Injuries of Hip Bone
- Fractures of the hip bone are referred to as pelvic fractures
- Avulsion fractures of the hip bone may occur during sports that require sudden acceleration or deceleration forces, such as sprinting or kicking in football, soccer, hurdle jumping and basketball.
- A small part of bone with a piece of a tendon or ligament attached is avulsed e.g. anterior superior and inferior iliac spines, ischial tuberosities, and ischiopubic rami.
Coxa Vara and Coxa Valga
- The angle of inclination between the long axis of the femoral neck and the femoral shaft varies with age, sex, and development of the femur.
- Normally, it is 130 to 160 degrees in children and about 125 degrees in adults.
- When the angle of inclination is decreased, the condition is called coxa vara. It occurs in fractures of the neck of the femur and in slipping of the femoral epiphysis. In this condition, abduction of the hip joint is limited.
- When the angle is increased, it is called coxa valga. it occurs, for example, in cases of congenital dislocation of the hip. In this condition, adduction of the hip joint is limited.
Dislocated Epiphysis of Femoral Head
- In older children and adolescents (10–17 years of age), the epiphysis of the femoral head may slip away from the femoral neck because of a weakened epiphysial plate
- Cause: acute or repetitive traumas that put stress on the epiphysis
- Symptoms: The common initial symptom of the injury is hip discomfort that may be referred to the knee.
- Examination: Xray of the superior end of the femur is usually required to confirm a diagnosis of a dislocated epiphysis of the head of the femur.
- The femur is a commonly fractured bone of the body.
- The neck of the femur is most frequently fractured because it is the narrowest and weakest part of the bone and it lies at a marked angle to the line of weight-bearing.
- It becomes increasingly vulnerable with age, especially in females, secondary to osteoporosis.
Fracture at Upper end of Femur:
1. Subcapital: Fracture at the junction of head and neck of femur
- Occurance: in the elderly particularly common in women after menopause because of a thinning of the cortical and trabecular bone caused by estrogen deficiency
- Produced by: a minor trip or stumble.
- Complication: Avascular necrosis of the head . If the fragments are not impacted, considerable displacement occurs.
- Presentation: The leg is shortened and laterally disclocated..
- The strong muscles of the thigh, including the rectus femoris, the adductor muscles, and the hamstring muscles, pull the distal fragment upward, so that the leg is shortened.
- The gluteus maximus, the piriformis, the obturator internus, the gemelli, and the quadratus femoris rotate the distal fragment laterally, as seen by the toes pointing laterally
2. Transcervical: Fracture in the middle of the neck of femur
3. Intertrochanteric: Between the two trochanters
- Occurance: in the young and middle-aged
- Produced by: direct trauma.
- The fracture line is extracapsular, and both fragments have a profuse blood supply.
- Complication: If the bone fragments are not impacted, the pull of the strong muscles will produce shortening and lateral rotation of the leg.
Fractures of Shaft of Femur:
Fractures of upper third of the shaft:
- The proximal fragment is flexed by the iliopsoas; abducted by the gluteus medius and minimus; and laterally rotated by the gluteus maximus and other muscles.
- The lower fragment is adducted by the adductor muscles, pulled upward by the hamstrings and quadriceps, and laterally rotated by the adductors and the weight of the foot.
Fractures of the middle third of the shaft:
- The distal fragment is pulled upward by the hamstrings and the quadriceps, resulting in considerable shortening. It is pulled backwards by the pull of the two heads of the gastrocnemius.
Fractures of the distal third of the shaft:
- Same as in the middle, however, the distal fragment is smaller and is pulled more towards the back by the gastrocnemius muscle and may exert pressure on the popliteal artery and interfere with the blood flow through the leg and foot.
Gateways to the lower limb
- There are four major routes b y which structures pass from the abdomen and pelvis into and out of the lower limb.
- These are the obturator canal. the greater sciatic foramen, the lesser sciatic foramen, and the gap between the inguinal ligament and the anterosuperior margin of the pelvis.
1. Obturator canal:
The obturator canal is an almost vertically oriented passageway at the anterosuperior edge of the obturator foramen.
It is bordered:
- above by a groove (obturator groove) on the inferior surface of the superior ramus of the pubic bone,
- below by the upper margin of the obturator membrane, which fills most of the obturator foramen, and by muscles (obturator internus and externus) attached to the inner and outer surfaces of the obturator membrane and surrounding bone.
The obturator canal connects the abdominopelvic region with the medial compartment of the thigh.
Contents: The obturator nerve and vessels pass through the canal.
2. Greater sciatic foramen:
The greater sciatic foramen is formed on the posterolateral pelvic wall and is the major route for structures to pass between the pelvis and the gluteal region of the lower limb.
The margins of the foramen are formed by:
• the greater sciatic notch,
• parts of the upper borders of the sacrospinous and sacrotuberous ligaments , and
• the lateral border of the sacrum.
The piriformis muscle passes out of the pelvis into the gluteal region through the greater sciatic foramen and separates the foramen into two parts, a part above the muscle and a part below:
- The superior gluteal nerve and vessels pass through the greater sciatic foramen above the piriformis.
- The sciatic nerve, inferior gluteal nerve and vessels, pudendal nerve and internal pudendal vessels, posterior cutaneous nerve of the thigh, nerve to the obturator internus and gemellus superior, and nerve to the quadratus femoris and gemellus inferior pass through the greater sciatic foramen below the muscle.
3. Lesser sciatic foramen:
The lesser sciatic foramen is inferior to the greater sciatic foramen on the posterolateral pelvic wall. It is also inferior to the lateral attachment of the pelvic floor muscles and connects the gluteal region with the perineum
- The tendon of the obturator internus passes from the lateral pelvic wall through the lesser sciatic foramen into the gluteal region to insert on the femur.
- The pudendal nerve and internal pudendal vessels, which first exit the pelvis by passing through the greater sciatic foramen below the piriformis muscle, enter the perineum below the pelvic floor by passing around the ischial spine and sacrospinous ligament and medially through the lesser sciatic foramen.
4. Gap between the inguinal ligament and pelvic bone:
- The large crescent-shaped gap between the inguinal ligament above and the anterosuperior margin of the pelvic bone below is the maj or route of communication between the abdomen and the anteromedial aspect of the thigh (Fig.
The psoas major, iliacus, and pectineus muscles pass through this gap to insert onto the femur. The major blood vessels (femoral artery and vein) and lymphatics of the lower limb. Nerves lower limb also pass through it, as does the femoral nerve, to enter the femoral triangle of the thigh.