Unusual Osteocartilaginous Prominence or Bump Causing Femoroacetabular Impingement After Septic Arthritis of the Hip A Report of 2 Cases in Preadolescence

Abstract

Background: Few data are available concerning the indications, outcomes, or optimum timing of femoral osteochondroplasty in patients with late sequelae of septic arthritis of the hip. Methods: This paper presents 2 unusual cases of Choi type II sequelae associated with a large osteocartilaginous prominence or bump of the femoral head, responsible for cam-type femoroacetabular impingement in preadolescence. Results: Two active preadolescents presented with groin pain after activity, a slightly antalgic gait, and difficulty squatting fully. On physical examination, both had less than 20 degrees of internal rotation with the hip in 90 degrees of flexion and a positive impingement sign, whereby groin pain was provoked by hip flexion, adduction, and internal rotation. One patient underwent osteochondroplasty and femoral valgus osteotomy, and the other osteochondroplasty alone, through surgical dislocation. Postoperatively, both had markedly improved free hip motion and no impingement sign. Conclusions: Patients with type II sequelae before reaching skeletal maturity may present with femoroacetabular impingement symptoms. These 2 cases show that impingement-free hip motion through surgical dislocation improves symptoms.