Mepivacaine vs. Bupivacaine Spinal for TKA

Study Overview
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Brief Summary
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This study will enroll patients 18-75 years of age who are undergoing elective primary total knee replacement. The patients will be randomized to receive one of two spinal blocks: 1) mepivacaine or 2) bupivacaine. The primary goal is to determine which group arrives at recovery of motor function first. Ultimately, this study will explore if mepivacaine leads to earlier return of motor function and ultimately earlier movement and discharge times following total knee replacement.

Official Title
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Mepivacaine vs. Bupivacaine Spinal: Effect on Return of Motor Function, Time to Ambulation, and Length of Stay in Total Knee Arthroplasty

Conditions
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Total Knee Replacement

Intervention / Treatment
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* Other: Mepivacaine Spinal
* Other: Bupivacaine Spinal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 18-75 years of age Undergoing elective primary total knee arthroplasty Exclusion Criteria: Inability to ambulate or impaired motor function in lower extremities prior to surgery Contraindication to spinal anesthetic Taking over 30mg oxycodone per day (or calculated MME equivalent) Subjects that are unable or choose not to give informed consent Known preoperative substance abuse Pregnant women Allergy to all opioids

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Mepivacaine Spinal<br>Mepivacaine (60 mg: 3ml of 2%) or will be injected into the intrathecal space. | Other: Mepivacaine Spinal<br>* spinal block using 60mg of mepivacaine<br>|
| Active Comparator: Bupivacaine Spinal<br>Isobaric bupivacaine (10mg: 2ml or 0.5%) will be injected into the intrathecal space. | Other: Bupivacaine Spinal<br>* spinal block using 10mg of bupivacaine<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time until return of motor function following spinal placement | This will be defined as full strength with both 1) foot plantar and dorsiflexion and 2) hip flexion in the operative extremity. | From anesthesia stop time until 7 days post-op | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ambulation | Time to first ambulation and distance at first ambulation | from anesthesia stop time until 7 days post-op | 
| Length of Stay | based on anesthesia end time to time discharge order written | Time from anesthesia end time to when discharge order is written, up to 30 days post-op | 
| Side Effects | Side effects such as Urinary retention, dizziness, symptomatic hypotension, transient neurologic symptoms | 0-48 hours post spinal placement | 
| Pain Scores | Visual Analog Pain Score 0-100 pain scores at rest, and with movement. A lower pain score means a better outcome. | Pacu to 48 hours post-spinal placement |