Acetabular cup failure after total hip replacement

The major complications following total hip replacement (THA) are implant loosening, dislocation, instability, fracture and infection. It is hypothesized that vibration, in the range of the resonance frequencies, may cause pain, bone degeneration and fracture. A further understanding of the physical response resulting from impact during femoral head sliding may lead to valuable insight pertaining to THA failure. Therefore, the first objective of this present study was to determine if frequencies propagating through the hip joint near resonant frequencies may lead to wear or loosening of the components. Recently, studies found that femoral head sliding, often referred to as hip separation, between the acetabulum cup and the femoral head does occur, which may also play a role in complications observed with THA today, but a the effects of hip separation and the causes of its occurrence has not been studied as jet. Therefore, the second objective of this study was to determine if a sound sensor, externally attached, could be used to correlate impact loading sounds from femoral head sliding in the acetabular cup. Additional objective of this study was to develop a mathematical model that better simulates the in vivo loading conditions of total hip replacement patients using in vivo fluoroscopic and ground reaction data as input.

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Obesity Does Not Affect The Accuracy of Acetabular Cup Implantation in Total Hip Replacement

The Internet Journal of Orthopedic Surgery ◽

10.5580/367 ◽

2007 ◽

Vol 6 (1) ◽

Keyword(s):

Total Hip Replacement ◽

Hip Replacement ◽

Acetabular Cup ◽

Total Hip

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Dislocation of a dual mobility total hip replacement following fracture of the polyethylene liner

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-15-01-0016 ◽

2016 ◽

Vol 29 (03) ◽

pp. 259-264

Author(s):

Pierre Guillaumot ◽

Jean-Luc Chancrin ◽

Bertrand Vedrine

Keyword(s):

Total Hip Replacement ◽

Hip Replacement ◽

Hip Prosthesis ◽

Polyethylene Liner ◽

Acetabular Cup ◽

Dual Mobility ◽

Total Hip ◽

Initial Surgery ◽

Acute Rupture ◽

Cemented Cup

SummaryAn eight-year-old male English Setter was referred for management of a dislocation of a cemented dual mobility canine total hip prosthesis that occurred four months after the initial surgery. Revision surgery showed that the dislocation was associated with fracture of the ultra-high molecular weight polyethylene liner. The dislocation was successfully reduced after replacing the liner. A dual mobility acetabular component is composed of a mobile polyethylene liner inside a metallic cemented cup. Chronic wear of the components of a canine dual mobility total hip replacement has not been described previously. The use of this type of implant is fairly recent and limited long term follow-up of the implanted cases may be the explanation. Acute rupture of a polyethylene liner has never been described in humans, the only case of rupture of a polyethylene liner occurred 10 years after implantation. The case presented here of rupture of the polyethylene liner of a dual mobility total hip replacement is a hitherto unreported failure mode in this model of acetabular cup in the dog.

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