Guyon's Canal Research Articles

Prospective outcome analysis of ulnar tunnel syndrome: Comparing traumatic versus non-traumatic etiologies

Ulnar tunnel syndrome (UTS) is relatively uncommon compared to the carpal tunnel or cubital tunnel syndromes. Few reports dedicated to the functional outcomes after surgical intervention of the UTS exist. Herein we compare the outcomes of patients with UTS of different etiologies. Patients diagnosed with UTS between 2016 and 2020 were recruited. Ulnar tunnel release was performed in all patients, along with other necessary osteosynthesis or reconstructive procedures in the traumatic group. Patients were followed-up every six months post-operatively. Outcomes measured include: objective evaluations, subjective questionnaires, records of clinical signs, and grading of the British Medical Research Council scale for intrinsic muscle strength. 21 patients were recruited, and favorable results were noted in all of them after surgery. Traumatic UTS patients had a worse initial presentation than the non-traumatic cases, but had a greater improvement after surgery and yielded outcomes comparable with those of the patients without trauma. Patients with aberrant muscles in their wrists had better outcomes in some objective measurements than those without aberrant muscles. Ulnar tunnel release improves the outcome of patients regardless of the etiology, especially in patients with trauma-induced UTS. Thus, a proper diagnosis of the UTS should be alerted in all patients encountering paresthesia in the ulnar digits, ulnar-sided pain, weakness of grip strength, or intrinsic weakness to ensure good outcomes.

Medial Ulnar Collateral Ligament Reconstruction: A Dual Docking, 4-Ply Reconstructive Technique

Background: Ulnar collateral ligament injuries are common in the overhead-throwing athlete as the anterior band of this ligament is the primary soft tissue static stabilizer to valgus stress during a throwing motion. Various surgical techniques have been described over the past 30 years to address these injuries including Jobe, modified Jobe, docking, 3-stranded docking, Graftlink, and anatomic repairs with good to excellent results. Nevertheless, modifications to these techniques may increase the strength and survival of the reconstruction, which may expedite and optimize postoperative rehabilitation and return to play. Indications: This is a reproducible technique that provides excellent outcomes. We believe a 4-ply construct, with the addition of a high tensile strength suture tape, may provide superior biomechanical properties compared to other reconstructive techniques. Biomechanical testing for this technique is currently underway. Technique Description: Medial ulnar collateral ligament reconstruction using a gracilis autograft passed from proximal to distal, secured at the ulna with a cortical button tension loop construct, and then repassed from distal to proximal with the addition of a high strength suture in parallel to function as an internal brace. Together, this creates a reinforced, 4-ply, ulnar collateral ligament reconstruction with excellent tensile strength. Other advantages of this technique are that it avoids bony bridge fracture between ulnar tunnels, it preserves ulnar bone stock, creates a more anatomic insertion at the sublime tubercle and provides a simple method to tension the entire graft construct. Results: The expected outcomes from this procedure are consistently positive with recent literature reporting greater than 90% of patients having an excellent outcome and over 80% of overhead athletes returning to sport at or above previous level. Conclusion: This specific technique provides a rigid, high-tensile strength reconstruction with excellent outcomes and a high percentage of return to play. Additionally, this technique avoids various technical pitfalls by utilizing cortical button suspensory fixation at the ulna which minimizes complications such as ulnar tunnel conversion and iatrogenic injury to the ulnar nerve when drilling posterior to the sublime tubercle as is necessary with other techniques.

