Elbow stability after simple elbow dislocation
- PDF / 572,941 Bytes
- 6 Pages / 595 x 792 pts Page_size
- 75 Downloads / 215 Views
Original Contribution Obere Extremität https://doi.org/10.1007/s11678-020-00609-6 Received: 2 September 2020 Accepted: 1 October 2020 © The Author(s) 2020
Jana Willin · Jonas Schmalzl · Lars Lehmann · Christian Gerhardt Klinik für Unfall- und Handchirurgie, ViDia Kliniken Karlsruhe, Karlsruhe, Germany
Elbow stability after simple elbow dislocation Preliminary results following nonoperative vs. surgical ligamentous repair
Background Dislocation of the elbow is the second most common joint dislocation in adults [24]. The most common cause is a fall on the outstretched arm. The elbow is circumferentially stabilized by bony, ligamentous, and muscular structures that can be divided into primary and secondary static and dynamic stabilizers [16]. The ulnohumeral joint with the coronoid process as anterior resistance to dislocation and the medial and lateral collateral ligament complex are termed “primary stabilizers.” The radiohumeral joint as a static structure and the common extensor and flexor–pronator tendons as dynamic structures are the secondary stabilizers of the elbow joint [17]. Although several potential mechanisms have been postulated, the course and the location of the injury that will lead to a dislocation are still the subject of debate. The most widely recognized mechanism, described by O’Driscoll et al., is called the “horri-circle” constituting a valgus external rotation theory [18]. During a fall on the outstretched arm, the elbow begins to flex immediately upon hand impact with the ground. Due to an axial compression of the ulnohumeral joint with internal rotation of the body on the elbow, a supination force occurs. While the loading axis is shifted laterally, a valgus force is created. These forces cause the ligament structures to tear, starting with the lateral ulnar collateral ligament, resulting in posterolateral rotational instability. O’Driscoll et al. differentiated between
three stages, ranging from a ligament tear (stage 1) to a grossly unstable elbow (stage 3c). The other postulated theory is based on a valgus force with hyperextension of the elbow [23]. The hyperextension of the elbow with disruption of the medial collateral ligament leads to a dissociation of the coronoid process from the laterally sloping surface of the medial part of the trochlea. This leverage converts the forces to a combination of lateral rotation and valgus strain allowing the radial head to move posteriorly leading to a posterolateral dislocation of the elbow. A simple dislocation was defined by Josefsson et al. as dislocation without relevant accompanying fractures or bony injuries and minimal periarticular avulsions smaller than 2–3 mm [10]. Therefore, by definition the osseous stability is not compromised in simple dislocation. Still, due to the wide-ranging appearance with a large distribution of soft tissue damage, the term “simple” can lead to underestimating the injury. To call these dislocations “ligamentous dislocation” might therefore be more expedient. Besides the ligaments, the common extensors and the flexor
Data Loading...
