Total hip replacement for developmental hip dysplasia
is challenging. The anatomical deformities on the acetabular and
femoral sides are difficult to predict. The Crowe classification
is usually used to describe these cases – however, it is not a very
helpful tool for pre-operative planning. Small acetabular components,
acetabular augments, and modular femoral components should be available
for all cases. Regardless of the Crowe classification, the surgeon must
be prepared to perform a femoral osteotomy for shortening, or to
correct rotation, and/or angulation. Cite this article:
Smart trials are total knee tibial trial liners
with load bearing and alignment sensors that will graphically show quantitative
compartment load-bearing forces and component track patterns. These
values will demonstrate asymmetrical ligament balancing and misalignments
with the medial retinaculum temporarily closed. Currently surgeons
use feel and visual estimation of imbalance to assess soft-tissue
balancing and tracking with the medial retinaculum open, which results
in lower medial compartment loads and a wider anteroposterior tibial
tracking pattern. The sensor trial will aid the total knee replacement
surgeon in performing soft-tissue balancing by providing quantitative
visual feedback of changes in forces while performing the releases
incrementally. Initial experience using a smart tibial trial is
presented.
The use of short stems has become more popular
with the increased interest in less invasive approaches for total hip
arthroplasty. The curved broaches and stem can be inserted along
a curved track to avoid the abductor attachments. Short stems have
the potential of being more bone conserving by allowing for higher
neck retention, maintenance of the medial greater trochanter, and
preferential stress transfer to the proximal femur. An initial experience with 500 new short stems (Fitmore, Zimmer
Orthopedics) stems used for total hip arthroplasty is reported.
No stems have been revised for aseptic loosening.
