Ulnar Wrist Denervation: Articular Branching Pattern and Selective Blockade of the Dorsal Branch of the Ulnar Nerve.

PURPOSE: Ulnar wrist denervation has been a successful treatment for patients with ulnar-sided wrist pain. The purpose of this study was to characterize the articular branches of the dorsal branch of the ulnar nerve (DBUN) and validate a technique for selective peripheral nerve blockade. METHODS: In cadavers, we performed simulated local anesthetic injections using 0.5 mL of 0.5% methylene into the subcutaneous tissue at a point midway between the palpable borders of the pisiform and ulnar styloid. We then dissected the DBUN, characterized its articular branching pattern, and measured staining intensity of the DBUN and the ulnar nerve relative to a standard. RESULTS: The DBUN branched from the ulnar nerve 7.0 ± 1.2 cm proximal to the ulnar styloid. Among 17 specimens, the DBUN provided an average of 1.2 (range, 0-2) ulnocarpal branches and 1.0 (range, 0-2) carpometacarpal articular branches. A simulated local anesthetic injection successfully stained 100% of the DBUN articular branches at or proximal to their takeoff. There was no staining of the proper ulnar nerves. In all specimens, the DBUN supplied at least one articular branch. CONCLUSIONS: A point midway between the palpable border of the pisiform and ulnar styloid may be an effective location for selectively blocking the DBUN articular afferents. CLINICAL RELEVANCE: In this study, we were able to identify a point halfway between the pisiform and ulnar styloid that has the potential to produce a selective peripheral nerve block of the portion of the DBUN that supplies articular fibers to the ulnocarpal joint and the fifth carpometacarpal joint. This technique may prove useful to surgeons treating ulnar-sided wrist pain.

Relief of Sitting Pain by Resecting Posterior Femoral Cutaneous Nerve, and Elucidation of Its Anatomical Branching Pattern.

BACKGROUND: Injury to the posterior femoral cutaneous nerve (PFCN) produces sitting pain in the buttock, posterior thigh, and/or the ischial tuberosity. The anatomy of the PFCN has not been well described, and just one small cohort of patients has been reported to have resection of the PFCN. METHODS: Retrospective review of all patients undergoing resection of the PFCN for sitting pain by the senior author between 2012 and 2019 was performed. Evaluation was done by chart review, intraoperative description of the anatomy of the PFCN, and the outcome of resection of the PFCN with implantation of the proximal nerve into the gluteus muscle. Outcome was determined by direct patient examination, email reports, and telephonic interview. RESULTS: Fifty-two patients were included in this study, of which nine were bilateral operative procedures. Thirty-four patients had sufficient follow-up data at a mean of 23 months (3-85 months, range). MRI evidence of hamstring injury was present in 50% of the patients. The classic PFCN anatomy was present in 44% of limbs with the other 56% having a high division permitting branches to the lateral buttock and posterior thigh to be preserved. In patients with bilateral anatomy observations, symmetry was present in 67%. An excellent result (absence of sitting pain, normal activities of daily living [ADL]) was obtained in 53%, a good result (some residual sitting pain with some reduction in ADL), was obtained in 26% and no improvement was observed in 21% of patients. CONCLUSION: Sitting pain due to injury to the PFCN can be relieved by the resection of the PFCN with implantation of the proximal end into muscle. Presence of an anatomical variation, a high division of the PFCN, can permit preservation of sensation in the lateral buttock and posterior thigh in the patient whose symptoms involve just the perineum and ischial tuberosity.

Risk Factors Associated With the Progression From Acute to Chronic Neuropathic Pain After Burn-Related Injuries.

BACKGROUND: Pain, unrelated to the initial thermal trauma itself, can result after burn injury and prolong the recovery/rehabilitation phase of the patient's care. This pain, after discharge from the burn unit, may be acute and self-limiting or chronic and contribute to long-term patient morbidity. The purposes of this study were to compare burn patients who had, after discharge from the burn unit, only acute pain with burn patients who developed chronic, neuropathic pain (CNP) and to determine risks factors for progression from acute to chronic pain in the setting of a burn center. METHODS: A single-center, retrospective chart review of patients admitted to the adult burn center was performed from January 1, 2014, to January 1, 2019. Patients included were older than 15 years, sustained a burn injury, and admitted to the burn unit. Chronic pain was defined as pain lasting greater than 6 months after discharge from the burn unit. Pain descriptors included shooting, stabbing, sharp, burning, tingling, numbness, throbbing, pruritus, intermittent, and/or continuous dysesthetic sensations after the burn. Patients were excluded if they had preexisting neuropathic pain due to an underlying medical illness or previous surgery. RESULTS: During a 5-year period, of the 1880 admissions to the burn unit, 143 burn patients developed post-initial-onset pain as a direct result of their burn. Of the 143 patients with acute pain, pain resolved in 30 patients, whereas pain progressed to CNP in 113 patients (79%). Patient follow-up was a median (interquartile range [IQR]) of 26.5 (10-45) months. Patients whose pain progressed to CNP had significantly greater percent total body surface area burns (median [IQR], 6 [3-25] vs 3 [1-10]; P = 0.032), had more full-thickness burns (66/113 [58%] vs 8/30 [27%] patients, P = 0.004), had surgery (85/113 [75%] vs 16/30 [53%] patients, P = 0.042), had more surgical procedures (median [IQR], 2 [1-6] vs 1 [0-3], P = 0.002), and developed more complications (32/113 [28%] vs 2/30 [7%] patients, P = 0.014) compared with those with acute neuropathic pain, respectively. CONCLUSIONS: Burn patients who progressed from having acute to CNP had significantly greater percent total body surface area burns, had more full-thickness burns, had surgery, had more surgical procedures, and developed more complications compared with burn patients with only acute pain.

