quiz on Hip and knee replacements Flashcards
The acetabulum and the femoral head are covered in __________________, which reduces friction and absorbs shock, allow- ing the bony surfaces to move against each other without causing damage
articular cartilage
acetabular labrum
A ring of fibrocartilaginous material that surrounds the acetabulum. The acetabular labrum adds to the depth of the acetabulum, thereby increasing the surface and strength of the hip joint.
What are the ROM of the hip?
Hip motions include flexion, extension, abduction, adduction, medial (internal) rotation, lateral (external) rotation, and circumduction.
What is the most common and problematic joint disease affecting middle-age and older adults.
OA
Avascular necrosis
a condition that results from poor blood supply to an area of bone, causing bone death. Avascular necrosis is also known as aseptic necrosis or osteonecrosis. It has been associated with alcoholism, cortisone medication use, Cushing’s syndrome, radiation exposure, sickle-cell disease, pancreatitis, Gaucher disease, and systemic lupus erythematosus.
Rheumatoid arthritis:
a chronic systemic inflammatory disorder that causes synovitis of multiple joints. Refer to the “Musculoskeletal and Immunological Disorders”
What are some issues, diseases and conditions of the hip
OA, RA, Avascular necrosis, hip displasia and hip fractures
Hip dysplasia:
a developmental abnormality in which the hip joint is not formed properly. The socket is shallow, and the head of the femur is not well rounded, which increases local stresses on the cartilage.
Hip fractures:
a break in the upper part of the femur. Refer to the “Hip Fractures” section for detailed information on causes, treatment, and prevention of hip fractures.
When might a pt elect to have a hip replacement
when conservative treatments, such as lifestyle and activity modification, medication, occupational and physical therapy, and alternative or complementary treatments, have failed or are no longer effective.
Hip arthroplasty
is joint replacement surgery in which all or part of the hip joint is replaced with an artificial device.
Total hip replacement is also known as total hip arthroplasty (THA) and involves three parts:
- Stem: fits into the femur usually made of titanium-based or cobalt-chromium-based alloys
- Ball: replaces the femoral head made of cobalt-chromium-based alloys or ceramic materials and polished smooth to allow easy rotation in the hip socket and
- Cup: replaces the hip socket can be made of plastic, metal, ceramic, or ultra-high molecular-weight polyethylene, or a combination of polyethylene backed by metal.
A prosthesis in which the ball and stem are combined into a single component is called
a bipolar prosthesis.
Partial hip replacement (hemiarthroplasty) is indicated when
only one half of the joint needs to be replaced. The component replaced is generally the femoral component (i.e., the ball and stem
why would a person get each of these kinds of THA
posterior, posterolateral, anterior (also known as direct anterior), anterolateral, and direct lateral ap- proaches.
The choice is based on surgeon preference, surgeon experience, and the patient’s premorbid condition.
minimally invasive hip replacement is an umbrella term that refers
to variations of conventional THA techniques in which there is less soft tissue and bony dissection.
Minimally invasive surgery (MIS) may require specialized equipment to enhance visualization through the smaller incision and special operating table
What is Hip resurfacing?
an alternative to THA in which the femoral head is reshaped and covered with a metal shell rather than removed.
Hip resurfacing is considered to be a more difficult surgery to perform compared with THA. The disadvantages of hip resurfacing include
Risk of femoral neck fracture, which is not a risk in THA because the femoral neck is removed and ■ ■ High levels of circulating metal ions (i.e., metallosis) from the metal ball moving within the metal socket which may cause pain, swelling, or an allergic reaction in some patients
revision total hip arthroplasty
part or all of the old pros- thesis is removed and replaced with new components.
THA may fail for several reasons, including
mechanical loosen- ing, dislocation, implant failure, periprosthetic fracture, or infection. Patient factors such as obesity, diagnosis of RA or avascular necrosis versus OA, younger age, and higher activity level are associated with higher revision rates
hip resection arthroplasty, also known as a Girdlestone procedure, was commonly performed after failure of a primary THA. In a Girdlestone procedure, the
head of the femur is removed. Al- though pain is alleviated, the limb is shortened, the hip is stiff, and an assistive device is required for walking. In some cases, a Girdlestone can be converted to a THA.
Girdlestone procedures are now considered a last resort or salvage procedure when (4 reasons)
(1) infection has occurred after THA, (2) a failed hip replacement cannot be revised, or (3) THA is not a viable option for a painful hip that is affecting quality of life.
- A Girdlestone procedure may also be performed in cases of primary infective (septic) arthritis.