New approaches to the diagnosis and surgical treatment of tunnel syndromes of the upper limb

The purpose of the work was to evaluate the modern methods of diagnosis that determined the state of vegetative fibers, tunnel morphology, and surgical treatment of tunnel syndrome. There were 30 healthy individuals (control group) and 45 patients (16 with compression of the ulnar nerve in the zone of cubital canal, 27 with carpal canal syndrome and median nerve compression and 2 patients with Guyon canal syndrome). Clinical-roentgenologic methods, electroneuromyography (ENMG), ultrasonography, computer tomography, Lazer Doppler flowmetry (LDF), ultrasound dopplergraphy of wrist were used. The diagnosis of tunnel syndromes is based on a through clinical-roentgenologic and instrumental evaluation of the nerve trunk fibers function. Not only ENMG with assessment of the sensor and motor innervation is expedient but the evaluation of the neurogenic LDF indices stipulated by sympathic fibers as well. Auxiliary diagnostic method is ultrasonography of tunnel zone which provides information on the morphology of the canal structures, topography and general sizes of the nerves in the compression zone. All patients underwent surgical intervention for the decompression of nerve trunks. It is for the first time that the method of endoscopic dissection of the carpal ligament has been used at our clinic in 7 patients with early stages (I-II) of the disease. Endoscopic method of carpal canal syndrome treatment is an effective and lower invasive intervention that allows to restore the working ability of patients with early stages of the process in a short time.

A Comparison of the Outcomes of Excision of the Fractured Hook of Hamate via a Carpal Tunnel Approach versus a Lateral Approach.

Background: The excision of the hook of the hamate is an accepted modality for the treatment of hook of hamate fractures. Three surgical approaches to the hook of hamate have been described in literature. This includes two palmar approaches namely the Guyon canal approach and the carpal tunnel approach, and the lateral approach. The aim of this article is to compare the outcomes of the carpal tunnel approach and the lateral approach. Methods: Twenty-four patients with hook of hamate fractures were treated by excision of the hook of hamate. The hook of hamate was approached via the carpal tunnel in 15 patients and via the lateral approach in 9 patients. The outcomes with regard to duration of the surgery, complications such as pain, sensory disturbance and scar problems and time to return to sports were measured and analysed. Results: There were no significant differences in outcomes between the carpal tunnel and the lateral approach for excision of hook of hamate fractures. Conclusions: The outcomes of excision of the hook of hamate via the carpal tunnel approach and the lateral approach are similar. The decision to choose an approach should be based on the surgeon's familiarity with the approach. Future studies should include a comparison with the Guyon canal approach preferably in a homogenous group of patients. Level of Evidence: Level IV (Therapeutic).

Unexplored parameters of ulnar nerve in the palm and its clinical implications; A cadaveric study

ObjectivesSeveral studies have been conducted on the variations and branching pattern of the ulnar nerve in the hand. There are few studies conducted on defining the distance of ulnar nerve from bony landmarks in the palm. Ulnar nerve is closely related to the pisiform and hook of hamate which act as important landmarks. MethodsThe study was conducted on 30 formalin fixed adult hand specimens in the department of Anatomy. Various measurements related to the ulnar nerve in the palm were taken using a divider and Vernier Calipers and the values were tabulated after obtaining the mean and standard deviation. ResultsThe average distance seen in the hand specimens [n = 30] from pisiform to the division of ulnar nerve into superficial and deep branch was 0.89 ± 0.25cm and the distance between pisiform bone up to the division of superficial branch of ulnar nerve into proper and common digital branches was 1.36 ± 0.59 cm. The average distance from the origin of proper digital branch of ulnar nerve to the head of fifth metacarpal bone was 5.25 ± 0.59 cm. The length of common digital branch of ulnar nerve from its origin to division into 2 sensory branches was 4.31 ± 1.09 cm. ConclusionThis study provides the metric parameters of the ulnar nerve in the hand from its significant bony landmarks which should be kept in mind during surgical procedures to minimize the incidence of injury to its branches. It would assist the orthopedic surgeon in the treatment of ulnar nerve compression in the Guyon's canal.

