History of the Procedure:
Kulowski first described
tenosynovitis of the posterior tibial tendon (PTT)
in 1936. Key described surgical findings of
partial posterior tibial tendon rupture in 1953.
In 1974, Goldner et al described the surgical
treatment of 9 patients with PTT dysfunction. In
the early 1980s, Jahss (1982), Mann (1982), and
Johnson (1983) recognized PTT dysfunction as a
common cause of acquired adult flatfoot.
Problem:
Adult flatfoot refers to a
deformity that develops after skeletal maturity is
reached. It should be differentiated from
constitutional flatfoot, which is a common
congenital nonpathologic foot morphology.
Etiology:
There are numerous causes
of acquired adult flatfoot, including fracture or
dislocation, tendon laceration, tarsal coalition,
arthritis, neuroarthropathy, neurologic weakness,
and iatrogeny. The most common cause of acquired
adult flatfoot is PTT dysfunction. This article
focusses primarily on the diagnosis and treatment
of this condition.
The etiology of PTT dysfunction
is varied; PTT dysfunction is attributed to
degenerative, inflammatory, and traumatic causes.
In one study, 60% of patients with PTT dysfunction
were found to have obesity, diabetes mellitus,
hypertension, previous surgery or trauma to the
medial foot, or treatment with steroids. Myerson
has described 2 subsets of patients with PTT
dysfunction. One patient group was younger with
associated enthesopathies at multiple sites, a
higher incidence of human leukocyte antigen (HLA)
B27 positivity, and a significant family history
for inflammatory disease and psoriasis, thus
suggesting a seronegative spondyloarthropathy. The
other patient group was older and had isolated PTT
dysfunction, suggesting a purely mechanical
degenerative cause.
Arthropathies can result in PTT
dysfunction as well. In one study, 11% of 99
rheumatoid patients were found to have posterior
tibial tendon pathology. A zone of tendon
hypovascularity exists 1-1.5 cm distal to the
medial malleolus, continuing 14 mm distally. Poor
blood supply in this area of the tendon, where it
takes a sharply curving course around the medial
malleolus, could result in tendon degeneration and
may explain a mechanical cause for tendon rupture.
A study by Dyal et al compared
weightbearing radiographs of symptomatic feet with
PTT dysfunction to those of the contralateral
asymptomatic feet. Interestingly, there was strong
correlation between the measurements of both feet,
leading the authors to suggest that a predisposing
constitutional flatfoot may be a possible
etiologic factor in the development of PTT
dysfunction. The authors cautioned against using
radiographic measurements alone to diagnose PTT
dysfunction.
Pathophysiology:
The
medial longitudinal arch has both passive and
active support. The 3 most important static
contributors to arch stability in order of
importance are the plantar fascia, the long and
short plantar ligaments, and the spring ligament (calcaneonavicular
ligament). The spring ligament forms a sling for
the talar head, which prevents medial and plantar
migration of the talar head and provides static
arch support. The major dynamic stabilizer for the
arch is the posterior tibial tendon.
Contraction of the PTT causes
inversion of the midfoot and elevation of the
medial longitudinal arch through its broad
insertion on the navicular, cuneiforms, medial 3
metatarsal bases, and cuboid.
The PTT also indirectly affects
hindfoot inversion due to its course running
behind the medial malleolus and its close
association with the deep deltoid and spring
ligaments. With hindfoot inversion, the axes of
the talonavicular and calcaneocuboid joints
diverge, and the transverse tarsal joint (Chopart
joint) becomes locked, which transforms the foot
into a rigid lever.
Loss of posterior tibial
function due to stretching or rupture of the
tendon removes the primary inverter of the foot
and leaves the primary and secondary everters of
the foot, the peroneus brevis and longus,
relatively unopposed. Therefore, posterior tibial
dysfunction leads to flattening of the medial
longitudinal arch, forefoot abduction, and
hindfoot valgus. During the late stance phase of
gait, the patient loses push-off strength due to
inability to invert the hindfoot and achieve
forefoot rigidity. With loss of the posterior
tibial tendon function, the powerful
gastroc-soleus complex acts at the talonavicular
joint instead of at the level of the metatarsal
heads.
