mean length being 14.97 centimetres thus, demonstrating 7.41±1.38 centimetres variability in length between extremes of the clavicles measured. In general, left clavicles were found to be longer than right clavicles. Mid-clavicular segments showed a greater diameter on the left than right, with 1.07±0.17 centimetres difference between the extremes of diameters. The mean diameter of the sternal and acromial heads showed little variation at 2.36±0.38 centimetres and 2.54±0.47 centimetres respectively. Medial curvatures were found to be deeper than lateral curves (1.87±0.36 centimetres vs. 1.28±0.46 centimetres), although the lateral curves showed more bone to bone variation. Conclusion. The results of this study define the dimensions of the clavicle and illustrate the wide variations in its anatomy. This variability shown in large group of cadaveric specimens would be immensely helpful to consider while designing the pre-contoured anatomical plates. In addition, surgeons should note these variations in the clavicular anatomy while undertaking osteosynthesis as these variations have the potential of causing a mismatch between the newer pre-contoured plates and the fractured clavicle fixation

Introduction

The current methods for measuring femoral torsion have limitations, including variability and inaccuracies. Existing 3D methods are not reliable for abnormal femoral anteversion measurement. A new 3D method is needed for accurate measurement and planning of proximal femoral osteotomies. Currently available software for viewing and modelling CT data lacks measurement capabilities. The MSK Hip planner aims to address these limitations by combining measurement, planning, and analysis functionalities into one tool. We aim to answer 5 key questions: Is there a difference between 2D measurement methods? Is there a difference between 3D measurement methods? Is there a difference between 2D and 3D measurement methods? Are any of the measurement methods affected by the presence of osteoarthritis or a CAM deformity?

We dissected 20 cadaver hips in order to investigate the anatomy and excursion of the trochanteric muscles in relation to the posterior approach for total hip replacement. String models of each muscle were created and their excursion measured while the femur was moved between its anatomical position and the dislocated position. The position of the hip was determined by computer navigation. In contrast to previous studies which showed a separate insertion of piriformis and obturator internus, our findings indicated that piriformis inserted onto the superior and anterior margins of the greater trochanter through a conjoint tendon with obturator internus, and had connections to gluteus medius posteriorly. Division of these connections allowed lateral mobilisation of gluteus medius with minimal retraction. Analysis of the excursion of these muscles revealed that positioning the thigh for preparation of the femur through this approach elongated piriformis to a maximum of 182%, obturator internus to 185% and obturator externus to 220% of their resting lengths, which are above the thresholds for rupture of these muscles. Our findings suggested that gluteus medius may be protected from overstretching by release of its connection with the conjoint tendon. In addition, failure to detach piriformis or the obturators during a posterior approach for total hip replacement could potentially produce damage to these muscles because of over-stretching, obturator externus being the most vulnerable

We hypothesized that the finger extensor mechanism has attachments along the dorsal surface of the entire length of the proximal phalanx and that this anatomy has not been clearly defined. The attachment along the dorsal aspect of the proximal phalanx of the index, middle, index and small fingers was dissected in 20 fresh-frozen cadavers. The lateral bands and attachments along the lateral and medial surface were released to appreciate the attachments along the dorsal aspect. We characterized the ligament attachments as very robust, moderately robust, and minimally robust at the distal, middle, and proximal portions. Three orthopaedic surgeons quantified the attachment, finding that 93% of specimens had tendinous attachments and the most robust attachment found at the most proximal and distal aspects adjacent to the articular cartilage. 87% of the specimens had very robust attachments at the proximal portion of the proximal phalanx. The middle portion of the proximal phalanx had moderate to minimally robust attachments. Greatest variability in attachment was found along the most distal portion of proximal phalanx adjacent to the proximal interphalangeal joint (26% of specimens had moderate to minimal robust attachment; 74% had robust attachments). The attachments along the proximal phalanx were attached on the dorsal half of the proximal phalanx, with no fibrous attachments extending past the lateral bands. In summary, we found tendinous attachment along the proximal phalanx that may assist in finger extension and may extend the digit at the metacarpal phalangeal joint without central band contribution