Guyon canal syndrome after endoscopic carpal tunnel release (ECTR): A case report

Guyon canal syndrome after endoscopic carpal tunnel release (ECTR): A case report

Musicians’ medicine – potential health problems among violinists and violists caused by playing the string instrument – the review of the literature

Introduction and purpose
 Musicians' medicine has received increasing attention recently. It is known that listening to music or playing an instrument has beneficial effects on cognitive and neural functions. Playing the string instrument demands repetitive precise movements of fingers and arms in a non-ergonomic posture that might give rise to health problems.
 The study aims to present the current state of knowledge regarding different potential health problems among violinists and violists. The article reviews the 24 newest scientific publications available on PubMed and Google Scholar.
 A brief description of the state of knowledge
 The literature review indicated several potential health consequences of excessive playing the violin or viola, as follows: Fiddler's neck and skin allergy, Garrod’s pads, temporomandibular disorders, carpal tunnel syndrome, cubital tunnel syndrome, tennis elbow, compression of the right ulnar nerve in the ulnar (Guyon's) canal, rotator cuff tendonitis, tenosynovitis, bursitis, focal dystonia, thoracic outlet syndrome, bone asymmetry, pain in the neck, cheeks, fingers, wrist, forearm, shoulder, waist, and the back.
 Conclusions 
 Musicians should be aware of potential health problems that occur during prolonged playing the violin or the viola. An important issue is maintaining the accurate proportions between the amount of time spent playing the instrument and resting. The first signs of neurological or musculoskeletal changes should prompt the musician to seek professional medical help to prevent the disorder's progression.

Biomechanical Comparison of Anatomic Restoration of the Ulnar Footprint vs Traditional Ulnar Tunnels in Ulnar Collateral Ligament Reconstruction

Background: Current techniques for ulnar collateral ligament (UCL) reconstruction do not reproduce the anatomic ulnar footprint of the UCL. The purpose of this study was to describe a novel UCL reconstruction technique that utilizes proximal-to-distal ulnar bone tunnels to better re-create the anatomy of the UCL and to compare the biomechanical profile at time zero among this technique, the native UCL, and the traditional docking technique. Hypothesis: The biomechanical profile of the anatomic technique is similar to the native UCL and traditional docking technique. Study Design: Controlled laboratory study. Methods: Ten matched cadaveric elbows were potted with the forearm in neutral rotation. The palmaris longus tendon graft was harvested, and bones were sectioned 14 cm proximal and distal to the elbow joint. Specimen testing included (1) native UCL testing performed at 90° of flexion with 0.5 N·m of valgus moment preload, (2) cyclic loading from 0.5 to 5 N·m of valgus moment for 1000 cycles at 1 Hz, and (3) load to failure at 0.2 mm/s. Elbows then underwent UCL reconstruction with 1 elbow of each pair receiving the classic docking technique using either anatomic (proximal to distal) or traditional (anterior to posterior) tunnel locations. Specimen testing was then repeated as described. Results: There were no differences in maximum load at failure between the anatomic and traditional tunnel location techniques (mean ± SD, 34.90 ± 10.65 vs 37.28 ± 14.26 N·m; P = .644) or when including the native UCL (45.83 ± 17.03 N·m; P = .099). Additionally, there were no differences in valgus angle after 1000 cycles across the anatomic technique (4.58°± 1.47°), traditional technique (4.08°± 1.28°), and native UCL (4.07°± 1.99°). The anatomic group and the native UCL had similar valgus angles at failure (24.13°± 5.86° vs 20.13°± 5.70°; P = .083), while the traditional group had a higher valgus angle at failure when compared with the native UCL (24.88°± 6.18° vs 19.44°± 5.86°; P = .015). Conclusion: In this cadaveric model, UCL reconstruction with the docking technique utilizing proximal-to-distal ulnar tunnels better restored the ulnar footprint while providing valgus stability comparable with reconstruction with the docking technique using traditional anterior-to-posterior ulnar tunnel locations. These results suggest that utilization of the anatomic tunnel location in UCL reconstruction has similar biomechanical properties to the traditional method at the time of initial fixation (ie, not accounting for healing after reconstruction in vivo) while keeping the ulnar tunnels farther from the ulnar nerve. Further studies are warranted to determine if an anatomically based UCL reconstruction results in differing outcomes than traditional reconstruction techniques. Clinical Relevance: Current UCL reconstruction techniques do not accurately re-create the ulnar UCL footprint. The UCL is a dynamic constraint to valgus loads at the elbow, and a more anatomic reconstruction may afford more natural joint kinematics. This more anatomic technique performs similarly to the traditional docking technique at time zero, and the results of this study may offer a starting point for future in vivo studies.