Bladder Pain Syndome/Interstitial Cystitis due to Pudendal Nerve Compression: Described in 1915-A Reminder for Treating Pelvic Pain a Century Later.

Background Interstitial cystitis (IC) or bladder pain syndrome (BPS) is highly painful and disabling and probably the most misdiagnosed urologic condition. Its classic symptoms of perineal pain, urinary urgency, and frequency despite sterile urine cultures were already described more than a century ago in a report on soldiers during World War (WW) I due to chronic pudendal nerve compression. Objectives This article translates a report from 1915 on pudendal neuropathy and discusses its author Georg Zülzer (1870-1949). Methods An English translation of the German original is provided with the biography and work of Zülzer, his clinical observations are discussed regarding modern diagnosis and therapy of pudendal nerve compression. Results In his article entitled "Irritation of the Pudendal Nerve (Neuralgia). A Frequent Clinical Picture during War Feigning Bladder Catarrh," Zülzer describes his observation of soldiers during WW I, presenting with a triad of perineal pain, urinary urgency, and frequency despite sterile urine cultures excluding urinary infections. He also documented a characteristic skin hypersensibility of the perineum in a rhomboid shape which corresponds to the innervation area of the pudendal nerve with its two branches deriving from the "pudendal plexus." He regards this symptomology as rare during peace, but as disease of trench warfare which can be easily diagnosed regarding clear urine and a painful skin island overlying the area of the pudendal nerve as tested by simple needle examination. Zülzer, born in Germany, was forced to emigrate to the United States in 1934, was also an important pioneer of diabetes research using pancreas extracts from dogs as early as 1907. Conclusion In this historical description, dating from about a century ago, Georg Zülzer probably gave the first exact clinical description of symptoms due to pudendal nerve compression. Pudendal nerve compression should always be taken into account when examining and treating patients with symptoms of IC/BPS.

Nikolaus Rüdinger (1832-1896), His Description of Joint Innervation in 1857, and the History of Surgical Joint Denervation.

BACKGROUND: Selective joint denervation has become a reliable palliative treatment, especially for painful joints in the upper and lower extremity. METHODS: This article highlights the life and work of Nikolaus Rüdinger (1832-1896) who first described joint innervation which became the basis of later techniques of surgical joint denervation. The historical evolution of this method is outlined. RESULTS: Rüdinger made a unique career from apprentice barber to military surgeon and anatomy professor in Munich, Germany. His first description of articular innervation of temporomandibular, shoulder, elbow, wrist, finger, sacroiliac, hip, knee, ankle, foot, and toe joints in 1857 stimulated the subsequent history of surgical joint denervation. Comparing his investigations with modern joint denervation methods, developed by pioneers like Albrecht Wilhelm or A. Lee Dellon, shows his great exactitude and anatomical correspondence despite different current terminology. Clinical series of modern surgical joint denervations reveal success rates of up to 80% with reliable long-term results. CONCLUSION: The history of joint denervation with Rüdinger as its important protagonist offers inspiring insights into the evolution of surgical techniques and exemplifies the value of descriptive functional anatomy, even if surgical application may not have been realized until a century later.

Surgical Treatment of Upper Extremity Pain.

If the patient with hand pain remains without significant relief and without recovery of function after appropriate pharmaceutical and physical modality treatments, it is appropriate to consider a surgical approach to the pain. Categories of pain amenable to a surgical approach are pain caused by nerve compression, pain caused by a neuroma, and joint pain of neural origin. Compressed nerve should be decompressed and depending on the intraoperative findings a neurolysis also should be performed. Painful neuroma must be resected to stop the pain generator. For a painful joint, the biomechanics of that joint must first be stable before denervation.

