Tarsal Tunnel Research Articles

Open Capsular Repair with Dermal Allograft and Tarsal Tunnel Release in the Treatment of Tarsal Tunnel Syndrome in a Young Collegiate Athlete

Tarsal tunnel syndrome is an entrapment neuropathy of the posterior tibial nerve beneath the flexor retinaculum that can be precipitated by either intrinsic or extrinsic factors. We report a unique case of a posterior medial ankle joint capsular defect with localized fluid extravasation between the flexor digitorum longus (FDL) and flexor hallucis longus (FHL) leading to symptoms consistent with tarsal tunnel syndrome in a collegiate tennis player.

ID: 221650 Successful Peripheral Nerve Stimulation for Tarsal Tunnel Syndrome - Case Report

Tarsal Tunnel Syndrome (TTS) occurs with injury to the tibial nerve due to entrapment underneath the retinaculum, fracture, previous ankle injury, or an iatrogenic etiology etc. Surgical treatment has been the mainstay of TTS, but failure of a tarsal tunnel release has been reported to be as high as 40-60% and as low as 5% [1]. The literature on therapeutic options for TTS is sparse [2,3]. We present a novel case of percutaneous peripheral nerve stimulation (PNS) of the tibial nerve to treat refractory TTS / tibial neuropathy.

Anatomical study of the medial calcaneal nerve using high-resolution ultrasound.

To determine whether high-resolution ultrasound (US) can identify the course and relations of the medial calcaneal nerve (MCN). This investigation was initially undertaken in eight cadaveric specimens and followed by a high-resolution US study in 20 healthy adult volunteers (40 nerves) by two musculoskeletal radiologists in consensus. The location and course of the MCN as well as its relationship to adjacent anatomical structures were evaluated. The MCN was consistently identified by US along its entire course. The mean cross-sectional area of the nerve was 1 mm2 (range 0.5-2). The level at which the MCN branched from the tibial nerve was variable, located a mean of 7mm (range - 7-60) proximal to the tip of the medial malleolus. At the level of the medial retromalleolar fossa, the MCN was located inside the proximal tarsal tunnel a mean of 8mm (range 0-16) posterior to the medial malleolus. More distally, the nerve was depicted in the subcutaneous tissue at the surface of the abductor hallucis fascia with a mean direct distance to the fascia of 1.5mm (range 0.4-2.8). High-resolution US can identify the MCN at the level of the medial retromalleolar fossa, as well as more distally in the subcutaneous tissue at the surface of the abductor hallucis fascia. In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of nerve compression or neuroma, and perform selective US-guided treatments. In the setting of heel pain, sonography is an attractive tool for diagnosing compression neuropathy or neuroma of the medial calcaneal nerve, and enables the radiologist to perform selective image-guided treatments such as diagnostic blocks and injections. • The MCN is a small cutaneous nerve which rises from the tibial nerve in the medial retromalleolar fossa to the medial side of the heel. • The MCN can be depicted by high-resolution ultrasound along its entire course. • In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of neuroma or nerve entrapment, and perform selective ultrasound-guided treatments such as steroid injection or tarsal tunnel release.

Prevalence of ankle accessory muscles: a cross-sectional study

Objective: Determine the prevalence of accessory muscles around the ankle of patients with ankle pain using magnetic resonance imaging (MRI) and evaluate its correlation with other foot and ankle disorders. In addition, better understand the association with accessory muscle and types of pain, mechanical due to compression forces around ankle structures or neuropathic due to mass effect around the tarsal tunnel. Methods: The MRIs obtained from 2007 to 2017 were retrospectively studied and analyzed by a radiologist specializing in foot and ankle pathologies. A total of 9,600 scans were studied after ankle pain; 31 scans had at least one accessory muscle. Results: The prevalence of symptomatic accessory muscle was 0.32% (31 feet). It was found due to mechanical pain in 45.2% of cases. It was considered an incidental finding in 32.3%. Tarsal syndrome was the main clinical presentation in 19.4%, and 16% had other causes of mechanical disorders: 10% with peroneal tendinitis, 3% with Achilles tendinopathy, and 3% with plantar fasciitis. The prevalence of accessory muscles was 35% of the flexor digitorum, 32% of the peroneus quartus, 19% of the fibulocalcaneus internus, 13% of the accessory soleus, and 6% of the tibiocalcaneus internus. Conclusion: Although rare, accessory muscles can contribute to ankle pain with various presentations that confound clinical diagnosis or even appear as incidental on MRI and should be considered in the management of ankle pain. Level of Evidence III; Therapeutic Studies; Retrospective cohort study.

