Hip Shape May Predict Total Hip Replacement

Hip shape predicted the likelihood of whether patients needed total hip replacements in a recent study presented at the World Congress on Osteoarthritis.

Laura Laslet, Ph.D., is a musculoskeletal epidemiologist at the University of Tasmania in Hobart, Australia, who focuses on osteoarthritic pain. Dr. Laslet and a group of colleagues sought to identify risk factors that anticipated total hip replacement. Although hip pain and hip osteoarthritis are two main predictors for hip replacement, they are not the only indicators. Hip anatomy plays a significant role as well.

Hip Anatomy and Hip Dysplasia

The hip is the largest ball and socket joint in the body. Hip bone parameters, such as decreasing acetabular coverage, were among factors that predicted total hip replacement. The acetabulum, located in the pelvis, is the socket structure of the hip joint. The top part of the thigh bone called the femoral head is the ball. In a healthy hip, the femoral head fits securely into the acetabulum and rotates freely in the cartilage lining.

If the acetabulum does not fully cover the femoral head, the hip joint can become dislocated or partially dislocated. This is known as hip dysplasia. Dr. Laslet found that patients who had decreasing acetabular coverage had a higher risk of total hip replacement.

Risk Factors for Total Hip Replacement

Between 2002 and 2016, Dr. Laslet and her team analyzed 1,100 participants from 50 to 80 years of age from the Tasmanian Older Adult Cohort (TASOAC) Study. The team examined pelvic X-rays, bone density scans, MRIs and hip shape parameters. They looked at data from 40 patients who underwent hip replacements and 762 patients who did not. Patients were compared to others of the same gender, age and BMI.

The study identified other risk factors for total hip replacement, such as:

• WOMAC hip pain (self-administered questionnaire on perceived hip pain, stiffness and physical functions)
• Bone marrow lesions (areas of bone impaction and bleeding caused by trauma)
• Impingements (abnormal friction during hip movement that damages the joint)
• Irregular shaped femoral head
• Osteoarthritis

No other study has considered all these predictors in the same set of data, says Dr. Laslet.

“Combination of measures may allow us to improve models predicting risk of total hip replacement,” Laslet concluded. “All of these things can only help us in finding ways to prevent and treat osteoarthritis. We have shown in our data that age, sex and BMI did not predict total hip replacement independent of pain and hip osteoarthritis” (Healio).

Hip Treatment Reduces Risk of Other Injuries

If you are experiencing hip pain or reduced mobility, call an orthopaedist for a consultation. Limited hip flexibility can place more stress on other structures and can make them more susceptible to injury.