Peroneal intraneural ganglia: the importance of the articular branch. A unifying theory

Ganglion Cysts Arising From the Proximal Tibiofibular Joint: Treatment Approach and Associated Outcomes-A Systematic Review

Background: Proximal tibiofibular joint (PTFJ) ganglion cyst is a rare condition with a high rate of recurrence. Optimal treatment has not yet been determined. Purpose: We aimed to answer the following questions: (1) What are the most common treatments for PTFJ cysts and their associated recurrence rates? (2) What are the risk factors for failure to completely recover from symptoms? (3) What are the risk factors for cyst recurrence? Methods: A systematic review was performed using PubMed and EMBASE databases. Studies were assessed for inclusion and exclusion criteria, and quality analysis following the PRISMA guidelines. Information on demographic, clinical, and treatment characteristics was retrieved from articles. Results: The most common surgical treatment was cyst excision (75.3%). Patients with PTFJ arthrodesis and PTFJ resection had the lowest recurrence rates at 0% and 4.4%, respectively. Complete recovery from symptoms was more common in PTFJ resection (70.8%) than in PTFJ arthrodesis (42.9%). Risk factors for failure to achieve complete recovery from symptoms included intraneural compromise (odds ratio [OR] = 3.93), cyst recurrence (OR = 6.04), and being a contact sports athlete (OR = 9.85). Ligation of the articular branch of the peroneal nerve (PN) was a protective factor (OR = 0.29). A history of knee arthritis was the most important risk factor for cyst recurrence (OR = 20.01); PTFJ arthrodesis was a protective factor (OR = 0.04). Conclusion: This systematic review of level-IV studies found PTFJ resection or arthrodesis to be the most effective treatment options. Intraneural compromise of the common peroneal nerve, cyst recurrence, and participation in contact sports are risk factors for incomplete symptom recovery, and ligation of the articular branch of the PN is a protective factor. Knee arthritis is a risk factor for cyst recurrence. More rigorous study is needed.

Huge Intraneural Ganglion Cyst of Tibial Nerve in a 78-Year-Old Male Patient With Gonarthrosis: A Case Report and Review of the Literature

Intraneural ganglion cysts (IGCs) are mucinous cysts located within peripheral nerves, often associated with an articular nerve branch and the adjacent synovial joint capsule. These cysts, while rare, can occur in various nerves, with the tibial nerve being an infrequent site. Tibial nerve IGCs are rare pathologies. We present a case of a tibial nerve IGC in a 78-year-old male patient with pre-existing grade III gonarthrosis. Furthermore, we performed a brief review of the existing literature for tibial nerve IGCs. To our knowledge, we present the second case of an IGC in a patient with known pre-existing gonarthrosis. This case raises the potential association between IGCs and degenerative knee pathologies and underscores the crucial role of early and accurate diagnosis. Differential diagnosis of nerve sheath tumors and extra-articular calf neuropathy is essential not only for definitive treatment but also to rule out more serious alternative diagnoses. While ultrasound-guided aspiration of cystic fluid with steroid injection and conservative management are also treatment methods defined in the literature, we believe that exploratory surgery is the critical point of treatment. Early and accurate diagnosis is paramount, as delayed diagnosis and treatment may cause persistent functional and sensory deficits.

Ganglion Cysts in the Hallux: A Report of Two Cases

We experienced two cases of intractable hallux ganglion. Case 1 was a 70-year-old woman with a recurrent ganglion and severe pain on the plantar aspect of the hallux. The continuity between the mass and the distal flexor hallucis longus (FHL) tendon sheath was confirmed. The ganglion was resected along with part of the tendon sheath, and the tendon sheath was incised as proximally as possible. Case 2 was a 69-year-old woman with a ganglion on the dorsal aspect of the interphalangeal joint that repeatedly ruptured due to thinning of the skin. The ganglion was contiguous with the joint capsule but not with the FHL tendon sheath, and the entire capsule was resected. There was no recurrence one year after surgery in either case. The risk of recurrence of an intractable hallux ganglion can be reduced by blocking the synovial supply route and lowering the pressure inside the joint or tendon sheath.

The current trend of proximal tibiofibular ganglion cyst: A summary of 7 case series and 61 case reports

Purpose

To review the different types of ganglion cysts surrounding the proximal tibio-fibular joint, their management options, outcomes, and recurrence.

Design

Descriptive analytical review.

Results

7 case series consisting of a total of 159 patients and 61 case reports consisting of 80 patients (with three patients having bilateral pathology) were included in this review. (Total cysts 159 + 83 = 242). The mean age was 41 years, and 71 % of the patients were males. 96.5 % of the cases were managed operatively, out of which 98 % of patients felt improvement in local symptoms and 71.5 % had improvement in neurological symptoms. Complete excision of the cyst is the primary mode of operative management. Many added procedures with complete excision are to mitigate the risk of recurrence. The recurrence rate of aspiration, simple excision alone, simple excision with recurrent articular branch neurectomy, and simple excision with PTFJ procedures were 77 %, 56 %, 11.5 %, and 0 %, respectively. Outcomes beyond recurrence were poorly reported.

Conclusion

There is not enough literature regarding the topic from which any formal systematic review can be done. Our summary suggests that aspiration alone or with steroid injection is associated with the highest recurrence rates among all the procedures. Complete excision with recurrent articular branch neurectomy should be the primary management. Revision cyst excision in isolation is an inadequate treatment option, therefore should be done in conjunction with PTFJ arthrodesis, which reduces the recurrence rates. Better quality studies are needed that report patient-centered outcomes and morbidities following PTFJ procedures.

Tarsal tunnel ganglion cyst: intraneural or extraneural site?

Intraneural ganglion cysts are very uncommon lesions, whose diagnosis has increased since the articular theory and the description of the MRI findings were established. We present a case report of a 59-year-old man with symptoms of tarsal tunnel syndrome. Foot and ankle MRI demonstrated the presence of an intraneural cystic lesion in the posterior tibial neve and its connection with the subtalar joint through an articular branch. The identification of the specific radiological signs like the «signet ring sign» allowed establishing an adequate preoperative diagnosis, differentiating it from an extraneural lesion and facilitating the articular disconnection of the nerve branch during surgery.

Femoral intraneural ganglion cyst: the first confirmed case report

BACKGROUND

Ganglion cysts affecting nerve are rare causes of neuropathy. The formation of intraneural ganglion cysts, once controversial, has recently been clarified. We describe the first modern description of a femoral intraneural ganglion cyst at the hip region.

METHODS

A patient presented with a 1 year history of radiating pain, quadriceps weakness and anteromedial leg numbness was found to have a femoral intraneural cyst with a hip joint connection on MRI.

