The number of hip prosthesis implantations is rapidly increasing all over the world, but sooner or later the prosthesis loosen up. During the loosening the bone weakens, as a result the risk of the surgery exponentially increases. There are two kind of hip prostheses: cement restricted hip prostheses and cement free hip prostheses.
Our institute developed bio-compatible bone plug for cement restricted hip prosthesis.
Bio-compatible bone plugs keep the cement (which holds the hip prosthesis) from getting into the bone cavity and to totally fill up the gaps between the bone and the prosthesis, because this ensures the proper fastening of the prosthesis. After it has fulfilled its function, it would be absorbed by the body fluids.
Tests were performedin order to determine the mechanical, physiological, viscoelastical, temperaturerelated stability and the solubility of the material. The mechanical stabilitywas determined with a press. The solubility of the substance was also tested invitro. Animal tests were preformed on pot-bellied pigs.
Today the plugs most used in Hungary are made from the femoral head of the patients. In the rest of the European Union, the market uses plastic and gelatine plugs.
The plugs made from the femoral head of the patients infiltrate into the bone and not being temporary. It causes difficulties and increases the risk of irreversible injuries through prosthesis revision, because the plugs are needed to carve before the revision prosthesis is implanted. The plastic plugs have the disadvantage of not being temporary and it behaves as strange matter in the bone. Through the revision of the prosthesis the plug has to be removed by dangerous and technically difficult procedures.
The gelatine plug is absorbed in the bone but these are not enough mechanic stable and the prosthesis can slip through the operation and/or while the cement is binding.
Bio-compatible bone plugs simplify the procedure needed to be done in case of a prosthesis revision, lower the risk, which is caused by the removal of permanent plugs. It shortens the time of the procedure by 25%, which means this technology makes the time of procedure shorter by one hour. The patient spends one hour less in sleep, and the doctors and the assistants would save 25% of their capacity. Further advantage is that it saves 25% of the blood used for a surgery.