Keywords
tarsal tunnel syndrome - posterior tibial nerve - conservative treatment - surgical
treatment.
Palavras-chave
síndrome do túnel do tarso - nervo tibial posterior - tratamento conservador - tratamento
cirúrgico.
Introduction
The tarsal tunnel syndrome (TTS) was implemented in 1962 by Charles Keck, who published
the first clinical cases on the topic and, in that same year, Lam published an article
detailing the syndrome.[1]
[2]
[3] The compression of the tibial nerve and its branches has a close anatomical relationship
with its adjacent structures: bone, muscle, and vascular structures ([Image 1]).
Image 1
Tibial nerve at the level of the medial malleolus in the right lower limb. Note that the flexor retinaculum was sectioned, exposing the division of the tibial
nerve into the medial and lateral plantar nerve. The posterior tibial vein was isolated
through the blue strip, and the posterior tibial artery through the red strip. Image
kindly provided by Magalhães MJS. Neuroanataomia dos nervos periféricos. 1st edition. Brazil. Independently published. 2021. 1-Tibial nerve. 2-Posterior tibial
vein. 3-Posterior tibial artery. 4-Medial plantar nerve. 5-Lateral plantar nerve.
The flexor retinaculum extends between the medial malleolus and the medial side of
the calcaneus supporting the tendons of the posterior tibial muscles, the long flexor
of the fingers, the long flexor of the hallux, and the vascular structures—posterior
tibial artery and vein. The bony floor and the deep fascia of the abductor hallucis
muscle form the tunnel of the distal tarsus.[4]
Symptoms include pain and paresthesia in the posterior region of the foot that can
radiate to the plantar region. Initially, pain complaints tend to occur after strenuous
physical activity, prolonged standing periods, and use of certain types of shoes,
but they tend to improve with rest.[3]
[5] The clinical diagnosis can be reinforced by the positivity of the Tinel signal and
due to the presence of changes in nerve conduction at electroneuromyography (ENMG).[3]
[4]
[5]
Many causes can contribute to the onset of the disease: fractures or dislocations
involving the talus, calcaneus or medial malleolus, ganglion cysts, tumors, hypothyroidism,
and inflammatory causes, such as rheumatoid arthritis and diabetes mellitus.[3]
[5]
[6]
[7]
[8]
[9]
[10]
Tarsal tunnel syndrome is the fifth most discussed compressive disease in the literature;
however, there are still controversies in relation to treatment since opinions are
greater than the evidence when it comes to choosing surgical treatment or maintaining
conservative measures and what to do in cases of recurrence. Therefore, the present
review aims to evaluate the efficacy of surgical treatment, compared with conservative
treatment, in reducing the symptoms of TTS.
Methods
Guiding question
Is surgical treatment more effective in remission of pain and hypoesthesia in TTS
compared to conservative treatment? ([Table 1])
Table 1
Construction of the guiding question
|
P
|
Population
|
Tarsal tunnel syndrome patients
|
|
I
|
Intervention
|
Surgical treatment
|
|
C
|
Control
|
Conservative treatment
|
|
O
|
Outcome
|
Remission of pain and hypoesthesia
|
Eligibility criteria and variables
Only clinical studies with and without randomization were selected for the construction
of the systematic review. We also opted for studies with a minimum of 3 months of
follow-up after intervention and that used the following diagnostic criteria: clinical
symptoms, positive Tinel signal, and/or altered electrodiagnostic study. All surgical
techniques were included, and all conservative treatments were considered. Two researchers
independently searched the databases, and another was the tiebreaker.
The variables studied are the complementary exam used for diagnosis, treatment modality,
number of patients enrolled, symptoms presented, outcome after treatment, and complications.
Studies that did not address the treatment of patients were not considered, neither
were those that included patients with diabetic polyneuropathy, leprosy, tendinopathies,
and painful syndromes involving other nerves of the foot. This strategy was used to
reduce confusion bias.
