title: Femoroacetabular impingement and its implications on range of motion: a case report.
abstract: BACKGROUND
  Femoroacetabular impingement leads to limited hip motion, pain and progressive damage to the labrum. Assessment of the amount and location of excessive ossification can be difficult, and removal does not always lead to pain relief and an increase of function. One of the challenges ahead is to discover why certain cases have poor outcomes.
  
  
  METHODS
  The technical and clinical results of two consecutive arthroscopic shavings of an osseous cam protrusion are described in our patient, a 50-year-old Caucasian man with complaints of femoroacetabular impingement. At 12 weeks after the first arthroscopic shaving, our patient still experienced pain. Using a range of motion simulation system based on computed tomography images the kinematics of his hip joint were analyzed. Bone that limited range of motion was removed in a second arthroscopic procedure. At six months post-operatively our patient is almost pain free and has regained a range of motion to a functional level.
  
  
  CONCLUSIONS
  This case demonstrates the relevance of range of motion simulation when the outcome of primary arthroscopic management is unsatisfactory. Such simulations may aid clinicians in determining the gain of a second operation. This claim is supported by the correlation of the simulations with clinical outcome, as shown in this case report.
authors.affiliation: Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands. p.r.krekel@lumc.nl.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Krekel
authors.forename: Anne Jh
authors.initials: AJ
authors.lastname: Vochteloo
authors.forename: Rolf M
authors.initials: RM
authors.lastname: Bloem
authors.forename: Rob Ghh
authors.initials: RG
authors.lastname: Nelissen