Question

It appears that Grandma will need a total joint replacement. There are many different types of hip designs and fixation methods. Describe to Grandma the advantages and disadvantages of utilizing PMMA as a bone cement and how it integrates into the bone

Answer 1

Advantages of PMMA as a bone cement.

             * It is highly compatible with human tissue so it can used as a bone cement.

             * It help to attach implants and remodeling of lost bones in the body.

             * It can used as a glue when conducting arthroplasty (surgical repair of joints).

             * PMMA fill the spaces between the prosthesis and restict vigorous movement

               of bone.

Disadvantages of PMMA

              * MMA (Methyl methacrylate) present in the PMMA may act as an irritant and shows

                carcinogenic properties.

              * When heating bone cement up to 180.5 fahrenheit at the time of setting it may cause

                 thermal necrosis of adjucent tissues.

              * It may cause embolism in the circulatory system when used for anchorage of femoral

                 joints by increasing intramedullary pressure during material inserted into the cleared

                 femoral canal.

PMMA integration into the bone.

             * PMMA when used as a bone cement it consist of 2 components.

             * The two components are PMMA or initiator and a liquid (stabilizer).

             * This two component are mixed which result in radical polymerization (a process

                 in which formation of polymer by addition of free radical building blocks) of the

                 MMA monomer when the initiator is mixed with the accelerator.

             * During this process viscosity of bone cement change from liquid state into semi solid

                state and after application it harden as a solid material and properly integrate into the

                bone.