Common Peroneal Nerve and Tarsal Tunnel Release Surgery in an Adolescent Male with Hunter Syndrome: Illustrative Case

BACKGROUND

Children with Hunter syndrome have a high prevalence of nerve compression syndromes given the buildup of glycosaminoglycans in the tendon sheaths and soft tissue structures. These are often comorbid with orthopedic conditions given joint and tendon contractures due to the same pathology. While carpal tunnel syndrome and surgical treatment has been well-reported in this population, the literature on lower extremity nerve compression syndromes and their treatment in Hunter syndrome is sparse.

OBSERVATIONS

We report the case of a 13-year-old male with a history of Hunter syndrome who presented with toe-walking and tenderness over the peroneal and tarsal tunnel areas. He underwent bilateral common peroneal nerve and tarsal tunnel releases, with findings of severe nerve compression and hypertrophied soft tissue structures demonstrating fibromuscular scarring on pathology. Post-operatively, the patient's family reported subjective improvement in lower extremity mobility and plantar flexion.

LESSONS

In this case, peroneal and tarsal nerve compression were diagnosed clinically and treated effectively with surgical release and postoperative ankle casting. Given the wide differential of common comorbid orthopedic conditions in Hunter syndrome and the lack of validated electrodiagnostic normative values in this population, the history and physical examination and consideration of nerve compression syndromes are tantamount for successful workup and treatment of gait abnormalities in the child with Hunter syndrome.

Ganglia-Induced Tarsal Tunnel Syndrome

BACKGROUND

Tarsal tunnel syndrome (TTS) is a common entrapment neuropathy that is sometimes elicited by ganglia in the tarsal tunnel.

METHODS

Between August 2020 and July 2022, we operated on 117 sides with TTS. This retrospective study examined data from 8 consecutive patients (8 sides: 5 men, 3 women; average age 67.8 years) with an extraneural ganglion in the tarsal tunnel. We investigated the clinical characteristics and surgical outcomes for these patients.

RESULTS

The mass was palpable through the skin in 1 patient, detected intraoperatively in 1 patient, and visualized on MRI scanning in the other 6 patients. Symptoms involved the medial plantar nerve area (n = 5), lateral plantar nerve area (n = 1), and medial and lateral plantar nerve areas (n = 2). The interval between symptom onset and surgery ranged from 4 to 168 months. Adhesion between large (≥20 mm) ganglia and surrounding tissue and nerves was observed intraoperatively in 4 patients. Of the 8 patients, 7 underwent total ganglion resection. There were no surgery-related complications. On their last postoperative visit, 3 patients with a duration of symptoms not exceeding 10 months reported favorable outcomes.

CONCLUSIONS

Because ganglia eliciting TTS are often undetectable by skin palpation, imaging studies may be necessary. Early surgical intervention appears to yield favorable outcomes.

Botulinum Toxin Injection for the Treatment of Compression of Lateral Plantar Nerve by Flexor Digitorum Accessorius Longus

ABSTRACT

The flexor digitorum accessorius longus is an anomalous muscle with a reported prevalence of 1.6%-12.2% in cadaveric studies. Flexor digitorum accessorius longus courses through the tarsal tunnel and has been reported as an etiology of tarsal tunnel syndrome in previous case reports. The flexor digitorum accessorius longus is intimately related to the neurovascular bundle and may impinge on the lateral plantar nerves. However, very few cases of lateral plantar nerve compression by the flexor digitorum accessorius longus have been reported. Herein, we report a case of lateral plantar nerve compression caused by the flexor digitorum accessorius longus muscle in a 51-year-old man who complained of insidious pain at the lateral sole and hypoesthesia at the left third-fifth toe and lateral sole, and the pain improved after treatment of botulinum toxin injection into the flexor digitorum accessorius longus muscle.

Prevalence of Obesity in High Tarsal Tunnel Syndrome: A Cross-Sectional Study

BACKGROUND

Tarsal tunnel syndrome (TTS) occurs when an individual suffers from tibial nerve compression at the tarsal tunnel. Symptoms of TTS may include pain, burning, or tingling on the bottom of the foot and into the toes. Tarsal tunnel syndrome can be divided into distal and proximal TTS. Furthermore, a high tarsal tunnel syndrome (HTTS) has also been described as a fascial entrapment proximal to the laciniate ligament at the level of the high ankle. Multiple risk factors, including obesity, have been said to be associated with TTS. This study aimed to determine the frequency of obesity in the form of body mass index (BMI) with HTTS.

METHODS

A cross-sectional descriptive study using a nonprobability sampling method retrospectively surveyed the BMI of 73 patients whose clinical presentation suggested HTTS or TTS, and in which electrodiagnostic testing found HTTS. The age of the patients ranged from 25 to 90 years (mean, 56.4 years). Thirty-five patients were men and 38 patients were women.

RESULTS

Based on BMI, nine patients with HTTS had normal weight (12.9%), 17 patients were overweight (23.3%), and the remaining 47 patients were obese (64.3%).

CONCLUSIONS

The frequency of obesity in the form of BMI was 64.3% in patients with HTTS, which is a significantly high correlation.

Bilateral Flexor Digitorum Accessorius Longus Precipitating Bilateral Tarsal Tunnel Syndrome: A Case Report

CASE

A 29-year-old woman presented with bilateral tarsal tunnel syndrome caused by bilateral flexor digitorum accessorius longus, experiencing immediate relief of symptoms after surgical intervention through 1 year.

CONCLUSION

Accessory muscles can cause compressive neuropathies in multiple areas of the body. In patients who have FDAL as the cause of their tarsal tunnel syndrome, surgeons should have a high index of suspicion of bilateral FDAL if the same patient develops similar contralateral symptoms.

Tortuosity and Pulsatility of the Tibial Artery - Two Case Reports of a Rare Etiology of Tarsal Tunnel Syndrome

Tarsal tunnel syndrome is a neuropathic compression of the tibial nerve and its branches on the medial side of the ankle. It is a challenging diagnosis that constitutes symptoms arising from damage to the posterior tibial nerve or its branches as they proceed through the tarsal tunnel below the flexor retinaculum in the medial ankle, easily forgotten and underdiagnosed. Neural compression by vascular structures has been suggested as a possible etiology in some clinical conditions. Tibial artery tortuosity is not that rare, but only that it affects the nerve can cause tarsal tunnel syndrome. Therefore, a study care must be taken to avoid false-positive errors.

Acute Tarsal Tunnel Syndrome After Total Ankle Arthroplasty With Varus Deformity

BACKGROUND

A 54-year-old woman presented with varus ankle arthritis, which was corrected with total ankle arthroplasty (TAA). Immediately postoperatively, she was insensate throughout the plantar foot. After seven weeks, she underwent tarsal tunnel release, and the tibial nerve was found to be intact. Plantar sensation improved by one week after exploration with neurolysis and was completely intact at one year.

CONCLUSION

Loss of plantar sensation can occur following TAA for varus arthritic deformity. One potential cause is tibial nerve compression from tightening the laciniate ligament, resulting in acute tarsal tunnel syndrome. The condition can be remedied with early recognition and tarsal tunnel release. Level of Evidence: V.

Tarsal tunnel syndrome secondary to accessory or variant muscles: a clinical and anatomical systematic review

PURPOSE

Many etiologies are known to lead to a tarsal tunnel syndrome (TTS). One rare cause is mass-occupying lesions, and particularly accessory or variant muscles (AVM). This study aimed to systematically collect published clinical cases of TTS caused by AVM.

METHODS

An electronic literature search was conducted from inception to April 2021. The diagnosis of AVM should be reported in one of the following methods: ultrasonography, magnetic resonance imaging (MRI), or per-operatively. Data extraction included types and prevalence of accessory muscles, clinical presentation and diagnosis, and treatment modalities. Twenty-five studies were identified with a total 39 patients (47 ankles).

RESULTS

The prevalence of TTS was reported in only two studies (9%). Forty-nine AVM were identified with the accessory flexor digitorum longus being the most common (52%). The most common sign/symptoms were tenderness (78.7%), pain (82.9%), dysesthesia (57.4%), Tinel sign (44.6%), and a swelling (25.5%). Decompression and excision were the most commonly performed procedures. Four accessory/variant muscles in the ankle have the potential to induce a tarsal tunnel syndrome.

CONCLUSION

This review highlights the clinical and imagery specificities of TTS secondary to accessory or variant muscles. Mass-occupying etiology should be included in the list of differential diagnoses whenever a posterior tibial nerve compression is suspected.

Tarsal Tunnel Syndrome: An Ultrasound Pictorial Review

Tarsal tunnel syndrome may be idiopathic or may be caused by various conditions: bone disease, thickening of the retinaculum, hematoma, or iatrogenic nerve damage; tendinopathy or tenosynovitis; the presence of supernumerary muscles such as an accessory soleus, peroneocalcaneus internus, or accessory flexor digitorum muscle; bone or joint disorders; expansile tumors or cysts; and venous aneurysm or kinking of the tibial artery. The purpose of this article is to describe and illustrate most of the causes of tarsal tunnel syndrome, as diagnosed by ultrasound, which is a practical, inexpensive method.

Accessory Flexor Digitorum Longus Presenting as Tarsal Tunnel Syndrome: A Case Series

ABSTRACT

Tarsal tunnel syndrome (TTS) typically occurs from extrinsic or intrinsic sources of compression on the tibial nerve. We present 3 cases of patients, all of whom have a prolonged time to diagnosis after evaluation with multiple specialties, with foot pain ultimately secondary to an accessory flexor digitorum longus muscle causing TTS. The literature describing the association between TTS and accessory musculature has been limited to single case reports and frequently demonstrate abnormal electrodiagnostic testing. In our series, 2 cases had normal electrodiagnostic findings despite magnetic resonance imaging (MRI) that later revealed TTS and improvement with eventual resection. A normal electromyogram should not preclude the diagnosis of TTS and MRI of the ankle; it should be considered a useful diagnostic tool when examining atypical foot pain.

Electrophysiological Study of the Tibial Nerve Across the Tarsal Tunnel in Distal Symmetric Diabetic Polyneuropathy

OBJECTIVE

The aim of the study was to demonstrate abnormalities of motor conduction of the tibial nerve across the tarsal tunnel in type 2 diabetes.