The talar head is then pushed
downward and medially, stretching the
calcaneonavicular (spring) ligament. Continued
weightbearing on the medial side of the heel
eventually leads to deltoid ligament insufficiency
and valgus instability of the ankle.
Three-dimensional computer tomographic analysis of
patients with acquired flatfoot has documented
subluxation of the subtalar joint with less
contact between all 3 facets of the calcaneus and
talus compared to controls.
Clinical:
The patient with posterior
tibial tendon dysfunction initially complains of
pain and swelling in the medial ankle and midfoot
during weightbearing. Over time, the patient may
notice loss of the arch and the tendency to walk
on the inner border of the foot. Loss of push-off
strength during gait will occur, and the patient
may develop a limp. As the patient's heel
displaces into valgus and the forefoot abducts,
pressure between the calcaneus and fibula may
develop, causing painful impingement between the
lateral ankle and calcaneus. Abnormal wear of the
medial heel and inner border of shoe wear also may
be noted.
The patient is first examined
while standing, allowing comparison of the
symptomatic to the asymptomatic foot. Arch height
is assessed and compared to the asymptomatic foot.
In later stages of PTT dysfunction, the arch is
lowered and the forefoot abducted. Viewing the
patient's foot from behind allows the examiner to
evaluate forefoot abduction and heel valgus. The
toes visible lateral to the heel are counted. One
or 2 toes visible lateral to the heel is normal.
In cases of significant forefoot abduction, 3 or
more toes are visible. This "too many toes" sign
is a test to confirm forefoot abduction
.
The angle that the heel forms
with the longitudinal axis of the lower leg also
should be measured. This posterior tibiocalcaneal
angle is increased in cases of significant heel
valgus. The patient should then be asked to stand
on one foot and rise up on the toes. The patient
usually needs to hold on to the examining table or
wall for balance during this maneuver. Normally,
the heel inverts as the posterior tibial muscle
contracts and as the gastroc-soleus fires. In
cases of PTT dysfunction, the heel will not
invert, and the patient will find this single limb
heel rise maneuver painful, difficult, or
impossible.
The patient then is examined
seated on the examining table, and the course of
the posterior tibial tendon is palpated for
tenderness. Swelling along the PTT sheath may be
noted, and fluid may be palpated within the
sheath. Posterior tibial strength is tested by
holding the forefoot in a position of plantar
flexion and eversion and asking the patient to
invert the foot. During this maneuver, the PTT
should be palpated to assess its continuity. The
sinus tarsi and distal fibular area also should be
palpated for tenderness because in later stages of
PTT dysfunction, these areas of impingement also
may be painful. The knee is extended, the foot is
held in a subtalar neutral position, and passive
ankle dorsiflexion is measured.
Usually, 10-20 degrees of
dorsiflexion is possible, but in cases of
long-standing pes planus, dorsiflexion past
neutral is often limited due to the development of
a plantar flexion contracture. During the final
stages of PTT dysfunction, the subtalar joint may
be fixed in eversion, and inversion to neutral may
be impossible. Finally, forefoot flexibility is
assessed by pronating and supinating the forefoot
while holding the heel in neutral position.
Although the subtalar joint may be flexible, the
transverse tarsal joint may have become fixed in
varus, preventing plantigrade positioning of the
forefoot. This finding will have important
implications for surgical treatment.
Indications for
treatment of posterior tibial tendon dysfunction
are disabling pain, deformity, shoe wear problems,
and difficulty with ambulation. A painless
deformity that can be accommodated by normal
footwear and allows for normal gait does not
require treatment.
Contraindications:
Contraindications
to surgical treatment are active or chronic
infection, open ulceration, and severe peripheral
vascular disease. A relative contraindication to
surgical treatment is peripheral neuropathy with
loss of protective sensation.
Lab Studies:
- Generally, no laboratory
studies are warranted for adult acquired
flatfoot unless a systemic metabolic or
inflammatory condition is suspected.
- A painless, atraumatic
flatfoot deformity in an insensate foot is most
likely due to neuroarthropathy (Charcot foot).
The most common cause of neuroarthropathy in the
United States is diabetes. If diabetes mellitus
is not already diagnosed, a fasting blood
glucose test is indicated.
