Journal of Nippon Medical School: Vol.69 No.2 page.192

Journal of Nippon Medical School

Select Language
in Japanese < > in English

Full Text of this Article

in English PDF (193K)

ArticleTitle A Dislocation of the Inner Head in Bipolar Prosthesis with a Self-centering System: A Case Report

AuthorList Kouichi Tanaka¹, Yoshihito Nakayama¹, Ryoichi Murashige¹, Hiromoto Ito², Kiyoshi Yoshihara², Kingo Obama³ and Takeshi Nakase³

Affiliation ¹Department of Orthopaedic Surgery, Daini Hospital, Nippon Medical School, ²Department of Orthopaedic Surgery, Nippon Medical School, ³Department of Orthopaedic Surgery, Kureha General Hospital

Language EN

Volume 69

Issue 2

Year 2002

Page 192-195

Received September 26, 2001

Accepted November 27, 2001

Keywords bipolar prosthesis, self-centering system, impingement, osteoarthritis

Abstract We present a case of inner head dislocation 11 years after the replacement of a bipolar prosthesis with a self-centering system. An 84-year-old woman with osteoarthritis of the left hip underwent a replacement of the Bateman UPF-II bipolar prosthesis in 1987. She fell off a chair on April 19 1998, and felt a sudden sharp pain in the left hip. Roentgenograms revealed that the inner head was dislocated from the outer head. Moreover, on June 19, when she stood up from the floor, the dislocation recurred. On July 23, a revision surgery was carried out. When the outer head was removed from the acetabulum, the bearing insert was markedly worn by the impingement of the femoral stem neck. Because there was no evidence of loosening of the femoral stem, a cemented replacement of the acetabular component was performed. At a 2-year follow-up, she had mild hip pain, but had returned fully to daily living. Our review of current published studies reveals that most inner head dislocations occurred in osteoarthritic patients. Thus, the occurrence of dislocations may be more dependent on patient selection than on failure of the bipolar prosthesis itself.

Correspondence to Kouichi Tanaka, Department of Orthopaedic Surgery, Daini Hospital, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan

ArticleTitle	A Dislocation of the Inner Head in Bipolar Prosthesis with a Self-centering System: A Case Report
AuthorList	Kouichi Tanaka¹, Yoshihito Nakayama¹, Ryoichi Murashige¹, Hiromoto Ito², Kiyoshi Yoshihara², Kingo Obama³ and Takeshi Nakase³
Affiliation	¹Department of Orthopaedic Surgery, Daini Hospital, Nippon Medical School, ²Department of Orthopaedic Surgery, Nippon Medical School, ³Department of Orthopaedic Surgery, Kureha General Hospital
Language	EN
Volume	69
Issue	2
Year	2002
Page	192-195
Received	September 26, 2001
Accepted	November 27, 2001
Keywords	bipolar prosthesis, self-centering system, impingement, osteoarthritis
Abstract	We present a case of inner head dislocation 11 years after the replacement of a bipolar prosthesis with a self-centering system. An 84-year-old woman with osteoarthritis of the left hip underwent a replacement of the Bateman UPF-II bipolar prosthesis in 1987. She fell off a chair on April 19 1998, and felt a sudden sharp pain in the left hip. Roentgenograms revealed that the inner head was dislocated from the outer head. Moreover, on June 19, when she stood up from the floor, the dislocation recurred. On July 23, a revision surgery was carried out. When the outer head was removed from the acetabulum, the bearing insert was markedly worn by the impingement of the femoral stem neck. Because there was no evidence of loosening of the femoral stem, a cemented replacement of the acetabular component was performed. At a 2-year follow-up, she had mild hip pain, but had returned fully to daily living. Our review of current published studies reveals that most inner head dislocations occurred in osteoarthritic patients. Thus, the occurrence of dislocations may be more dependent on patient selection than on failure of the bipolar prosthesis itself.
Correspondence to	Kouichi Tanaka, Department of Orthopaedic Surgery, Daini Hospital, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan