In the skeleton of humans and other animals, a tubercle, tuberosity or apophysis is a Tubercle that serves as an attachment for . The muscles attach by , where the enthesis is the connective tissue between the tendon and bone.
Main tubercles
Humerus
The
humerus has two tubercles, the
greater tubercle and the
lesser tubercle. These are situated at the proximal end of the bone, that is the end that connects with the
scapula. The greater/lesser tubercule is located from the top of the
acromion laterally and inferiorly.
Radius
The radius has two, the radial tuberosity and Lister's tubercle.
Ribs
On a
rib cage, tubercle is an eminence on the back surface, at the junction between the neck and the body of the rib. It consists of an articular and a non-articular area. The lower and more medial articular area is a small oval surface for articulation with the transverse process of the lower of the two vertebrae which gives attachment to the head. The higher, non-articular area is a rough elevation which gives attachment to the ligament of the tubercle. The tubercle is much more prominent in the upper ribs than in the lower ribs.
Tibia
The most prominent tubercle of the
tibia, a leg bone which is more commonly known as the shinbone or shankbone, is the tibial tuberosity. The tibial tuberosity is located on the tibia's
anterior surface, distal to the medial condyle. It creates a bony prominence just below the
patella, and can be easily located with the fingers. It creates an attachment point for the
knee, or patellar ligament. Other tubercles of the tibia include the medial intercondylar tubercle, the lateral intercondylar tubercle, and Gerdy's tubercle.
Femur
A
trochanter is one of up to three tubercles of the
femur:
-
Greater trochanter
-
Lesser trochanter
-
Third trochanter, which is occasionally present
Fifth metatarsal
In the
fifth metatarsal bone, the most proximal part of the bone is termed the "tuberosity", and the secondary ossification center that is normally present thereon in children is termed the "apophysis".
Related diseases and conditions
Fractures
The main type of fracture affecting tubercles is avulsion fracture, by pulling the attached tendon.
Apophysitis
Apophysitis is an
inflammation of a tubercle. It mainly affects growing children, with overuse of the affected tubercle.
Examples include:
-
Osgood–Schlatter disease (apophysitis of the tibial tubercle)
[
]
-
Sever's disease (apophysitis of the posterior tubercle of the heel)
-
Sinding-Larsen and Johansson syndrome (apophysitis of the inferior pole of the patella)
Enthesitis
Enthesitis is an anatomically close but separate condition, wherein there is inflammation of the
entheses, the sites where tendons or ligaments insert into the bone.
It is associated with HLA B27 arthropathies such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis.
