159
The ilium is large, flat, slightly curved, and direct- ed upwards. The pubis and ischium lie inferiorly, the pubis more anteromedially, and the ischium more posterolaterally. The obturator foramen is a large aperture in the hip bone between the pubis and ischium. The ilium, ischium, and pubis meet at a narrow, thick central part which has the acetabular fossa for articulation with the head of the femur. The pubis and ischium are fused to- gether by a bar of bone, inferior to the obturator foramen. This is the ischiopubic ramus and
CHAPTER 13
The front and medial side of the thigh
Tubercle of iliac crest Anterior gluteal line
Posterior gluteal line
Posterior superior iliac spine
Posterior inferior iliac spine Greater sciatic notch
Ischial spine Lesser sciatic notch Groove for obturator externus
Ischial tuberosity
Ramus of ischium Acetabular notch
Obturator foramen Inferior pubic ramus
Body of pubis Pubic tubercle Superior pubic ramus Fossa
Lunate surface
Anterior inferior iliac spine Inferior gluteal line
Anterior superior iliac spine
of acetabulum
Fig. 13.1 Right hip bone seen from the lateral side.
Introduction
Before starting to dissect, study the surface anat- omy of the region on yourself or on another liv- ing subject, and relate this to the appropriate dried bones.
160
The front and medial side of the thigh
it is covered by the spermatic cord. Lateral to the pubic tubercle, a resilient band can be felt in the inguinal groove between the anterior surface of the thigh and the abdomen. This is the ingui- nal ligament. On the bone, note a sharp ridge which curves posterolaterally on the superior ra- mus of the pubis from the pubic tubercle to the iliopubic eminence. This is the pecten pubis.
Fibres of the inguinal ligament stretch posteri- orly to the pecten and form the lacunar liga- ment. Below and behind the pubic symphysis, the two inferior pubic rami diverge to form the pubic arch. Each inferior pubic ramus unites with the corresponding ramus of the ischium to form the ischiopubic ramus. The ischiopubic ramus forms the boundary between the thigh and perineum, and is palpable through its length.
Find the iliac crest at the lower margin of the waist. Trace it forwards. It slopes downwards and slightly medially to end in a rounded knob—the anterior superior iliac spine. This may be grasped between the finger and thumb in a thin individual. The inguinal ligament stretches from this spine to the pubic tubercle. On the bone, a is formed by the union of the inferior ramus
of the pubis and the ramus of the ischium.
In the region of the acetabulum, the ilium fuses with the superior ramus of the pubis at the iliopu- bic eminence [Fig. 13.2], and with the ischium at the rough ridge on the posterior surface of the acetabulum.
The greater sciatic notch is a deep, curved depression, or notch, on the posterior margin of the ilium, immediately above the acetabulum. The medial aspect of the ischium has a shallow lesser sciatic notch, separated from the greater sciatic notch by the spine of the ischium. Immediate- ly inferior to the lesser sciatic notch, the ischium expands to form the ischial tuberosity.
The body of the pubis [Fig. 13.1] articulates with its fellow of the opposite side through a me- dian fibrous joint—the pubic symphysis. The pubic symphysis may be felt at the lower end of the abdominal wall. Draw your finger laterally from the pubic symphysis on the anterosuperior surface of the body of the pubis. This surface is the pubic crest which ends in a small, blunt prominence—the pubic tubercle—laterally.
The tubercle is less easily felt in the male, because
Iliac crest
Iliac fossa
Anterior superior iliac spine
Anterior inferior iliac spine Linea terminalis
Iliopubic eminence
Superior pubic ramus Pecten pubis Pubic tubercle
Pubic crest
Symphysial surface
Inferior pubic ramus
Obturator foramen Ischial ramus
Ischial tuberosity, falciform margin Lesser sciatic notch Ischial spine Obturator groove Greater sciatic notch
Posterior inferior iliac spine Posterior superior iliac spine Iliac tuberosity
Auricular area for sacrum
Fig. 13.2 Right hip bone seen from the medial side.
mebooksfree.com
161
Introduction
the acetabular fossa give attachment to the lig- ament of the head of the femur. This liga- ment contains connective tissue and small blood vessels, covered by a synovial membrane and at- tached on the femur to the non-articular pit of the head of the femur. The ligament of the head of the femur may transmit some small blood vessels through foramina in the pit to the head of the femur.
The head of the femur is continuous with the neck of the femur which joins it to the shaft.
Two bony prominences—the greater and less- er trochanters—mark the junction of the neck with the shaft. The neck meets the shaft posteriorly at a prominent, rounded ridge (the notch on the anterior margin of the ilium sepa-
rates the anterior superior iliac spine from the ant- erior inferior iliac spine which lies immedi- ately above the acetabulum. The anterior inferior iliac spine has two parts—the upper for attach- ment of the tendon of the rectus femoris muscle, and the lower for attachment of the iliofemoral ligament of the hip joint. Trace the outer lip of the iliac crest posteriorly, until you feel a low promi- nence—the tubercle of the iliac crest. This is the widest part of the pelvis. Further posteriorly, the iliac crest turns downwards to end in the pos- terior superior iliac spine at the level of the second sacral vertebra.
