Influence of Geometry and Extent of Coating on Survival of Cementless Distal-Locking Revision Stems at 7 to 18 Years

We aimed to compare the long-term clinical outcomes, complications, and survival of 2 revision stems with different geometries, extents of coating, and distal-locking mechanisms.

We retrospectively compared outcomes at a minimum of 7 years following revision THA using 2 proximally coated distal-locking stems: 98 Ultime first-generation (G1) and 116 Linea second-generation (G2) stems. Ten-year Kaplan-Meier survival was assessed considering stem re-revision for any reason and for aseptic reasons. At final follow-up, Harris Hip Score and Oxford Hip Score were collected, and any thigh pain or complications were noted.

Considering re-revision for any reason, survival was 69% for G1 stems and 91% for G2 stems. Considering re-revision for aseptic reasons, survival was 77% for G1 stems and 92% for G2 stems. Re-revisions were due to fracture of 6 G1 stems but no G2 stems. Complications that required reoperation without stem or cup removal occurred in 3 of the G1 stems and 1 of the G2 stems. Compared to the G1 stems, the G2 stems resulted in better Harris Hip Score (83 vs 71, P = .001), Oxford Hip Score (22 vs 27, P = .019), less thigh pain (4% vs 39%, P < .001), and fewer nonoperated complications (9% vs 15%).

The second-generation stem had significantly better survival and clinical outcomes than the first-generation stem. The differences in survival and clinical outcomes could be attributed to the larger coated surface of the G2 stem and to the fact that the G1 stem was originally intended as a temporary implant to be followed by de-escalation.