Reasoning
After a literature search in the Cochrane Library, PubMed and SciElo databases, no
previous published studies were found that definitively answered the question, which
corroborates the relevance of the study in question.
Source of data and search
The databases used were PubMed, Lilacs, Cochrane Library, and Physiotherapy Evidence
Database (PEDro), with the date of the last access being July 21, 2020. The bibliography
of the articles found was also analyzed in search of other relevant articles, with
the last search being on September 4, 2020. The date of publication and the language
of the study were not considered as criteria for the selection of articles. ([Table 2])
Table 2
Keywords used in the researched databases with last access on July 21, 2020
|
Data base
|
Keywords
|
Number of articles found
|
|
PubMed
|
syndrome, tarsal tunnel OR tibial
neuropathy OR posterior
tibial
nerve
neuralgia AND tarsal, tunnel
syndrome AND surgical
interventions AND surgical
treatment AND conservative
treatment.
|
8
|
|
Lilacs
|
tarsal
tunnel
syndrome [Subject descriptor] or síndrome do tunel do tarso [Subject descriptor] or síndrome del túnel tarsal [Subject descriptor]
|
25
|
|
PEDro (Physiotherapy Evidence Database)
|
|
PEDro: 2
|
|
Cochrane Library
|
Tarsal
tunnel
syndrome
|
Cochrane: 17
|
Data collection process
After identifying the articles available in the databases, the title and abstract
were initially read, thus resulting in a sample of 52 articles. Then, the Mendeley
desktop reference manager was used to assist in the selection of studies. From the
complete reading of the texts, 11 articles were chosen to compose the research. ([Figure 1])
Fig. 1 Data collection
Risk of bias
After analyzing the selected articles, some significant differences were found. Among
them, we can mention the time interval between diagnosis and the beginning of treatment,
the etiology of nerve compression and the evaluation of the therapeutic response.
It is known that such situations can generate bias when comparing the effectiveness
of the treatment.
There was a bias both in the choice of articles (different levels of evidence) as
well as in the size and characteristics (gender, age, comorbidities) of the studied
samples. In view of the management proposed in the different studies, there was no
standardization between the types of conservative treatment and surgical techniques
used, which may compromise the reliability of this systematic review.
Results
Description of the studies
Two case reports were found (SETTANNI, 1994; CHON, 2014). Settanni et al. (1994) evaluated
7 female patients, with clinical and ENMG evidence of TTS, who had previously undergone
some type of conservative treatment. The seven patients underwent open surgery, two
of which were bilateral. There was improvement in pain and hypoesthesia in three,
improvement in pain and partial recovery of hypoesthesia in three, and one loss to
follow-up. In the study by Chon et al. (1994), only 2 patients (one woman and one
man) were evaluated, with the presence of a positive Tinel signal and an altered ENMG.
Only one of them had a history of open surgery for decompression of the tibial nerve,
with no improvement in pain. After the pulsed radiofrequency, the patients were followed
for a period of 8 to 12 months, with good response (control of pain and reduction
of hypoesthesia).[9]
[11]
In addition to these, 9 clinical trials were analyzed (TAKAKURA et al., 1991; PFEIFFER
et al.,1994; BABA et al., 1997; KOHNO et al., 2000; SAMMARCO et al., 2003; FLORES,
2005; JEROSCH et al., 2006; KRISHAN et al., 2006; KAVALAK et al., 2011).[5]
[6]
[7]
[8]
[10]
[12]
[13]
[14]
[15]
In the study of Kavalak et al. (2011), 28 patients were randomly divided into 2 groups.
