Global diversity in bearings in primary THA

Abstract

Choice of articulating materials, head size and the design of the articulation will become decisive for the long-term performance of a total hip arthroplasty (THA) and especially in terms of risk for dislocation and wear-related problems. Here we account for common alternatives based on available studies and the evidence that can be derived from them. Metal or ceramic femoral heads articulating against a liner or cup made of highly cross-linked polyethylene and ceramic-on-ceramic articulations have about similar risk for complications leading to revision, whereas the performance of metal-on-metal articulations, especially with use of big heads, is inferior. The clinical significance of problems related to ceramic-on-ceramic articulations such as squeaking remains unclear. With use of current technology ceramic fractures are rare. Large femoral heads have the potential to increase the range of hip movement before impingement occurs and are therefore expected to reduce dislocation rates. On the other hand, issues related to bearing wear, corrosion at the taper-trunnion junction and groin pain may arise with larger heads and jeopardize the longevity of THA. Based on current knowledge, 32-mm heads seem to be optimal for metal-on-polyethylene bearings. Patients with ceramic-on-ceramic bearings may benefit from even larger heads such as 36 or 40 mm, but so far there are no long-term reports that confirm the safety of bearings larger than 36 mm. Assessment of lipped liners is difficult because randomized studies are lacking, but retrospective clinical studies and registry data seem to indicate that this liner modification will reduce the rate of dislocation or revision due to dislocation without clear evidence of clinically obvious problems due to neck-liner impingement. The majority of studies support the view that constrained liners and dual mobility cups (DMC) will reduce the risk of revision due to dislocation both in primary and revision THA, the latter gaining increasing popularity in some countries. Both these devices suffer from implant-specific problems, which seem to be more common for the constrained liner designs. The majority of studies of these implants suffer from various methodological problems, not least selection bias, which calls for randomized studies preferably in a multi-centre setting to obtain sufficient power. In the 2020s, the orthopaedic profession should place more effort on such studies, as has already been achieved within other medical specialties, to improve the level of evidence in the choice of articulation when performing one of the most common in-hospital surgical procedures in Europe. Cite this article: EFORT Open Rev 2020;5:763-775. DOI: 10.1302/2058-5241.5.200002

Comparison of Ceramic-on-Ceramic vs. Ceramic-on-Polyethylene for Primary Total Hip Arthroplasty: A Meta-Analysis of 15 Randomized Trials

“…Considering the metal debris from the taper-trunnion junction in hip prostheses has been widely recognized ( 34 ), it is reasonable to speculate the COC with a lower wear rate can produce a considerable number of metal debris from the taper-trunnion junction, which may compromise the advantage of COC on wear rate. More importantly, except for the bearing surfaces, other reasons such as the diameter of the femoral head ( 4 ), the position of the acetabular cup ( 35 ), and the prosthesis from different manufacturers ( 36 ) can also affect the final result.…”

“…Up to date, more than 1 million THAs have been performed every year worldwide and the number in the United States alone was more than 5,00,000 ( 3 ). Despite the tremendous advances in prosthetic design and materials over the past decades, heated debates with respect to the choice of bearing surfaces remain controversial, especially about ceramic-on-ceramic (COC) components and ceramic-on-polyethylene (COP) components, both of which are most commonly used in clinical work ( 4 ). Since ceramic material was first introduced in THA by Boutin 50 years ago, it has attracted the attention of people owing to the typical feature of hardness and wettability with high resistance against wear ( 5 ).…”

Advances and innovations in total hip arthroplasty

“…Larger femoral heads have increasingly been used in THA during the past decade, as they increase the range of hip movement before impingement and consequently reduce dislocation rates [ 95 ]. Thirty-two millimeter and 36 mm are the most commonly used femoral head sizes, as reported by several arthroplasty registries [ 96 – 98 ].…”

Outcomes of Ceramic Composite in Total Hip Replacement Bearings: A Single-Center Series

“…Avascular necrosis (AVN) or osteonecrosis of the femoral head is caused by a lack of blood supply in the region; in the later stages of the disease, bone is reabsorbed and the epiphysis collapses: it is obvious that hip replacement with THA, which provides immediate pain relief and excellent functional outcomes, should be considered the preferred treatment. Nevertheless, previous reports have underlined that avascular necrosis represents a risk factor of biomechanical failure of implants [24,25] due to the pathogenesis of periprosthetic osteolysis, strictly connected to wear debris of polyethylene. Such a cause of failure of a THA remains one of the most prevalent in young and active patients, and thus alternative hard materials have been developed as bearing surfaces in clinical practice to reduce the detrimental effects of wear on prosthesis survival.…”