Ian McDermott presents at the OPN Knee Conference in Leeds on his use of Vivostat PRF to improve outcomes after Knee Replacement surgery. 1st November 2019

This blog is a summary of the presentation that was given by Mr Ian McDermott at the OPN Knee Conference in Leeds on 1st November 2019.



Knee replacement surgery is a major surgical procedure, with not-insignificant risks and requiring extensive post-operative rehab afterwards. In our practice we have adopted several techniques, all of which in synergy can contribute to:

  • decreased post-operative pain,
  • decreased post-operative knee swelling,
  • easier and faster early post-operative recovery and
  • improved patient experiences and better patient outcomes.

Just some of the factors that contribute to this in knee replacement surgery are:

  • The use of custom-made knee prostheses from Conformis, that require less bone removal and that are less invasive (intramedullary rods are not required, because the system uses custom-made 3D-printed patient-specific cutting blocks). CLICK HERE for further info.
  • The use of a limb tourniquet is minimised, and a tourniquet is used only relatively briefly part-way through the operation, specifically just when cementing the prosthesis to the bone.
  • A high-volume pericapsular Marcaine (long-acting local anaesthetic) injection is giving into the tissues around the knee at the end of the operation.
  • An ultrasound-guided subsartorial femoral nerve block injection is given by the anaesthetist, to numb the sensory nerves around the knee but without numbing the motor fibres.
  • All of our patients are advised to use a Game Ready machine post-operatively, for regular icing and compression of the joint, which reduces pain and swelling.
  • It is also vitally important that patients start regular, intensive, high quality rehab treatments with a senior experienced physiotherapist after knee replacement surgery, starting as soon as possible after the surgery and continuing for as many months post-operatively as the patient might need.

Vivostat PRF

Vivostat PRF is a system for preparing platelet-rich fibrin (PRF) from a patient’s own blood. PRF is effectively a bioactive bioabsorbable biological ‘glue’. The fibrin is the sticky part of a normal blood clot, and the platelets from the blood are concentrated x 8, and these release growth factors over the first 7 days or so after application.

The Vivostat Towers for preparation and delivery of the PRF

Blood is taken from the patient’s arm in the anaesthetic room and prepared in the fully-automated Vivostat system.

Within 1/2 hour, the Vivostat PRF is ready for use in theatre, with a special spray pen delivery system for spraying the tissues inside the knee before skin closure.

I first used Vivostat PRF as a glue / sealant (instead of Tisseel, which is a glue that is produced from pooled human plasma (i.e. from multiple donors), and which doesn’t have any platelets in it) for securing Chondrotissue cartilage grafts in place in the knee, for articular cartilage grafting in the knee. (CLICK HERE for further information on articular cartilage grafting.) However, in 2014 I was made aware of a study by Fornaciai et al from The Campo di Marte Hospital in Lucca, Italy. In this study the authors investigated the use of Vivostat PRF to reduce bleeding in knee replacement surgery. The authors compared 48 knee replacement with vs 48 without the use of Vivostat PRF, and they found that the use of Vivostat PRF reduced the average amount of post-op blood loss, reduced the % change of their patients needing blood transfusions post-operatively, and it reduced the amount of blood units that needed to be transfused.

In 2014 I therefore adopted the use of Vivostat PRF as an adjunct to the knee replacement surgery that I was doing. If one can reduce the bleeding from knee replacement surgery, then the hope is that one can also:

  • reduce the need for blood transfusions,
  • reduce post-operative knee swelling and pain,
  • improve post-operative recovery and rehab, and
  • improve overall patient outcomes.


We conducted a retrospective audit of 106 patients who had undergone knee replacement surgery under my care, comparing 59 patients where Vivostat PRF had been used to an historical control group of 47 patients where Vivostat PRF had not been used.

The outcomes measures we examined were:

  • Hb drop from pre-operatively to post-operatively,
  • blood transfusion rates,
  • length of hospital stay,
  • time taken post-operatively until the patient could manage stairs,
  • post-op pain scores and
  • knee range of motion (ROM) at 3 days post-op and at 3 months post-op.


A total of 4 patients (3.8%) needed post-operative blood transfusions: 2 in the Vivostat group vs 2 in the control group.

The intra-operative Hb drop showed a statistically significant difference, with a drop of 27.5g/Dl in the Vivostat PRF group vs a larger drop of 31.9 in the control group (p=0.019).

There were no statistically significant differences in the pain scores / analgesia used; however, the early rehab performance was improved in the Vivostat PRF group, with a quicker return to stairs post-operatively (p=0.04).

ROM at day-3 post-op was 5o better in the Vivostat PRF group vs the control group (p=0.0018), and at 3 months post-op was 7.8o better (p=0.004).

What was not controlled for in this study was the type of knee prosthesis that was used, but nowadays our standard practice is to use custom-made prosthesis almost exclusively, for almost all of our patients.


This retrospective historic control cohort audit suggests that there are some positive benefits from the use of Vivostat PRF as a haemostat in knee replacement surgery, with less of a drop post-operatively in Hb, with a shorter time until the patient is able to manage stairs, and with a better range of motion at 3 days and at 3 months post-op.

I have adopted the use of Vivostat PRF for my knee replacement procedures as one part of a concerted cohort of factors that together all help achieve better outcomes for our knee replacement patients:


Find out more:

CLICK HERE to read more about Vivostat PRF



Mr Ian McDermott


5 November 2019


Biological glue