RESULTS

Surgical disconnection of the articular branch led to improvement of the neuropathy and resolution of the cyst on postoperative MRI.

CONCLUSIONS

The unifying articular (synovial) theory describes the joint origin of intraneural cysts, even when they occur in unusual locations, and their propagation into the parent nerve. Knowledge of this theory can improve outcomes; surgery needs to address the joint origin or capsulolabral defect lest recurrence ensue.

Tibial intraneural ganglion cysts at the superior tibiofibular joint treated with joint resection alone: a proof of concept

BACKGROUND

Intraneural ganglion cysts involving the tibial nerve are rare. Recent evidence has supported an articular (synovial) theory to explain the joint-related origin of these cysts; however, optimal operative treatment for cysts originating from the STFJ remains poorly understood. Therefore, we present a novel strategy: addressing the joint itself without addressing the articular branch and/or the cyst.

METHODS

Records of patients with tibial intraneural ganglion cysts with a connection to the STFJ who were treated with a joint resection alone at a single academic institution were reviewed. The clinicoradiographic features, operative intervention, and postoperative course were recorded.

RESULTS

We identified a consecutive series of 7 patients. These patients (4/7 male, 57%) were 43 (range 34-61) years of age and all presented with symptoms of neuropathy. The patients underwent resection of the synovial surfaces of the STFJ without disconnection of the articular branch or decompression of the cyst. Postoperatively, three patients regained partial motor function (43%, n=7), although four patients noted continued sensory abnormality (57%, 4/7). All six patients with postoperative MRIs had some evidence of regression of the cyst.

CONCLUSIONS

This novel surgical technique serves as a proof of concept-highlighting the fact that treating the primary source (the joint origin) can be effective in eliminating the secondary problem (the cyst itself). While this study shows that this simplified approach can be employed in select cases, we believe that superior results (faster, fuller recovery) can be achieved with combinations of disconnecting the articular branch, decompressing the cyst, and/or resecting the joint.

Acute Foot Drop Caused by Intraneural Ganglion Cyst of the Peroneal Nerve: Literature Review and Case Report

BACKGROUND

Foot drop (FD) is characterized by an inability to lift the foot against gravity because of dorsiflexor muscle weakness. The aim of the present study is to report a clinical case of acute non-traumatic FD in patients with peroneal intraneural ganglion, after performing a scoping review on the methodological management of this disease.

METHODS

We performed a review of the literature and reported the case of a 49-year-old man with acute FD caused by an intraneural ganglion cyst of the peroneal nerve.

RESULTS

Out of a total of 201 articles, 3 were suitable for our review beyond our case report. The acute FD caused by peroneal intraneural ganglion can be managed by a careful clinical-instrumental differential diagnosis. A targeted surgery with subsequent rehabilitation produced a satisfactory motor recovery.

CONCLUSIONS

Acute FD requires an appropriate diagnostic-therapeutic framework to identify and effectively treat the causes in order to promote complete recovery.

Recurrent Peroneal Intraneural Ganglion Cyst: Management and Review of the Literature

Intraneural ganglion cysts have been reported to affect the common peroneal nerve. Peroneal intraneural ganglion cysts are managed through surgical intervention. Despite surgical intervention, intraneural ganglion cysts can recur. Common intraneural ganglion cyst recurrence patterns have been proposed based on the initial surgical management of the cyst. These patterns all emphasize the importance of treatment of the proximal tibiofibular (TF) joint to reduce the risk of cyst recurrence. Although joint resection is the favored intervention in the literature, joint arthrodesis is an option for certain patients. Here, we present a case of a peroneal intraneural ganglion cyst and its recurrence in a 36-year-old male who had previously undergone surgical removal of the cyst three months prior, as well as a review of the current literature that aims to add to our current understanding of intraneural cysts.

Cubital Tunnel Syndrome Due to Multiple Intraneural Cysts at Elbow: A Case Report and Review of Literature

Cubital tunnel syndrome is a common disorder that affects the upper limb and involves compression of the ulnar nerve. However, this syndrome is rarely caused by multiple intraneural ganglion cysts. Of all intraneural ganglion cysts, only 9% affect the elbow. This study presents a case report of a 73-year-old female patient who manifested pain, numbness, tingling, and paralysis of the medial aspect of her left forearm, fourth, and fifth fingers of the left hand for six months. Intraoperative findings showed multiple intraneural cysts at the left elbow, which were confirmed via histopathology. The cysts were surgically excised, whereas the ulnar nerve was released into the cubital tunnel and anteriorly transposed. Complete sensory and motor recovery were achieved. Although similar cases of intraneural cysts were reported in the literature, this case has the uniqueness of the unusual number and site of intraneural cysts in the ulnar nerve on the background of osteoarthritic changes. Therefore, the aim of reporting this case is to increase awareness of the presence of these cysts when the symptoms are severe.

The value of high-resolution imaging in an occult peroneal intraneural ganglion cyst: illustrative case

BACKGROUND

Foot drop is a common complaint with a broad differential diagnosis making imaging a key part of the diagnostic workup. The authors present a patient with an occult peroneal intraneural ganglion cyst who underwent imaging with high-frequency ultrasound (US) and high-resolution magnetic resonance imaging (MRI) to highlight the role of such techniques in cases of peroneal neuropathy.

OBSERVATIONS

Intraneural ganglion cysts are emerging as a common cause of common peroneal neuropathy. Imaging with US and MRI is a valuable tool used to illustrate the pertinent anatomy and identify the articular branch joint connection and cyst as part of the surgical planning and definitive management.

LESSONS

Intraneural ganglion cysts can be small or nearly invisible and failure to appreciate the intraneural cyst can lead to symptom or cyst persistence or recurrence. High-resolution modalities can be useful in the diagnosis and surgical planning of difficult cases.

Does complete regression of intraneural ganglion cysts occur without surgery?

PURPOSE

The dynamic nature of intraneural ganglion cysts, including spontaneous expansion and regression, has been described. However, whether these cysts can regress completely in the absence of surgical management has important therapeutic implications. Therefore, we aim to review the literature for cyst regression without surgical intervention.

METHODS

We reviewed our database of 970 intraneural ganglion cysts in the literature to search for evidence of complete regression based on strict radiologic confirmation, either spontaneously, or after percutaneous cyst aspiration or steroid injection.

