Hemispheric cups do not reproduce acetabular rim morphology

Background Iliopsoas impingement is a recurrent complication following THA, caused by muscle friction against a protrusive prosthetic cup.This study was designed to quantify the dimensional variations in acetabular rim proiles, with particular regard to the iliopubic valley, in order to suggest means to prevent iliopsoas impingement. Material and methods 34 cadaver pelvises were analyzed using a hip navigation system.The morphometric data were processed to plot proiles of all acetabular rims with particular regard to the shape and depth of the psoas valley. Results The acetabular rim is an asymmetric succession of 3 peaks and 3 troughs.The psoas valley is a salient feature in most pelvises and there is only a weak correlation between its depth (mean 3.8 mm, SD 2.0) and acetabular diameter, anteversion, or inclination. Interpretation It would be dificult to obviate the anterior overlap of the acetabulum using a hemispheric cup, a fortiori in certain morphotypes, without compromising range of motion or risk of dislocation.The solution for prevention of iliopsoas impingement would be to adapt cup design to acetabular anatomy, which may require different implants for the right and left sides, and hence a doubled inventory.

[1]  R Roy-Camille,et al.  Dynamic anatomy of the acetabulum: an experimental approach and surgical implications , 2005, Surgical and Radiologic Anatomy.

[2]  K. Herrlin,et al.  Ileopectineal bursitis following total hip replacement. , 1984, Acta orthopaedica Scandinavica.

[3]  J. Lazennec,et al.  Variations of caudal, central, and cranial acetabular anteversion according to the tilt of the pelvis , 2004, Surgical and Radiologic Anatomy.

[4]  D. Berry,et al.  Anterior iliopsoas impingement after total hip arthroplasty. , 1995, The Journal of arthroplasty.

[5]  L. Strayer.  Embryology of he human hip joint. , 1971, Clinical orthopaedics and related research.

[6]  A. Prassl,et al.  The frontal pelvic plane provides a valid reference system for implantation of the acetabular cup: Spatial orientation of the pelvis in different positions , 2005, Acta orthopaedica.

[7]  A. Duquennoy,et al.  [Anterior iliopsoas impingement after total hip arthroplasty: diagnosis and conservative treatment in 9 cases]. , 2001, Revue de chirurgie orthopedique et reparatrice de l'appareil moteur.

[8]  P Benum,et al.  Pelvic Inclination and Spatial Orientation of the Acetabulum , 1990, Acta radiologica.

[9]  T. Miller,et al.  Sonographically guided injection of anesthetic for iliopsoas tendinopathy after total hip arthroplasty , 2004, Journal of clinical ultrasound : JCU.

[10]  P. Taourel,et al.  Iliopsoas Impingement on the Acetabular Component: Radiologic and Computed Tomography Findings of a Rare Hip Prosthesis Complication in Eight Cases , 2003, Journal of computer assisted tomography.

[11]  C. Gupte,et al.  Iliopsoas bursitis following total hip replacement , 2004, Archives of Orthopaedic and Trauma Surgery.

[12]  H. Uhthoff,et al.  [Embryology of the human hip]. , 1997, Der Orthopade.

[13]  J. Witvoet,et al.  [Conflict between psoas and total hip prosthesis]. , 1991, Revue du rhumatisme et des maladies osteo-articulaires.

[14]  H. Uhthoff,et al.  Embryology of the human hip joint , 1997 .

[15]  L. Béguin,et al.  [Iliopsoas impingement in 12 patients with a total hip arthroplasty]. , 2001, Revue de chirurgie orthopedique et reparatrice de l'appareil moteur.

[16]  X. Montet,et al.  Ultrasound diagnosis of anterior iliopsoas impingement in total hip replacement , 2004, Skeletal Radiology.

[17]  W. Capello,et al.  Morphologic Features of the Acetabulum and Femur: Anteversion Angle and Implant Positioning , 2001, Clinical orthopaedics and related research.