Ulnar Nerve Instability Research Articles

Ultrasound-guided percutaneous release of the ulnar nerve at the elbow.

Ultrasound-guided percutaneous release of the ulnar nerve at the elbow.

Relationship Between Ulnar Nerve Instability and the Degree of Ulnar Collateral Ligament Laxity in High School Baseball Pitchers

Relationship Between Ulnar Nerve Instability and the Degree of Ulnar Collateral Ligament Laxity in High School Baseball Pitchers

Cubital tunnel syndrome in the presence of ulnar nerve instability: a review of current treatment options

Cubital tunnel syndrome (CuTS) is a common ulnar nerve entrapment of the elbow that can be caused by a variety of stresses and inflammatory conditions. Ulnar nerve instability (UNI) is a loosely defined term to describe ulnar nerve hypermobility at the elbow that has a widely varied symptom profile. CuTS and UNI can occur individually or comorbidly, and the causality of their relationship is unclear. The purpose of this review is to examine literature on treatment options for CuTS in the presence of UNI. Hand surgeons have accepted initial surgical treatment to be anterior transposition, but recent literature suggests that a combination of endoscopic decompression and traditional, or partial medial epicondylectomy may be efficacious for some patients. Until large scale studies are performed comparing the approaches, surgeons must take into account how they were trained, the patient’s presentation, and the patient’s goals when determining what approach to utilize.

WALANT office based endoscopic cubital tunnel release

Background: Cubital tunnel syndrome is a common condition caused by compression of the ulnar nerve around the medial elbow. Surgical treatment usually involves open in situ ulnar nerve decompression unless ulnar nerve instability is noted. Endoscopic techniques for cubital tunnel release have been developed and implemented with excellent patient and surgeon satisfaction. Endoscopic cubital tunnel release can be performed in an office based procedure room under wide awake local anesthesia no tourniquet principles. We present our setup and technique for performing an endoscopic cubital tunnel release procedure in an office based setting under local anesthesia. Methods: Local anesthesia is injected along the course of the ulnar nerve on the medial arm and forearm extending 10 cm proximal and distal to the medial epicondyle. After allowing approximately 30 min for appropriate vasoconstriction, the patient is placed in a supine position with the arm abducted and externally rotated position. The endoscopic cubital tunnel release is then performed. Discussion: Our described technique eliminates the need for placement of a prophylactic tourniquet and thereby the need for the procedure to be performed within an OR setting. It also utilizes a single-stage anesthetic administration, which facilitates ease of completion and performance in an office based setting. There is a significant cost savings when endoscopic cubital tunnel release is performed in an office-based procedure room compared to in the operating room. Conclusions: Office-based endoscopic cubital tunnel release can be safely performed utilizing WALANT techniques, leading to high patient satisfaction and decreased overall cost of care. Level of Evidence: Therapeutic IV

A novel classification of intraoperative ulnar nerve instability to aid transposition surgery

A novel classification of intraoperative ulnar nerve instability to aid transposition surgery

Ultrasonographic evaluation of ulnar nerve morphology in patients with ulnar nerve instability.

Ulnar nerve instability (UNI) in the retroepicondylar groove is described as nerve subluxation or dislocation. In this study, considering that instability may cause chronic ulnar nerve damage by increasing the friction risk, we aimed to examine the effects of UNI on nerve morphology ultrasonographically. Asymptomatic patients with clinical suspicion of UNI were referred for further clinical and ultrasonographic examination. Based on ulnar nerve mobility on ultrasound, the patients were first divided into two groups: stable and unstable. The unstable group was further divided into two subgroups: subluxation and dislocation. The cross-sectional area (CSA) of the nerve was measured in three regions relative to the medial epicondyle (ME). In the ultrasonographic evaluation, UNI was identified in 59.1% (52) of the 88 elbows. UNI was bilateral in 50% (22) of the 44 patients. Mean CSA was not significantly different between groups. A statistically significant difference in ulnar nerve mobility was found between the group with CSA of <10 versus ≥10 mm2 (p = .027). Nerve instability was found in 85.7% of elbows with an ulnar nerve CSA value of ≥10 mm2 at the ME level. The probability of developing neuropathy in patients with UNI may be higher than in those with normal nerve mobility. Further prospective studies are required to elucidate whether asymptomatic individuals with UNI and increased CSA may be at risk for developing symptomatic ulnar neuropathy at the elbow.

Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers

Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers

In Situ Stabilization of the Ulnar Nerve as an Alternative to Transposition in Traumatic Ulnar Nerve Instability: A Case Report.

We present the case of a 25-year-old male sports climber treated with in situ ulnar nerve stabilization for ulnar nerve instability (UNI) by using 2 fascial flaps. Symptomatic UNI has traditionally been managed with subcutaneous or submuscular ulnar nerve transposition. Transposition is relatively invasive and when performed subcutaneously, embeds the ulnar nerve in an exposed location, which may render it prone to mechanical injury in physically active patients. In situ stabilization may be a less invasive alternative to transposition in select patients involved in sports such as rock climbing.

