Taper Failure After Large-Diameter Metal-on-Metal Total Hip Arthroplasty

Abstract

The use of metal-on-metal bearing surfaces for total hip arthroplasty increased dramatically in the past decade for a variety of reasons, including the advantage of using larger-diameter femoral heads to reduce instability. However, recent research suggesting negative outcomes and high failure rates associated with some of these implants has decreased their use. Further, the use of larger-diameter femoral heads on relatively small femoral neck tapers has caused concern about localized corrosion at this junction, particularly with varus femoral alignment and longer femoral neck and head lengths. Although the advent of modular components offers the surgeon greater intraoperative flexibility, this modularity may prove to be a weak link when coupled with large-diameter femoral heads. This report describes a patient with a history of bilateral metal-on-metal total hip arthroplasty complicated by failure of the right hip as a result of fretting and mechanically assisted crevice corrosion. Notching of the femoral neck and head dissociation occurred 10 years after the primary procedure. The authors describe the patient's presenting symptoms, the possible etiology of the catastrophic failure, and the method of treatment and provide a brief review of metal-on-metal implants that may shed some light on the complications in this case. [Orthopedics.2016; 39(5):e984-e987.].

A review of the bio-tribology of medical devices

“…The design and manufacturing parameters of the modular interface can also affect the fretting motion. A large diameter of the metal-on-metal bearing surface often results in more serious fretting corrosion [52]. The effects of taper shape on fretting corrosion were studied by Tan et al [53].…”

“…Besides, the bearing surface between the femoral head and the acetabular cup can also affect the fretting corrosion at the modular interface, and the friction torque at the bearing surface plays an important role in this process. Under adverse conditions, metal-on-metal bearing surfaces with large diameters can produce a high coefficient of friction, leading to severe fretting corrosion [3,52]. The weight of the patient can directly affect the fretting corrosion damage at the cone neck assembly [56].…”

Retention of metals in periprosthetic tissues of patients with metal-on-metal total hip arthroplasty is reflected in the synovial fluid to blood cobalt transfer ratio in the presence of a pseudotumour

“…The common denominator for these studies is that adverse reactions are found more often than anticipated, and clinical manifestations vary [13][14][15]. The awareness of implant reactions might partially explain the rise, but there is substantial evidence [16][17][18][19][20] that this is a real clinical phenomenon, although some of these reactions can be asymptomatic.…”