A Study to Determine if Carbon Dioxide Lavage During Total Knee Surgery Reduces Intraoperative Embolic Events

• Number of Patients With Emboli in the High Category [ Time Frame: During surgery ] [ Designated as safety issue: Yes ]
• Changes in Neurocognitive Tests Following Surgery [ Time Frame: 2 weeks prior to 1 year following surgery ] [ Designated as safety issue: No ]
• Delirium During Hospital Stay [ Time Frame: First 3 days after surgery ] [ Designated as safety issue: No ]
• Changes in Pulmonary and Renal Function [ Time Frame: Within 3 days after surgery ] [ Designated as safety issue: Yes ]
• Cardiac Injury [ Time Frame: Within 3 days after surgery ] [ Designated as safety issue: Yes ]
• Systemic Inflammatory Response (SIRS) Markers [ Time Frame: Within 72 hours after surgery ] [ Designated as safety issue: No ]
• Biomarkers of Neuronal Damage [ Time Frame: Within 72 hours after surgery ] [ Designated as safety issue: No ]

• The number and size of emboli identified in the right and left heart as measured by TEE [ Time Frame: During surgery ] [ Designated as safety issue: Yes ]
• Changes in neurocognitive tests following surgery [ Time Frame: 2 weeks prior to 1 year following surgery ] [ Designated as safety issue: No ]
• Delirium during hospital stay [ Time Frame: First 3 days after surgery ] [ Designated as safety issue: No ]
• Changes in pulmonary and renal function [ Time Frame: Within 3 days after surgery ] [ Designated as safety issue: Yes ]
• Cardiac injury [ Time Frame: Within 3 days after surgery ] [ Designated as safety issue: Yes ]
• Systemic Inflammatory Response (SIRS) markers [ Time Frame: Within 72 hours after surgery ] [ Designated as safety issue: No ]
• Biomarkers of neuronal damage [ Time Frame: Within 72 hours after surgery ] [ Designated as safety issue: No ]
• Depth of cement penetration under the tibial prosthesis as measured on standard, blinded, routine post-operative radiographs of the knee [ Time Frame: Within the first 30 days after surgery ] [ Designated as safety issue: No ]

The purpose of this study is to determine if the use of a carbon dioxide lavage device (CarboJet) to clean bone surfaces during total knee surgery decreases intraoperative embolic events when compared with standard orthopedic techniques.

Elderly patients undergoing major, orthopedic surgery are at risk of developing postoperative cognitive dysfunction (POCD) or memory impairment following surgery. Transcranial doppler (TCD) monitoring of blood flow to the brain has detected cerebral emboli in 60% of patients following release of the thigh tourniquet during total knee replacement or arthroplasty (TKA). These cerebral embolic events may represent one of the mechanisms responsible for postoperative cognitive problems.

The standard surgical technique for TKA involves cleaning the bone surfaces with pulsed saline lavage prior to cementation and prosthesis insertion. The CarboJet Assisted technique utilizes carbon dioxide lavage to clean and dry the femur canal and bone surfaces prior to cementation and implantation. Because it removes fat globules and marrow particulates from the bone surfaces, it is hypothesized that the use of a carbon dioxide lavage technique in TKA will result in fewer thromboembolic events and increased cement penetration compared with the standard technique using pulsed saline lavage. Cement penetration affects the strength of the bone-cement interface and, therefore, contributes to implant longevity.

• Postoperative Complications
• Memory Disorders

• Device: pulsatile saline lavage
  Prior to cement application, cut bone surfaces are cleaned using pulsatile saline lavage
• Device: carbon dioxide lavage
  Prior to cement application, cut bone surfaces are cleaned using carbon dioxide lavage

• Active Comparator: 1
  Intervention: Device: pulsatile saline lavage
• Active Comparator: 2
  Intervention: Device: carbon dioxide lavage

Inclusion Criteria:

• Adult patients aged 50 years or older who are scheduled for elective TKA with a cemented Smith and Nephew Prosthesis design

Exclusion Criteria:

• Dementia or severe cognitive impairment
• Severe visual or hearing impairments
• Inability to follow directions or comprehend the English language
• Females who are pregnant
• Abnormal distal femur geometry
• Pre-existing hardware or abnormal bony architecture in the proximal tibia