Peters 2015.

Trial name or title	The need for supine position advise during sleep in the first eight week after a THA to prevent hip dislocation.
Methods	Stratified block randomised non‐inferiority controlled trial. The study aim is to test the non‐inferiority hypothesis of differences in early hip dislocation between a group of participants who will be restricted to sleep in supine position and a group without restricted sleeping position during the first 8 weeks after a THA following a posterolateral surgical approach.
Participants	Inclusion criteria: people who have/are planned to undergo a primary THA via the posterolateral approach by a high volume orthopaedic surgeon; patients with a ASA‐classification of I or II. Exclusion criteria: blindness; THA within 6 months of the contralateral hip; insufficient knowledge of the Dutch language; Collum fracture; infection of the THA; cognitive dysfunction; wheelchair dependability; hypermobility; alcohol abuse; neurological disorders such as Parkinson's disease and stroke.
Interventions	Experimental: sleep position: no restrictions. Participants do not have any restrictions in sleeping position during the first 8 weeks after a THA following a posterolateral surgical approach. Control: sleep position: supine. Participants will be instructed to sleep in a supine position during the first 8 weeks after a total hip replacement following a posterolateral surgical approach
Outcomes	Primary outcome measure: percentage of early dislocations within the first 8 weeks after THA. Secondary outcome measures: Hip Disability and Osteoarthritis Outcome Score; quality of sleep (VHS), EQ‐5D, visual analogue scale/numerical rating scale hip pain intensity; compliance to anti‐hip dislocation instructions assessed using a diary for patients to report their compliance with the set of anti‐dislocation instructions, among which is the (daily) reporting of their sleeping position in bed at night; sleeping position preferences. Follow‐up: 8 weeks and 6 months postoperative
Starting date	Start date: June 2014 Estimated study completion date: March 2020 Esimated primary competition date: March 2019 (final data collection date for primary outcome measure).
Contact information	Anil Peters (Orthopedisch Centrum Oost Nederland). Email: a.peters@ocon.nl
Notes	Sponsor: Orthopedisch Centrum Oost Nederland ClinicalTrials.gov identifier: NCT02107248. Protocol published: Peters 2015

Abbreviations: THA: total hip arthroplasty.