Assessment of ulnar nerve stability at the elbow by ultrasonography in children

Assessment of ulnar nerve stability at the elbow by ultrasonography in children

Ulnar Nerve Transposition (Cadaver)

Ulnar nerve transposition is a surgical procedure performed to treat ulnar nerve compression of the elbow, also known as cubital tunnel syndrome. This procedure is utilized after both non-operative management and in situ decompression fails, or if these procedures are deemed inappropriate based on patient pathology or ulnar nerve instability. Transposition of the ulnar nerve involves not only decompression of the nerve but also its anterior repositioning to reduce compression and irritation while maintaining nerve integrity. This video outlines the operative technique used by Dr. Asif Ilyas for performing an ulnar nerve transposition using either a subcutaneous or a submuscular technique.

Temporary splint application in extension to prevent ulnar nerve instability after in situ release

Temporary splint application in extension to prevent ulnar nerve instability after in situ release

Role of dynamic ultrasound in assessment of the snapping elbow and distal biceps tendon injury.

Ultrasound is useful in assessing patients with snapping syndromes around the elbow joint. The dynamic nature of the examination allows for direct visualisation of the underlying causative factor.Topic description: We discuss the role of dynamic ultrasound in assessing various snapping syndromes around the elbow, such as ulnar nerve instability, snapping triceps and less commonly, snapping brachialis. Ultrasound is also useful in evaluating the distal biceps tendon, particularly in differentiating partial from complete tendon injury. Ulnar nerve instability and snapping triceps can be assessed via a medial approach with the transducer placed transversely between the medial epicondyle and the olecranon. In ulnar nerve instability, the nerve can be seen crossing over the medial epicondyle on elbow flexion. In snapping triceps syndrome, both the ulnar nerve and the distal triceps can be seen dislocating over the medial epicondyle. Dynamic assessment of the distal biceps tendon using a lateral approach minimises anisotropy artefact often seen on the anterior approach. Passive pronation and supination of the forearm will reveal little or no movement in a completely torn tendon whereas moving tendon fibres will be appreciated in partial tears. In a snapping brachialis, the medial portion of brachialis will be seen abnormally translocating anterolateral to the medial border of the trochlea during elbow flexion and snapping back into its normal position on elbow extension. Dynamic ultrasound of the elbow is valuable in diagnosing patients with snapping sensations around the joint and in evaluating the integrity of the distal biceps tendon.

The ultrasonographic assessment of the morphologic changes in the ulnar nerve at the cubital tunnel in Japanese volunteers: relationship between dynamic ulnar nerve instability and clinical symptoms.

The ultrasonographic assessment of the morphologic changes in the ulnar nerve at the cubital tunnel in Japanese volunteers: relationship between dynamic ulnar nerve instability and clinical symptoms.

Ulnar Neuropathy at the Elbow: From Ultrasound Scanning to Treatment.

Ulnar neuropathy at the elbow (UNE) is commonly encountered in clinical practice. It results from either static or dynamic compression of the ulnar nerve. While the retroepicondylar groove and its surrounding structures are quite superficial, the use of ultrasound (US) imaging is associated with the following advantages: (1) an excellent spatial resolution allows a detailed morphological assessment of the ulnar nerve and adjacent structures, (2) dynamic imaging represents the gold standard for assessing the ulnar nerve stability in the retroepicondylar groove during flexion/extension, and (3) US guidance bears the capability of increasing the accuracy and safety of injections. This review aims to illustrate the ulnar nerve's detailed anatomy at the elbow using cadaveric images to understand better both static and dynamic imaging of the ulnar nerve around the elbow. Pathologies covering ulnar nerve instability, idiopathic cubital tunnel syndrome, space-occupying lesions (e.g., ganglion, heterotopic ossification, aberrant veins, and anconeus epitrochlearis muscle) are presented. Additionally, the authors also exemplify the scientific evidence from the literature supporting the proposition that US guidance is beneficial in injection therapy of UNE. The non-surgical management description covers activity modifications, splinting, neuromobilization/gliding exercise, and physical agents. In the operative treatment description, an emphasis is put on two commonly used approaches—in situ decompression and anterior transpositions.

Fascial Epicondylar Augmentation in Cases of Cubital Tunnel Syndrome With Ulnar Nerve Instability.

