Anterior Tarsal Tunnel Syndrome: Entrapment of the Articular Branch of Deep Peroneal Nerve: A Case Report.

CASE: A 28-year-old male patient who injured his ankle 2 years ago presented with unilateral ankle pain, tingling, and numbness for 1 year. Clinically, tenderness and positive Tinel sign were localized on anterior aspect of ankle. On exploration, deep peroneal nerve and mainly its articular branch were encased in fibrotic tissue. Decompression of both nerves resulted in symptomatic relief after surgery. CONCLUSION: High index of suspicion, a thorough medical history, meticulous clinical examination, complete knowledge of nerve anatomy, proper radiological studies, and careful surgical decompression are all necessary for the diagnosis and management of such atypical cases.

Distal Tibial Mononeuropathy From Compression by the Posterior Tibial Artery: Clinical-Electrophysiological-Ultrasonographic Correlations.

SUMMARY: The tibial nerve is bound tightly to the posterior tibial artery in the tarsal tunnel where expansion capacity is limited. Therefore, the nerve may be vulnerable to, and damaged by chronic pulsatile trauma from an atypically positioned overriding artery, labeled "punched-nerve syndrome". In this article, we present a 49-year-old woman who presented with two months of severe burning pain in the left medial ankle and sole of the foot without antecedent trauma. Neurological examination identified dysesthetic sensation to light touch in the left medial sole of the foot, and both active and passive dorsiflexion worsened the painful paresthesia. Nerve conduction studies demonstrated a reduced left medial plantar mixed nerve action potential amplitude, 50% less than the right. High-resolution ultrasound (HRUS) showed an increased left tibial nerve cross-sectional area of 26 mm2 (normal <22.3 mm2) at the level of the ankle with side-to-side difference of 6 mm2 (normal <5.7 mm2). The distal tibial nerve and its medial plantar branch were atypically positioned immediately deep to the left posterior tibial artery and abnormally flattened with focal enlargement of the nerve on longitudinal view. Dynamic analysis demonstrated the nerve being compressed with each pulsation of the tibial artery immediately above. Active dorsiflexion of the ankle narrowed the space underneath the flexor retinaculum resulting in further compression of the nerve against the artery. In conclusion, HRUS as an adjunct to electrophysiological studies identified punched-nerve arterial compression as an etiology of tarsal tunnel syndrome.

Impact of Dynamic Change of Meandering of Parallel Artery to the Idiopathic Tarsal Tunnel Syndrome.

In idiopathic tarsal tunnel syndrome (TTS), walking seems to make symptoms worse. The findings imply that an ankle movement dynamic component may have an impact on the etiology of idiopathic TTS. We describe how the ankle movement affects the nerve compression caused by the surround tissue, particularly the posterior tibial artery. We enrolled 8 cases (15 sides) that had TTS surgery after tarsal tunnel (TT) MRI preoperatively. Dorsiflexion and plantar flexion were the two separate ankle positions used for the T2* fat suppression 3D and MR Angiography of TT. Based on these findings, we looked at how the two different ankle positions affected the posterior tibial artery's ability to compress the nerve. Additionally, we assessed the posterior tibial artery's distorted angle. We divided the region around the TT into four sections: proximal and distal to the TT and proximal half and distal half to the TT. Major compression cause was posterior tibial artery. Most severe compression point was proximal half in the TT in all cases without one case. In each scenario, the nerve compression worsens by the plantar flexion. The angle of the twisted angle of the posterior tibial artery was significantly worsened by the plantar flexion. In idiopathic TTS, deformation of posterior tibial artery was the primary compression component. Nerve compression was exacerbated by the plantar flexion, and it was attributable with the change of the distorted angle of the posterior tibial artery. This could be a contributing factor of the deteriorating etiology by walking in idiopathic TTS.

Magnetic Resonance Imaging Findings in Patients with Tarsal Tunnel Syndrome.