DESIGN

One hundred twenty-four consecutive patients (mean age = 66.6 yrs, 62.1% male) with distal symmetric diabetic polyneuropathy clinically diagnosed were prospectively enrolled. Nerve conduction studies of deep peroneal, tibial, superficial peroneal, medial plantar, and sural nerves and standard needle electromyography in the lower limbs were performed. Demographic, anthropometric, and clinical findings were collected.

RESULTS

Motor conduction velocity of the tibial nerve across tarsal tunnel was slowed in 60.5% of patients; another 4% showed conduction block across tarsal tunnel without reduction of motor conduction velocity. Overall percentage of abnormalities across tarsal tunnel (64.5%) exceeds that of the sensory conduction velocities of proximal sural and superficial peroneal nerves. Abnormal tibial motor conduction velocity across tarsal tunnel represents the most common abnormality among all motor nerve conduction study parameters and significantly correlates with hemoglobin level, diabetic neuropathic index score, and diabetic complications frequency.

CONCLUSIONS

Tibial conduction abnormalities across tarsal tunnel are the most sensitive motor parameter in distal symmetric diabetic polyneuropathy, second only to conduction abnormalities of sensory/mixed distal nerves of the feet. The use of nerve conduction studies across tarsal tunnel of the tibial nerve may be useful in the electrophysiological protocol to confirm the diagnosis of distal symmetric diabetic polyneuropathy.

Mal-union of sustentaculum tali fracture with talo-calcaneal coalition leading to tarsal tunnel syndrome: A case report

Displaced isolated fractures of sustentaculum tali are rare. Inadequate treatment of these injuries can rarely lead to non-union or mal-union and in most cases are treated non-surgically. We report a unique case of undiagnosed mal-union of sustentaculum tali in the setting of underlying tarsal coalition that resulted in symptoms of tarsal tunnel. Osteotomy and excision of the mal-united fragment and coalition along with decompression of the tarsal tunnel was performed. The patient had immediate improvement in pain and the paraesthesia recovered by the end of 6 weeks post-operatively. The Foot and Ankle disability score (FADI) score improved from 26.0 pre-operatively to 96.2 at 3 years' follow-up. This case highlights that isolated fractures of sustentaculum tali warrant advanced imaging and surgical reduction and fixation may be appropriate to avoid long-term disability where displacement compromises the tarsal tunnel or function of the subtalar joint.

Tarsal Tunnel Syndrome Caused by an Occult Schwannoma of the Posterior Tibial Nerve: Avoidance of Delay in Diagnosis

Tarsal tunnel syndrome (TTS), resulting from compression of the posterior tibial nerve (PTN) within the tarsal tunnel, is a relatively uncommon entrapment neuropathy. Many cases of tarsal tunnel syndrome are idiopathic; however, some causes, including space-occupying lesions, may lead to occurrence of TTS symptoms. Schwannoma, the most common tumor of the sheath of peripheral nerves, is among these space-occupying lesions, and may cause TTS when it arises within the tarsal tunnel, and it may mimic TTS even when it is located outside the tarsal tunnel and cause a significant delay in diagnosis. The possibility of an occult space-occupying lesion compressing the PTN should be kept in mind in the differential diagnosis of TTS, and imaging studies that are usually not used in entrapment neuropathies may be of importance in such patients. This case report presents a 65-year-old woman with TTS symptoms and neurophysiologic findings secondary to an occult schwannoma of the PTN proximal to the tarsal tunnel. Avoidance of delay in diagnosis in secondary cases is emphasized.

Atypical musculoskeletal manifestations on flexor hallucis longus tendon of gout causing tarsal tunnel syndrome in diabetic patients: A case report

RATIONALE

Deposition of tophus is a common feature in chronic gout; however, signs and symptoms are not always well-pronounced in cases of uncommon sites. We report a rare case with a tophaceous tendonitis on the flexor hallucis longus (FHL) tendon with tarsal tunnel syndrome (TTS). This is the first surgical case of TTS by gouty tophi in FHL.

PATIENT CONCERNS

A 55-year-old woman presented with a 6-month history of mild discomfort at the right foot, which gradually worsened in the past 3 weeks. The patient visited our outpatient clinic due to persistent and aggravating foot pain and swelling around the tarsal tunnel.

DIAGNOSIS

The patient was diagnosed with hyperuricemia and diabetes mellitus with chronic kidney disease, and did not receive regular antigout treatments. Paresthesia was found along the distribution of medial and plantar nerve and tinel test was positive on tarsal tunnel. Biochemical examination showed she had raised serum uric acid (10.6 mg/dL) and decreased estimated glomerular filtration rate (69 mL/min/1.73 m). Conventional radiography examination showed negative pathology except soft tissue swelling. Magnetic resonance imaging revealed a fusiform mass within the FHL tendon and fluid collection around tarsal tunnel.

INTERVENTIONS

Surgical exploration was performed to remove the mass. Inflammation fluid exploded out from FHL tendon sheath, which was later proven to have infiltration of monosodium urate crystal. Superficial dissection revealed a white chalky mass and posterior tibial nerve was significantly compressed by the tophus mass.

OUTCOMES

The mass was removed and the symptoms were relieved at immediate postoperative period.

LESSONS

A tophaceous tendonitis on FHL tendon can cause TTS and surgical decompression of the gout lesion can reduce the symptoms.

