Treatment with acetylsalicylic acid prevents short to mid-term radiographic progression of nontraumatic osteonecrosis of the femoral head: a pilot study

Abstract

Background: Nontraumatic osteonecrosis of the femoral head (ONFH) is a progressive disease in young adults producing substantial morbidity and frequently resulting in total hip arthroplasty. Although hip-preserving surgical procedures represent the current mainstay of treatment for early disease, medical therapies targeting specific pathways in the ONFH pathogenesis could help prevent disease progression while producing less morbidity. Acetylsalicylic acid (ASA) is a promising alternative to other therapies for ONFH owing to its anti-inflammatory and antithrombotic mechanisms of action and its relatively benign side effect profile.

Methods: We followed a prospective cohort of 10 patients (12 hips) with precollapse ONFH who were given ASA to prevent disease progression. Their outcomes were compared with those of a historic control group taken from the literature.

Results: Progression occurred in 1 of 12 (8%) patients taking ASA compared with 30 of 45 (66.6%) controls (p = 0.002) at a mean follow-up of 3.7 years. Patients taking ASA also tended to exhibit decreased femoral head involvement at the end of therapy.

Conclusion: This hypothesis-generating study leads us to believe that ASA may be a simple and effective treatment option for delaying disease progression in patients with early-stage ONFH.

Figures

Fig. 1

(A) Patients taking acetylsalicylic acid (ASA) and historical controls with any presenting Ficat & Arlet stage osteonecrosis of the femoral head (ONFH) after more than 2 years of follow-up. The ASA group exhibited a significantly lower percentage of cases with radiographic progression of ONFH. (B) Patients taking ASA and historical controls initially presenting with Ficat & Arlet stage 0–2 ONFH after more than 2 years of follow-up. Even when controlling for presenting ONFH stage, the ASA group exhibited a significantly lower percentage of cases with radiographic progression of ONFH. *p < 0.05.

Fig. 2

Percent osteonecrosis of the femoral head (ONFH) involvement of the femoral head in patients prior to and following an average of 2 years of acetylsalicylic acid (ASA) administration.

Fig. 3

(A–B) Section of T1-weighted coronal MRI and plain radiograph of a 61-year-old patient presenting with Steinberg stage II osteonecrosis of the femoral head (ONFH) in the left hip and 90% femoral head involvement (circle in panel A). (C–D) Follow-up section of T1-weighted coronal MRI and plain radiograph of the same patient after treatment with oral acetylsalicylic acid (ASA) for < 12 months. The ONFH involvement of the femoral head increased, with evidence of subchondral collapse (circle in panel C) and progression to Steinberg stage IV ONFH.