Bone cements consist of two primary components: a powder consisting of copolymers based on the substance polymethyl methacrylate (PMMA), and a liquid monomer, methylmethacrylate (MMA). These two components are mixed at an approximate ratio of 2:1 to form a polymethyl methacrylate cement
Fun with the Gun! – Workshop
on Cementing technique
Dr Vaibhav Bagaria
MBBS, MS, FCPS
Origyn Health Care, Nagpur & Delhi
CARE Hospital, Nagpur
Bone bed preparation - Clean bone bed
Mixing & Delivery
Pressurization - Good cement filling
Safe working environment
Expecting unexpected & dealing with it!
Cement – Other uses
Cement - Basics
Two primary component – PMMA
powder and a liquid monomer – MMA.
Mixed in ratio of 2 :1 to form PMMA
To make it radioopaque: zirconium
dioxide (ZrO2) or barium sulphate
Process of Polymerization
Four Phases: Mixing, Pickup, working and
Important Factors – temperature, humidity,
type of mixing and type of cement.
Manual handling of the cement and body
temperature will reduce the final setting time.
Variation in setting time over the cement’s
shelf life can be minimized by storing the
cement under the recommended conditions.
Low viscosity: Long-lasting liquid, or mixing
phase, which makes for a short working
phase. Requires strict adherence to
application times but gives time for filling
High viscosity: Short mixing phase, loose
their stickiness quickly. Longer working
phase, giving the surgeon more time for
Bone Bed Preparation
Effective micro-interlock between the
bone - cement is essential.
Use of Pressure Pulse lavage and
brush have shown to reduce the
incidence of aseptic loosening.
Curettes, knives can be used but not as
Bone Bed Preparation
Key – To preserve the cancellous bone.
Aim – Good microlock
Shape the femoral canal and acetabular
cavity for even cement mantle.
Preoperative planning helps.
Preserve the cancellous bone.
Preserve the transverse acetabular
Pre Operative Plan
Brushing and lavage
Brushing – both acetabular and femoral
reduce the loose cancellous bone and
High pressure pulse lavage produce
clean surface. Also prevents circulatory
Both reduce the risk of lamination in the
cement that can decrease the strength
of mantle by 8 -16%
Brushing and Lavage
Pulse lavaging Canal
For good filling and
pressurization; Reabsorbable plugs
5 -8; Improve fixation;
Drilled or Impacted
Entire liquid to polymer powder.
Initial 30 sec – insufficient liquid.
Hairy strands, glistening liquid.
Strands no longer form, shine disappear,
soft dough like consistency, can be
scarped – beginning of working phase.
Vaccum Mixing -prevents air entrapment
in cement, reduces cement porosity,
unbounded particles - strength!
Hand packing – made into rough
cylindrical mass and then packed.
Gun: ensures delivery under pressure.
Inject the cement in retrograde fashion,
letting the cement gun work its own way
out of the femur.
Swedish Hip Registry has shown that
retrograde cement filling using a
cement gun in the femur reduces risk of
Involves use of Cement Gun, special
pressurizers, and centralizers.
Afford greater penetration into
cancellous bone ensuring micro – lock.
Optimal viscosity is key to good
Femur -Marrow extrusion in the greater
trochanter (the so-called sweating
Cement Other uses
Liquid monomer is highly volatile,
flammable, powerful lipid solvent.
Avoid contact of the liquid with surgical
gloves, skin or mucous membranes.
Fumes -irritation of the respiratory tract,
eyes, liver; hypersensitivity, contact
Contact Lenses: reactions between
monomer vapors and soft contact
Word of Caution!
Premature insertion of bone cement ->
drop in BP, arrhythmias or ischemia.
Expulsion of bone marrow –PE; esp
Osteoporotic, NF # &
Inform Anaesthetist prior to cementing –
Hypotensive episode lasts between 30
sec to 5 min.
Expecting the unexpected
“You can handle anything if you think
you can. Just keep your cool and your
sense of humor."
8 stations – 4 cement guns, 4 hand
Both hand mixing and use of gun.
Allocate jobs – mixing, insertion of
cement restrictor, cement delivery,