Tarsal tunnel syndrome (TTS) is a common entrapment syndrome whose diagnosis can be difficult. We compared preoperative magnetic resonance imaging (MRI) and operative findings in 23 consecutive TTS patients (28 sides) whose mean age was 74.5 years. The 1.5T MRI sequence was 3D T2* fat suppression. We compared the MRI findings with surgical records and intraoperative videos to evaluate them. MRI- and surgical findings revealed that a ganglion was involved on one side (3.6%), and the other 27 sides were diagnosed with idiopathic TTS. MRI visualized the nerve compression point on 23 sides (82.1%) but failed to reveal details required for surgical planning. During surgery of the other five sides (17.9%), three involved varices, and on one side each, there was connective tissue entrapment or nerve compression due to small vascular branch strangulation. MRI studies were useful for nerve compression due to a mass lesion or idiopathic factors. Although MRI revealed the compression site, it failed to identify the specific involvement of varices and small vessel branches and the presence of connective tissue entrapment.

An update on imaging of tarsal tunnel syndrome.

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve (TN) within the tarsal tunnel (TT) at the level of the tibio-talar and/or talo-calcaneal joints. Making a diagnosis of TTS can be challenging, especially when symptoms overlap with other conditions and electrophysiological studies lack specificity. Imaging, in particular MRI, can help identify causative factors in individuals with suspected TTS and help aid surgical management. In this article, we review the anatomy of the TT, the diagnosis of TTS, aetiological factors implicated in TTS and imaging findings, with an emphasis on MRI.

Síndrome del túnel del tarso: análisis clínico-imagenológico de una serie de casos / Tarsal tunnel syndrome: Clinical-imaging analysis of a case series

Antecedentes: Revisión retrospectiva de pacientes con diagnóstico de síndrome del túnel del tarso (STT) tratados quirúrgicamente. Método: Serie retrospectiva de pacientes con diagnóstico de STT operados entre los años 2005 y 2020 en un mismo centro. Se analizan variables como edad, género, lado, nervio o rama afectada, clasificación, tipo de estudio imagenológico, resultado biopsia, tasa de infección, tasa recurrencia, secuelas, entre otras. Resultados: Se incluyen ocho hombres y dos mujeres con edad promedio de 47 años (rango 34-67) y seguimiento promedio de 62,2 meses (rango 2-149). Todos los casos se relacionan con una compresión intrínseca. La causa más frecuente fue la presencia de quiste (40%), seguida de adherencias perineurales (20%). El nervio tibial posterior fue el más afectado (50%) y 30% la rama plantar medial. La ecografía (70%) y resonancia magnética (50%) fueron los estudios más solicitados. No hubo casos de infección postoperatoria. Hubo tres pacientes que presentaron recurrencia de la lesión requiriendo una nueva cirugía. Conclusiones: El STT es una neuropatía que compromete al nervio tibial posterior o a algunas de sus ramas. En general su causa es la compresión del nervio por distintas estructuras como músculos accesorios, gangliones, entre otras. El diagnóstico es eminentemente clínico apoyándose en estudio por imágenes. El tratamiento quirúrgico presenta mejores resultados cuando la causa es una compresión intrínseca, aunque se describen tasas variables de recurrencia.(AU)

Background: Retrospective review of patients with a diagnosis of Tarsal Tunnel Syndrome (TTS) treated surgically. Methods: Retrospective series of patients with diagnosis of TTS operated between 2005 and 2020 in the same center. Variables such as age, sex, side, affected nerve or branch, classification, type of imaging study, biopsy result, infection rate, recurrence rate, sequelae, among others, were analyzed. Results: We included 8 men and 2 women with an average age of 47 years (range 34-67) and an average follow-up of 62.2 months (range 2-149). All cases were related to intrinsic compression. The most frequent cause was the presence of cyst (40%) followed by perineural adhesions (20%). The Posterior Tibial Nerve was the most affected (50%) and 30% the Medial Plantar Branch. Ultrasound (70%) and MRI (50%) were the most requested studies. There were no cases of postoperative infection. There were 3 patients who presented recurrence of the lesion requiring a new surgery. Conclusions: TTS is a neuropathy involving the posterior tibial nerve or some of its branches. In general, it is caused by compression of the nerve by different structures such as accessory muscles and ganglions, among others. The diagnosis is eminently clinical, supported by imaging studies. Surgical treatment presents better results when the cause is an intrinsic compression, although variable recurrence rates are described.(AU)

