Clinical and radiographic outcomes of a trabecular titanium™ acetabular component in hip arthroplasty: results at minimum 5 years follow-up

Abstract

BackgroundAim of this prospective study was to evaluate mid-term clinical and radiographic outcomes in total hip arthroplasty using an acetabular cup made of an innovative biomaterial, Trabecular Titanium™, whose highly porous structure and mechanical properties have been designed to mimic those of the natural bone, thus promoting a more physiological load transfer and a more durable fixation.MethodsBetween September 2007 and November 2009, 134 total hip replacements and eight revisions were carried out using DELTA-TT primary cups (Lima Corporate, Villanova di San Daniele del Friuli, Italy) in 133 consecutive patients. Mean age was 57.5 ± 14.7 SD (18–92) years. Diagnosis was primarily hip osteoarthritis in 85 (63 %) cases, developmental dysplasia of the hip (DDH) in 24 (18 %) and hip avascular necrosis (AVN) in 10 (7 %). All the revision procedures were due to aseptic loosening of the original implant. Approval of the Institutional Review Board of the IRCCS Policlinico San Matteo in Pavia was obtained for this study.ResultsMean follow-up was 72.7 ± 7.9 SD (60–86) months. Average Harris Hip Score (HHS) significantly increased from 44.2 ± 5.4 SD (35–52) preoperatively to 95.9 ± 3.5 SD (88–100) at the last follow-up. No major post-operative complications were observed. 99.3 % of the acetabular components were radiographically stable at the last follow-up, without any radiolucent lines, sclerotic areas or periprosthetic osteolysis. Kaplan-Meier survival rate was 99.3 % at 5 years (95 % confidence interval).ConclusionsThis first account on the mid-term clinical performance of the DELTA-TT cup shows primary and secondary stability, thus representing an optimal solution for patients with high demands or affected by severe hip conditions.

Use of Trabecular Titanium Implants for Primary Hip Arthroplasty

“…However, it needs to be borne in mind that the study patients scored very low on the HHS at baseline. For instance, Perticarini et al, who used trabecular titanium implants and impaction grafting in primary hip arthroplasty, showed a superior final outcome according to HHS but the study group also had considerably better baseline scores [25]. The above paper described an improvement from the average of 44.2 points to 93.9 points, while in the present study patients' baseline score was 22.1 points and it reached an average of 64.35 points after the surgery.…”

“…Dla przykładu w pracy Per ticarini i wsp. wykazano wprawdzie lepszy końcowy wynik w skali Harris'a, stosując podczas pier wot nych zabiegów implanty z porowatego tytanu oraz im paction grafting, ale grupa chorych włączonych do badania miała znacznie lepsze wyniki przed wykonaniem zabiegu [25]. W cytowanej pracy ob ser wowano poprawę ze średnio 44.2 pkt do 95.9 pkt.…”

Additive manufactured push‐fit implant fixation with screw‐strength pull out

“…Our study did not investigate if fretting could occur between the struts and the cage, nor did it evaluate methodology to clean implants or mitigate strut breakages. Cleaning methods have already been developed by industry as additive manufactured implants utilizing porous structures have already been implanted in patients worldwide 12, 13, 21. Strut breakage occurred during testing, though was very design dependent: Some variants lost nearly all their struts during pull out, while other designs remained intact.…”

“…Modularity between screw fixation bases and other components8 can lead to problems with intraoperative assembly and fretting/corrosion wear; the subsequent soft tissue reactions to the resulting metal debris can cause a severe revision burden 11. Press‐fit fixations enable non‐axisymmetric/multiple fixation features and are frequently used for arthroplasty components 12, 13, 14, 15. However, they provide lower initial fixation strength than screws (only around 50–150 N of pull‐out force, an order of magnitude less than a screw equivalent) 5, 6, 9, 16, 17.…”

“…AM technology has been used for dental implants,20 mass market joint replacement designs,12, 13 and custom implants for the treatment of osteosarcoma 21. For implant fixation, a big draw of AM technology is the ability to create porous structures that bone can grow into, allowing improvement in long‐term fixation; consequently porous structures have been extensively researched 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32.…”