Canal-to-diaphysis ratio useful for assessing hip fracture risk in elderly
The canal-to-diaphysis ratio (CDR) appears to be a reliable indicator of hip fracture risk in the elderly, with a CDR of 0.60 associated with an increased risk, according to a study presented at the 5th Scientific Meeting of the Asian Federation of Osteoporosis Societies (AFOS 2017) in Kuala Lumpur, Malaysia.
Besides being reliable, evaluating the canal-to-diaphysis ratio is an inexpensive and accessible means of stratifying the risk of hip fracture in the elderly. This is particularly relevant in Asia, where most of the countries are still underdeveloped and have limited resources, said the team of investigators from the Hospital Raja Permaisuri Bainun in Perak, MY.
In the study, the team measured CDR from hip x-rays of 50 patients (mean age 76.22 years; 72 percent female) with trochanteric fractures and 50 controls (mean age 74.32 years; 56 percent female) without fracture. The contralateral, intact side of the hip was used in the patients to avoid errors.
Obtained at a point that was 5-cm distal to the mid-lesser trochanter on an anteroposterior view, CDR measurements revealed a significant difference between the fracture and control groups (0.13 vs 0.14 SD, respectively; p=0.001). [AFOS 2017, abstract BPA 01]
At a CDR index of 0.60, the risk of a hip fracture was fourfold greater in the fracture group than in the control group. This suggests that individuals with CDR >0.60 are at greater risk of trochanteric fracture, the investigators said.
In addition, a Pearson correlation coefficient of 0.843 showed an acceptable correlation between CDR and age, indicating an increase in CDR with advancing age.
The present study demonstrates a significant direct relationship between CDR and hip fracture risk, the investigators said. “Patients with CDR >0.60 should be given extra attention in treating osteoporosis as they are at higher risk of fracture.”
The investigators are optimistic that CDR can facilitate wider screening of elderly individuals to prevent hip fracture and improve the quality of life in this population, as CDR is a simple method of calculation that can be taught and understood by all levels of medical personnel.
Nevertheless, larger scale studies are needed to further establish the relationship between CDR and hip fracture in osteoporotic patients as confirmed by dual-energy x-ray absorptiometry evaluation, they added.