Presence of Accessory Soleus Muscle in Cadaver: Case Report

Human anatomy is a variable structure. There are various rare muscle-specific accessory structures. The accessory soleus muscle (ASM) is one of them and was studied in this case report. ASM was seen during routine learning and teaching dissection lessons while dissecting the right leg of a male body. When this muscle was examined, a thick beginning with fascial connections from the soleus muscle, medially in the lower 1/3 of the leg was seen. This unipennate-shaped super numeric muscle had a 3.95 cm width, 25.82 cm length, and 0.82 cm thickness. This muscle, which is seen on radiological images, may often be confused with soft tissue tumors such as ganglion, lipoma, hemangioma, synovioma, and sarcoma, and on the pathology of the muscle may cause pain and tarsal tunnel syndrome-like effects.

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.

Imaging of Tendinous and Muscular Anatomical Variants Around the Ankle.

Tendinous and muscular anatomical variants around the ankle are usually an unexpected finding on imaging. Magnetic resonance imaging offers the best visualization of the accessory muscles; however, they can also be detected on radiography, ultrasonography, and computed tomography. Their accurate identification facilitates appropriate management of the rare symptomatic cases, mostly caused by accessory muscles in the posteromedial compartment. Symptomatic patients present with chronic ankle pain, most commonly as tarsal tunnel syndrome. The most frequently observed accessory muscle around the ankle is the peroneus tertius muscle, an accessory muscle in the anterior compartment. The tibiocalcaneus internus and peroneocalcaneus internus are uncommon; anterior fibulocalcaneus is rarely mentioned. We describe the anatomy of the accessory muscles with their anatomical relations accompanied by schematic drawings and radiologic images from clinical practice.

Patient Satisfaction with Surgery for Tarsal- and Carpal- Tunnel Syndrome - Comparative Study.

We compared the treatment satisfaction of patients who had undergone surgery for tarsal tunnel syndrome (TTS) and carpal tunnel syndrome (CTS). We enrolled 44 patients in this study; 23 were operated for CTS and 21 for TTS. All patients had received surgery under a microscope and under local anesthesia. Using the numerical rating scale (NRS) for numbness/pain (range 0-10) we compared their preoperative outcome expectations with their satisfaction with our treatment 6 months after the operation. We also recorded their pre- and postoperative EuroQol 5-dimension 5-level (EQ-5D-5L) scale for their health-related quality of life (QOL). The subjective assessment of their QOL showed that it was significantly lower in TTS- than CTS patients both pre- and postoperatively. Six months after the operation, the NRS for symptoms and the (EQ-5D-5L) scale for the QOL were significantly improved in TTS- and CTS patients; however, these scores were significantly better after CTS- than TTS surgery. Also, the postoperative NRS was significantly lower in the CTS- than the TTS patients. Our comparison of the patients' expected- and actual surgical outcome showed that the result was better than expected after CTS- and TTS surgery; in CTS patients the difference was significant. Overall, CTS- were more satisfied than TTS patients with the treatment outcome. Satisfaction with the treatment was greater after CTS- than TTS surgery. TTS- experienced less symptom relief than CTS patients although the actual- exceeded the expected outcome in patients operated for TTS.

