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Persona The Personalized Knee
Surgical Technique
Surgical Technique
Successful total knee arthroplasty depends in part on
re-establishment of normal lower extremity alignment,
proper implant design and orientation, secure implant
fixation, and adequate soft tissue balancing and
stability. Persona The Personalized Knee is designed to
help the surgeon accomplish these goals by combining
alignment accuracy with a simple, straight-forward
technique.
The instruments and technique assist the surgeon in
restoring the center of the hip, knee, and ankle to lie
in a straight line, establishing a neutral mechanical
axis. The femoral and tibial components are
oriented perpendicular to this axis. Femoral rotation
is determined using the posterior condyles, the
epicondylar axis, or Whiteside’s line as a reference.
The instruments enable accurate cuts to ensure robust
component fixation.
A wide variety of component sizes, shapes, and
constraint options allow for optimized component fit
and soft tissue balancing. The femur, tibia, and patella
are prepared independently, and can be cut in any
sequence using the principle of measured resection
(removing enough bone to allow replacement by the
prosthesis). Adjustment cuts may be needed later. The
anterior referencing technique uses the anterior cortex
to set the A/P position of the femoral component. The
posterior condyle cut is variable.
Constraint Options
The degree of constraint of the bearing can be
planned based on surgeon preference and patient
requirements. The use of the cruciate retaining (CR)
femoral provisionals and components can be used with
either a CR or Medial Congruent
®
(MC) bearing when
the posterior cruciate ligament (PCL) is intact.
The CR femoral provisionals and components can
be used when the PCL is sacrificed or deficient and
removed, if used with either a MC or ultracongruent
(UC) bearing provisionals and components.
Also, posterior stabilized (PS) femoral provisionals and
components can be used with the PS or constrained
posterior stabilized (CPS) bearings provisionals and
components when the PCL is deficient and removed.
PS femoral components cannot be used with CR, MC,
or UC bearings and CR femoral components cannot be
used with PS or CPS bearings.
The CPS bearings can be used to provide moderate
varus\valgus constraint in patients to facilitate soft
tissue balance and stability. The CPS bearings shall
be used with cemented non-porous femoral and tibial
components only. Additional information for this
product may be found in the Constrained Posterior
Stabilized (CPS) Surgical Technique (97-5026-072-00).
The MC, UC, PS, and CPS implants can be used in
the following situations, depending on the degree
of the deformity, the stability of the ligaments, and
the quality of the bone. The surgeon is responsible
for assessing whether a more constraining implant/
system or revision implant/system is necessary.
1.
Marked valgus deformity
– requiring PCL
and lateral soft tissue release.
2.
Prior high tibial osteotomies
– soft tissue
balancing is the same as for a valgus deformity
with lateral soft tissue and PCL release.
3.
Patellectomy
– PCL incomplete or absent.
4.
Most revision situations
– PCL deficient
or nonfunctional.
Introduction
