The purpose is to determine diagnostic performances of flat panel dual energy arthrography and arthro-tomosynthesis in identification of loosening of painful hip prosthesis, taking as reference the results of surgery performed 6 months after arthrography.

Secondary purposes are:

• To describe the level of concordance of each technique with the indication for surgery
• To study inter-technique concordance with kappa coefficient
• To study the relationship between density differential between 2 acquisitions and grey level on subtraction, i.e. subtraction quality according to metal

Hip arthroplasty has become one of the most performed orthopedic procedures. Actual average lifetime of total hip prosthesis is approximately 15 years. Some complications are inevitable. Total hip prosthesis imaging, performed to search for a complication or wear, is difficult and depends on many techniques. Subtracted arthrography is a good technique but its access is limited because it needs an angiography room.

In this study patients undergo standard arthrography, dual energy arthrography, arthro-tomosynthesis and arthro-tomography.

Inclusion Criteria:

• Patients sent for arthro-tomography of painful prosthesis, without contraindications to arthrography or injection of contrast agent
• Aware and cooperative
• Signed informed consent
• Affiliation to social security

Exclusion Criteria:

• Any contraindication to arthrography or injection of contrast agent
• Pregnant or possibly pregnant women
• Patient under guardianship
• Refusal or impossibility of informed consent