- If the patient has pain in
multiple joints, consider a workup for
rheumatoid arthritis or seronegative
spondyloarthropathy with rheumatoid factor,
erythrocyte sedimentation rate, and HLA-B27.
Imaging Studies:
- Obtain standing
anteroposterior and lateral radiographs of the
foot and ankle.
- Measurements of the lateral
first talometatarsal angle, calcaneal pitch,
distance from medial cuneiform base to the
floor, and talonavicular coverage angle are
made.
- As a flatfoot deformity
develops, the arch sags at the
naviculocuneiform or talonavicular joint,
causing a decrease in calcaneal pitch, a
decreased lateral first talometatarsal angle,
and depression of medial cuneiform height
.
- The forefoot moves
laterally into abduction, causing lateral
subluxation of the talonavicular joint and an
increase in the talonavicular coverage angle.
- Standing ankle views are
mandatory to exclude ankle valgus instability
as a contributing factor to the heel valgus
and pes planus deformity.
- Tenography has been
utilized to diagnose PTT rupture with limited
success.
- Five cc of radio-opaque dye
is injected into the sheath between the medial
malleolus and navicular tuberosity. In later
stages of dysfunction, the tendon and sheath
become adherent, and injection of dye becomes
impossible. Following tendon rupture, the
sheath often is not palpable, and injection is
very difficult.
- In one study, tenography
could only successfully be performed in 1 out
of 6 patients.
- Magnetic resonance imaging
- MRI is helpful in
diagnosing PTT dysfunction, but it is not
required to make the diagnosis.
- Conti et al utilized MRI to
describe 3 types of PTT degeneration. A type I
finding is a partially torn tendon with tendon
enlargement and vertical splits. Type II is a
partially torn attenuated tendon. A type III
finding is a complete rupture with a tendon
gap.
- Although very sensitive,
MRI was found to overestimate the degree of
tendon degeneration based on surgical
findings, with a mere 40% correlation between
MRI and surgical findings. This MRI
classification was useful in predicting the
outcome of tendon transfer, with higher grades
of tendon degeneration faring worse than mild
grades of degeneration.
Staging:
Johnson and Strom
described 4 stages of posterior tibial tendon
dysfunction. These stages are utilized to dictate
treatment.
- Stage 1 is characterized by
peritendinitis and tendon degeneration, but the
tendon length remains normal. This stage
presents clinically as pain and swelling along
the posterior tibial tendon sheath.
- In Stage 2, the posterior
tibial tendon elongates, and a supple flat foot
deformity develops. Although deformed on
weightbearing, the hindfoot and midfoot
deformities are passively correctable to
neutral.
- Stage 3 occurs over time as
the hindfoot becomes rigid in a valgus position,
and the patient develops a rigid flatfoot
deformity.
- Stage 4 develops as the
deltoid ligament becomes incompetent and the
talus tilts into valgus within the ankle
mortise.
Medical therapy:
Medical or nonoperative
therapy for PTT dysfunction involves rest,
immobilization, nonsteroidal anti-inflammatory
medication, physical therapy, orthotics, and
bracing. This treatment is especially attractive
for patients who are elderly who place low demands
on the PTT and who may have underlying medical
problems that may preclude operative intervention.
During stage 1 PTT dysfunction,
pain, rather than deformity, predominates. Cast
immobilization is indicated for acute
tenosynovitis of the posterior tibial tendon or
for patients whose main presenting feature is
chronic pain along the tendon sheath. A
well-molded short leg walking cast or removable
cast boot should be used for 6-8 weeks.
Weightbearing is permitted if
the patient is able to ambulate without pain. If
improvement is noted, the patient then may be
placed in custom full-length semirigid orthotics.
The patient may then be referred to physical
therapy for stretching of the Achilles tendon and
strengthening of the posterior tibial tendon.
Steroid injection into the posterior tibial tendon
sheath is not recommended due to the possibility
of causing a tendon rupture.
In stage 2 dysfunction, a
painful flexible deformity develops, and more
control of hindfoot motion is required. In these
cases, a rigid University of California at Berkley
(UCBL) orthosis or short articulated ankle-foot
orthosis is indicated.