Variant Trifurcation of the Ulnar Nerve in Guyon’s Canal of the Human Wrist: Case report

During routine dissection of the right hand of a 52-year-old Asian descent male cadaver in the Department of Anatomy at Jazan University-Faculty of Medicine, we observed an anatomical variation of the ulnar nerve (UN). There was a trifurcation of the nerve in the ulnar tunnel proximal to the pisiform bone. An awareness of such variation may be of great clinical importance despite the presence of trifurcation of the ulnar nerve, which does not usually cause symptoms but becomes important in the evaluation of entrapment neuropathy and during surgical and orthopedic interventions

Reliability of deep branch of ulnar nerve identification in interosseous-to-ulnar motor nerve transfer: A cadaver study of 20 wrists

Reinnervation of the intrinsic hand muscles after proximal ulnar nerve repair is often unsatisfactory. Promising results have nevertheless been reported recently for supercharged end-to-side anterior interosseous to deep branch of the ulnar nerve (DBUN) transfer. The aim of this study was to determine whether the DBUN can be reliably identified without retrograde intraneural dissection from Guyon’s canal. Twenty cadaveric wrists were dissected. In a first stage, nerve transfer was performed through a limited 4 cm incision without releasing Guyon’s canal. In a second stage, correct identification of the DBUN was assessed by retrograde intraneural dissection from its point of exit from Guyon’s canal. The DBUN was correctly identified in 18 of the 20 wrists (90%). Although anatomical landmarks provide valuable clues, identifying the DBUN by neurolysis is technically challenging. All the elements required for nerve transfer can be exposed through a 4 cm incision, but the DBUN was nevertheless incorrectly identified in 10% of cases. Guyon canal release seems advisable to guarantee correct DBUN identification.

Arthroscopic one-tunnel transosseous reconstruction of chronic triangular fibrocartilage complex foveal tears: outcomes in 12 patients

We report the surgical method and outcomes of a simple arthroscopic-assisted technique of repairing triangular fibrocartilage complex (TFCC) foveal injuries in 12 patients with chronic distal radioulnar joint instability. An ulnar transosseous tunnel was created with its distal exit point located 3 to 4 mm radial to the fovea. A tendon graft was cut into two parts, and both were then passed through the bone tunnel to secure the radioulnar ligament remnants back to the fovea in a 'V' shape configuration. At the final follow-up of 13 to 26 months (average 21), all patients had a reduction of wrist pain, with the mean visual analogue scale dropped from 4.6 to 1.6 out of 10. The distal radioulnar joint was completely stable in nine patients and had improved stability in three patients. The mean Mayo modified wrist scores improved from 72 to 89, and the clinical outcomes were excellent in four patients, good in seven and fair in one. No major surgical complications occurred. This simple arthroscopic one-tunnel transosseous approach is effective for chronic foveal tears of the TFCC with intact radioulnar ligament remnants.Level of evidence: IV.

Possible points of compression of the ulnar nerve: Tricks and traps that await clinicians from an anatomical point of view.

The ulnar nerve can be subject to numerous types of compression. The most common are cubital tunnel and ulnar tunnel syndromes, but there are many others with more uncommon etiologies. The existence of additional communicating branches, median nerve involvement, various types of injuries, and unusual anatomical variations can be a challenge for both diagnosis and treatment. This review presents a comprehensive depiction of ulnar nerve entrapment syndromes with particular reference to their anatomical background, risk factors, and clinical evaluation. Even common disorders can result from atypical morphological changes. It is important to be familiar with them as it is a key ability in daily medical practice.