In the control group, the patients underwent a 6-week physical therapy program at
home, while in the other, patients received, in addition to the physical therapy program,
nerve mobilization exercises. Before starting the treatment, the patients were evaluated
for muscle strength and range of motion. All of them had clinical manifestations compatible
with TTS, and the Tinel signal was present in most of them. At the end of the 6 months,
both groups were reevaluated, and an increase in muscle strength and reduced pain
was found in both groups, but improvement in sensory parameters was reported only
in the test group.[12]
Another study by Krishan et al. (2006) involved 20 patients, 11 with ulnar sulcus
syndrome, 8 with TTS, and 1 with meralgia paresthesia. All patients underwent surgery
with an integrated endoscopic technique. Of the eight patients with TTS, three were
female and five were male. The presence of classic symptoms of nerve compression,
failure of conservative treatment, altered ENMG, and non-violated anatomical region
were used as selection criteria. The follow-up time varied between 3 and 28 months,
and the results found were: absence of pain and paresthesia in five feet, and improvement
of pain and reduction of paresthesia in three.[7]
The study conducted by Jerosch et al. (2006) addressed 77 surgical decompressions
performed on 75 patients (54 women and 21 men), with the mandatory criterion of a
minimum period of 6 months of conservative treatment. The results were evaluated according
to pain at rest, pain during walking, and weakness, and, according to the modified
American Orthopedic Foot and Ankle Society (AOFAS) score, there was a reduction in
pain at rest in 53 patients, and improvement in subjective muscle weakness in 6. Only
three feet had superficial infection of the postoperative wound.[5]
The study conducted by Flores (2005) consisted of a retrospective analysis of nine
patients diagnosed with idiopathic TTS, in which open surgery was performed with the
aid of a surgical magnifying glass. The nine feet showed improvement in pain and paresthesia;
however, five had postoperative wound infection, and six had wound dehiscence.[8]
Kohno et al. (2000) published the surgical results of complete resection of the flexor
retinaculum associated with the insertion of a fat graft between the dissected vessels
and the nerve. This procedure was performed on 12 feet of 9 patients diagnosed with
idiopathic TTS. Most patients had a good response in the first 3 months of postoperative
follow-up.[6]
In another study by Sammarco et al. (2003), 72 feet underwent open surgery for decompression
of the tibial nerve. The diagnosis was made in the presence of clinical signs and
symptoms and altered ENMG; 31 patients had a history of foot trauma. Postsurgical
follow-up lasted an average of 58 months. The Maryland Foot Score (MFS) was used before
and after the operation, with the average score obtained before the procedure being
64/100, and after 80/100. The AOFAS score was used only in the postoperative period,
and the average was also 80/100. Patients presenting with symptoms for less than 1
year had the highest score on both scores.[10]
Baba et al. (1997) described 34 patients with TTS, with the condition being bilateral
in 3 cases. Of these, 9 were male, and 25 were female, with an average age of 41 years.
Open surgery with excision of compressive structures was performed. There was no report
of previous conservative treatment. The average follow-up period was 3.8 years, and
the multivariate analysis showed that the results are influenced by the presence of
fibrosis around the nerve, severity of the preoperative condition, history of ankle
sprain and heavy work.[13]
Takakura et al. (1991) linked the causes of TTS to the response to treatment, with
the best results in patients in whom some structure was causing compression, such
as coalition and tumor.[14] These authors described 45 patients with TTS. Of these, 21 were male, and 24 were
female. All patients underwent surgery with follow-up time varying between 1 and 13
years. Good pain control was obtained in patients with diagnosis of tarsal coalition,
tumor, and ganglion. Fair pain control was observed in patients with idiopathic TTS
and previous trauma.
