Trial Outcomes & Findings for Patient Controlled Epidural Analgesia Versus Local Infiltration Analgesia Following Knee Arthroplasty (NCT NCT02478372)

NCT ID: NCT02478372

Last Updated: 2015-11-10

Results Overview

% of patients meeting predetermined discharge criteria at 96 Hours post-surgery. The discharge criteria were: self dependent (dress, personal care); in and out of bedd independently; up and down stairs; walk with crutches/stick; 80 degrees knee flexion; able to straight leg raise operated limb.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 242 participants
• Primary outcome timeframe: 96 hours
• Results posted on: 2015-11-10

Participant Flow

Participant milestones

Measure	Patient Controlled Epidural (PCEA) A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Overall Study STARTED	121	121
Overall Study Recieved Allocation Intervention	109	113
Overall Study Reviewed at Six Weeks	108	113
Overall Study Reviewed at One Year	108	107
Overall Study COMPLETED	108	107
Overall Study NOT COMPLETED	13	14

Reasons for withdrawal

Measure	Patient Controlled Epidural (PCEA) A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Overall Study Protocol Violation	12	8
Overall Study Lost to Follow-up	1	4
Overall Study Death	0	2

Baseline Characteristics

Patient Controlled Epidural Analgesia Versus Local Infiltration Analgesia Following Knee Arthroplasty

Baseline characteristics by cohort

Measure	Patient Controlled Epidural (PCEA) n=121 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=121 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.	Total n=242 Participants Total of all reporting groups
Age, Continuous	66 years STANDARD_DEVIATION 10 • n=5 Participants	68 years STANDARD_DEVIATION 11 • n=7 Participants	67 years STANDARD_DEVIATION 7.6 • n=5 Participants
Sex: Female, Male Female	66 Participants n=5 Participants	71 Participants n=7 Participants	137 Participants n=5 Participants
Sex: Female, Male Male	55 Participants n=5 Participants	50 Participants n=7 Participants	105 Participants n=5 Participants
Region of Enrollment United Kingdom	121 participants n=5 Participants	121 participants n=7 Participants	242 participants n=5 Participants
Body Mass Index	31 kilogrammes per meter squared STANDARD_DEVIATION 8 • n=5 Participants	31 kilogrammes per meter squared STANDARD_DEVIATION 8 • n=7 Participants	31 kilogrammes per meter squared STANDARD_DEVIATION 8 • n=5 Participants

PRIMARY outcome

Timeframe: 96 hours

Population: Patients included following randomisation

% of patients meeting predetermined discharge criteria at 96 Hours post-surgery.

The discharge criteria were: self dependent (dress, personal care); in and out of bedd independently; up and down stairs; walk with crutches/stick; 80 degrees knee flexion; able to straight leg raise operated limb.

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Proportion of Patients Discharged From Rehabilitation by Day Four	77 percentage of patients	82 percentage of patients

SECONDARY outcome

Timeframe: Average number of days spent in hospital follwoing surgery, an expected average of 5 days

Participants will be followed for the duration of hospital stay, an expected average of 5 days

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Average Post-operative Length of Stay	4 days Interval 2.0 to 20.0	4 days Interval 2.0 to 12.0

SECONDARY outcome

Timeframe: 24hours, 48 hours and 72 hours post-surgery

Summary 24 hour Verbal rated numerical pain scores were gathered each day. Scale range 0-10 where 0 is no pain and 10 is worst imaginable pain

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Verbal Rating Score (VRS) Pain Scores Theatre Day( asked at 24 hrs)	3 units on a scale Standard Deviation 4	3 units on a scale Standard Deviation 4
Verbal Rating Score (VRS) Pain Scores Post-operative day one( asked at 48hrs)	3 units on a scale Standard Deviation 3	4 units on a scale Standard Deviation 3
Verbal Rating Score (VRS) Pain Scores Post-operative day two(asked 72 hrs)	3 units on a scale Standard Deviation 2	4 units on a scale Standard Deviation 3

SECONDARY outcome

Timeframe: 72 hours post-surgery

% of patients requiring catheterisation for urinary retention post-surgery

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Post-operative Urinary Catheterisation Rates	9.2 percentage of patients catheterised	4.4 percentage of patients catheterised

SECONDARY outcome

Timeframe: 24hours, 48 hours and 72 hours post-surgery

percentage of patients reporting either symptoms of nausea or vomiting over the first 72 hours following surgery. Scale 0-2 wherein 0=no nausea and vomiting, 1=nausea and 2= nausea and vomiting

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Post-operative Nausea and Vomiting Scores	16 percentage of patients reporting PONV	14 percentage of patients reporting PONV

SECONDARY outcome

Timeframe: theatre day, day 1 post-surgery, day two post-surgery

Proportion of patients per day to ambulate for the first time with the physiotherapist > 3 Metres

