Low BMD affects initial stability and delays stem osseointegration in cementless total hip arthroplasty in women

Abstract

Background and purpose Immediate implant stability is a key factor for success in cementless total hip arthroplasty (THA). Low bone mineral density (BMD) and age-related geometric changes of the proximal femur may jeopardize initial stability and osseointegration. We compared migration of hydroxyapatite-coated femoral stems in women with or without low systemic BMD.Patients and methods 61 female patients with hip osteoarthritis were treated with cementless THA with anatomically designed hydroxyapatite-coated femoral stems and ceramic-ceramic bearing surfaces (ABG-II). Of the 39 eligible patients between the ages of 41 and 78 years, 12 had normal systemic BMD and 27 had osteopenia or osteoporosis. According to the Dorr classification, 21 had type A bone and 18 had type B. Translational and rotational migration of the stems was evaluated with radiostereometric analysis (RSA) up to 2 years after surgery.Results Patients with low systemic BMD showed higher subsidence of the femoral stem during the first 3 months after surgery than did those with normal BMD (difference = 0.6, 95% CI: 0.1–1.1; p = 0.03). Low systemic BMD (odds ratio (OR) = 0.1, CI: 0.006–1.0; p = 0.02), low local hip BMD (OR = 0.3, CI: 0.1–0.7; p = 0.005) and ageing (OR = 1.1, CI: 1.0–1.2; p = 0.02) were risk factors for delayed translational stability. Ageing and low canal flare index were risk factors for delayed rotational stabilization (OR = 3, CI: 1.1–9; p = 0.04 and OR = 1.1, CI: 1.0–1.2; p = 0.02, respectively). Harris hip score and WOMAC score were similar in patients with normal systemic BMD and low systemic BMD.Interpretation Low BMD, changes in intraosseous dimensions of the proximal femur, and ageing adversely affected initial stability and delayed osseointegration of cementless stems in women.

Densitometric evaluation of bone remodelling around Trabecular Metal Primary stem: a 24-month follow-up

“…On the contrary, patients with BMI \30 showed a different BMD pattern: in ROI1, early bone resorption with a following slight recovery was recorded; in ROI7, pronounced bone resorption within 6 months did not show any considerable new bone formation around the implant. However, ROI7 is known to be the region most affected by bone resorption caused by altered load transmission, especially when a standard femoral stem is implanted [19]. In this region, a statistical significance was observed at 24 months (p = 0.042), while in ROI1, a statistical significance was observed at 6 months (p = 0.05).…”

“…Periprosthetic bone resorption is a physiological reaction to the new biomechanical configuration and is strongly influenced by preoperative bone quality [19]; in all the groups studied, we observed a bone enhancement, which is recognizable also in patients with altered bone quality.…”

Is Model-based Radiostereometric Analysis Suitable for Clinical Trials of a Cementless Tapered Wedge Femoral Stem?

“…In both measurements of MBRSA and UmRSA 1 , the center of the femoral head was used as an additional marker to obtain better scatter of the stem segment and to increase reliability of the measurements. The setup for the clinical RSA imaging of trial patients, originally standardized in previous phantom [17] and clinical [1] studies, did not differ from that of the phantom study.…”

Mechanical properties of a cemented porous implant interface

“…In vivo, there are many factors that influence the stability of a bone/cement interface including lavage, bone density, hemostasis, the cement application technique, the consistency of the cement, and the heat created during cement application (Askew et al 1984, Benjamin et al 1987, Bannister and Miles 1988, Breusch and Malchau 2005, Bitsch et al 2010, 2011, Aro et al 2012). In vitro, most of these factors do not apply—with the exception of those related to the cement.…”