Distal humeral fracture

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Classification according to ICD-10
S42.4 Fracture of the proximal end of the humerus
S42.40 Part unspecified
S42.41 Supracondylar
S42.42 Lateral epicondyle
S42.43 Medial epicondyle
S42.44 Epicondylus, epicondyli, unspecified; Distal epiphysis
S42.45 Transcondylar (T or Y shape)
S42.49 Other and multiple parts; Trochlea
ICD-10 online (WHO version 2019)

Distal humeral fractures are fractures of the lower end of the humerus . They occur in children by falling on the outstretched arm and in adults by falling on the elbow joint .

Occurrence and classification

The fractures are rare in adults and account for only 3% of all bone injuries and 17–30% of all elbow injuries (Josten, Lill).

In children , supracondylar humeral fractures occur more frequently between the ages of 5 and 10 years and account for 5% of all child fractures, but 80% of all child elbow fractures. The cause is usually a fall from a height while exercising or during leisure time. The non-dominant arm is more often affected. In children, the cubitus varus malalignment due to inadequate fracture treatment is particularly common, the surgical correction of which is often difficult and complex.

Adults

For clinical purposes it is sufficient to distinguish between metaphyseal, extra-articular (supracondylar) and intra-articular (percondylar) fracture forms. No further classification has proven itself in the long term. The usual x-rays in two planes are sufficient for diagnosis and operation planning.

treatment

The vast majority of distal humeral fractures require surgical treatment. Some metaphyseal fractures may be treated conservatively (with plaster cast or Sarmiento bowls); The spiral course of the nearby radial nerve calls for caution.

Metaphyseal fractures

Fractures in the lower, metaphyseal quarter of the humerus are rare and almost exclusively affect adults. They are difficult to treat because the lower fracture end is too short for retrograde intramedullary nails and important nerves are adjacent. The medial plate fixation is little known, but elegant. The patient lies on his back, the surgeon sits in front of the inside of the upper arm. Unlike the radial nerve, the ulnar nerve does not cross the surgical area, but rather runs parallel to the shaft into the ulnar sulcus . If it is exposed and held backwards, one has complete freedom for fragment reduction and osteosynthesis.

Supracondylar fractures

In supracondylar humeral fractures, the cartilage-related joint roll is intact, but broken off from the lower end of the shaft.

In adults, cortical fracture fragments are usually found, so that Kirschner wires do not guarantee adequate protection of the fracture. That is why osteosynthesis with plates on both sides makes sense. Unilateral plate restorations are exceptionally possible with angle-stable plates if at least two screws can be accommodated in the epicondyle .

Percondylar fractures

In adults, percondylar fractures mean that the trochlea humeri with the epicondyles is not only separated from the shaft, but also broken in on itself, in two or more parts.

Surgical treatment is complex: the ulnar nerve has to be exposed, the olecranon has to be sawn through and folded up with the triceps brachii muscle . The condyle roll is reconstructed like a three-dimensional puzzle and held together with Kirschner wires and small-fragment cannulated screws. The connection to the shaft (stable during exercise) is re-established with one-third tube or reconstruction plates on both sides. Anatomically pre-formed angle-stable plates (Mayo) are well suited, but expensive. The olecranon is reattached with a tension strap .

In view of the complex anatomy of the lower end of the humerus, a humerus model should be set aside during the reconstruction.

Childish fractures

Supracondylar fractures are classified by Gartland as:

  • Type I undislocated
  • Type II partial tilting with preserved dorsal cortex
  • Type III complete dislocation without cortical contact

A distinction must be made between diacondylar fractures and percondylar fractures in the condyle or, depending on age, in the radial or ulnar epicondyle. There is a risk of confusion with the bone cores that are typically isolated from the age.

therapy

Gartland types I and II are treated conservatively with an upper arm cast without any rotational errors. For all other types, surgically in the form of a closed reduction and fixation with two crossed Kirschner wires under image intensifier control.

In percondylar fractures, one epicondyle (usually the one on the spoke side) has broken off. Two thin Kirschner wires are sufficient for fixation.

The position of the fragments and wires is difficult to assess, especially in young children, because larger parts of the skeleton are not yet ossified, but rather cartilaginous and therefore radiolucent. If necessary, sonography or magnetic resonance imaging can help . Even if the reduction is successful, there is a risk of developing a malalignment in the elbow joint (cubitus varus) because the relevant part of the growth plate is damaged.

Anesthesia and storage

Humeral fractures close to the elbow should always be operated on with the patient in intubation anesthesia and in the prone position. The splayed upper arm must be placed on a radiolucent support or a (padded) wooden board inserted through it.

photos

  • Osteosynthesis of a distal humerus fracture

  • Tension band of the olecranon

literature

Guidelines

Individual evidence

  1. ↑ a b F. Hefti: Pediatric orthopedics in practice . Springer, 1998, ISBN 3-540-61480-X .
  2. ^ Nicolas F. Barbier, Solange De Wouters, Sidi Yaya Traore, Khanh Tran Duy, Pierre-Louis Docquier: Patient specific instrumentation for corrective osteotomy in case of posttraumatic cubitus varus in children Acta Orthopædica Belgica 2019, Volume 85, Issue 3 from September 2019 , Pages 297-304
  3. ^ JJ Gartland: Management of supracondylar fractures of the humerus in children. In: Surg Gynecol Obstet. 109, 1959, pp. 145-154.