Compression Neuropathies of the Upper Extremity: A Review

Compressive neuropathies of the forearm are common and involve structures innervated by the median, ulnar, and radial nerves. A thorough patient history, occupational history, and physical examination can aid diagnosis. Electromyography, X-ray, and Magnetic Resonance Imaging may prove useful in select syndromes. Generally, first line therapy of all compressive neuropathies consists of activity modification, rest, splinting, and non-steroidal anti-inflammatory drugs. Many patients experience improvement with conservative measures. For those lacking adequate response, steroid injections may improve symptoms. Surgical release is the last line therapy and has varied outcomes depending on the compression. Carpal Tunnel syndrome (CTS) is the most common, followed by ulnar tunnel syndrome. Open and endoscopic CTS release appear to have similar outcomes. Endoscopic release appears to incur decreased cost baring a low rate of complications, although this is debated in the literature. Additional syndromes of median nerve compression include pronator syndrome (PS), anterior interosseous syndrome, and ligament of Struthers syndrome. Ulnar nerve compressive neuropathies include cubital tunnel syndrome and Guyon’s canal. Radial nerve compressive neuropathies include radial tunnel syndrome and Wartenberg’s syndrome. The goal of this review is to provide all clinicians with guidance on diagnosis and treatment of commonly encountered compressive neuropathies of the forearm.

Arthroscopic Triangular Fibrocartilage Complex Reconstruction Using a Palmaris Longus Tendon Graft.

Patients suffer from persistent ulnar wrist pain and distal radioulnar joint instability because of chronic triangular fibrocartilage complex (TFCC) foveal tear are treated with TFCC reconstruction. We performed an arthroscopic TFCC reconstruction using a palmaris longus tendon graft that provided a minimally invasive procedure. After confirming the TFCC foveal tear and stability between the TFCC remnant and radius, the bone tunnel was made in the ulna from the ulnar shaft to ulnar fovea. The position of the bone tunnel was checked by fluorography and arthroscopy. Curved bendable 18-gauge needles into which 3-0 nylon sutures were inserted in a loop shape were passed through the tunnel from the ulnar side, and both volar-side and dorsal-side TFCC remnants were penetrated. The nylon suture was extracted from the arthroscopic 4/5 portal, and the palmaris longus tendon graft was introduced into the joint. The graft was passed through the TFCC remnant and ulnar bone tunnel from the arthroscopic portal and fixed to the ulna using an interference screw. This procedure was indicated for TFCC foveal tears with intact radial-side TFCC remnants. If the radial-side tear and instability between the TFCC and radius coexist, this technique is contraindicated, and stabilization of both the radial and ulnar sides of the TFCC should be considered. This arthroscopic technique does not violate the distal radioulnar joint capsule, extensor carpi ulnaris tendon, or tendon sheath. In addition, it helps to stabilize the ulnar carpal complex.

In Situ Neurolysis of Ulnar Nerve for Patients With Failed Anterior Subcutaneous Transposition - A Case Series.

BACKGROUNDVarious surgical techniques have been attempted to treat patients with failed anterior subcutaneous transposition performed for cubital tunnel syndrome.OBJECTIVETo analyze intraoperative findings of failed anterior subcutaneous transposition and to report the outcome of in Situ neurolysis of ulnar nerve.METHODSPatients who, under diagnosis of failed anterior subcutaneous transposition of ulnar nerve, underwent in Situ neurolysis between 2001 and 2018 were included in this study. We excluded patients with follow-up of less than one year, records of traumatic ulnar nerve injury, and concomitant double crush syndrome such as cervical spondylosis causing radicular pain, ulnar tunnel syndrome, or thoracic outlet syndrome. Surgical outcomes were evaluated using visual analog scale (VAS) pain score and Disabilities of the Arm, Shoulder, and Hand (DASH) score, which were assessed before and after surgery. A total of 28 elbows in 27 patients whose average age was 58.5 (range, 31-76) yr were enrolled, and the duration of follow-up was 5.8 (range, 1.0-14.9) yr.RESULTSThe most common pathologic finding identified during operation was severe adhesion of the transposed nerve in all elbows, followed by incomplete decompression of deep flexor-pronator aponeurosis in 26 elbows (93%). The average VAS pain score improved from 4.9 (range, 2-7) to 1.3 (range, 0-5), and the average DASH score from 31.7 (range, 18.1-66.7) to 14.1 (range, 5.0-46.6). Of the 28 elbows, 27 (96.4%) showed improvement of preoperative symptoms.CONCLUSIONIn Situ neurolysis of ulnar nerve for patients with failed anterior subcutaneous transposition resulted in satisfactory outcome.

