Please assess the completion status of the following clinical trial:

Trial Title: Methadone vs Magnesium in Spinal Fusion

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: SUPPORTIVE_CARE
- Time Perspective: None
- Masking: SINGLE
- Phase: PHASE2
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion Criteria:~* Patients older than 12, and younger than 19 years of age undergoing posterior spinal fusion for idiopathic scoliosis~* American Society of Anesthesiologist (ASA) physical status I or II~* Parents/Guardian willing and able to authorize informed consent~* Patients willing and able to authorize assent~Exclusion Criteria:~* Patients presenting with neuromuscular scoliosis~* Patients deemed at increased risk of adverse reactions due to the presence of pre-existing severe organ system dysfunction, including debilitating lung disease, severe obstructive sleep apnea, severe congenital or acquired heart disease, and/or severe renal impairment~* Patients who are both being currently treated for a psychological disorder and have a history of hospitalization for said disorder

- Gender: ALL
- Minimum Age: 12 Years
- Maximum Age: 19 Years
- Healthy Volunteers: f

Study Arms:
- Remifentanil (Type: ACTIVE_COMPARATOR): This arm will receive remifentanil alone as is the current practice.
- Remifentanil plus methadone (Type: EXPERIMENTAL): This arm will receive the current analgesic remifentanil plus and adjunct dose of methadone hydrochloride.
- Remifentanil plus magnesium (Type: EXPERIMENTAL): This arm will receive the current analgesic remifentanil plus an adjunct dose of magnesium sulfate.

Based on this trial design, predict the completion outcome and termination type (if applicable).