Different loss of BMD using uncemented press-fit and whole polyethylene cups fixed with cement: Repeated DXA studies in 96 hips randomized to 3 types of fixation

Abstract

Background In cemented THA, aseptic loosening of the cup is more common than loosening of the stem, while periprosthetic osteolysis of the socket resulting in difficult reconstruction problems has emerged as the most significant problem with cementless cup fixation.Patients and methods 90 patients (96 hips) scheduled for THA were stratified in three groups according to the method of fixation of the acetabular component: acrylic bone cement with fluoride (Cemex-F), porous-coated press-fit cup with ceramic coating (Trilogy, uncemented) and acrylic cement with gentamicin (Palacos). All patients received the Spectron EF stem. Acetabular bone mineral density was measured with dual-energy X-ray absorptiometry (DXA) 1 week postoperatively, and after 12 and 24 months. The periprosthetic BMD was evaluated in 5 ROIs positioned around the acetabular component.Results In the uncemented sockets, the BMD had decreased proximally and medially to the cup after 2 years. The difference was significant in the proximal region as compared to the control group (Palacos). No difference was noted between the 2 groups with cemented components after 2 years. Stepwise linear regression analysis showed that loss of periprosthetic BMD in the proximal high-pressure region after 2 years increased with higher postoperative BMD and when the uncemented design had been used. Interpretation Contrary to previous studies of cemented stems, the use of fluoride cement did not influence the periprosthetic BMD 2 years after the examination. Increased loss of BMD with use of uncemented press-fit cups in the region in which osteolytic lesions are commonly found suggests that stress shielding may initiate the development of this complication. Longer

Highly Crosslinked Polyethylene Does Not Reduce Aseptic Loosening in Cemented THA 10-year Findings of a Randomized Study

“…Notably, overall bone density increased medially and decreased below the cup, indicating central load bearing. Patterns of bone loss around cemented cups vary in the literature probably due to design differences and short followup times [9,41]. Femoral bone loss was more pronounced proximally than distally, as previously reported [8,55].…”

Retroacetabular Stress-shielding in THA

“…However, he reported problems identifying the threshold between bone and implant in cases with strong cortical bone. Digas et al [2] assessed acetabular BD with dual-energy xray absorptiometry in three cohorts of patients with press-fit cups or cemented cups using two different types of bone cement. The authors reported that, after 2 years, loss of periprosthetic BD in the region of interest above the cup increased with higher postoperative BD and when the uncemented design had been used.…”

Modes of periacetabular load transfer to cortical and cancellous bone after cemented versus uncemented total hip arthroplasty: A prospective study using computed tomography‐assisted osteodensitometry

“…A recently very well-designed DXA based study by Digas et al 15 has analyzed BD in five regions of interest (ROI) around a press-fit cup 2 years after index operation. Two ROIs were placed proximally to the cup and one medially to the cup.…”

“…1 In the last century increasing knowledge of load transfer mechanisms and stress distribution patterns after total hip replacements was provided. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Most of these studies have focussed on stress shielding mechanisms after femoral stem implantation. [2][3][4][5][6]10 The most common technique to study bone density (BD) changes is dual X-ray absorptiometry (DXA), which is a reproducible two-dimensional measurement technique.…”

“…[2][3][4][5][6]10 The most common technique to study bone density (BD) changes is dual X-ray absorptiometry (DXA), which is a reproducible two-dimensional measurement technique. [2][3][4][5][6][7]11,[15][16][17] To allow a differentiated three-dimensional analysis of cortical and cancellous bone structures after THA in vivo we have introduced a novel method of CT-assisted osteodensitometry. 9,10,13,14 In a previous study we have provided clear evidences for the reproducibility and validity of our method.…”