Spire Cheshire Hospital is pleased to introduce another minimally invasive orthopaedic knee procedure: meniscal transplant surgery performed by consultant knee surgeon Mr Fahad Attar.
Patients who have undergone CMI implantation often feel able to return to their usual activities sooner than they had expected
CMI (Collagen based Biosynthetic Scaffold)
The Collagen Meniscus Implant (CMI®) is a biological and completely absorbable implant. It is attached to fill the gap in the meniscus (shock absorbency disc) through a keyhole procedure in the knee. This is to address the damaged and lost meniscal tissue and makes use of the body's own healing ability.
The absorbable implant initially serves as a scaffold and guide for the migration of the body's own cells and is completely absorbed afterwards. More than 10 years of published clinical experience has proven that this is an established procedure for loss of meniscus tissue treatment. A meniscal defect filled with new tissue potentially reduces the risk of arthritis and produces outstanding clinical results, thus improving patients' quality of life and physical resilience.
CMI is intended for use in patients with an irreparable meniscus tear or loss of meniscus tissue.
When a meniscus tear can’t be reattached by suturing, it is considered an 'irreparable meniscus tear'. Often the defective meniscal parts must be removed. If parts of the meniscus are removed without some form of substitution, the upper and lower surfaces of the knee joint rub directly on each other and the cartilage (joint lining) layer is gradually worn away.
Studies have revealed that even partial removal of the meniscal tissue can increase cartilage forces and lead to degenerative changes of the articular surfaces.[3-6] These can result in considerable pain and stiffness. Due to the degenerative nature of osteoarthritis, patients may eventually need an artificial knee joint.
The Collagen Meniscus Implant was developed to prevent or delay these long-term consequences of osteoarthritis following partial meniscectomy.
Once it is determined a patient is a good candidate for the CMI procedure, the steps are fairly simple. The suitability is dependent on how much meniscal tissue is left and how much wear and damage is already present in the knee.
A brief overview of what the patient can expect is outlined below:
- The surgeon will perform a routine arthroscopy, key hole surgical procedure in the knee, to confirm the meniscus injury and the appropriateness of the CMI procedure.
- The surgeon will prepare the meniscus by removing any remaining damaged tissue.
- The meniscus defect will be measured, and the scaffold will be trimmed to fit.
- The scaffold will be placed into the knee joint through the arthroscopic portal.
- The device will be sutured in place.
- The surgeon will close the small openings in the knee that were used to access the joint space.
1) Irreparable meniscus tear
2) Resected meniscus damage / prepared implant site
3) Implanted scaffold
4) New meniscus-like tissue
Rehabilitation and physiotherapy following surgery
Patients who have undergone the meniscal scaffold implantation often feel able to return to their usual activities sooner than they had expected. Therefore, it is vital that the patient remind themselves, that although the operated knee may not be causing discomfort, the actual healing process has only just begun.
Download the full rehabilitation protocol.
Published results with the collagen based biosynthetic scaffold have shown improved pain and function levels at 10 years follow up  and it potentially protects their knee from further damage and reduces the onset of arthritis.
Meniscal replacement using an allograft
When patients have had an extensive meniscal resection in the past, due to a large tear, they may not have much meniscal tissue left and in this group of patients it is difficult to suture a biosynthetic graft. It may be more suitable for this group of patients to have their whole meniscus replaced using an allograft.
Tissue surgically transplanted from one person to another is called allograft. Bone, tendons and cartilage, skin, heart valves and veins are common types of tissues that are used for transplant to help patients in many different types of surgeries.
One of the most common allograft procedure in the UK is ACL reconstruction where non-bone tendons are routinely used to replace damaged ligaments in the knee.
Every surgical procedure involves risk from multiple factors. The question is how to reduce that risk to an absolute minimum.
The safety of any tissue is contingent upon three stages – donor screening, laboratory testing and tissue preparation validated to address potential disease transmission.
Screening, testing and sterilising for patient safety
A complete medical/social history must be performed for every donor including cause of death, lifestyle risk assessment and family interviews.
Beyond donor screening, extensive tests are performed. These results are subject to stringent acceptance criteria in order to release the donor tissue.
In addition to lab testing on the donor’s blood, lab testing is used throughout the process (where appropriate) to screen for potential contamination and to provide confirmation of tissue suitability for transplant.
All soft tissue allografts used for this meniscal replacement procedure are sterilised through a patented process called BioCleanse. The BioCleanse system sterilises tissue using a complex combination of mechanical and chemical processes, working in conjunction with each other.
Overall, published results show that 70-75% of patients have improved pain and function levels following the allograft meniscal transplant procedure and it potentially protects their knee from further damage and reduces the onset of arthritis .
The rehabilitation and physiotherapy following the meniscal allograft replacement is similar as above to the absorbable biosynthetic scaffold replacement.
To make an appointment with Mr F Attar please call 01925 215087 or complete the enquiry form on the right hand side of this page.
- NICE interventional procedure guidance. guidance.nice.org.uk/ipg430, July 2012
- Outcome after partial medial meniscus substitution with the Collagen Meniscal Implant at a minimum of 10 years Follow up, Juan Carlos Monllau, Pablo Eduardo Gelber, Ferran Abat, Xavier pelfort, Rosa, Pedro Hinarejos, Marc Tey. Arthroscopy, Vol. 27, Issue 7, Pages 933-943, July 2011
- Fairbank TJ. Knee joint changes after meniscectomy. J Bone Joint Surg Br. 1948;30B:664–670.
- Cole BJ, Carter TR, Rodeo SA. Allograft meniscal transplantation:background, techniques, and results. Instr Course Lect. 2003;52:383–396.
- Chatain F, Adeleine P, Chambat P, et al. A comparative study of medial versus lateral arthroscopic partial meniscectomy on stable knees: 10-year minimum follow-up. Arthroscopy. 2003;19:842–849.
- Englund M, Roos EM, Lohmander LS. Impact of type of meniscal tear on radiographic and symptomatic knee osteoarthritis: a sixteen year follow up of meniscectomy with matched controls. Arthritis Rheum. 2003;48:2178–2187.
- Meniscal Allografts: Indications and Outcomes, Rene Verdonk, Karl F. Almqvist, Wouter Huysse, Peter C. Verdonk, Sports Med Arthrosc Rev., Vol.15, No.3, September 2007