Outcomes of Common Peroneal Nerve Decompression.

PURPOSE: Common peroneal nerve (CPN) neuropathy is the most common lower extremity mononeuropathy. When delayed or no recovery from CPN neuropathy is suspected, surgical CPN decompression (CPND) is considered to relieve symptoms. This study aimed to evaluate patient outcomes post-CPND performed by a single surgeon at a tertiary medical center. METHODS: Patient outcomes after CPND performed by a single surgeon were reviewed. Motor, sensation, and pain scores post-CPND were assessed in 47 of the 46 patients. Patient demographics, including age, concomitant morbidities, time from injury to surgery, and body mass index (BMI), were also analyzed for correlations with outcomes after CPND by logistic regression. RESULTS: 29/34 patients with impaired motor function improved by at least one motor grade, 19/42 with altered sensation reported restored normal sensation, and 31/37 reported improved pain after CPND. No correlation of patient demographic factors with motor or pain improvement after CPND was observed. However, a BMI greater than 29.15 and a time between injury and surgery exceeding 506 days were associated with lower odds of reporting restored sensation. CONCLUSIONS: Operative decompression of CPN neuropathy improves objective motor scores and subjective sensation and pain scores.

Anterolateral and accessory anterolateral portals are safe to avoid subcutaneous nerve injury during subtalar arthroscopy-Definition of safe zones for standard lateral portals.

PURPOSE: Injury to the superficial peroneal nerve (SPN) or the sural nerve (SN) is a common complication in subtalar arthroscopy. The purpose of this anatomical study was to evaluate the distance to surrounding subcutaneous nerves in the vicinity of three standard arthroscopic portals for subtalar joint arthroscopy and through actual portal placement for arthroscopic procedures, in order to define anatomical safe zones. METHODS: Forty paired fresh-frozen foot-and-ankle specimens were used. Subtalar arthroscopy using a three-portal technique (anterolateral [AL], posterolateral [PL] and accessory anterolateral [AAL] portals) was performed. After completion of subtalar arthroscopy, the portals were marked, and all surrounding subcutaneous nerves, that is, the branches of the SPN and SN, were dissected. The distance of the nearest nerve at the level of the respective portal was measured and potential injury was recorded. RESULTS: The nearest nerve at the level of the AL portal was the intermediate dorsal cutaneous nerve at a mean of 15.4 ± 5.1 mm medial to the portal. The nearest nerve at the level of the AAL portal was the lateral dorsal cutaneous nerve at a mean of 17.7 ± 4.8 mm, being lateral to the portal. The nearest nerve at the level of the PL portal was the SN at a mean of 6.7 ± 4.7 mm anterior to the portal. Based on the measurements, safe zones were defined. CONCLUSIONS: Placement of the AL and AAL portals in subtalar arthroscopy is saved using standard anatomical landmarks and a thorough surgical technique. At the level of the PL portal, the SN is the most endangered structure in subtalar arthroscopy. Surgeons should be aware of the proximity of the SN to the PL portal and take the utmost care during portal placement and instrument insertion to avoid iatrogenic injury. The risk of nerve damage during portal placement may be reduced when positioning the portals in the defined safe zones. LEVEL OF EVIDENCE: Not applicable.

Effects of low-frequency pulsed electrical stimulation at the common peroneal nerve on chronic refractory wounds of the lower limb: A randomized controlled trial.

Background and aims: Electrical stimulation (ES) has been shown to substantially enhance the quality of life by alleviating pain in patients with chronic wounds. This study aimed to observe the effects of low-frequency pulsed wearable ES at the common peroneal nerve on chronic refractory wounds of the lower limb. Methods: Forty-eight participants were randomly divided into control group (n = 24) and treatment group (n = 24) in this study. The control group received standard wound care (SWC) exclusively, whereas the treatment group was administered both SWC and the wearable low-frequency ES targeting the common peroneal nerve. Measurements of wound area, pain intensity, wound status, and quality of life scores were systematically recorded both before and after 4 weeks treatment. Results: After 4 weeks of intervention, the percentage area reduction was significantly higher in the treatment group compared to the control group (Z = -3.9, p < 0.001), and the healing rate of the treatment group was significantly higher than that of the control group (33% vs. 4%). Moreover, the visual Analog Scale for Pain score (ß = -0.65, p = 0.019), the Bates-Jensen Wound Assessment Tool score (p < 0.05), and the questionnaire on quality of life with chronic wounds (Wound-Qol) score (ß = -4.23, p = 0.003) were significantly decreased in the patients in the treatment group compared to the control group. Conclusion: The wearable low-frequency pulsed ES at the common peroneal nerve for the treatment of chronic refractory wounds showed significant improvement and were far superior compared to SWC. Future research should broaden its scope to include a diverse range of wound types and benefit from collaboration across multiple research centers.

