Hip Joint Flashcards
Parts of the hip joint
Articular cartilage head of the femur ligamentum teres obturator artery transverse acetabular ligament acetabular labrum (fibrocartilagenous)
Hip joint
strong and stable joint
comprised of th articulation between the acetabulum of the innominate bone and the head of the femur
The orientation of the acetabulum and head of the femur
anteverted and the angle is about 15 degrees
-allows for great deal of stability posteriorly
Intertrochanteric region
occurs along the base of the neck of the femur
Blood supply to the head of the femur
Medial circumflex femoris artery actually comes off the profunda femoris in a posterior direction rather than a medial one
Lateral circumflex femoris a. comes around anteriorly not laterally
they both come off profunda and deep femoral a.
also, minor branches from the artery of ligamentum trees
obturator artery
Anastomotic network
the lateral circumflex artery gives off a descending branch along the shaft of the femur and an ascending branch which anastomoses with the medial circumflex. this anastomotic network forms the reticular arteries which are really the main concern in fx of the femoral head and neck
Normal neck-shaft hip angulation
115-135
greater than 135 neck-shaft hip angulation
coxa valga
less than 115 neck-shaft hip angulation
coxa varus
angle of femoral head in kids
higher than 15 = explains why they are pigeo-footed or have a in-toeing gait
the angle will reduce to a value closer to 15 as kids mature
otherwise it is a developmental pathology
angle of acetabulum
anteverted to 15
medial wall of the acetabulum is very thin
does not provide much support but the posterior and anterior columns are very thick
what is the inverted Y of acetabulum
the oblique angle is 45
tilted downward
thinness of the medial wall of the acetabulum
PE of the hip
pain ROM palpation mandatory neurovascular exam leg length discrepancies Trendenlenberg sign Thomas test Faber test
What are the normal HIP ROM
always compare normal vs non normal Extension : 20-30 Flexion: 135 Abduction: 45-50 Adduction: 20-30 Internal rotation: 30-40 External rotation: 30-40
Trendelenberg test
maneuver for assessing hip abductor function
the contralateral iliac crest should rise indicating that the planted side’s gluteus medius is contracting and holding the innominate up
A POSITIVE TEST = contralateral iliac crest dropping down
even if the iliac crests stay medial, the gluteus medius function is abnormal
because the hip is not rising
abductor weakness or hip dysplasia (hip is dying!!)
Galeazzi test
anatomic short leg or functional short leg
useful for kids
assessing the femur by putting the knees in flexion which takes the tibia out of the equation, this person has a shorter femur
Etiology of short leg
hip degeneration
-not actually caused by hip degeneration
degeneration -> pertusio -> short leg
Pertusio
femoral head breaches the ishioilial line (vertical white line seen in XR)
caused by joint degeneration as in the case of osteoarthritis
Thomas test
test hip flexion contracture
Flex the hip and knee and if the opposite thigh elevates off the table then there is a flexion contracture = this is evaluating the extended hip and you must take into account pelvic tilt/lumber lordosis
Maximum flexion is the point at which the elvis begins to rotate - then allow the hip to extend - if the patient has a hip flexion contracture, the pelvis will start to rock before the leg reaches the examination table when extending the leg
Faber test
detects sacroiliac pathology
nonspecific
stress manuever
positive test = increased pain
Flexion
Abduction
Extension
Rotation
What is DTR?
deep tendon reflex
What other physical findings are important for PE of hip?
dermatomes
motor testing
pulses
Etiology of hip pain
extra-articular intra-articular regional extra regional soft tissue defects osseous defects
Ddx of the hip
Trauma - hip fx (IT/neck) ; hip dislocation
Extra-articular - trochanteric bursitis, iliotibial band tendonitis, sacroilitis (+FABER), tumor, inguinal hernia, lumber disc herniation
Intra-articular - labral tears, loose bodies-fragments, synovitis (PVNS), septic arthritis (esp. with replacements), synovial chondromatosis, osteoarthritis, osteoarthritis, osteonecrosis
extra-regional ddx of the hip
lumber spine, viscera, and abdominal contents can refer pain to hip and groin
Referred pain from the hip
knee and buttocks
pain to the medial thigh and knee may be from the obturator nerve whereas pain from the hip felt in the buttock may be from sciatic nerve
osteoarthritis
affects larger joints
degenerative
noninflammatory
manifestations of the disease - inflammatory but the disease itself is not secondary to inflammation
presentation of osteoarthritis
groin buttock thigh knee pain obturator irritation = referred to medial thigh and knee
Etiology of osteoarthritis
primary - idiopathic, wear/tear
secondary - insult to the hip - trauma, AVN, development, or congenital
Result of osteoarthritis
subchondral sclerosis
subchondral cysts
-due to loss of articular cartilage which increases the coefficient of friction between two bones
XR will show subchondral sclerosis
very radiopaque area at the articulation
- indicates that the cartilage has rubbed away from the bone and the bone has become hard
- occurs at the superior dome of the acetabulum
XR of osteoarthritis
joint space narrowing
hardening and thickening of the bones
hyaline cartilage is gone
Tx of OA
disease usually gets worse - does not get better - will only get worse
hip replacement is indicated if first line tx does not work
Pertrusio in OA
femoral head “herniates” through the acetabulum as will be evidenced by a breach of the ischioilial line on XR
Conservative Tx of OA
preserve activity and motion and control of pain
-avoid high impact activities, WEIGHT CONTROL
-Tylenol+NSAIDs
injections and assistive devices
Surgical tx of OA - second line
Total hip replacement
osteotomy
hip resurfacing
arthrodesis
Osteotomy - OA
cut the bone to shorten lengthen or change its alignment and redirect it so that good cartilage is interacting with good cartilage
hip resurfacing - OA
preserves some of the neck of the femur
especially best for younger patient that can have total hip replacement later - can have metal on metal
arthrodesis - OA
furse the bone
artificial induction of joint ossification bn two bones via surgery
athroplasty - OA
joint surface is replaced with something better
Hip replacement
98% success rate
metal on ceramic is GOOD
Complications of total hip arthroplasty THA
periprosthetic fx
periprosthetic infection
periprosthetic dislocation- caused by malpositioning of the polyethylene liner in the acetabulum
osteolysis - will see bubbling of the bone - indicates that the bone is becoming osteopenic - may be autoimmune response
component loosening - usually a gradual process that is accompanied by pain and often leads to surgical revision
component wear
bacteremia in THA
bacteremia immediately after surgery or even years later (dental work) can settle out on the metal, since there is no vasculature like a normal joint = no immune system
safe ground for bacteria to breed
More complications of THA
DVT tx with low molecular weight heparin MAy lead to infection loss of motion LEG LENGTH DISCREPENCY
leg length discrepancy due to THA
most serious
problems with gait
result of 2 cm difference between the prosthesis and native hip