Tarsal tunnel syndrome caused by an uncommon ossicle of the talus: A case report

RATIONALE

Tarsal tunnel syndrome (TTS) is a compressive neuropathy of the posterior tibial nerve or one of its branches within the tarsal tunnel that is often caused by a variety of space-occupying lesions, such as ganglia, lipomas, varicosities, neural tumors, trauma, or systemic disease. The os sustentaculi is a small accessory bone, bridged to the posterior aspect of the sustentaculum tali by fibrocartilage. To the best of our knowledge, this is a rare case of successful treatment of TTS caused by the os sustantaculi.

PATIENT CONCERNS

A 37-year-old male presented with insidious onset of right ankle and foot pain for 1 year. He also complained of a tingling sensation and paresthesia from the plantar and medial aspect of the forefoot to the middle foot area along the main distribution of the medial plantar nerve. The symptoms were mild at rest, but increased upon prolonged walking. He had an ankle sprain history during a football game 2 years previously and recurrent ankle sprains had occurred more frequently in this ankle since that trauma.

DIAGNOSES

Plain standing anteroposterior and lateral view radiographic findings of the right ankle reveled an accessory ossicle located posterosuperomedial to the sustentaculum tali. A computed tomography scan showed that the ossicle articulated between the talus and calcaneus. A magnetic resonance image revealed mild bone marrow edema in the ossicle and medial displacement of the tarsal structures.

INTERVENTIONS

Surgery was performed under general anesthesia. The ossicle was delineated from its surrounding structures and was removed. Tension on the nerve was released.

OUTCOMES

The patient's pain and hypoesthesia were immediately relieved, and the tingling sensation disappeared 6 months after surgery. The patient had no complications or recurrence of symptoms at the 1-year follow-up.

[Tarsal tunnel syndrome secondary to venous insufficiency. Case report]

Tarsal tunnel syndrome is defined as an extrinsic and/or intrinsic compressive neuropathy of the posterior tibial nerve or one of its branches. Its causes include venous insufficiency. Clinical case: 51 year-old female patient from León, Guanajuato. Hypertensive, with Guillain-Barré syndrome for eight years, vascular insufficiency and obesity. Her condition started with left ankle and heel pain; she was treated with NSAIDs and rehabilitation and achieved partial improvement. X-rays and MRI of the left ankle showed posterior impingement. She underwent arthroscopy and improved but one month later she presented with severe pain in the left ankle and sole and dysesthesias. Electromyography showed a lesion of the posterior tibial nerve. We had the patient's case history, preoperative tests, and dorsoplantar and lateral X-ray views. The arthroscopic diagnosis was Flexor Hallucis Longus (FHL) tendinitis, synovitis and posterior ankle impingement. Synovectomy, decompression and smoothening of the FHL tendon were performed. The patient did poorly and underwent electromyography with axonotmesis of the medial plantar branch. After the nerve was released, Lazorthes venous plexus was found to be tortuous and compressing the entire nerve tract. The possible causes for this include intrinsic compression secondary to tumors, and anatomical changes of the tarsal tunnel. However, less often varices may confound the diagnosis and cause irreversible damage if not treated timely. The patient is currently pain free and can walk, has mild dysesthesias of the first toe and limited flexion.

[Anatomical variants of the medial calcaneal nerve and the Baxter nerve in the tarsal tunnel]

The tarsal tunnel is composed of the posterior border of the medial malleoulus, the posterior aspect of the talus and the medial aspect of the calcaneus. The medial calcaneal nerve emerges from the posterior aspect of the posterior tibial nerve in 75% of cases and from the lateral plantar nerve in the remaining 25%. Finally, the medial calcaneal nerve ends as a single terminal branch in 79% of cases and in numerous terminal branches in the remaining 21%. To describe the anatomical variants of the posterior tibial nerve and its terminal branches. To describe the steps for tarsal tunnel release. To describe Baxter nerve release. The anatomical variants of the posterior tibial nerve and its terminal branches within the tarsal tunnel were studied. Then the Lam technique was performed; it consists of: 1) opening of the laciniate ligament, 2) opening of the fascia over the abductor hallucis muscle, 3) exoneurolysis of the posterior tibial nerve and its terminal branches, identifying the emergence and pathway of the medial calcaneal branch, the lateral plantar nerve and its Baxter nerve branch and the medial plantar nerve. Baxter nerve was found in 100% of cases. In 100% of cases in our series the nerve going to the abductor digiti minimi muscle of the foot was found; 87.5% of cases had two terminal branches. The dissections proved that a crucial step was the release of the distal tarsal tunnel.

Tarsal tunnel syndrome and flexor hallucis longus tendon hypertrophy

Tarsal tunnel syndrome (TTS) defines an entrapment neuropathy of the posterior tibial nerve or one of its branches, within the tarsal tunnel. Numerous etiologies have been described explaining this entrapment, including trauma, space-occupying lesions, foot deformities, etc. We present an unreported cause of a space-occupying lesion in the etiology of TTS, namely the combination of a hypertrophic long distally extended muscle belly of the flexor hallucis longus and repetitive ankle motion. Surgical debulking of the muscle belly in the posterior ankle compartment resolved all symptoms.

