Total Knee Artroplasty (TKA) is becoming more and more popular, even in the younger active age group. In this age group however the results are not that reproducible as in the older age group. People are more limited in their activities of daily living and complain more about pain, stifness and swelling. At the end and in general the younger age group is less satisfied than the older patients.

The last decade minimal invasive solutions with modified instruments, Gender Knees, the use of navigation in TKA, ligament-based techniques, fast rehab protocols etc have all been introduced to make the results of TKA better. These are all elements that indeed can make the patient better. However the most important on the short term and the long term is the use of the correct implant size and the correct implantation of the prosthetic components.

Since January 2011 we routinely use patient specific instruments in TKA patients under 60y that are very active or in older less active patients with important anatomic malformations. A CT-based system that scans the hip-knee-ankle is used. The data are sent to an engineer and a digital proposal is sent back to the surgeon that can approve the different measurements performed. Once approved the patient specific cutting blocks are sent to the surgeon. In our department we use the Advance Medial Pivot Knee System as our standard knee system since its introduction thirteen years ago. Since then more than 2000 implantations have been performed. This experience has made it possible to critically evaluate the patient specific cutting block technique.

The first results are very satisfying. During surgery less ligamentous releases had to be performed, there was in all cases an optimal patellofemoral tracking without any release, there was less blood loss and surgery time was decreased. At all times during surgery we were very satisfied how we could verify all surgical steps and this is in our opinion very important. During the first postoperative days the patients experienced less pain (routine VAS recorded), there was a faster return to full ROM and patients asked to go home earlier.

After two months patients are routinely followed up and they undergo a clinical and radiographic exam. All prosthetic components were implanted the way we had planned it. The overall axes were restored and up till now no complications were noticed. All patients experienced a fast recovery with full ROM at 2 months, no complaints about pain or swelling and very interestingly no residual intra-articular swelling which is often seen in these active and younger patient group. Patients are also asked to fill in a patient-based outcome measurements (KOOS) questionnaire.

In our opinion it is a very easy and promising system for the experienced surgeon. Younger and less experienced surgeons however should be warned that they cannot blindly trust the system. We surgeons have to control what the engineer has proposed before and during surgery.