Humérus

Definition

The humérus is a Os even and asymmetrical of the Upper limb human. It constitutes the skeleton of the arm. It is a long bone, therefore made up of a Diaphyse and two épiphyse S.

Situation

The humérus articulates:

in top, inside and behind with the cavity glénoïdale of the Scapula by its head.
in bottom with the bones of the Front armlever via the pallet humérale:

in bottom and outwards with the Radius by the capitulum huméral.
in bottom and inside with the Ulna by trochlée the humérale.

Orientation

Spherical surface in top and inside, the most projecting edge ahead. General anatomical form

triangular Os with the cut to the 1/3 means of its diaphyse, one describes 3 faces and 3 edges to him:

posterior face, antéro-side face, face antéro-médiale.
former edge, edge médial, side edge.

Head of 30 mm ray accounting for 1/3 of sphere.
Angle cervico-diaphysaire of 130°.
Pallet humérale buckled of 30 with 45° forwards.
Angle of retroversion of the head humérale of 20° compared to the pallet humérale.
Angle of the head compared to the horizontal one: 45°.

Palpable reference marks

major tuber
minor tuber
side épicondyle and médial
furrow inter tubérositaire.

Reports/ratios

Nerve axillaire (C5-C6), radial (C6-C7-C8-Th1), ulnar (C8-Th1)
Arteries axillaire and humérale deep
Tendon long portion of the biceps and transverse ligament huméral.

Private clinic

Fracture on the level of the collars: lesion of the nerve axillaire (More abduction of the shoulder to the top of 8°)
Fracture to the 1/3 means of the diaphyse: lesion of the radial nerve (hand in swan neck) and lesion of the deep artery humérale.
Fracture of the épicondyle médial: lesion of the ulnar nerve (cubital claw)
Ignition of synovial of the tendon of the long portion of the biceps: ténosynovite
Luxation of the scapulo-humérale: control nerve axillaire to carry out
Luxation acromio-claviculaire: rupture of the ligaments perished & para-articular

Anatomy

Its higher end presents a head, delimited by the anatomical collar , a major tuber (or trochiter), external, and a minor tuber (trochin), former. This higher end is separated from the Diaphyse humérale by the surgical collar .

With its former face, the diaphyse is marked of two peaks which prolong the two tubers of the higher end, delimiting the furrow intertuberculaire (or gutter intertubérositaire). The peak of the major tuber is prolonged along the diaphyse to form its former edge. The posterior face of the diaphyse is cross obliquely by the furrow of the radial Nerf (directed in bottom and outwards).

The lower end comprises two condyles, a médial and side. The side condyle comprises a side épicondyle making following the side peak supra-condylaire, and the capitulum (or condyle huméral), articular with the radial head . The condyle médial comprises a épicondyle médial (or épitrochlée) making following the peak supra-condylaire médiale, and trochlée the, articular one with the Ulna. The posterior face of the lower end of the humérus is bored by the pit olécrânienne.

Pathology

Fractures of the higher end

Their great frequency at the old subject as well as the proximity of the articular complex of the shoulder put in danger the function of the upper limb. They can be associated with a Luxation gléno-humérale.

Surgical collar: zone with the union of the épiphyse and the diaphyse, zone of weakness, at the risk of fracture.

Fracture diaphysaire

It is frequent but the functional after-effects are rare, except in the case of an attack of the radial Nerf.

Fractures of the lower end

See Elbow.

Humérus : osteology and reports/ratios

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