Clinical Pearl #6: Overview of Hip Diagnoses
Now that we have a better understanding of various contributing factors related to “hip issues or insufficiencies” as noted in previous pearls, let’s discuss hip diagnoses in a way that’s understandable. These diagnoses result from a physician consultation, and typically involve an x-ray and/or MRI. Hip orthopedic specialists can give you a preliminary diagnosis without radiologic testing due to the number of hips they see daily, and order tests for confirmation. When discussing results, terms will be introduced like “femoroacetabular impingement”, or FAI, “torn labrum”, “dysplasia”’, “borderline dysplasia”, “partial tear of (a muscle)” to name a few. Below introduces some of these common diagnoses.
Femoroacetabular Impingement, FAI:
Impingement happens when two things come together and create abnormal strain, stress or a pinch-like result. FAI results when the body produces extra bone around the neck of the femur and/or around the acetabulum. This commonly happens during adolescent years, or by the time we reach our 20s. The onset of pain may present as a teen or at a later age. This condition contributes to less joint movement in certain ranges as the extra bone comes into contact on each side of the joint sooner than if it wasn’t present. This creates abnormal mechanics and can contribute to a torn labrum or injury to articular cartilage, or cartilage lining the joint.
Hip Labral Tear:
The labrum is a fibrocartilaginous ring around the acetabulum assisting with the stability and health within the joint. A torn labrum can be a result of a one time, abnormal but forceful blow. More commonly, it is caused by repetitive, abnormal forces over a long period of time. Anatomical issues, such as FAI or hip dysplasia, can be a contributing factor. Just about anyone with hip issues will have a torn labrum. Identifying the relationship between the tear and your anatomy is the important part if surgery may be a consideration.
Hip Dysplasia:
This is insufficient bony coverage at the acetabulum, commonly seen in the anterior joint or lateral joint. Many times patients will hear this term, or that the socket is relatively shallow compared to “normal”. This contributes to micro instability over time which is difficult for the ligaments of the hip to control. Inherently, the hip relies on bony anatomy for optimal stability, and when this is lacking, the ligaments must do more with less. Musculature surrounding the hip also takes on a different role to help stability, contributing to pain and dysfunction. Borderline dysplasia has greater coverage than a dysplastic joint, but the amount of instability may still be a factor contributing to pain and dysfunction.
Muscle tears:
Muscle tears can result from an acute injury, a quick overstretch in a weighted position. They can also be caused by a chronic condition due to excess, abnormal strain on a tendon. This chronicity coincides with long standing faulty mechanics and/or muscle dysfunction around the hip. A torn muscle can be a primary source of pain in which an MRI is ordered, such as upper hamstring pain with an MRI finding of partial tearing of the hamstring tendon. An MRI for the hip may also diagnose small, partial tears of other muscles around the joint. While this may be an “incidental finding”, one which wasn’t anticipated but is present, it may or may not be a contributing factor in pain. And, an incidental finding of a small muscle tear can be treated with conservative management, including physical therapy. Consult your physician regarding any muscle tear to identify if it needs surgical repair.
Articular Cartilage:
This type of cartilage is located within every joint of the body. If you have ever seen the joint at the end of a chicken leg, even if you are vegan, it is the shiny, white, smooth substance along that joint surface. Articular cartilage helps joints with shock absorption and nutrition. Shearing forces related to FAI or micro instability with dysplasia can contribute to articular cartilage damage. While the body cannot reproduce or fix articular cartilage tears, a surgical procedure called a microfracture is commonly used to try to “fix” the damage. Consult your surgeon for more information.
Femoral Torsion:
This is an excess rotatory condition within the actual femur bone affecting the angulation of the neck, therefore how the head of the femur interfaces with the hip socket. This is also known as femoral anteverion or retroversion, depending on the direction of the excess rotation. An example of femoral anteversion is when an adult can “W sit” where the pelvis sits comfortably while the lower legs are to the outside of the pelvis, and difficulty sitting “criss cross applesauce”.
Due to the nature of anatomical differences with FAI and/or dysplasia, there is a variety of the capacity for individuals to engage and use muscles sufficiently. The body may have learned a long time ago how to use these muscles through learned compensatory mechanisms compared to someone who has neither of these issues. These patterns of movement can contribute to greater loads and stains on tendons as specific muscles local to the hip are unable to do their job sufficiently. While physical therapy can help assess these issues, and work with you conservatively to help improve these movement patterns and muscle activation, it will not “fix” underlying issues of a torn labrum or hip dysplasia. Altering the joint mechanics through muscle activation, controlled mobility or improved stability can change force distribution within a joint, thus potentially lessening pain.