High prevalence and undertreatment of osteoporosis in elderly patients undergoing total hip arthroplasty

Abstract

We detected a high prevalence of low bone mineral density assessed by DXA in 268 elderly patients with end-stage osteoarthritis scheduled for total hip arthroplasty (18% osteoporosis, 41% osteopenia). Therefore, and due to the identified concomitant undertreatment, routine DXA measurements should be considered in elderly patients prior to surgery.

Introduction: Bone quality represents a decisive factor for osseointegration, durability, and complications of an implanted prosthesis. Although the risk of osteoporosis increases with age and the assessment of bone mineral density (BMD) prior to total hip arthroplasty (THA) is recommended in elderly patients, a systematic, unbiased analysis of such patients is not available in the literature.

Methods: In this retrospective study, we examined 268 elderly patients (age ≥70 years) who underwent dual-energy X-ray absorptiometry (DXA) within 3 months prior to primary THA. Demographics, medical history, radiographic OA grade, and stem fixation method (i.e., cemented or cementless) were obtained.

Results: In total, 153 (57%) cemented and 115 (43%) cementless stem fixations during THA were performed. Forty-nine patients (18%) were diagnosed with osteoporosis (T-score ≤-2.5), 110 patients (41%) with osteopenia (T-score ≤-1.0), and 109 patients (41%) with normal BMD (T-score >-1.0). Importantly, 36/49 patients (73%) with osteoporosis were not diagnosed before, resulting in a relevant undertreatment. Female sex and low body mass index (BMI) were the main factors negatively influencing the bone mineral density (BMD).

Conclusions: Due to a high incidence of undiagnosed and untreated osteoporosis in elderly patients with potential effects on the success of osseointegration as well as other clinical outcomes, DXA measurements should be included in the clinical routine for these patients prior to THA.

Keywords: Arthroplasty; Bone mineral density; DXA; Osteoarthritis; Osteoporosis.

Fig. 1

Overview of the study collective and DXA results in THA patients aged ≥ 70 years. a Representative preoperative radiograph (right hip AP) of an OA patient included in this study. b Postoperative radiographs (right hip AP) of a cemented and a cementless THA. c Sex distribution of the study population. d Pie charts showing DXA results and categorization in osteoporosis, osteopenia, or bone mineral density within the reference range based on the T-score_min. A detailed description of the osteoporosis patients concerning e an existing diagnosis of osteoporosis, f the current supplementation of vitamin D, and the g application of a bone-specific therapy

Fig. 2

Influencing factors on BMD values at the hip. a In the patient collective of OA patients ≥70 years, significantly lower T-scores at the hip could be revealed in females compared to males (Mann-Whitney U test). b Furthermore, age (years) showed a weak negative association with the T-score at the hip (linear regression). c A moderate positive association was detected between BMI and T-score at the hip (linear regression). d T-scores of the affected hip were not different between the different OA grades determined by the Kellgren-Lawrence scores (Kruskal-Wallis test). ****p<0.0001