New Technologies - Tony Smith

New Technologies

Cartilage grafting

The re-growth of useful artificial cartilage that can resurface a worn joint has been extensively researched over the last few years. Mr Smith has been involved in the implementation of this technology at the RJAH orthopaedic hospital since his time there as a registrar. He now offers this surgery in the private and NHS sectors, as well as being a member of the UK wide ACTIVE trial. This is a multi-centre trial designed to verify or disprove the effectiveness of cartilage grafting surgery.

ACI

Autologous Chondrocyte Implantation or ACT (T for transplantation) as it is known has been available for many years, the results are very good overall, but certain areas of the knee do better than others. The femoral condyles which are the main weight bearing areas of the knee, show an 80% success rate, still maintained up to 10 years after surgery.		Damaged are Prepared for ACI
The patella-femoral joint give results nearer 50% success. The operation is performed in two stages, the first is a simple daycase arthroscopy to 'harvest' a small amount of healthy cartilage from the knee joint. This cartilage is then 'grown' in the laboratory, which is on site at RJAH. Three to four weeks later, a second operation is performed to place the cartilage cells into the knee. The standard ACI technique involves carefully sewing a patch over the area to be grafted and injecting the cartilage cells underneath to give them a space in which to grow and form new cartilage. The patch can be a small piece of periosteum (the fine tissue covering bone) that is taken from the top of the shin bone at the second stage operation, or more commonly a pre-manufactured collagen membrane. The second stage operation is a larger procedure and will require 3-4 days in hospital. A strict rehabilitation programme will commence in hospital and continue for 12 weeks afterwards.		Collage Patch Trimmed to the correct size Cartilage cells injected under the patch

Rehabilitation protocol

MACI

This procedure is exactly the same as ACI, except for the fact that the newly grown cartilage cells are implanted into the knee using the collagen membrane pre-impregnated with the cells. This makes the technique slightly easier for the surgeon and still appears to give the same results as the standard method of ACI.

After application of the MAC

Cartilage Cell Impregnated Membrane for MACI

Trimming The Membrane to Size

Mosaicplasty and Mega-OAT's

Is a well established technique for repairing damaged joint surfaces in the knee. The surgery is usually performed as an 'open' procedure, i.e. not keyhole. Small plugs of bone are removed from areas of the knee that do not take much load and implanted into the worn area of the joint. Great care is taken to keep the cartilage cap on the bone plug intact so it can be used to 'rebuild' the damaged joint surface. In the last couple of years Mr Smith has had good success with an adaptation of this technique called the 'Mega-OAT's' procedure. This is an option when the damage is extensive, involving not just the joint surface, but underlying bone as well. This is highly specialised surgery and will be discussed with you on an individual basis if it is an option.

Mega-Oats

Posaic plasty

Meniscal Implantation

Mr Smith has had a keen interest in meniscal implantation for many years. This interest stems from the fact that he has looked after a great number of patients who have had their meniscus removed at an early age and gone on to develop severe trouble with the joint in their 20's or 30's.

The principal behind meniscal implantation is to restore near normal function to the joint as much as possible and hopefully prevent future problems. The procedure of meniscal implantation is performed arthroscopically as a 'keyhole' procedure, but is a major operation. As a result, patients need to stay in hospital for 2 to 3 days. During this time they will be able to familiarise themselves with the rehabilitation protocol.

In the early days of meniscal implantation, allograft meniscal tissue harvested from deceased donors was the only source of tissue. Mr Smith has performed a number of these operations, with benefit in all cases. The biggest problem with this procedure is obtaining suitable meniscal tissue, some patients having to wait a year or more for a suitable donor to become available.

Relatively new to the market is a biodegradable synthetic meniscus called the 'Acifit' early results for this implant are encouraging both in the hands of the developing team in Belgium and Mr Smiths experience. The availability of an 'off the shelf' product has removed the need to wait for a suitable donor, but it must be emphasised the long term results of this product are not yet known.

Occasionally the implantation of the new meniscus has to be combined with other procedures such as ACL reconstruction, osteotomy or ACI. The extent of reconstruction required is personalised to each person and this will be discussed with you as required.

Torn Meniscus

Measuring the Meniscal Defect Size

Inserting the Meniscal Implant

Meniscal Implant Sutured in place

Full integration of the meniscal implant several months later

Rehabilitation protocol

Navigation

The use of computers and computer guided navigation has received much coverage in the popular press and medical literature. Mr Smith has evaluated this technology in his practice carefully as it has been introduced. Whilst the theoretical benefits are well documented, no long term results are yet available to justify its routine use yet. For selected, usually complex cases, navigation can be of assistance in ensuring accurate alignment of any implants and he will use it as an additional tool when required.

Custom fit knee replacement

As with computer guided surgery, interest in male/female knee replacement and custom fit knee replacement has been the subject of much debate recently. Presently, the 'jury is out' as to whether this is of benefit or not. Mr Smith has addressed the problem by using the Vanguard total knee replacement system which has design features, including 'half-sizes' that can ensure an accurate size match.

For 2010, Mr Smith has had the MRI scanner at the Spire Yale Hospital calibrated to scan knee joints prior to surgery to allow the manufacture of personalised instruments for every patient as part of the 'Signature' programme. If you think you may be interested in this please discuss it with Mr Smith, who is an evaluating surgeon for this technology in the UK.

Customised signature instrumentation

Femoral Condyle Autologous Chondrocyte Transplantation

Trochlea Autologous Chondrocyte Transplantation