Finally, the work of Pfeiffer et al. (1994) reviewed the clinical results of 30 patients
(32 feet) who underwent surgical decompression of the posterior tibial nerve in the
period between 1982 and 1990. The average duration of the segment was 31 months, and
the results obtained were: 44% of the feet benefited from the surgery with good or
excellent results; 38% had unsatisfactory results, with no long-term pain relief;
pain reduced by 19%, but patients still complained about paresthesia; and 13% of the
feet had complications in the surgical wound. Based on these results, the authors
concluded that unless there is a known structure causing compression of the tibial
nerve, surgery should be recommended with caution.[15]
We identified a rate of good or excellent pain control of 68% (n = 204) for open surgery
(n = 299), 100% (n = 8) for endoscopic surgery (n = 8), and 7% (n = 2) for conservative
treatment (n = 28).[5]
[6]
[7]
[8]
[9]
[10]
[12]
[13]
[14]
[15]
Discussion
The research considered 11 articles, 2 case reports and 9 clinical trials, with a
total of 309 participants (337 feet evaluated). As for the etiology of the syndrome,
it can be primary (idiopathic) or secondary to a series of diseases in the hindfoot
region. The most common causes identified were presence of ganglia, bone prominence
causing a talocalcaneal collision, trauma, varicose, and idiopathic veins.[16]
The clinical manifestations may differ according to the disease that causes the compression;
however, most patients presented the classic picture of pain in the medial plantar
region, and paresthesia that can radiate to the fingers or to the calf (Valleix phenomenon).
Pain tends to worsen at night.[16]
[17]
The diagnosis was based on clinical history and physical examination, the vast majority
of patients have a positive Tinel sign, some have a positive tibial nerve compression
maneuver, and others report improvement in pain and paresthesia with posterior tibial
nerve block with 3 ml of 1% lidocaine.[16]
As for complementary exams, the presence of latency in sensory nerve conduction is
the most common finding in electrodiagnostic tests, because, in the initial stages,
the damage is mainly sensory, due to the greater susceptibility of the sensitive fibers
to injury. Kohno et al. (2000) performed the measurement of the sensory nerve conduction
VELOCITY (NCV) in 5 of his patients, and only 2 presented slow VCS, less than 35 m/s.
No study has been able to correlate the results of electrodiagnostic tests with the
results obtained after the surgical procedure, so these tests should only be used
as an aid to diagnosis, and the presence of a normal test does not rule out the presence
of TTS.[6]
[17]
Imaging exams play an important role for the identification of secondary etiologies
of TTS. A simple foot X-ray can identify fractures and bony prominences in the vicinity
of the tarsal tunnel. Magnetic resonance imaging is the most suitable for assessing
the structures close to the flexor reticulum and to identify those that may be causing
the compression of the posterior tibial nerve or one of its branches. In patients
complaining of low back pain associated with pain in the foot radiating to the calf,
a magnetic resonance imaging (MRI) of the lumbosacral spine should be requested to
perform a differential diagnosis with S1 radiculopathy.[16]
The time of disease evolution was quite variable between the articles, some authors
mentioned as an eligibility criterion that the patient must have undergone at least
a few months of conservative treatment before being submitted to the surgical procedure.[5]
[6]
Regarding surgical techniques, the release of the posterior tibial nerve via endoscopy
had a favorable outcome in relation to the symptoms of pain and hypoesthesia, with
no reports of infection of the operative site.[7]
[Table 3]
Table 3
Summary of studies about treatment of tarsal tunnel syndrome selected for systematic
review
|
Authors
|
Article
|
Patients
|
Number of limbs
|
Age
|
Gender
|
Comorbidities
|
Treatment
|
Time of follow up
|
Outcome
|
|
Jerosch J et al.
|
Results of surgical treatment of tarsal tunnel syndrome
|
75
|
77
|
17–77
|
F: 54
M: 21
|
−
|
Open surgery
|
6–100 months and mean value = 39 months
|
- Good pain control (n = 53)
-Improvement of paresia (n = 6)
-Incision infection (n = 3)
|
|
Kohno M et al.
|
Neurovascular decompression for idiopathic tarsal tunnel syndrome: technical note
|
9
|
12
|
52–78
|
F: 6 M:3
|
−
|
Open surgery
|
9–61 months and mean value = 26.8 months
|
- No pain control (n = 2)
- Good pain control (n = 10)
- Incision infection (n = 0)
|
|
Krishnan GK et al.
