Using MRI To Detect Soft Tissue Reactions And Implant Integration As Related To Implant Modularity

The Ability Of MRI To Detect Adverse Local Tissue Reaction And Implant Integration As A Function Of Hip Implant Modularity

Patients with a total hip replacement may require early revision surgery due to an adverse local tissue reaction or bone resorption that occurs due to wear debris released from the implant. MRI provides a non-invasive biomarker for clinicians and surgeons to detect early adverse synovial reactions which may exist in the absence of clinical symptoms, thus imparting essential information for clinical management. This study will address two of the most commons causes of hip implant failure, including adverse local tissue reaction in implants not traditionally associated with adverse tissue reactions, as well as the presence of aseptic loosening and loss of implant-bone integration.

Total hip arthroplasty (THA) has been successful in achieving pain reduction, but recent concerns have been raised regarding the development of adverse local tissue reactions (ALTRs). Our group has previously found that: 1) Magnetic resonance imaging (MRI) can detect and distinguish wear debris from THA; 2) MRI is sensitive to ALTR damage from different articulating surfaces; and 3) variable host-mediated response to wear debris mounts distinct morphologic patterns on MRI. There is continued interest in the evaluation of soft tissues near THAs as traditional THA designs, including metal-on-polyethylene (MOP) and ceramic-on-polyethylene (COP) bearing surfaces, have recently been implicated in ALTRs. It is believed that fretting and corrosion at the head-neck junction is responsible for ALTRs, secondary to flexural rigidity and other implant mechanical features. If a greater prevalence of ALTR is found in components with more flexible connections, this could drive the practice of THA to stiffer connections.

In this study, we will evaluate two important causes of implant failure: (1) in designs not traditionally associated with ALTRs such as metal-on-polyethylene (MOP) and ceramic-on-polyethylene (COP) we will assess patients indicated for revision THA surgery with MRI and correlate the imaging metrics to targeted biopsy retrieval obtained at the time of revision (including the trunnion), the extent of tissue damage documented at surgery, and implant retrieval analysis of the neck trunnion, including flexural rigidity analysis; and (2) to longitudinally assess implant integration using qualitative MRI evaluation of the bone-implant interface as well as quantitative MRI techniques, T2 mapping and T2* mapping using MAVRIC-UTE, to evaluate relaxometry at the interface.

Inclusion Criteria:

Cohort #1:

1. Have a total hip replacement with a ceramic component undergoing revision for any reason, including recurrent dislocation.
2. Have a metal-on-polyethylene total hip replacement and have repeated dislocation, or
3. Have a metal-on-polyethylene total hip replacement greater than 1 year old, or
4. Have an infected total hip replacement (any surface bearing)

Cohort #2:

1. Have a total hip replacement with a ceramic component.
2. Have a metal-on-polyethylene total hip replacement.
3. Have your original or revised total hip replacement.

Exclusion Criteria:

Cohort #1:

1. Have occupational exposure to cobalt or chromium
2. Presence of MOM or recalled implant
3. Have had a prior revision of your total hip
4. Standard contra-indications to MRI

Cohort #2:

1. Have occupational exposure to cobalt or chromium.
2. Have cemented components.
3. Presence of a metal-on-metal or recalled implant.
4. Standard contra-indications to MRI.