Tarsal tunnel syndrome: Clinical-imaging analysis of a case series / Síndrome del túnel del tarso: análisis clínico-imagenológico de una serie de casos

Background: Retrospective review of patients with a diagnosis of Tarsal Tunnel Syndrome (TTS) treated surgically. Methods: Retrospective series of patients with diagnosis of TTS operated between 2005 and 2020 in the same center. Variables such as age, sex, side, affected nerve or branch, classification, type of imaging study, biopsy result, infection rate, recurrence rate, sequelae, among others, were analyzed. Results We included 8 men and 2 women with an average age of 47 years (range 34-67) and an average follow-up of 62.2 months (range 2-149). All cases were related to intrinsic compression. The most frequent cause was the presence of cyst (40%) followed by perineural adhesions (20%). The Posterior Tibial Nerve was the most affected (50%) and 30% the Medial Plantar Branch. Ultrasound (70%) and MRI (50%) were the most requested studies. There were no cases of postoperative infection. There were 3 patients who presented recurrence of the lesion requiring a new surgery. Conclusions: TTS is a neuropathy involving the posterior tibial nerve or some of its branches. In general, it is caused by compression of the nerve by different structures such as accessory muscles and ganglions, among others. The diagnosis is eminently clinical, supported by imaging studies. Surgical treatment presents better results when the cause is an intrinsic compression, although variable recurrence rates are described.(AU)

Antecedentes: Revisión retrospectiva de pacientes con diagnóstico de síndrome del túnel del tarso (STT) tratados quirúrgicamente. Método: Serie retrospectiva de pacientes con diagnóstico de STT operados entre los años 2005 y 2020 en un mismo centro. Se analizan variables como edad, género, lado, nervio o rama afectada, clasificación, tipo de estudio imagenológico, resultado biopsia, tasa de infección, tasa recurrencia, secuelas, entre otras. Resultados: Se incluyen ocho hombres y dos mujeres con edad promedio de 47 años (rango 34-67) y seguimiento promedio de 62,2 meses (rango 2-149). Todos los casos se relacionan con una compresión intrínseca. La causa más frecuente fue la presencia de quiste (40%), seguida de adherencias perineurales (20%). El nervio tibial posterior fue el más afectado (50%) y 30% la rama plantar medial. La ecografía (70%) y resonancia magnética (50%) fueron los estudios más solicitados. No hubo casos de infección postoperatoria. Hubo tres pacientes que presentaron recurrencia de la lesión requiriendo una nueva cirugía. Conclusiones: El STT es una neuropatía que compromete al nervio tibial posterior o a algunas de sus ramas. En general su causa es la compresión del nervio por distintas estructuras como músculos accesorios, gangliones, entre otras. El diagnóstico es eminentemente clínico apoyándose en estudio por imágenes. El tratamiento quirúrgico presenta mejores resultados cuando la causa es una compresión intrínseca, aunque se describen tasas variables de recurrencia.(AU)

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.

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.

Ultrasound-Guided Proximal and Distal Tarsal Decompression: An Analysis of Pressures in the Tarsal, Medial Plantar, and Lateral Plantar Tunnels.