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Day of Ambulation Theatre Day	35 percentage of patients	51 percentage of patients
Day of Ambulation Post-operative day one	65 percentage of patients	49 percentage of patients
Day of Ambulation Post-operative day two	4 percentage of patients	0 percentage of patients

SECONDARY outcome

Timeframe: On day of discharge from rehabilitation in-patient care (average 96 hours post surgery)

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Maximal Flexion Angle of the Operative Knee at Discharge From Rehabilitation	80 angle of flexion (degree) Interval 60.0 to 100.0	80 angle of flexion (degree) Interval 65.0 to 105.0

SECONDARY outcome

Timeframe: one week prior to surgery, 6 weeks post-surgery , one year post-surgery

Units measured on old Oxford Score (12-60) from a 12 point questionnaire. Where in 60 is poor and lower scores are better patient reported outcome scores

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Patient Reported Outcome Measure - Oxford Knee Score Pre-operative Oxford Score	43 units on a scale Interval 23.0 to 55.0	43 units on a scale Interval 20.0 to 57.0
Patient Reported Outcome Measure - Oxford Knee Score Six week follow up score	28 units on a scale Interval 13.0 to 53.0	26 units on a scale Interval 13.0 to 48.0
Patient Reported Outcome Measure - Oxford Knee Score One year Follow up score	19 units on a scale Interval 12.0 to 46.0	19 units on a scale Interval 12.0 to 54.0

SECONDARY outcome

Timeframe: 30 days and one year post-surgery

The composite number of adverse events reported per group at 30 days and then one year post surgery

Outcome measures

Measure	Patient Controlled Epidural (PCEA) n=109 Participants A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 Participants Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Total Number of Reported Participants With Complications and/or Adverse Events Reported complications at 30 days	0 participants	2 participants
Total Number of Reported Participants With Complications and/or Adverse Events Reported complications at one year	2 participants	4 participants

Adverse Events

Patient Controlled Epidural (PCEA)

Serious events: 2 serious events

Other events: 0 other events

Deaths: 0 deaths

Local Infiltration Analgesia (LIA)

Serious events: 6 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Measure	Patient Controlled Epidural (PCEA) n=109 participants at risk A lumbar epidural was sited following establishment of the spinal blockade. Following the completion of the operation, patients received 4ml of 0.25% levobupivacaine prior to leaving the operating room. Thereafter they were connected to a PCEA pump (McKinley 545) with no background infusion. Patients could self-medicate with a bolus 2ml of 0.125% bupivacaine via the PCEA system with a lockout time of 15 minutes until the following morning (post-operative day one). Nurse-administered rescue top-ups of 4ml of 0.25% levobupivacaine were available for insufficient analgesia. The epidural catheter was removed on the morning of post-operative day two (POD2).	Local Infiltration Analgesia (LIA) n=113 participants at risk Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine. 50ml injected following bone preparation prior to implant cementation perpendicular to the posterior femur through the posterior joint capsule in 10ml aliquots. 30ml proximal to the suprapatellar pouch down to the femur.100ml spread into subcutaneous tissues including; collateral and cruciate ligaments, fatty and connective tissue on the anterior aspect of the incision. A 16 gauge epidural catheter inserted via a medial portal, 20ml was injected via the catheter following closure of wound. Post-operatively, patients received boluses of 40ml ropivacaine 0.2% via the catheter using a mechanical McKinley 595 pump 4 hours after leaving theatre, at 22:00 and 08:00 on post-operative day one. Local Infiltration Analgesia (LIA): Subcutaneous infiltration during surgery using 200ml of 0.2% plain ropivacaine.
Skin and subcutaneous tissue disorders wound Infection at 30 days	0.00% 0/109 • 30 days post-surgery and one year following surgery	0.88% 1/113 • Number of events 1 • 30 days post-surgery and one year following surgery
Gastrointestinal disorders GI Bleed at 30 days	0.00% 0/109 • 30 days post-surgery and one year following surgery	0.88% 1/113 • Number of events 1 • 30 days post-surgery and one year following surgery
Cardiac disorders Acute Myocardial Infarction at one year	0.92% 1/109 • Number of events 1 • 30 days post-surgery and one year following surgery	0.00% 0/113 • 30 days post-surgery and one year following surgery
Skin and subcutaneous tissue disorders Wound Infection at one year	0.92% 1/109 • Number of events 1 • 30 days post-surgery and one year following surgery	0.88% 1/113 • Number of events 1 • 30 days post-surgery and one year following surgery
Renal and urinary disorders Renal Failure at one year	0.00% 0/109 • 30 days post-surgery and one year following surgery	0.88% 1/113 • Number of events 1 • 30 days post-surgery and one year following surgery
General disorders Death at one year	0.00% 0/109 • 30 days post-surgery and one year following surgery	1.8% 2/113 • Number of events 2 • 30 days post-surgery and one year following surgery

Other adverse events

Adverse event data not reported

Additional Information

David McDonald

Golden Jubilee National Hospital

Phone: 07914861078

Email: david.mcdonald@nhs.net

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place