Hip Pathomorphology in Collegiate Athletes and Controls
Condition: Femoroacetabular Impingement; Dysplasia
MeSH terms: Femoracetabular Impingement
Study type: Observational

Summary: 
      The primary objective of this study is to investigate factors hypothesized to influence the
      prevalence of hip pathomorphology (femoroacetabular impingement, dysplasia) in young adults.
      To complete this objective, we will quantify the prevalence of radiographic measures
      indicative of hip pathomorphology in collegiate athletes and age-matched controls. This data
      will allow us to test our main hypothesis, that the prevalence of hip pathomorphology is
      higher in collegiate athletes than age-matched controls. To further elucidate the factors
      which may increase the prevalence of hip pathomorphology, we will correlate the radiographic
      measures to sport involvement history, hip function and demographics, as collected by means
      of a questionnaire.

      The secondary objective of this study is to determine if physical exams (range of motion,
      impingement test) could be used to screen for radiographic measures of hip pathomorphology in
      athletes and age-matched controls. To complete this objective, we will correlate range
      physical exam results to the radiographic measures and determine each exam's sensitivity and
      specificity to detect abnormal morphology.
    

Detailed description: 
      Overview of Hip Pathomorphology. Osteoarthritis (OA) of the hip is the loss of articular
      cartilage in the load bearing areas of the joint. OA affects one in six adults, with hip OA
      affecting 9 million US citizens. Abnormal bony morphology of the femur and/or acetabulum
      (herein called pathomorphology) is believed to initiate damage to the articular cartilage and
      acetabular labrum and may predispose the hip to early OA. This study focuses on two types of
      hip pathomorphology: femoroacetabular impingement (FAI) and acetabular dysplasia. FAI is
      characterized by reduced clearance between the femoral head and acetabulum due to femoral
      head/neck asphericity (cam FAI), acetabular overcoverage (pincer FAI), or a combination of
      the two (mixed FAI). Dysplasia is characterized by a shallow or maloriented acetabulum.

      Elevated Risk of Hip Pathomorphology in Athletes. Hip pathomorphology is a common cause of
      hip pain in athletes, and can limit or end sports participation. Collegiate and professional
      athletes are considered at high risk for symptomatic FAI and dysplasia due to demands placed
      on their hips during repetitive sport-specific motions. Sports which require
      supra-physiologic hip motion may cause underlying bony abnormalities to become symptomatic by
      initiating and/or aggravating chondrolabral damage. For example, hockey requires repetitive
      hip flexion with internal rotation that is hypothesized to lead to increased incidence and
      pain related to FAI.

      Athletes are also considered at high risk for the development of symptomatic FAI because they
      are hypothesized to have a higher prevalence of underlying bony abnormalities. Radiographic
      findings consistent with hip pathomorphology are present not only in symptomatic patients but
      also in asymptomatic individuals. In general population, previous estimates of prevalence are
      15-30% for FAI and 6-7% for dysplasia. It is hypothesized that the prevalence of FAI in some
      athletes may be much higher, but the prevalence of dysplasia is equivalent. High physical
      demand during the critical stages of hip development or beyond may initiate remodeling,
      leading to abnormalities consistent with FAI. This remodeling is not hypothesized to occur
      with dysplasia, but has not been investigated.

      Diagnosis and Treatment of Hip Pathomorphology. Arthroscopic and open surgical treatment of
      symptomatic FAI and dysplasia seeks to reduce pain, improve function and prevent/delay
      osteoarthritis by restoring normal joint morphology. If surgery is performed before
      radiographic evidence of osteoarthritis exists, most professional athletes can return to
      their pre-surgery level of play. For example, 28 hockey players who underwent arthroscopic
      treatment of FAI return to sports at a mean of 3.8 months. Interestingly, those who had
      already developed arthritis or experienced a delay in treatment from the onset of hip pain
      had a delayed return to sport. Thus, early diagnosis and prompt treatment may be important to
      optimize clinical outcomes and facilitate the return to sport for athletic patients.

      While the timeliness of a proper diagnosis continues to improve, misdiagnosis can occur by
      clinicians not familiar with hip pathomorphology. For example, prior to being diagnosed with
      FAI, many patients consult multiple health-care providers and even undergo unnecessary
      surgical procedures. Even professional athletes are not treated immediately, with the average
      time from onset of symptoms to treatment reported to be 29.6 months.

      Motivation. While no study has supported prophylactic treatment of abnormal bony morphology
      in asymptomatic hips, symptomatic hips could benefit from early treatment to prevent further
      chondrolabral damage. The overall goal of this study is to improve the diagnosis and
      timeliness of treatment of hip pathomorphology by 1) identifying "at-risk" populations and 2)
      determining if physical exams could be used to screen members of "at-risk" populations for
      underlying abnormalities.
    

Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Male and Female 18-30 years old and athletes. Age matched controls.
      
Keywords: Collegiate Athletes; Hip Pathomorphology; Age-Matched Controls; Femoroacetabular Impingement; Dysplasia