RESULTS

We did not find any examples of complete regression without surgical treatment that met inclusion criteria. Spontaneous regression was reported in four cases; however, only two cases had follow-up imaging, both of which demonstrated residual cysts. Nineteen cases of percutaneous intervention were found in the literature, 13 of which reported clinical improvement following aspiration/steroid injection; however, only seven cases had available imaging. Only two cases reported complete resolution of cyst on MR imaging at follow-up, but reinterpretation found residual intraneural cyst in both cases.

CONCLUSION

We believe that pathology (structural abnormalities and/or increased joint fluid) always exists at the joint origin of intraneural ganglion cysts which persist even with regression of the cyst. The persistence of a capsular abnormality or defect can lead to recurrence of the cyst in the future, and while imaging may show dramatic decreases in cyst size, truly focused assessment of images will show a tiny focus of persistent intraneural cyst at the joint origin. Thus, expectant management or percutaneous intervention may lead to regression, but not complete resolution, of intraneural ganglion cysts.

Intraneural or extraneural ganglion cysts as a cause of cubital tunnel syndrome: A retrospective observational study

Purpose

Cubital tunnel syndrome caused by ganglion cysts has rarely been reported. The purpose of this study was to evaluate the surgical treatment outcomes of a patient diagnosed with cubital tunnel syndrome caused by intraneural or extraneural cysts and to summarize our experience.

Method

In total, 34 patients were evaluated retrospectively from January 2011 to January 2020 with a follow-up of more than 24 months. Preoperative data, such as demographic data, clinical symptoms, physical examination findings, and laboratory tests, were all recorded and pre-operative and post-operative data were compared. The function was evaluated by the modified Bishop scoring system and the McGowan grade at the last follow-up.

Results

Improvement of interosseous muscle strength, the Visual Analog Scale (VAS), 2-point discrimination (2-PD), electromyogram (EMG) result, Wartenberg sign, claw hand, and weakness could be clearly observed in all patients. Extraneural cysts were completely removed and the pedicles of the cysts were ligated. Intraneural cysts were incised and drained, and part of their cyst walls were removed using a microsurgical technique. All patients underwent anterior subcutaneous transposition (AST). At the last follow-up, McGowan's (0-IIa) grade increased from seven patients (20.6%) preoperatively to 27 patients (79.4%); the excellent and good rate according to the modified Bishop scoring system was 82.4% (28 patients), and all patients had no symptoms of recurrence after surgery.

Conclusion

The treatment of cubital tunnel syndrome caused by intraneural or extraneural cysts achieved good long-term results through extraneural cyst resection or intraneural cyst incision and drainage combined with subcutaneous transposition. Early diagnosis and surgical treatment are essential for the patient's postoperative recovery.

Management and outcomes of proximal tibiofibular joint ganglion cysts: A systematic review

BACKGROUND

Proximal tibiofibular joint (PTFJ) ganglion cysts are rare; however, their optimal management remains unclear. This study aimed to systematically review the surgical treatment options with a focus on recurrence rates and complications.

METHODS

A systematic review of the literature was performed, searching three electronic databases, according to the PRISMA guidelines. The presentation, treatment, and outcomes of PTFJ ganglion cysts of minimum 1-year follow-up was collected. Study quality was assessed using the Modified Downs and Blacks checklist. Surgical interventions were considered ordinally from simple to more extensive as follows; cyst aspiration, cyst excision, cyst excision with an intervention to the PTFJ, either a hemi-resection or arthrodesis.

RESULTS

Twenty-two studies comprising 100 patients (101 knees) met inclusion criteria. Among all patients, pain was present in 59.7%, a lateral fullness in 71.6% and symptoms of the common peroneal nerve in 57.4%. The overall rate of recurrence after primary treatment was 28.9%. Recurrence rates for aspiration, cyst excision, PTFJ hemi-resection and PTFJ arthrodesis were 81.8%, 27.4%, 8.3% and 0%, respectively. Revision excision for recurrence failed in all cases. Outcomes beyond recurrence were poorly reported.

CONCLUSION

Addressing the PTFJ at the time of cyst excision reduces recurrence rates, however, the morbidity from PTFJ hemi-resection and arthrodesis are poorly reported. Whilst primary excision offers resolution in most cases (73%), revision cyst excision in isolation for the treatment of recurrent cysts is an inadequate treatment option. Cyst aspiration is ineffective. Data pertaining to patient reported outcomes for all treatment types are lacking.

Differential diagnosis and treatment of foot drop caused by an extraneural ganglion cyst above the knee: A case report

BACKGROUND

One of the causes of foot drop is compression of the common peroneal nerve caused by space-occupying lesions such as a synovial cyst or a ganglion cyst. Most previous reports have involved compressive common peroneal neuropathy by intraneural ganglion cysts and synovial cysts. Compression of the peroneal nerve by extraneural ganglion cysts is rare. We report a rare case of compressive common peroneal neuropathy by an extraneural ganglion cyst.

CASE SUMMARY

A 46-year-old man was hospitalized after he reported a right foot drop for 1 mo. Manual muscle testing revealed scores of 1/5 on dorsiflexion of the right ankle. Hypoesthesia and paresthesia on the right lateral leg and foot dorsum were noted. He was diagnosed with a popliteal cyst by using electrophysiologic study and popliteal ultrasound (US). To facilitate common peroneal nerve (CPN) decompression, 2 cc of sticky gelatinous material was aspirated from the cyst under US guidance. Electrical stimulation and passive and assisted active ROM exercises of the right ankle and strengthening exercises for weak muscles using elastic band were prescribed based on the change of muscle power. A posterior leaf spring ankle-foot orthosis was prescribed to assist the weak dorsiflexion of the ankle. Follow-up US revealed that the cystic lesion was growing and magnetic resonance imaging demonstrated compression of the CPN by the cystic mass. The cyst was resected to prevent impending compression of the CPN.

CONCLUSION

Precise diagnosis and immediate treatment are important in cases of compressive common peroneal neuropathy caused by an extraneural cyst.

Juxtaneural ganglia arising from the hip joint: focus on magnetic resonance imaging findings and clinical manifestations

OBJECTIVE

To present cases of juxtaneural ganglia arising from the hip with a discussion of the magnetic resonance imaging (MRI) findings, presenting symptoms, and possible treatment option.

MATERIALS AND METHODS

Two radiologists performed a consensus review of MRI scans obtained between January 2013 and March 2021 to identify patients with juxtaneural ganglia around the hip. A total of 11 patients with 11 juxtaneural ganglia were identified. Medical records and MRI findings were retrospectively reviewed.

