Microfracture / Abrasion Arthroplasty

If the damage in the joint is severe, a more radical procedure may be undertaken to stimulate some healing. This healing process does take a long time and it could be 9-12 weeks before everyday activities become completely comfortable.

At operation the poor quality cartilage surrounding the lesion will be cleared thus leaving a `crater’ for want of a better description. The bottom of the crater is either abraded or drilled to produce bleeding of the underlying bone – this bleeding will form the basis for the development of new fibrocartilage. Although not as good as the original articular cartilage it is better than bare bone and hopefully will produce a more even joint surface.

During the early weeks of recovery the crater area is very fragile, the blood will have formed a clot but this can easily break up. If the operation has been performed on a weight bearing part of the joint you will have to use crutches for a period of 6 – 8 weeks to allow adequate development of the new cartilage. If the operation is on the back of the kneecap or the adjacent bone then you will be able to walk normally but will have to avoid putting any pressure through a bent knee (i.e. going up & down stairs, walking on steep slopes, squatting etc.) for the same period of time. Thereafter activity should be gradually increased but it is advisable to avoid too much stress if optimum healing is to take place. The physiotherapist will guide you and recommend exercises and activities which will promote rather than inhibit healing.

The damaged area will go on developing for months after surgery so it may be prudent to reconsider certain sporting activities. Your physiotherapist or surgeon will discuss the future prognosis regarding activity levels with you.


These techniques are designed to affect a degenerating joint surface by stimulating regeneration of fibrocartilage.

  • It is vital that the affected area is not over-loaded whilst this recovery takes place (anything from six weeks to six months).
  • The tibio-femoral joint should be protected by a period of minimal weight-bearing (as dictated by the surgeon), followed by a period of gradually increasing partial weight bearing.
  • The patello-femoral joint should avoid loading (ie. flexion beyond 20’ in a weight bearing situation) by squatting, stairs or open kinetic chain activities with weights.
  • The joints respond well to movement, such as static cycling, as there are low joint compression forces. Patients may be advised to have a CPM machine at home for 4 -6 weeks
  • Occasionally braces may be used to help the patient adhere to the necessary protocol.
  • Patients should be advised that rehabilitation can be a lengthy process as intra-articular healing takes time.