Acta chirurgiae orthopaedicae
et traumatologiae Čechoslovaca

Acta Chir Orthop Traumatol Cech. 2012; 79(3):275-278 | DOI: 10.55095/achot2012/041

Osteoid Osteoma of the Femoral Neck Mimicking Monarthritis and Causing Femoroacetabular ImpingementCase report

G. W. HERGET^1,2,*, N. P. SÜDKAMP¹, J. BÖHM³, P. HELWIG²

¹ Department of Orthopaedics and Traumatology and Tumorcenter Ludwig Heilmeyer - Comprehensive Cancer Center Freiburg, University Medical Center, Freiburg i. Br., Germany

² Department of Orthopaedics and Traumatology, University Medical Center, Freiburg i. Br., Germany

³ Institute of Pathology, University Medical Center, Freiburg i. Br., Germany

Different aetiologies including the femoroacetabular impingement (FAI) may cause a painful hip, especially in young patients. Two general types of femoroacetabular impingement have been described, the pincer- and the cam type impingement. The latter is characterized by a femoral deformity, usually a bump on the head-and-neck junction that impinges on the acetabular rim. The authors describe the case of a 21-year-old male, bodybuilder, suffering from progressive hip pain with impairment of exercise tolerance, gait and other daily activities. Besides limitation of hip internal rotation physical examination was normal. He had a transitory response to non-steroid anti-inflammatory drugs. Initially performed MRI of the pelvis shows predominant inflammation of the hip joint. In external performed arthroscopy the biopsies of the capsule demonstrated chronic synovitis. In the follow up hip pain remains, however, diagnosis was still unclear. Re-evaluation of the formerly performed and a follow up MRI, and of an additional CT, the findings were compatible with an osteoid osteoma in the femoral cervico-cephalic transition causing itself a cam impingement and monarthritis. The adopted therapeutic strategy consisted on arthroscopic excision of the nidus and trimming of the femoral neck, with clinical recovery after surgical intervention.

Keywords: femoroacetabular impingement, FAI, osteoid osteoma, monarthritis

Published: June 1, 2012  Show citation