RESULTS

Eight patients had lesions involving the sciatic nerve, and three patients had lesions involving the obturator nerve. Sciatic ganglia arose from a paralabral cyst in the posteroinferior quadrant and continued through a narrow channel running along the posterior acetabulum, showing increased diameter in the sciatic foramen and intrapelvic portion. Obturator ganglia showed a J- or reverse J-shape on the coronal imaging plane and extended from a paralabral cyst in the anteroinferior quadrant via the obturator canal. Nine patients (9/11, 81.8%) had symptoms resembling those of lumbosacral radiculopathy. Four patients underwent arthroscopic surgery, and one patient underwent ultrasound-guided aspiration, all of whom showed partial improvement. Spontaneous decrease in the extent of the ganglion was observed in three patients (3/11, 27.3%).

CONCLUSION

This article describes rare cases of juxtaneural ganglia arising from the hip joint and involving the sciatic and obturator nerves. The lesions share similar MRI findings, and each type of cyst (sciatic or obturator ganglia) involves a specific labral quadrant.

Acute-Onset Footdrop Caused by Intraneural Ganglion Cyst of the Common Peroneal Nerve: The Effects of Extraneural Pressure Gradients on Cyst Propagation

Ganglion cysts are relatively common entities, but intraneural ganglia within peripheral nerves are rare and poorly understood. We present a case of a 51-year-old man who presented with acute left dropfoot. Initial magnetic resonance imaging (MRI) was misinterpreted as common peroneal neuritis consistent with a traction injury corroborated by the patient's history. However, after surgical decompression and external neurolysis were performed, the patient's symptoms worsened. Repeated MRI revealed an intraneural ganglion cyst of the common peroneal nerve with connection to the superior tibiofibular joint by means of its anterior recurrent branch that was evident retrospectively on preoperative MRI. It is crucial to carefully inspect atypical cases to further recognize and appreciate the dynamic aspect of this disease or "roller-coaster" phenomenon. Intraneural ganglion cysts rely heavily on intraneural and extraneural pressure gradients for propagation, which can be drawn from the expanded work of the unifying articular theory. This report emphasizes the importance of understanding the pathoanatomical and hydraulic factors to appropriately identify and treat intraneural ganglion cysts. Increased recognition of this pathologic entity as a differential diagnosis for acute onset dropfoot is also highlighted.

Intraneural ganglion cysts originating from the hip joint: A single-center experience

INTRODUCTION/AIMS

Intraneural ganglion cysts (INGCs) are non-neoplastic mucinous cysts within the epineurium of peripheral nerves. Characteristics of INGCs around the hip joint have not been adequately described. We aimed to describe clinical features, imaging findings, and treatment outcomes in patients with INGCs originating from the hip joint.

METHODS

We retrospectively included cystic lesions around the hip joint satisfying the following inclusion criteria over 6 years: (1) multilocular elongated hyperintense cystic mass on T2-weighted imaging; and (2) distribution along the course of the peripheral nerve and its branches on magnetic resonance imaging (MRI).

RESULTS

Six patients with an INGC around the hip joint were identified. Parent peripheral nerves were the sciatic nerve (four patients), the superior gluteal nerve (one patient), and the nerve to quadratus femoris (one patient). Buttock, groin, or lower extremity pain/paresthesias were the initial symptoms in all patients. INGCs within the articular branches of the hip joint were identified on MRI. Four patients underwent arthroscopic debridement and capsulotomy. All patients showed generally favorable outcome regardless of treatment.

DISCUSSION

Physicians should consider the possibility of INGCs originating from the hip joint as a cause of nontraumatic hip, buttock, or lower extremity pain. This can occur in any nerve innervating the hip joint, and usually it originates in the posterior capsule of the hip joint. Arthroscopic surgery shows promising results; however, more information about the surgical technique and long-term follow-up results are needed.

Intraneural ganglion cyst of the common peroneal nerve causing foot drop in a 12-year old child

OBJECTIVES

Intraneural ganglia are benign fluid-filled cysts contained within the subepineurial space of peripheral nerves. The common peroneal nerve at the fibular neck is by far the most frequently involved, although other nerves can be affected as well. Although the differential diagnosis of foot drop in adults and children show some differences, clinical presentation, diagnostic workup, treatment and follow-up of intraneural ganglia are quite similar in both groups. The primary objective was to create an overview of intraneural ganglia in children, with an emphasis on diagnostic workup and potential pitfalls during neurosurgical intervention, based on all available literature concerning this topic and own center experiences. As a secondary objective, we tried to raise the awareness concerning this unique cause of foot drop in childhood.

PATIENTS AND METHODS

We performed a review of the literature, in which children who developed foot drop secondary to an intraneural ganglion cyst of the common peroneal nerve were examined. A total of eleven articles obtained from MEDLINE were included. Search terms included: "pediatric", "children", "child", "intraneural ganglia", "intraneural ganglion cysts", "foot drop", "peroneal nerve" and "fibular nerve". Additional studies were identified by checking reference lists. Furthermore, we present the case of a 12-year old girl with foot drop caused by an intraneural ganglion cyst. She underwent cyst decompression with evacuation of intraneural cyst fluid and articular branch disconnection. PRISMA and CARE statement guidelines were followed.

RESULTS

We hypothesize that minor injury caused a breach in the joint capsule, resulting in synovial fluid egression along the articular nerve branch, corroborating the unifying articular theory and emphasizing the need for ligation of said branch. Foot drop is a predominant characteristic, explained by the proximity of the anterior tibial muscle motor branch near the articular branch nerve. In children, satisfactory motor recovery after surgical decompression is to be expected.

CONCLUSION

Sudden or progressive foot drop in children warrants an exhaustive neurophysiological and radiological workup. The management of intraneural ganglia is specific, consisting of nerve decompression, articular branch ligation and joint disarticulation, if deemed necessary. Our surgical results support the unifying articular theory and emphasize the importance of ligation and transection of the articular branch nerve, distally from the anterior tibial muscle branch, in order to prevent intraneural ganglia recurrence. This well-documented case adds depth to the current literature on this sparsely reported entity.

A novel mechanism for the formation and propagation of neural tumors and lesions through neural highways

By recognizing anatomic and radiologic patterns of rare and often misdiagnosed peripheral nerve tumors/lesions, we have defined mechanisms for the propagation of neural diseases. The novel concept of the nervous system serving as a complex system of "highways" driving the neural and perineural spread of these lesions is described in three examples: Intraneural dissection of joint fluid in intraneural ganglion cysts, perineural spread of cancer cells, and dissemination of unknown concentrations of neurotrophic/inhibitory factors for growth in hamartomas/choristomas of nerve. Further mapping of these pathways to identify the natural history of diseases, the spectrum of disease evolution, the role of genetic mutations, and how these neural pathways interface with the lymphatic, vascular, and cerebrospinal systems may lead to advances in targeted treatments.

