Lisfranc joint injuries (tarsometatarsal dislocations or
fracture-dislocations) are uncommon, and they are frequently missed or
misdiagnosed1-4.
However, even with accurate diagnosis and early treatment, these injuries can
result in chronic
disability5. Over
the past several decades, Lisfranc complex injuries have been treated with
closed reduction and immobilization, closed reduction and percutaneous
pinning3,6-9,
or open reduction and percutaneous pinning or screw
fixation10-13.
It has become evident that an anatomic reduction is critical for optimal
outcomes and that this is best achieved with open
reduction7,11-13.
However, the method of treatment is still controversial. Currently, the
recommended and accepted treatment of Lisfranc complex injuries is open
reduction and internal
fixation10-13,
but, despite appropriate initial treatment, painful osteoarthrosis still
develops in some
patients3,8,
necessitating conversion to an arthrodesis of the tarsometatarsal joints to
achieve pain relief.
According to the current literature, primary arthrodesis is not recommended
for Lisfranc complex
injuries9,11.
Instead, arthrodesis has been reserved as a salvage procedure after failed
open reduction and internal fixation, for a delayed or missed diagnosis, and
for severely comminuted intra-articular fractures of the tarsometatarsal
joints7,11,14-17.
Kuo et al.12
suggested that there is a subgroup of patients with a purely ligamentous
Lisfranc injury who may be better treated with primary fusion. More recently,
Mulier et al.10
compared the results of primary arthrodesis with those of open reduction and
internal fixation for severe Lisfranc injuries in a retrospective,
surgeon-randomized study. They advocated open reduction and internal fixation
or partial arthrodesis for severe Lisfranc injuries, believing that primary
complete arthrodesis should be reserved as a salvage procedure.
The purpose of the present prospective study was to test the hypothesis
that treatment of high-energy ligamentous Lisfranc injuries with primary open
reduction and internal fixation would have the same or better functional short
and medium-term outcomes as treatment with a primary partial arthrodesis.
We performed a prospective study comparing two groups of patients with a
Lisfranc joint injury. The study design was to include all injuries that were
seen up to one month after the accident, although all forty-one patients had
the surgery within three weeks from the date of injury and most had it within
the first week. The Lisfranc joint injury had to be primarily ligamentous,
with no major fractures present (Fig.
1-A). Lisfranc joint injuries with a fleck sign (an avulsion
fracture of the Lisfranc ligament) were considered to be primarily ligamentous
and were included in the study. Exclusion criteria were a comminuted
intra-articular fracture at the base of the first or second metatarsal; any
other substantial foot, ankle, or leg injury; a previous attempt at surgical
management of the same injury; insulin-dependent diabetes mellitus;
ipsilateral ankle fusion; peripheral vascular disease; peripheral neuropathy;
and rheumatoid arthritis.
Between March 1998 and January 2002, forty-one patients who met the
inclusion criteria were enrolled in the study; this was a consecutive series
as no patient refused to participate in the study. The study was approved by
our institutional review board (IRB-0212M37742), and informed consent was
obtained from the patients. All patients had been followed for at least two
years. A power analysis done before the study showed that we needed
thirty-eight patients to demonstrate a significant difference between the two
groups with regard to the American Orthopaedic Foot and Ankle Society (AOFAS)
Midfoot Scale scores. This number represented a power of 0.8.
