Indications and expectations for the MACI procedure
MACI is indicated for treatment of areas of damage to the articular surface where more simple treatments such as arthroscopic debridement (smoothing of the worn surface) have not helped and when there are significant symptoms limiting activities of daily living and work. The usual symptoms are pain on activity and mechanical symptoms of crunching, grating and catching of the roughened damaged surfaces. Technically, the area of damage treated is usually over 3 – 4 cm2 as other procedures can be effective in smaller areas of damage.
The expectation of the procedure is to re-grow a good enough joint surface to last many years to allow good enough function for light sport activities and work. This means that it is not really indicated for patients who just have pain on peak activities such as playing football or other impact sports. It is better in those situations to cut back on activities rather than undergo the procedure of MACI cartilage repair. The results are simply not good enough to predictably enable return to such sports.
MACI is therefore aimed at younger healthy adults who have suffered damage to the knee joint surfaces and who have significant symptoms. We say ‘young’ because the technology depends on the cells being able to re-grow a new articulating surface, so there is unfortunately a biological age limit on the technique – usually age 50 – 55.