Ultrasound-Guided Release of the Tibial Nerve and Its Distal Branches: A Cadaveric Study.

OBJECTIVES: The purpose of the study was to determine whether ultrasound (US)-guided surgery is a viable type of surgery for performing an effective release/decompression of the constricting structures that are responsible for focal nerve compression in tarsal tunnel syndrome. METHODS: Ultrasound guidance was used on cadaveric specimens to delineate the anatomic course of the nerves and vessels in the medial ankle that comprise the structures involved in tarsal tunnel syndrome. Ultrasound guidance was used on cadaveric specimens and assisted in delineating a safe surgical zone to adequately and effectively release these constrictive structures of the proximal and distal tarsal tunnels. The US-guided tarsal tunnel release/decompression was performed through 2 small 1- to 2-mm portals. After US-guided release, anatomic dissection was used to check the efficacy (release of the flexor retinaculum and deep abductor hallucis muscle) and safety (absence of neurovascular or tendon injury) of the procedure. RESULTS: In 12 fresh cadaveric specimens, US-guided release of the tibial nerve (proximal tarsal tunnel) and its branches (distal tarsal tunnel) at the medial ankle was effective in all 12 specimens (100% release rate), without any signs of compromise or injury into the neurovascular structures. CONCLUSIONS: Ultrasound-guided tarsal tunnel release is a feasible surgical procedure that can be safe and effective with the proper training, although further investigation is warranted. This type of surgery may promote faster recovery with less postoperative morbidity, including pain, but this will be the subject of a further investigation.

Anatomic Delineation of Tarsal Tunnel Innervation via Ultrasonography.

OBJECTIVES: High-resolution ultrasonography (US) can play an important role in studying nerves, as it has several advantages. Entrapments of distal tibial nerve branches can be mapped out or diagnosed with selective anesthetic blocks, and US can guide therapeutic procedures, such as radiofrequency ablation and selective infiltrations of specific nerve branches. The aim of this study was to verify that US is an effective method for accurately locating the posterior tibial nerve and its terminal branches, such as the medial calcaneal branch, the first calcaneal branch, and the medial and lateral plantar nerves. METHODS: In this study, we analyzed the correlation between US mapping and real anatomy after cadaveric dissection, assessing the distribution and variability of the tibial nerve and its terminal branches. We used 12 fresh anatomic specimens of the foot and ankle, including the calf. A high-resolution US study of the tibial nerve and its branches was performed. RESULTS: The results of the US studies of the anatomic specimens were drawn as paper diagrams and in data collection tables. Both were completed twice per anatomic specimen, first using the results of the US study and second using the results from dissection of the anatomic specimens; this approach enabled us to compare the results and verify whether the US study and the dissection correlated on the topography of the tibial nerve and its terminal branches. We found almost total agreement between the US and dissection results, with no significant differences between the evaluations. CONCLUSIONS: On the basis of this work, we can conclude that high-resolution US is almost 100% effective as a tool for identifying the tibial nerve and its branches, enabling the specialist to make diagnoses or perform selective treatments on each nerve branch and even to design surgical interventions by observing the patient's anatomy before performing the dissection.

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

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

Endoscopic plantar fasciotomy: preliminary study with cadaveric specimens. 1991.

The authors have developed an endoscopic approach to a plantar fasciotomy. This technique would minimize the surgical trauma that is normally induced with a conventional type of heel spur surgery. The authors believe that this new technique will provide an earlier return to normal ambulation, less loss of work, and earlier, overall increased patient comfort.

Comment on IWGDF ulcer prevention guidelines.

The IWGDF 2019 Updated Guidelines for prevention of foot ulcers in diabetes advise that nerve decompression surgery not be considered. This nerve decompression option has similar scientific supporting evidence to other surgeries which are recommended. The sanction ignores a large body of non-Level 1 evidence demonstrating various beneficial outcomes of ND including pain relief, DFU prevention, and protection from recurrence and amputation.

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

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

Midarch Foot Pain: Entrapment Neuropathy of the Distal Medial Plantar Nerve and Its Branches.

Medial forefoot pain, or midarch pain, is usually attributed to plantar fasciitis. The authors present their findings of a previously unreported nerve entrapment of the medial proper plantar digital nerve (MPPDN). Ten fresh-frozen cadaveric specimens were analyzed for anatomical variance in the nerve distribution of the MPPDN. In addition, clinical results from a retrospective review of nine patients who underwent surgical nerve decompression of the MPPDN are presented. Significant anatomical variance was found for the MPPDN in the cadaveric dissection of 10 fresh-frozen specimens. Nine patients with a clinical diagnosis of entrapment of the MPPDN all obtained excellent pain relief with surgical external neurolysis. Only one complication occurred: a hypertrophic scar formation that was successfully treated with intralesional steroid injections. The authors believe that this MPPDN entrapment is often overlooked or misdiagnosed as plantar fasciitis. Surgical peripheral nerve decompression of this nerve can provide positive outcomes for patients suffering from midarch foot pain caused by this pain generator.