Patients were randomized with use of an odd-or-even process, based on the
order of presentation, to the arthrodesis group or the open-reduction group as
they presented with the Lisfranc joint injury. For example, the first patient
was assigned to the arthrodesis group, and the next patient was automatically
assigned to the open-reduction group. There was no variation from this
protocol at any time during the study. Patients in the arthrodesis group were
treated with primary arthrodesis of the medial two or three rays, depending on
the instability pattern. If the radiographs and computed tomography scan
showed an instability pattern that involved the first and second
metatarsal-cuneiform joints but no instability of the third, only the medial
two rays were fused. However, if the third metatarsal-cuneiform joint was
displaced, it was reduced and fused as well. Three patients also had
instability between the medial and middle cuneiforms, and that joint was
included in the fusion. The first metatarsal-cuneiform joint was fused in all
but one patient, in whom only the second and third metatarsal-cuneiform joints
were fused. If the radiographs and computed tomography scan showed a
subluxation or dislocation of the lateral two rays, they were assessed under
fluoroscopy after treatment of the medial rays. If they appeared to be well
reduced and stable, no treatment was provided. If there was still a
malreduction or if they were unstable with manipulation, the fourth and fifth
rays were reduced and were stabilized with temporary Kirschner-wire fixation,
but they were not fused. The Kirschner wires were removed at six weeks.
Autogenous bone graft or allograft was not utilized in the primary arthrodesis
group.
Patients in the open-reduction group were treated in the conventional way
with formal open reduction and internal fixation, which was done with screw
fixation of the medial two or three rays. The indications for Kirschner-wire
fixation of the lateral two rays were exactly the same as those in the
arthrodesis group. The lateral two rays were not fused in any of the forty-one
patients. Standard 3.5 or 4.0-mm cortical screws were utilized depending on
the patient's size.
Postoperative follow-up was performed at two weeks, six weeks, three
months, and six months, and then annually. We evaluated the outcomes with
clinical examination, radiography, a visual analog pain scale (of 0 to 10),
the AOFAS Midfoot
Scale18, and a
clinical questionnaire. Alignment was assessed on weight-bearing
anteroposterior, lateral, and oblique radiographs, which were made at each
follow-up visit except for the one at two weeks. Alignment was assessed on the
basis of whether the medial border of the second metatarsal lined up with the
medial border of the middle cuneiform on the anteroposterior radiograph,
whether the medial border of the fourth metatarsal lined up with the medial
border of the cuboid on the oblique radiograph, and whether there was any
dorsal displacement of the metatarsals relative to the tarsal bones on the
lateral radiograph. The clinical questionnaire included questions regarding
patient satisfaction (dissatisfied, somewhat dissatisfied, neutral, somewhat
satisfied, or very satisfied) with the treatment and questions regarding their
return to their previous level of physical or sports activities. In addition,
the patients were asked to estimate their level of activities as a percentage
of the level before the injury. Finally, the patients were asked to rate the
pain on a visual analog pain scale that ranged from 0 (no pain) to 10 (severe
pain).
Open-Reduction Group
There were twenty patients, thirteen men and seven women, in the
open-reduction group. Twelve patients were injured in a motor-vehicle,
snowmobile, or all-terrain-vehicle accident. Five patients fell from a height
of >4 ft (>1.2 m). One patient was playing basketball when another
player fell on his foot. Another patient was injured in a pile-up in an ice
hockey game, and one patient stepped into a 2-ft (0.6-m) deep hole in the
ground. The average age at the time of injury in this group was 32.4 years
(range, nineteen to fifty-two years), and the average duration of follow-up
was forty-two months (range, twenty-five to sixty months).
Arthrodesis Group
There were twenty-one patients, fourteen men and seven women, in the
arthrodesis group. Ten patients were injured in a motor-vehicle, snowmobile,
or dirt-bike accident. Seven patients fell from a height of >4 ft (>1.2
m). Two patients fell off a horse while the foot was stuck in the stirrup, and
two patients stepped into a deep hole. The average age at the time of injury
was thirty-two years (range, nineteen to forty-two years), and the average
duration of follow-up was 43.4 months (range, twenty-five to sixty
months).
Surgical Technique
Open Reduction and Internal Fixation
Two dorsal longitudinal incisions—one between the first and second
metatarsals and the second centered between the fourth and fifth
metatarsals—were made. Open reduction and screw fixation of the first,
second, and third metatarsal-cuneiform joints was performed
(Fig. 1-B). Then, if necessary,
Kirschner wires were placed in each of the lateral two rays, but the rays were
not fused. Seven patients in the open-reduction group required Kirschner-wire
fixation of the lateral rays. The Kirschner wires were removed between six and
eight weeks postoperatively. The screws were not routinely removed unless they
caused symptoms, and they were never removed before three months.