Once a rigid flatfoot deformity
develops, as in stage 3 or 4, bracing is extended
above the ankle with a molded ankle-foot orthosis
(AFO), double upright brace, or
patellar-tendon-bearing brace. The goals of this
treatment are to accommodate the deformity,
prevent or slow further collapse, and improve
walking ability by transferring load to the
proximal leg away from the collapsed medial
midfoot and heel.
Nonoperative therapy for PTT
dysfunction has been shown to yield 67%
good-to-excellent results in 49 patients with
stage 2 and 3 deformities. A rigid UCBL orthosis
with a medial forefoot post was utilized in
nonobese patients with flexible heel deformities
correctible to neutral and less than 10 degrees of
forefoot varus. A molded ankle foot orthosis was
used in obese patients with fixed deformity and
forefoot varus greater than 10 degrees. Average
length of orthotic use was 15 months. Four
patients ultimately elected to have surgery. The
authors concluded that orthotic management is
successful in older low-demand patients and that
surgical treatment can be reserved for those
patients who fail nonoperative treatment.
Table 1. Summary of Conservative
Treatment
| Stage |
Treatment |
| Stage 1 |
NSAIDs, short-leg walking
cast or walker boot for 6-8 wk
Full-length semirigid custom molded orthosis,
physical therapy |
| Stage 2 |
UCBL orthosis or short
articulated ankle orthosis |
| Stage 3 |
Molded AFO, double upright
brace, patellar tendon bearing brace |
| Stage 4 |
Molded AFO, double upright
brace, patellar tendon bearing brace |
Surgical therapy:
Surgical treatment of stage 1
PTT dysfunction
If initial conservative therapy
of PTT insufficiency fails, surgical treatment is
considered. Operative treatment of stage 1 disease
involves release of the tendon sheath,
tenosynovectomy, debridement of the tendon with
excision of flap tears, and repair of longitudinal
tears. A short-leg walking cast is worn for 3
weeks postoperatively. Teasdall and Johnson
reported complete relief of pain in 74% of 14
patients undergoing this treatment regimen for
stage 1 disease. Surgical debridement of
tenosynovitis in early stages is believed to
possibly prevent progression of disease to later
stages of dysfunction.
Surgical treatment of stage 2
PTT dysfunction
Treatment of the flexible
deformity of stage 2 PTT dysfunction is
controversial. Direct repair of the torn tendon,
tendon transfer or tenodesis using flexor
digitorum longus (FDL) or flexor hallucis longus (FHL),
spring ligament repair, medial displacement
calcaneal osteotomy, lateral column lengthening,
and limited arthrodeses of the hindfoot or midfoot
have all been reported to yield satisfactory
outcomes. Achilles tendon lengthening is
recommended if ankle dorsiflexion is limited to 10
degrees or less. The difficulty in obtaining an
excellent surgical result is evidenced by the
multitude of surgical procedures proposed for
stage 2 dysfunction.
Direct repair
The torn tendon may be directly
repaired by suturing the ends of an acute rupture.
If the tendon is avulsed distally, it can be
repaired to the navicular, or the portion of the
tendon that is attenuated can be excised and the
proximal and distal tendon stumps repaired
end-to-end.
Proximal Z-lengthening of the
PTT may be needed to achieve direct repair. The
distal half of the anterior tibial tendon can be
detached proximally and left attached to its
insertion into the base of the first metatarsal
and utilized to reinforce the directly repaired
PTT.
Tendon transfer with FDL or
FHL
The PTT often has an irreparable
gap or is attenuated and scarred to the tendon
sheath. The posterior tibial muscle may function
poorly, even if the tendon can be directly
repaired. This has led several authors to
recommend tendon transfer to substitute for the
dysfunctional or irreparable PTT. Jahss reported
side-to-side tenodesis of the proximal and distal
stumps of the posterior tibial tendon to the
intact FDL tendon in five patients, reporting
short-term satisfactory results, although all
patients had residual heel valgus.
Transfer of the FDL tendon to
the distal PTT stump or directly into the
navicular tuberosity through a vertically oriented
tunnel has been advocated by several authors with
good short-term subjective results. The procedure
uniformly failed to correct the flatfoot deformity
but functioned well in relieving pain and
improving inversion strength.