Introduction. The rabbit common calcanean (Achilles) tendon is a compound apparatus frequently used in studies considering novel interventions to facilitate tendon regeneration. These studies often employ complete surgical transection of the apparatus. Due consideration of the translational relevance to human tendinopathy is often lacking and refinement of this injury model, consistent with the principles of the 3Rs, has not been forthcoming. Materials and Methods. Wild rabbit cadavers (n=10) were obtained from a licensed game dealer. For gross anatomy studies the caudal crus was dissected and transverse sections obtained every 5 mm. Ultrasongraphic examination of the entire apparatus was peformed with a 15 Hz transducer in transverse sections. Results. This study reannotates the apparatus and demonstrates that the principal structures, the superficial digital flexor tendon and medial and lateral gastrocnemius tendons, may be clearly identified by ultrasonographic examination. Discussion. Historical descriptions of the rabbit Achilles apparatus are shown to be inaccurate and follow human gross anatomical descriptions. Ultrasonographic identification of the constituent structures in the rabbit are poorly represented in the literature. Reference measurements and qualitative descriptions are provided that may facilitate the development of refined surgical techniques for in vivo studies of tendon regeneration in the rabbit beyond crude transection studies

Total hip arthroplasty is well established as a successful treatment modality for end stage arthritis, with a variety of components currently available. However, utilising traditional stemmed implants in patients with distorted proximal femoral geometry can be technically challenging with increased risk of complications. We present seven patients with distorted proximal femoral anatomy or failed hip arthroplasty in whom a technically challenging primary or revision operation was simplified by use of a Proxima stem. This is a short, stemless, metaphyseal loading implant with a pronounced lateral flare. At twelve months follow up there have been no complications with average improvement in Oxford and Harris scores of forty and forty-nine respectively. Radiological analysis shows all stems to be stable and well fixed. Designed primarily as a bone conserving implant for primary hip arthroplasty we propose that the Proxima prosthesis also be considered in cases where a conventional stemmed implant may not be suitable due to challenging proximal femoral anatomy. The use of the stemless Proxima implant provided a simple solution in seven difficult and potentially lengthy complex primary and revision hip arthroplasties with gratifying clinical and radiological outcomes

Abstract

While the evolution of the bony skeleton of the shoulder girdle is well described, there is little information regarding the soft tissues, in particular of the rotator cuff. We dissected the shoulders of 23 different species and compared the anatomical features of the tendons of the rotator cuff. The alignment and orientation of the collagen fibres of some of the tendons were also examined histologically. The behaviour of the relevant species was studied, with particular reference to the extent and frequency of forward-reaching and overhead activity of the forelimb.

In quadrupedal species, the tendons of supraspinatus, infraspinatus and teres minor were seen to insert into the greater tuberosity of the humerus separately. They therefore did not form a true rotator cuff with blending of the tendons. This was only found in advanced primates and in one unusual species, the tree kangaroo. These findings support the suggestion that the appearance of the rotator cuff in the evolutionary process parallels anatomical adaptation to regular overhead activity and the increased use of the arm away from the sagittal plane.

Anatomical descriptions of the lateral retinaculum have been published, but the attachments, name or even existence of its tissue bands and layers are ill-defined. We have examined 35 specimens of the knee. The deep fascia is the most superficial layer and the joint capsule is the deepest. The intermediate layer is the most substantial and consists of derivatives of the iliotibial band and the quadriceps aponeurosis. The longitudinal fibres of the iliotibial band merge with those of the quadriceps aponeurosis adjacent to the patella. These longitudinal fibres are reinforced by superficial arciform fibres and on the deep aspect by transverse fibres of the iliotibial band. The latter are dense and provide attachment of the iliotibial band to the patella and the tendon of vastus lateralis obliquus.

Our study identifies two important new findings which are a constant connection of the deep fascia to the quadriceps tendon superior and lateral to the patella, and, a connection of the deeper transverse fibres to the tendon of vastus lateralis obliquus.

