This study is designed to determine if one anaesthetic modality, either motor sparing nerve block or peri-articular local infiltration anaesthesia with infusion, is superior in providing postoperative analgesia following total knee joint arthroplasty and if the efficacy of analgesia affects TKA outcomes. These outcomes include pain and function for a period of up to 3 months, narcotic consumption, and specific non-pain complications, including cardiac, respiratory, central nervous system, thromboembolism, infection, nausea and vomiting and urinary retention. Economic outcomes will also be examined, including length of hospital stay, direct health care costs and patient satisfaction.

Brief Title

Motor Sparing Block vs. Peri-Articular Catheters

Official Title

Outcomes After Total Knee Joint Arthroplasty: A Comparative Study Using 3 Different Analgesic Techniques

Brief Summary

This study is designed to determine if one anaesthetic modality, either motor sparing nerve<br /> block or peri-articular local infiltration anaesthesia with infusion, is superior in<br /> providing postoperative analgesia following total knee joint arthroplasty and if the efficacy<br /> of analgesia affects TKA outcomes. These outcomes include pain and function for a period of<br /> up to 3 months, narcotic consumption, and specific non-pain complications, including cardiac,<br /> respiratory, central nervous system, thromboembolism, infection, nausea and vomiting and<br /> urinary retention.<br /><br /> Economic outcomes will also be examined, including length of hospital stay, direct health<br /> care costs and patient satisfaction.

Detailed Description

Seventy patients of either sex with ASA physical status of 1-3, aged greater than 30 years
scheduled for elective primary unilateral total knee arthroplasty will be the randomized to
one of 2 groups. The patients will be identified by the surgeons and seen in the pre-admit
clinic to obtain informed consent, and collect health and joint related data using SF-12,
Knee Society Scores, and WOMAC surveys. The randomization will occur in the pre-admit clinic
with a closed envelope system. This is not a blinded study for logistical reasons.

Group 1: Control- Motor Sparing Nerve Block Continuous Motor sparing knee block (using 60mL
of 0.5% Ropivacaine with 10 mg Morphine, 30 mg Ketorolac and 150 mcg of epinephrine as the
initial bolus) initiated in the preoperative period in the block room by anesthesia as per
the standard practice( 25mL for posterior knee infiltration, 5mL for LFCN, 25mL for adductor
canal under the fasica lata, 5ML for intermediate cutaneous nerve of thigh) and continued
until discharge. CADD infusion pump will deliver Ropivacaine 0.2% at a basal infusion rate of
8 mL/Hr with no patient controlled boluses.

Group 2: Intervention- Local Infiltration + Infusion Anesthetic Wound infiltration will first
be completed per standard practice using 110mL of ropivacaine 300mg, ketorolc 30mg ,morphine
10mg for infiltration. After, three peri-articular catheters (inserted into the suprapatellar
pouch, anterior subcutaneous cutaneous tissue, posterior to the femur) will be inserted at
the end of the case followed by periarticular infusion with CADD infusion pump delivering
Ropivacaine 0.2% at a basal infusion rate of 8 mL/Hr with no patient controlled boluses

All patients will receive sedation with fentanyl and midazolam titrated to effect during the
initiation of spinals and MSNB blocks. All patients will receive intravenous sedation with an
infusion of a mixture of propofol and ketamine titrated to effect during surgery. Patients
will be discharged home following removal of the anaesthetic catheters and fulfilling
criteria for discharge

All patients will receive standard multimodal analgesia pre- and post-operatively.

Pain scores, nausea/sedation, narcotic consumption, and any post-operative complications will
be assessed and documented 6 hours post-op on the day of surgery. After this, pain scores
will be documented twice daily till the end of pian study period (post-discharge day 4 and
once more at 2 weeks post-op) and will be recored when at rest and with mobility (two VAS
scores each assessment) . Nausea and sedation will be documented at time of assessment from
the patient or nursing charts as well as the patient pain diary.

The discharge criteria is as follows

1. The patient should be able to take care of personal care, get in and out of bed, into
and up from a chair, on and off a toilet and to walk with proper walking aids 70 m
without time limit; ability to do five steps.

2. Free of medical or surgical complications including urinary catheterization or need for
blood transfusion

3. Acceptable pain relief (NRS = 5/10) without any need for intravenous analgesics.

4. No nausea/ vomiting; generalized weakness or dizziness.

5. Knee flexion of 90 degreeed is optional but preferred.

The patients will be assessed at 6 hours of arrival to PACU and at 9 AM and 2pm on POD 1. If
the patients were not discharged on POD 1 , the readiness for discharge will be at 9 AM on
postoperative day 2 subsequently. WOMAC scores, KSS scores and SF-12 will be collected at the
Pre-admit clinic and will be repeated at 6 weeks and three months postoperatively. Block
performance characteristics prospectively collected will include procedural time, success,
number of attempts and complications such as persistent paresthesia and intravascular
injection. Inpatient assessment by the research team as well as a pain diary for
documentation following discharge will be used to collect data including numeric pain score
on movement and rest at various time intervals (twice daily), the predominant site of pain,
frequency of rescue analgesic consumption, total analgesic consumption, symptoms of sedation
and nausea for up to 4 days post-discharge. Time to first physiotherapy session and their
progress/ability to perform rehabilitation exercises daily will be documented. Regardless of
the group the patient is randomized to, their anesthetic device (MSNB or LIA infusion) will
be discontinued and removed in hospital prior to discharge. Time to discharge readiness and
actual duration of hospital stay will be documented.

Total patient involvement time is 3 months (from surgery to 3 month follow-up appointment).

In hospital, adverse events will be retrieved from patient charts and nursing/physician
documentation. Post discharge adverse events will be collected by the patient diary and at
their 2 weeks, 6 week and 3 month post-operative follow-up. These will include occurrence of
myocardial events, DVT, Pulmonary emboli, delirium, pneumonia, paralytic ileus,
gastrointestinal bleed, new onset renal dysfunction and wound infection.

Delayed or post- discharge adverse events and duration of narcotic therapy will be collected
in the out-patient clinic at 2 weeks and at 6 weeks and 3 months after surgery at their
follow-up appointment.

Wound and prosthetic infections and the presence of chronic post-surgical pain will be
recorded from the surgical follow up notes.

Primary hypothesis (null):

The post-operative inpatient stay and discharge rates following TKJA are comparable between
motor sparing knee blocks and peri-articular wound catheters.

Secondary hypotheses (null):

1. Pain scores and analgesic consumption with motor sparing block or by peri-articular
wound catheters are comparable.

2. Adverse events and complication rates are comparable between the two groups.

Outcome Measures

Outcome measures are the tests that investigators perform to prove whether or not a treatment being tested in a clinical trial is having any effect.

Inclusion Criteria:

Adult patients ASA physical status 1-3, Ability to give informed consent, No
contraindications to regional techniques, Ability to perform study related tests, Scheduled
for primary unilateral total knee arthroplasty

Exclusion Criteria:

Revision of arthroplasty, Allergy to local anesthetics and multimodal analgesic drugs,
Contraindications to spinal anesthesia, Inability to perform study related procedures,
Inability to give informed consent, Wheel chair bound, Pregnancy, Chronic renal failure,
BMI >45