This clinical procedural photograph demonstrates the point-of-care ultrasound (POCUS) technique for diagnosing a 'pulled elbow' (radial head subluxation) in a pediatric patient. The child is positioned supine on a medical examination table with the head turned laterally. A medical professional is seen applying a high-frequency linear ultrasound transducer to the posterior-lateral aspect of the patient's elbow joint. The probe is oriented caudally to visualize the radiohumeral joint and the annular ligament. In the background, an ultrasound monitor displays a real-time grayscale musculoskeletal image. This procedure is used in pediatric emergency medicine to identify signs such as an increased distance between the radial head and the humerus capitate or the interposition of the annular ligament, which confirms subluxation. The image illustrates proper hand placement for stabilizing the young patient's limb while manipulating the transducer to achieve diagnostic views.

This diagnostic image is a lateral X-ray of a human elbow joint following procedural reduction of a radial head dislocation and elbow subluxation. The radiograph demonstrates restored anatomical alignment: the radial head is congruent with the humeral capitellum, and the ulnohumeral articulation appears well-positioned. No obvious cortical fractures or avulsion fragments are visible in the distal humerus, proximal radius, or ulna. A red arrow points to a subtle, localized area of increased radiopacity within the anterior joint space, suggestive of joint effusion or hemarthrosis. This finding is characterized by a density that is higher than the surrounding soft tissue but significantly lower than the adjacent cortical bone. The image serves as an educational example of post-reduction radiological assessment in emergency orthopedics, highlighting successful joint realignment and secondary signs of intra-articular trauma such as hemarthrosis.

Diagnostic imaging series of the right elbow demonstrating an anteromedial fracture-dislocation of the radial head. Panels (a-c) present volume-rendered 3D CT reconstructions in anterior oblique and anteroposterior views, highlighting a comminuted radial head fracture involving approximately 25% of the articular surface. Small osseous fragments are visible wedged posterior to the radial head and within the radial notch of the ulna. Rotatory subluxation is indicated by the malalignment of the ulnar trochlear notch relative to the humeral trochlea. Panels (d-e) show axial CT slices, and (f-g) show sagittal slices in soft tissue windows. These cross-sectional images identify the brachialis tendon (white arrows) as a linear hyperdensity traversing posterolateral to the radial head fracture site. This anatomical relationship is clinically significant as it illustrates a soft tissue 'sling' effect that can impede manual reduction of the dislocation. The content is suitable for orthopedic and radiology education focusing on complex elbow trauma and the identification of mechanical blocks to reduction.

This diagnostic image is a lateral X-ray radiograph of the elbow joint. It demonstrates significant musculoskeletal pathology involving the proximal forearm and distal humerus. The primary finding is a radial head dislocation, where the radial head is displaced anteriorly and is no longer articulating with the capitellum of the humerus. This misalignment is indicated by a red arrow pointing toward the displaced radial head. Additionally, the image shows signs of elbow subluxation, characterized by an incongruous relationship between the trochlear notch of the ulna and the trochlea of the humerus, suggesting partial loss of contact between the joint surfaces. Key anatomical landmarks visible include the distal humeral epicondyles, the olecranon process, and the coronoid process of the ulna. There is no evidence of an acute fracture in this projection. This radiographic study is clinically significant for diagnosing complex elbow injuries and assessing the need for orthopedic reduction. It serves as an educational example of traumatic joint disruption for students and clinicians in emergency medicine and orthopedics.

This composite educational graphic details the intraosseous arterial blood supply of the femoral head through anatomical diagrams and microscopic vascular casts. The main illustration labels the key nutrient vessels: Superior (SRA), Inferior (IRA), and Anterior (ARA) Retinacular Arteries, which transition into Superior (SEA), Inferior (IEA), and Anterior (AEA) Epiphyseal Arteries. The graphic identifies three distinct patterns of arterial anastomosis within the femoral head epiphysis: 1. Superior-inferior Epiphyseal artery anastomosis (57%), 2. Inferior-anterior Epiphyseal artery anastomosis (30%), and 3. Uniform anastomosis (13%). Each variation is represented by a schematic illustrating the dominant arterial loops and a corresponding high-magnification photograph of a microscopic vessel cast, showing the intricate, three-dimensional network of small vessels (≥0.05 mm). This visualization highlights the redundancy of the femoral head's blood supply, which is critical for understanding the pathophysiology of femoral neck fractures and avascular necrosis.

