What does the femoral head size tell us?

What does the femoral head size tell us?

Larger diameter femoral heads are associated with increased joint stability through increases in arc range of motion and excursion distance prior to dislocation.

Is there a benefit to head size greater than 36 mm in total hip arthroplasty?

We found that there is no benefit in hip range of movement or hip function when head sizes > 36 mm are used. The risk of revision due to dislocation is lower for 36 mm or larger bearings compared with 28 mm or smaller and probably even with 32 mm.

Are there different sizes of hip replacements?

Total hip arthroplasty (THA) currently comprises a variety of head sizes and bearing types. The size of femoral head used in THA gradually increased from 22 mm in the 1960s to 28 mm in the 1990s, and thereafter to 32 mm in the mid-2000s.

What is a large femoral head?

Large femoral heads, as defined as those bearings of 36 mm and larger, are being used with increasing frequency in modern total hip replacement (THR).

What is femoral head diameter?

The natural size of the femoral head usually ranges from 40 to 54 mm, with smaller sizes usually found in females.

What type of bone is the femoral head?

The hip joint (see the image below) is a ball-and-socket synovial joint: the ball is the femoral head, and the socket is the acetabulum. The hip joint is the articulation of the pelvis with the femur, which connects the axial skeleton with the lower extremity.

What is femoral offset?

Femoral offset is the distance from the center of rotation of the femoral head to a line bisecting the long axis of the femur (Fig. 1). This radiographic measurement should be accurately performed and varies according to the hip rotation.

What is stress shielding effect?

Stress shielding refers to the reduction in bone density (osteopenia) as a result of removal of typical stress from the bone by an implant (for instance, the femoral component of a hip prosthesis).

How big is the ball on a hip replacement?

The size of the ball of the natural hip joint (femoral head) varies and usually ranges from 40 to 54 mm (with smaller sizes in females). During the initial development of hip replacement, the surgeons tried to make the implants which mimic the size of the natural femoral head.

How big is the scar after hip replacement surgery?

Scar. You will have a single scar in the region of your hip and this will measure anywhere between 8 and 20 cms (3 and 8 inches). The length of scar is dependent in part on obesity and musculature.

What is the purpose of the circular femoral head in a hip implant?

The femoral head is articulated into the pelvis and gives the joint different degrees of freedom, which helps the joint movement [6]. With the trauma or injuries and due to the age, these joints must be replaced by artificial implants.

How big is a femoral head?

The natural size of the femoral head usually ranges from 40 to 54 mm, with smaller sizes usually found in females. In the initial development of hip arthroplasty, artificial femoral heads were designed to replicate these anatomical dimensions.

What is the optimal femoral head size for hip replacement surgery?

Femoral head sizes greater than 32 mm offer multiple advantages in physical function and activity levels of patients by improving hip stability, decreasing dislocation rate and increasing range of motion.

What is the normal size of the ball of the hip?

The size of the ball of the natural hip joint (femoral head) varies and usually ranges from 40 to 54 mm (with smaller sizes in females).

How much more stable is the hip with a larger head?

Within each group of head size, the hip was significantly more stable when the cup anteversion increased from 0 degrees to 10 degrees . The difference became insignificant when it increased from 15 degrees to 20 degrees. 4. Hip stability in primary total hip arthroplasty using an anatomically sized femoral head.

Does “large diameter head” total hip arthroplasty improve range of movement?

This study showed that the range of movement was better with the “large diameter head” total hip arthroplasty when compared with 28 mm head total hip arthroplasty or hip resurfacing but still was less than the range of movement of the normal contralateral hip. In addition, functional score (WOMAC score) also correlated with range of movement.