Historical development of bipolar coagulation.

In 1926, a physicist at Harvard named William T. Bovie created an instrument, which revolutionized the medical profession--the unipolar electrocautery device. This incredible device could make surgical incisions and provide hemostasis as well. It came with a price, however, as it also created new risks and dangers in the operating room, such as electrical burns and fires. To resolve some of these problems, a bipolar electrocautery device was developed. The historical development and principles of both unipolar and bipolar electrocautery will be discussed in this article.

Ultrasound-Guided Decompression of the Intermetatarsal Nerve for Morton's Neuroma: A Novel Closed Surgical Technique.

BACKGROUND: This study describes the technique for decompression of the intermetatarsal nerve in Morton's neuroma by ultrasound-guided surgical resection of the transverse intermetatarsal ligament. This technique is based on the premise that Morton's neuroma is primarily a nerve entrapment disease. As with other ultrasound-guided procedures, we believe that this technique is less traumatic, allowing earlier return to normal activity, with less patient discomfort than with traditional surgical techniques. METHODS: We performed a pilot study on 20 cadavers to ensure that the technique was safe and effective. No neurovascular damage was observed in any of the specimens. In the second phase, ultrasound-guided release of the transverse intermetatarsal ligament was performed on 56 patients through one small (1- to 2-mm) portal using local anesthesia and outpatient surgery. RESULTS: Of the 56 participants, 54 showed significant improvement and two did not improve, requiring further surgery (neurectomy). The postoperative wound was very small (1-2 mm). There were no cases of anesthesia of the interdigital space, and there were no infections. CONCLUSIONS: The ultrasound-guided decompression of intermetatarsal nerve technique for Morton's neuroma by releasing the transverse intermetatarsal ligament is a safe, simple method with minimal morbidity, rapid recovery, and potential advantages over other surgical techniques. Surgical complications are minimal, but it is essential to establish a good indication because other biomechanical alterations to the foot can influence the functional outcome.

Computerized analysis of plantar pressure variation in flip-flops, athletic shoes, and bare feet.

BACKGROUND: High peak plantar pressures predispose to foot problems and may exacerbate existing conditions. For podiatric physicians to make educated recommendations to their patients, it is important and necessary to begin to look at different shoes and how they affect peak plantar pressure. METHODS: To determine how flip-flops change peak plantar pressure while walking, we compared peak plantar pressures in the same test subjects wearing flip-flops, wearing athletic shoes, and in bare feet. Ten women with size 7 feet and a body mass index less than 25 kg/m2 were tested with an in-shoe pressure-measurement system. These data were collected and analyzed by one-way analysis of variance and computer software. RESULTS: Statistically significant results were obtained for nine of the 18 comparisons. In each of these comparisons, flip-flops always demonstrated higher peak plantar pressures than athletic shoes but lower pressures than bare feet. CONCLUSION: Although these data demonstrate that flip-flops have a minor protective role as a shock absorber during the gait cycle compared with pressures measured while barefoot, compared with athletic shoes, they increase peak plantar pressures, placing the foot at greater risk for pathologic abnormalities.

Endoscopic decompression of intermetatarsal nerve entrapment: a retrospective study.

Sixty-nine patients who had 96 interspaces decompressed were retrospectively reviewed to assess the efficacy of the endoscopic decompression of the intermetatarsal nerve procedure. Cases were evaluated between October 1, 1993, and December 31, 1999. Of the 69 patients, 14 were men and 55 were women, and their average age was 50.6 years. Of the 96 interspaces released, 39 were second interspaces and 57 were third interspaces. Nine interspaces were lost to follow-up. There were 75 interspaces with excellent or good results (86%) and 12 with poor results (14%). Of the interspaces with poor results, five required further surgery. Those five interspaces, in five patients, were treated with traditional neurectomy. The other patients, accounting for seven interspaces, who classified their result as poor declined any further surgery. Evaluation of these cases was by means of medical chart review only, where the patient's success or failure was based on the patient's subjective assessment. None of the patients who underwent decompression developed a true amputation neuroma.

Endoscopic nerve decompression.

Endoscopic decompression for forefoot nerve entrapments is discussed in this article from not only the perspective of preoperative indications, intraoperative technique, and postoperative management, but with reference to the changing paradigm for management of this condition. Surgical results are discussed and compared with other published reports. Complications of the surgical technique are also discussed, which will give the operating surgeon a frame of reference when comparing decompression procedures to those techniques involving nerve resection. There is also a valuable discussion of current methods of diagnosis that may help the practitioner improve patient outcomes.

Case Study: Osseous Pathology with Peripheral Nerve Entrapment and Neuromata.

This case illustrates the complexity and interrelationship of osseous pathology with peripheral nerve entrapment and neuromata. She had an iatrogenic nerve injury of a branch of the medial dorsal cutaneous nerve causing her painful scar. Secondarily, she developed an injury to her common peroneal nerve from the cast immobilization, resulting in palsy/drop foot. The tarsal tunnel entrapment was likely a sequela of the cast immobilization and chronic swelling. Her postoperative chronic pain was compounded by the failure to use grommets with the polymeric silicon (Silastic) implant at the initial surgery, leading to a breakdown of the implant with subsequent detritic synovitis.

