Subluxation-Induced Liner Adhesion And The Effect Of Impaction To Prevent Liner Dislocation In Ceramic Hip Arthroplasty

Description

This episode of AI Talks with Bone & Joint from Bone & Joint Research discusses the June 2026 paper by M. Uhler and colleagues on subluxation-induced liner adhesion and the effect of impaction force on preventing liner dislocation in ceramic hip arthroplasty. The hosts explain that while ceramic-on-ceramic bearings offer low wear and strong long-term performance, they can experience adhesion-related liner dislocation, a significant failure mode in total hip arthroplasty. The study compared two implant systems, Mathys SeleXys and DePuy Synthes Pinnacle, using 28 mm and 36 mm heads and different liner sizes. Researchers measured adhesion forces during head subluxation and fixation strength at assembly forces of 1 kN, 2 kN, and 4 kN using a servo-hydraulic testing machine and bovine serum as a synovial fluid surrogate. The results showed that adhesion forces could be substantial, with a maximum of 265 N, and that low impaction force, especially 1 kN, could allow adhesion forces to exceed fixation strength. At 2 kN and above, fixation strength consistently surpassed adhesion forces, suggesting this is the threshold needed to reduce dislocation risk. The discussion also highlights that implant design and head size influence adhesion and retention, with DePuy generally showing higher adhesion and fixation forces than Mathys, likely because of design differences such as taper angle. The episode concludes that surgeons should apply more than 2 kN of impaction force to improve liner stability while still avoiding excessive force that could risk ceramic fracture.

Specialties

Paper Links

https://boneandjoint.org.uk/Article/10.1302/2046-3758.156.BJR-2025-0615.R1