Tarsal tunnel syndrome in a patient on long-term peritoneal dialysis: case report

Tarsal tunnel syndrome (TTS) is defined as the entrapment of the posterior tibial nerve in the tarsal tunnel of the ankle. The etiologies of tarsal tunnel syndrome are mainly the presence of a ganglion, osseous prominence with tarsal bone coalition, trauma, varicose veins, neurinoma, hypertrophy of the flexor retinaculum, or systemic disease (rheumatoid arthritis, ankylosing spondylitis). However, no specific cause can be identified in some cases. Patients with chronic renal failure tend to develop peripheral nerve entrapment and carpal tunnel syndrome is the best-known peripheral entrapment neuropathy among them. Contrary to carpal tunnel syndrome, tarsal tunnel syndrome is observed less frequently in chronic renal failure patients. The common presenting symptoms of TTS are paresthesias and/or pain in the plantar side of the foot. Motor symptoms are rarely detected. Diagnosis is made primarily by electroneuromyographic studies and physical examination. Surgery is the treatment of choice and the outcome is generally favourable. In this report, we present a patient with tarsal tunnel syndrome complicating peritoneal dialysis.

Neurilemoma of the posterior tibial nerve and tarsal tunnel syndrome

Tarsal tunnel syndrome is defined as a compressive neuropathy of the posterior tibial nerve in the tarsal canal. A neurilemoma is an uncommon, benign, encapsulated neoplasm derived from Schwann cells. We present a case of tarsal tunnel syndrome caused by this rare space-occupying lesion.

The effect of the tarsal joint positions on the tibial nerve motor action potential latency in dog: electrophysiological and anatomical studies

This study has been carried out to determine the effect of neutral position, hyperextension and hyperflexion of the tarsal joint on the tibial nerve, motor action potential latency and tarsal canal compartment pressure in dogs with the aid of electrophysiological and anatomical methods. Totally twenty healthy mongrel dogs were used. Latency of motor nerve action potential (MNAPL) studies of tibial nerve via surface stimulating and needle recording electrodes was performed on right hind limbs of all the dogs. The compartment pressures of the tarsal canal with the pressure transducer were determined from both limbs from ten of the dogs. In one dog, tarsal regions of both left and right limbs were demonstrated using magnetic resonance imaging (MRI). Two dogs were euthanatized and tarsal regions of the dogs were sectioned for correlative anatomy. Nerve conduction studies showed that the MNAP latency of the tibial nerve were 3.55 +/- 0.097 ms, 3.76 +/- 0.087 ms and 3.39 +/- 0.097 ms in neutral, hyperextension and hyperflexion positions, respectively. Hyperflexion of the tarsal joint caused prolongation of the MNAP latency of the tibial nerve with the highest pressure value being determined in tarsal canal. From the anatomical viewpoint, the distance between the flexor hallucis longus muscle and the superficial digital muscle was the shortest during hyperflexion and the plantar branch of saphenous artery, lateral and medial plantar nerves located more laterally in cadaver and MR imaging sections. As a result of this study, it is thought that tarsal region diseases as well as long time splint in the hyperflexion position as applied in the Ehmer sling can affect the compartment pressure and nerve tension because of occupying in the tarsal canal. Raising pressure and nerve stretching in the tarsal canal compartment could cause deficiencies in the conduction velocity of the tibial nerve. This might be a result of tarsal tunnel syndrome in the dog. Clinicians could consider this syndrome in cases of tarsal region diseases as well as application of long time splint in hyperflexion of tarsal joints in dogs.

Tarsal tunnel syndrome caused by a talocalcaneal joint amyloidoma in a long-term haemodialysis patient: a case report

We present a case of tarsal tunnel syndrome caused by an amyloidoma arising from the talocalcaneal joint in a 64-year-old man with a long history of haemodialysis. He presented with numbness in the medial plantar area of the right foot without any antecedent trauma. The numbness was minimal at rest but gradually worsened, causing difficulty, when walking. Paraesthesia was present on the medial sole of the right foot. A positive Tinel-like sign was noted 2.5 cm below the medial malleolus. Magnetic resonance imaging demonstrated a round lesion, 1 cm in diameter, in the calcaneus, which was hypointense on T1-weighted images and hyperintense on T2-weighted images. In addition, a mass, 1 cm in diameter with a signal isointense to that of muscle was found adjacent to the talocalcaneal joint. The medial plantar nerve was decompressed after removing a solid, 1-cm diameter mass from the talocalcaneal joint. At 6 months post surgery, the numbness had completely resolved. No recurrence was observed at the 24-month follow-up.

Tarsal tunnel syndrome in athletes

BACKGROUND

The details of the occurrence of tarsal tunnel syndrome in athletes have not been well documented in the literature, and more data on tarsal tunnel syndrome related to sporting activity are necessary to enable better recognition of this condition.

HYPOTHESIS

Sporting activities make athletes vulnerable to the occurrence of tarsal tunnel syndrome under specific conditions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 1986 and 2002, 18 patients with tarsal tunnel syndrome related to sporting activities were surgically treated, of whom 15 patients (21 feet; mean age, 17.8 years) were competitive athletes and 3 were recreational sports amateurs (4 feet; mean age, 52.7 years). To assess the role of physical factors and sporting activities in making athletes vulnerable to the occurrence of tarsal tunnel syndrome, the authors reviewed the medical charts and evaluated the results of treatment. The mean duration of follow-up was 58.6 months.