This figure showcases a human tibia specimen prepared using an advanced vascular casting and bone-clearing technique to demonstrate internal intraosseous blood supply. Figures a (rear view), b (side view), and c (front view) display the physical specimen where the cortical bone has been replaced with a transparent epoxy resin. Inside the clear diaphysis, the intraosseous vascular network is clearly visible, highlighted by a red casting agent. The network shows the primary nutrient artery entering the medullary cavity and bifurcating into ascending and descending medullary trunks with subsequent terminal branching toward the proximal and distal metaphyses. The arrangement reveals higher vessel density at the epiphyses compared to the mid-shaft. Figure d provides a complementary 3D digital model of the same tibia, illustrating the external anatomical landmarks and surface morphology used for resin mold construction. This anatomical demonstration is crucial for orthopedic surgical planning, particularly in understanding bone vascularization and nutrient foramen localization.

Plain Radiography of a long bone diaphysis demonstrates an aggressive, ill-defined osteolytic lesion with cortical destruction and periosteal reaction. The radiograph shows a moth-eaten destruction pattern with diffuse bone loss extending along a substantial portion of the shaft. Periosteal elevation produces Codman triangle in the swept cortex, while layered deposition of reactive new bone beneath the periosteum can create an onion-skin appearance; in some cases perpendicular radiating spicules or sunburst-like projections may be seen. The lesion often breaches the cortex or expands to form a soft tissue mass that extends beyond the bone. Although ultrasound or CT can delineate the soft tissue component, CT and MRI best characterize the extent, relation to surrounding structures, and marrow involvement. The radiographic pattern is highly suggestive of an aggressive small round blue cell tumor, most notably Ewing sarcoma, particularly in children and adolescents. Differential considerations include osteosarcoma, osteomyelitis, lymphoma, metastasis, or eosinophilic granuloma, but the combination of an diaphyseal, permeative lesion with onion-skin periosteal reaction strongly favors Ewing. Clinical correlation with pain, fever, raised inflammatory markers, and prompt biopsy is essential to confirm diagnosis and guide treatment, which typically combines chemotherapy, limb-sparing surgery, and possibly radiotherapy.

This composite of three 3D surface-rendered models (A, B, and C) illustrates the spatial relationship between bone macrostructure and microvasculature, likely in a mammalian femur model. Panel A shows an undecalcified bone model displaying the cortical shaft, marrow cavity, and trabecular network in the metaphysis. A central medullary artery (arrow) is visible running longitudinally. Panel B depicts the vascular cast alone after decalcification, highlighting the nutrient artery, its primary branches, and a dense network of sinusoid capillaries within the metaphysis. External arrows point to the periosteal arteries and branched peripheral networks. Panel C demonstrates the over-imposition of both models, utilizing pseudo-coloring to differentiate the calcified bone matrix (lighter gray) from the internal and external vascular systems (darker gray). The imaging modality is micro-computed tomography (µCT) with vascular contrast agents, designed to study bone-vessel interactions, such as those occurring in normal physiology or pathological states like metastasis or osteolysis. The visualization highlights anatomical regions including the diaphysis, metaphysis, and epiphysis.