Arthrodesis
Standard incisions were made as described for the open-reduction group.
Open reduction was performed, cartilage and fibrous tissue were resected, and
the joints were decorticated. Reduction and screw fixation was then performed.
If the third metatarsal-cuneiform joint was seen to be displaced on the
computed tomography scan or was clearly unstable on direct examination, it was
fused in the same fashion. The rationale for treatment of the lateral two rays
was exactly the same as the rationale in the open-reduction group. Nine
patients in the arthrodesis group underwent temporary Kirschner-wire fixation
of the lateral two rays.
Postoperative Management
Postoperatively, all patients wore a short leg splint for two weeks
followed by a short leg cast for four to six weeks, and all remained
non-weight-bearing during this time. The patients then slowly advanced to full
weight-bearing over the next four weeks while wearing a prefabricated fracture
boot. Physical therapy was started at svix to ten weeks and included
gait-training, swelling control, and range-of-motion exercises.
Over-the-counter or custom-made orthotics were prescribed on an as-needed
basis, depending on residual symptoms.
Statistical Analysis
GraphPad InStat software (GraphPad Software, San Diego, California) was
used to perform the statistical analysis for the study. The Mann-Whitney test
was used to derive an unpaired two-tailed p value. A p value of <0.05
indicated significance.
Open-Reduction Group
Complications and Additional Surgery
Of the twenty patients in the open-reduction group, sixteen underwent
secondary surgery to remove prominent or painful hardware. The screws were
removed at an average of 6.75 months (range, three to sixteen months).
Follow-up radiographs showed evidence of loss of correction, increasing
deformity, and degenerative joint disease in fifteen patients
(Fig. 1-C). Five of these
patients required conversion to tarsometatarsal arthrodesis at an average of
thirty-five months (range, fourteen to sixty months) after the injury. Two
more patients were scheduled for conversion to an arthrodesis at the time of
manuscript preparation.
Functional Questionnaire
We present the functional results that were determined at the most recent
follow-up evaluation. The results for the patients who underwent a secondary
fusion were determined at the last follow-up visit prior to the fusion.
Eight patients reported that they were very satisfied with the result,
three were somewhat satisfied, three were neutral, and six were dissatisfied
(Table I). Five of the six
patients who were dissatisfied with the outcome went on to have a
tarsometatarsal fusion. All five later reported that they were very satisfied
with the result at the time of the last follow-up. Six of the twenty patients
reported that they were able to return to their preinjury level of physical or
sports activities, and fourteen stated that they were not able to do so. On
the average, the patients estimated their return to physical or sports
activity, as a percentage of the preinjury level, to be 44% at the six-month
postoperative visit, 61% at the one-year visit, and 65% at the two-year visit
(Table II).
Arthrodesis Group
The arthrodesis group as a whole did very well. Anatomic reduction was
obtained in twenty of the twenty-one patients. The average time to fusion was
10.6 weeks. Nineteen patients had an uncomplicated fusion, one needed
treatment with a bone stimulator, and one required bone-grafting and revision
fusion. Twelve patients had three rays fused, and nine had two rays fused;
there was no difference in outcome between these two subgroups.
Complications and Additional Surgery
Of the twenty-one patients in the arthrodesis group, four (19%) required a
second surgical procedure, primarily for removal of painful hardware. The
screws were removed at an average of 6.5 months (range, five to ten months).
One patient had a delayed union at seventeen weeks; a bone stimulator was
used, and a solid fusion was achieved over the next eight weeks. One patient
with a nonunion at twenty weeks underwent a revision arthrodesis with bone
graft from the calcaneus. The fusion healed uneventfully at eight weeks after
the revision surgery. Another patient had a posttraumatic intrinsic
compartment syndrome that resulted in clawtoes. This patient underwent
percutaneous flexor tendon release of the lesser toes and was pleased with the
result.