Intraneural ganglion cyst of the lumbosacral plexus mimicking L5 radiculopathy: A case report

BACKGROUND

Intraneural ganglion cysts are benign gelatinous masses that form within the epineurium of a peripheral nerve. Only few cases of intraneural ganglion cyst arising from the hip joint have been reported.

CASE SUMMARY

A previously healthy 65-year-old woman who had been experiencing left buttock pain radiating to the dorsum of the foot for 2 years visited our clinic. Prior to visiting the clinic, she underwent lumbar spine magnetic resonance imaging and received physiotherapy, pain killers, and epidural injections based on a presumptive diagnosis of spinal stenosis for 2 years in other hospitals. Repeat magnetic resonance imaging revealed joint connection of the articular branch of the hip joint and rostral extension of the cyst along the L5 spinal nerve near the L5-S1 neural foramen. The patient was diagnosed with intraneural ganglion cyst arising from the articular branch of the hip joint based on high-resolution magnetic resonance neurography. Using the arthroscopic approach, a cystic opening within the intra-articular space was detected, and cyst decompression was then performed. The pain in the left leg was significantly relieved during the 6-mo follow-up.

CONCLUSION

Although intraneural ganglion cysts arising from the hip joint are rare, they can cause typical radicular pain and mimic common L5 radiculopathy. Typical cyst ascent phenomenon starting from the termination of the articular branch on magnetic resonance imaging is a crucial finding indicative of intraneural ganglion cysts arising from the hip joint.

The Addition of a Nerve Transfer to the Treatment of Peroneal Neuropathy Secondary to Intraneural Ganglion: Case Series

ABSTRACT

Peroneal intraneural ganglia are rare, and their management is controversial. Presently, the accepted treatment of intraneural ganglia is decompression and ligation of the articular nerve branch. Although this treatment prevents recurrence of the ganglia, the resultant motor deficit of foot drop in the case of intraneural peroneal ganglia is unsatisfying. Foot drop is classically treated with splinting or tendon transfers to the foot. We have recently published a case report of a peroneal intraneural ganglion treated by transferring a motor nerve branch of flexor hallucis longus into a nerve branch of tibialis anterior muscle in addition to articular nerve branch ligation and decompression of the intraneural ganglion to restore the patient's ability to dorsiflex. We have since performed this procedure on 4 additional patients with appropriate follow-up. Depending on the initial onset of foot drop and time to surgery, nerve transfer from flexor hallucis longus to anterior tibialis nerve branch may be considered as an adjunct to decompression and articular nerve branch ligation for the treatment of symptomatic peroneal intraneural ganglion.

High-resolution MRI of a peroneal intraneural ganglion cyst arising from the knee joint: illustrative case

BACKGROUND

The advancement of high-resolution imaging and increased clinical experience have led to an increased understanding of the formation and treatment of intraneural ganglion cysts. Nearly all intraneural ganglion cysts in the common peroneal nerve have been reported to arise from a joint connection to the superior tibiofibular joint. The authors have identified four cases of intraneural ganglion cysts arising from the knee joint itself; however, none of these reported cases were well described, documented, or illustrated with high-resolution imaging.

OBSERVATIONS

Here the authors present the case of an intraneural ganglion cyst arising from the knee joint and causing intermittent weakness and pain. The articular branch to the knee joint was clearly demonstrated on high-resolution magnetic resonance imaging and confirmed at surgical exploration. The patient was treated with articular branch ligation and has had complete resolution of his symptoms without recurrence of the cyst on follow-up imaging.

LESSONS

This case adds to the mounting evidence that intraneural cyst pathology is dependent on a connection to a synovial joint as stated in the unifying theory of intraneural cyst development.

The articular branch of the peroneal nerve to the proximal tibiofibular joint descends at a mean height of approximately 18 mm distal to the postero-lateral tip of the fibular head

PURPOSE

The aim of the study was to evaluate the anatomical details of the articular branch of the peroneal nerve to the proximal tibiofibular joint and to project the height of its descent in relation to the fibular length.

METHODS

Twenty-five lower extremities were included in the study. Following identification of the common peroneal nerve, its course was traced to its division into the deep and superficial peroneal nerve. The articular branch was identified. The postero-lateral tip of the fibular head was marked and the interval from this landmark to the diversion of the articular branch was measured. The length of the fibula, as the interval between the postero-lateral tip of the fibular head and the tip of the lateral malleolus, was evaluated. The quotient of descending point of the articular branch in relation to the individual fibular length was calculated.

RESULTS

The articular branch descended either from the common peroneal nerve or the deep peroneal nerve. The descending point was located at a mean height of 18.1 mm distal to the postero-lateral tip of the fibular head. Concerning the relation to the fibular length, this was at a mean of 5.1%, starting from the same reference point.

CONCLUSION

The articular branch of the common peroneal nerve was located at a mean height of 18.1 mm distal to the the postero-lateral tip of the fibular head, respectively, at a mean of 5.1% of the whole fibular length starting from the same reference point. These details represent a convenient orientation during surgical treatment of intraneural ganglia of the common peroneal nerve, which may result directly from knee trauma and indirectly from ankle sprain.

Ganglion Cysts of the Proximal Tibiofibular Joint: Low Risk of Recurrence After Total Cyst Excision

BACKGROUND

Peroneal nerve neuropathy due to compression from tumors or tumor-like lesions such as ganglion cysts is rare. Few case series have been published and reported local recurrence rates are high, while secondary procedures are frequently employed.

QUESTIONS/PURPOSES

(1) What are the demographics of patients with ganglion cysts of the proximal tibiofibular joint, and what proportion of them present with intraneural cysts and peroneal nerve palsy? (2) What Musculoskeletal Tumor Society (MSTS) scores do patients with this condition achieve after decompression surgery with removal of the ganglion cyst, but no arthrodesis of the tibiofibular joint? (3) What proportion of patients experience local recurrence after surgery?

METHODS

Between 2009 to 2018, 30 patients (29 primary cases) were treated for chronic peroneal palsy or neuropathy due to ganglion cysts of the proximal tibiofibular joint at two tertiary orthopaedic medical centers with total resection of the cystic lesion. MRI with contrast and electromyography (EMG) were performed preoperatively in all patients. The minimum follow-up for this series was 1 year (median 48 months, range 13 to 120); 14% (4 of 29) were lost to follow-up before that time. The MSTS score was recorded preoperatively, at 6 weeks postoperatively, and at most-recent follow-up.