The bifurcation and topography of the posterior tibial artery within the tarsal tunnel

PurposeThe tarsal tunnel (TT) is a fibro-osseous anatomical space coursing from the medial ankle to the medial midfoot. This tunnel acts as a passage for both tendinous and neurovascular structures, including the neurovascular bundle containing the posterior tibial artery (PTA), posterior tibial veins (PTVs) and tibial nerve (TN). Tarsal tunnel syndrome (TTS) is the entrapment neuropathy that describes the compression and irritation of the TN within this space. Iatrogenic injury to the PTA plays a significant role in both the onset and exacerbation of TTS symptoms. The current study aims to produce a method to allow clinicians and surgeons to easily and accurately predict the bifurcation of the PTA, to avoid iatrogenic injury during treatment of TTS.MethodsFifteen embalmed cadaveric lower limbs were dissected at the medial ankle region to expose the TT. Various measurements regarding the location of the PTA within the TT were recorded and multiple linear regression analysis performed using RStudio.ResultsAnalysis provided a clear correlation (p < 0.05) between the length of the foot (MH), length of hind-foot (MC) and location of bifurcation of the PTA (MB). Using these measurements, this study developed an equation (MB = 0.3*MH + 0.37*MC – 28.24 mm) to predict the location of bifurcation of the PTA within a 23° arc inferior to the medial malleolus.ConclusionsThis study successfully developed a method whereby clinicians and surgeons can easily and accurately predict the bifurcation of the PTA, to avoid iatrogenic injury that would previously lead to an exacerbation of TTS symptoms.

Injection of the Abductor Hallucis Muscle in the Diagnosis and Treatment of Distal Tarsal Tunnel Syndrome.

Tarsal tunnel syndrome (TTS) can be divided into proximal TTS and distal TTS (DTTS). Research on methods to differentiate these two syndromes is sparse. A simple test and treatment is described as an adjunct to assist with diagnosing and providing treatment for DTTS. The suggested test and treatment is an injection of lidocaine mixed with dexamethasone administered into the abductor hallucis muscle at the site of entrapment of the distal branches of the tibial nerve. This treatment was studied with a retrospective medical record review in 44 patients with clinical suspicion of DTTS. The lidocaine injection test and treatment (LITT) was positive in 84% of patients. Of patients available for follow-up evaluation (35), 11% of those with a positive LITT test (four) had complete lasting symptom relief. One-quarter of patients with initial complete symptom relief at LITT administration (four of 16) maintained this level of symptom relief at follow-up. Thirty-seven percent of patients evaluated at follow-up (13 of 35) who had a positive response to the LITT experienced partial or complete symptom relief. No association was found between level of symptom relief maintenance and the immediate level of symptom relief (Fisher exact test = 0.751; P = .797). The results showed no difference in the distribution of immediate symptom relief by sex (Fisher exact test = 1.048; P = .653). The LITT is a simple, safe, invasive method to help diagnose and treat DTTS, and it provides an additional method to assist with differentiating DTTS from proximal TTS. The study also provides additional evidence that DTTS has a myofascial etiology. The proposed mechanism of action of the LITT suggests a new paradigm in diagnosing muscle-related nerve entrapments that may lead to nonsurgical treatments or less invasive surgical interventions for DTTS.

High Prevalence of Tarsal Tunnel Syndrome in Patients Diagnosed with Fibromyalgia Syndrome

