Aims. Despite the expansion of arthroscopic surgery of the shoulder, the open deltopectoral approach is increasingly used for the fixation of fractures and arthroplasty of the shoulder. The anatomy of the terminal branches of the posterior circumflex humeral artery (PCHA) has not been described before. We undertook an investigation to correct this omission. Patients and Methods. The vascular anatomy encountered during 100 consecutive elective deltopectoral approaches was recorded, and the common variants of the terminal branches of the PCHA are described. Results. In total, 92 patients (92%) had a terminal branch that crossed the space between the deltoid and the proximal humerus and which was therefore vulnerable to tearing or avulsion during the insertion of the blade of a retractor during the deltopectoral approach to the shoulder. In 75 patients (75%) there was a single vessel, in 16 (16%) a double vessel and in one a triple vessel. Conclusion. The relationship of these vessels to the landmark of the tendon of the insertion of pectoralis major into the proximal humerus is described. Damage to these previously undocumented branches can cause persistent bleeding leading to prolonged surgery and post-operative haematoma and infection, as well as poor visualisation during the procedure. Cite this article: Bone Joint J 2016;98-B:1395–8

The piriformis muscle is an important landmark in the surgical anatomy of the hip, particularly the posterior approach for total hip replacement (THR). Standard orthopaedic teaching dictates that the tendon must be cut in to allow adequate access to the superior part of the acetabulum and the femoral medullary canal. However, in our experience a routine THR can be performed through a posterior approach without sacrificing this tendon. We dissected the proximal femora of 15 cadavers in order to clarify the morphological anatomy of the piriformis tendon. We confirmed that the tendon attaches on the crest of the greater trochanter, in a position superior to the trochanteric fossa, away from the entry point for broaching the intramedullary canal during THR. The tendon attachment site encompassed the summit and medial aspect of the greater trochanter as well as a variable attachment to the fibrous capsule of the hip joint. In addition we dissected seven cadavers resecting all posterior attachments except the piriformis muscle and tendon in order to study their relations to the hip joint, as the joint was flexed. At flexion of 90° the piriformis muscle lay directly posterior to the hip joint. The piriform fossa is a term used by orthopaedic surgeons to refer the trochanteric fossa and normally has no relation to the attachment site of the piriformis tendon. In hip flexion the piriformis lies directly behind the hip joint and might reasonably be considered to contribute to the stability of the joint. We conclude that the anatomy of the piriformis muscle is often inaccurately described in the current surgical literature and terms are used and interchanged inappropriately. Cite this article: Bone Joint J 2013;95-B:764–9

Anterior cruciate ligament (ACL) reconstruction is commonly performed and has been for many years. Despite this, the technical details related to ACL anatomy, such as tunnel placement, are still a topic for debate. In this paper, we introduce the flat ribbon concept of the anatomy of the ACL, and its relevance to clinical practice. Cite this article: Bone Joint J 2016;98-B:1020–6

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

Novel immersive virtual reality (IVR) technologies are revolutionizing medical education. Virtual anatomy education using head-mounted displays allows users to interact with virtual anatomical objects, move within the virtual rooms, and interact with other virtual users. While IVR has been shown to be more effective than textbook learning and 3D computer models presented in 2D screens, the effectiveness of IVR compared to cadaveric models in anatomy education is currently unknown. In this study, we aim to compare the effectiveness of IVR with direct cadaveric bone models in teaching upper and lower limb anatomy for first-year medical students. A randomized, double-blind crossover non-inferiority trial was conducted. Participants were first-year medical students from a single University. Exclusion criteria included students who undertook prior undergraduate or graduate degrees in anatomy. In the first stage of the study, students were randomized in a 1:1 ratio to IVR or cadaveric bone groups studying upper limb skeletal anatomy. All students were then crossed over and used cadaveric bone or IVR to study lower limb skeletal anatomy. All students in both groups completed a pre-and post-intervention knowledge test. The educational content was based on the University of Toronto Medical Anatomy Curriculum. The Oculus Quest 2 Headsets (Meta Technologies) and PrecisionOS Anatomy application (PrecisionOS Technology) were utilized for the virtual reality component. The primary endpoint of the study was student performance on the pre-and post-intervention knowledge tests. We hypothesized that student performance in the IVR groups would be comparable to the cadaveric bone group. 50 first-year medical students met inclusion criteria and were computer randomized (1:1 ratio) to IVR and cadaveric bone group for upper limb skeletal anatomy education. Forty-six students attended the study, 21 completed the upper limb modules, and 19 completed the lower limb modules. Among all students, average score on the pre-intervention knowledge test was 14.6% (Standard Deviation (SD)=18.2%) and 25.0% (SD=17%) for upper and lower limbs, respectively. Percentage increase in students’ scores between pre-and post-intervention knowledge test, in the upper limb for IVR, was 15 % and 16.7% for cadaveric bones (p = 0. 2861), and for the lower limb score increase was 22.6% in the IVR and 22.5% in the cadaveric bone group (p = 0.9356). In this non-inferiority crossover randomized controlled trial, we found no significant difference between student performance in knowledge tests after using IVR or cadaveric bones. Immersive virtual reality and cadaveric bones were equally effective in skeletal anatomy education. Going forward, with advances in VR technologies and anatomy applications, we can expect to see further improvements in the effectiveness of these technologies in anatomy and surgical education. These findings have implications for medical schools having challenges in acquiring cadavers and cadaveric parts

Novel immersive virtual reality (IVR) technologies are revolutionizing medical education. Virtual anatomy education using head-mounted displays allows users to interact with virtual anatomical objects, move within the virtual rooms, and interact with other virtual users. While IVR has been shown to be more effective than textbook learning and 3D computer models presented in 2D screens, the effectiveness of IVR compared to cadaveric models in anatomy education is currently unknown. In this study, we aim to compare the effectiveness of IVR with direct cadaveric bone models in teaching upper and lower limb anatomy for first-year medical students. A randomized, double-blind crossover non-inferiority trial was conducted. Participants were first-year medical students from a single University. Exclusion criteria included students who undertook prior undergraduate or graduate degrees in anatomy. In the first stage of the study, students were randomized in a 1:1 ratio to IVR or cadaveric bone groups studying upper limb skeletal anatomy. All students were then crossed over and used cadaveric bone or IVR to study lower limb skeletal anatomy. All students in both groups completed a pre-and post-intervention knowledge test. The educational content was based on the University of Toronto Medical Anatomy Curriculum. The Oculus Quest 2 Headsets (Meta Technologies) and PrecisionOS Anatomy application (PrecisionOS Technology) were utilized for the virtual reality component. The primary endpoint of the study was student performance on the pre-and post-intervention knowledge tests. We hypothesized that student performance in the IVR groups would be comparable to the cadaveric bone group. 50 first-year medical students met inclusion criteria and were computer randomized (1:1 ratio) to IVR and cadaveric bone group for upper limb skeletal anatomy education. Forty-six students attended the study, 21 completed the upper limb modules, and 19 completed the lower limb modules. Among all students, average score on the pre-intervention knowledge test was 14.6% (Standard Deviation (SD)=18.2%) and 25.0% (SD=17%) for upper and lower limbs, respectively. Percentage increase in students’ scores between pre-and post-intervention knowledge test, in the upper limb for IVR, was 15 % and 16.7% for cadaveric bones (p = 0. 2861), and for the lower limb score increase was 22.6% in the IVR and 22.5% in the cadaveric bone group (p = 0.9356). In this non-inferiority crossover randomized controlled trial, we found no significant difference between student performance in knowledge tests after using IVR or cadaveric bones. Immersive virtual reality and cadaveric bones were equally effective in skeletal anatomy education. Going forward, with advances in VR technologies and anatomy applications, we can expect to see further improvements in the effectiveness of these technologies in anatomy and surgical education. These findings have implications for medical schools having challenges in acquiring cadavers and cadaveric parts

