To the Editors:

We thank Dr. Reichenbach and colleagues for their interest in our case report. The main purpose of our report was to caution rheumatologists against always attributing hip pain to arthritis. Our patient had an acetabular labral tear with which he presented to our clinic, and this had previously been diagnosed as a monarthritis. We acknowledge that a cam-type femeroacetabular impingement (FAI) could have predisposed the patient to this complication. We commend Reichenbach et al for carefully analyzing the case and suggesting this possibility. In fact, the patient is already under the care of our orthopedic colleagues.

We would like to bring to the attention of the readers the fact that cam-type FAI can be seen in up to 28% of asymptomatic people (1). Hence, hip pain in patients with cam-type FAI can be due to other causes, and an acetabular labral tear or secondary OA could be contributory. It should also be noted that there is some degree of controversy concerning the radiographic diagnosis of FAI, including a lack of consensus among readers and the requirement for advanced imaging modalities (2). Even experienced readers can disagree on the diagnosis of this entity. Our case report and the comments of Reichenbach et al together suggest that this is an area where further research is needed.

  • 1
    Beaule PE, Hack K, Rakhra K, DiPrimio G. Prevalence of CAM type FAI morphology in 200 asymptomatic volunteers (SS-29). Arthroscopy 2009; 25: e16.
  • 2
    Clohisy JC, Carlisle JC, Trousdale R, Kim YJ, Beaule PE, Morgan P, et al. Radiographic evaluation of the hip has limited reliability. Clin Orthop Relat Res 2009; 467: 66675.

N. Haroon MD*, F. D. O'Shea MD*, D. Salonen MD*, R. D. Inman MD*, * Toronto Western Hospital and University of Toronto, Toronto, Ontario, Canada.