Relative factors and follow up research of asymptomatic osteonecrosis of the femoral head

Abstract

Objective: To evaluate the progress and influence factors of asymptomatic osteonecrosis of the femoral head(ONFH). Methods: MRI was performed on the contralateral hips of 174 patients with unilateral symptomatic ONFH who admitted at Department of Orthopaedics, the Second Affiliated Hospital of Xi'an Jiaotong University from January 2012 to December 2018. Eighty-three of 174 patients with unilateral ONFH were found suffering from contralateral ONFH(47.7%), of which 77 patients were followed up.There were 28 males and 49 females with age of 48.6 years (range: 21-73 years). The pathogenesis, ARCO classfication, areas and position of osteonecrosis were collected.Independent sample t test, χ(2) test, Fisher exact test, multivariate Logistic regression were used to analyze the potential influence factors. Results: Patients were followed up for 36.7 months. During the following up period, ARCO classification of 28 patients (36.4%) progressed.The progress of asymptomatic ONFH was not related to the gender, age and original ARCO classification, but related to the pathogenesis, position and area of osteonecrosis (all P<0.05). Conclusion: The progress of asymptomatic osteonecrosis is related to the pathogenesis, position and area of osteonecrosis,but most of asymptomatic ONFH will not progress.