49
48
1
2
3
4
20˚
cAsEs oF pRoXimAL humERAL BoNE Loss
cases of proximal bone loss should be treated using
monobloc cemented humeral implants to avoid any risk
of component dissociation. Long monobloc stems may be
required in some cases.
The preparation of the humeral canal for long stems uses
the same technique described for standard stems, with
the exception of the procedure for reaming the humeral
canal, which differs in this respect: the entire length of the
cutting flutes should be passed down the intramedullary
canal instead of being stopped at the mark (Figure 90).
A positioning jig is available to hold both the trial long
stem and then the final implant in place at the correct
height and retroversion position.
Tighten the fin clamp on the humeral shaft first using the
3.5 mm screwdriver (yellow handle)
1
(Figure 91). Note
that aligning the retroversion guide pin with the forearm
places the implant in 30° retroversion. Re-adjust the
retroversion of the jig to match 0° to 10° retroversion as
used for the reverse shoulder prosthesis (Figure 92).
place the fin clamp over the vertical height gauge of the
humeral shaft clamp and secure the fin clamp to the
hole in the anterior fin of the prosthesis.
2
place the trial
prosthesis at the appropriate height
3
and tighten the fin
clamp to secure it to the vertical height gauge.
4
check the range of motion. Remove the trial stem leaving
the jig in place. Perform the cementing technique as
described (page 42). Assemble the fin clamp to the middle
hole of the final implant. introduce the definitive stem at
the height determined using the jig.
Figure 90
Figure 91
Figure 92