Proximal Fibulectomy for Giant Cell Tumours: What Works!

Background: Giant cell tumor of bone (GCTB) is the most common primary tumor of proximal fibula. Because of its close proximity to vascular structures, common peroneal nerve (CPN) and attachment of lateral collateral ligament (LCL), proximal fibulectomy poses unique challenges. We analyzed oncological and functional outcome of patients who underwent proximal fibulectomy for GCTB of proximal fibula. Material and methods: Between January 2006 and December 2020, 23 patients underwent proximal fibulectomy for GCTB of proximal fibula, four were recurrent tumors. Mean resection length was 9 cm (5 to 15 cm). The LCL and biceps tendon were not reconstructed in 22 cases. The common peroneal nerve was sacrificed in seven patients including three recurrent cases. Functional status was assessed using the Musculoskeletal Tumour Society (MSTS) scoring system. Results: There were two vascular complications and one infection. With 4 patients lost to follow up, mean follow up was 90 months (12 to 197). No patient had local or distant recurrence. Mean MSTS score was 26 (21 to 30). Eleven of 23 patients (48%) had loss of common peroneal nerve function with poorer functional outcome. No patient had symptoms suggestive of knee instability. Conclusion: Proximal fibulectomy is oncologically safe. Reconstruction of the LCL attachment is not mandatory and patients do not have symptomatic knee instability. Functional outcomes are compromised after sacrifice of common peroneal nerve and may be potentially improved with tendon transfers at index surgery.

The Rare Large Common Peroneal Nerve's Schwannoma-A Case Report and Literature Review.

Schwannoma in the popliteal fossa is still rare, often diagnosed late because it grows slowly and has no symptoms. It is often misdiagnosed with connective tissue tumors or with neurological disorders originating in the spine or disorders of the peroneal nerve. Schwannoma within the common peroneal nerve is still rare in the popliteal fossa, with most tumor sizes around 2 cm in diameter due to their smaller size of nerve but can cause neurologic disturbance, especially when it is large. And over a long time, it can cause serious complaints like neurological deficits and make surgery difficult by leaving greater sequelae. There is no data yet showing the incidence of schwannoma in the common peroneal nerve. In this case, a 36-year-old woman, for 5 years, feels soreness in the popliteal fossa and pain in the right instep, suspected that a nerve was pinched, due to an abnormality in the spine. As time went on, there was a lump in the fold of the right knee, suspected to be a Baker's cyst. As time went by, the complaint was burning pain in the right instep to the lateral ankle and distal right lower leg, disturbing sleep. Tinel's sign was positive. The right instep has hypoesthesia and a slight drop in the foot. On radiological examination of the right knee, a circumferential mass appeared, measuring 5 cm × 4 cm. The diagnosis is suspicious for a common peroneal nerve tumor. The encapsulated operation to remove the tumor was carried out with a size measuring 5 cm × 4.5 cm × 4 cm. The histopathological examination showed schwannoma. After surgery, the pain disappeared, hypoesthesia and a slight drop in the foot underwent physiotherapy, and stimulation with the result gradually improved. A thorough early examination includes correct and systematic anamnesis, physical examination, and neurological evaluation such as paraesthesia, hypoesthesia, and Tinel's sign; also, additional examinations, such as radiographic, ultrasound, and MRI, are needed for early detection of schwannoma so that delays in diagnosis and surgery can be avoided to prevent neurological deficits.

A Rare Case of Transepiphyseal Distal Femur Fracture Dislocation With Delayed Recovery of a Common Peroneal Nerve Injury.

The aim of this study is to bring attention to a unique case and our approach to treatment in this context. We describe a case of an 11-year-old male who presented to us with an injury to his left knee following trauma with pain, swelling, shortening and deformity for one day. An X-ray revealed a transepiphyseal fracture dislocation of the left distal femur (Salter-Harris type 1 injury) and neurovascular examination was conclusive of foot drop which pointed towards injury to common peroneal nerve (CPN). The patient was taken up for closed reduction with percutaneous pinning under mobile C-arm guidance. The fracture was reduced and fixed with two cross K-wires and immobilized with the above knee anterior-posterior slab for six weeks. The wires were removed after six weeks but there was no improvement in the dorsiflexion of the left ankle. An electromyography (EMG) and nerve conduction velocity (NCV) study test was performed after 12 weeks which showed decreased amplitude and prolonged latency in the left CPN with early denervation of the muscles supplied by the left CPN. Fifteen weeks of follow-up showed complete recovery in the dorsiflexion of the left ankle with a slight lag in the extension of the left great toe making this an unusually delayed recovery of CPN palsy following a distal femur transepiphyseal fracture.