This clinical photograph captures an intraoperative view of an open reduction and internal fixation (ORIF) of a humeral fracture. The surgical site is prepared with blue sterile drapes and accessed via an anterolateral Henry’s approach. Several metallic surgical retractors (including Hohmann-style and right-angle retractors) are positioned to maintain visualization of the surgical field by retracting the biceps and brachialis muscles. A stainless steel orthopedic locking compression plate (LCP) or limited contact dynamic compression plate (LC-DCP) is shown positioned over the anterolateral surface of the humerus. Several screw holes are visible in the plate, with some already occupied by cortical or locking screws to stabilize the bone fragments. The image demonstrates the critical steps of alignment and hardware placement in orthopedic trauma surgery. Visible landmarks include the flexed elbow with skin markings and the deep exposure of the humeral shaft, emphasizing the relationship between the implant and the underlying musculoskeletal anatomy.

A clinical photograph of an orthopedic surgical implant: a Locking Compression Plate (LCP) designed for the superior anterior clavicle, manufactured using Electron Beam Melting (EBM) 3D printing technology from Ti-6Al-4V titanium alloy. The plate exhibits a contoured, elongated, and slightly curved morphology to match the anatomical shape of the clavicle. The proximal end (left) features a widened head with multiple small, circular locking screw holes. The distal shaft (right) contains three larger, oval-shaped dynamic compression apertures. The surface texture is notably granular and matte, characteristic of the additive manufacturing process, with visible rough edges and surface irregularities likely due to partially melted powder particles. This specimen demonstrates the application of patient-specific additive manufacturing in orthopedic trauma surgery to enhance implant strength and fit compared to traditional forged or cast plates.

A series of clinical photographs and hardware images demonstrating orthopedic internal fixation. Panels (A) and (B) show the structural design of two 9-hole orthopedic plates: a Locking Compression Plate (LCP) with combination holes allowing for both locking and compression screws, and a Limited Contact Dynamic Compression Plate (LC-DCP) with uniform oblong holes designed to reduce bone-to-plate contact and protect periosteal blood supply. Panels (C) through (F) depict the surgical application of these plates on a femur using the Minimally Invasive Percutaneous Plate Osteosynthesis (MIPPO) technique. The images show small skin incisions, the insertion of the plates along the bone shaft using surgical forceps, and the subsequent fixation with screws through these limited portals. This visual material illustrates the comparative surgical approach and hardware characteristics used in veterinary orthopedic surgery, specifically focusing on femoral fracture management and the biological advantages of minimally invasive plate osteosynthesis over traditional open reduction.

This comparison photograph illustrates the pre-operative planning and contouring of an orthopedic osteosynthesis plate using a patient-specific 3D-printed anatomical model. The images show a side-by-side 'before' and 'after' view of a metallic 3.5-mm locking compression plate (LCP) being adapted for acromial fixation. The plate features a series of Combi holes, designed for both angle-stable locking screws and dynamic compression cortical screws. In the left frame, the distal clavicle reconstruction plate is positioned relatively flat against the white 3D-printed model of the acromion. In the right frame, following manual contouring with plate benders, the plate exhibits a distinct anterior curvature. This adjustment is designed to lift the anterior acromion, correcting for down-sloping to prevent subacromial impingement on the rotator cuff. The use of 3D printing in this context demonstrates advanced surgical planning for complex orthopedic anatomy where standard pre-contoured plates are unavailable.

Anatomical Diagram of the Knee Extensor Mechanism. This schematic illustration depicts a surgical approach for repairing the patellar tendon or quadriceps tendon, particularly in the context of chronic ruptures. The diagram features a central circular patella situated between the proximal quadriceps muscle and the distal tibia/fibula. Surgical markings are indicated by six black dots: three positioned at the superior pole of the patella and three at the inferior pole. These dots are connected by three longitudinal dashed lines—one central and two paracentral—representing transosseous tunnels or suture pathways designed to secure the tendon to the bone. Proximal to the patella, a series of horizontal lines represents the quadriceps muscle, potentially indicating a V-Y advancement or lengthening procedure (Codivilla technique). The illustration serves as an educational guide for orthopedic surgical planning in patients with complex extensor mechanism injuries, such as those associated with systemic comorbidities like tertiary hyperparathyroidism.