Abstract Objective To evaluate foot function and prevalence of tarsal tunnel syndrome in patients diagnosed with fibromyalgia syndrome as compared with healthy individuals. Methods This prospective study included 111 participants, including 63 female patients with fibromyalgia (mean age: 46.17±6.64 years) and 48 female healthy controls (mean age: 46.16±9.38 years) who met the selection criteria. The participants were evaluated for Tinel’s sign and asked about the presence of foot pain and paraesthesia in both groups. In addition, the participants were assessed using the Fibromyalgia Impact Questionnaire and Foot Function Index (FFI) for functionality. Bilateral electrophysiological studies of the tibial, peroneal, sural, medial and lateral plantar nerves were performed. Results Tarsal tunnel syndrome was present in 20 extremities of the patients with fibromyalgia (15.9%) and four extremities of the controls (4.2%)(p=0.005). Paraesthesia was observed in 56 extremities in the fibromyalgia group (44.4%) and 10 extremities in the control group (10.4%)(p&lt;0.001). Tinel’s sign was positive in 69 extremities (54.8%) in the fibromyalgia group and 17 in the control group (17.7%)(p&lt;0.001). The total number of painful feet was 123 (97.6%) in the fibromyalgia group and 22 (22.9%) in the control group (p&lt;0.001). The mean total FFI was 66.26±60.80 for the right foot and 66.28±64.12 for the left foot in the FMS group; in the control group, it was 16.02±31.01 and 16.87±34.14, respectively. Both values exhibited a statistically significant difference between the two groups (p&lt;0.001) Conclusion In patients with fibromyalgia syndrome, paraesthesia and foot pain may be seen more frequently. Therefore, electrophysiological evaluation of the lower extremities may be recommended in these patients.

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.

Midterm Clinical and Radiographic Outcomes of the Calcaneal Z-Osteotomy for the Correction of Cavovarus Foot.

The Malerba calcaneal Z-osteotomy is an operative procedure to treat the hindfoot varus component of adult cavovarus deformity. Basic science studies support the corrective ability of this osteotomy. However, there have been no published midterm clinical and radiographic results. The purpose of this article is to describe the radiographic and clinical improvement in a series of patients treated with this osteotomy. A retrospective chart review identified 14 feet in 12 patients from January 2013 to August 2018 who met minimal follow-up criteria. Preoperative visual analog scale (VAS) scores, Foot Function Index (FFI) scores, and American Orthopaedic Foot & Ankle Society (AOFAS) scores were compared with postoperative scores. Preoperative Meary angle, calcaneal pitch, and hindfoot alignment were also compared with postoperative measurements. Complications and radiographic union were recorded. At a mean of 80 months, VAS, FFI, and AOFAS scores improved from 7.86 to 1.64, 57.78% to 18.11%, and 39.57 to 80.71, respectively (all P < .001). At a mean of 15 months, Meary angle, calcaneal pitch, and hindfoot alignment improved from 11.14 to 6.64 degrees (P < .001), 30.93 to 27.43 degrees (P = .005), and 19.83 degrees varus to 8.50 degrees varus (P < .001). There was 1 nonunion and 1 postoperative sural nerve neuralgia, but both patients ultimately did well clinically. There were no instances of postoperative tarsal tunnel syndrome. All patients stated that they would have the procedure done again. The calcaneal Z-osteotomy is an effective method to treat adult hindfoot cavovarus deformity. All patients had good clinical outcomes with minimal complications. Level IV, case series.

Tarsal tunnel syndrome – a disease ignored by doctors and totally unknown for the patients

Tarsal tunnel syndrome (TTS), or tibial nerve compression at the internal malleolus level, is a frequently missed disease among clinicians, although it can be found in diabetic pa­tients (almost half of them will develop peripheral neu­ro­pa­thy and related complications) and in non-diabetic pa­tients due to the existence of tumors and anatomical ac­ces­sory elments. The aim of this paper is to increase the le­vel of awareness regarding the TTS diagnostic tools and treat­ments among doctors. The main source of literature re­view was PubMed database and the author’s per­so­nal ex­­pe­­rience. Although it is considered a rare di­sease, for sure underdiagnosed, left without treatment, TTS will lead to foot sensitive and motor deficits with dra­ma­tic ef­fects on patients quality of life and survival. Pa­tient’s his­to­ry, cli­ni­cal examination (positive Tinel sign, ob­jec­tive test­ing of in­creased sensibility threshold) and pa­ra­cli­ni­cal exa­mi­na­tion (soft tissue ultrasonography and ner­vous conduction stu­dies) highlight the diagnostic. The con­ser­va­tive and mi­ni­mally invasive therapeutic methods are effi­cient, but limited in time, the surgical solution – tarsal tun­nel de­com­pre­sion – being still the elective procedure, even in cri­ti­cal peri­pheral neu­ro­pa­thy.