Risk of Nerve Injury Following Peroneus Longus Harvest is Very Low: A Prospective Cohort of 600 Patients.

Background: Peroneus longus (PL) graft harvest has gained popularity in recent years for a variety of ligament surgeries. One of the common apprehensions regarding its more widespread usage has been the risk of injury to the common peroneal nerve or the sural nerve during graft harvest. The purpose of the current study is to assess the rate of injury to the peroneal and sural nerve following PL harvest using our technique in a large cohort of patients. Materials and Methods: A prospective cohort of 600 consecutive patients undergoing PLG harvest over a period from January 2022 to December 2022 at a single tertiary referral centre were included for analysis. Patients had baseline screening of nerve function prior to surgery and were regularly followed up at 3 weeks, 6 weeks, 3 months and 6 months post-harvest. Grouped variables for the sural and peroneal nerve were completed and analysis was carried out using Cochrane's Q test and McNemar's test. Results: We found that only 0.01% of patients had any nerve complications at 6 months follow-up, and three times more patients had sural nerve complaints than peroneal nerve complaints at the end of the 6 months follow-up. Conclusion: Peroneus longus harvest is a safe and reproducible technique with low complication rate. The rate of nerve complications post-harvest is grossly overestimated in the literature secondary to low-powered and low evidence studies. We believe that using our safe surgical technique for PL harvest with respect to surface landmarks allows for PL harvest with a low nerve complication rate.

Low Back Pain Caused by Traction Peripheral Neuropathy Due to Chronic Ankle Instability: Three Clinical Cases.

Non-specific low back pain without identifiable causes on imaging is a common and frustrating problem for both patients and physicians. While proximal symptoms such as shoulder pain from distal upper extremity neuropathies such as carpal tunnel syndrome are well-known, peripheral neuropathy of the foot or ankle is rarely considered in the differential diagnosis for low back pain. This study aims to highlight the potential link between chronic ankle instability (CAI) and low back pain. We present three cases: a 32-year-old woman with chronic low back pain for over 10 years, a 59-year-old woman with transient low back pain after long drives, and a 42-year-old woman with acute low back pain while gardening. All patients had normal imaging studies but exhibited CAI on examination. Diagnostic modalities included the ankle anterior drawer test, application of ankle brace, superficial peroneal nerve (SPN) blocks, and assessment of the active straight leg raise (aSLR) angle. In the first case, low back pain disappeared after SPN neurolysis and ankle ligament reconstruction. The second case showed significant improvement in aSLR and pain reduction with SPN block and ankle brace. The third case experienced substantial pain relief with the use of an ankle brace. These findings suggest that addressing ankle instability and associated traction neuropathy can significantly alleviate low back pain symptoms. CAI may be an underrecognized cause of non-specific low back pain. Interventions such as ankle brace, SPN blocks, SPN decompression, and ankle ligament reconstruction can be effective for diagnosis and treatment, potentially offering relief for patients with chronic low back pain.

Unilateral Compressive Peroneal Neuropathy in Intensive Care Settings During the COVID-19 Pandemic: A Series of Three Cases.

Peroneal nerve entrapment, typically associated with behaviors like cross-legged sitting or squatting, can also occur from extended periods of lying down where the lower limbs usually assume a position of hip external rotation and knee flexion. In such positions, the fibular head's prominence can exert sustained pressure on the peroneal nerve. We report three cases of unilateral peroneal neuropathy in intensive care unit (ICU) patients during the coronavirus disease (COVID-19) pandemic, highlighting the possible role of prolonged supine or lateral decubitus positions in the development of this condition. Electrophysiological studies confirmed peroneal nerve palsy in all cases, with two patients achieving full recovery, while the third required a permanent ankle foot orthosis for mobility due to a lack of neurological recovery. The COVID-19 pandemic has challenged ideal nursing care, including in ICU settings, leading to suboptimal nursing care standards and compromised frequent positioning regimes.

Unravelling the Anatomy of the Anterior Tarsal Tunnel and Its Clinical Implications.

