Joints ... & Lady Gaga

By now you've probably heard - Lady Gaga has cancelled the remainder of her Born This Way Ball Tour due to a hip injury.  Specifically, the issue is reported to be a labral tear at her hip joint, and some sources are speculating this may have been exacerbated by lupus (although it has not been confirmed that she actually has lupus, despite an apparent family history).

We just finished covering joints in my anatomy class, so let's talk about what might have gone down in Our Good Lady's hip, shall we?

Hip Joint Anatomy

The hip joint, also known as the acetabulofemoral joint, is the connection between the bone of the thigh and the pelvis (at the hip bone/os coxa).  Specifically, the head of the femur ("thigh bone") forms a ball and socket joint with the acetabulum (the cup-shaped indentation) of the hip bone, hence the name acetabulofemoral joint.  The hip joint is a synovial joint, which means it has a complex structure that includes supporting tissues, a joint cavity and synovial fluid, and it is also a diarthrosis, which means it is a freely moveable joint.

As a synovial joint, the hip joint is stabilized by a series of structures including ligaments and surrounding muscles.  There is also the labrum, a ring of fibrocartilage that helps the acetabulum (the depression in the hip bone) to grip the femoral head and make dislocation less likely.

Left hip joint, disarticulated

The consensus seems to be that folks who are especially active with their hip joints are at a higher risk of injuring a labrum - ballet dancers keep coming up as a prime example.  While she's not exactly a prima ballerina, I suspect folks who have seen Lady Gaga do her thing would agree she's quite active with her hip joints.  As such, I feel comfortable putting her in a category of folks who are more likely than most to tear a labrum.

When the labrum tears, depending on the severity of the tear symptoms can range from pain and stiffness to loss of mobility at the joint.  The treatment will depend on the severity of damage and the symptoms - for some this may be a course of anti-inflammatory medications and physical therapy, for others this includes surgical intervention.  Lady G falls in the latter category, suggesting her tear was on the more serious end of the spectrum.

Youch.

Lupus & Joint Function

Now for the lupus part.  Lupus erythematosus is a family of autoimmune conditions - "autoimmune" refers to the body's own immune system attacking and damaging/destroying a tissue or organ that it otherwise should leave alone.  As with many autoimmune disorders, the exact cause of lupus is not known.  The tissues/organs it attacks can vary, but one that is often cited is the joints - this often manifests as joint pain and swelling in affected individuals.  One not-so-common lupus-related complication cited in some resources is avascular necrosis, a condition of diminished blood supply to bones resulting in bone tissue death and structural failure of the tissue.  One of the most common areas affected by this complication is the hip joint.

In an interview in 2010, the Lady spoke of a family history of lupus and the fact that she had tested "borderline positive" herself.  Now whether this makes her more likely to experience a labral tear ... yeah, I don't know.  Folks with lupus are more likely to experience inflammation in and around their joints and from the arthritis-related research I've done in the past, joint inflammation can contribute to joint damage.  I have no idea if that includes increased likelihood of cartilage tears.  Given LG's profession and the recognized labrum-associated occupational hazards thereof, I suspect she could well have injured her labrum without the help/exacerbation of a pre-existing joint-related condition.  And as someone who is trained only academically in orthopedics, is not a clinician and did not specialize specifically in joints ... my professional opinion, along with $2, may just get you a cup of coffee.


References

Floyd, R.T., Adams, J.B. (2009) "Chapter 9: The Hip Joint and Pelvic Girdle." Kean University Kinesiology. Retrieved 24 February 2013 from 

http://www.kean.edu/~jeadams/docs/Kinesiology/Kines_Power_Points/Kines_Chap_9.pdf.

"Hip labral tear." (2011) Mayo Clinic. Retrieved 24 February 2013 from http://www.mayoclinic.com/health/hip-labral-tear/DS00920.

"Lupus." (2011) Mayo Clinic. Retrieved 24 February 2013 from http://www.mayoclinic.com/health/lupus/DS00115/.

"Systemic lupus erythematosus." (2012) ADAM Medical Encyclopedia/PubMed Health. Retrieved 24 February 2013 from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001471/.