RESULTS

Activities that triggered tarsal tunnel syndrome were those that applied a heavy burden on the ankle joint such as sprinting, jumping, and performing ashibarai in judo under specific physical conditions. Predisposing underlying physical factors were flatfoot deformity and an existence of talocalcaneal coalition, accessory muscles, and bony fragments around the tarsal tunnel. The majority of patients were able to return to the same sport after treatment.

CONCLUSION

Tarsal tunnel syndrome occurs in athletes involved in strenuous sporting activities, especially when predisposing physical factors are present.

Effect of foot and ankle position on tarsal tunnel compartment volume

BACKGROUND

Tarsal tunnel pressure is increased when the foot and ankle are positioned in eversion or inversion from neutral, aggravating symptoms of tarsal tunnel syndrome in some patients. Space-occupying lesions may cause tarsal tunnel syndrome. We hypothesized that positional change of the foot and ankle from neutral to eversion or inversion causes decreased tarsal tunnel compartment volume that may aggravate symptoms of posterior tibial nerve entrapment.

METHODS

MRI of 13 ankles in nine healthy subjects in three positions (neutral, eversion, inversion) were obtained with respect to the malleolar-calcaneal plane; this plane was defined by the distal tip of the anterior colliculus of the medial malleolus, the medial tubercle of the posterior calcaneal tuberosity, and the lateral tubercle of the posterior calcaneal tuberosity. The borders of the tarsal tunnel noted on the MRI were traced with a computer digitizing apparatus to determine the cross-sectional area of the tarsal tunnel on each image, and the slice thickness and interspace distance for the seven central images were used to calculate tarsal tunnel volume.

RESULTS

The mean tarsal tunnel volume was significantly greater when the foot and ankle were in neutral position (21.5 +/- 0.9 cm(3)) than in either full eversion (18.0 +/- 0.9 cm(3); p = or < 0.001) or inversion (20.3 +/- 1.0 cm(3); p = or < 0.001).

CONCLUSIONS

The results support the hypothesis that eversion and inversion of the foot and ankle cause decreased compartment volume of the tarsal tunnel and increased tarsal tunnel pressure that may contribute to symptoms of posterior tibial nerve entrapment in tarsal tunnel syndrome.

CLINICAL RELEVANCE

Neutral immobilization of the foot and ankle may relieve symptoms of posterior tibial nerve entrapment in tarsal tunnel syndrome by minimizing pressure on the nerve and maximizing tarsal tunnel compartment volume available for the nerve.

Ultrasonography in tarsal tunnel syndrome

OBJECTIVE

The purpose of this study was to clarify the diagnostic value of ultrasonography in tarsal tunnel syndrome.

METHODS

Seventeen patients (17 feet) with tarsal tunnel syndrome were treated between 1988 and 2003. Preoperative ultrasonography was performed, and the cause of the syndrome was confirmed intraoperatively in all cases. Long and short axes of the tarsal tunnel were scanned to ascertain the presence of any space-occupying lesion.

RESULTS

The causes of tarsal tunnel syndrome, as confirmed by surgery, were ganglia (n = 10), talocalcaneal coalition (n = 1), talocalcaneal coalition associated with ganglia (n = 3), and varicose veins (n = 3). Among the cases involving ganglia, hypoechoic or anechoic regions were observed. The mean sizes +/- SD of these regions were 19.4 +/- 8.8 mm in the long axis, 15.2 +/- 6.3 mm in the short axis, and 10.4 +/- 3.8 mm in depth. Of these, 3 ganglia were not clearly palpable before surgery and were small: 10 x 10 x 7, 13 x 11 x 9, and 9 x 8 x 7 mm. Among the cases involving talocalcaneal coalition, ultrasonography indicated a beak-shaped bony process on the short axis images. Although these 3 cases were associated with ganglia, this could not be determined by preoperative palpation.

CONCLUSIONS

As a diagnostic imaging technique for tarsal tunnel syndrome, ultrasonography is extremely useful for identifying space-occupying lesions. Ultrasonography should be performed routinely in patients with suspected tarsal tunnel syndrome.

[Treatment of neurological component of venous insufficiency of the lower extremities]

Based on a personal experience of the treatment of venous insufficiency of low extremities, was selected a group of 31 patients from 167 patients with trophic disorders resulted from venous insufficiency of low extremities. The patients of the selected group had along typical venous insufficiency related symptoms a neurological syndrome which was typical for the tarsal canal. Neurological disorders in 26 patients may be caused by a long persisting ulcer and chronic regional inflammation against venous hypertension. The syndrome of the tarsal canal in 5 patients may develop as recurrence of venous disease following the surgical operation after Linton. The patients of the selected group underwent final correction of venous hemodynamics, decompression and neurolysis of posterior tibial nerve in the tarsal canal.

Tarsal tunnel syndrome caused by ganglion

We report a case of delayed diagnosis of tarsal tunnel syndrome caused by a ganglion arising from the talo-calcaneal joint. Unusually the symptoms were mainly due to the lateral planter nerve compression with a positive Tinel's sign. A surgical decompression was successful in relieving the dysaesthesia in spite of a 7 years history.

