This randomized, single surgeon, placebo controlled, double blind study will be conducted in order to investigate whether or not peri-operative high doses of intravenous glucocorticoids improve short-term functional outcome after direct anterior total hip arthroplasty. So far, it has been proven that high dose glucocorticoids reduce immediate post-operative pain and nausea, but no data exists on functional outcome during the first 6 weeks. Our hypothesis is that patients in the intervention group will follow a so-called "get ahead, stay ahead" principle and that glucocorticoids can be considered an important tool (adjuvant treatment) in the enhanced recovery pathway after THA with significant socio-economic implications.

Patients listed for a direct anterior total hip arthroplasty by a single surgeon will be recruited for this study and allocated to one of two groups:

1. intervention group: 25 grams of iv dexamethasone at induction followed by 10 mg of iv dexamethasone 12 hours later
2. control group: 5 grams of iv dexamethasone at induction followed by placebo 12 hours later Both patients and surgeons will be blinded. Primary outcome measure will be number of steps during the first 6 weeks as measured by a pedometer. Secondary outcome measures will be side effects, complications, Patient Reported Outcome Measures, pain, nausea, stiffness, achievement of clinical milestones and use of analgesia/anti-emetics. This data will be collected using a tailor made application for a smartphone or tablet and data collecting will start one week before surgery until 6 weeks after surgery.

Based on a power analysis both groups will consist of 35 patients each.

Inclusion Criteria:

• All patients undergoing unilateral uncemented THA for primary OA or AVN of the hip under general anesthesia (GA)
• Aged 18 years and above (including women of child bearing age)
• Able to provide informed consent

Exclusion Criteria:

• Younger than 18 years
• Known alcohol or drug abuse
• Known allergy for glucocorticoids
• Administration of any glucocorticoids in the last three months
• Usage of strong analgesia (such as lyrica or oxycodone) as regular medication
• Usage of medication with anticipated interactions with glucocorticoids
• Known gastric ulcer
• Insulin dependent diabetes mellitus
• Severe heart disease (NYHA > 2)
• Liver or renal failure
• Systemic rheumatoid diseases
• Insufficient understanding of the Dutch language
• Unable to provide informed consent
• Pre-operative use of walking aids
• Gross anatomical deformities
• Significant intra-operative complications such as periprosthetic fracture

An anesthetist or study nurse not involved in further care of the patient nor in the study will prepare the medication to administered based on the allocated group. The first syringe with either 5 or 25 mg of Aacidexam will be administered during induction. The second syringe will go with the patient to the ward and will be administered 12 hours after the surgery by the (blinded) ward nurse. The patient will not be made aware of what has been administered.