Cubital tunnel syndrome (CubTS) is one of the most common compression-traction neuropathy in the upper extremity. The gold standard is simple in situ decompression with revision of potential compression sites through skin incision as small as rationally possible. Properly conducted conservative treatment is more effective in CubTS as opposed to carpal tunnel syndrome. At the same time, optimal management of CubTS remains controversial. Nevertheless, there is a subclass of patients with symptoms of CubTS that have ulnar nerve instability (UNI) with subluxation of the nerve over the medial epicondyle where conservative treatment would not be successful. UNI can be diagnosed by ultrasound preoperatively, but there are situations where the ulnar nerve becomes unstable with elbow flexion already on the operating table. Currently the most popular surgical reconstruction for clinically relevant UNI is anterior transposition of the nerve. With the proposed technique the nerve stays in orthotopic position, and the segmental vascularity is preserved, innervation to the flexor carpi ulnaris muscle is not jeopardized and ulnar nerve glide-floss exercises are possible as opposed to the standard subcutaneous transposition technique. No subfascial transposition, slings or blocking flaps are used for nerve stabilization which we consider contradiction to the surgery of nerve release.

The impact of pre-existing ulnar nerve instability on the surgical treatment of cubital tunnel syndrome: a systematic review

The impact of pre-existing ulnar nerve instability on the surgical treatment of cubital tunnel syndrome: a systematic review

The Triceps Traction Test: A Decision Tool for the Choice of Stabilizing Flap After In Situ Decompression of the Ulnar Nerve.

Recent evidence demonstrates that in situ decompression has comparable outcomes to other surgical techniques for cubital tunnel syndrome. However, this technique does not address the instability of the ulnar nerve, a common indication to transpose the ulnar nerve. Transposition of the ulnar nerve can potentially devascularize the ulnar nerve, stabilizing flaps block subluxation of the ulnar nerve and thereby negate the need for transposition. Flaps originating from the triceps and the flexor-pronator fascia could be used to stabilize the ulnar nerve. Herein, we present a novel intraoperative test, the "triceps traction test" and our algorithm for choosing a stabilizing flap when ulnar nerve instability is encountered after in situ decompression.

Double Fascial Flap Stabilization for Ulnar Nerve Instability After In Situ Decompression

Double Fascial Flap Stabilization for Ulnar Nerve Instability After In Situ Decompression

In idiopathic cubital tunnel syndrome, ulnar nerve excursion and instability can be reduced by repairing Osborne's ligament after simple decompression.

Osborne's modified decompression involves repairing Osborne's ligament beneath the ulnar nerve after simple decompression for idiopathic cubital tunnel syndrome. In this retrospective interrupted time series, 31 patients underwent modified simple decompression and 20 patients underwent conventional simple decompression. In the modified simple decompression group, the ulnar nerve length was measured at operation in full elbow flexion and extension before and after repair of Osborne's ligament. Ulnar nerve instability during elbow motion was measured using ultrasonography before operation and at 12 months after operation. In patients treated by modified simple decompression, the ulnar nerve length in full elbow flexion reduced significantly after repair of Osborne's ligament. At 12 months after surgery, the grade of ulnar nerve instability was lower in the modified simple decompression group than in the conventional simple decompression group. The clinical outcomes did not differ significantly between the groups at 24 months after operation. Level of evidence: III.

Ulnar nerve instability in the cubital tunnel of asymptomatic volunteers.

Ulnar nerve instability (UNI) in the cubital tunnel is defined as ulnar nerve subluxation or dislocation. It is a common disorder that may be noted in patients with neuropathy or in the asymptomatic. Our prospective, single-site study utilized high-resolution ultrasonography (US) to evaluate the ulnar nerve for cross-sectional area (CSA) and measures of shear-wave elastography (SWE). Mechanical algometry was obtained from the ulnar nerve in the cubital tunnel to assess pressure pain threshold (PPT). Forty-two asymptomatic subjects (n = 84 elbows) (25 males, 17 females) aged 22-40 were evaluated. Two chiropractic radiologists, both with 4years of ultrasound experience performed the evaluation. Ulnar nerves in the cubital tunnel were sampled bilaterally in three different elbow positions utilizing US, SWE, and algometry. Descriptive statistics, two-way ANOVA, and rater reliability were utilized for data analysis with p ≤ 0.05. Fifty-six percent of our subjects demonstrated UNI. There was a significant increase in CSA in subjects with UNI (subluxation: 0.066mm2 ± 0.024, p = 0.027; dislocation: 0.067mm2 ± 0.024, p = 0.003) compared to controls (0.057mm2 ± 0.017) in all three elbow positions. There were no significant group differences in SWE or algometry. Inter- and intra-observer agreements for CSA of the ulnar nerves within the cubital tunnel were assessed using intraclass correlation coefficient (ICC) and demonstrated moderate (ICC 0.54) and excellent (ICC 0.94) reliability. Most of the asymptomatic volunteers demonstrated UNI. There was a significant increase in CSA associated with UNI implicating it as a risk factor for ulnar neuropathy in the cubital tunnel. There were no significant changes in ulnar nerve SWE and PPT. Intra-rater agreement was excellent for the CSA assessment of the ulnar nerve in the cubital tunnel. High-resolution US could be utilized to assess UNI and monitor for progression to ulnar neuropathy.