Small Fiber Neuropathy: Differential Diagnosis and Treatment Implications.

Burning sensation in the feet is a common problem encountered in podiatric medicine. When this pain is bilateral, symmetric, and includes the top and bottom of both feet, small nerve fiber involvement must be considered in the differential diagnosis. With the now available, in-office, skin biopsy quantification of intraepidermal nerve fibers, documentation of the presence of small fiber involvement in the pain mechanism is possible. Technical details of performing the skin biopsy are reviewed and the legal implications of a positive abnormal skin biopsy for intraepidermal nerve fibers is discussed.

Sinus tarsi denervation: clinical results.

Traumatic neuroma of the branches of the deep peroneal nerve that innervate the sinus tarsi can be the source of recalcitrant lateral ankle pain. That these nerves can be the source of the pain can be demonstrated by nerve blocks, and this pain can be surgically treated by resection of the appropriate branch of the deep peroneal nerve. This article documents the clinical results of this approach in 13 patients with sinus tarsi syndrome. At a minimum of 6 months postoperatively, 10 patients (77%) were completely pain-free, wore normal shoes, and had returned to work. Two patients (15%) had a small degree of residual pain but resumed usual activities and wore normal footwear. One patient had some pain relief but could not resume usual activities. We conclude that denervation of the sinus tarsi can relieve recalcitrant pain emanating from the sinus tarsi. This approach may reduce the need for subtalar fusion or evacuation procedures, including arthroereisis, thus avoiding their potential complications. Moreover, sinus tarsi denervation may allow the continued use of an arthroereisis implant in the presence of satisfactory objective findings, despite the subjective presence of postoperative pain.

Use of high-resolution ultrasound in evaluation of the forefoot to differentiate forefoot nerve entrapments.

Forefoot pain can have single or multiple etiologies, and frequently pain is attributed solely to a forefoot nerve entrapment. It is well known that forefoot nerve entrapments, such as Morton's, can be falsely assumed to be the cause of forefoot pain when in fact other factors, such as plantar plate disturbances, are the true cause. Frequently, the cause of the patient's forefoot pain starts as a forefoot nerve entrapment, but then, as a result of treatment with a corticosteroid injection, other pathologies manifest, such as plantar plate rupture. The development of high-resolution, high-frequency ultrasound scanners has opened the door to in-depth examination of peripheral nerves as well as small pericapsular and intracapsular joint structures of the foot and ankle. In the hands of an experienced clinician, ultrasound can play an important role in differentiating nerve lesions and entrapment syndromes from nonneurogenic pain generators, such as tendons, ligaments, fasciae, and joint capsules. The focus of this article is the forefoot, where differentiation of neuroma, neuritis, and capsulitis can be difficult.

Equinus deformity as a factor in forefoot nerve entrapment: treatment with endoscopic gastrocnemius recession.

Forefoot nerve entrapments are common, and they are usually mistakenly categorized under the misnomer of "Morton's neuroma." Although the complete etiology of these forefoot entrapments is still not known, exogenous mechanical factors must be considered when patients present with clinical signs of forefoot nerve entrapment. It has been well established that equinus deformity can increase plantar forefoot pressures. This article provides a brief overview of equinus deformity as it relates to forefoot pathology, specifically, its mechanical contribution to forefoot nerve entrapment, and the use of endoscopic gastrocnemius recession for the treatment of forefoot nerve entrapment.

Accurate nomenclature for forefoot nerve entrapment: a historical perspective.

Current medical nomenclature is often based on the early history of the condition, when the true etiology of the disease or condition was not known. Sadly, this incorrect terminology can become inextricably woven into the lexicon of mainstream medicine. More important, when this is the case, the terminology itself can become integrated into current clinical decision making and ultimately into surgical intervention for the condition. "Morton's neuroma" is perhaps the most striking example of this nomenclature problem in foot and ankle surgery. We aimed to delineate the historical impetus for the terminology still being used today for this condition and to suggest appropriate terminology based on our current understanding of its pathogenesis. We concluded that this symptom complex should be given the diagnosis of nerve compression and be further distinguished by naming the involved nerve, such as compression of the interdigital nerve to the third web space or compression of the third common plantar digital nerve. Although the nomenclature becomes longer, the pathogenesis is correct, and treatment decisions can be made accordingly.

Perioperative posterior heel pain caused by multiple etiologies including a neuroma in continuity of the posterior branch of the sural nerve: a case report.

Posterior heel pain after a prior Haglund's deformity surgical correction can be resultant to multiple etiologies: osseous, tendinous, and neural. In this case report, all three potential etiologies were found to be contributing to the postoperative status of the patient. This case report illustrates identification and treatment of a neuroma in continuity of the posterior branch of the sural nerve with preservation of the sural nerve itself via microdissection, which we believe has not been described previously in the literature.