RESULTS

A total of 90% of the patients were male (26 of 29 patients) and the median age was 67 years (range 20 to 76). In all, 17% (5 of 29) were treated due to intraneural ganglia. Twenty-eight percent (8 of 29) presented with complete peroneal palsy (foot drop). The mean MSTS score improved from 67 ± 12% before surgery to 89 ± 12% at 6 weeks postoperative (p < 0.001) and to 92 ± 9% at final follow up (p = 0.003, comparison with 6 weeks postop). All patients improved their scores. A total of 8% (2 of 25 patients) experienced local recurrence after surgery.

CONCLUSION

Ganglion cysts of the proximal tibiofibular joint occurred more often as extraneural lesions in older male patients in this small series. Total excision was associated with improved functional outcome and low risk of neurologic damage and local recurrence, and we did not use any more complex reconstructive procedures. Tendon transfers may be performed simultaneously in older patients to stabilize the ankle joint, while younger patients may recover after decompression alone, although larger randomized studies are needed to confirm our preliminary observations.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Intraneural Peroneal Ganglion Cyst Excision in a Pediatric Patient: A Case Report

CASE

A 14-year-old female presented with a profound foot drop after trauma to the right leg. Clinical examination and electrodiagnostic studies demonstrated a dense palsy of the common peroneal nerve. Magnetic resonance imaging revealed an intraneural peroneal ganglion cyst at the fibular neck. Surgical treatment included decompression and transection of the articular branch to the proximal tibiofibular joint. At the 1-year follow-up, the patient demonstrated complete recovery of peroneal nerve function.

CONCLUSIONS

This case demonstrates a rare finding of a pediatric intraneural peroneal ganglion cyst. The presentation and treatment is well-documented and adds depth to the literature on a sparsely reported condition.

[A case of tibial nerve palsy due to intraneural ganglion cysts]

A 39-year-old man presented with an 8-month history of pain and paresthesia of the right foot sole and difficulty in the right toe dorsiflexion. A neurological examination revealed weakness in performing both the ankle and right foot toe dorsiflexion, reduced right planta pedis sensation, and absent right Achilles tendon reflex. Tinel's sign was present on the right popliteal fossa and medial part of the right ankle. MRI of the right knee showed multiple cystic lesions in his right tibial nerve. The cystic lesions extended from the popliteal fossa and were thought to be intraneural ganglion cysts. On MRI performed 4 months later, most of the cystic lesions spontaneously vanished. Therefore, intraneural ganglia should be considered when atypical mononeuropathy, such as tibial nerve palsy, is present.

Clinical outcome after decompression of intraneural peroneal ganglion cyst and its morphologic correlation to postoperative nerve ultrasound

OBJECTIVE

Intraneural ganglion cysts are rare and benign mucinous lesions that affect peripheral nerves, most frequently the common peroneal nerve (CPN). The precise pathophysiological mechanisms of intraneural ganglion cyst development remain unclear. A well-established theory suggests the spread of mucinous fluid along the articular branch of the peroneal nerve as the underlying mechanism. Clinical outcome following decompression of intraneural ganglion cysts has been demonstrated to be excellent. The aim of this study was to evaluate the correlation between clinical outcome and ultrasound-detected morphological nerve features following decompression of intraneural ganglion cysts of the CPN.

METHODS

Data were retrospectively analyzed from 20 patients who underwent common peroneal nerve ganglion cyst decompression surgery at the Universität Ulm/Günzburg Neurosurgery Department between October 2003 and October 2017. Postoperative clinical outcome was evaluated by assessment of the muscular strength of the anterior tibial muscle, the extensor hallucis longus muscle, and the peroneus muscle according to the Medical Research Council grading system. Hypesthesia was measured by sensation testing. In all patients, postoperative morphological assessment of the peroneal nerve was conducted between October 2016 and October 2017 using the iU22 Philips Medical ultrasound system at the last routine follow-up appointment. Finally, the correlations between morphological changes in nerve ultrasound and postoperative clinical outcomes were evaluated.

RESULTS

During the postoperative ultrasound scan an intraneural hypoechogenic ring structure located at the medial side of the peroneal nerve was detected in 15 (75%) of 20 patients, 14 of whom demonstrated an improvement in motor function. A regular intraneural fasicular structure was identified in 3 patients (15%), who also reported recovery. In 1 patient, a recurrent cyst was detected, and 1 patient showed intraneural fibrosis for which recovery did not occur in the year following the procedure. Two patients (10%) developed neuropathic pain that could not be explained by nerve ultrasound findings.

CONCLUSIONS

The results of this study demonstrate significant recovery from preoperative weakness after decompression of intraneural ganglion cysts of the CPN. A favorable clinical outcome was highly correlated with an intraneural hypoechogenic ring-shaped structure on the medial side of the CPN identified during a follow-up postoperative ultrasound scan. These study results indicate the potential benefit of ultrasound scanning as a prognostic tool following decompression procedures for intraneural ganglion cysts of the CPN.

Choosing the target wisely: partial tibial nerve transfer to extensor digitorum motor branches with simultaneous posterior tibial tendon transfer. Could this be a way to improve functional outcome and gait biomechanics?

OBJECTIVE

The objective of this study was clinical assessment of the reduction of pathological motor phenomena with the recovery of long toe extensors, and evaluation of functional outcome with simultaneous nerve and tendon transfer in cases of common peroneal nerve (CPN) injuries.

METHODS

Seven male patients (mean age 26.4 years) received a partial tibial nerve transfer to the extensor hallucis longus muscle (MEHL) and extensor digitorum longus muscle (MEDL) motor branches, after a mean of 2.7 months following a traction-type injury to the CPN. Tibialis posterior muscle (MTP) tendon transfer through the interosseous route was performed on the same day. The follow-up period included a clinical neurological examination, a modified Stanmore System questionnaire (MSSQ), electromyographic examination of the interference pattern, and a video-based analysis of the gait biomechanics in the 3rd and 12th months. Video analysis of the gait investigated the presence or reduction of "stair-climbing maneuver" (SCM), foot slap (FS), and foot stability during the gait cycle.

RESULTS

The average range of active dorsiflexion in the 3rd month was 0.85°. SCM accompanied walking in 6 patients (86%). FS accompanied walking in 3 patients (43%) and 3 patients (43%) avoided FS by planting the entire foot on the ground. All patients required orthopedic support (shoe inserts) to compensate for mediolateral foot instability. The average MSSQ score was 80.4 points. The average duration for the effective recovery of function (≥ 4 points on the Medical Research Council grading system) of long toe extensors was 11.2 months. The average range of active dorsiflexion in the 12th month increased to 4.4°. A reduction of FS was observed in 5 patients (71%). Excessive foot eversion was reduced in 4 patients (57%). Another 3 patients (43%) required no specific orthopedic shoe inserts. Reduction of pathological motor phenomena with recovery of the long toe extensors resulted in an increase of functional outcome. The average MSSQ score after 12 months was 92.4 points.

