New sur­gi­cal me­thod to enable a life like be­fore knee arthrosis

Doc­tors at the Evan­ge­li­cal Hos­pi­tal in Vi­enna have de­ve­lo­ped an in­no­va­tive me­thod that ta­kes in­di­vi­dual ana­tomy into account.

In the course of a hu­man life, the car­ti­lage in the knee joint is sub­ject to heavy stress: it con­stantly cushions mo­ve­ments and is ex­po­sed to fric­tion from the bo­nes. It is the­r­e­fore not sur­pri­sing that ar­thro­sis, espe­ci­ally knee ar­thro­sis, is one of the most com­mon chro­nic di­se­a­ses in the population. 

If the joint is com­ple­tely de­s­troyed, a joint re­pla­ce­ment be­co­mes ne­ces­sary. Ho­we­ver, pa­ti­ent re­ports show that af­ter such an ope­ra­tion, they of­ten find their ar­ti­fi­cial knee to be un­na­tu­ral or suf­fer from pain. 

That could now ch­ange. At the Evan­ge­li­cal Hos­pi­tal in Vi­enna, a new mi­ni­mally in­va­sive sur­gi­cal me­thod has been used for se­ve­ral months for the im­plan­ta­tion of ar­ti­fi­cial knee joints. The goal: pa­ti­ents should then be able to walk and run again just as they did be­fore knee arthrosis. 

How does it work? The motto is “back to the ori­gin,” says Pri­mar Tho­mas Müll­ner, Head of the De­part­ments of Or­tho­pe­dics and Trau­ma­to­logy. Tog­e­ther with Dr. Ma­xi­mi­lian Kas­pa­rek, spe­cia­list in or­tho­pe­dics and trau­ma­to­logy, he has de­ve­lo­ped the new sur­gi­cal me­thod, which is now ex­pec­ted to enable ma­jor ad­van­ces in the field of ar­ti­fi­cial knee joint replacement. 

Es­sen­ti­ally, the me­thod is ba­sed on in­ter­na­tio­nal re­se­arch re­sults show­ing that every knee is dif­fe­rent and a com­ple­tely straight leg is not the na­tu­ral norm. Ho­we­ver, this in­di­vi­dual ana­tomy has not been ta­ken into ac­count in most ca­ses to date. “We are now re­con­s­truc­ting the in­di­vi­dual bio­me­cha­nics and ana­tomy of our pa­ti­ents for the first time, as it was be­fore the knee ar­thro­sis – in other words, we are go­ing back to the ori­gin to enable our pa­ti­ents to live a life like be­fore the ar­thro­sis,” says Müllner. 

3‑D na­vi­ga­tion

This is made pos­si­ble by the use of state-of-the-art tech­no­logy: “By me­ans of th­ree-di­men­sio­nal na­vi­ga­tion, the ne­ces­sary bone cuts for the ar­ti­fi­cial knee joint are made with mil­li­me­ter pre­cis­ion. The in­di­vi­dual band ten­sion and ob­li­quity of the na­tu­ral joint line are ta­ken into ac­count,” the doc­tors describe.

The si­gni­fi­cant ad­van­tage of this me­thod com­pared to other com­pa­ra­ble me­thods is that con­ven­tio­nal knee pro­sthe­sis im­plants can be used. In ad­di­tion, ad­di­tio­nal in­ter­ven­ti­ons on the soft tis­sues, which were of­ten ne­ces­sary in the past to bring the knee into an un­na­tu­ral tar­get area of a straight leg, are no lon­ger ne­ces­sary with the new technology. 

Müll­ner and Kas­pa­rek are very sa­tis­fied with the preli­mi­nary re­sults: “Since the in­tro­duc­tion of this new sur­gi­cal tech­ni­que, we have been able to ob­serve that our pa­ti­ents have si­gni­fi­cantly less pain im­me­dia­tely af­ter the ope­ra­tion and quickly show very good mo­bi­lity,” says Kas­pa­rek. “We are now see­ing the first short-term re­sults and many pa­ti­ents re­port that their ar­ti­fi­cial knee joint feels like it did 20 or 30 ye­ars ago, when they had no pain,” re­ports Müllner.