HIP BONE STRESS INJURIES & LABRAL TEARS
Here's the setup:
A runner comes in to see you with hip pain. It started gradually a few weeks ago, and has consistently gotten worse as she continues to run. She reports pain and aching in the front of her hip a few hours after runs, and is starting to experience some night pain as well.
You decide to refer her for imaging to rule out a bone stress injury and the results come back with:
Shallow tear superior labral attachment, 2-3 mm depth, 11-1:00 with labral attenuation
Bandlike high signal femoral neck midcervical to basicervical location, 1x2.5cm/transverse and longitudinal/25% femoral neck cross-section
Mild adjacent cortical endosteal thickening and linear signal indicating likely incomplete stress/fatigue fracture
It’s not uncommon to see coinciding intra-articular and bone pathologies on imaging. So what do we attribute this athlete’s pain to and how do we initiate treatment?
We know from the literature that asymptomatic labral tears are quite common among the general population. Studies determining rates of pain-free labral tears among various populations have ranged from 39% in a group of volunteers age 19-41(1), to 81-86% in a population of US Air Force personnel (2).
It has been suggested that labrum pathology seen in routine imaging may “represent an incidental finding rather than the underlying cause of the patient’s pain” (3).
Knowing this, in addition to the finding of a bone stress injury on imaging, we want to ensure we treat this as a bone stress injury, first and foremost. Not only is this more likely to be the cause of the runner’s pain, but it’s also more likely to progress to a more significant injury if not managed appropriately, particularly in the case of a high-risk site like the femoral neck.
When the athlete reads the report, it’s likely she’ll have concerns about both issues - what does the labral tear mean? Will she need surgery? Will she have to stop running?
Educating the runner that the healing of the bone stress injury is priority #1, since the labral pathology could be an incidental finding versus the cause of the runner’s pain is important in alleviating fears associated with the labral tear diagnosis. There are cases where bone marrow edema appears on imaging and the athlete is asymptomatic, but I would venture to say this occurs less commonly than asymptomatic labral tears. As a result, your initial intervention will emphasize bone healing.
So what differs between initial intervention for a BSI + labral tear versus labral tear alone?
In the case of a BSI, we’ll want to be more conservative with weight-bearing, strength programming and pain guidelines throughout rehab. Most of the time, particularly with BSIs in high-risk sites, we want to offload the affected site as much as necessary but as little as possible to allow pain-free activities of daily life. This may require the use of crutches in the case of a hip or pelvic BSI, depending on the site and grade of injury.
With our exercise programming, we’ll minimize stress to the affected site before gradually reloading. For example, with a femoral neck stress fracture we’ll avoid resisted hip flexion exercises until they are pain-free during and after. We’ll want to continue stressing this injured site as tolerated throughout the runner’s rehab to promote continued bone remodeling.
By contrast, with labral tears alone we can continue to load the limb and allow exercises within a tolerable level of discomfort. We may still modify the volume or intensity of running, but it’s generally safe to continue running and walking at some level. Our programming should include exercises that strengthen all the muscles surrounding the hip and continuing these exercises through a low level of discomfort is safe and encouraged.
If you’re looking for help with recovery from either or both of these things, or looking for guidance in helping your own patients with these issues, I'm here for it - click below to schedule a chat!
Lee, A. J. J., Armour, P., Thind, D., Coates, M. H., & Kang, A. C. L. (2015). The prevalence of acetabular labral tears and associated pathology in a young asymptomatic population. The Bone & Joint Journal, 97(5), 623-627.
Schmitz, M. R., Campbell, S. E., Fajardo, R. S., & Kadrmas, W. R. (2012). Identification of acetabular labral pathological changes in asymptomatic volunteers using optimized, noncontrast 1.5-T magnetic resonance imaging. The American journal of sports medicine, 40(6), 1337-1341.
Tresch, F., Dietrich, T. J., Pfirrmann, C. W., & Sutter, R. (2017). Hip MRI: prevalence of articular cartilage defects and labral tears in asymptomatic volunteers. A comparison with a matched population of patients with femoroacetabular impingement. Journal of Magnetic Resonance Imaging, 46(2), 440-451.