To The Editor:
I read with great concern the article entitled, "Failure of LCP
Condylar Plate Fixation in the Distal Part of the Femur"
(2006;88:846-853), by Vallier et al. The authors have attempted to provide a
detailed analysis of the reasons for implant failure, but I believe that this
article falls far short of the intended goal. By definition, these fractures
occurred in the setting of severe soft-tissue injuries, and whether or not one
uses "minimally invasive" operative technique probably will not
affect healing rates under the circumstances described. In addition, four of
the six failures were in patients with type-IIIA open fractures. I believe
that there are some details, not specifically addressed in this small series
of plate failures, that need both recognition and explanation.
All patients who had a failure in this series had comorbidities associated
with the femoral fracture. These comorbidity factors, acknowledged by the
authors, had a high probability of adversely affecting the healing outcome.
Several patients had severe polytrauma, three had initial spanning of the open
fracture with external fixation or had a traumatic condition that precluded
immediate internal fixation, several were obese, one had bilateral distal
femoral fractures, and one had diabetes combined with several other
comorbidities.
Allograft bone was used for primary bone-grafting in three patients at the
time of the index procedure. I have found this to be of absolutely no benefit
in augmenting a measurable callus response in patients with acute distal
femoral fractures.
In these six cases, there was no standard method of determining if
sufficient fracture-healing had occurred before loading the implant. There was
no mention of a protocol for how progressive weight-bearing was begun, and
there was no standard periodic follow-up with clinical or radiographic
evaluation after weight-bearing was initiated. The authors state that the
patients were allowed progressive weight-bearing at a certain period of time
postoperatively in the presence of radiographic evidence of "some
healing". In every case, these patients were not followed at routine
intervals to assess the effect of this "progressive
weight-bearing" and whether or not weight-bearing was detrimental to
fracture-healing. The follow-up intervals after initial weight-bearing was
begun varied between 1.5 and ten months and seemed to occur only when patients
returned with symptoms. Implant loosening, deformity, or plate fatigue was
then diagnosed by the operating surgeon. Although failures were attributed by
the authors to the implant and the technology, they may in fact be more
directly related to a lack of appropriate management of weight-bearing status,
the failure of early detection of implant loosening, or the absence of
aggressive intervention by the operating surgeon to modify or alter the
healing process.
Of note, only two of these six "implant failures" required
revision surgery; four other "plate failures" healed. These two
implant fatigue failures occurred at nine and fourteen months postoperatively,
after prolonged periods of what one can only assume was full weight-bearing on
ununited fractures. I reviewed the figures presented by the authors and do not
believe that these failures can be attributed to the failure of locked plate
fixation (see Appendix).
There are major problems with this kind of report, and it is of concern
that this report was accepted by The Journal without further scrutiny
as to causes of failure. The radiographs of one patient (Case 6) were
misinterpreted (see Appendix), suggesting potential errors in the
interpretation of the rest of the data. Why were these patients allowed
progressive weight-bearing when radiographs revealed only "some
healing," and why were they then not followed more closely to assess the
presence or absence of further healing? If impending failure had been detected
earlier in these patients, would the authors have intervened surgically at
that time?
I believe that all implant failures in this series were due to progressive
weight-bearing on ununited fractures before adequate healing was achieved. I
do not find evidence that implant failure was the sole cause of these
complications. The authors referenced two series that involved the use of
locking-plate technology in which the rates of implant loosening or screw
breakage were between 5% and 18%. The treatment of difficult fractures in
less-than-optimal situations in which weight-bearing on plate implants is
allowed before sufficient healing occurs is not a technique or implant design
error, but rather, is a management error. The lack of more closely monitored
follow-up after the initialization of weight-bearing was a major reason for
failure in these patients. The failure to recognize subtle signs of implant
loosening and misinterpreting these as signs of "progressive
healing" also contributed to the ultimate failure in these six patients.
In addition, the lack of an aggressive implant exchange or autogenous graft
augmentation when early signs of implant loosening were present may have also
contributed to these failures. Locking Condylar Plate (LCP) technology is an
attempt to bridge our capability to stabilize more extreme fractures. It has
great potential but is not a 100% successful implant and, like any other
implant, requires the surgeon to use the art of surgery to manage the
postoperative environment surrounding the plate to maximize the healing
potential. Finally, I would note that the treatment of these fractures
requires attention to detail and experience that seem to matter more than
whether or not one has achieved the status of a fellowship-trained trauma
orthopaedist in a level-I trauma center.