Introduction. Tibial nerve anatomy has not been studied profoundly in comparison to Tarsal Tunnel Syndrome (TTS). Assuming symptoms are caused by an anatomical variant or mechanical cause regarding the tibial nerve, it is essential to investigate the anatomy of this structure taking in consideration that surgical and conservative treatments have shown poor results. Methods. 40 lower-leg specimens were obtained. Dissection started 20 centimeters proximal to the Dellon-McKinnon (DM) line towards the medial aspect of the naviculo-cuneiform joint distally. Anteriorly, dissection began at the tibio-talar medial gutter until the medial aspect of the Achilles tendon posteriorly. The plantar aspect extended from medial to lateral within the parameters previously described, ending at the level of the second metatarsal. Results. The flexor retinaculum had a denser consistency in 22.5% of the cases and the average length was 51.9 mm. The flexor retinaculum as an independent structure was found absent and 77.2% of cases as undistinguished extension of the crural fascia. The lateral plantar nerver (LPN) and abductor digiti minimi (ADM) nerve shared same origin in 80% of cases, 34.5% bifurcated proximal to the DM line, 31.2% distally and 34.3% at the same level. The medial calcaneal nerve (MCN) emerged proximal to the DM line in 100% of specimens. The medial plantar nerve (MPN) has its origin proximal to the DM line in 95% of cases. Conclusion. The flexor retinaculum is an extension of the crural fascia and not an independent structure. The LPN and ADM have the same origin in most cases and this presents as an important finding that must be studied in detail for clinical correlations between the motor and sensatory affections of the ADM and LPN respectively. Finally, the branches of the MCN and MPN are the most constant in their distribution and proximal origin in relation to the Dellon-McKinnon line

Aims. The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. Methods. An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups. Results. The pre- to postoperative changes in joint anatomy were significantly less in patients undergoing bi-UKA in all three planes in both the femur and tibia, except for femoral sagittal component orientation in which there was no difference. Overall, for the six parameters of alignment (three femoral and three tibial), 47% of bi-UKAs and 24% TKAs had a change of < 2° (p = 0.045). The change in HKAA towards neutral in varus and valgus knees was significantly less in patients undergoing bi-UKA compared with those undergoing TKA (p < 0.001). Alignment was neutral in those undergoing TKA (mean 179.5° (SD 3.2°)) while those undergoing bi-UKA had mild residual varus or valgus alignment (mean 177.8° (SD 3.4°)) (p < 0.001). Conclusion. Robotic-assisted, cruciate-sparing bi-UKA maintains the natural anatomy of the knee in the coronal, sagittal, and axial planes better, and may therefore preserve normal joint kinematics, compared with a mechanically aligned TKA. This includes preservation of coronal joint line obliquity. HKAA alignment was corrected towards neutral significantly less in patients undergoing bi-UKA, which may represent restoration of the pre-disease constitutional alignment (p < 0.001). Cite this article: Bone Joint J 2020;102-B(11):1511–1518

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs. Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures. We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons). We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs. Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures. We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons). We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries

Introduction. The treatment of posterior malleolar fractures is developing. Mason and Molloy (Foot Ankle Int. 2017 Nov;38(11):1229-1235) identified only 49% of posterior malleolar rotational pilon type fractures had syndesmotic instabilities. This was against general thinking that fixation of such a fragment would stabilize the syndesmosis. Methods. We examined 10 cadaveric lower limbs that had been preserved for dissection at the Human Anatomy and Resource Centre at Liverpool University in a solution of formaldehyde. The lower limbs were carefully dissected to identify the ligamentous structures on the posterior aspect of the ankle. To compare the size to the rotational pilon posterior malleolar fracture (Mason and Molloy 2A and B) we gathered information from our posterior malleolar fracture database. 3D CT imaging was analysed using our department PACS system. Results. The PITFL insertion on the posterior aspect of the tibia is very large. The average size of insertion was 54.9×47.1mm across the posterior aspect of the tibia. Medially the PITFL blends into the sheath of tibialis posterior and laterally into the peroneal tendon sheath. 78 posterior lateral and 35 posterior medial fragments were measured. On average, the lateral to medial size of the posteromalleolar fragment was 24.5mm in the posterolateral fragment, and 43mm if there is a posteromedial fragment present also. The average distal to proximal size of the posterolateral fragment was 24.5mm and 18.5mm for the posteromedial fragment. Conclusion. The PITFL insertion on the tibia is broad. In comparison to the average size of the posterior malleolar fragments, the PITFL insertion is significantly bigger. Therefore, for a posterior malleolar fracture to cause posterior syndesmotic instability, a ligamentous injury will also have to occur. This explains the finding by Mason and Molloy that only 49% of type 2 injuries had a syndesmotic injury on testing

Introduction. The constitutional knee anatomy in the coronal plane includes the distal femoral joint line obliquity (DFJLO) which in most patients is in slight valgus positioning. Despite this native anatomy, the mechanical positioning of the femoral component during primary total knee arthroplasty (TKA) often ignores the native DFJLO opting to place the femur in a set degree of valgus that varies upon the practitioner's practice and experience. Unfortunately, this technique is likely to generate high rate of distal lateral femoral overstuffing. This anatomical mismatch might be a cause of anterior knee pain and therefore partly explain the adverse functional outcomes of mechanically aligned (MA) TKA. Our study aims at assessing the relationship between constitutional knee anatomy and clinical outcomes of MA TKA. We hypothesized that a negative relationship would be found between the constitutional frontal knee deformity, the distal femoral joint line obliquity, and functional outcomes of MA TKA with a special emphasize on patellofemoral (PF) specific outcomes. Methods. One hundred and thirteen patients underwent MA TKA (posterior-stabilized design) for primary end-stage knee osteoarthritis. They were prospectively followed for one year using the New KSS 2011 and HSS Patella score. Residual anterior knee pain was also assessed. Knee phenotypes using anatomical parameters (such as HKA, HKS, DFJLO and LDFA (Lateral distal femoral angle)) were measured from preoperative and postoperative lower-limb EOS® images (Biospace, Paris, France). We assessed the relationship between the knee anatomical parameters and the functional outcome scores at 1 year postoperatively. Results. We investigated four groups according to the preoperative obliquity of the distal femur and HKA. The group with high DFJLO and varus knee deformity demonstrated lower HSS scores (drop>10%, p=0.03) and higher rate of anterior knee pain (p=0.03). Higher postoperative variation of LDFA was associated with lower HSS scores (r = −0.2367, p=0.03) and with higher preoperative DFJLO (p=0.0001) due to the MA technique. Knee phenotypes with LDFA<87° presented higher risk of variation of LDFA. No correlation was found using New KSS 2011 outcomes at one-year follow-up. Discussion/Conclusion. Disregard of the constitutional knee anatomy (LDFA and DFJLO) when performing a MA TKA may generate a non-physiologic knee kinematics that impact patellofemoral outcomes and resulting in residual anterior knee pain. While these results are restricted to modern posterior-stabilized TKA design, recent in silico and in vitro studies supported the negative effect of the lateral overstuffing of the femoral component in the coronal plane during knee flexion. This study provides further evidence that suggest patient-specific anatomical considerations are needed to optimize component position and subsequent outcomes following primary TKA. Additional studies are needed to integrate the rotational status of the femoral component in this analysis. For any figures or tables, please contact authors directly

