A new study by researchers at Hospital for Special Surgery (HSS) in New York City reveals that symptomatic lower back pain resolved in 82% of patients after total hip arthroplasty (THA) and identifies which patients are more likely to have their back pain resolved. This study is available online as part of the AAOS 2020 Virtual Education Experience.
This is another example of “everything is connected to everything else” theory. It seems obvious that any asymmetry in the pelvis or hips would affect how we walk and an uneven gait would then stress the low back.
“For patients, it is important to know that hip and spine arthritis often coexist, and the majority of the time, an individual’s back pain is better after hip replacement surgery,”
A complex interplay exists between the hip and the spine. Some back pain may be caused by abnormal mechanics from hip osteoarthritis.
researchers set out to compare patients whose back pain resolved after THA with those whose back pain did not resolve and identify how to predict this using spinopelvic parameters.
The researchers evaluated and collected demographic data on a consecutive group of 500 patients who underwent THA for unilateral hip osteoarthritis at HSS.
Of the 500 patients, 41% had documented lower back pain prior to their hip surgery.
Of that group, 82% had their back pain resolve after hip replacement at a minimum of one year follow-up.
The average Oswestry Disability Index in these patients preoperatively was 32+/-5% (moderate disability) and post-operatively was 9+/-3% (minimal disability, p<0.001).
all patients whose back pain resolved had a sacral slope change from standing to sitting of more than 10 degrees, while the patients whose back pain did not resolve had a change of less than 10 degrees.
Sacral slope change is a parameter that clinicians examine on a lateral X-ray that shows how much the pelvis and spine move in relationship to each other during different activities, such as going from a standing to a sitting position.
With EDS, our sacral slope change would probably be off the charts. I feel like my pelvis and spine aren’t well connected at all and I have to control them independently.
“There is definitely a group of patients whose back pain predictably goes away after hip replacement surgery, and those are people who have flexible spines,” said Dr. Vigdorchik.
We with hEDS certainly have extremely flexible spines – when they’re not rigidly held by muscular effort.
we saw specific changes in patients with flexible spines, those were the patients whose back pain very reliably went away. Their back pain was exacerbated or even caused by their hip arthritis.
Then there were certain patients who had a stiff, degenerative spine whose back pain did not go away, and that is because their spine arthritis had progressed to the point beyond which the hip was causing an effect.