Objectives. To analyze the reliability of measurements of tarsal tunnel and medial and lateral plantar tunnel pressures before and after ultrasound-guided release. Measurements taken were guided by ultrasound to improve reliability. This novel approach may help surgeons make surgical decisions. The second objective was to confirm that decompression using ultrasound-guided surgery as previously described by the authors is technically effective, reducing pressure to the tarsal and medial and lateral plantar tunnels. Methods. The study included 23 patients with symptoms compatible with idiopathic tarsal tunnel syndrome (TTS). The first step was to measure intracompartmental pressure of the tarsal tunnel, medial plantar tunnel, and lateral plantar tunnel preoperatively. The second step was ultrasound-guided decompression of the tibial nerve and its branches. Subsequently, pressure was measured again immediately after decompression in the 3 tunnels. Results. After surgery, the mean values significantly dropped to normal values. This represents a validation of effective decompression of the tibial nerve and its branches in TTS with ultra-minimally invasive surgery. Conclusions. The ultrasound-guided surgical technique to release the tibial nerve and its branches is effective, significantly reducing pressure in the tunnels and, thereby, decompressing the nerves.Level of evidence: Level IV.

Can the axial cross-sectional area of the tibial nerve be used to diagnose tarsal tunnel syndrome? An ultrasonography study.

INTRODUCTION: The axial cross-sectional area (CSA) of the tibial nerve can be measured with ultrasonography. In patients who have posteromedial tarsal tunnel syndrome (TTS), there is little information on the nerve's CSA even though this information could be useful for determining whether the nerve is damaged. This led us to carry out a case-control study in which the tibial nerve's axial CSA was measured in healthy patients and in patients with TTS. HYPOTHESIS: The tibial nerve's axial CSA can be used as a diagnostic criterion for TTS. METHODS: Twenty-three patients (27 feet) (11 men, 12 women, mean age=54±14 years), who had clinical and electroneuromyography signs of TTS, were compared to 21 healthy adults (8 men, 13 women, mean age 39±10 years). An ultrasonography examination was carried out to look for a source of nerve compression, then the axial CSA of the tibial nerve was measured 10cm above the tarsal tunnel (lCSA) and inside the tunnel itself (ttCSA). The difference between the two measurements was then calculated: ΔCSA=ttCSA-lCSA. The data were analysed using correlation tests and non-parametric tests, a multivariate linear regression and ROC tests. RESULTS: A compressive cause was found by ultrasonography in 13 patients. The mean values of ttCSA and ΔCSA were 20.1±8.8 mm2 [6-42] vs. 10.3±2.3 mm2 [8-14] (p=0.0001) and 9.8±6.7 mm2 [0-29] vs. -0.2±1.8 mm2 [-3-4] (p<0.0001) in the patients and the controls, respectively. The differences in ΔCSA remained significant in the multivariate analysis after adjusting for age and weight. The best threshold for ttCSA in the TTS group was 15 mm2 with 74% sensitivity and 100% specificity. The best threshold for ΔCSA was 5mm2 with 81% sensitivity and 100% specificity. DISCUSSION: The difference in the measured axial CSA of the tibial nerve by ultrasonography between the posteromedial tarsal tunnel and 10cm above the tunnel is a key data point for the diagnosis of tarsal tunnel syndrome with and without compressive etiology. LEVEL OF EVIDENCE: III, diagnostic case-control study.

Tarsal tunnel syndrome secondary to osteochondroma of the calcaneus: a case report.

BACKGROUND: Tarsal tunnel syndrome is an entrapment neuropathy that can be provoked by either intrinsic or extrinsic factors that compresses the posterior tibial nerve beneath the flexor retinaculum. Osteochondroma, the most common benign bone tumor, seldom occur in foot or ankle. This is a rare case of tarsal tunnel syndrome secondary to osteochondroma of the sustentaculum tali successfully treated with open surgical excision. CASE PRESENTATION: A 15-year-old male presented with the main complaint of burning pain and paresthesia on the medial plantar aspect of the forefoot to the middle foot region. Hard mass-like lesion was palpated on the posteroinferior aspect of the medial malleolus. On the radiological examination, 2.5 × 1 cm sized bony protuberance was found below the sustentaculum tali. Surgical decompression of the posterior tibial nerve was performed by complete excision of the bony mass connected to the sustentaculum tali. The excised mass was diagnosed to be osteochondroma on the histologic examination. After surgery, the pain was relieved immediately and hypoesthesia disappeared 3 months postoperatively. Physical examination and radiographic examination at 2-year follow up revealed that tarsal tunnel was completely decompressed without any evidence of complication or recurrence. CONCLUSIONS: As for tarsal tunnel syndrome secondary to the identifiable space occupying structure with a distinct neurologic symptom, we suggest complete surgical excision of the causative structure in an effort to effectively relieve symptoms and prevent recurrence.