BACKGROUND: Anterior tarsal tunnel (ATT) syndrome is caused by the compression of the deep fibular nerve (DFN) within the ATT beneath the inferior extensor retinaculum, bounded by the tendons of the extensor hallucis longus (EHL) and extensor digitorum longus (EDL). Compression may result from direct trauma, repetitive mechanical irritation, and thrombosis of the dorsalis pedis artery. Injury to the contents of ATT could occur during ankle arthroscopy. Therefore, this study was undertaken to provide a detailed description of the anatomy of the ATT and its clinical implications. MATERIALS AND METHODS: Ten formalin-fixed cadavers were utilized for the study. The ATT was identified between the tendons of the EHL and EDL. The length at the medial and lateral boundaries and the width at the proximal end, middle, and distal end of the ATT were measured using a digital Vernier calliper. RESULT: The mean length of the medial border of the tunnel was 31.42±8.44 mm, while the lateral border was 20.39±4.39 mm. The width of the ATT increased from the proximal to the distal end. DFN was related to the DPA laterally in 15 limbs and medially in five limbs within the tunnel. CONCLUSION: The present study not only describes the intricate anatomy of the ATT but also describes the patterns of DFN and DPA within the tunnel. Understanding the anatomy of ATT is crucial, as it paves the way for safe and efficient surgical interventions, thereby significantly reducing the risk of neurovascular damage during surgical procedures.

Core outcomes in nerve surgery: development of a core outcome set for common peroneal (fibular) neuropathy.

OBJECTIVE: Common peroneal (fibular) neuropathy is the most common mononeuropathy of the lower extremity. Despite this, there are surprisingly few studies on the topic, and a knowledge gap remains in the literature. As one attempts to address this knowledge gap, a core outcome set (COS) is needed to guide the planning phases of future studies to allow synthesis and comparability of these studies. The objective of this study was to develop the COS-common peroneal neuropathy (CoPe) using a modified Delphi approach. METHODS: A 5-stage approach was used to develop the COS-CoPe: 1) stage 1, consortium development; 2) stage 2, a literature review to identify potential outcome measures; 3) stage 3, a Delphi survey to develop consensus on outcomes for inclusion; 4) stage 4, a Delphi survey to develop definitions; and 5) stage 5, a consensus meeting to finalize COS and definitions. The study followed the COS-STAndards for Development (COS-STAD) recommendations. RESULTS: The Core Outcomes in Nerve Surgery (COINS) Consortium comprised 23 participants, all neurological surgeons, representing 13 countries. The final COS-CoPe consisted of 31 data points/outcomes covering domains of demographics, diagnostics, patient-reported outcomes, motor/sensory outcomes, and complications. Appropriate instruments, methods of testing, and definitions were set. The consensus minimum duration of follow-up was 12 months. The consensus optimal time points for assessment were preoperatively and 3, 6, 12, and 24 months postoperatively. CONCLUSIONS: The COINS Consortium developed a consensus COS and provided definitions, methods of implementation, and time points for assessment. The COS-CoPe should serve as a minimum set of data that should be collected in all future neurosurgical studies on common peroneal neuropathy. Incorporation of this COS should help improve consistency in reporting, data synthesis, and comparability, and should minimize outcome reporting bias.

Ultrasound evaluation and grading of neuromuscular disease in lower extremities among diabetic patients.

OBJECTIVE: To explore the clinical utility of ultrasound in evaluating and grading neuromuscular diseases in the lower extremities of patients with diabetes mellitus. METHODS: A total of 126 inpatients from the Department of Diabetes at Zhangzhou Affiliated Hospital of Fujian Medical University, China, were recruited from June 2020 to December 2022. The cohort included 69 patients with type 2 diabetes mellitus (T2DM) and diabetic peripheral neuropathy (DPN group) and 57 patients with T2DM but without DPN (non-DPN group). Additionally, 80 healthy controls were included. High-frequency ultrasound was used to scan the common peroneal, sural, and tibial nerves, measuring their transverse (D1) and anteroposterior (D2) diameters, and calculating the cross-sectional area (CSA). Changes in the internal echo of the extensor digitorum brevis (EDB) muscle, including maximum thickness and CSA, were also recorded. The DPN group was further subdivided based on disease duration to assess ultrasonic changes over time and the statistical significance of these variations. RESULTS: Ultrasonic changes such as uneven internal echo reduction, ill-defined epineurial boundaries, and obscured cribriform structures were most prevalent in the DPN group. Significant differences in ultrasound parameters (D1, D2, CSA) were observed among the groups (all P<0.05), with the most pronounced changes in the DPN group. In patients with a disease duration of over 15 years, a significant increase in CSA of lower extremity nerves and a decrease in CSA of the EDB were noted compared to those in the 5-10 years subgroup (19.89±0.98 vs 19.00±0.94; 5.25±0.74 vs 5.93±0.94; all P<0.05). CONCLUSIONS: High-frequency ultrasound provides a valuable imaging basis for diagnosing and monitoring DPN, demonstrating significant changes in nerve and muscle parameters among diabetic patients.

