Bone Cement


                      Bone cement 

Component - Powder - Pre-polymerized PMMA

                                      Barium Sulphate (opacifier)

                    Liquid-      Mono Methyl-metha-acrylate (MMA Monomer )

                                       N-dimethyl-p-toludine, which acts as an accelerator (accelerator )

                                        Hydroquinone , which acts as an inhibitor

                                       Colour e.g. Chlorophyll


What factors influence its properties ?

            Porosity -vacuum mixing improve fatigue strength.

            Antibiotics 

            

Methods of applications .

    Digital 

    syringe application

    vacuum mixing and delivery

    pressurisation

    viscosity

    use of stem centralizer and cement restrictor

Bone bed preparation 

    Bone reaming ,

    Brushing

    Pulse Lavage 

  

Cementing Techniques 

        First Generation tecnique

                hand mixing of cement in bowels

                canal irrigated and suctioned before digital application of cement 

                cancellous bone left in situ 

        Second Generation technique 

                all cancellous bone removed

                distal cement restrictor applied

                irrigation , packing and drying of femoral canal done then cement application using cement                     gun in a retrograde fashion

       Third Generation Technique

               cement preparation using vacuum-centrifugation technique

                canal irrigation with pulsatile lavage and packed with adrenaline soaked swabs

                cement insertion in retrograde fashion, then cement pressurized.

                then used proximal and distal cement centralizers. 

                

    Risks 

                Hypotensive episodes

                Cardiac arrests

                Arrythmia

                Hypoxaemia 

                Delayed sciatic nerve entrapment due to cement extrusion

                adhesion and stricture of ileum during cement polymerization

                promotes local inflammation and results in peri-prosthetic osteolysis (activated macrophages express cytokines inculding IL-1,6,TNF -alpha )

                

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