|
A novel endoscopic technique in treating single nerve entrapment syndromes with special
attention to ulnar nerve transposition and Tarsal Tunnel release: clinical application
|
8
|
8
|
35–64
|
F: 3 M: 5
|
Diabetes mellitus (n = 1)
|
Endoscopy surgery
|
3–28 months and mean value = 10.1 months.
|
- Excellent pain control (n = 5)
- Good pain control (n = 3)
- Partial pain control (n = 0)
- No pain control (n = 0)
- Incision infection (n = 0)
|
|
Settanni FA et al.
|
Management of tarsal tunnel syndrome. Report of seven cases
|
7
|
10
|
43–72
|
F: 7 M: 0
|
-Previous foot surgery (n = 12)
-Previous Tarsal decompressive surgery (n = 6)
-Rheumatoid arthritis (n = 3_
- Neuroma plantar medial (n = 1)
|
Open surgery
|
3 months–3 years
|
- Excellent pain control (n = 3)
- Good pain control (n = 3)
- No information (n = 1)
|
|
Pfeiffer WH, Crachiolo A
|
Clinical results after tarsal tunnel decompression
|
30
|
32
|
13–72
|
F: 24 M: 6
|
−
|
Open surgery
|
24–118 months and mean value = 31 months
|
-Excellent pain control (n = 5)
- Good pain control (n = 9)
- Partial pain control (n = 5)
- No pain control (n = 10)
- Incision infection (n = 1)
|
|
Flores LP
|
Outcome of surgical treatment of idiopathic posterior tarsal tunnel syndrome
|
9
|
9
|
33–52
|
F: 7 M: 2
|
−
|
Open surgery
|
4–24 months
|
- Good pain control (n = 9)
- Incision infection (n = 5)
- Incision dehiscence: (n = 6)
|
|
Chon JY et al.
|
Pulsed radiofrequency under ultrasound guidance for the tarsaltunnel syndrome: two
case reports
|
2
|
2
|
56–67
|
F:1 M:1
|
-Foot trauma (n = 1)
|
Pulsed radiofrequency
|
8–12 months
|
- Good pain control (n = 2)
|
|
Kavlak Y et al.
|
Effects of nerve mobilization exercise as an adjunct to the conservative treatment
for patients with Tarsal Tunnel syndrome
|
28
|
28
|
40–57
|
F: 4 M: 12
|
- Hypertension (n = 7)
- Diabetes mellitus (n = 3)
- Ateriosclerosis (n = 1)
- Foot trauma (n = 14)
|
Mobilization exercise as an adjunct to the conservative treatment
|
3 months
|
- Good control pain (n = 2)
|
|
Baba H et al.
|
The tarsal tunnel syndrome: evaluation of surgical results using multivariate analysis
|
34
|
37
|
14–73
|
F: 25 M:9
|
-Ankle arthritis (n = 33)
- Foot trauma (n = 31)
-Diabetes mellitus (n = 7)
- Low back pain (n = 37)
|
Open surgery
|
1-7 years.
Mean value = 3.8 years
|
-Excellent pain control n = 26 * -Good pain control n = 6 *
-No pain control (n = 5) *
* number of limbs
|
|
Sammarco GJ et al.
|
Outcome of surgical treatment of tarsal tunnel syndrome
|
62
|
72
|
17–80
|
F:44 M: 18
|
- Foot trauma (n = 5)
- Tumor (n = 3)
|
Open surgery
|
12–185 months and mean value = 58 months
|
-Excellent pain control (n = 21)* -Good pain control (n = 17)*
-Partial control (n = 19)*
- No pain control (n = 16)*
* number of limbs
|
|
Takakura Y et al.
|
Tarsal tunnel syndrome. Causes and results of operative treatment
|
45
|
50
|
10–71
|
F:24 M:21
|
- Ganglia (n = 18),
- Bony prominence from talocalcaneal coalition (n = 15)
- Tumor (n = 3)
- Trauma (n = 5)
|
Open surgery
|
1-13 years and mean value= 4 years and 9 months
|
- Good pain control in tarsal coalition, tumor, and ganglion groups. Fair pain control
in idiopathic and trauma group.
|
In open surgeries, there is no consensus on the use of tourniquets during the procedure.