Extensor Retinaculum Syndrome of the Ankle: An Adult Case Series.

Background: Extensor retinaculum syndrome (ERS) is a relatively rarely diagnosed compartment syndrome-like entity caused by elevated pressures in the tissues deep to the superior extensor retinaculum (SER). ERS is identified as out-of-proportion anterior ankle pain, pain with passive toe plantarflexion, elevated SER pressures (>40 mm Hg), and ultimately toe extension weakness and first web space numbness. Although previously described in a pediatric population, this case series is the first to our knowledge in an adult population. Methods: Seven nonconsecutive cases over 18 years from 2 surgeons are reported who underwent complete SER release for ERS either through the direct lateral approach to the fibula or the anterolateral approach to the distal tibia. All were associated with traumatic injuries including 3 bimalleolar ankle fractures, 3 tibial pilon fractures, and 1 distal tibial/fibular shaft fracture. All patients developed writhing anterior ankle pain worsened with passive toe plantarflexion. SER compartment pressures ranged from 50 to >135 mm Hg. Five cases displayed decreased first web space sensation. Results: The diminished or absent first web space sensation uniformly improved post-release. Complications included 1 patient with complex regional pain syndrome type 1, 1 patient required hardware removal, and 2 had persistent but improved first web space sensation changes. Conclusion: Clinical suspicion for possible ERS should arise after distal tibial/fibular fractures when the excruciating pain localizes to the ankle instead of the classic anterior leg muscle bellies. If pain is worsened with passive toe plantarflexion, this diagnosis should be considered. Recommended treatment involves complete release of the SER anywhere on the anterior surface between the tibia and fibula depending on the approach needed for fixation of the associated fracture. Level of Evidence: Level IV, case series.

A Rare Case of a Schwannoma on the Foot - Case Report.

A Schwannoma is an infrequent lesion. This tumor derives from the myelin sheath of the peripheral nerves; in most cases, it is benign and rarely presents in the foot and ankle region. Patients affected by this type of pathology are usually asymptomatic. Still, they sometimes have sensory or motor neurologic symptoms if the tumor is large enough to cause direct or indirect compression of the affected nerve. A 55-year-old male patient presented to our department with non-traumatic swelling and pain in the lateral aspect of the right foot and leg. A magnetic resonance imaging (MRI) scan of the right leg revealed a well-circumscribed lesion, measuring 2,5 by 1 cm, showing hypointensity on T1 sequences and hyperintensity on T2, compatible with a superficial peroneal nerve sheath cells tumor. Surgical excision of the lesion was performed, and the histopathological examination confirmed the initial suspicion-Schwannoma of the superficial peroneal nerve. The postoperative period was uneventful, with progressive improvement of pain and complete functional recovery without neurological deficits. Rigorous clinical examination associated to MRI scans allow adequate diagnosis as well as the exclusion of other pathologies with similar clinical presentation. Thus, the surgeon has to be aware of all the data for an effective diagnosis and treatment in this type of rare pathology that cannot be neglected.

Erosion of Stumble Correction Evoked with Superficial Peroneal Nerve Stimulation in Older Adults during Walking.

In healthy young adults, electrical stimulation of the superficial peroneal cutaneous nerve (SPn) innervating the dorsum of the foot has been shown to elicit functionally relevant reflexes during walking that are similar to those evoked by mechanical perturbation to the dorsum of the foot during walking and are referred to as stumble corrective (obstacle avoidance) responses. Though age-related differences in reflexes induced by mechanical perturbation have been studied, toe clearance has not been measured. Further, age-related differences in reflexes evoked by electrical stimulation of SPn have yet to be determined. Thus, the purpose of this study was to characterize age-related differences between healthy young adults and older adults with no history of falls in stumble correction responses evoked by electrical stimulation of the SPn at the ankle during walking. Toe clearance relative to the walking surface along with joint displacement and angular velocity at the ankle and knee and EMG of the tibialis anterior, medial gastrocnemius, biceps femoris and vastus lateralis were measured. The combined background and reflex toe clearance was reduced in the older adults compared with the young in mid-early swing (p = 0.011). These age-related differences likely increase fall risk in the older adult cohort. Further, age-related changes were seen in joint kinematics and EMG in older adults compared with the young such as decreased amplitude of the plantarflexion reflex in early swing in older adults (p < 0.05). These altered reflexes reflect the degradation of the stumble corrective response in older adults.

