The study is being conducted to evaluate the safety, and efficacy of HRS-2129 for Postoperative analgesia in orthopaedics. To explore the reasonable dosage of HRS-2129 for Postoperative analgesia in orthopaedics.

Inclusion Criteria:

1. Able and willing to provide a written informed consent
2. Subjects requiring elective orthopedic surgery
3. Conform to the ASA Physical Status Classification

Exclusion Criteria:

1. Subjects with a history of severe allergies
2. Subjects with nervous system disease
3. Subjects with a history of mental illness
4. Subjects with abnormal liver and renal function
5. Subjects with poorly controlled hypertensive or hypotensive
6. QTc：>450ms（male），>470ms（female）
7. Subjects who screened positive for substance abuse
8. History of cardiac dysrhythmias requiring anti-arrhythmia treatment(s)
9. The investigators determined that other conditions were inappropriate for participation in this clinical trial