Isolate and irreducible radial head dislocation in children: a rare case of capsular interposition

  • PDF / 1,214,754 Bytes
  • 5 Pages / 595.276 x 790.866 pts Page_size
  • 56 Downloads / 171 Views

DOWNLOAD

REPORT


(2020) 21:659

CASE REPORT

Open Access

Isolate and irreducible radial head dislocation in children: a rare case of capsular interposition Luigi Tarallo* , Michele Novi, Giuseppe Porcellini and Fabio Catani

Abstract Background: Radial head dislocation with no associated lesions, is a relatively uncommon injury in children. In this case report, it is reported a case of anteromedial locked radial head dislocation in children, and we discuss its clinical presentation and pathogenetic mechanism of injury. Case presentation: An 8-year-old girl fell off on her right forearm with her right elbow extended in hyperpronation. An isolated radio-capitellar dislocation was identified with no other fractures or neurovascular injuries associated. Elbow presented an extension-flexion arc limited (0°- 90°), and the prono-supination during general anesthesia shows “a sling effect” from maximal pronation (+ 55°) and supination (+ 90°) to neutral position of forearm. The radial head dislocation was impossible to reduce and an open reduction was performed using lateral Kocher approach. The radial head was found “button-holed” through the anterior capsule. The lateral soft tissues were severely disrupted and the annular ligament was not identifiable. Only by cutting the lateral bundle of the capsule was possible to reduce the joint. At 50 moths follow-up, patient presented a complete Range of motion (ROM), complete functionality and no discomfort or instability even during sport activities. Discussion and conclusion: It is important to understand the pathogenic mechanisms of locked radial head dislocation in children. Some mechanism described are the distal biceps tendon or the brachialis tendon interposition. However even the anterior capsule can hinder reduction. A characteristic “sling-effect” of the forearm could be pathognomonic for capsular button-holing. Surgical release of the capsular bundle sometimes is the only way to reduce the dislocation and obtain a good outcome. Keywords: Locked radial head dislocation, Children elbow dislocation, Capsular button-holed

Background Radial head dislocation rarely occurs in patients younger than 8 years old, (peak incidence of elbow dislocation is 12–13 years of age) and it is often associated with ulna fracture such as a Monteggia injury or plastic deformation injuries described as Monteggia-variant [1, 2]. The radial head subluxation (“pulled elbow” or “nursemaid elbow”) however is a common traumatic condition in pediatric * Correspondence: [email protected] Orthopedics and Traumatology Department, University of Modena and Reggio Emilia, Policlinico di Modena, Modena Via del Pozzo 71, 41124 Modena, Italy

population, that mainly occurs in children between 1 and 4 years of age and it can generally be reduced with forced flexion of the elbow associated with full supination. If the anterolateral radial head dislocation is common, on the other hand a true radio-capitellar dislocation is a relatively uncommon injury in children. Often, anterior radiocapitellar dislocations may occur a