Functional Questionnaire
Sixteen patients reported that they were very satisfied with the result,
and five were somewhat satisfied (Table
I). Fifteen patients reported that thvey were able to return to
their previous level of physical or sports activities, and six stated that
they were unable to do so. The patients' estimation of their return to
physical and sports activity, as a percentage of the preinjury level, averaged
62% at six months postoperatively, 86% at one year, and 92% at two years
(Table II).
AOFAS Midfoot Scores and Visual Analog Pain Scores
At the time of the two-year follow-up, the AOFAS score averaged 88.0 points
(range, 63 to 100 points) in the arthrodesis group and 68.6 points (range, 16
to 100 points) in the open-reduction group (p = 0.005). At the time of final
follow-up (at an average of forty-two months in the open-reduction group and
forty-three months in the arthrodesis group), the AOFAS Midfoot score averaged
57.1 points (range, 16 to 100 points) in the open-reduction group (including
the five patients who had undergone conversion to a tarsometatarsal
arthrodesis) and 86.9 points (range, 63 to 100 points) in the arthrodesis
group (p < 0.0001). When the five patients in the open-reduction group who
had had a conversion to midfoot arthrodesis were excluded, the average final
AOFAS Midfoot score for the remaining fifteen patients was 65.2 points (range,
27 to 100 points), and the arthrodesis group still had a better average score
than the open-reduction group (p < 0.0024).
As stated, five of the patients who were originally treated with open
reduction and internal fixation had a conversion to a fusion. Three of the
four who had the arthrodesis more than two years before our review were
available for evaluation. Their mean AOFAS score at two years was 79.0 points,
which was better than the mean for the open-reduction group but lower than
that for the primary arthrodesis group. These four patients' mean estimate of
their functional ability after the fusion was 80% of their preinjury level.
The number of patients in this subgroup is too small for us to draw any
conclusions, but the findings show a trend toward improvement after secondary
fusion but results that are not as good as those following a primary
fusion.
At the time of final follow-up, the average score on the visual analog pain
scale was 4.1 points in the open-reduction group and 1.2 points in the
arthrodesis group (p = 0.0002).
Treating intra-articular fractures and dislocations poses unique
challenges. It is important to look at every joint's function specifically
when deciding which treatment options are realistic. For example, a fusion of
the knee is very seldom used, even as a salvage procedure, for the treatment
of a distal femoral fracture. In contrast, feet with a Lisfranc joint fracture
are often salvaged with a fusion, without a devastating effect on function.
However, we are not aware of any prospective studies in the literature
focusing on the issue of primary fusion or comparing fusion with open
reduction and internal fixation for Lisfranc joint injuries, although it is
evident from the literature that the results of open
reduction7,11-13
are better than those of closed reduction and that screw fixation is better
than percutaneous
pinning3,6,7,9-13,
at least for the medial three rays. Recently, most authors have recommended
open reduction and internal fixation instead of primary arthrodesis for
Lisfranc joint
injuries9-13.
However, because persistent pain and posttraumatic degenerative changes occur
despite anatomic
reduction3,8,
we speculated that there may be a subset of Lisfranc injuries that are better
treated with primary arthrodesis of the involved tarsometatarsal joints.
Kuo et al.12
pointed out that purely ligamentous Lisfranc injuries do not always heal
following open reduction and internal fixation and that there was a tendency
for this type of injury to result in osteoarthrosis (a finding in six of their
fifteen patients). In our study, fifteen of the twenty patients in the
open-reduction group lost correction and had at least some deformity and
degenerative arthritic changes, which ranged from a minor loss of correction
to substantial collapse and degenerative changes. Five of our patients had
persistent pain and underwent a salvage arthrodesis, and two more patients
were awaiting an arthrodesis at the time of writing. The mean AOFAS Midfoot
score in our open-reduction group (57.1 points) was lower than the mean score
for the patients in the study by Kuo et al. (78.8 points). However, our
arthrodesis group had a better outcome, with a mean AOFAS Midfoot score of
86.9 points. This information suggests that patients with a primarily
ligamentous Lisfranc injury should be treated with primary arthrodesis.