3-Tesla High-Field Magnetic Resonance Neurography for Guiding Nerve Blocks and Its Role in Pain Management.

Interventional magnetic resonance (MR) neurography is a minimally invasive technique that affords targeting of small nerves in challenging areas of the human body for highly accurate nerve blocks and perineural injections. This cross-sectional technique uniquely combines high tissue contrast and high-spatial-resolution anatomic detail, which enables the precise identification and selective targeting of peripheral nerves, accurate needle guidance and navigation of the needle tip within the immediate vicinity of a nerve, as well as direct visualization of the injected drug for the assessment of appropriate drug distribution and documentation of the absence of spread to confounding nearby nerves.

Posttraumatic Midface Pain: Clinical Significance of the Anterior Superior Alveolar Nerve and Canalis Sinuosus.

BACKGROUND: Posttraumatic midface pain secondary to injury of the anterior superior alveolar nerve (ASAN) is characterized as pain localized to the central and lateral incisors, canines, and maxilla. This nerve is susceptible to injury and subsequent formation of neuromas after midface trauma. Surgical intervention requires an accurate and precise understanding of the course of the ASAN. METHODS: Dissections of 12 human cadaver heads were conducted to identify the course of the ASAN through the canalis sinuosus (CS). Fifty 1-mm slice face computed tomographic scans were evaluated to document the dimensions and course of the CS. RESULTS: The ASAN branched laterally from the infraorbital nerve before reaching the infraorbital rim in all cadavers. The bifurcation occurred 18 mm posterior to the infraorbital rim (range, 10-30 mm). At a point 25 mm inferior to the infraorbital rim, the ASAN is found 3.4 mm lateral to the piriform aperture (range, 3-4 mm). Radiographic analysis demonstrated a 12.9-mm horizontal length of the CS across the anterior maxilla (SD, 2.2 mm), a distance of 4.8 mm between the piriform aperture and the CS (SD, 1.2 mm), and 11.7 mm vertical length of the CS along the piriform aperture (SD, 3.0 mm). CONCLUSIONS: The ASAN maintains consistent coordinates at specific points along its course through the midface. An improved understanding of the course of the ASAN will guide future diagnosis of injury to this nerve and surgical intervention for patients with posttraumatic midface pain secondary to ASAN injury.

Sciatic and peroneal nerve injuries after endovascular ablation of lower extremity varicosities: case reports and review of the literature.

Varicose veins have traditionally been treated by surgical intervention. When performed in the lower limb, surgical vein stripping can potentially cause injury to the saphenous, sural, tibial, and peroneal nerves due to anatomic proximity. Newer, minimally invasive procedures, such as endovenous laser ablation and endovenous radiofrequency ablation, are more commonly used today. Although the potential for neural injury is greatly reduced, endovenous laser ablation and endovenous radiofrequency ablation have been documented to cause neural damage. Here, we report rare complications of 2 cases of varicosity endovascular ablation. One case involves ablation of the lesser saphenous vein and resulted in injury to the proximal common peroneal and tibial as well as distal sciatic nerves. The second case involves ablation of the vein of Giacomini that resulted in a common peroneal nerve injury. We stress the importance of preoperative anatomic mapping of the highly variable venous and neural systems in the area of ablation to minimize neural complications.

Surgical treatment of superimposed, lower extremity, peripheral nerve entrapments with diabetic and idiopathic neuropathy.

BACKGROUND: Although it is recognized that people with peripheral neuropathy have an increased prevalence of chronic nerve entrapment, controversy still exists over their management. The present report details the evaluation, surgical approach, and outcome of a large cohort of people with diabetic and with idiopathic neuropathy. METHODS: A retrospective review of 158 consecutive patients, 96 with diabetic and 62 with idiopathic neuropathy, was done to analyze the results of neurolysis of multiple sites of chronic nerve compression in the lower extremity. Of these patients, 50 had a contralateral limb decompressed for a total of 208 limbs included in the study. Outcomes included visual analog scale (VAS) for pain in the 109 patients who had pain level greater than 8.0, measurement of the cutaneous pressure threshold for sensibility, self-reported change in pain medication usage, and self-reported change in balance. RESULTS: With a minimum follow-up of 1 year, 88% of patients with preoperative numbness reported improvement in sensation (P < 0.001). Of the 84 patients with impaired balance, 81% reported improvement in balance. Of those whose VAS was greater than 8, 83% reported an improvement in VAS (P < 0.001). There was a concomitant reduction in pain medication usage. There was no difference in outcomes between patients with diabetic versus idiopathic neuropathy in response to nerve decompression. CONCLUSIONS: Neurolysis of lower extremity chronic nerve compressions in patients with neuropathy and superimposed nerve compressions is an effective method for relieving pain, restoring sensation, and improving balance.