Custom-made LINK Endo-Model still completely intact after 26 years in situ

Case Report: directLINK 2/2018

A 51-year-old former tumor patient with a customized LINK Endo-Model­­- M Knee Prosthesis, right, in situ for 26 years, contacted LINK on account of knee instability. An additional problem was that the surgeon who implanted the prosthesis had retired, and the hospital where the operation was performed in 1991 no longer existed in its original form. Specific data about the prosthesis was no longer available. Following a proximal tibia fracture caused by a fall, the patient feared that she might lose her leg.

All the technical drawings of custom-made LINK prostheses are held in the LINK archive, including this LINK Endo-Model- M Knee Prosthesis implanted in 1991. Spare parts for a sleeve revision are available from stock. Together with the original surgeon, Prof. Dr. med. Martin Salzer, LINK organized the revision procedure for the patient at the Gersthof Orthopedic Hospital in Vienna, Austria, where it was performed by the medical director, Prof. Dr. med. Peter Ritschl.

There, the essentially pain-free patient presented with a flexion deficit in the right knee. The working diagnosis was »a sleeve failure«. Shortly after the patient had presented at the Gersthof Orthopedic Hospital, she suffered a fall, resulting in a proximal tibial fracture. For this reason, the planned sleeve revision procedure was brought forward and performed in January 2017.

Intraoperatively, the sleeve was found to be intact and, like the associated inlay, displayed scarcely any signs of wear even after 26 years in situ. Therefore, the diagnosed flexion deficit in the right knee, which the patient stated she had experienced for many years, was most likely not due to a mechanical problem. 

During the further course of the intervention, the old, intact sleeve was removed lege artis, and replaced with a new sleeve. The tibial bone defects incurred in the fall was restored with bone from a bone bank. The patellar tendon was fixated with a screw and stabilized in the proximal tibia by means of two bone anchors.

When the customized prosthesis was implanted in 1991, the tibia was additionally fixated with two screws, whose heads were not countersunk into the tibial plate. This meant that the new inlay supplied by LINK could not be implanted initially. As the two screws were no longer performing any function in terms of tibial stability, they were removed. This produced a smooth tibial surface for implanting the inlay. The in situ Endo-Model - M Knee Prosthesis was otherwise stable. 

»I am now back to my old self, and fully mobile again following the operation and healing of my fractured shinbone«, the patient Manuela Voack reported. »I’m delighted that LINK was able to help me, and that everything worked out perfectly!«