Introduction. Variation in resection thickness of the femur in Total Knee Arthroplasty (TKA) impacts the flexion and extension tightness of the knee. Less well investigated is how variation in patient anatomy drives flexion or extension tightness pre- and post- operatively. Extension and flexion stability of the post TKA knee is a function of the tension in the ligaments which is proportional to the strain. This study sought to investigate how femoral ligament offset relates to post-operative navigation kinematics and how outcomes are affected by component position in relation to ligament attachment sites. Method. A database of TKA patients operated on by two surgeons from 1-Jan-2014 who had a pre-operative CT scan were assessed. Bone density of the CT scan was used to determine the medial and lateral collateral attachments. Navigation (OmniNav, Raynham, MA) was used in all surgeries, laxity data from the navigation unit was paired to the CT scan. 12-month postoperative Knee Osteoarthritis and Outcome Score (KOOS) score and a postoperative CT scan were taken. Preoperative segmented bones and implants were registered to the postoperative scan to determine change in anatomy. Epicondylar offsets from the distal and posterior condyles (of the native knee and implanted components), resections, maximal flexion and extension of the knee and coronal plane laxity were assessed. Relationships between these measurements were determined. Surgical technique was a mix of mechanical gap balancing and kinematically aligned knees using Omni (Raynham, MA) Apex implants. Results. 119 patients were identified in the database. 60% (71) were female and the average age was 69.0 years (+/− 8.1). The average distal femoral bone resection was 7.5 mm (+/− 1.6) medially and 5.4 mm (+/− 2.1) laterally, and posterior 10.2 mm (+/− 1.7) medially and 8.4 mm (+/− 1.8) laterally, with implant replacement thicknesses 9 mm distally and 11 mm posterior. Maximum flexion of the knee post implantation was 121.5° (+/− 8.1) from a preoperative value of 117.9° (+/− 9.5). Change in the collateral ligament offsets brought on by surgery had significant correlations with several laxity and flexion measures. Increase in the posterior offset of the medial collateral attachment brought on by surgery was shown to decrease the maximum flexion attained (coefficient = −0.53, p < 0.001), Figure 1. Increased distal medial offset post-operatively compared to the posterior offset is significantly correlated with improved KOOS pain outcomes (coefficient = 0.23, p = 0.01). Similarly, a decrease in the distal offset of the lateral collateral ligament increased the coronal plane laxity in extension (coefficient = 0.37, p < 0.001), while the posterior lateral resection was observed to correlate with postoperative coronal laxity in flexion (coefficient = 0.42, p < 0.001). Conclusions. Accounting for variation in ligament offset during surgically planning may improve balancing outcomes. Although new alignment approaches, such as kinematic alignment, have been able to demonstrate improvements in short term outcomes, elimination of postoperative dissatisfaction has not been achieved. The interaction of an alignment strategy with a given patient's specific anatomy may be the key to unlocking further TKA patient outcome gains

Primary total hip replacement (THR) in patients with abnormal/altered proximal femoral anatomy/narrow canals presents a technical challenge. There are only limited standard prosthetic stems available to deal with narrow canals or abnormal morphology. Many prefer to use expensive custom implants which often have a lag time to manufacture and do not always have long term published outcomes. We present results of the Asian C-stem (which is a standard implant available on the shelf) used in patients predominantly of Caucasian origin with abnormal proximal femoral anatomy. We retrospectively reviewed clinic-radiological results of 131 patients (131 stems) who underwent primary THR using Asian C-stem at Wrightington Hospital till their latest follow up. Revision for any reason was considered as primary end point. Mean age at surgery was 50.8 years (16 – 80). The 2 commonest indications were primary osteoarthritis (66 patients) and hip dysplasia (54 patients). Mean follow up was 43.5 months with a minimum follow up of 12 months and maximum follow up of 97 months. There were 2 recurrent dislocations and 1 hip subluxed twice. One dislocation needed revision surgery. 1 patient underwent acetabular revision for loosening. There was no stem failure, obvious loosening or loss of fixation in any patients in our series with regards to the Asian C-stem. There were no infections and intra-operative perforations or fractures. C-stem Asian is a reliable implant for patients undergoing THR with abnormal proximal femoral anatomy or narrow canals. Long term follow up is essential

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

Aims. Restoring the pre-morbid anatomy of the proximal humerus is a goal of anatomical shoulder arthroplasty, but reliance is placed on the surgeon’s experience and on anatomical estimations. The purpose of this study was to present a novel method, ‘Statistical Shape Modelling’, which accurately predicts the pre-morbid proximal humeral anatomy and calculates the 3D geometric parameters needed to restore normal anatomy in patients with severe degenerative osteoarthritis or a fracture of the proximal humerus. Materials and Methods. From a database of 57 humeral CT scans 3D humeral reconstructions were manually created. The reconstructions were used to construct a statistical shape model (SSM), which was then tested on a second set of 52 scans. For each humerus in the second set, 3D reconstructions of four diaphyseal segments of varying lengths were created. These reconstructions were chosen to mimic severe osteoarthritis, a fracture of the surgical neck of the humerus and a proximal humeral fracture with diaphyseal extension. The SSM was then applied to the diaphyseal segments to see how well it predicted proximal morphology, using the actual proximal humeral morphology for comparison. Results. With the metaphysis included, mimicking osteoarthritis, the errors of prediction for retroversion, inclination, height, radius of curvature and posterior and medial offset of the head of the humerus were 2.9° (± 2.3°), 4.0° (± 3.3°), 1.0 mm (± 0.8 mm), 0.8 mm (± 0.6 mm), 0.7 mm (± 0.5 mm) and 1.0 mm (± 0.7 mm), respectively. With the metaphysis excluded, mimicking a fracture of the surgical neck, the errors of prediction for retroversion, inclination, height, radius of curvature and posterior and medial offset of the head of the humerus were 3.8° (± 2.9°), 3.9° (± 3.4°), 2.4 mm (± 1.9 mm), 1.3 mm (± 0.9 mm), 0.8 mm (± 0.5 mm) and 0.9 mm (± 0.6 mm), respectively. Conclusion. This study reports a novel, computerised method that accurately predicts the pre-morbid proximal humeral anatomy even in challenging situations. This information can be used in the surgical planning and operative reconstruction of patients with severe degenerative osteoarthritis or with a fracture of the proximal humerus. Cite this article: Bone Joint J 2017;99-B:927–33