Introduction:

The transverse acetabular ligament (TAL) antomy is not a well explored aspect of the hip joint with limited morphological description in the reviewed literature. It is often used as an anatomical landmark for orientation of the acetabular component in total hip arthroplasty (THA). There is debate as to whether it represents an appropriate guide to cup placement in THA. Present descriptions in orthopaedic literature conside it as a single plane structure to which the surgeon can align the cup. The aim of the current study was to investigate the morphology of the TAL and it was hypothesised that the current description of it being a plane would prove insufficient.

We studied the origin of the anterior deltoid from the lateral third of the clavicle and the leading anterior edge of the acromion in 18 cadaver shoulders by anatomical and histological methods.

The main origin of the deltoid was from the superior surface of the anterior acromion, but muscle and tendinous attachments were also seen on the entire anterior surface of the acromion, its anteroinferior surface and on the whole width of the anterior surface of the clavicle.

Mock arthroscopic acromioplasty was shown to detach deltoid fibres from the anterior surfaces, leaving the superior attachment in continuity. Potentially, arthroscopic subacromial and clavicular resection can detach deltoid fibres originating from the anterior and anteroinferior surfaces of the acromion and clavicle and thus weaken the anterior deltoid.

While the COVID-19 pandemic highlighted the need for more accessible anatomy instruction tools, it is also well known that the time allocated to practical anatomy teaching has reduced in the past decades. Notably, the opportunity for anatomy students to learn osteology is not prioritised, nor is the ability of students to appreciate osteological variation. As a potential method of increasing accessibility to bone models, this study describes the process of developing 3D-printed replicas of human bones using a combination of structured light scanning (SLS) technology and 3D printing. Human bones were obtained from the Anatomy Lab at the University of Edinburgh and were digitised using SLS via an Einscan H scanner. The resulting data was then used to print multiple replicas of varying materials, colours, scales and resolutions on an Ultimaker S3 3D printer. To gather opinion on these models and their variables, surveys were completed by anatomy students and educators (n=57). Data was collected using a Likert scale response, as well as free-text answers to gather qualitative information. 3D scans of the scapula, atlas (C1 vertebrae) and femur were successfully obtained. Plastic replicas were produced with defined variables in 4 separate stations e.g. different colours, to obtain results from survey respondents. For colour, 87.7% of survey respondents preferred white models, with 7% preferring orange and 5.3% preferring blue. For material, 47.4% of respondents preferred PLA (Polylactic acid), while 33.3% preferred ABS (Acrylonitrile butadiene styrene), 12.3% preferred Pet-G (Polyethylene terephthalate glycol), 3.5% preferred Glassbend and 3.5% had no preference. Additional results based on scale and resolution were also collected. This initial study has demonstrated a proof-of-concept workflow for SLS technology to be combined with 3D printing to produce plastic replicas of human bones. Our study has provided key information about the colour, scale, material and resolution required for these models. Our future work will focus on determining accuracy of the models and their use as teaching aids for osteology education

In the last years, 3d printing has progressively grown and it has reached a solid role in clinical practice. The main applications brought by 3d printing in orthopedic surgery are: preoperative planning, custom-made surgical guides, custom-made im- plants, surgical simulation, and bioprinting. The replica of the patient's anatomy, starting from the elaboration of medical volumetric images (CT, MRI, etc.), allows a progressive extremization of treatment personalization that could be tailored for every single patient. In complex cases, the generation of a 3d model of the patient's anatomy allows the surgeons to better understand the case — they can almost “touch the anatomy” —, to perform a more ac- curate preoperative planning and, in some cases, to perform device positioning before going to the surgical room (i.e. joint arthroplasty). 3d printing is also commonly used to produce surgical cutting guides, these guides are positioned intraoperatively on given landmarks to guide the surgeon to perform a specific surgical act (bone osteotomy, bone resection, implant position, etc.). In total knee arthroplasty, custom-made cutting guides have been developed to help the surgeon align the femoral and tibial components to the pre-arthritic condition with- out the use of the intramedullary femoral guide. 3d printed custom-made implants represent an emerging alternative to biological reconstructions especially after oncologic resection surgery or in case of complex arthroplasty revision surgery. Custom-made implants are designed to re- place the original shape and size of the patient's bone and they allow an extreme personalization of the treatment for every single patient. Patient-specific surgical simulation is a new frontier that promises great benefits for surgical training. a solid 3d model of the patient's anatomy can faithfully reproduce the surgical complexity of the patient and it allows to generate surgical simulators with increasing difficulty to adapt the difficulties of the course with the level of the trainees performing structured training paths: from the “simple” case to the “complex” case

