• 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

• The use of larger femoral head size in total hip arthroplasty (THA) has increased during the past decade; 32 mm and 36 mm are the most commonly used femoral head sizes, as reported by several arthroplasty registries.

• The use of large femoral heads seems to be a trade-off between increased stability and decreased THA survivorship.

• We reviewed the literature, mainly focussing on the past 5 years, identifying benefits and complications associated with the trend of using larger femoral heads in THA.

• We found that there is no benefit in hip range of movement or hip function when head sizes > 36 mm are used.

• The risk of revision due to dislocation is lower for 36 mm or larger bearings compared with 28 mm or smaller and probably even with 32 mm.

• Volumetric wear and frictional torque are increased in bearings bigger than 32 mm compared with 32 mm or smaller in metal-on-cross-linked polyethylene (MoXLPE) THA, but not in ceramic-on-XLPE (CoXLPE).

• Long-term THA survivorship is improved for 32 mm MoXLPE bearings compared with both larger and smaller ones.

• We recommend a 32 mm femoral head if MoXLPE bearings are used. In hips operated on with larger bearings the use of ceramic heads on XLPE appears to be safer.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170061.