Predictors of total hip replacement in community based older adults: a cohort study

V Mezhov,L.L Laslett,H Ahedi,C.L Blizzard,R.M Aspden,J.S Gregory,F.R Saunders,S Graves,M Lorimer,I.P Munogoda,G Cai,F.M Cicuttini,G Jones

doi:10.1016/j.joca.2019.02.112

Abstract

Purpose: Multiple predictors of hip replacement have been described, but whether they are independent of the current gold standard predictors (pain and radiographic hip OA) is unclear. Therefore, we aimed to describe predictors of total hip replacement (THR) independent of hip pain and radiographic measures of hip OA in a community dwelling sample of older adults. Methods: At baseline, participants (n=682) had assessment of radiographic osteoarthritis (OA) and cam morphology (from pelvic radiographs), shape mode scores (from dual emission X-ray absorptiometry (DXA)) and femoral neck bone mineral density (BMD) (also from DXA). After 2.6 and 5 years, participants reported hip pain using WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index),and had hip structural changes assessed using magnetic resonance imaging (MRI). Incidence of THR was assessed over 13 years. Risk of THR was analysed using mixed-effect Poisson regression, and modelled using Cox proportional hazards regression. Results: Incidence of THR for OA over 13 years was 5.9% (n=40). As expected, WOMAC hip pain and hip radiographic OA both predicted risk of THR (Figure 1). Additionally, both shape mode 2 score (decreasing acetabular coverage) (IRR 1.53 per SD; 95% CI 1.09-2.14), and shape mode 4 scores (non-spherical femoral head) (IRR 0.61/SD; 95% CI 0.42-0.88) predicted risk of THR. Cam impingement (alpha angle>60°) increased risk of THR (IRR 2.65; 95% CI 1.34-2.32) (Figure 2), as did BMD of the neck of femur (IRR 1.73/SD, 95% CI 1.28-2.32). Bone marrow lesions increased THR risk (IRR 4.97; 95% CI 0.97 to 25.44) but this was not statistically significant, possibly due the smaller sub-cohort (n=185, p=0.055). Age, BMI and sex, and steps per day were not independent risk factors (see Table). Conclusions: In addition to hip pain and radiographic hip OA, measures of hip shape, CAM morphology and BMD independently predict THR risk. These factors can be used to develop models for improving prediction of THR.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Highlights

IntroductionMultiple predictors of hip replacement have been described, but whether they are independent of the current gold standard predictors (pain and radiographic hip OA) is unclear
Multiple predictors of hip replacement have been described, but whether they are independent of the current gold standard predictors is unclear
Histological analysis of ACAN mice knee joints demonstrated a regional lack of proteoglycan staining and decreased chondrocyte numbers when compared to the WT control (Figure 1)

Summary

Introduction

Multiple predictors of hip replacement have been described, but whether they are independent of the current gold standard predictors (pain and radiographic hip OA) is unclear. WOMAC hip pain and hip radiographic OA both predicted risk of THR (Figure 1). Both shape mode 2 score (decreasing acetabular coverage) (IRR 1.53 per SD; 95% CI 1.09-2.14), and shape mode 4 scores (non-spherical femoral head) (IRR 0.61/SD; 95% CI 0.42-0.88) predicted risk of THR. Cam impingement (alpha angle>60) increased risk of THR (IRR 2.65; 95% CI 1.34-2.32) (Figure 2), as did BMD of the neck of femur (IRR 1.73/SD, 95% CI 1.28-2.32). Conclusions: In addition to hip pain and radiographic hip OA, measures of hip shape, CAM morphology and BMD independently predict THR risk. These factors can be used to develop models for improving prediction of THR

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