There is an increasing acceptance that the clinical outcomes following posterior malleolar fractures are less than satisfactory. Current ankle classification systems do not account for differences in fracture patterns or injury mechanisms, and as such, the clinical outcomes of these fractures are difficult to interpret. The aim of this study was to analyse our posterior malleolar fractures to better understand the anatomy of the fracture. In a series of 42 consecutive posterior malleolar, who all underwent CT imaging, we have described anatomically different fracture patterns dictated by the direction of the force and dependent on talus loading. We found 3 separate categories. Type 1 – a rotational injury in an unloaded talus resulted in an extraarticular posterior avulsion of the posterior ligaments. This occurred in 10 patients and was most commonly associated with either a high fibular spiral fracture or a low fibular fracture with Wagstaffe fragment avulsion. The syndesmosis was usually disrupted in these patients. Type 2 – a rotational injury in a loaded talus resulting in a posterolateral articular fracture, of the posterior incisura. This occurred in 16 patients and was most commonly associated with a posterior syndesmosis injury, low fibular spiral fracture and an anterior collicular fracture of the medial malleolus. Type 3 – axially loaded talus in plantarflexion causing a posterior pilon. This occurred in 16 patients and was most commonly associated with a long oblique fracture of the fibular and a Y shape fracture of the medial malleolus. The syndesmosis was usually intact in these patients. In conclusion, the anatomy of the posterior malleolar should not be underestimated and requires careful consideration during treatment and categorisation in outcome studies to prevent misinterpretation

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

The inferior gluteal artery is described in standard anatomy textbooks as contributing to the blood supply of the hip through an anastomosis with the medial femoral circumflex artery. The site(s) of the anastomosis has not been described previously. We undertook an injection study to define the anastomotic connections between these two arteries and to determine whether the inferior gluteal artery could supply the lateral epiphyseal arteries alone. From eight fresh-frozen cadaver pelvic specimens we were able to inject the vessels in 14 hips with latex moulding compound through either the medial femoral circumflex artery or the inferior gluteal artery. Injected vessels around the hip were then carefully exposed and documented photographically. In seven of the eight specimens a clear anastomosis was shown between the two arteries adjacent to the tendon of obturator externus. The terminal vessel arising from this anastomosis was noted to pass directly beneath the posterior capsule of the hip before ascending the superior aspect of the femoral neck and terminating in the lateral epiphyseal vessels. At no point was the terminal vessel found between the capsule and the conjoined tendon. The medial femoral circumflex artery receives a direct supply from the inferior gluteal artery immediately before passing beneath the capsule of the hip. Detailed knowledge of this anatomy may help to explain the development of avascular necrosis after hip trauma, as well as to allow additional safe surgical exposure of the femoral neck and head

Background. Degeneration of the shoulder joint is a frequent problem. There are two main types of shoulder degeneration: Osteoarthritis and cuff tear arthropathy (CTA) which is characterized by a large rotator cuff tear and progressive articular damage. It is largely unknown why only some patients with large rotator cuff tears develop CTA. In this project, we investigated CT data from ‘healthy’ persons and patients with CTA with the help of 3D imaging technology and statistical shape models (SSM). We tried to define a native scapular anatomy that predesignate patients to develop CTA. Methods. Statistical shape modeling and reconstruction:. A collection of 110 CT images from patients without glenohumeral arthropathy or large cuff tears was segmented and meshed uniformly to construct a SSM. Point-to-point correspondence between the shapes in the dataset was obtained using non-rigid template registration. Principal component analysis was used to obtain the mean shape and shape variation of the scapula model. Bias towards the template shape was minimized by repeating the non-rigid template registration with the resulting mean shape of the first iteration. Eighty-six CT images from patients with different severities of CTA were analyzed by an experienced shoulder surgeon and classified. CT images were segmented and inspected for signs of glenoid erosion. Remaining healthy parts of the eroded scapulae were partitioned and used as input of the iterative reconstruction algorithm. During an iteration of this algorithm, 30 shape components of the shape model are optimized and the reconstructed shape is aligned with the healthy parts. The algorithm stops when convergence is reached. Measurements. Automatic 3D measurements were performed for both the healthy and reconstructed shapes, including glenoid version, inclination, offset and critical shoulder angle. These measurements were manually performed on the mean shape of the shape model by a surgeon, after which the point-to-point correspondence was used to transfer the measurements to each shape. Results. The critical shoulder angle was found to be significantly larger for the CTA scapulae compared to the references (P<0.01). When analyzing the classified scapulae significant differences were found for the version angle in the scapulae of group 4a/4b and the critical shoulder angle of group 3 when compared to the references (P<0.05). Conclusion. Patients with CTA have a larger critical shoulder angle compared with reference patients. Some significant differences are found between the scapulae from patients in different stages of CTA and healthy references, however the differences are smaller than the accuracy of the SSM reconstruction. Therefore, we are unable to conclude that there is a predisposing anatomy in terms of glenoid version, inclination or offset for CTA

Background: To stimulate a debate as to whether neurological compromise as a result of spinal instrumentation is the result of direct or indirect cord injury of more the result of cord ischaemia due to the highly abnormal vascular anatomy encountered in these patients. Methods: Review of three cases of neuromuscular scoliosis who underwent angiograms under general anaesthetic. Graphical comparisons with normal patterns spinal vascular anatomy. Results: Vascular anatomy was found to be so abnormal in these patients that the series was discontinued due to the perceived risk of paraplegia as a result of the angiogram procedure itself. Conclusion: We plan to perform CT angiograms in patients with neuromuscular scoliosis to further elucidate the vascular anatomy in these patients

Despite the expansion of arthroscopic surgery of the shoulder, the open deltopectoral approach to the shoulder is still frequently used, for example in fracture fixation and shoulder replacement. However, it is sometimes accompanied by unexpected bleeding. The cephalic vein is the landmark for the deltopectoral interval, yet its intimate relationship with the deltoid artery, and the anatomical variations in that structure, have not previously been documented. In this study the vascular anatomy encountered during 100 consecutive elective deltopectoral approaches was recorded and the common variants described. Two common variants of the deltoid artery were encountered. In type I (71%) it crosses the interval and tunnels into the deltoid muscle without encountering the cephalic vein. However, in type II (21%) it crosses the interval, reaches the cephalic vein and then runs down, medial to and behind it, giving off several small arterial branches that return back across the interval to the pectoralis major. Several minor variations were also seen (8%). These variations in the deltoid artery have not previously been described and may lead to confusion and unexpected bleeding during this standard anterior surgical approach to the shoulder. Cite this article: Bone Joint J 2013;95-B:657–9

Introduction: Due to the diversity of the prosthetic implants for hip arthroplasty, a better matching between the implant and the intra and extra-medullary characteristic of the patient anatomy is now possible. This adaptation however requires a perfect understanding of the tridimensional characteristics of the patient hip anatomy. Little data are available in the literature. We aimed to analyze the muscular and bony anatomy of the hip at the time of arthroplasty. Material and Methods: data acquisition was performed according a standardized CT-scan in the same center for all patients within the standard workup before arthroplasty. Standardized measurements were obtained after automatic tridimensional bone reconstructions using dedicated software. 549 femurs in 469 patients including primitive coxarthrosis (COX), dysplasic development of the hip (DDH) and aseptic osteonecrosis (ONA) were analyzed. Mean age was 58 and 70% of the patients were women. Tridimensional reconstruction of the muscular anatomy of the hip was performed for 30 patients using manual contouring on dedicated software. Characteristics of the bony and muscular anatomy were then analyzed according to the etiology and correlations between bony and muscular anatomy were evaluated. Results: Concerning the bone analysis, mean offset was 23.2 ±1.5mm in the DDH group, 40.5±1.2 mm in the COX group and 29.6± 0.9mm in the ONA group(p< 0.001). Neck-shaft angle was 132±25º in the DDH group, 130±0.5º in the COX group and 134±1º in the ONA group (p< 0.001). Mean anteversion was 33±3.5º in the DDH group, 25±3.8º in the COX group and 16±3.2º in the ONA group (p< 0.001). Concerning the muscular analysis, gluteus medius and minimus volumes were correlated with the body mass index and with the gender, but not with patient age (p: NS). Location of the muscular insertion of the gluteus medius and minimus on the greater trochanter were correlated with the femoral anteversion. Discussion: The results of our study demonstrated that bony and muscular anatomical characteristics were correlated with the etiology of the degenerative joint disease, with the patient body mass index and gender. Surgeons should be aware of these characteristics to improve the patient anatomy reconstruction during the arthroplasty

