Metal-on-metal hip surface replacement: the routine use is not justified

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Clinical outcomes research

Background:

• Metal-on-metal hip resurfacing (MoMHR) gained popularity for hip osteoarthritis, with proponents citing improved survival and function over total hip replacement (THR).
• Concerns have resurfaced regarding the long-term safety and efficacy of MoMHR procedures.
• The procedure involves a metal cap placed on the femoral head and a metal socket inserted into the pelvis.

Purpose of the Study:

• To critically evaluate the purported advantages of MoMHR compared to conventional THR.
• To investigate the occurrence of new and unanticipated complications associated with MoMHR.
• To determine if the routine use of MoMHR for hip osteoarthritis is clinically justified.

Main Methods:

• Review of existing literature and clinical data on MoMHR and THR outcomes.
• Analysis of reported complications, including pseudotumor formation.
• Comparative assessment of survival rates, revision procedures, and functional outcomes.

Main Results:

• Evidence supporting superior survival rates for MoMHR over THR was not consistently realized.
• MoMHR procedures did not demonstrate significant advantages in terms of invasiveness or ease of revision.
• Serious complications, such as pseudotumors, have been increasingly associated with MoMHR, raising safety concerns.

Conclusions:

• The proposed benefits of MoMHR, including enhanced survival and functional outcomes, are not adequately supported by current evidence.
• The emergence of severe complications like pseudotumors negates the perceived advantages of MoMHR.
• Routine use of metal-on-metal hip resurfacing for osteoarthritis is not justified due to unproven benefits and significant risks.