to be very patient and also extremely cooperative. They usually need to be on crutches for four to six weeks (sometimes longer). Sometimes a brace is needed. This all depends on the size and/or location of the joint surface defect that is being repaired or regenerated. The patients are encouraged to spend approximately 6–8 hours a day on a CPM (continuous passive motion) machine that helps with optimal re-growth of joint surface. The procedure can be painless for some patients to the extent that the patients avoid these critically important steps and expose the knee to physical activity before the joint fully heals. However, with other patients the procedure can be very painful for weeks even months. Pain medication may be required to manage pain levels in those patients. Steadman cites the significance of a patient's natural joint alignment in addition to disciplined rehabilitation in recovery from the procedure. References External links MedlinePlus Medical Encyclopedia Sports medicine Orthopedic surgical procedures