Sharp Dissection Versus Monopolar Electrocautery in Primary Total Knee Arthroplasty Performed Under Tourniquet

Study Overview
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Brief Summary
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This study compares the use of sharp dissection with diathermy for the approach to a total knee replacement. Half of the patients will be randomly assigned each intervention.

Detailed Description
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The approach to the knee to carry out a total knee replacement (TKR) can either be carried out using a scalpel, sharp dissection, or using an electric current to divide tissue, monopoly electrocautery. Reducing blood loss is important. Blood loss can result in anaemia, which has a number of effects including shortness of breath, chest pain and lethargy. Blood loss into a newly replaced knee can also result in pain and stiffness in the joint. Total knee replacements are routinely carried out with a tourniquet inflated, which reduces the blood flow into to leg during the operation. Diathermy is applied to areas of bleeding to stop them from doing so during operations. With the tourniquet inflated, some areas that would bleed when this was deflated may not be noticed and continue to bleed. Using diathermy for the approach would be expected to reduce this bleeding compared to using a scalpel.

Official Title
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Sharp Dissection Versus Monopolar Electrocautery in Primary Total Knee Arthroplasty Performed Under Tourniquet: a Randomized Double Blind Controlled Trial

Conditions
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Osteo Arthritis Knee, Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Procedure: Sharp dissection with scalpel plus electrocautery to vessels
* Procedure: Electrocautery for all dissection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Primary knee osteoarthritis requiring TKA (total knee arthroplasty) Planned for cruciate retaining prosthesis without patella resurfacing Patient is able to give informed consent Patient resides locally and will be available for follow up Exclusion Criteria: Cardiac pacemaker Inflammatory arthropathy Tourniquet contraindicated Thrombophilia/haemoglobinopathy Spinal anaesthetic not possible
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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: A total of 70 participants will be randomized in a 1:1 ratio to either Treatment Group 1 (sharp dissection with scalpel plus electrocautery to obvious vessels) or Treatment Group 2 (electrocautery for all dissection) using the sealed opaque envelope randomization technique.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Treatment Group 1<br>Sharp dissection with scalpel plus electrocautery to vessels | Procedure: Sharp dissection with scalpel plus electrocautery to vessels<br>* A scalpel will be used for dissection for TKA implantation. Bleeding vessels will be managed as encountered with electrocautery. Electrocautery will not be used for dissection.<br>|
| Active Comparator: Treatment Group 2<br>Electrocautery for all dissection | Procedure: Electrocautery for all dissection<br>* Skin incision will be made with a scalpel, but all other dissection will be performed with electrocautery.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24hr Calculated blood loss | Will be done using the Nadler and Gross formulae | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Haemoglobin drop | Haemoglobin drop from day 1 full blood count test | 1 day | 
| Transfusion requirement | If the patient requires blood transfusion or not | 2 days | 
| VAS (Visual Analogue Scale) pain score 24 and 48 hrs | Patient's pain score at 24 and 48 hours post-operatively | 2 days | 
| Range of motion 48hrs and 6 weeks | Knee range of motion in degrees at 48 hours and 6 weeks post-operatively | 6 weeks | 
| Length of hospital stay | Length of inpatient stay in hospital | 2 weeks | 
| Improvement in Oxford knee score at 12 months | Oxford Knee Score, designed to assess function and pain after total knee replacement. Scored from 0 (severe knee symptoms with functional limitation) to 60 (absence of pain and limitations) | 12 months | 
| Adverse events | Any complications encountered | 12 months |