This intraoperative clinical photograph displays an open surgical reconstruction of the extensor mechanism of the knee. The surgical field reveals the anterior aspect of the knee with the patella centrally located. The image captures the 'framing' technique using a semitendinosus tendon autograft or allograft. Two distinct tendon strands are visible, having been passed through the vastus medialis and vastus lateralis muscles superiorly. These strands are then brought down and sutured to each other and around the prepatellar rim to reinforce the patellar tendon reconstruction. Interrupted sutures are visible along the graft strands, securing them to the underlying quadriceps and patellar structures. The distal portion of the graft is seen extending toward the tibial tuberosity. This procedure is typically indicated for chronic patellar tendon ruptures or cases with poor tissue quality, aiming to restore active knee extension and stable patellar tracking.

This lateral view X-ray of the knee demonstrates the anatomical alignment of the distal femur, proximal tibia, and patella. The primary clinical focus is on the patellofemoral compartment, where evidence of prior orthopedic surgical intervention for quadriceps tendon reconstruction is visible. Four radiopaque suture anchors (TWINFIX) are identifiable as dense, metallic-density markers embedded within the superior aspect of the patellar bone. Faint, linear radiopacities extending from these anchors represent high-strength non-absorbable suture material used to secure the quadriceps tendon. The joint space between the femoral condyles and the tibial plateau appears preserved, and the tibial tuberosity is clearly visible on the anterior proximal tibia. This image serves as a clinical example of postoperative hardware placement for extensor mechanism repair in the knee, highlighting the use of suture anchors for soft-tissue-to-bone fixation.

This musculoskeletal model illustrates the biomechanics of the knee joint, specifically focusing on the extensor mechanism. The anatomical diagram features a schematic 3D rendering of the distal femur, proximal tibia, fibula, and patella. Red cylindrical vectors represent the Hill-type musculotendon units of the quadriceps femoris. These muscle representations originate superiorly and converge to insert onto the superior aspect of the patella. A single red vector extends from the inferior pole of the patella to the tibial tuberosity, representing the patellar ligament. The model demonstrates the patella's role as a fulcrum or frictionless pulley, transmitting forces from the quadriceps to the tibia to facilitate knee extension. A prosthetic spacer or tibial component is visible between the femoral condyles and the tibial plateau, suggesting the model is configured for post-operative orthopedic analysis or total knee arthroplasty (TKA) simulation. This visualization is used in biomechanical engineering to estimate joint contact forces and limb dynamics.

This set of clinical photographs shows a detailed anatomical dissection of a Type IV quadriceps femoris complex from a left-sided human specimen. Four views are provided: wide anterior (a), enlarged anterior (b), wide posterior (c), and enlarged posterior (d). The images demonstrate the multi-layered and multi-headed structure of the quadriceps tendon. Key anatomical structures labeled include the rectus femoris (RF), vastus medialis (VM), and three distinct parts of the vastus lateralis: superficial (SVL), intermediate (IVL), and deep (DVL). The vastus intermedius (VI) is shown in the central deep layer. Notably, the specimen illustrates accessory heads numbered 5, 6, and 7, highlighting the morphological variability of the muscle. A common tendon (CT) serves as a fusion point for the fifth and sixth heads. The distal attachment site includes the patella (P) and patellar tendon (PT). This educational visual is intended for advanced musculoskeletal anatomy and surgical planning, illustrating the complex stratification and tendinous architecture of the knee extensors.

This clinical photograph displays a macro-dissection of the distal human extensor apparatus of the knee, highlighting the complex multi-layered architecture of the quadriceps muscle group. The image identifies the muscle bellies and aponeurotic insertions of the vastus lateralis, vastus medialis, rectus femoris, and vastus intermedius. Notably, it demonstrates the tensor vastus intermedius and its aponeurotic tendon, characterizing the five-component model of the quadriceps. The rectus femoris is medially reflected to reveal the insertion of the vastus medialis into both the rectus femoris and the vastus intermedius. The vastus lateralis shows distinct aponeurotic fiber strands and a strong muscle belly inserting at the supero-lateral semi-circle of the patella (indicated by a red dotted line). In contrast, the vastus medialis occupies the supero-medial half of the patella's upper semi-circle (indicated by a blue dotted line). Fiber orientations for the lateral components are directed toward the medial femoral condyle, illustrating the dynamic balance required for patellar tracking and knee extension stability.