Dimensional Changes of the Tarsal Tunnel During Foot and Ankle Positions: Anatomical Study.

The tarsal tunnel is a fibrous osseous conduit for the tibial nerve and associated tendons. It is mechanically dynamic, and foot and ankle movements appear to move and change tunnel shape. However, the effect of foot and ankle movements is not clear. The aim of this study was to measure tarsal tunnel dimensions in anatomical position of the foot and ankle and quantify its changes at different positions in cadavers. A cross-sectional study with a total of 16 cryopreserved lower extremities from cadaveric specimens were used. The foot was cut using an anatomical saw at the level of the tarsal tunnel. Measurements of the cross-sectional area (CSA), transverse diameter (TD), longitudinal diameter (LD) were taken in anatomical position and during foot and ankle movements. All the tarsal tunnel measurements were significantly modified by ankle plantar flexion (p < .05). The CSA increased by 68.97 mm2 (p < .001), the TD increased by 1.40 mm (p < .002) and the LD increased by 2.55 mm (p < .007). The TD was also significantly modified by the inversion position of the ankle, showing an increase of 0.84 mm (p < .004). The rest of the ankle positions did not produce significant changes in tarsal tunnel measurements. Foot and ankle plantar flexion position produce and increase in the CSA and the TD of the tarsal tunnel at its distal end in cadavers. This could suggest a reduction in tarsal tunnel pressure during plantar flexion.

Síndrome do aprisionamento da artéria tibial anterior bilateral pelo retináculo extensor do tornozelo: relato de caso / Bilateral anterior tibial artery entrapment by the ankle extensor retinaculum: case report

Resumo Os aprisionamentos vasculares são raros. Nos membros inferiores, geralmente são assintomáticos, mas podem causar claudicação intermitente atípica em indivíduos jovens sem fatores de risco para aterosclerose ou doenças inflamatórias. O vaso mais frequentemente acometido é a artéria poplítea, causando a síndrome do aprisionamento da artéria poplítea (SAAP), com sintomas na região dos músculos infrapatelares. Quando o desconforto ao esforço é mais distal, deve-se pensar em outros locais de aprisionamento arterial, como a artéria tibial anterior. Neste trabalho, é relatado o caso de um paciente com claudicação intermitente nos pés devido ao aprisionamento da artéria tibial anterior (AATA) bilateral, causado pelo retináculo dos músculos extensores e diagnosticado pela ultrassonografia vascular e angiotomografia durante flexão plantar. O paciente foi tratado cirurgicamente, evoluindo com melhora dos sintomas clínicos.

Abstract Vascular entrapment is rare. In the lower limbs it is generally asymptomatic, but may cause atypical intermittent claudication in young people without risk factors for atherosclerosis and inflammatory diseases. The most common type of compression involves the popliteal artery, causing symptoms in the region of the infra-patellar muscles. When discomfort is more distal, other entrapment points should be considered, such as the anterior tibial artery. This article reports the case of a patient with intermittent claudication in both feet due to extrinsic compression of the anterior tibial artery bilaterally by the extensor retinaculum of the ankle, diagnosed by vascular ultrasonography and angiotomography during plantar flexion maneuvers. The patient was treated surgically, resulting in improvement of clinical symptoms.

Tarsal Tunnel Syndrome Secondary to Accessory Musculature: A Case Report.