Introduction. The aim of this study is to better understand the anatomy of the forefoot to minimise surgical complications following minimally invasive forefoot surgery. Methods. The study examines the plantar anatomy of the lesser toes in ten cadaver feet. The tendons, nerves and bony anatomy are recorded. Results. The anatomy of the flexor tendons reveals the short flexor tendon bifurcates to allow the long flexor tendon to pass through it reliably at the level of the metatarsophalangeal joint (MTPJ) in the lesser rays. The division of the intermetatarsal nerves to digital nerves relative to the MTPJ is more variable. This nerve division is more consistently related to the skin of the web between the toes. In the first webspace the division is on average 3cm proximal to the skin at the deepest part of the cleft. In the second, third and fourth webspaces this distance is reduced to 1cm. The level of the deepest part of the webspace to the MTPJ is also variable. Discussion. Surgical release of the flexor tendons is recommended just proximal to the MTPJ for releasing both tendons and distal to the proximal interphalangeal joint for the long flexor tendon. The webspace skin and MTPJ's are easily identifiable landmarks clinically and radiologically. Awareness of the intermetatarsal nerve division will help to reduce nerve injuries with minimally invasive surgery to the plantar forefoot

Purpose: The anatomy of the endosteal canal of the proximal femur varies greatly in the general population. This variability can compromise total hip arthroplasty when a femoral stem is inserted without cement. While the secondary fixation of the implant is dependent on several parameters, the predominant factor is the primary stability and the large contact between the bone and the treatment surface of the apposed prosthesis. These two conditions, necessary but insufficient to guarantee an excellent clinical result, are obtained if there is a correct bone-implant morphology match. We analysed the morphology of the endosteal canal of the proximal femur to determine whether there is a standard anatomic conformation justifying the use of line prostheses. Material and methods: We examined 30 femurs harvested from 30 individuals in a consecutive series in our anatomy laboratory. We made 12 scanner slices parallel to the knee joint line starting 1 cm above the apex of the lesser trochanter going up to 11 cm above the lesser trochanter. For each slice, we assimilated the canal to an ellipsoid surface to characterise its barycentre, the angle of the greater axis relative to the reference plane of the posterior condyles, and its dimensions defined with length (greater axis), and width (perpendicular to the greater axis). Results: For each femur, the AP projections of the barycentres fell on a straight line (anatomic axis) and the lateral projections on a parabole. Helitorsion, i.e. the difference in the torsion angles between the first slice and the last slice was constant (57±8.5°). The dimensions were recorded for each slice. Discussion: This method can be criticised. We were able to confirm the tridimensional data reported by Noble and confirmed the notion of a somatotype. We defined the normal (statistical) equation of the endosteal canal for the proximal end of the femur (barycentre, dimensions). Conclusion: The anatomy of the endosteal canal of the upper extremity of the femur is not variable but standardised. It is thus possible to adapt the bone to the prosthesis

We studied the anatomy of the patellofemoral joint in the axial plane on cryosections from a cadaver knee and on MR arthrotomograms from 30 patients. The cryosections revealed differences in the geometry and anatomy of the surface of the articular cartilage and corresponding subchondral osseous contours of the patellofemoral joint. On the MR arthrotomograms the surface geometry of the cartilage matched the osseous contour of the patella in only four of the 30 knees. The articular cartilaginous surface of the intercondylar sulcus and corresponding osseous contour of the femoral trochlea matched in only seven knees. Since MR arthrotomography can distinguish between the surface geometry of the articular cartilage and subchondral osseous anatomy of the patellofemoral joint, it allows the surgeon and the radiologist to appraise the true articulating surfaces. We therefore recommend MR arthrotomography as the imaging technique of choice

Introduction. According to the literature, the gait does not return to normal after THA. However, the three-dimensional hip anatomy is usually not assessed before and after surgery. Our hypothesis was that an accurate reconstruction of the hip anatomy, based on a three-dimensional preoperative planning, may normalize the gait after THA. Material and method. 18 consecutive patients, graded Charnley A, aged of 59.3 ±13 years, underwent THA for unilateral primary osteoarthritis using a direct anterior minimal invasive approach. A 3D computerised planning was performed, the implants size and position were chosen in order to restore, the leg length, the off-set, the centre of rotation and the anteversion angles (Figure 1). At 1 year follow up, a 3D gait analysis was performed and included 29 parameters describing the kinetics and the kinematics. Each patient was compared to himself using the contra-lateral healthy hip, as well as to a group of 13 healthy volunteers. Results. The real implants were the same than the ones planned in all the patients. The hip anatomy was restored with a high accuracy: 0.1±3mm for the hip rotation centre, −1.4±3 mm for the leg length and −0.9±3.5mm for the femoral offset. With respect to the gait, there was no significant difference between the operated side and the control-lateral leg. When compared to the control group, all the patients were within the normal range for all the parameters (Figure 2). Discussion and conclusion. The results suggest that the combination of an accurate 3D reconstruction and a direct anterior minimal invasive approach may allow to achieve a normal gait after THA at one year follow up

Recently, gender-specific designs of total knee replacement have been developed to accommodate anatomical differences between males and females. We examined a group of male and female distal femora matched for age and height, to determine if there was a difference in the aspect ratio (mediolateral distance versus anteroposterior distance) and the height of the anterior flange between the genders. The Hamann-Todd Collection provided 1207 skeletally mature cadaver femora. The femoral length, the anteroposterior height, height of the lateral and medial flanges and the mediolateral width were measured in all the specimens. The mechanical axis of the femur, the cut articular width and the aspect ratio were assessed. Statistical analysis of the effect of gender upon the aspect ratio and the lateral and medial flanges was undertaken, controlling for age, height and race. The mean aspect ratio of male femora was 1.21 (. sd. 0.07) and of female femora it was 1.16 (. sd. 0.06) (p < 0.001). There was no significant difference between male and female specimens in the mean size of the lateral flange (6.57 mm (. sd. 2.57) and 7.02 mm (. sd. 2.36), respectively; p = 0.099) or of the medial flange (3.03 mm (. sd. 2.47) and 3.56 mm (. sd. 2.32), respectively; p = 0.67). Future work in the design of knee prostheses should take into account the overall variability of the anatomy of the distal femur

