Comparison of ablation technique of drains

Inclusion Criteria:

1. Patients admitted to the orthopedic surgery department for surgery for a total hip arthroplasty
2. Signed inform consent form

Exclusion Criteria:

1. Drain in non-aspirating mode at the time of medical ablation prescription
2. Administration of analgesic III in the 12 hours preceding the inclusion

patient will not know which technique will be used for drain ablation