Tarsal tunnel syndrome (TTS) is a relatively uncommon compression neuropathy caused by impingement of the tibial nerve or one of the terminal branches. The presence of accessory musculature at the posteromedial aspect of the ankle has been identified as a rare cause of this condition. Despite the rarity of this condition, it must be considered in patients with refractory symptoms consistent with tibial nerve dysfunction. The accurate diagnosis of this condition relies heavily on a detailed history and physical examination, adequate imaging read by both surgeon and trained musculoskeletal radiologist, as well as a high level of suspicion for such pathology. In this case report, we describe a 46-year-old male with history, examination, and imaging all consistent with TTS secondary to accessory musculature. Following excision of an accessory soleus and flexor digitorum accessorius longus, as well as simultaneous tarsal tunnel release, the patient experienced full resolution of his symptoms. This highlights the importance of considering accessory musculature as a potential cause of TTS in patients presenting with tibial compression neuropathy. Levels of Evidence: Level V: Case Report.

Imaging the patient with heel pain.

Heel pain is a common presentation in primary care and affects a wide range of the population but predominantly elderly, obese and athletic patients. History and clinical assessment are paramount in the management of this condition but the presentation can confound clinicians, necessitating the use of imaging to confirm or clarify the diagnosis when there is clinical uncertainty. This article illustrates the various conditions producing heel pain to help clinicians determine the appropriate imaging modality to image the common causes of heel pain. A linked article detailing the management of heel pain is included in this issue ( https://doi.org/10.12968/hmed.2019.80.4.196 ).

Ultrasound-guided decompression surgery of the distal tarsal tunnel: a novel technique for the distal tarsal tunnel syndrome-part III.

BACKGROUND: The aim of this study was to provide a safe ultrasound-guided minimally invasive surgical approach for a distal tarsal tunnel release concerning nerve entrapments. METHODS AND RESULTS: The study was carried out on ten fresh-frozen feet. All of them have been examined by high-resolution ultrasound at the distal tarsal tunnel. The surgical approach has been marked throughout the course of the medial intermuscular septum (MIS, the lateral fascia of the abductor hallucis muscle). After the previous steps, nerve decompression was carried out through a MIS release through a 2.5 mm (± 0.5 mm) surgical portal. As a result, an effective release of the MIS has been obtained in all fresh-frozen feet. CONCLUSION: The results of our anatomic study indicate that this novel ultrasound-guided minimally invasive surgical approach for the release of the MIS might be an effective, safe and quick decompression technique treating selected patients with a distal tarsal tunnel syndrome.

Ultrasound facilitates the diagnosis of tarsal tunnel syndrome: intraneural ganglion cyst of the tibial nerve.

The tibial nerve intraneural ganglion cyst-which presents with fluid accumulated inside the nerve epineurium-is a rare etiology of tarsal tunnel syndrome. We report a case with insidious onset of numbness over his left medial ankle. Ultrasound imaging revealed that the tibial nerve was encircled by crescent-shaped anechoic substances, spanning from the distal leg to the sole. Magnetic resonance imaging disclosed a thickened tibial nerve wrapped by hyperintense materials in the tarsal tunnel. Some effusion was observed besides the tibialis posterior and flexor digitorum tendons as well. The patient underwent a surgical treatment and an intraneural ganglion cyst was confirmed. This report elaborated the clinical and imaging presentations of a tibial nerve intraneural ganglion cyst and highlighted the usefulness of ultrasound in exploring the cause of compressive neuropathy at the ankle region.

Partial anterior tunnel syndrome: a retrospective analysis of ultrasound findings in four surgically proven cases.

We present the cases of four patients (two men and two women, mean age of 48.5 years) with surgically confirmed partial anterior tarsal syndrome, diagnosed by ultrasound. All patients reported pain in the dorsal aspect of the forefoot radiating to the first intermetatarsal space. Ultrasound showed compression of the medial branch of the deep fibular nerve by the extensor hallucis brevis tendon at the level of the Lisfranc joint, associated with a hypoechoic neuroma. The ultrasound allowed a correct diagnosis to be obtained, which was not evident from clinical examination or by standard radiographs (four patients) or MRI (three patients). Surgery confirmed the sonographic findings, and all patients showed complete recovery.