Applied Anatomy

Trendlenberg's gait
When any of the features of lateral balance control fails, the supporting is upset. The pelvis tends to fall on the unsupported side when the individual stands on the affected limb. This is called Trendelenberg sign. The person walks with a characteristic lurching or waddling gait.

In A : Negative trendlenberg's test . The hip abductors are acting normally tilting the pelvis upwards when the opposite leg is raised from the ground

In B : Positive Trendelenberg's test . The hip abductors are unable to control the dropping of the pelvis when the opposite leg is raised

Causes of such a condition include:

  • Paralysis of the gluteus minimus and medius
  • Dislocation of the hip joint
  • Fractures of the neck of the femur
  • Collapse of the head of the femur e.g. from avascular necrosis, slipped epiphysis, tuberculosis of head of femur
  • Severe arthritis of the hip joint

 

 

Sciatic nerve

Can be compressed at lower border of gluteus maximus by sitting on a bench with a sharp edge.

May be injured by misplaced deep intravascular injections. To prevent this, the injection is usually given in the superolateral quadrant.

May be injured in posterior dislocation of the hip joint.

 

 

Sciatic Hernia
Pelvic structures may protrude through the greater sciatic foramen. This is called sciatic hernia. It compresses the

contents of the foramina and may present with pain, numbness and weakness in the lower limb if sciatic nerve is

compressed.
 

Trochanteric bursitis

The extensive bursa between the great trochanter and the gluteal aponeurosis may be a site of infection. Patient

complains of pain and swelling in the trachanteric region. Sometimes there may be a pus discharge.

 

Snapping hip

In this condition, a snap is heard and felt on certain hip movements. The snap is attributed to slipping of a tendinous

aponeurosis- probably that of the gluteus maximus over the greater trochanter. It is harmless and treatment is not

required.

 

Slipped disc
 
Pain of a prolapsed or strained lumbar intervertebral disc if often referred to the gluteal region or lateral aspect of the

thigh.


Weaver's bottom
Inflammation of the bursa over the ischial tuberosity
 

Piriformis syndrome

When the sciatic nerve divides in the pelvis, the common peroneal nerve may exit either:

  • below Piriformis
  • pierce piriformis
  • pass above piriformis

When it pierces piriformis, it may be compressed by contractions of this muscle. This causes piriformis syndrome.

 

 
 
Gluteal region and back of the thigh

Angle of inclination:

The neck is about 5cm long and makes an angle of 125 ° with the shaft in males and in females (about 110° ). This is called the angle of inclination. It is widest at birth and diminishes with age till adolescence.

 

Angle of anteversion

The neck is also tilted slightly forward at an angle of 10-15° . This is the angle of anteversion.

The proximal border of the greater trochanter is level with the centre of the femoral head.

 

Bryant's triangle:

With the patient lying supine:

  • Drop a perpendicular from the anterior superior iliac spine to the horizontal
  • Project a second line upwards from the tip of the greater trochanter to meet the first line at 90°
  • Join the anterior superior iliac spine to the tip of the greater trochanter.

 


Nelaton's line:

This is a line between the anterior superior iliac spine and the ischial tuberosity, with the patient in the supine position. The tip of the greater trochanter lies on or below this line. If it lies above the line, the femur has been displaced upwards.

 

Shoemaker's line:

A line projected on each side of the body from the greater trochanter beyond the anterior superior iliac spine. The two lines normally meet in the midline at or above the umbilicus. If one femur is displaced upwards, the lines meet away from the midline. If both are displaced upwards the lines meet below the umbilicus.