This composite educational material consists of two T1-weighted magnetic resonance (MR) images demonstrating musculoskeletal anatomy and biomechanical measurements of the lower limb. Image A is an axial MR cross-section of the mid-thigh, featuring manually segmented green outlines of the four quadriceps femoris muscles: the Rectus Femoris (RF) located anteriorly, the Vastus Lateralis (VL) laterally, the Vastus Medialis (VM) medially, and the Vastus Intermedius (VI) situated centrally and deep, surrounding the femur. This view is utilized for calculating anatomical cross-sectional area (ACSA) and muscle volume. Image B is a sagittal MR image of the knee joint illustrating the biomechanical concept of the patellar tendon moment arm (PTMA). The PTMA is visually defined as the perpendicular distance (white line) between the patellar tendon's line of action (yellow line A) and the tibiofemoral contact point (TFCP, marked by a red dot at point B). This measurement is critical for assessing the mechanical advantage of the quadriceps during knee extension. Both images serve as primary diagnostic and research tools in sports medicine and orthopedics for evaluating muscle architecture and joint mechanics.

A multi-panel clinical imaging series documenting the progression and surgical management of a complex hip injury. (a) 3D reconstructed CT scan of the pelvis showing a comminuted posterior wall acetabular fracture with associated posterior hip dislocation. (b) 3D CT reconstruction demonstrating postoperative internal fixation using a curved metallic plate and screws along the posterior acetabular rim. (c) Coronal 2D CT slice showing osteosynthesis failure, characterized by hardware displacement, loss of reduction, and superior subluxation of the femoral head. (d) Anteroposterior (AP) pelvic radiograph following salvage surgery, illustrating a cemented total hip arthroplasty (THA). The radiopacity of the prosthetic femoral stem, acetabular cup, and cerclage wiring is clearly visible. The series illustrates the clinical transition from primary Open Reduction Internal Fixation (ORIF) failure to secondary arthroplasty in orthopaedic trauma management.

This diagnostic image consists of two 3D-reconstructed CT scan views of a left hip joint following a manual reduction procedure. The imaging depicts the anatomical relationship between the proximal femur and the pelvis. Key findings include a fracture of the posterior wall of the acetabulum with a visible bone fragment. Furthermore, an impaction injury or depression is present on the posterior-superior aspect of the femoral head, characteristic of damage sustained during a posterior hip dislocation. The reconstruction allows for assessment of joint congruity and the integrity of the acetabular rim. The clinical significance of these findings relates to orthopedic stability, where the combination of a posterior wall defect and femoral head impaction (analogous to a Hill-Sachs lesion in the shoulder) increases the risk of recurrent dislocation. This material is suitable for orthopedic surgical planning and educational review of traumatic hip injuries.

This diagnostic image is a 3D reconstruction from a Computed Tomography (CT) scan focusing on the left hip joint. It demonstrates a posterior redislocation of the hip, characterized by the femoral head being completely displaced outside of its anatomical position within the acetabulum. Significant pathology is visible at the articulation site, specifically an impaction injury where the posterior margin of the acetabulum has created a distinct depression or 'indentation' in the posterior aspect of the femoral head. There is also evidence of cortical irregularity and fragmentation at the posterior acetabular wall, consistent with a posterior wall fracture. The proximal femur and pelvic structures (ilium and ischium) are clearly visualized, illustrating the severe loss of joint congruity. This image serves as a clinical example of traumatic hip instability and the associated bony complications, such as impaction fractures, that can occur during recurrent dislocation events in orthopedic surgery and trauma medicine.