Hydroxyapatite in total hip arthroplasty. Our experience with a plasma spray porous titanium alloy/hydroxyapatite double-coated cementless stem

Abstract

SummaryPurpose. Total hip arthroplasty could fail due to many factors and one of the most common is the aseptic loosening. In order to achieve an effective osseointegration and reduce risk of lossening, the use of cemented implant, contact porous bearing surface and organic coating were developed. Aim of this study was to evaluate clinical and radiological mid-term outcomes of a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem applied with "plasma spray" technique and to demonstrate the possibility to use this stem in different types of femoral canals. Methods. Between January 2008 and December 2012, 240 consecutive primary total hip arthroplasties (THAs) were performed using a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem. 182 patients were examined: 136 were females (74.7%) and 46 males (25.2%); average age was 72 years old (ranging from 26 to 92 years old). For each patient, Harris Hip Scores (HHS) and Womac Scores were collected. All X-ray images were analyzed in order to demonstrate stem survival rate and subsidence. Results. Harris Hip Score was good or excellent in 85% of the cases (average 90%) and mean WOMAC score was 97.5 (ranging from 73.4 to 100). No cases of early/late infection or periprosthetic fracture were noticed, with an excellent implant survival rate (100%) in a mean period of 40 months (ranging from 24 and 84 months). 5 cases presented acute implant dislocation, 2 due to wrong cup positioning in a dysplastic acetabulum and 3 after ground level fall. Dorr classification of femoral geometry was uses and the results were: 51 type A bone, 53 type B bone and 78 type C bone. Stem subsidence over 2 mm was considered as a risk factor of future implant loosening and was evidenced in 3 female patients with type C of Dorr classification. No radiolucencies signs around the proximally coated portion of stem or proximal reabsorption were visible during the radiographic follow-up. Conclusions. Concerning the use of porous titanium alloy/hydroxyapatite double coating, this study reported an excellent implant survival rate in a mid-term period with a rate of 1,64% of subsidence in patients with type C of femoral canal but with an optimal HHS and Womac Score results. Regarding this stem, primary stability is guaranteed by trapezoid shape of proximal region and tapering in frontal plane through press-fit technique. Radiological absence of pedestal has been accepted as sign of no excessive stress transmission to distal cortex due to its tapered diaphyseal region. Thanks to the reported data, Authors can consider this double coating a valid choice with an excellent mediumterm survival and encouraging subsidence results. Further studies are needed to ensure these results can be replicated.

Use of a Plasma-Sprayed Titanium-Hydroxyapatite Femoral Stem in Hip Arthroplasty in Patients Older than 70 Years. Is Cementless Fixation a Reliable Option in the Elderly?

“…Our findings also confirmed the excellent short- to midterm outcomes reported in another previous study regarding the same prosthetic femoral implant used in younger patients [ 35 ]. Castellini et al reported no cases of stem aseptic loosening or periprosthetic fractures, with an excellent implant survival rate (100%) with stem revision for any reason after a mean follow-up of 4 years [ 35 ].…”

“…Our findings also confirmed the excellent short- to midterm outcomes reported in another previous study regarding the same prosthetic femoral implant used in younger patients [ 35 ]. Castellini et al reported no cases of stem aseptic loosening or periprosthetic fractures, with an excellent implant survival rate (100%) with stem revision for any reason after a mean follow-up of 4 years [ 35 ]. In comparison with the study conducted by Castellini et al our study included a larger cohort of implants from three large-volume centers, longer follow-up, a higher mean patient age, and a study population at a greater risk for perioperative complications, in order to investigate the safety and effectiveness of the same plasma-sprayed femoral stem in worse conditions with more serious indications.…”

Cementless Hip Implants: History and Current Status of the Issue

“…Гидроксиапатит обладает способностью не только увеличивать первичную фиксацию имплантатов за счет высокого коэффициента трения и большой прочности на сдвиг, но и усиливать минерализованный рост кости на границе с имплантатом [59]. Еще в 1990-е гг.…”

Local administration of aspirin improves osseointegration of hydroxyapatite-coated titanium implants in ovariectomized rats through activation of the Notch signaling pathway

“…1 However, the linear increase of aseptic implant loosening have become the most common complication after the third year, especially in patients with osteoporosis. 2 Lack of sex hormones, glucocorticoids application, and disuse constitute the main causes of osteoporosis. In order to solve this problem, numerous effective methods such as hydroxyapatite-coated titanium (HA-Ti) implants for enhancing osseointegration have been carried out.…”