Some authors have emphasized the
importance of spring ligament (calcaneonavicular
ligament) repair or reconstruction in conjunction
with FDL transfer. A retrospective study of spring
ligament repair/reconstruction and FDL transfer
demonstrated excellent functional results in 14
out of 18 patients, although arch correction on
radiographs was inconsistent.
Goldner et al reported using the
flexor hallucis longus (FHL) for transfer into the
distal PTT stump in two patients, one had a
previous laceration of the PTT and the other had a
chronic PTT tear. The younger patient had a full
and complete recovery, and the outcome in the
other patient was not reported.
Calcaneal osteotomy
Follow-up examination of
patients who have undergone FDL tenodesis or
transfer alone has not shown consistent correction
of deformity. Due to a concern of deteriorating
clinical results over time using soft-tissue
procedures alone, some surgeons added bony
procedures to the soft-tissue reconstruction. They
theorized that the restoration of arch height and
heel position might produce more durable and
improved clinical results. The ideal bony
procedure to treat acquired pes planovalgus
corrects the foot deformity, decreases strain on
the spring and deltoid ligaments, and protects the
soft-tissue reconstruction.
Gleich first described a medial
and inferior displacement osteotomy of the
posterior third of the calcaneus in 1893.
Koutsogiannis first described the medial
displacement calcaneal osteotomy as a treatment of
valgus hindfoot deformity. The addition of a
medial displacement osteotomy through the
posterior portion of the calcaneus moves the
valgus heel under the weightbearing axis of the
leg. The osteotomy also decreases the heel valgus
producing deforming force of the Achilles tendon
by shifting the Achilles insertion medially. In
vitro studies have shown that a 1-cm medializing
osteotomy of the calcaneal tuberosity decreases
strain on the spring ligament and deltoid
ligament. A 1-cm translational calcaneal osteotomy
actually moves the center of pressure in the ankle
joint 1.58 mm medially.
A retrospective study of 32
patients undergoing FDL transfer and calcaneal
osteotomy with an average of 20 months follow-up
showed 94% pain relief, improved function, and
significant improvement in radiographic arch
measurements. Sammarco and Hockenbury reported
satisfactory results in 19 patients undergoing FHL
transfer and medial displacement calcaneal
osteotomy. Despite the fact that the FHL is
stronger than the FDL, postoperative radiographs
did not show significant arch correction,
indicating that a medial soft-tissue procedure in
conjunction with calcaneal osteotomy may not
result in arch correction.
Lateral column lengthening
The Evans anterior calcaneal
lengthening osteotomy lengthens the lateral column
of the foot by inserting a 10- to 15-mm bone graft
10-15 mm proximal to the calcaneocuboid joint.
This lateral column-lengthening procedure has been
shown radiographically to improve forefoot
abduction and hindfoot valgus and to restore the
medial longitudinal arch. Cadaveric studies show
that lateral column lengthening protects the
calcaneonavicular (spring) ligament form overload
during weightbearing. A retrospective study of 19
patients undergoing an Evan's calcaneal osteotomy
in conjunction with PTT repair or shortening and
deltoid ligament repair or reconstruction reported
six excellent, 11 good, and two fair results.
Significant radiographic arch correction was noted
at 23-month follow-up.
A cadaver study of Evan's
calcaneal lateral column lengthening in normal
feet showed elevated calcaneocuboid joint
pressures following the procedure, raising
questions about potential long-term degenerative
arthritis of the calcaneocuboid joint following
the procedure. This concern has led to the
recommendation of lengthening the lateral column
through distraction arthrodesis of the
calcaneocuboid joint. However, another cadaver
study failed to confirm elevation of
calcaneocuboid joint pressure following calcaneal
Evans osteotomy in preexisting flatfeet and, in
some cases, actually showed lowering of
calcaneocuboid pressure following lateral column
lengthening.
A retrospective study of 41 feet
undergoing lateral column lengthening through
distraction arthrodesis of the calcaneocuboid
joint in conjunction with FDL transfer and
selective medial midfoot arthrodesis found
satisfactory outcomes in 85% of cases and a
uniform radiographic correction of flatfoot, but a
calcaneocuboid nonunion rate of 20% was found.
Note that this series included several patients
who also had fusions of the naviculocuneiform or
first metatarsocuneiform joints and that
distraction arthrodesis of the calcaneocuboid
joint was not the only bony procedure performed.
