This is the editor's interpretation of a paper published in the orthopaedic literature in 2012 - our attempt to make relevant medical articles accessible to lay readers. If you want to read the original it is easy to ask your librarian to obtain a reprint for you from any medical library.

Reference:

Decision making in professional athletes with cartilage lesions. Gobbi, A Turgeon D and Karnatzikos, G. In Cartilage Repair: Clinical Guidelines. Publisher DJO, 2012. pp185-208. ISBN 978-0-9561760-0-4.


The authors of this paper discuss the progress in available treatment of knee cartilage injuries in high performance athletes.

They note that in the past attempts at managing functionally limiting cartilage lesions have been palliative, only delaying the onset and progress of arthritis but not preventing it.

The issue, they point out, is that joint cartilage heals poorly because -

  • it has no direct blood supply
  • cartilage contains very few cells
  • the cells it has are highly specialised and unable to change their characteristics to morph into more useful healing cells
  • cartilage has no nerve supply
  • there is also no lymphatic supply

However, in the last 20 years there have been developed a variety of procedures that offer hope to the professional athletes.

The authors explain that the many injuries that are commonplace in a sportsperson result in the repetitive release from bleeding or from the tissues themselves of chemicals into the joints, and many of these chemicals are destructive to the joint cartilage. Furthermore there may be injuries to other structures in the knee such as the ligaments or menisci that affect stability. There may also be bruising of underlying bone. Thus over the years of training and competing, in addition to direct injuries to the joint cartilage, the environment of the knee joint may also be indirectly hostile to the joint cartilage.

The authors progress to discuss the options now available to manage knee injuries in professional athletes -

 

Non-invasive treatment

To minimise cartilage damage after an injury they recommend ice, non-steroidal anti-inflammatories (NSAIDs) and cartilage-protecting drugs such as glucosamine (1,500-2,000 mg / day), chondroitin sulphate (800-1,200 mg / day) and avocado-soy unsaponifiables (300-600 m / day). They point out that these cartilage protecting agents may improve cartilage structure even if symptoms are not relieved.

They also draw attention to the benefit after injury of using partial weight bearing, using a brace to protect the knee from any inappropriate range of movement (ROM) and also stimulating the cartilage with continuous passive motion (CPM). They do not go into details in this section.

 

Injections into the knee

The authors discuss -

  • corticosteroid injections
  • viscosupplementation injections
  • platelet-rich plasma (PRP) injections

Corticosteroid injections

The authors point out that although these may give short term symptomatic relief, they may cause other problems. As corticosteroids impair the normal inflammatory response and actually delay healing, they should not be used immediately after an injury or before a competition.

Viscosupplementation injections

They are talking here about using hyaluronic acid (HA) injected into the knee as an alternative to corticosteroids. Hyaluronic acid is also anti-inflammatory and can protect cartilage without the problems of corticosteroids, but it has its own problems as the knee may flare up temporarily and knock the athlete out of competition for a few days.

Platelet-rich plasma (PRP) injections

PRP is the clear fluid that can be separated out from the red blood cells by spinning a test-tube sample of the patient’s blood in a centrifuge - the platelets are spun into the clear plasma in a high concentration. On injection of this platelet rich plasma into injured muscles, ligaments and tendons the platelets release important chemicals that promote healing and regeneration. PRP can also be injected into the joint cavity itself.

The authors point out that the composition of the PRP differs widely depending on the commercial system used to prepare the plasma. They also say that from January 2011 international and American anti-doping agencies WADA and USADA have lifted their ban on the use of PRP for competing athletes.

 

Pulsed Electromagnetic Fields (PEMFs)

The authors stress the importance of pulsed EMF in protecting cartilage without any negative side effects, limiting inflammation, reducing recovery time and offering long term benefits.

 

Surgical Treatments

The paper briefly discusses current options for surgical treatment of joint cartilage lesions, which include -

 

The authors suggest that -

  • arthroscopic debridement and cartilage abrasion may provide pain relief but do not restore the hyaline cartilage of a normal joint. However they may be appropriate for small cartilage lesions or to remove unstable flaps of cartilage.
  • bone marrow stimulation techniques also tend to lead to the production of the poorer-quality fibrocartilage rather than proper hyaline cartilage, and only a relatively small percentage of athletes manage to return to their pre-injury level of competition
  • OATS and mosaicplasty can restore normal hyaline cartilage but are only applicable to small lesions (10-15 mm).
  • ACI can also restore normal hyaline cartilage and is applicable to larger defects. The procedure has been improved, so that there is not ‘second generation’ and ‘third generation’ ACI techniques labelled thus to distinguish the improved procedures from the less effective original ACI operation. A negative of all these ACI procedures is that they require two surgical procedures – one to harvest the cells for culture in a laboratory and the other to implant the cultured cells. Another negative is that the harvest site may become symptomatic.

They point out that there is as yet NO GOLD STANDARD in terms of management of cartilage lesions in the athlete. The earlier the diagnosis, the shorter the duration of symptoms, the smaller the lesion, the younger the athlete and the better the quality of the rehabilitation programme the greater the chance of a good outcome.

Recently, they say, surgeons are exploring the possibility of a one-stage procedure using mesenchymal stem cells (MSC) which can be harvested from bone marrow [Ed: or blood] rather than harvesting cartilage cells from the knee joint itself. The authors highlight that early results appear to hold promise.

The authors round up the paper by looking at individual sports and the issues of each sport in relation to cartilage injury. This will be an interesting read for injured athletes but is too much to cover in this review.

 

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