CONCLUSIONS

Partial tibial nerve transfer to the motor branches of the extensor hallucis longus and the long toe extensors along with the simultaneous tibialis posterior tendon transfer produce the reduction of FS and bring mediolateral stability to the foot, i.e., improved gait biomechanics. The reduction of pathological motor phenomena at the time of recovery of the long toe extensors is reflected in an increase in patients' functional perception of the injured lower extremity during daily walking.

Acute Complete Foot Drop Caused by Intraneural Ganglion Cyst without a Prior Traumatic Event

Intraneural ganglion cysts are benign soft-tissue masses located in the epineurium of peripheral nerves. They originate from nearby joint connections via articular branches. Traumatic events seem to play a role in their pathogenesis as well. Clinical manifestations include pain over the area of the cyst, palpable tender mass, hypoesthesia, and muscle weakness depending on the affected nerve. Our case highlights an uncommon clinical manifestation of this entity with acute foot drop, as the primary symptom, without any previous traumatic event, enriching by this way the current diagnostic thinking process of clinical physicians. We report a case of a 42-year-old military officer who presented to our emergency department with acute foot drop that appeared during a march. Initially, the common peroneal palsy was misdiagnosed as L5-S1 disc herniation, but investigation with lumbar MRI scan led to rejection of our primary diagnosis. After performing EMG of the lower extremity and knee MRI, an intraneural ganglion cyst of the common peroneal nerve was diagnosed. Patient was treated with surgical decompression of the cyst, followed by ligation and complete resection of the articular branch, as well as disarticulation of the superior tibiofibular joint. At a twelve-month follow-up, the patient showed significant functional recovery. This is, to the best of our knowledge, the first case of intraneural ganglion cyst manifested with an acute complete foot drop without a clear prior traumatic event. We underline the need for a high index of suspicion when dealing with cases of acute peroneal palsy without any accompanying symptoms.

Joint Outcomes Following Surgery for Superior Tibiofibular Joint-Associated Peroneal Intraneural Ganglion Cysts

BACKGROUND

Intraneural ganglion cysts are joint-connected, with the primary pathology residing in the associated joint. For peroneal intraneural ganglion cysts, the surgical strategy can include resection of the synovial surface of the superior tibiofibular joint (STFJ). However, the rate of instability postoperatively is unclear.

OBJECTIVE

To evaluate the rate of STFJ instability, following surgery for peroneal intraneural ganglion cysts. The second goal of the study was to assess the relationship between volume of resection of the STFJ and risk of extraneural recurrence.

METHODS

We performed a retrospective analysis of a cohort of patients with peroneal intraneural ganglion cysts. We analyzed clinical factors, including recurrence, and assessed the rate of postoperative STFJ instability. We created 3-dimensional models of the STFJ pre- and postoperatively to compare the volume of resection in recurrent cases and nonrecurrent cases using a case-control design.

RESULTS

The total cohort consisted of 65 subjects. No patient had evidence of radiological or clinical instability of the STFJ postoperatively. Extraneural radiological recurrence occurred in 6 (9%) patients. No intraneural recurrences were observed. The average volume of resection for patients with recurrence was 1349 mm3 (SD = 1027 mm3) vs 3018 mm3 (SD = 1433 mm3) in controls that did not have a recurrence (P = .018).

CONCLUSION

This study supports performing an aggressive STFJ resection to minimize the risk of extraneural recurrence. Superior tibiofibular joint resection is not associated with postoperative joint instability. A smaller volume resection is correlated with recurrence risk.

A rare cause of unilateral hypoglossal nerve palsy: case report of intraneural ganglion cyst of the hypoglossal nerve and review of the literature

Benign lesions of the soft tissue arising in the periarticular space, such as a ganglion cyst, can cause compression of adjacent nerve fascicles passing in the nearby joint space. Intraneural ganglion cysts involving the cranial nerves are particularly rare, with only a few previous cases reported in the literature.

The medial safe zone for treating intraneural ganglion cysts in the tarsal tunnel: a technical note

INTRODUCTION

Intraneural ganglion cysts in the tarsal tunnel are rare but are being increasingly reported. The cysts involve the tibial or plantar nerves and are most commonly derived from a neighboring (degenerative) joint, (i.e., the tibiotalar or subtalar) via an articular branch arising from the medial aspect of the nerve. We describe a safe zone for approaching these cysts in the tarsal tunnel that allows for identification of the joint connection without injury to important distal branches.

METHODS

We present a case of an intraneural ganglion cyst within the tarsal tunnel in a patient with symptoms consistent with tarsal tunnel syndrome. Using intraoperative photographs and artist rendering, we describe a technique to safely disconnect the abnormal joint connection while preserving the important distal branches of the tibial nerve.

CONCLUSION

The safe zone for the tibial nerve in the tarsal tunnel can be exposed by mobilization and gentle retraction of the vascular bundle. In cases of intraneural ganglion cysts, all apparent connections between the nerve and degenerative joints within this safe zone can be resected without injury to important distal nerve branches.

Intraneural Synovial Cyst of the Common Peroneal Nerve: An Unusual Cause of Foot Drop with Four-Year Follow-Up

In our case report, we describe a 55-year-old male patient with isolated foot drop due to an intraneural synovial ganglion. We successfully treated the lesion with decompression via epineurotomy combined with primary division of the recurrent articular branch of the common peroneal nerve (CPN). Compression neuropathies of the common peroneal nerve arise from a variety of causes. Intrinsic compression due to intraneural ganglion cysts of the CPN is rare. Previous reports of simple decompression of the cystic fluid have resulted in recurrence. The unified articular theory describes a pathway for fluid to fill from the proximal tibiofibular joint into the CPN via a recurrent articular branch. In our case, we divide this articular branch which we feel prevents recurrence.

Surgical Treatment of Intraneural Ganglion Cysts of the Ulnar Nerve at the Elbow: Long-Term Follow-up of 9 Cases

BACKGROUND

Intraneural ganglion (IG) cysts have been considered curiosities and their pathogenesis remains controversial.

OBJECTIVE

To clarify ulnar nerve at the elbow (UNE) pathogenesis and long-term surgical outcomes by presenting 9 rare cases of IG of the UNE.

METHODS

Surgical treatment of IG was performed. Clinical symptoms, physical examinations, and electromyogram were evaluated pre- and postoperatively. At least 4 yr of follow-up was performed.