Variations in pelvic anatomy are a major risk factor for misplaced percutaneous sacroiliac screws used to treat unstable posterior pelvic ring injuries. A better understanding of pelvic morphology improves preoperative planning and therefore minimises the risk of malpositioned screws, neurological or vascular injuries, failed fixation or malreduction. Hence a classification system which identifies the clinically important anatomical variations of the sacrum would improve communication among pelvic surgeons and inform treatment strategy. 300 Pelvic CT scans from skeletally mature trauma patients that did not have pre-existing posterior pelvic pathology were identified. Axial and coronal transosseous corridor widths at both S1 and S2 were recorded. Additionally, the S1 lateral mass angle were also calculated. Pelvises were classified based upon the sacroiliac joint (SIJ) height using the midpoint of the anterior cortex of L5 as a reference point. Four distinct types could be identified:. Type-A – SIJ height is above the midpoint of the anterior cortex of the L5 vertebra. Type-B – SIJ height is between the midpoint and the lowest point of the anterior cortex of the L5 vertebra. Type-C – SIJ height is below the lowest point of the anterior cortex of the L5 vertebra. Type-D – a subgroup for those with a lumbosacral transitional vertebra, in particular a sacralised L5. Differences in transosseous corridor widths and lateral mass angles between classification types were assessed using two-way ANOVAs. Type-B was the most common pelvic type followed by Type-A, Type-C, and Type-D. Significant differences in the axial and coronal corridors was observed for all pelvic types at each level. Lateral mass angles increased from Types-A to C, but were smaller in Type-D. This classification system offers a guide to surgeons navigating variable pelvic anatomy and understanding how it is associated with the differences in transosseous sacral corridors. It can assist surgeons’ preoperative planning of screw position, choice of fixation or the need for technological assistance

To ensure clinical relevance, the in vitro engineering of tissues for implantation requires artificial replacements to possess properties similar to native anatomy. Our overarching study is focussed on developing a bespoke bone-tendon in vitro model replicating the anatomy at the flexor digitorum profundus (FDP) tendon insertion site at the distal phalanx. Anatomical morphometric analysis has guided FDP tendon model design consisting of hard and soft tissue types. Here, we investigate potential materials for creation of the model's bone portion by comparison of two bone cements; brushite and genex (Biocomposites Ltd). 3D printed molds were prepared based on anatomical morphometric analysis of the FDP tendon insertion site and used to cast identical bone blocks from brushite and genex cements. Studies assessing the suitability of each cement type were conducted e.g. setting times, pH on submersion in culture medium and interaction with fibrin gels. Data was collected using qualitative imaging and qualitative measurements (N=3,n=6) for experimental conditions. Both brushite (BC) and genex (GC) cements could be cast into bespoke molds, producing individual blocks and were mixed/handled with appropriate setting times. On initial submersion in culture medium, BC caused a reduction in pH values (7.49 [control]) to 6.85) while GC remained stable (7.59). Reduction in pH value also affected fibrin gel interaction where gel was seen to be detaching/not forming around BC and medium discolouration was noted. This was not observed in GC. While GC outperformed BC in initial tests, repeated washing of BC led to pH stabilisation (7.5,3xwashes), consistent with their further use in this model. This study has compared BC and GC as materials for bone block production. Both materials show promise, and current work assessing material properties and cell proliferation are needed to inform our choice for use in our FDP-tendon-bone interface model. This research was supported by an ORUK Studentship award (ref:533). Genex was kindly provided by Biocomposites, Ltd

