To The Editor:
It was with great interest that I read "Simultaneous Femoral
Osteotomy and Total Knee Arthroplasty for Treatment of Osteoarthritis Associated
with Severe Extra-Articular Deformity" (82-A: 342-348, March 2000),
by Lonner et al.
We have seen three cases in which patients with considerable
femoral deformities required corrective osteotomy in the same setting
as total knee arthroplasty. We used to fix the osteotomy site with
a multihole retrograde intramedullary nail because we believe in
the mechanical advantage of intramedullary fixation and because such
fixation avoids additional soft-tissue stripping further than the
usual arthroplasty exposure.
Unfortunately, two of the nails broke through the empty screw-holes.
These holes had been left empty due to their close proximity to
the osteotomy line. In the revision setting, removal of the broken
nails was extremely difficult, and, in one case, it was impossible.
Both of the cases were posttraumatic deformities with sclerotic bone
segments, and healing of the osteotomy site was delayed more than
five months despite grafting. I would like to stress that in such
cases with inadequate bone quality, five-hole nails with a solid
segment should be chosen and effort should be expended to fill the
nearest screw-holes. Multihole nails and external plates should be
avoided due to their mechanical disadvantage. Additionally, external
braces should be used until eventual healing ensues.
Bulent Atilla, M.D.
Hacettepe University Medical Faculty
Department of Orthopaedics and Traumatology
Samanpazari 06100
Ankara, Turkey
J. H. Lonner, J. M. Siliski, and P. A. Lotke reply:
We appreciate Dr. Atilla's interest in our article. As Dr. Atilla
appropriately points out in his letter, osteoarthritis of the knee
with severe ipsilateral femoral deformity is a challenging clinical entity.
Dr. Atilla brings to light an important issue that cannot be overlooked
when using a retrograde intramedullary nail to stabilize the femoral
osteotomy. First, the retrograde intramedullary nail is not an option
in cases in which distal femoral bone stock is so severely compromised
that fixation of the distal interlocking screws would be inadequate.
However, when corrective osteotomy is performed in the proximal
aspect of the distal metaphysis or in the diaphysis, retrograde
intramedullary nail fixation is a wonderful option because of its
biomechanical advantage in providing load-sharing and in limiting
vascular compromise of the periosteum and surrounding soft tissues
that might occur with plate fixation. The distal tip of the nail
must overlap the proximal edge of the anterior flange of the femoral
component to avoid a stress fracture.
In the cases described in our report and in a number of cases
treated subsequently, we have found that we must often downsize
the width of the retrograde nail because malalignment in the shaft of
the femur as a result of the osteotomy can eliminate the option
of a tight press-fit nail. Downsizing the nail weakens the construct,
and postoperative rehabilitation must be meticulously supervised
to avoid nail breakage. In light of this, it is important that an
early-generation supracondylar nail with multiple holes be avoided after
elective femoral osteotomy, as it is in supracondylar femoral fractures.
Multiholed nails have been plagued by fracture and nail breakage through
the screw-holes1. A solid segment retrograde femoral nail, with
small proximal and distal interlocking holes, is generally preferred, as
nail breakage is less common. When fixation is adequate, we have
been able to encourage immediate partial weight-bearing with appropriate range
of motion, with or without the use of a hinged knee brace.
Once again, we would like to thank Dr. Atilla for his important
commentary.
Jess H. Lonner, M.D.
John M. Siliski, M.D.
Paul A. Lotke, M.D.
Corresponding author: Jess H. Lonner, M.D.
Department of Orthopaedic Surgery
University of Pennsylvania Medical Center
3400 Spruce Street
Two Silverstein
Philadelphia, Pennsylvania 19104-4283