Lower Revision Rates and Improved Stability With a Monoblock Ceramic Acetabular Cup

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Arthroplasty Research

Background:

• Monoblock ceramic cups with large-diameter femoral heads aim to improve range of motion and stability in total hip arthroplasty (THA).
• These features are particularly beneficial for younger, high-demand patients requiring THA.
• The DeltaMotion cup, a specific monoblock ceramic design, was evaluated for its performance.

Purpose of the Study:

• To assess the survival rate of the DeltaMotion cup.
• To identify the primary reasons for revision surgery in patients who received the DeltaMotion cup.
• To compare the performance of the DeltaMotion cup against modular bearing designs.

Main Methods:

• Analysis of Australian National Joint Replacement Registry (AOANJRR) data for primary conventional THA from 2001-2021.
• Inclusion of prostheses with ceramic/ceramic, ceramic/XLPE, metal/XLPE, or CM/XLPE bearing surfaces.
• Primary outcome: cumulative percent revision for all causes; Secondary outcomes: revision for dislocation, ceramic breakage, or noise.

Main Results:

• Out of 486,946 primary THA procedures, 4,033 used the DeltaMotion cup, and 482,913 used modular designs.
• The DeltaMotion cup demonstrated the lowest cumulative percent revision for all diagnoses compared to modular bearings.
• Significantly lower revision rates for dislocation and no revisions for squeaking were observed with the DeltaMotion cup; only 1 ceramic breakage occurred versus 175 in modular groups.

Conclusions:

• The DeltaMotion cup exhibited a low rate of all-cause revision, dislocation, ceramic breakage, and noise.
• While no longer manufactured, its performance provides insights for future monoblock ceramic cup development.
• Further follow-up of contemporary monoblock ceramic cups is necessary to confirm their suitability for active patient populations.