Peripheral nerve entrapments

Peripheral nerve entrapment is a rare, but important, cause of foot and ankle pain that often is underdiagnosed and mistreated. A peripheral nerve may become entrapped anywhere along its course, but certain anatomic locations are characteristic. Clinically,nerve entrapment is divided into three stages: in stage I patients feel rest pain and intermittent paresthesias which are worse at night; in stage II, continued nerve compression leads to paresthesias, numbness, and, occasionally, muscle weakness that does not disappear during the day, and in stage III, patients describe constant pain, muscle atrophy, and permanent sensory loss. Diagnostic confusion abounds because of the multiple etiologies of peripheral nerve entrapments and their complex physical and temporal relation. A thorough understanding of the causes of peripheral nerve entrapments, the anatomic course and variation of the peripheral nerves, the diagnostic modalities, and the treatment options can simplify this complex problem.

Tarsal tunnel syndrome caused by epineural ganglion of the posterior tibial nerve: report of 2 cases and review of the literature

Ganglia within the posterior tibial nerve is a rare condition. The authors report 2 cases of epineural ganglion of the posterior tibial nerve, causing tarsal tunnel syndrome. Both cases presented with numbness on the plantar surface of the foot. Magnetic resonance imaging showed the presence of the cyst within the tarsal tunnel. During surgery, these cysts were found within the epineurium of the posterior tibial nerve and were successfully removed without damage to nerve fibers. Both patients were free of symptoms after surgery. Ganglion cysts in the peripheral nerve are either intrafascicular or epineural. Intrafascicular ganglia present beneath the epineurium and involve the nerve fibers, whereas epineural ganglia are located in the epineurium and do not involve the nerve fibers. A review of the literature discusses these concepts. The authors suggest that epineural ganglion should be clinically distinctive from an intrafascicular ganglion because of the differences in surgical treatment, postoperative nerve function, and the recurrence rate.

Backpacking-Induced Paresthesias

OBJECTIVE

To evaluate the presence of numbness and paresthesias among long-distance backpackers on the Appalachian Trail.

METHODS

Backpackers who hiked a minimum of 7 days were interviewed while hiking. Following their hike, a written questionnaire was mailed to the participants that explored the incidence of injuries and illnesses among hikers. Paresthesias were defined as either numbness or "phantom, burning, or shooting pains." A case-control analysis of risk factors for paresthesias was performed.

RESULTS

Paresthesias were reported by 34% (96 of 280) of the backpackers completing the study. They included ulnar paresthesias (n = 4), meralgia paresthetica (n = 10), tarsal tunnel syndrome (n = 6), digitalgia paresthetica (n = 21), and nonspecific paresthesias (n = 61). The most common symptom was numbness: 81% (78 of 96). Significant risk factors included a distance of >2000 miles (relative risk [RR] = 1.3; 95% CI, 1.1-1.6; P = .01) and the duration of hiking (RR = 2.0; 95% CI, 1.2-3.2; P = .004) for the longest quartile. Nonsignificant factors included backpack weight, initial body weight, percentage of weight loss, running shoe usage, and multivitamin usage. Ninety-eight percent of the paresthesias (94 of 96) had resolved by the time of follow-up (median = 30 days).

CONCLUSIONS

Paresthesias were a surprisingly common complaint among long-distance backpackers. Although they were distressing during backpacking, these neuropathies were self-limited and resolved after completion of hiking.

Failed tarsal tunnel syndrome surgery

Failed tarsal tunnel syndrome surgeries are better prevented than treated. Outcomes for revision procedures are significantly worse than for primaries. Failures should be treated with conservative measures first, then surgery for refractory cases. An adequate release must be ensured, and associatedpathologies must be addressed. One should consider containment procedures for adhesive neuritis and PNS for intraneural or intractable pain.

Tarsal tunnel syndrome associated with an accessory muscle

Between 1986 and 1999, we surgically treated 41 patients (49 feet) with Tarsal Tunnel Syndrome (TTS) in whom seven (eight feet) were associated with an accessory muscle. An accessory flexor digitorum longus muscle was present in six patients, and an accessory soleus muscle was in one patient (both feet). Three of them were males and four females, with the mean age of 33.1 years (12 to 59 years). The mean interval from the onset of symptoms to operation was 7.5 months (range, six to nine months). All patients with an accessory muscle had a history of trauma or strenuous sporting activity. The diagnosis of TTS was made based on physical findings in all the patients (eight feet) and confirmed in five patients (six feet) by electrophysiological examination. Imaging examinations (radiography, ultrasonography, MRI) revealed abnormal bone and soft tissue lesions in and around the tarsal tunnel. Preoperative signs and symptoms disappeared average 4.1 months after decompression of the tibial nerve in addition to excision of the muscle. No functional deficit was observed at final follow-up (24 to 88 months).

An unusual presentation of tarsal tunnel syndrome caused by an inflatable ice hockey skate

BACKGROUND

Tarsal tunnel syndrome is a rare form of entrapment neuropathy. In athletes, it is usually the result of repetitive activity, local injury or a space-occupying lesion. Rarely, athletic footwear has been described as the primary cause of this syndrome.