Presentation of the hypothenar hammer syndrome as a low incidence aneurysmal disorder of the ulnar artery.

Introduction and importanceThe hypothenar hammer syndrome (HHS) is either rare or underdiagnosed condition that arises from vascular insufficiency of the ulnar artery in the hand. The most common accused mechanism is repetitive blunt trauma to hypothenar region while activating the latter as a hammer to do the job.Case presentationA 48 year old woman worked as a master of university claimed from pain and numbness in her left hand concurrent with a pulsatile mass. The second case was a 48 year old man who was a mechanic engineer in automotive industry that claimed of a pain and pulsatile mass in his non-dominant left hand.Clinical discussionUlnar artery enters the hand from Guyon's canal where fixes to adjacent structure and is susceptible for injury. Aneurysmal formation is an outcome of arterial trauma which could result in distal necrosis if remains untreated.ConclusionThis study has revealed that even whether a single blunt trauma or writing with pen could lead to aneurysmal formation. It has also showed primary aneurysmal resection with no further surgical procedure is both safe and reliable if digital ischemia is not concurrently present.

Influential factors of surgical decompression for ulnar nerve neuropathy in Guyon's canal.

Guyon's canal syndrome is nerve compressive pathology which can lead to sensory and/or motor function deficits. This problem is usually difficult to distinguish from cubital tunnel syndrome and relatively less common than cubital tunnel syndrome. This study evaluated the functional results and patient-reported outcomes following decompression of the ulnar nerve in Guyon's canal. Patients who were diagnosed with Guyon's canal syndrome confirmed by electrodiagnostic studies and underwent nerve decompression surgery were included in this study. The functional improvement by examining the Froment's sign, Wartenberg's sign, static two-point discrimination, and Semmes Weinstein monofilament examination as physical examination scores was evaluated. The visual analogue scale of satisfaction and the disabilities of the arm, shoulder, and hand questionnaire were used for the postoperative patient-reported outcome evaluation. From 2003 to 2019, 38 cases had been enrolled with a mean age of 53 years, ranging from 19 to 85 years. There were seven patients with comorbidity of diabetes mellitus and 28 patients who received additional neurolysis combined with the Guyon's release procedure. There were 19 patients with a good response to surgery and 10 patients with a poor surgical outcome due to persistent paresthesia or weakness. After statistical analysis, it was revealed that several influential factors could have been related to a compromised functional outcome, including a symptom duration of more than 3 months, combination with additional neurolysis of ipsilateral extremity, and/or comorbidity with diabetes mellitus. It was concluded that promising functional outcomes after surgical release of ulnar neuropathy in Guyon's canal could be achieved if the patients did not need additional neurolysis or the symptom duration was within 3 months.