The role of ultrasound-guided perineural injection of the tibial nerve with a sub-anesthetic dosage of lidocaine for the diagnosis of tarsal tunnel syndrome.

Tarsal tunnel syndrome (TTS) involves entrapment of the tibial nerve at the medial ankle beneath the flexor retinaculum and its branches, the medial and lateral plantar nerves, as they course through the porta pedis formed by the deep fascia of the abductor hallucis muscle. TTS is likely underdiagnosed, because diagnosis is based on clinical evaluation and history of present illness. The ultrasound-guided lidocaine infiltration test (USLIT) is a simple approach that may aid in the diagnosis of TTS and predict the response to neurolysis of the tibial nerve and its branches. Traditional electrophysiological testing cannot confirm the diagnosis and only adds to other findings. We performed a prospective study of 61 patients (23 men and 38 women) with a mean age of 51 (29-78) years who were diagnosed with idiopathic TTS using the ultrasound guided near-nerve needle sensory technique (USG-NNNS). Patients subsequently underwent USLIT of the tibial nerve to assess the effect on pain reduction and neurophysiological changes. USLIT led to an improvement in symptoms and nerve conduction velocity. The objective improvement in nerve conduction velocity can be used to document the pre-operative functional capacity of the nerve. USLIT may also be used as a possible quantitative indicator of whether the nerve has the potential to improve in neurophysiological terms and ultimately inform prognosis after surgical decompression. USLIT is a simple technique with potential predictive value that can help the clinician to confirm the diagnosis of TTS before surgical decompression.

An anatomical approach to the tarsal tunnel syndrome: what can ankle’s medial side anatomy reveal to us?

BackgroundThe heel is a complex anatomical region and is very often the source of pain complaints. The medial heel contains a number of structures, capable of compressing the main nerves of the region and knowing its anatomical topography is mandatory. The purpose of this work is to evaluate if tibial nerve (TN) and its main branches relate to the main anatomical landmarks of the ankle’s medial side and if so, do they have a regular path after emerging from TN.MethodsThe distal part of the legs, ankles and feet of 12 Thiel embalmed cadavers were dissected. The pattern of the branches of the TN was registered and the measurements were performed according to the Dellon–McKinnon malleolar-calcaneal line (DML) and the Heimkes Triangle (HT).ResultsThe TN divided proximal to DML in 87.5%, on top of the DML in 12,5% and distal in none of the feet. The Baxter’s nerve (BN) originated proximally in 50%, on top of the DML in 12,5% and distally in 37.5% of the cases. There was a strong and significant correlation between the length of DML and the distance from the center of the medial malleolus (MM) to the lateral plantar nerve (LPN), medial plantar (MPN) nerve, BN and Medial Calcaneal Nerve (MCN) (ρ: 0.910, 0.866, 0.970 and 0.762 respectively, p < 0.001).ConclusionsIn our sample the TN divides distal to DML in none of the cases. We also report a strong association between ankle size and the distribution of the MPN, LPN, BN and MCN. We hypothesize that location of these branches on the medial side of the ankle could be more predictable if we take into consideration the distance between the MM and the medial process of the calcaneal tuberosity.

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.

Imaging of accessory soleus muscle: A case report with review of the literature

The accessory soleus muscle is an uncommon anatomical variant. It usually manifests as ankle pain and swelling or as an asymptomatic soft-tissue mass along the posterior and medial aspect of the ankle. In a few cases, it is sometimes misdiagnosed as a mesenchymal lesion. The idea of this case report was to highlight the existence of accessory soleus muscle mistaken as a mesenchymal tumor on fine needle aspiration cytology (FNAC). A 32-year-old male patient presented to the orthopedics department with a soft swelling in the distal one-third of the left leg posterior to the medial malleolus. The patient noticed this swelling about 5 years back. The swelling was non-tender and non-pulsatile. Before the imaging, FNAC from the swelling was done which raised suspicion of a mesenchymal lesion. He was referred to the radiodiagnosis department for imaging evaluation of the swelling. A radiological diagnosis of accessory soleus muscle was made; ruling out the possibility of a mesenchymal tumor. This accessory muscle is a less common congenital anatomic variant rather than a soft-tissue mass lesion. The characteristic imaging appearance and location of this muscle give a definite diagnosis. Further, it highlights this rare variation pertaining to its calcaneal insertion and relation with the flexor retinaculum and tarsal tunnel, which should be kept in mind by radiologists.