Shoulder Arthroscopy techniques may pose surgical risk to vascular structures that may cause active bleeding during surgery. The vascularity of the subacromial structures showed constant patterns of distribution and specific sources of bleeding were analyzed. Knowledge of the vascular anatomy may decrease the bleeding during subacromial arthroscopy surgery. Shoulder Arthroscopy techniques may pose surgical risk to vascular structures that may cause active bleeding during surgery. A detailed anatomy map of frequent sources of bleeding is more than desired in order to properly identify these bleeding points, and avoid the unnecessary overuse of thermal tools and pressure pumps to control the hemorrhage. Our purpose is to study the vascular anatomy of the subacromial space, and to map the major sources of expected bleeding during subacromial arthroscopy surgery. Ten shoulders of five adult cadavers underwent whole body arterial perfusion with a mixture of lead oxide, gelatin and water. The shoulders were dissected, photographed, tissue specimens were radio graphed, scanned and analyzed with a digital software analyzer. Careful dissection of the different arteries of the subacromial bursa, and anatomic landmarks of the walls were documented. Correlations of bleeding areas during subacromial arthroscopic surgery and cadaver dissection were carried out. A vascular map of the bursa was created. The vascularity of the subacromial structures showed constant patterns of distribution and specific sources of bleeding were analyzed. We divided this space into walls with their major arteries as follows: Anterior wall: Acromial branch of the thoracoacromial artery. Posterior wall: Acromial branch of the suprascapular artery. Medial wall: Anterior and posterior Arteries of the AC joint. Lateral wall: No major arteries identified. Vascularity of the roof and floor is also described. The subacromial space is highly vascular. Knowledge of the vascular anatomy may decrease the bleeding during subacromial arthroscopy surgery

Introduction: morphological analysis of the general shape of the bones and of their particular variations according to the patient age, gender and pathology is an important step to improve the orthopedic management. We aimed to performed a gender specific analysis of the bi and tridimensional anatomy of the distal femur in vitro and in vivo. Materials and Methods: in vitro data were obtained from CT-scan performed on 92 dry men femurs and 52 dry women femurs. Using a manual contouring method and a segmentation method, tridimensional reconstructions were obtained and according to two different algorithms, the regions of discrepancies between men and women were determined. An automatic calculation of 59 defined measurements was then performed. In vivo data providing from 59 CT-scans of men femur and 73 CT-scan of women femurs were acquired. Standardized bidimensional measurements at the level of the trochlear cut were performed. Results: in vivo, statistically significant differences were observed for the: medio-lateral distance (M-Ld women=7.4±0.4cm vs M-Ld men=8.4±0.5cm; p< 0.0001), anteroposterior distance (A-Pd women=5.9±0,4cm vs A-Pd men= 6.4±0.4cm; p< 0.0001) and for the ratio anterior-posterior distance/medio-lateral distance (p< 0.0001). The trochlear groove angle was comparable in the two groups. In vitro, the tridimensional shape of the distal femur was more trapezoidal in women than in men. Medio-lateral distances were also statistically greater in men than in women (p< 0.01), the ratio anterior-posterior distance/medio-lateral distance was also statistically greater in men than in women (p< 0.01) and the Q angle more open in women than in men (p< 0.01). Discussion: Three types of differences between men and women were observed in this gender specific evaluation of the distal femur anatomy. First, for a same anteroposterior distance, the medio-lateral distance was smaller in women. Second, the global shape of the distal femur was more trapezoidal in women and third the Q angle was more open in women. This gender specific anatomy should be clinically considered when performing total knee arthroplasty in women and gender specific implants may be required

Introduction: The importance of isolated gastrocnemius contracture in disorders of the foot and ankle has been established in recent years. The aim of this study is to describe the proximal anatomical approach to the medial and lateral heads of gastrocnemius and to compare the sizes of the medial and lateral heads of the gastrocnemius. Method: 15 cadaveric knees were dissected using a posterior approach 1cm below the level of the skin crease. Proximity of cutaneous nerves and major vessels was noted. The heads of the gastrocnemius were dissected from their origin and the cross sectional anatomy was defined. Results: Approach to the medial head of gastrocnemius is safe. Conversely the variable anatomy of the nerves in the approach to the lateral head means that extreme care must be taken if complications are to be avoided. The aponeurosis of the medial head of gastrocnemius was 2.4 times the cross-sectional area compared to the lateral head. Conclusion: In this study we describe a safe posterior approach to the medial aponeurosis of gastrocnemius and also describe the different sizes of the medial and lateral gastrocnemius heads. We propose that the release of the medial head alone is safe and likely to be efficacious in the surgical treatment of isolated gastrocnemius tightness that has failed non-operative treatment

The effect of rheumatoid arthritis on the anatomy of the cervical spine has not been clearly documented. We studied 129 female patients, 90 with rheumatoid arthritis and 39 with other pathologies (the control group). There were 21 patients in the control group with a diagnosis of cervical spondylotic myelopathy, and 18 with ossification of the posterior longitudinal ligament. All had plain lateral radiographs taken of the cervical spine as well as a reconstructed CT scan. The axial diameter of the width of the pedicle, the thickness of the lateral mass, the height of the isthmus and internal height were measured. The transverse diameter of the transverse foramen (d1) and that of the spinal canal (d2) were measured, and the ratio d1/d2 calculated. The width of the pedicles and the thickness of the lateral masses were significantly less in patients with rheumatoid arthritis than in those with other pathologies. The area of the transverse foramina in patients with rheumatoid arthritis was significantly greater than that in the other patients. The ratio of d1 to d2 was not significantly different. A high-riding vertebral artery was noted in 33.9% of the patients with rheumatoid arthritis and in 7.7% of those with other pathologies. This difference was statistically significant. In the rheumatoid group there was a significant correlation between isthmus height and vertical subluxation and between internal height and vertical subluxation

In this case report a four-year-old girl with ulnar dimelia is described. She had six digits without mirror symmetry in her right hand. The first pre-axial digit was excised and true pollicisation performed for the second pre-axial digit. The arterial anatomy was abnormal but there was not symmetrical development of the arterial tree

Purpose:. To determine the insertion of the different layers of the rotator cuff and apply it to rotator cuff tears. Anatomical insertion of the rotator cuff holds the key to a proper anatomical repair. Method:. A study of the rotator cuff insertion was done in conjunction with MSc student department Anatomy. The rotator cuff consists of a capsular and tendinous layer. They have different mechanical properties. The capsular layer inserts ± 3 mm more medially on the tuberosity and the tendinous layer more laterally. It was shown that the superficial layer extends beyond the greater tuberosity and connects the supra-spinatus tendon to the sub-scapularis tendon via the bicepital groove. This connection was called the “rotator hood”. The “rotator hood” has a mechanically advantageous insertion, is a strong structure with a compressive force on the proximal humerus. Conclusion:. 1. The rotator cuff inserts on the greater tuberosity as two separate entities. 2. The capsular layer inserts on the more medial 2–3 mm. 3. The tendinous layer is attached over a broader more lateral area giving it a mechanical advantage. 4. The tendinous layer of supra-spinatus extends beyond the tuberosity to connect to the sub-scapularis tendon providing an even greater mechanical advantage

Acetabular bone structure is not the same in all patients and can be defined by the radiolucent triangle superior to the acetabulum. We ask if the acetabular anatomy determines the initial cup fixation and screws use. We have assessed 205 hips in which a Cerafit cementless cup was implanted. According to Dorr et al., acetabulae were classified as type A, in which the radiolucent triangle had an isosceles shape (86 hips), type B, in which the triangle extended into the teardrop (90 hips), and type C which had a right-angle triangle (29 hips). The use of screws was decided at the time of surgery and according to cup stability, not acetabular anatomy. Avascular necrosis and inflammatory arthritis were the most frequent diagnoses in type A hips, osteoarthritis in type B, and dysplasia in type C. Women were more frequent in types A and C (p< 0.001). The use of screws was more frequent in women (p< 0.001) and in type A (34.9%) and type C hips (62.1%) than in type B hips (20.0%) (p< 0.001). The multivariate logistic regression model showed the acetabular type (p=0.11) and gender (p=0.003) as independent factors. Acetabular types A (OR=1.98, 95% CI: 0.922–4.208, p=0.075) and C (OR=5.09, 95% CI: 1.74–14.9, p=0.003) increase the risk for screw use. Men have a lower risk for screw use (OR=0.329, 95% CI: 0.16–0.68, p=0.003). Acetabular anatomy and gender determine the use of screws in cementless cups. Continued follow-up is necessary to determine if screws results in less loosening and osteolysis

