Distal humeral fractures
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
The distal humerus can be considered as a divergent two column structure supporting the distal articular surface. The distal humeral shaft is triangular shaped in cross-section with its apex directed anteriorly. The medial column diverges approximately 45 degrees from the shaft in the coronal plane, whereas the lateral column diverges at approximately 20 degrees from the shaft.2 The trochlea connects the columns centrally and forms an articulation with the coronoid and olecranon facets of the ulna. The anatomy of the trochlea is analogous to that of a spool. The capitellum is the distal-most portion of the lateral column, which articulates with the radial head. The trochlea is more distal than the capitellum in the coronal plane, which results in a valgus alignment of 4–8 degrees. The distal articular segment of the humerus is internally rotated 3–8 degrees relative to the epicondyles and has 30–40 degrees of anterior angulation relative to the central axis of the humerus.12 The distal posterior portion of the lateral column is non-articular and permits distal placement of contoured posterolateral plates (Figure 23.1).
Paediatric upper limb trauma
Sebastian Dawson-Bowling, Pramod Achan, Timothy Briggs, Manoj Ramachandran, Stephen Key, Daud Chou in Orthopaedic Trauma, 2014
Supracondylar fractures are classified into extension-type (∼98 per cent; Fig. 24.4) and flexion-type (∼2 per cent). This chapter concentrates on extension-type injuries (Fig. 24.4). Type I – Non-displaced or minimally displaced (<2 mm). Intact anterior humeral line. These fractures are typically stable because of an intact circumferential periosteum.Type II – Displaced (> 2 mm) with an intact posterior cortex. The anterior humeral line passes anterior to the middle of the capitellum as the distal fragment is angulated posteriorly. The posterior periosteum remains intact, but hinged. Rotational deformity suggests more significant injury with medial/lateral column impaction/comminution.Type III – Significantly displaced with no cortical contact. The distal fragment lies posteromedially (type IIIA, more common) or posterolaterally (type IIIB), with extensive periosteal disruption. Extension in the sagittal plane is usually accompanied by rotation in the coronal and/or axial planes. Medial or lateral column comminution predisposes to coronal plane malalignment and malrotation. There is a higher incidence of soft tissue and neurovascular injuries.
Distal humerus fractures in the elderly
Peter V. Giannoudis, Thomas A. Einhorn in Surgical and Medical Treatment of Osteoporosis, 2020
Several classification systems have been described for fractures of the distal humerus. The OA/OTA system is composed of three main groups with a total of nine subtypes (10). A-type fractures are extra-articular, B-type fractures are partial articular, and C-type fractures are complete articular injuries. Further subclassification is based on the amount of intra- or extra-articular comminution. In our experience, this classification system is most useful for discussion of fractures only when used in a very broad sense such as A-type, B-type, and C-type fractures. Mehne and Jupiter (11) described seven types of bicolumnar distal humerus fractures: high T, low T, Y fractures, H fracture, medial and lateral lambda fractures, and multiplane fractures. Coronal sheer fractures are not well described by the previous classification systems. Bryan and Morrey described coronal sheer fractures in 1985 (12), and this classification was modified by McKee in 1996 (13). The first type of fracture, also known as a Hahn-Steinthal fracture, is a coronal fracture of the capitellum. An osteochondral lesion of the capitellum, also known as a Kocher-Lorenz fracture, is the second type. The third type is a comminuted fracture of the capitellum, and the fourth type has extension of the capitellar fracture into the trochlea.
High elasticity of the flexor carpi ulnaris and pronator teres muscles is associated with medial elbow injuries in youth baseball players
Published in The Physician and Sportsmedicine, 2022
Akira Saito, Kyoji Okada, Kazuyuki Shibata, Hiromichi Sato, Tetsuaki Kamada
From 2017 to 2019, a total of 231 male youth baseball players from local baseball clubs in Japan participated in this cross-sectional study. All participants were recruited through community-based advertisements prior to the beginning of the spring season. Inclusion criteria were being a baseball player aged 9–12 years. Exclusion criteria were (1) diagnosis of osteochondritis dissecans of the humeral capitellum, (2) a history of elbow surgery, (3) a previous shoulder injury or shoulder pain, and (4) a history of throwing within 24 hours prior to measurement. Before the examination, the participants completed a questionnaire regarding their personal data (age, height, weight, dominant arm), months of experience of baseball, baseball position, and practice time per week. The sample size was calculated using a statistical software (G*Power version 3.1.9.2, Dusseldorf, Germany). Given the study design (different between two independent means), the effect size = 0.5 (medium), α-error < 0.05, a desired power (1-β error) = 0.8, and allocation ratio = 2, the total sample size resulted in 144 participants (group 1 = 48 participants and group 2 = 96 participants, respectively).
9 years’ follow-up of 168 pin-fixed supracondylar humerus fractures in children
Published in Acta Orthopaedica, 2018
Noora Tuomilehto, Antti Sommarhem, Aarno Y Nietosvaara
Mean subjective score for appearance was 8.7 (2–10) and for function 9.0 (2–10) according to the 168 answered questionnaires (Table 1). Fracture type, patient’s sex, and AHL in relation to capitulum did not affect the results. Mean functional scores were lower either in the 31 patients who were older than 10 years at the time of fracture (8.4, p = 0.01) and/or in the 29/36 patients who had nerve injuries (8.6, p = 0.05). Mean subjective scores for appearance were lower in the 14 patients who had had open reduction (7.8, p = 0.03) and in 9 patients who had BA values exceeding normal values by 10˚ (7.1, p = 0.02) (Figure 3, see Supplementary data). Open reduction patients’ AHL crossed the capitulum in 11/12 and BA was within 10˚ of the normal range in 11/12 cases. One or both subjective scores of 13 (8%) patients were below 6. 8 of these patients attended a control visit, and 5 of 8 had asymmetry of elbow ROM or CA or both of more than 10˚ (p = 0.002). 11 of these 13 patients were operated by a registrar (alone 5, under supervision 6) (p = 0.4).
A custom-made distal humerus plate fabricated by selective laser melting
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Thansita Thomrungpiyathan, Suriya Luenam, Boonrat Lohwongwatana, Winai Sirichativapee, Kriengkrai Nabudda, Chedtha Puncreobutr
Computational simulations were performed with a compression load of 200 N in axial direction on the distal end of humerus bone (Sabalic et al. 2013; Kudo et al. 2016). Note that the load is also in a testing range to evaluate load bearing in primary rehabilitation (Varady et al. 2017). As shown in Figure 2, the load was applied on surfaces of capitellum and trochlea in all models. The proximal end of humerus bone, include greater tubercle, lesser tubercle and intertubercular groove was defined as fixed support. As suggested in previous study (Bogataj et al. 2015), bolt pretension load of 10 N was also applied to all screws. Two types of contact conditions were defined. Contact interactions that allow finite sliding with zero friction coefficient (no separation constraint) were defined between the bone and the plates as well as between the screws and plate. Bonded contact constraint was applied between the screws and the surrounding bone as well as between the cortical bone and the trabecular bone.
Related Knowledge Centers
- Adaptation
- Ontogeny
- Humerus
- Head of Radius
- Trochlea of Humerus