Vitagel Revision Total Knee Arthroplasty

This is a prospective, randomized, blinded clinical trial involving 4 orthopedic surgeons
who perform Revision Total Knee Arthroplasty (RTKA), including Trevor Murray (PI), Viktor
Krebs, Robert Molloy, and Carlos Higuera. A total of eighty subjects scheduled for RTKA, who
meet all inclusion criteria and exhibit none of the exclusion criteria will be invited to
participate in the study. Only subjects who sign the Institutional Review Board-approved
Informed Consent Form will be entered into the Study.

In the forty treatment Subjects, VG will be applied to each surgical site. The forty control
subjects will receive the surgeon's standard of care, without the use of any other
hemostatic agents. The subjects will not be informed of their assignment, and the research
investigator making the determination on blood transfusion requirements for all study
subjects will also be blinded to the subject assigned arm of the study. The research
investigator performing RTKA will remain blinded to the study arm until the randomization
envelope is opened, which will take place during surgery, after hemostasis is achieved using
bovie electrocautery, and prior to closure of the knee capsule.

Assessments will be made per the Time and Events Schedule.

Subjects will be evaluated for intra- and post-operative complications, and all such events,
should they occur, will be recorded during the course of the study. Details describing the
event, cause of event, its treatment and resolution will be documented.

Inclusion Criteria:

- Patients must meet all of the following criteria in order to be considered
appropriate candidates for participation in the study:

1. Is scheduled for RTKA (may be the second stage/reimplantation of a two-stage
revision for infection);

2. Is able and willing to provide voluntary written informed consent for
participation in the study and able to comply with protocol requirements;

3. Is between the ages of 18 and 85 at the time of surgery. Both male and female
will be included;

4. Is physically and mentally willing and able to comply with the clinical and
evaluation follow-up schedule;

Exclusion Criteria:

- The following exclusion criteria address safety and follow-up concerns or
contraindications that could confound the study. If a patient exhibits any one of the
following criteria, the patient is not eligible to participate in this study:

1. Is known to be sensitive to any materials of bovine origin;

2. Is undergoing a bilateral RTKA;

3. Is undergoing a single component revision (i.e. tibial or femoral component
only)

4. Is undergoing a polyethylene revision only

5. Is predonating autologous blood;

6. Have a preoperative platelet count of less than 100,000

7. Have a previous history of venous thromboembolism or deep vein thrombosis;

8. Have a medical condition requiring anticoagulation

9. Currently using Coumadin;

10. Have a history of Heparin induced thrombocytopenia or Lovenox induced
thrombocytopenia;

11. Have a history of rheumatoid arthritis or inflammatory arthritis;

12. Have peripheral vascular disease;

13. Have evidence of bleeding or metabolic-based hemolytic disorder (hemophilia or
anticoagulation use), or hypercoaguable disorder;

14. Have a history of liver disease. Patients with liver dysfunction from cirrhosis
or hepatitis may have impaired production of factors in the clotting cascade
which may make these individuals more prone to bleed, especially with the use of
anticoagulants. For this reason, these patients will also be excluded from the
study if a baseline INR is greater than 1.3 or APTT greater than 32.4;

15. Have a history of failed treatment for abuse of, or are actively abusing,
illegal drugs, solvents, or alcohol;

16. Have a systemic infection or infection at site of surgery;

17. Is a prisoner;

18. Is pregnant or nursing and;

19. Have a condition deemed by physician or medical staff to be non-conducive to
patient's ability to complete the study, or a potential risk to the patient's
health and well-being.

Exclusion Criteria (Intra-operative)

1. Clinical evidence of cancer and/or infection at surgical site

2. Use during the procedure of any other approved or unapproved product for the purpose
of hemostasis