METHODS

A 37-year-old male recreational hockey player was examined clinically and electrophysiologically because of spreading numbness in the toes of his left foot while playing hockey and wearing inflatable ice hockey skates designed to promote a better fit.

RESULTS

Clinical and electrophysiological studies revealed evidence of left medial and lateral plantar nerve involvement. Reduced amplitudes of mixed and motor plantar nerve responses with fibrillation potentials and positive sharp waves and no evidence of conduction block suggest that the primary pathology was axonal loss. Follow-up examination showed significant clinical and electrophysiological improvement after the patient stopped wearing his inflatable ice hockey skates.

CONCLUSION

We report an unusual case of tarsal tunnel syndrome caused by an inflatable ice hockey skate. The patient improved clinically and electrophysiologically when he stopped wearing the boot.

Recognition of the flexor digitorum accessorius longus

The flexor digitorum accessorius longus muscle was observed during a cadaveric surgery course on the foot and ankle for third-year podiatric medical students. The cadaveric foot had been amputated just proximal to the ankle level so that the muscle origin could not be determined; its insertion, however, was found to be into the flexor digitorum longus tendon, just before the tendon split into its digital slips. This article reviews the literature on the muscle and its clinical implications and describes and shows the muscle as it was seen in this case.

Tarsal tunnel syndrome - the effect of the associated features on outcome of surgery

Between 1989 and 2000, 16 patients underwent surgery for tarsal tunnel syndrome; 12 patients (13 feet) were available for follow-up at a mean of 83 (12-143) months. The symptoms had resolved in six feet, were improved in four, were unchanged in two and recurred after five years in one. Better results are obtained in patients who have space occupying lesions than in those in whom the aetiology is idiopathic or post-traumatic or those with foot deformities.

Acute tarsal tunnel syndrome following partial avulsion of the flexor hallucis longus muscle: a case report

An acute posterior tibial nerve compression from a partially ruptured flexor hallucis longus (FHL) muscle is reported. This etiology for acute tarsal tunnel syndrome has not been previously described. A 17-year-old male sustained multiple injuries in a motor vehicle accident, including a tibial shaft fracture and a posterior medial right ankle laceration of the same limb. The injured limb had no sensation on the plantar aspect of the foot and heel, decreased active great toe flexion, and associated leg pain. Exploration of the posterior tibial nerve for presumed laceration revealed the nerve to be intact, but compressed in a tense tarsal tunnel from a retracted partially ruptured flexor hallucis longus tendon. Decompression of the tunnel and resection of the devascularized muscle resulted in complete neurologic recovery.

Tarsal tunnel syndrome caused by talocalcaneal coalition

Tarsal tunnel syndrome caused by talocalcaneal coalition is uncommon. We presented the ultrasonography (US) and magnetic resonance imaging findings of this disease. This is, to our knowledge, the first case report describing the US findings in tarsal tunnel syndrome caused by talocalcaneal coalition.

Tarsal tunnel syndrome secondary to an accessory muscle: a case report

The flexor digitorum accessorius longus is a rare muscular anomaly that has been reported as one of the etiologies of tarsal tunnel syndrome. The authors provide a case report of a patient with tarsal tunnel syndrome that resolved with resection of the flexor digitorum accessorius longus. The patient remains asymptomatic 40 months following surgery.

Nerve conduction studies of lower extremities in pes planus subjects

Pes planus is a condition in which the medial longitudinal arch is depressed. Pedoscop, eyeball visualization, ink mat and roentgenography were used in clinical evaluation. We performed nerve conduction studies on both feet of 28 pes planus subjects. Our results demonstrated mild prolongation distal latency of the medial and lateral plantar sensory nerves, and delayed sensory conduction velocity of the medial plantar sensory nerve. The presence of electrodiagnostic abnormalities in this study population helps to substantiate the presence of compression neuropathy of the medial or lateral plantar nerve in pes planus subjects.

Tarsal tunnel syndrome

Most authors agree that surgical decompression is the treatment of choice for tarsal tunnel syndrome when conservative treatment fails. Overall, the results of surgical treatment for tarsal tunnel have been favorable. Studies have shown that surgical release improves or resolves symptoms of tarsal tunnel syndrome in 85% to 90% of cases.

Tarsal tunnel syndrome secondary to neurilemoma--a case report

Peripheral nerve entrapment syndromes in the foot include those symptom complexes that are primarily neurologic in origin and result from embarrassment to any of the peripheral nerve trunks or branches of the foot. Tarsal tunnel syndrome usually is precipitated by compression of the tibial nerve posterior and distal to the medial malleolus. A neurilemoma is relatively uncommon in the foot. It is usually a solitary tumor that is almost exclusively benign and can be removed without jeopardizing the integrity of the nerve. Diagnosis is based on a thorough history and clinical pictures. Certain diagnostic modalities, ultrasound and MRI, have been employed to aid in diagnosis. Surgical excision of the tumor remains the treatment of choice.

Hypertrophic sustentaculum tali causing a tarsal tunnel syndrome: a case report

A case report of tarsal tunnel syndrome caused by a hypertrophic sustentaculum tali is presented. This is the first reported case secondary to this etiology. Complete resolution of the patient's symptoms has been obtained through resection of the hypertrophic anatomy. The authors also discuss possible etiologies of tarsal tunnel syndrome.