The effects of tibial nerve mobilization in patients with tarsal tunnel syndrome: A randomized controlled trial

In tarsal tunnel syndrome (TTS), the nerve mobilization, one of the conservative treatment methods, aims to relieve abnormal nerve tension with appropriate movements of the nerve tissue. The aim of this study was to investigate the effect of tibial nerve mobilization in addition to home exercise on the tibial nerve area in patients diagnosed with TTS. The study included 40 participants, including 20 cases in the intervention group (IG) and 20 cases in the control group (CG). IG received tibial nerve mobilization and a home exercise program for and foot-ankle joint. Participants in the control group had only a home exercise program for the foot-ankle joint. Primary outcome measures were tibial nerve diameter and Tinel's sign measurements. Secondary outcome measures were pain intensity, neuropathic pain status (NPQ) and foot functional index (FFI). The positive Tinel's sign incidence was lower in favour of IG (Odds ratio:0.11 95% CI: 0.03 to 0.46). Between-group comparisons revealed a significant difference in pain intensity (Mean difference: 1.45; 95% CI: 0.69 to 2.20), NPQ (Mean difference: 0.70; 95% CI: 0.36 to 1.03), pain subscale (Mean difference: 10.0; 95% CI: 4.33 to 15.66) and total score of FFI (Mean difference: 20.60; 95% CI: 0.53 to 40.66) in favour of IG. There was no reported adverse events. This study showed that the addition of tibial nerve mobilization to home exercise program might improve symptoms, especially pain and functionality in patients with TTS. Further studies with large sample sizes are need to support these results.

Unusual entrapment symptomatology treated in 115 cases by neurolysis of the common fibular nerve at the fibular head combined with neurolysis of the posterior tibial nerve at the tarsal tunnel

IntroductionEntrapment of the common fibular nerve (CFN) at the head of the fibula and entrapment of the posterior tibial nerve (PTN) at the tarsal tunnel are the most common nerve entrapment syndromes in the lower limb. Our aim was to study the results of combined neurolysis of the CFN and PTN for chronic lower limb pain. We hypothesized that combined neurolysis allowed a reduction of this chronic pain. Material and methodThis bi-centric retrospective study took place from January 2015 to November 2018, with a single senior surgeon. The inclusion criteria were all patients operated on for an idiopathic entrapment syndrome with neurolysis of the PTN at the tarsal tunnel, combined with neurolysis of the CFN at the head of the fibula. The primary endpoint was the pain evolution assessed on a numerical analogue scale (NAS) preoperatively and postoperatively on D+21, and at the last follow-up. The secondary endpoint was to determine the prognostic factors on the clinical outcome of neurolysis. ResultsOne hundred and fifteen neurolysis were included, comprising 64 women and 38 men with a mean age of 57±17.6 years. The preoperative pain (NAS0) was evaluated at 6±2.4 points. At D+21 postoperatively, there was a significant reduction in pain (NASD+21: 3±2.6 points, p<0.01). Similarly, at the last follow-up (with a mean follow-up of 37±8.4 months), there was a significant reduction in pain (NASLFU: 2±2.5, p<0.01). A history of systemic inflammatory disease was the only factor associated with a less significant decrease in pain at D+21, according to a multivariate analysis (p<0.01). There were 14 complications (12%) not requiring revision surgery. ConclusionThis study is the first to demonstrate the efficacy of combined neurolysis of the CFN at the head of the fibula and the PTN at the tarsal tunnel, in the treatment of idiopathic nerve entrapment syndrome of the lower limb. Level of evidenceIV; Retrospective comparative study.