Good stability of a cementless, anatomically designed femoral stem in aging women: a 9-year RSA study of 32 patients

Abstract

Background and purpose — We previously reported a transient, bone mineral density (BMD)-dependent early migration of anatomically designed hydroxyapatite-coated femoral stems with ceramic–ceramic bearing surfaces (ABG-II) in aging osteoarthritic women undergoing cementless total hip arthroplasty. To evaluate the clinical significance of the finding, we performed a follow-up study for repeated radiostereometric analysis (RSA) 9 years after surgery.Patients and methods — Of the 53 female patients examined at 2 years post-surgery in the original study, 32 were able to undergo repeated RSA of femoral stem migration at a median of 9 years (7.8–9.3) after surgery. Standard hip radiographs were obtained, and the subjects completed the Harris Hip Score and Western Ontario and McMaster Universities Osteoarthritis Index outcome questionnaires.Results — Paired comparisons revealed no statistically significant migration of the femoral stems between 2 and 9 years post-surgery. 1 patient exhibited minor but progressive RSA stem migration. All radiographs exhibited uniform stem osseointegration. No stem was revised for mechanical loosening. The clinical outcome scores were similar between 2 and 9 years post-surgery.Interpretation — Despite the BMD-related early migration observed during the first 3 postoperative months, the anatomically designed femoral stems in aging women are osseointegrated, as evaluated by RSA and radiographs, and exhibit good clinical function at 9 years.

Effect of Denosumab on Femoral Periprosthetic BMD and Early Femoral Stem Subsidence in Postmenopausal Women Undergoing Cementless Total Hip Arthroplasty

“…(64) The current trial included gait analysis and the assessment of walking activity because the amount of physiological loading is one of the potential confounding patient-related factors dictating the final amount of stem migration. Although the limited initial migration does not seem to prevent osseointegration, (15,16) continuous subsidence 6 to 12 months after the operation could indicate increased risk of future revision. (65) However, there are not enough published results to draw definite conclusions.…”

“…Initial subsidence and rotation does not ultimately prevent stem osseointegration, (14)(15)(16) and osseointegrated stems do not develop late mechanical loosening. (15) Bisphosphonates have failed to reduce femoral stem subsidence in various patient populations, (17,18) including postmenopausal women. (16) Postmenopausal women with low BMD also suffer from aggravated early periprosthetic bone resorption, (19) which may appear radiographically as late bone loss around the osseointegrated femoral stems.…”

“…However, postmenopausal women with low bone mineral density (BMD), as elderly patients with hip fractures, are prone to temporary stem migration. Initial subsidence and rotation does not ultimately prevent stem osseointegration, and osseointegrated stems do not develop late mechanical loosening . Bisphosphonates have failed to reduce femoral stem subsidence in various patient populations, including postmenopausal women .…”

Cementing of the hip arthroplasty stem increases load-to-failure force: a cadaveric study

“…2016, Aro et al. 2018), without a correlation to subsidence. Again, a direct comparison like that in this study is yet to be performed.…”

Alendronate enhances osseointegration in a murine implant model

“…[4][5][6][7] TJAs rely on the bone formation of the metaphyseal cancellous bone to achieve osseointegration. [8][9][10] Older patients and those with metabolic bone diseases generally have reduced cancellous bone quality and quantity of putting them at higher risk of aseptic loosening. 5,11,12 Bisphosphonates are the most frequently used agents in the treatment of osteoporosis.…”