Anterior femoroacetabular impingement: a diverse disease with evolving treatment options

Abstract

Anterior femoroacetabular impingement (FAI) is a major etiologic factor in the pathogenesis of hip arthritis. In this condition, mechanical abnormalities of the hip joint lead to early hip dysfunction, inflammation, cartilage injury, and eventual joint degradation. FAI is now more commonly diagnosed and there is an increasing need for a thorough understanding of the broad spectrum of clinical presentation for the disease as well as more precise definition of the possible surgical options.

Figure 1

Femoroacetabular disease patterns. The reduced clearance during joint motion leads to repetitive abutment between the proximal femur and the anterior acetabular rim. (A) normal clearance of the hip, (B) reduced femoral head and neck offset (cam impingement), (C) excessive over coverage of the femoral head by the acetabulum (pincer impingement), and (d) combination of reduced head and neck offset and excessive anterior over coverage can be seen (combined impingement). Reproduced and modified with permission from Lavigne M Parvizi, J Beck, M Siebenrock, KA Ganz, R Leunig, M: Anterior Femoroacetabular Impingement Part I. Techniques of Joint Preserving Surgery. Clin Orthop Relat Res 2004, 18:61-66.

Figure 2

Anteversion pAo for the Treatment of Acetabular Retroversion. This 28-year-old female had a history of bilateral periacetabular osteotomies in adolescence. She presented 10 years after the left sided PAO with symptomatic femoroacetabular impingement due to retroversion of the acetabulum. This anteroposterior radiograph (A) demonstrates major retroversion of the left acetabulum (B) when compared to the right. The patient was treated with anteversion PAO and has an excellent result two years after that procedure (C).

Figure 3

Severe, combined pincer and cam FAI. This 16-year-old male patient presented with a severe combined FAI. The anteroposterior radiograph shows excessive femoral head coverage, acetabular retroversion, rim fractures, and a prominence at the anterolateral head-neck junction (A, B). The patient was treated with surgical dislocation of the hip, osteochondroplasty of the femoral head-neck junction, relative neck lengthening, acetabular rim osteochondroplasty and reattachment of the acetabular labrum. At two-year follow-up (C), the patient was asymptomatic with complete relief of pre-operative pain and stiffness.

Figure 4

38-year-old female with predominant pincer impingement of the right hip. This pre-operative anteroposterior radiograph of the pelvis (A) shows excessive femoral head coverage and ossification of the lateral acetabular labrum. The patient was treated with surgical dislocation of the hip with partial resection of the ossified superolateral labrum, acetabular rim trimming, osteochondroplasty of the femoral head-neck junction and anterior labral reattachment (B, C, d). The patient has marked improvement in symptoms and function one year postoperatively.

Figure 5

Hip arthroscopy and limited open osteochondroplasty of the femoral head-neck junction for cam impingement. Frog-leg lateral of the left hip in an 18-year-old male with activity-related hip pain and impingement (A). At arthroscopy, the patient was found to have a complex anterior labral tear and unstable anterolateral articular cartilage delamination flap (B). he was treated with arthroscopic partial labral resection, chondroplasty and microfracture (C). The femoral head-neck junction was recontoured through a limited open osteochondroplasty. The patient has an excellent result at 2-year follow-up.