A good understanding of musculoskeletal pathologies not only requires a good knowledge of normal human anatomy but also an insight in human evolution and development. Biomechanical studies of the musculoskeletal system have greatly improved our understanding of the human musculoskeletal system via medical imaging, modeling and simulation techniques. The same techniques are, however, also used in the study of nonhuman species and a comparison of human and nonhuman data can yield interesting insight in form-function relationships and mechanical constraints on motion. Anatomical and biomechanical studies on dogs and rabbits have already yielded valuable insight in disease mechanisms and development of musculoskeletal pathologies such as osteoarthritis (OA). Nonhuman primates have, however, rarely been studied in this context, though they may prove particularly valuable as they can provide us with an evolutionary context of modern human anatomy and pathology. The high prevalence of osteoarthritis in modern humans and its rare occurrence in wild primates has previously been explained as due to human joints being ‘underutilized’ or ‘underdesigned’. Modern humans are highly specialized for bipedalism, while nonhuman primates typically use a wide range of locomotor modes and joint postures to travel through the three-dimensionally complex forest canopy. These hypotheses can, however, be challenged, as it seems more likely that the low occurrence of OA in wild primates is due to a combination of underreporting of the disease and absence of the ageing effect in these species. Our understanding of musculoskeletal function and disease in modern humans would clearly benefit from more studies investigating the occurrence and characteristics of OA in nonhuman primates

Humeral head size is defined by the radius of curvature and the thickness of the articular segment. This ratio of radius to thickness is within a narrow range with an average of 0.71. The articular surface of the normal humeral head measured within the AP plane is defined by three landmarks on the non-articular surface of the proximal humerus. The perfect circle concept can be applied for assessment of the anatomic reconstruction of the post-operative x-rays and more importantly can be used intra-operatively as a guide when choosing the proper prosthetic humeral head component. The humeral head is an elliptical shape with its AP dimension being approximately 2 mm less than the SI dimension. This shape contributes to the roll and translation of the normal shoulder but is not replicated by the spherical shape of the prosthetic humeral head. The glenoid vault has a consistent 3D shape and use of the vault model within 3D planning software can define the patient's pre-morbid anatomy, specifically the location of the joint line and patient specific version and inclination. Use of this tool can assist the surgeon in defining the optimal implant and its location. In patients with little or no bone loss, a symmetric glenoid implant is often ideal for resurfacing. When there is asymmetric bone loss, often seen posteriorly with osteoarthritis, an asymmetric posteriorly augmented component can improve the ability to correct the deformity while maintaining the native joint line. It is suggested that these augmented implants in selected patients will help restore and maintain humeral alignment and lessen the risk for residual posterior humeral head subluxation and eccentric loading of the glenoid component

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

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

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

Purpose. The purpose of this study was to determine whether intra-operative identification of osseous ridge anatomy (lateral intercondylar “residents” ridge and lateral bifurcate ridge) could be used to reliably define and reconstruct individuals' native femoral ACL attachments in both single-bundle (SB) and double-bundle (DB) cases. Methods. Pre-and Post-operative 3D, surface rendered, CT reconstructions of the lateral intercondylar notch were obtained for 15 patients undergoing ACL reconstruction (11 Single bundle, 4 Double-bundle or Isolated bundle augmentations). Morphology of native ACL femoral attachment was defined from ridge anatomy on the pre-operative scans. Centre's of the ACL attachment, AM and PL bundles were recorded using the Bernard grid and Amis' circle methods. During reconstruction soft tissue was carefully removed from the lateral notch wall with RF coblation to preserve and visualise osseous ridge anatomy. For SB reconstructions the femoral tunnel was sited centrally on the lateral bifurcate ridge, equidistant between the lateral intercondylar ridge and posterior cartilage margin. For DB reconstructions tunnels were located either side of the bifurcate ridge, leaving a 2mm bony bridge. Post-operative 3D CTs were obtained within 6 weeks post-op to correlate tunnel positions with pre-op native morphology. Results. Pre-op native ACL attachment site morphology was very similar to previous in-vitro studies: the mean centre was found at 27% along Blumensaat's line (range 19-33%) and 38% the width of the lateral femoral condyle (range 31-43%). Despite the variability between individuals there was close correlation between pre-operative localization of the femoral attachment centre and position of single bundle ACL reconstructions tunnels on the post-op CT (R=0.92). Similar results were observed for double-bundle and isolated bundle augment reconstructions. Conclusion. ACL attachment site morphology varies between individuals. Intra-operative localization of the osseous landmarks (lateral intercondylar and bifurcate ridges) appears to lead to accurate, individualised anatomical tunnel placement whether using single or double-bundle reconstruction techniques

Various classifications of scaphoid fractures have been based on plain radiography, but there are difficulties in defining the actual fracture line without an appreciation of the three-dimensional anatomy. Radiological fracture lines were therefore mapped on transparent methylmethacrylate models of the bone. An analysis of 91 acute fractures showed that 11 were apparently incomplete. The other 80 showed three basic anatomical patterns: transverse through the waist, oblique in the plane of the dorsal sulcus, or of the proximal pole. There was some variation and comminution in these patterns, but no distal fractures of the body were seen. The interpretation of different radiological projections is discussed. The findings have implications for the management and the assessment of outcome

Problem-based learning medical courses are now in the majority in the UK. This type of teaching, based on research by Barrow in the 1960s, seeks to integrate basic sciences and clinical teaching, leading to the acquisition of an integrated knowledge base that is readily recalled and applied to the analysis and solution of problems. We noticed an apparent difference in the core anatomical knowledge in a group of 4th year medical students during their orthopaedic placement, some of whom had been taught a traditional course and some a PBL course. We set out to quantify this difference. 60 simple anatomy questions were asked, with 30 minutes allowed, and no negative marking. 33 students were PBL taught, and 27 by a traditional course, with a roughly equal male: female ratio. The average score in the PBL group was 39.2% (range 11–52%), whereas the traditional group averaged 73.7% (range 63–79%). A second study was undertaken on two groups of 80 second year medical students, at 2 different UK universities with comparable teaching standards and entry requirements, both being well-established courses. Again, a simple 50-question anatomy paper was used, without negative marking. The traditional course students scored a mean of 37.5 (25–46), and the PBL group scored a mean of 32.3 (18–45). The results were statistically significant (p< 0.0001). Our results suggest that the difference between the two groups with regard to core anatomical knowledge increases with progression through training. This has significant implications due to PBL courses being in the majority. During the usually short orthopaedic attachment, it will become increasingly difficult for clinicians to teach effectively due to the lack of this knowledge

