Prevalence of Cam-Type Femoroacetabular Impingement Morphology in Asymptomatic Volunteers

Abstract

The prevalence of cam-type femoroacetabular impingement deformity is higher in men as well as in individuals with decreased internal rotation. Defining what represents a normal head-neck contour is important for establishing treatment strategies in patients presenting with prearthritic hip pain.

The prevalence of radiographic femoroacetabular impingement in younger individuals undergoing total hip replacement for osteoarthritis

“…This may explain why we observed more pincer cases despite reports that mixed-type impingement is the most common. Our gender distribution for impingement type, however, was consistent with previous literature [5,[12][13][14]. Moreover, many of the subjects had radiographic end-stage OA, which made it difficult to exclude FAI (e.g., it was challenging to distinguish an osteophyte from a pistol grip deformity).…”

“…These findings add to the limited epidemiologic data available on the burden of FAI. The prevalence rates reported to date span a wide range, reflecting differences in the populations sampled, imaging modality used, and the criteria used to define FAI [5,[12][13][14].…”

“…1b). Cam impingement is more commonly found in younger athletic males, while pincer impingement occurs typically in middle-aged females [3,5]. Often, patients present with features of both impingement types [6].…”

Patient-Specific Anatomical and Functional Parameters Provide New Insights into the Pathomechanism of Cam FAI

“…Recent publications have highlighted the prevalence of the cam deformity in the normal population based on the alpha angle [17,18,24]. However, we do not know what factors increase the likelihood that a patient with cam FAI morphology will become symptomatic.…”

“…Many individuals with cam deformities may not experience mechanical impingement or pain symptoms, thus qualifying them as asymptomatic individuals [11,18,26,43]. Therefore, we postulated that FAI symptoms may be related to other anatomical parameters that can exacerbate mechanical impingement in patients at risk of developing symptoms.…”