Although the tourniquet is effective in reducing intraoperative bleeding, some authors
argue that it alters neurovascular conditions, making it impossible for the surgeon
to identify possible arteries or veins that may be responsible for compression. As
for sedation, some studies have recommended the use of local anesthesia associated
with mild sedation, so that the patient is able to alert the professional about pain
irradiation at the time of surgery, which can assist in the correct identification
of the affected nervous branch. According to Kohno et al. (2000), if during the surgical
procedure no structure is found that may be causing the compression, a fat graft should
be placed between the nerve and the vessels to prevent them from sticking later.[6]
[8]
[Table 3]
The follow-up period for patients varied between 3 months and 13 years. The tools
used to assess patients' improvement after therapeutic intervention have not been
standardized. One of the articles used more than one method,[7] while others did not report the method used.[2]
[9]
[Table 3]
Among the strategies applied are validated scales (visual analogue scale, Maryland
foot score, American Orthopedic Foot and Ankle Society - Ankle Kind foot score)[5]
[10]
[11]
[12]; own scales[13]
[14]; clinical evaluation (Tinel sign), and complementary exams (computed tomography
[CT], MRI, ENMG).[6]
[15] Some studies have suggested a follow-up of at least 12 months, as the patient may
experience an improvement in pain and paresthesia initially, with recurrence a few
months later.[5]
[15]
In the group of operated patients, the ones who benefited most from the procedure
were those who had a structure such as ganglion, cysts, or varicosities causing compression;
in other patients, the results were poor even with the authors reporting careful decompression
of the nerve. Patients who had previously undergone some previous foot surgery, mainly
involving the tibial nerve had a poor result, possibly due to the presence of fibrosis
around the nerve ([Table 3]).
The most cited complications were postsurgical wound infection, wound dehiscence,
and calcaneus hypoesthesia. [Table 3] Flores draws attention to the varied origin of the medial calcaneus branch, which
may emerge from the tibial nerve or from one of its branches,. According to this author,
during surgery, care must be taken to avoid injury to the calcaneus branch, which
can result in hypoesthesia of the heel or formation of heel.[8]
The study of Chon et al. (1994) showed the effectiveness of ultrasound-guided pulsed
radiofrequency, despite the small number of patients analyzed. It has shown promise,
especially for patients who have not improved after surgical decompression, and also
for those who the surgery has not been beneficial to (trauma, idiopathic origin, presence
of plantar fasciitis, systemic inflammatory disease). However, more studies are needed.[11]
Conclusion
The most common causes of TTS identified were presence of ganglia, bone prominence
causing a talocalcaneal collision, trauma, and varicose and idiopathic veins. The
main symptoms were pain in the medial plantar region and paresthesia that can radiate
to the fingers or to the calf. Most patients have a positive Tinel sign in their physical
examination. The electrodiagnostic test usually shows the presence of latency in sensory
nerve conduction. There is no consensus that a longer time between diagnosis and surgical
treatment leads to worse prognosis. In the group of operated patients, the ones who
benefited most from the procedure were those who had a structure such as ganglion,
cysts, or varicosities causing compression. The tools used to assess patients' improvement
after therapeutic intervention have not been standardized. The most cited surgical
complications were: postsurgical wound infection, wound dehiscence, and calcaneus
hypoesthesia. Regarding surgical techniques, the release of the posterior tibial nerve
via endoscopy had a favorable outcome in relation to the symptoms of pain and hypoesthesia,
with no reports of infection of the operative site. We identified a rate of good or
excellent pain control of 68% (n = 204) for open surgery (n = 299), 100% (n = 8) for
endoscopic surgery (n = 8) and 7% (n = 2) for conservative treatment (n = 28).
