General Principles

3.7.1 Nutrition and Joint Circulation Exercises

In order to maintain nutrition of the articular cartilage the synovial fluid needs to circulate around the knee, remembering that cells source their nutrition from the joint fluid, not the bone marrow base. This is aided by joint circulation exercises, stimulating synovial fluid production and nutrition of articular cartilage. Movement exercises need to be undertaken in low load conditions and should be repetitive. Use of the continuous passive motion machine is felt to improve nourishment of transplanted cells. Exercises for this phase include use of the CPM (continuous Passive Motion machine), heel slides, cycling and rowing activities without resistance.

3.7.2 Protection and Injury Prevention Post-Surgery

Braces are often used to protect the knee joint from overload during the first 6 – 8 weeks after surgery. Types of braces include a post-operative protection brace or a functional unloader brace and the principle is to avoid loading the joint surface in an unsafe position.

The patello femoral joint is particularly sensitive to shear load over the range of motion and therefore a brace is used to prevent bending of the knee in the first phase. Functional off loader braces may be used for medial or lateral compartment repair in order to reduce load during the maturation phase.

Prevention of re-injury is also important – the injury to the joint surface occurred due to a particular reason and avoiding certain activities may prolong the durability of the repair. This includes analysis of identified risk factors, including poor posture control, over training, and muscle control, while remembering that the principle is to avoid excessive shear stress on the new surface.