Prevalence of anterior labral tears of the hip in ultra-distancerunners

Investigators:

Marko Bodor, MD (Principal investigator)

Alison Ganong, MD

John Diana, MD

Jonathon Brayton, RN

Abstract

Tears of the hip labrum are a relatively common cause of acute and chronic hip pain in athletes. These tears can also be asymptomatic. Labrum tears have been reported to be present in up to 44% of asymptomatic persons, and in up to 73% of asymptomatic persons greater than 50 years of age. The prevalence of hip labrum tears among ultra-distance runners is unknown. In fact, to our knowledge, there has been no literature written about this subject in this specific population of runners. We would like to determine the prevalence of hip labrum tears among ultra-distance runners using high frequency, diagnostic ultrasonography. High frequency musculoskeletal diagnostic ultrasonography is painless, has no known side effects, and the anterior hip (the site of approximately 90% of hip labral tears) can be scanned in approximately 5 minutes. A screening ultrasound will be performed on both hips of participants to determine the presence or absence of an anterior labral tear in either hip. Runners will be blinded to the results. Follow up surveys will be sent to the participants immediately following the race, 6 months, 1 year, and 3 years to evaluate the presence or absence of symptoms longitudinally over time.

Introduction

Hip pain is common among long distance runners and can be a source of both reduced performance and serious injury. Pathologic acetabular labral tears are increasingly recognized abnormalities that can be a source of hip pain, particularly in the athletic population. Many labral tears, however, are incidental and do not cause pain and therefore would not be considered pathologic. Both types of tears can be significant to clinicians in order to both initiate earlier treatment of pathologic or symptomatic tears and conversely, to avoid unwarranted treatment in patients with asymptomatic tears. Our study will identify ultra-runners with labral tears before a 100 mile endurance run to determine the prevalence of these findings in this unique population of runners. We will then follow these participants over time to determine if any of the asymptomatic tears become symptomatic andvice versa. The findings will allow clinicians to better understand the significance of such findings in this athletic group.

Methods

IRB approval for the study will be obtained from the Adventist Health IRB. Inclusion criteria will include any willing race participant regardless of age, gender, or running experience. All entrants to the Western States Endurance Run 100 mile footrace have qualified to compete in the race. They are all presumed to be experienced runners as they all have had to complete one of the few 100 kilometer or 100 mile qualifying events in a satisfactory time to qualify to run the Western States 100 mile race. All race participants will be offered the opportunity to participate in the study. Exclusion criteria will include race participants who have had prior surgery on either hip. As 100 mile races have relatively few participants (the Western States 100 will have approximately 380 qualified participant runners) obtaining a reasonable sample size can be a challenge so no further exclusion criteria will be proposed.

A total of up to 50 runners will be enrolled as participants in the study allowing evaluation of 100 hips. An ultrasound examination of both hips will be performed on these individuals the day prior to the race. During this initial evaluation, we will ask the participants whether they have had any hip or groin pain in either hip. Follow up surveys will be sent to these individuals within a week of completion of the race, at 6 months, 1 year, and 3 years to determine if they have developed any symptoms in their hips and if so, if they have obtained any treatment for their hip pain. We will also ask if they continue to run and participate in ultrarunning events. Many asymptomatic labral tears are present in the non ultra-running population and do not require treatment. It is not clear whether the presence of a labral tear will become symptomatic in the future in this population. Therefore, we will blind runners to the results of the study until after the three year follow up to avoid unwarranted concern or treatment of these findings.

Results

The results will allow identification of the percentage of asymptomatic (and possibly symptomatic) labral tears in this population. This can be compared to the incidence of asymptomatic hip labrum tears in the general population and to the incidence of hip labrum tears in participants of other areas of athletics. Likewise, this data will give previously unknown insight as to whether these labral tears ever become symptomatic in this population over time and require treatment. Clinicians may benefit from this knowledge to avoid unwarranted treatment of asymptomatic labrum tears and will add to the knowledge regarding the hip labrum in this population. Enhanced knowledge of the prevalence of these tears can help clinicians make more informed recommendations for treatment of patients with hip labral tears.

Literature

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2 Tresch F, Dietrich TJ, Pfirrmann CW, Sutter R. Hip MRI: Prevalence of articular cartilage defects and labral tears in asymptomatic volunteers. A comparison with matched population of patients with femoroacetabular impingement. J Magn Reson Imaging 2016 Dec 16.

3 Guanche CA, Sikka RS. Acetabular labral tears with underlying chondromalacia: a possible association with high-level running.Arthroscopy2005 May; 21(5):580-

4 Jayakar R, Merz A, Plotkin B, Wang D, Seeger L, Hame SL. Magentic Resonance arthrography and the prevalence of acetabular labral tears in patients 50 years of age and older.Skeletal Radiol2016 Aug; 45(8): 1061-7.

5 Lee AJ, Armour P, Thind D, Coates MH, Kang AC. The prevalence of acetabular labral tears and associated pathology in a young asymptomatic population. Bone Joint J. 2015 May 97-B(5): 623-7.

Estimated cost: $1500 - $3000

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