Abstract. The lateral ligaments of the ankle composed of the anterior talofibular (ATFL), calcaneofibular (CFL) and posterior talofibular ligaments (PTFL), are amongst the most commonly injured ligaments of the human body. Although treatment methods have been explored exhaustively, healing outcomes remain poor with high rates of re-injury, chronic ankle instability and pain persisting. The introduction and application of tissue engineering methods may target poor healing outcomes and eliminate long-term complications, improving the overall quality of life of affected individuals. For any surgical procedure or tissue-engineered replacement to be successful, a comprehensive understanding of the complete anatomy of the native structure is essential. Knowledge of the dimensions of ligament footprints is vitally important for surgeons as it guides the placement of bone tunnels during repair. It is also imperative in tissue-engineered design as the creation of a successful replacement relies on a thorough understanding of the native anatomy and microanatomical structure. Several studies explore techniques to describe ligament footprints around the body, with limited studies describing in-depth footprint dimensions of the ATFL, CFL and PTFL. Techniques currently used to measure ligament footprints are complex and require resources which may not be readily available, therefore a new methodology may prove beneficial. Objectives. This study explores the application of a novel technique to assess the footprint of ankle ligaments through a straightforward inking method. This method aims to enhance surgical technique and contribute to the development of a tissue-engineered analogue based on real anatomical morphometric data. Methods. Cadaveric dissection of the ATFL, CFL and PTFL was performed on 12 unpaired fresh frozen ankles adhering to regulations of the Human Tissue (Scotland) Act. The ankle complex with attaching ligaments was immersed in methylene blue. Dissection of the proximal and distal entheses of each ligament was carried out to reveal the unstained ligament footprint. Images of each ligament footprint were taken, and the area, length and width of each footprint were assessed digitally. Results. The collective area of the proximal entheses of the ATFL, CFL and PTFL measures 142.11 ± 12.41mm2. The mean areas of the superior (SB) and inferior band (IB) of the distal enthesis of the ATFL measured 41.72 ± 5.01mm2 and 26.66 ± 3.12mm2 respectively. The footprint of the distal enthesis of the CFL measured 146.07 ± 14.05mm2, while the footprint of the distal PTFL measured 126.26 ± 8.88mm2. The proximal footprint of the ATFL, CFL and PTFL measured 11.06 ± 0.69mm, 7.87 ± 0.43mm and 10.52 ± 0.63mm in length and 8.66 ± 0.50mm, 9.10 ± 0.92mm and 14.41 ± 1.30mm in width on average. The distal footprint of the ATFL (SB), ATFL (IB), CFL and PTFL measured 10.92 ± 0.81 mm, 8.46 ± 0.46mm, 13.98 ± 0.93mm and 11.25 ± 0.95mm in length and 7.76 ± 0.59mm, 7.51 ± 0.64mm, 18.98 ± 1.15mm and 24.80 ± 1.25mm in width on average. Conclusions. This methodology provides an effective approach in the identification of the footprint of the lateral ligaments of the ankle to enhance surgical precision and accuracy in tissue-engineered design. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

The Anterior Cruciate Ligament (ACL) plays a vital role in maintaining function and stability in the knee. Over the last several decades, much research has been focused on elucidating the anatomy, structural properties, biomechanics, pathology, and optimal treatments for the ACL. Through careful and objective study, the ACL can be understood to be a dynamic structure, rich in neurovascular supply. Although it is referred to as one ligament, it is comprised of two dis-tinct bundles which function synergistically to facilitate normal knee kinematics. The bony morphology of the knee defines normal knee kinematics, as well as the nature of the soft-tissue structures about the knee. Characterized by individual uniqueness, bony morphology varies from patient to patient. The ACL, which is a reflection of each patient's unique bony morphol-ogy, is inherently subject to both anatomic and morphologic variation as well. Furthermore, the ACL is subject to physiologic aging, which can affect the anatomic and structural properties of the ligament over time. A successful anatomic ACL Reconstruction, which may be considered the functional restoration of the ACL to its native dimensions, collagen orientation, and inser-tion sites according to individual anatomy, considers all these principles. It is vital to respect the nature we observe, rather than to “create” nature to fit a one-size-fits-all surgery. Double bundle ACL Reconstruction may therefore be thought of more as a concept rather than a specific technique, one that respects the individual unique anatomy of each patient to provide a truly indi-vidualized, anatomic, and value-based ACL Reconstruction