The outer gluteal surface of the ilium is marked by three ridges, or gluteal lines, which curve up- wards and forwards across it. These gluteal lines (posterior, anterior, and inferior) are formed by the attachment of the deep fascia between the gluteal muscles. The portion between the lines marks the areas of attachment of these muscles to the ilium [Fig. 13.1].
The greater trochanter of the femur can be palpated indistinctly, immediately in front of the surface depression on the side of the hip [Fig. 13.3].
The top of the trochanter lies at the level of the pubic crest. The head of the femur can be felt in- distinctly, even though it is deeply buried in mus- cles. To do this on yourself, place your finger just below the inguinal groove at the mid-inguinal point, i.e. midway between the anterior superior iliac spine and the pubic symphysis. Press firmly, and rotate your limb medially and laterally. The head will be felt moving behind the muscles. With lighter pressure, the femoral artery can be felt pulsating at the same spot.
Study the main features of the femur, with refer- ence to Figs. 13.3 and 13.4.
The spherical head of the femur fits into the acetabulum where it articulates with the C-shaped lunate surface. The lunate surface is a broad strip of articular bone at the periphery of the acetabulum which partially surrounds the central non-articular acetabular fossa. This fossa is continuous interiorly with the floor of the acetabular notch between the ends of the lunate surface. The acetabular notch is converted into a foramen by the transverse ligament of the acetabulum which bridges the notch and completes the acetabular margin. The transverse ligament of the acetabulum and the margin of
Neck Head Greater trochanter
Intertrochanteric line
Lateral epicondyle
Lateral condyle
Patellar surface Medial condyle Medial epicondyle Adductor tubercle Vascular foramina
Lesser trochanter
Fig. 13.3 Right femur (anterior aspect).
mebooksfree.com
162
The front and medial side of the thigh
the fibrous capsule of the hip joint and transmit blood vessels to the neck. Note the foramina on the neck of the femur for these vessels. These ves- sels form the main blood supply for the head and neck of the femur. The greater trochanter projects above, and medially over, the neck posteriorly, and the bony depression on its medial side is the trochanteric fossa.
The shaft of the femur is covered by muscles and cannot be felt easily. It is convex anteriorly, particularly in its proximal half. Most of its surface is smooth, except for a linear elevation (the linea aspera) posteriorly in its middle two-quarters.
Superiorly and inferiorly, the medial and lateral lips of the linea aspera separate. Superiorly, these diverging lines pass on either side of the lesser tro- chanter and the pectineal line which descends from it. The continuation of the medial lip forms the spiral line anteriorly, and the continuation of the lateral lip forms the rough gluteal tuberosity posteriorly. The spiral line becomes continuous above, with the intertrochanteric line on the ante- rior surface of the femur. A faint bony ridge along the lower margin of the greater trochanter joins the intertrochanteric line anteriorly, with the gluteal tuberosity posteriorly. Inferiorly, the lips of the linea aspera diverge to form the medial and lateral supracondylar lines [Fig. 13.4]. These lines form the boundaries of the flattened popliteal surface of the femur. The lateral supracondylar line con- tinues down to the lateral epicondyle. The medial line continues to the adductor tubercle on the medial epicondyle of the femur but is interrupted where the femoral artery crosses it to become the popliteal artery.
The distal end of the shaft of the femur widens into the medial and lateral condyles. Posteri- orly, the condyles are separated by a wide inter- condylar fossa. Anteriorly, the condyles unite in the grooved patellar surface. The lateral sur- face of this groove is wider and projects further forwards than the medial surface. The margin of the lateral surface may be felt, proximal to the patella, when the knee is flexed. The medial and lateral epicondyles are flattened, conical projec- tions from the surface of each condyle [Figs. 13.3, 13.4]. Each epicondyle shows some additional bony features. The lateral epicondyle gives attach- ment to the lateral head of the muscle gastrocne- mius. Below the lateral epicondyle is a fossa with a groove running posteriorly from it. The tendon intertrochanteric crest) which extends from
the greater trochanter above to the lesser tro- chanter below. Anteriorly, the neck meets the shaft in a rough intertrochanteric line which extends between the two trochanters. This line gives attachment to the powerful iliofemoral ligament—a thickening of the fibrous capsule of the hip joint.
The neck forms an angle of approximately 125 degrees with the body of the femur. A thick bar of bone in the lower part of the neck trans- mits compressive forces applied by the weight of the body on the head of the femur. The surface of the neck is ridged longitudinally by bundles of fibres (retinaculae) which are continuous with
Neck
Trochanteric fossa Greater trochanter Quadrate tubercle Intertrochanteric crest
Gluteal tuberosity
Lateral supracondylar line
Vascular foramina
Lateral epicondyle Lateral condyle
For anterior cruciate lig.
For posterior cruciate lig.
Medial condyle Medial epicondyle Adductor tubercle
Popliteal surface Groove for femoral vessels Medial supracondylar line Linea aspera Spiral line Pectineal line Lesser trochanter Vascular foramen Pit for ligament
Head
Intercondylar notch Fig. 13.4 Right femur (posterior aspect).