RESULTS

The Tinel's sign became negative and local elbow pain disappeared in all 9 patients after surgery, and the average visual analog scale/score dropped from 4.9 (3-8) to 0 (0-0) after 6.2 d (2-10) on average. Two patients retained positive Froment test, “claw hand” and paresthesias with the 2-point discrimination much different from the contralateral little finger. Postoperative the UK Medical Research Council muscle strength score (MRC) grades of the flexor carpi ulnaris and the flexor digitorum profundus muscle of the fourth and fifth digits recovered to M4-M5 from M0-M2 in all 9 patients. The postoperative MRC grades of the third to fourth lumbrical muscles, the interossei, and the hypothenar recovered to M3-M5 from M0-M2 in 7 patients. Cystic articular branch (CAB) was found in all 9 patients intraoperatively. No symptomatic recurrence of IG was seen. The mean motor nerve conduction velocity of ulnar nerve across the elbow recovered from 5.3 to 41.2 m/s.

CONCLUSION

A unifying articular theory is responsible for the pathogenesis of IG of UNE and disconnection of the CAB would prevent recurrence. The long-term outcome is good after surgical treatment of IG of UNE.

A Case Report and Literature Review: Intraneural Ganglion Cyst Causing Tarsal Tunnel Syndrome

Intraneural ganglion cysts are benign mucinous lesions that form within joints and enter adjacent nerves via an articular branch. Despite being morphologically characterized as benign, they can demonstrate considerable intrafascicular destruction and expansion, resulting in worsening compressive neuropathies or nerve injury. There have been several suggested theories of pathogenesis, but the most widely accepted articular (synovial) theory describes a capsular defect in a neighboring joint that allows joint fluid to egress and track along the epineurium of the innervating articular branch. In this case report, we describe an intraneural ganglionic cyst located in the tarsal tunnel with extensive involvement of the tibial nerve. We describe the symptoms, diagnosis, and treatment as well as review the current literature on intraneural ganglionic cysts.

Ulnar intraneural cysts as a cause of cubital tunnel syndrome: presentation of a case and review of the literature

INTRODUCTION

Intraneural cysts usually involve the common peroneal nerve, and in many cases, they are causing symptoms due to neural compression. It is hypothesized that these cysts originate from the adjacent joints while articular pathology is a major contributing factor for the formation of these lesions. Although ulnar nerve is the second most commonly affected nerve, these lesions usually develop distally at the Guyon tunnel, so cubital tunnel syndrome due to epineural cysts is very rare. In such cases, elaborate preoperative work-up is mandatory and surgical treatment should follow certain well-defined principles.

CASE DESCRIPTION

A 60-year-old female patient presented with complaints of pain along the medial side of her elbow, forearm and hand and a tingling sensation in the same distribution for the past 2 months. The patient had sustained an injury 15 years ago, and a distal humerus fracture was diagnosed at that time. Radiological signs of posttraumatic elbow arthritis were evident at the initial evaluation. The patient was diagnosed with cubital tunnel syndrome which was further confirmed by nerve conduction studies, and she underwent surgical decompression of the nerve. During surgery, intraneural cysts were identified and addressed by excision, while dissection of the articular branch of the nerve was also performed. Pain and numbness subsided shortly after surgery, while the patient remained free of symptoms until the last follow-up.

Intra-neural ganglion cyst of the lateral dorsal cutaneous nerve: an uncommon cause of lateral ankle pain

INTRODUCTION

An intra-neural ganglion cyst of the lateral dorsal cutaneous branch of the sural nerve is rare, with only a few cases reported in the literature.

MATERIALS AND METHODS

We carried out a retrospective investigation of patients with an intraneural ganglion cyst of the lateral dorsal cutaneous nerve.

RESULTS

We present a case series of four patients with intra-neural ganglion cysts of the lateral dorsal cutaneous nerve, the distal continuation of the sural nerve at the lateral aspect of the foot.

CONCLUSION

Intra-neural ganglion cysts of the lateral dorsal cutaneous nerve are rare. They represent a relatively uncommon source of lateral ankle pain, which can easily be diagnosed with ultrasound (US) and magnetic resonance imaging and managed effectively with US-guided aspiration or surgical excision.

Cystic Adventitial Disease of the Tibial Vein Arising From the Subtalar Joint: A Case Report

Soft tissue ganglion cysts are a well-known cause of tibial nerve compression in the tarsal tunnel. We describe a patient who presented with tibial nerve symptoms and was found to have an adventitial cyst of the tibial vein arising from the subtalar joint, with the joint connection confirmed both on imaging and at surgery. Surgical decompression of the cyst with transection of the vascular pedicle arising from the subtalar joint improved her symptoms at 6 months, and postoperative magnetic resonance imaging showed resolution of the cyst. Cystic adventitial disease is a rare, poorly understood condition in which a cyst is identified in the adventitia of a vessel, usually an artery. Only 3 cases of adventitial cysts have been reported in the foot and ankle region, 2 in the lesser and 1 in the greater saphenous vein. None of the previous cases have been recognized to be joint connected. This case provides additional evidence for an articular origin for adventitial cysts and helps guide management strategies for these joint-connected cysts.

Superficial radial intraneural ganglion cysts at the wrist

Superficial radial intraneural ganglion cysts are rare. Only nine previous cases have been described. We provide two examples with a wrist joint connection and review the literature to provide further support for the unifying articular (synovial) theory for the pathogenesis and treatment of intraneural ganglia.

Retracing the observations and footsteps of Beauchêne fils: A blueprint for scientific research

Throughout the years, scientific and personal research has led us on a historical journey to learn about the life of Beauchêne fils (Edme François Chauvot de Beauchêne), a French clinical anatomist, prosector, and surgeon responsible for introducing the disarticulated skull technique and the first citation of an intraneural cyst. This letter describes our research, travels, and conversations intended to uncover the fascinating history of Beauchêne fils and his family and our journey full of unexpected twists and turns. During a trip to Paris, we learned of a possible inspiration for the disarticulated skull technique from skulls afflicted with la teigne (Tinea corporis, ring worm) at the Musée Dupuytren. We toured the estate of his family's summer home in Paron, France, where we discovered a portrait of Beauchêne fils' father that had been misidentified in our recent publication. We also discovered the date of death and elusive burial site of Beauchêne fils in Père Lachaise cemetery in Paris. We hope to bring to light the life and contributions of a nearly unknown figure who influenced not only research on intraneural ganglion cysts and the articular theory, but also the future of the field of anatomy. Clin. Anat. 31:1194-1198, 2018. © 2018 Wiley Periodicals, Inc.