Epidemiological Study Based on China Osteonecrosis of the Femoral Head Database

Abstract

Objective: The aim of the present study was to reveal the case characteristics of osteonecrosis of the femoral head (ONFH) in Mainland China.

Methods: This cross-sectional epidemiological study derived data for ONFH patients from July 2016 to December 2018 from the China Osteonecrosis of the Femoral Head Database (CONFHD). The derived data included gender, age, body mass index (BMI), height, occupation, region, and etiology of femoral head necrosis. A descriptive analysis was performed to summarize the epidemiological characteristics of the case data in the CONFHD.

Results: A total of 1844 ONFH patients (2945 hips) were included in this study, comprising 1302 men and 542 women. The age of patients ranged from 18 to 95 years, with a median of 50 years, and the male to female ratio was 2.4. Male patients are younger than female patients (48.26 ± 12.56 years old and 55.56 ± 14.94 years old, respectively). Among the 1844 patients (2945 hips), there were 528 (17.92%) hips at ARCO stage I, 941 (31.99%) hips at ARCO stage II, 873 (29.63%) hips at ARCO stage III, and 603 (20.46%) hips at ARCO stage IV. In the subclassification of ARCO stages I and II, the majority of cases were type C; type A comprised the majority in the subclassification of ARCO stage III. According to the Kellgren-Lawrence classification system, among the 603 ARCO stage IV hips, there were 178 (29.52%) grade 1 hips, 201 (33.34%) grade 2 hips, 176 (29.18%) grade 3 hips, and 48 (7.96%) grade 4 hips. Most were from three provinces: Henan (27.3%), Shanxi (13.9%), and Shandong (11.9%). Regarding BMI, 982 patients (53.25%) were overweight or obese. Among all patients, the largest proportion of patients engaged in level IV manual work. Of all the patients, there were 495 (26.84%) with steroid-induced ONFH, 685 (37.15%) were alcoholics, and 290 (15.73%) had traumatic ONFH. The 495 patients with steroid-induced ONFH included 278 men (56.16%) and 217 women (43.84 %), had a complete history of hormone use. Among the primary diseases, there were 195 cases (39.39%) of immune system diseases, followed by dermatological diseases, respiratory diseases, nephropathy, and other diseases. There were a total of 685 patients with alcoholic ONFH, 589 of these patients (85.99%) were men. A total of 188 (27.45%) patients had drunk alcohol for 6-10 years (comprising the highest proportion), and 280 patients (40.88%) consumed 3001-3500 mL of alcohol each week (the highest proportion).

Conclusion: Osteonecrosis of the femoral head most commonly occurs after the age of 40. Male patients have an earlier onset than female patients, and the number of male patients is approximately twice that of female patients. The BMI of patients was mainly in the overweight and obese range, and half of these patients engaged in level IV manual work. From the imaging findings, the numbers of hips at ARCO stages II and III were greatest, and the number at stage I was relatively small. Among all the causes of disease, alcohol, steroid use and trauma were the three most common reasons for ONFH.

Keywords: Case registration system; Epidemiology; Etiology; Osteonecrosis of the femoral head.

Fig 1

Age distribution of patients with osteonecrosis of the femoral head (ONFH) in China Osteonecrosis of the Femoral Head Database. The age of the patients was mainly between 41 and 60 years. This indicates that ONFH mainly affects young to middle‐aged people.

Fig 2

BMI composition of patients with osteonecrosis of the femoral head (ONFH) in the China Osteonecrosis of the Femoral Head Database. More than half of the patients are overweight and obese.

Fig 3

A, Schematic diagram of the regional distribution of patients in CONFHD. The provinces and cities with the largest proportions were: Henan Province, 503 (27.3%); Shanxi Province, 257 (13.9%); Shandong Province, 220 (11.9%); Guangxi Zhuang Autonomous Region, 128 (6.9%); and Hebei Province, 116 (6.3%). B, Bar chart of the regional distribution of patients in CONFHD. The top three regions for the number of patients are: Central China, 524 (28.4%); East China, 520 (28.2%); and Northwest China, 313 (17%).

Fig 4

Bar chart of labor intensity distribution of patients engaged in the China Osteonecrosis of the Femoral Head Database. The largest number of patients are engaged in level IV manual work. This implies that heavy physical labor may also be one of the risk factors for osteonecrosis of the femoral head.

Fig 5

A, Etiological distribution of patients by gender in the China Osteonecrosis of the Femoral Head Database (CONFHD). (Osteonecrosis of the femoral head [ONFH] occurs mainly in men, and the main cause of the disease is alcoholism in men and hormones in women). B, Etiological composition of patients in CONFHD. (The results show that alcoholism and steroid‐induced ONFH are still the main causes of femoral head necrosis in mainland China)