The quadrate tubercle is a small

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

found upon the upper part of the

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates wit ...

. It serves as a point of insertion of the

quadratus femoris muscle The quadratus femoris is a flat, quadrilateral skeletal muscle. Located on the posterior side of the hip joint, it is a strong external rotator and adductor of the thigh, but also acts to stabilize the femoral head in the acetabulum. Quadratu ...

, along with the

intertrochanteric crest The intertrochanteric crest is a prominent bony ridge upon the posterior surface of the femur at the junction of the neck and the shaft of the femur. It extends between the greater trochanter superiorly, and the lesser trochanter inferiorly. Ana ...

and the

linea quadrata A slight ridge is sometimes seen commencing about the middle of the intertrochanteric crest, and reaching vertically downward for about 5 cm. along the back part of the body: it is called the linea quadrata (or quadrate line), and gives attach ...

Structure

The quadrate

is located about the junction of the upper one-third and lower two-thirds, on the

. In a small anatomical study, it was shown that the epiphysial line passes directly through the quadrate tubercle. The quadrate tubercle is the site of insertion of the quadratus femoris muscle.

Variation

The size of the quadrate tubercle varies. It is not always located on the intertrochanteric crest. Adjacent areas can also be part of the quadrate tubercle, such as the posterior surface of the greater trochanter or the neck of the femur.

Additional images

Sobo 1909 141 Quadrate tubercle Arabic YM.png, Right femur. Posterior surface. (Quadratus femoris and Quadrate tubercle labeled.)

References

Bones of the lower limb Femur {{musculoskeletal-stub