Thomas et al reported on 25
patients who underwent FDL transfer to the
navicular and lateral column lengthening using two
different methods. Postoperative American
Orthopedic Foot and Ankle Society (AOFAS) scores
were 87.9 for the osteotomy group and 80.9 for the
calcaneocuboid distraction arthrodesis group, but
the difference was not statistically significant.
Significant improvement in radiographic parameters
was seen in both groups. Complication rates were
high in both groups, with an especially high rate
of nonunion and delayed union in the
calcaneocuboid distraction group.
A combination of FDL transfer to
medial cuneiform, medial displacement calcaneal
osteotomy, and Evans lateral column lengthening
has produced good short-term results in a
retrospective study of 17 patients with stage 2
PTT dysfunction. Significant improvement in the
AOFAS hindfoot score was seen, and radiographs
showed significant improvement in arch
measurements at 17.5-month follow-up.
Fusion
The difficulty with achieving
consistent lasting correction of the flatfoot
deformity with soft-tissue procedures alone or in
conjunction with osteotomies has led some surgeons
to recommend fusion as a treatment of stage 2
deformity. Some surgeons feel that soft-tissue
procedures are less successful in patients who are
obese and that obesity is an indication for joint
fusion.
Kitaoka et al compared subtalar
arthrodesis versus FDL transfer in an in vitro
study of flatfooted specimens and found a more
consistent correction of deformity following
subtalar arthrodesis. A retrospective study of 21
feet treated with subtalar arthrodesis for PTT
dysfunction yielded good to excellent results in
16 out of 21 feet and significant correction of
flatfoot deformity based on radiographic
measurements. Stephens et al emphasize the need
for reducing the subtalar joint prior to fusion
and for differentiating a subtalar repositional
arthrodesis from a subtalar fusion in situ.
Another in vitro study compared
subtalar fusion alone, calcaneocuboid fusion
alone, talonavicular fusion alone, double (talonavicular
and calcaneocuboid) arthrodesis, and triple
arthrodesis in their abilities to correct an
experimentally corrected flatfoot deformity. The
study found that talonavicular or double
arthrodesis resulted in better correction of
flatfoot deformity than did subtalar fusion alone.
A retrospective study of 29 patients with PTT
dysfunction treated with isolated talonavicular
fusion found good to excellent results in 86% of
patients at an average follow-up of 26 months.
Combination treatments
Johnson et al utilized subtalar
fusion, FDL transfer, and spring ligament repair
in 17 feet with stage 2 dysfunction. At an average
follow-up of 27 months, they reported excellent
radiographic correction of pes planus deformity
and improvement in AOFAS hindfoot score.
Chi et al reported on 65 feet
that underwent FDL transfer with lateral column
lengthening and/or medial column fusion. Lateral
column fusion was performed for calcaneovalgus
deformity with a flat calcaneal pitch angle. If
the naviculocuneiform or first metatarsocuneiform
joint showed sag on lateral radiographs, they also
were fused. At 1- to 4-year follow-up, 88% of the
feet that underwent lateral column lengthening,
80% of the feet that had medial column
stabilization, and 88% that had medial and lateral
procedures had decreased pain or were pain-free.
Significant radiographic correction of the pes
planus deformity was seen in all groups. The
authors concluded that fusion of these unessential
joints effectively corrected deformity and
relieved pain.
Surgical treatment of stage 3
dysfunction
Surgical treatment of stage 3
posterior tibial tendon dysfunction requires
realignment and arthrodesis of rigidly malaligned
joints. The principle of fusing the fewest number
of joints possible should be followed. Over time,
the subtalar joint becomes fixed in valgus, and a
subtalar arthrodesis is indicated to realign the
hindfoot. If the forefoot is fixed in varus at the
transverse tarsal (Chopart) joint or degenerative
changes are present in the talonavicular and
calcaneocuboid joints, fusion of these joints
should be added. Stage 3 posterior tibial tendon
dysfunction with fixed forefoot varus is treated
with triple arthrodesis.
Surgical treatment of stage 4
dysfunction
The valgus ankle in stage 4
dysfunction develops due to deltoid ligament
instability. The deltoid ligament is difficult to
reconstruct with a tendon transfer. Arthritic
valgus ankle deformities secondary to deltoid
ligament insufficiency have not been successfully
treated with a total ankle arthroplasty due to the
inability to achieve ligamentous balance.
