Survivorship of Monoblock Trabecular Metal Cups in Primary THA

Abstract

Monoblock trabecular metal cups are made of a novel porous material intended to enhance ingrowth and improve fixation. We prospectively followed 223 consecutive patients with 245 trabecular metal acetabular cups implanted during primary total hip arthroplasties to determine the overall survivorship of the implant, and any association of survivorship to primary diagnosis and age, and to determine the fate of polar gaps and cysts. Minimum followup was 36 months (mean, 60 months; range, 36-112 months). Patients were assessed with the Harris Hip score and the Oxford questionnaire and radiographically with standardized serial radiographs. At last followup, all cups were radiographically stable with no evidence of migration or progressive radiolucencies. The survivorship with reoperation as the end point was estimated at 98.75% with a 95% confidence interval. Three reoperations occurred during the first 36 months. The Harris hip score increased from 48 to 94 and the Oxford score was 16.4 at the last examination. We observed no difference in terms of survivorship among patients with osteoarthritis, osteonecrosis, or hip dysplasia. Seven of 14 (50%) osteoarthritis cysts and 10 of 33 (33.3%) polar gaps detected on postoperative radiographs decreased or filled, whereas none of the remainder deteriorated with time. Our midterm results suggest this implant may enhance fixation, but long-term followup is needed to confirm our findings.

Trabecular Metal™ Cups for Acetabular Defects With 50% or Less Host Bone Contact

“…Each author certifies that his or her institution has approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. demonstrated encouraging revisions rates of 0% to 6% for mechanical loosening for both primary and revision hip arthroplasty at an average of 3 to 5 years [3,6,13,14,21,22]. Utilizing these new TM cups, it is quite possible, when reasonable primary stability can be obtained and reinforced by effective screw fixation, the need for more than 50% host bone contact may now be reduced.…”

Early Clinical Outcomes with a 3-D Porous Titanium Acetabular Cup

“…Porous Tantalum such as Trabecular Metal (Zimmer Biomet, Warsaw, IN) was introduced since late-1990s and both short-term and mid-term outcomes with this prosthesis were excellent [10]- [12]. On the other hand, porous titanium or porous coating titanium such as Gription (Deputy, Warsaw, IN), Tritanium (Stryker, Mahwah, NJ) and Stiktite (Smith and Nephew, Memphis, TN) as well as the current prosthesis Regenerex have been used since mid-2000s [13] [14].…”

Osteonecrosis of the femoral head

“…Although, cup failure is more common than stem failure even in non-osteonecrotic THRs, Titanium or Tantalum highly-porous acetabular cups have shown excellent survivorship in non-osteonecrotic hips at short-term follow-up. [47][48][49] For example, Naziri et al 48 evaluated 288 cementless THRs performed using a highly-porous titanium acetabular cup in 252 patients and reported 100% survivorship (excluding infection) at a mean follow-up of 36 months (24 to 56). Although longer-term studies are necessary to evaluate these acetabular components in the setting of osteonecrosis, promising stem and cup survivorships appears to be achievable.…”