We carried out a cadaver study of 16 iliolumbar veins in order to define the surgical anatomy. Two variants were found; a single vein at a mean distance of 3.74 cm from the inferior vena cava (11 of 16) and two separate draining veins at a mean distance from the vena cava of 2.98 cm for the proximal and 6.24 cm for the distal stem (5 of 16). Consistently, the proximal vein tore on attempted medial retraction of the great vessels. The mean length of the vein was 1.6 cm and its mean width 1.07 cm. Three stems were shorter than 0.5 cm. Two or more tributaries usually drained the iliacus and psoas muscles, and the fifth lumbar vertebral body. The obturator nerve crossed all veins superficially at a mean of 2.76 cm lateral to the mouth. In four of these, this distance was less than 1.5 cm. Usually, the lumbosacral trunk crossed deep, at a mean distance of 2.5 cm lateral to the mouth, but in three veins, this distance was 1 cm or less. Our findings emphasise the need for proper dissection of the iliolumbar vein before ligature during exposure of the anterior lumbar spine

Correct positioning of the femoral component in resurfacing hip arthroplasty (RHA) is an important factor in successful long-term patient outcomes. Computer-assisted navigation (CAS) shows potential to improve implant positioning and possibly prolong survivorship in total hip and knee arthroplasty. The purposes of CAS systems in resurfacing the femoral head are to insert the femoral head and neck guide wire with greater accuracy and to help in sizing the femoral component, thus reducing the risk of notching of the head and neck junction. Several recent studies reported satisfactory precision and accuracy of CAS in RHA. However, there is little evidence that computer navigation is useful in the presence of anatomical deformities of the proximal femur, which is frequently observed in young patients with secondary degenerative joint disease. The purpose of this in-vitro study was to determine the accuracy of an image-free resurfacing hip arthroplasty navigation system in the presence of two femoral deformities: pistol grip deformity of the head and femoral neck junction and slipped upper femoral epiphysis deformity. An artificial phantom leg with a simulated hip and knee joint was constructed from machined aluminum. Implant-shaft angles for the guide wire of the femoral component reamer were calculated, in frontal and lateral planes, with both a computer navigation system and an electronic caliper combined with micro-CT. With normal anatomy we found close agreement between the CAS system and our measurement system. However, there was a consistent disagreement in both the frontal and lateral planes for the pistol grip deformity. Close agreement was found only on the frontal plane angle calculation in the presence of the slipped upper femoral epiphysis deformity, but calculation of the femoral head size was inaccurate. This is the first study designed to assess the accuracy of a femoral navigation system for resurfacing hip arthroplasty in the presence of severe anatomical deformity of the proximal femur. Our data suggests CAS technology should not be used to expand the range of utilisation of resurfacing surgery, but rather to improve the surgical outcome in those with suitable anatomy

The restoration of pain-free stable function in gleno-humeral arthritic cases in various situations such as rotator cuff deficiency, old trauma and failed total shoulder arthroplasty is a challenging clinical dilemma. The Bayley-Walker shoulder has been designed specifically for very difficult cases where surface replacement devices do not provide sufficient stability. This device is a fixed-fulcrum reversed anatomy prosthesis consisting of a titanium glenoid component with a CoCrMo alloy head that articulates with an UHMWPE liner encased in a titanium alloy humeral component that has a long tapered grooved stem. The centre of rotation of the Bayley-Walker shoulder is placed medially and distally with respect to the normal shoulder in order to improve the efficiency of the abductor muscles. An important problem in devices of this type is obtaining secure and long-lasting fixation of the glenoid component. The glenoid component relies on fixation through the cortical bone by using threads, which protrude through the anterior surface of the scapula at the vault of the glenoid. It is HA coated for subsequent osseointegration. The purpose of this study was to investigate fixation of the glenoid component. A 3D finite element model of the glenoid component implanted in a scapula was analysed using Abaqus. The implant was placed in position in the scapula, with the final 2–3 screw threads cutting through the cortical bone on the anterior side at the vault of the glenoid due to the anatomy in this region. The analysis was performed for two load cases at 60° and 90° abduction. A histological study of a retrieval case, obtained 121 days after implantation, was also conducted. The FEA results showed that most of the forces were transmitted from the component to the cortical bone of the scapula, the remaining load being transmitted through cancellous bone. In particular the area where the threads of the glenoid component penetrated the scapula showed high strain energy densities. Histology from the retrieved case showed evidence of bone remodelling whereby new bone growth resulting in cortical remodelling had occurred around the threads. Both the FEA and histological study show that fixing the component at multiple locations in cortical bone may overcome the problems of glenoid loosening associated with constrained devices. The Bayley-Walker device has been used on a custom basis since 1994; 81 Bayley–Walker shoulders for non-tumour conditions and 43 Bayley-Walker glenoid components have been used in association with a bone tumour implant, with good early results. Radiographically, radiolucencies have not been observed and overall the comparisons with the original Kessel design are positive

Purpose. Intramedullary fixation of clavicle fractures requires an adequate medullary canal to accommodate the fixation device used. This computer tomography anatomical study of the clavicle and its medullary canal describes its general anatomy and provides the incidence of anatomical variations of the medullary canal that complicates intramedullary fixation of midshaft fractures. Methods. Four hundred and eighteen clavicles in 209 patients were examined using computer tomography imaging. The length and curvatures of the clavicles were measured as well as the height and width of the clavicle and its canal at various pre-determined points. The start and end of the medullary canal from the sternal and acromial ends of the clavicle were determined. The data was grouped according to age, gender and lateralization. Results. The average length of the clavicle was 151.15mm with the average sternal and acromial curvature being 146° and 133° respectively. The medullary canal starts on average 6.59mm from the sternal end and ends 19.56mm from the acromial end with the average height and width of the canal at the middle third being 5.61mm and 6.63mm respectively. Conclusion. The medullary canal of the clavicle is large enough to accommodate commonly used intramedullary devices in the majority of cases. The medullary canal extends far enough medially and laterally to ensure that an intramedullary device can be passed far enough medially and laterally past the fracture site to ensure stable fixation in most middle third clavicle fractures. An alternative surgical option should be available in theatre when treating females as the medullary canal is too small to pass an intramedullary device past the fracture site on rare occasions. Fractures located within 40mm of the lateral or medial ends of the clavicle should not be treated by intramedullary fixation as adequate stability is unlikely to be achieved. MULTIPLE DISCLOSURES

The primary source for the blood supply of the head of the femur is the deep branch of the medial femoral circumflex artery (MFCA). In posterior approaches to the hip and pelvis the short external rotators are often divided. This can damage the deep branch and interfere with perfusion of the head. We describe the anatomy of the MFCA and its branches based on dissections of 24 cadaver hips after injection of neoprene-latex into the femoral or internal iliac arteries. The course of the deep branch of the MFCA was constant in its extracapsular segment. In all cases there was a trochanteric branch at the proximal border of quadratus femoris spreading on to the lateral aspect of the greater trochanter. This branch marks the level of the tendon of obturator externus, which is crossed posteriorly by the deep branch of the MFCA. As the deep branch travels superiorly, it crosses anterior to the conjoint tendon of gemellus inferior, obturator internus and gemellus superior. It then perforates the joint capsule at the level of gemellus superior. In its intracapsular segment it runs along the posterosuperior aspect of the neck of the femur dividing into two to four subsynovial retinacular vessels. We demonstrated that obturator externus protected the deep branch of the MFCA from being disrupted or stretched during dislocation of the hip in any direction after serial release of all other soft-tissue attachments of the proximal femur, including a complete circumferential capsulotomy. Precise knowledge of the extracapsular anatomy of the MFCA and its surrounding structures will help to avoid iatrogenic avascular necrosis of the head of the femur in reconstructive surgery of the hip and fixation of acetabular fractures through the posterior approach