Treatment of a fixed subtalar deformity and
degenerative ankle valgus requires
tibiotalocalcaneal fusion. If fixed forefoot varus
is also present, a pantalar fusion may be
necessary to adequately realign the foot. Either
tibiotalocalcaneal or pantalar fusion results in a
very stiff foot, which results in an altered gait.
Shoe modifications and bracing are often required
after surgery.
Table 2. Summary of Surgical
Treatment
| Stage |
Surgical Treatment |
| Stage 1 |
Tenosynovectomy, tendon
debridement, tendon repair of partial tears |
| Stage 2* |
PTT repair
FDL or FHL transfer alone
FDL or FHL transfer + calcaneal osteotomy
FDL transfer + lateral column lengthening
FDL transfer + lateral column
lengthening+medial column fusion
FDL transfer+lateral column
lengthening+calcaneal osteotomy
Subtalar fusion
Talonavicular fusion
|
| Stage 3 |
Subtalar fusion
Triple arthrodesis |
| Stage 4 |
Tibiotalocalcaneal fusion
Pantalar fusion |
* Add Achilles tendon
lengthening or gastrocnemius recession in cases of
equinus contracture
Preoperative details:
The stage of the
disease, the overall medical condition of the
patient, and the patient's expectations determine
the recommended treatment. If the patient has low
physical demands or has serious underlying medical
problems, he/she should be treated nonoperatively.
Patients should be advised about the prolonged
length of recovery following surgical
reconstruction of the foot. Generally, 6 weeks of
nonweightbearing is required for soft-tissue
procedures and osteotomies, and up to 3 months of
nonweightbearing is required for fusions. Swelling
of the foot should be expected for 4-10 months
after surgery. Finally, although most surgical
procedures report a high incidence of
good-to-excellent results postoperatively, many
patients continue to have some foot discomfort
with prolonged standing or walking.
Intraoperative details:
FHL transfer
An 8-cm incision is made along
the course of the posterior tibial tendon from a
point just proximal and posterior to the medial
malleolus to the navicular tuberosity. The
posterior tibial tendon sheath is opened and a
tenosynovectomy is performed. Partial tears of the
tendon are repaired with 2-0 nonabsorbable Dacron
sutures. If the tendon is attenuated and
irreparable, it is excised, leaving a 1-cm stump
attached to the navicular tuberosity. If the
spring ligament is torn or attenuated, it is
repaired and imbricated with 2-0 nonabsorbable
sutures. The FDL tendon is identified in its
sheath just deep to the PTT sheath. The FHL tendon
is identified deep to the sustentaculum tali. The
FHL tendon is sutured to the FDL tendon distally
with 2-0 nonabsorbable sutures and then divided
proximal to the anastomosis.
A suture anchor is placed in the
navicular tuberosity, and the transferred FHL
tendon is sutured to the navicular and to the
distal PTT stump with number 2 nonabsorbable
sutures. Tension on the FHL tendon is adjusted
with the foot in inversion and plantarflexion. The
tendon sheath, subcutaneous tissue, and skin are
closed in layers. Percutaneous triple-cut Achilles
tendon-lengthening or gastrocnemius recession is
performed if the foot cannot be easily dorsiflexed
past neutral.
Following surgery, the foot is
placed in a posterior splint in a position of
equinus and inversion. A short-leg
nonweightbearing cast is applied at 3 days
postoperatively, maintaining the position of
equinus and inversion, and is worn for 4 weeks.
The foot then is placed in a short-leg walking
cast in a neutral position, which is worn for an
additional 2 weeks. A Cam walker boot is worn
beginning 6 weeks postoperatively and is removed
for range of motion and strengthening exercise.
Immobilization is discontinued 10 weeks
postoperatively.