Sixteen of the twenty patients in our open-reduction group had removal of
hardware, and we believe that that was a confounding factor for the poor
results seen in that group. However, we also believe that the injury itself,
being primarily ligamentous, plays a major part in the healing and outcome of
these injuries. A review of the radiographs made prior to hardware removal
indicated that some early degenerative changes and collapse of the midfoot had
developed in the majority of patients. Radiographs made at a later follow-up
visit showed that most of the patients went on to have progressive
degenerative changes after the screws were removed. We postulate that, because
these injuries were primarily ligamentous, healing of the ligaments and
capsules provided insufficient strength to maintain the initial reduction.
This is evidenced by the fact that, despite initial anatomic reduction in
eighteen of the twenty patients, some loss of correction, further collapse,
and degenerative changes of the Lisfranc joint developed after screw removal
in fifteen patients.
Recent
studies10,14,16
have compared complete and partial arthrodeses for the treatment of Lisfranc
joint injuries, and we found one study comparing open reduction and internal
fixation with primary arthrodesis. In that surgeon-randomized study of
twenty-eight patients, which had some similarities to our study, Mulier et
al.10 compared open
reduction and internal fixation (sixteen patients) with complete arthrodesis
(six patients) and partial arthrodesis (six patients). They concluded that a
complete fusion (of all five tarsometatarsal joints) yields poor results and
that open reduction and internal fixation provides a better functional
outcome. We agree with that conclusion. Mulier et al. reported that, at the
time of final follow-up (at thirty months), 94% of their open-reduction group
already had radiographic signs of degenerative changes of the tarsometatarsal
joints. At that juncture, the open-reduction group had the same functional
score as the group treated with partial fusion, but it can be assumed that the
score in the open-reduction group would decrease with time because of the high
rate of identified degenerative changes.
The authors of two previous studies recommended that only the medial two or
three rays be fused. We concur with Komenda et
al.14 and
Sangeorzan et al.16
that it is beneficial for a patient to have motion in the lateral two rays and
that it is not necessary to perform a complete fusion to obtain optimum
results. Komenda et al. reported the results of arthrodeses that were
performed to treat intractable pain at a mean of thirty-five months after
traumatic tarsometatarsal joint injury. The mean AOFAS Midfoot score was 78
points at a mean of fifty months postoperatively. In our study, the mean AOFAS
Midfoot score in the arthrodesis group was 86.9 points at a mean of 43.4
months postoperatively. This finding suggests that performing immediate
primary fusion helps patients to avoid several years of persistent pain and
disability.
Our study had several limitations. First, the allocation of treatment with
an open-randomization, odd-or-even format could have introduced selection
bias. Using a random-numbers table or computerized randomization would have
been a better way to allocate our patients. Second, the attending surgeon
performed the follow-up clinical examination and gathered the questionnaires,
which raises a concern about bias. However, the patients were given the
questionnaires when they arrived at the clinic and had completed them on their
own by the time that they were seen in the clinic. The attending surgeon just
gathered the forms and made sure that they were entered into the database.
Third, we did not obtain information or determine the outcomes for the
patients with Lisfranc joint injuries who were not included in the study
because they met our exclusion criteria. Outcome information on the patients
with osseous involvement would have provided a group with which to compare our
patients, who had the less common, ligamentous Lisfranc injuries. Fourth,
hardware removal could have contributed to the poor results that were seen in
the open-reduction group.
In summary, because of the poor healing potential of the ligament-osseous
interface and the trend toward a higher rate of correction loss, increasing
deformity, and degenerative arthritic changes, we believe that primarily
ligamentous injuries are a subset of Lisfranc joint injuries that are not as
amenable to internal fixation. We believe that stable arthrodesis is a better
primary treatment for these injuries, with superior short and medium-term
outcomes than those following open reduction and internal fixation. ?