Which THA approach has a greater risk of dislocation anterior or posterior?
Posterior
Posterior hip precautions
No hip flexion beyond 90° ■■ No hip adduction past neutral ■ No hip internal rotation
Anterior hip precautions
No hip extension ■ No hip external rotation
Global anterior and posterior hip precautions
No hip flexion beyond 90° ■■ No hip adduction past neutral ■■ No hip internal or external rotation ■■ No hip prone laying ■ No bridging
Trochanteric hip precautions
No active hip abductio
weight bearing as tolerated (WBAT)
Patient is allowed to put as much weight as tolerated through the operative extremity, with pain being the limiting factor
Partial weight bearing (PWB)
Patient is allowed to put up to 50% of his or her body weight on the operative extremity
Touchdown weight-bearing (TDWB
Patient is not allowed to bear weight on the operative extremity but is allowed to touch his or her toes to the floor to maintain balanc
Non-weight-bearing (NWB
Patient is not allowed to bear any weight on the operative extremity.
ORIF
Treatment of a hip fracture usually consists of reducing the fracture and holding it in place with an internal device while the bone heals. This type of surgery is known as open reduction internal fixation (ORIF).
Each hip bone is a large, irregularly shaped bone that develops from the fusion during puberty of 3 bones: What are they?
the ilium—the superior, broad, flaring (fan-shaped) portion of the hip bone (2) the ischium—the body of the ischium helps form the acetabular portion of the hip joint and (3) the pubis—the lower, posterior part of the hip bone.
Sacrum:
A spade-shaped bone formed by the fusion of 5 originally separate sacral vertebrae.
Coccyx:
Formed by the fusion of 4 originally separate coccygeal vertebrae. The coccyx is also called the tail bone
The main functions of the pelvis are to support the
spinal column, protect the abdominal organs, transfer weight of the upper body to the lower limbs, and withstand compression and other forces from supporting body weight.
What type of joint is knee?
a double condyloid joint,
What are the movements of the knee
flexion, extension, and medial and lateral rotation.
Between the lateral and medial condyles of the femur and the lateral and medial condyles of the tibia are two articulations:
(1) the inferior joint
(2) the superior tibiofemoral joint.
Ligaments are connective tissue that hold
bones together.
The stability of the knee joint is provided by
its two collateral ligaments and two cruciate ligaments.
The anterior cruciate ligament crosses from the lateral femoral condyle to its insertion site on the medial tibial spine. What does it do?
This ligament restrains anterior subluxation of the tibia relative to the femur.
The posterior cruciate ligament crosses from the medial fem- oral condyle to the posterior aspect of the tibia. What does it do?
It prevents posterior subluxation of the tibia on the femur.
The medial collateral ligament runs from the
medial aspect of the tibia to the medial aspect of the femur.
What does the medial collateral ligament do
stabilizes the knee against valgus (toward the body’s midline) and rotational stresses
The lateral collateral ligament runs from
the lateral femoral condyle and attaches at the head of the fibula.
It is the main stabilizer against varus stress (away from the body’s midline) and also resists external rotation.
Lateral collateral ligament
The menisci are
two semilunar cartilaginous discs, which act as the shock absorbers for the joint.
OA in the knee joint is a result of
the menisci of the knees deteriorating as a result of age-related changes, repetitive trauma, or obesity
A common procedure that can precede a total knee replacement is
knee arthroscopy, a minimally invasive procedure in which a small scope is inserted into the knee. The scope projects a picture of the knee’s interior to a television. If the damage to the knee is not ex- tensive, the surgeon can use various instruments through this small incision to debride or repair damaged tissues
What is a knee arthroplasty?
An arthroplasty is a surgery in which one or more of the articular surfaces of a joint are replaced by a synthetic prosthesis (Figure 22.9). The prosthetic is typically made of a combination of metal and plastic.
A prosthetic knee is made up of three components:
- Tibial component to replace the top of the tibia
- Femoral component to replace the two femoral condyles and the patellar groove
- Patellar component to replace the bottom surface of the kneecap
What are the restrictions after knee replacement surgery?
After the surgery is completed, patients will be allowed to bear weight through their operated leg as tolerated and will not have any restrictions
Continuous passive motion machines
move the operative leg through a controlled, predetermined ROM while the patient is at rest.
knee revision surgery,
part or all of the old prosthesis is removed and replaced with new components.
joint arthroplasty
replacement of joint
what is the most common joint replacement?
total knee replacement
how long does a joint replacement last
used to be 10 years but now the materials are better and it seems to be holding longer.