Palsy of Both the Tibial Nerve and Common Peroneal Nerve Caused by a Ganglion Cyst in the Popliteal Area.

A ganglion cyst is a benign mass consisting of high-viscosity mucinous fluid. It can originate from the sheath of a tendon, peripheral nerve, or joint capsule. Compressive neuropathy caused by a ganglion cyst is rarely reported, with the majority of documented cases involving peroneal nerve palsy. To date, cases demonstrating both peroneal and tibial nerve palsies resulting from a ganglion cyst forming on a branch of the sciatic nerve have not been reported. In this paper, we present the case of a 74-year-old man visiting an outpatient clinic complaining of left-sided foot drop and sensory loss in the lower extremity, a lack of strength in his left leg, and a decrease in sensation in the leg for the past month without any history of trauma. Ankle dorsiflexion and great toe extension strength on the left side were Grade I. Ankle plantar flexion and great toe flexion were Grade II. We suspected peroneal and tibial nerve palsy and performed a screening ultrasound, which is inexpensive and rapid. In the operative field, several cysts were discovered, originating at the site where the sciatic nerve splits into peroneal and tibial nerves. After successful surgical decompression and a series of rehabilitation procedures, the patient's neurological symptoms improved. There was no recurrence.

High-Grade Malignant Peripheral Nerve Sheath Tumor Arising From Common Peroneal Nerve Neurofibroma.

This article presents a case report of a 45-year-old male with neurofibromatosis type I (NF1) who developed a high-grade malignant peripheral nerve sheath tumor (MPNST) originating from a neurofibroma within the common peroneal nerve over popliteal fossa. MPNSTs are aggressive tumors associated with NF1, causing significant mortality. The patient underwent tumor resection surgery and received postoperative radiation therapy. Follow-up examinations showed no impairment of motor function and no tumor recurrence after regular MRI evaluation for four years. This article explores the challenges of distinguishing benign neurofibromas from malignant MPNST via MRI image and biopsy, and achieving a balance between tumor excision and preserving nerve functionality during surgical treatment. However, caution is warranted due to the risk of recurrence.

[Superficial peroneal nerve entrapment: ultrasound-guided hydrodissection. A case report]. / Atrapamiento de nervio peroneo superficial: hidrodisección ecoguiada. A propósito de un caso.

Peripheral nerve entrapment is an underdiagnosed pathology when it is not the most common syndromes such as carpal tunnel syndrome or cubital tunnel syndrome. The symptomatic lesion of the superficial peroneal nerve (SPN) has a low incidence, being its diagnosis sometimes complex. It is based on a exhaustive physical examination and imaging tests such as ultrasound (US) or magnetic resonance imaging (RMI). Conservative treatment may sometimes not be sufficient, requiring surgical techniques in refractory cases. We present a patient diagnosed with superficial peroneal nerve entrapment by ultrasound and diagnostic nerve block that was subsequently resolved by hydrodissection technique at the level of the deep crural fascia tunnel. The results were satisfactory with a complete resolution of the clinical process since the application of this technique.

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.

A Curious Case of Common Peroneal Nerve Schwannoma.

Schwannoma or neurilemmoma is a slow-growing tumor that develops from nerve sheaths. It is mostly benign and only rarely transforms into malignancy. The incidence of schwannoma is very low in the lower limbs. Schwannomas developing from the common peroneal nerve is unlikely. A middle-aged male presented with complaints of left knee pain, which was radiating to the left foot, and a painful swelling at the back of the knee. An intralesional excision was done, and the patient made a full recovery with no postoperative complications. The excised specimen was found to be a schwannoma of the common peroneal nerve of the left leg. At the one-month, three-month, and one-year postoperative follow-ups, the patient had no complaints of pain on passive and active dorsiflexion of the foot. There was complete recovery from paresthesia and intact sensation was present. This report shows that asymptomatic schwannomas can sometimes present with symptoms of pain. In such cases, careful and complete excision of the schwannoma can lead to full recovery.