14 |
Persona The Personalized Knee
Surgical Technique
Resect Proximal Tibia
(cont.)
Position Alignment Guide
To improve the exposure of the tibial surface, retract
the tibia anteriorly. Carefully position the retractor
against the posterior cortex of the tibia subperiosteally
to prevent neurovascular injury. Retract the patella
laterally. Adjust the EM alignment guide to the
approximate length of the tibia. Place the spring arms
of the EM ankle clamp around the ankle proximal to
the malleoli. Align the vertical slot in the cut guide with
the medial third of the tibial tubercle.
Technique Tip:
Care should be taken when pinning
into the tibia to avoid perforating the posterior cortex.
Adjust the height of the cut guide to the approximate
desired location. Use the engraved line on the top of
the cut guide to align the rotational and M/L placement
guide (Figure 20b). A 3.2 mm pin or screw may be
inserted through the 12 mm vertical slot in the cut
guide to secure the desired M/L and rotational position
of the proximal portion of the guide (Figure 20a).
Note:
This pin will need to be removed to allow the
"+2" or "+4" mm shifts with the cut guide.
Align the EM alignment guide with the mechanical
axis of the tibia (Figure 21a). The longitudinal axis will
usually lie just medial to the mid-point of the tibial
tubercle and be centered in line with the intercondylar
eminence. The distal end of the EM alignment guide
should be positioned about 5 mm–10 mm medial to
the midpoint between the palpable medial and lateral
malleoli. The short vertical engraved lines on the
varus/valgus adjustment rail are incremented by 5
mm to aid in setting the desired varus/valgus position
of the EM alignment guide (Figure 21b). Excessive soft
tissue or poor exposure or visualization can make it
difficult to palpate bony landmarks so care should be
taken to ensure accurate cuts.
Figure 20b
Figure 21b
Figure 20a
Figure 21a
AP Axis
5 mm
3.2 mm x 75 mm Trocar Tipped Drill Pin
(2.5 mm hex)
00-5901-020-00
Pin Screw Inserter
00-5901-021-00
Persona Tibial Cut Guide
Right - 7°
42-5399-052-07
Persona EM Proximal Tube
42-5399-001-00
Persona EM Distal Rod
42-5399-002-00
Persona EM Ankle Clamp
42-5399-003-00
3.2 mm Drill
00-5120-085-00