Surgical Anatomy of the Medial Antebrachial Cutaneous Nerve: Clinical Application in Ulnar Nerve Decompression Surgery in the Elbow

Abstract Introduction Lesion to the posterior branch of the medial antebrachial cutaneous nerve (MACN) is one of the causes of revision of the ulnar nerve decompression surgery in the elbow.To avoid the morbidity associated with this injury, cadaver dissections were performed to identify this branch in its course through the ulnar tunnel. Methods We included 20 upper extremities of fresh cadaveric specimens. The posterior branch of the MACN was identified proximal to medial epicondyle and followed past the ulnar tunnel. The number of ramifications and their coordinates were recorded in a Cartesian plane, with the medial epicondyle as the central point. Results The posterior branch passed proximal and posterior to the medial epicondyle in all specimens, except one. The average of the adjusted x value is of 30 mm, and of the adjusted y value is -18 mm. Additionally, we determined that the posterior branch passes at an average angle of 30° with respect to the x axis. Conclusion The anatomical descriptions of this branch focused on surgical release of the ulnar nerve in the elbow are limited, and measures are only described in the horizontal plane (from proximal to distal). Schematizing the anatomy of this branch in its course throughout the ulnar tunnel will facilitate its identification during the procedures. However, variability and asymmetry in the branching pattern should be considered.

A novel local adipofascial flap for the management of recalcitrant ulnar tunnel syndrome

Ulnar tunnel syndrome is the second most common upper-limb peripheral nerve compression syndrome. Recurrence or persistence of symptoms after primary surgery is found in 9.9%–21% of cases. The main cause of failure is peri- and endo-neural fibrosis, and management is difficult and controversial. Revision of nerve neurolysis combined with freestyle adipofascial flap provides nerve decompression and coverage with vascularized tissue, which prevents scar tissue formation around the nerve and restores glide. We performed a preliminary vessel-injected cadaver study. The perforating vessels from the posterior recurrent ulnar artery vascularize the medial adipose and fascial tissues of the elbow, allowing elevation of an adipofascial flap which is able to reach the ulnar nerve. Eight patients with neuropathic ulnar nerve pain in recalcitrant ulnar tunnel syndrome due to peri- and/or endo-neural fibrosis were treated by neurolysis, and the nerve was covered with an ulnar adipofascial flap. All patients were evaluated by percussion test, visual analog scale for pain, electromyography, electroneurography and ultrasound, and were classified according to the McGowan classification as modified by Goldberg. The study was approved by the review board. All patients had good 4-year outcome, with complete return to daily activity, work and sports 4 months after surgery. The results of this novel surgical technique were encouraging, without complications or donor site morbidity. Adipofascial flap combined with neurolysis could be a valid solution in the treatment of recalcitrant ulnar tunnel syndrome.

Enhancing diagnostic accuracy using a side-to-side cross-sectional area ratio for the diagnosis of unilateral ulnar mononeuropathy at the elbow.

Neuromuscular ultrasonography (NMUS) is a valuable adjunct to electrodiagnostic testing for the diagnosis of entrapment neuropathy. The aim of this study was to determine whether diagnostic accuracy of NMUS could be enhanced in patients with unilateral ulnar mononeuropathy at the elbow (UNE) by utilizing side-to-side ulnar nerve cross-sectional area (CSA) ratios. Retrospective case-control analysis of unilateral UNE cases identified cutoff values for elbow segment ulnar nerve maximum CSA (MCSA) of the symptomatic/asymptomatic limb (M ratio), as well as side-to-side ratios comparing MCSA with ipsilateral CSA at the Guyon canal (E/G), middle forearm (E/F), and middle humerus (E/H). Diagnostic accuracy values were calculated. The optimal M-ratio cut-off was 1.22 (sensitivity, 92.9%; specificity, 97.8%; accuracy, 95.4%). Optimal cutoffs for inter-E/G, -E/F, and -E/H ratios were 1.07 (sensitivity, 98%; specificity, 78%; accuracy, 87.7%), 1.11 (sensitivity, 95%; specificity, 80%; accuracy, 87.2%), and 1.18 (sensitivity, 95%; specificity, 93%; accuracy, 94%), respectively. The M ratio and inter-E/H ratio exhibited high diagnostic accuracy for unilateral UNE. Prospective studies are needed to compare the accuracy of the new measures with a single MCSA measurement.