Bones and joints
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings in McMinn’s Concise Human Anatomy, 2017
Carpal bones - bones of the wrist. The eight small carpal bones each have their own characteristic sizes and shapes, details of which need not be learned. The important point is to remember the order of the bones in the two rows of four from the lateral to the medial side: in the proximal row, the scaphoid, lunate, triquetral and pisiform bones; and in the distal row, the trapezium, trapezoid, capitate and hamate bones. The scaphoid, lunate and triquetral bones articulate with the distal radius, forming the wrist joint (Fig.4.15). The most important carpal bones are the scaphoid (most commonly fractured) and the lunate (most commonly dislocated). The trapezium and the base of the first metacarpal make the carpometacarpal joint of the thumb the most important of the carpometacarpal joints.
Orthopaedic Emergencies
Anthony FT Brown, Michael D Cadogan in Emergency Medicine, 2020
Always X-ray to distinguish a stable from an unstable injury. Stable injuries include transverse shaft and greenstick fractures.Unstable injuries include oblique shaft and comminuted fractures, and the fracture–dislocation of the base of the thumb (Bennett's fracture).Bennett's fracturethis is an oblique fracture through the base of the thumb metacarpal involving the joint with the trapezium, with subluxation of the rest of the thumb radiallylook for swelling of the thenar eminence, sometimes with local palmar bruisingmake sure the X-ray includes the base of the thumb to avoid missing this injury.
Carpal fractures and dislocations
Charles M Court-Brown, Margaret M McQueen, Marc F Swiontkowski, David Ring, Susan M Friedman, Andrew D Duckworth in Musculoskeletal Trauma in the Elderly, 2016
Avulsion triquetral fractures account for over 90% of all triquetral injuries (Figure 27.7). Cast immobilization for approximately 1 month is used for isolated lunate fractures as non-union is rare.154,155 Good or excellent results are reported following the non-operative management of non-displaced or minimally displaced trapezium89,156,157 and hamate fractures.135,158,159
Displaced isolated coronal shearing fracture of the trapezoid: a case report
Published in Case Reports in Plastic Surgery and Hand Surgery, 2021
Yuya Otake, Koji Sukegawa, Kenji Onuma, Shuhei Machida, Riyo Iida, Masashi Takaso
We scheduled an operation with a dorsal approach, four days after the injury. We made a 3 cm longitudinal incision directly over the trapezoid. The trapezoid was exposed, but the fracture site could not be identified dorsally, and reduction could not be be achieved by traction on the fingers and compression of the dorsal bone fragment. Therefore, we severed the second metacarpal-trapezoid ligament and trapezium-trapezoid ligament, and exposed the proximal surface of the second carpometacarpal (CM) joint. The dorsal fragment was identified and inverted to remove the intraarticular hematoma, small bone fragments, and granulation tissue (Figure 3(A)). Thereafter, reduction could be achieved by pushing the dorsal bone fragment to align with the volar fragment, and guide pins were inserted. We assessed the reduction by direct inspection of the proximal joint surface of the second CM joint and confirmed it under fluoroscopy (Figure 3(B,C)). The correct trajectory of the guide pin was also established under fluoroscopy (Figure 3(C,D)) before insertion of a headless compression screw (DTJ mini screw; Meira Co., Ltd., Nagoya, Japan; width proximal 3.4 mm, distal 2.7 mm, length 20 mm). After satisfactory fixation of the fracture, the dissected second metacarpal-trapezoid ligament and trapezium-trapezoid ligament and capsule were repaired. Kirschner wires were used to reduce the pressure on the trapezoid (Figure 4). Rehabilitation of the fingers was initiated immediately postoperatively. The Kirschner wires were removed after two weeks, and range-of-motion exercises were started.
A voxel-based method for designing a numerical biomechanical model patient-specific with an anatomical functional approach adapted to additive manufacturing
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Augustin Lerebours, Frederic Marin, Salima Bouvier, Christophe Egles, Alain-Charles Masquelet, Alain Rassineux
To test the configurability and the universality of the designed model we used four healthy trapezium bones removed from two diseased patients (males aged 61 and 66, left and right trapeziums). The bones were provided by the Académie Nationale de Chirurgie in Paris, and any evidence of pathology was reported by the surgeon. Specimens were stripped of cartilage and soft tissue, dried by immersion in acetone and underwent a fat-removal procedure. All the specimens were scanned with a clinical computed tomography (CT) (slice thickness of 0.625 mm and pixel size of 0.328 mm × 0.328 mm). Manual segmentation (3D Slicer® (Slicer.4.8)), with a threshold value suitable for extracting cortical bone (CT-AAA2: 129.54), was applied prior to the 3D reconstruction using discrete marching cubes with no iterations of smoothing (Lorensen and Cline 1987). 3D models were exported as STL files. The left trapeziums were mirrored, and all were scaled in order to make the distance between the center of the second metacarpal and the scaphoid contact surfaces correspond to an average value (16.846 mm).
Cross-sectional changes of the distal carpal tunnel with simulated carpal bone rotation
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Carpal bone mobilization is a therapeutic technique where the carpal bones are manipulated through multidirectional glide or distraction at the radiocarpal and midcarpal joint. When used in conjunction with wrist splinting, these techniques have shown improvement in carpal tunnel syndrome symptom severity (Huisstede et al. 2010). Previous studies suggest that physical methods which apply forces at or near the carpal bones may serve to decompress the median nerve by increasing the CAA (Marquardt et al. 2015) or total CSA (Bueno-Gracia, Pérez-Bellmunt, et al., 2018; Bueno-Gracia, Ruiz-de-Escudero-Zapico, et al. 2018). The results of this study support these previous findings which show how carpal bone motion can increase the carpal tunnel space near the median nerve. Additionally, the results of this study suggest that carpal bone mobilization techniques which induce inward rotation of the hamate and trapezium may act to increase the CAA, thus relieving the pressure at the median nerve and alleviating the associated carpal tunnel syndrome symptoms.
Related Knowledge Centers
- Carpal Tunnel
- First Metacarpal Bone
- Hand
- Homology
- Scaphoid Bone
- Trapezoid Bone
- Carpal Bones
- Radius
- Metacarpal Bones
- Thumb