FDL tendon transfer
A similar approach is used for
the FDL tendon transfer. In this case, the distal
FDL is sutured into the FHL, and the FDL is
released just proximal to the suture to give
adequate length to the tendon. A vertical hole
then is drilled into the navicular bone. The
surgeon should be careful to leave an adequate
bridge of bone in place medially. The plantar hole
is rounded smooth proximally to take any sharp
edge away that may damage the tendon. With the aid
of a suture passer, the FDL tendon is routed from
plantar to dorsal and sutured to itself (if enough
tendon length is available) and to the surrounding
tissue. The foot is held in an inverted position
during this maneuver to place appropriate tension
on the FDL tendon. Closure and postoperative care
are similar to those for FHL transfer.
Calcaneal osteotomy
Calcaneal osteotomy is used in
conjunction with FDL or FHL transfer. The
calcaneal osteotomy is performed prior to the
tendon transfer. A 5-cm oblique incision is made
along the lateral heel from posterosuperior to
anteroinferior. The incision is made posterior to
the peroneal tendon sheath and sural nerve. Sharp
dissection is utilized to proceed directly down to
bone. Skin flaps are kept thick. The lateral wall
of the calcaneus is exposed subperiosteally using
a Key elevator. Small Hohmann retractors are
placed over the superior aspect of the calcaneus
anterior to the Achilles tendon and at the plantar
aspect of the calcaneus anterior to the plantar
fascial attachment.
A straight wide power osteotome
(Micro-Aire, Inc) or sagittal saw is used to make
a cut across the calcaneus in line with the
incision at a 45-degree angle to the plantar
surface of the foot and perpendicular to the
surface of the calcaneus. C-arm fluoroscopy is
used to document proper osteotomy position prior
to making the bone cut. The medial aspect of the
heel is palpated to gauge the depth of the
osteotomy and to avoid overpenetration of the
osteotome, which could cause injury to the tibial
nerve and vessels. The depth of the osteotome cut
also can be judged with a freer elevator during
completion of the cut. After completion of the
osteotomy, the medial soft tissues are spread by
inserting a large Key elevator into the osteotomy
site and levering the calcaneal tuberosity
downward. A laminar spreader also can be placed
into the osteotomy site and used to spread the
medial soft tissues.
The tuberosity should be easily
translated medially 1 cm if the medial soft
tissues are adequately mobilized. It is important
to ensure that the plantar surface of the
osteotomy has been adequately mobilized.
Otherwise, the posterior calcaneal fragment will
rotate internally rather than slide medially. The
calcaneal tuberosity then is translated 1 cm
medially, while avoiding superior translation of
the fragment. A surgical assistant then holds the
osteotomy in a corrected position while it is
fixated with two 4.0-mm diameter partially
threaded cancellous screws placed perpendicular to
the osteotomy cut. Typically, no washers are used.
Avoid placement of the screws
into the subtalar joint and keep the screw heads
off of the weightbearing surface of the heel.
Screws are placed in a parallel fashion. Because
the tuberosity has been shifted medially, the
screws should be aimed slightly laterally in order
to hit the main calcaneal body or the screw(s) may
miss the anterior calcaneus. Screw position is
documented with intraoperative fluoroscopy.
The wound is closed in layers.
Postoperative care is the same as for FDL
transfer, except weZngthening
by distraction arthrodesis of calcaneocuboid joint
This procedure is also performed
in conjunction with FDL or FHL transfer. A 5-cm
dorsolateral incision is made over the
calcaneocuboid joint. The sural nerve and peroneal
tendons are retracted plantarly. The joint is
exposed, and the articular cartilage is removed
with osteotomes and curettes. The joint then is
distracted using a smooth laminar spreader. An
alternative technique is to use a small joint
external fixator (EBI) to distract the lateral
column, placing pins in the cuboid and calcaneus.
Correction of the medial longitudinal arch and
correction of heel valgus to neutral or slight
valgus serve as the endpoint for distraction. The
forefoot also should be rotated into neutral
position prior to graft insertion.
A trapezoidal tricortical iliac
crest graft then is fashioned to fit the
distracted joint. The bone graft should be wider
both dorsally and laterally, and tapering towards
the plantar and medial aspects, respectively. A
graft width of 8-12 mm usually suffices. A
cervical plate placed laterally with 2 screws in
the calcaneus and 2 screws in the cuboid is used
for fixation. The remainder of the calcaneocuboid
joint is filled with cancellous graft. The
postoperative course is the same as for the
calcaneal osteotomy, except weightbearing is
delayed until fusion is confirmed radiographically.
