Retrocondylar Groove Research Articles

Ulnar Nerve Hydrodissection at the Elbow With Ultrasound Guidance

Background: Ulnar neuropathy at the elbow (UNE) is common, and treatment ranges from bracing and nonsteroidal anti-inflammatory drugs (NSAIDs) to surgical decompression. Prior to surgical intervention, some patients may opt to receive perineural injections to the ulnar nerve. The goal of this injection is to reduce pain, improve symptoms, and decrease nerve cross-sectional area through mechanical decompression. While the use of hydrodissection as a treatment for carpal tunnel syndrome has been well studied, there are few studies evaluating its utility in UNE. Indications: Ultrasound-guided perineural injections can be used to alleviate symptoms of UNE caused by compression. The use of a gel stand-off technique is helpful in maintaining adequate visualization of the needle with a steeper needle angle. Technique Description: The procedure was carried out with patient supine, shoulder abducted to 90°, and the forearm supinated. A 15-6 MHz linear array ultrasound transducer was used to localize the right ulnar nerve proximal to the retrocondylar groove at an area of focal hypoechogenicity and increased nerve cross-sectional area. A 3 mL mixture of 2 mL of 1% lidocaine and 1 mL of 10 mg/mL dexamethasone was injected using a sonographically guided in-plane anterior-to-posterior technique. Results: Our patient was seen 3 weeks after her right-sided ulnar nerve hydrodissection and had experienced temporary reduction in symptoms. Discussion/Conclusion: UNE is a common cause of focal neuropathy. Most patients will experience adequate relief of symptoms with conservative treatment modalities. If patients do not experience adequate symptom relief, ultrasound-guided ulnar nerve injection is a minimally invasive option that can provide symptom relief. However, if patients continue to experience significant symptom burden, it is reasonable to discuss surgical options for ulnar nerve decompression. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Clinical and neurophysiological recovery of ulnar nerve conduction block at the elbow.

An important mechanism of peripheral nerve motor and sensory dysfunction is conduction block (CB). However, recovery from mechanically induced CB has been rarely studied in humans. The aim of this study was to describe clinical, electrodiagnostic (EDx), and ultrasonographic (US) characteristics of CB recovery in ulnar neuropathy at the elbow (UNE). We recruited a group of consecutive patients presenting to our EDx laboratory with UNE and >50% motor CB. Patients' histories were obtained and neurologic, EDx, and US examinations were repeated every 1-3 mo for at least 12 mo. We studied 10 patients (5 men), with a mean age of 63 y (range, 51-81 y). In all affected arms CB was localized to the retrocondylar groove. Following conservative management, myometrically measured index finger abduction improved from a median of 49% to 100% relative to the contralateral index finger, and ulnar nerve CB decreased from a median of 74% to 6%. Most of the improvement took place within 8 mo of symptom onset, and 6 mo after receiving treatment instructions. Mean motor nerve conduction velocity improved from 15 to 27 m/s in the most affected 2-cm ulnar nerve segment. The resolution of CB after typical chronic compression may take longer than after acute compression. This should be considered by clinicians when estimating prognosis for discussions with patients.

Role of diffusion tensor imaging in the evaluation of ulnar nerve involvement in leprosy.

Early detection of peripheral neuropathy is extremely important as leprosy is one of the treatable causes of peripheral neuropathy. The study was undertaken to assess the role of diffusion tensor imaging (DTI) in ulnar neuropathy in leprosy patients. This was a case-control study including 38 patients (72 nerves) and 5 controls (10 nerves) done between January 2017 and June 2019. Skin biopsy proven cases of leprosy, having symptoms of ulnar neuropathy (proven on nerve conduction study) were included. MRI was performed on a 3 T MR system. Mean cross-sectional area, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of ulnar nerve at cubital tunnel were calculated. Additional ancillary findings and appearance of base sequences were evaluated. Ulnar nerve showed thickening with altered T2W signal in all the affected nerves, having an average cross-sectional area of 0.26 cm2. Low FA with mean of 0.397 ± 0.19 and high ADC with mean of 1.28 ± 0.427 x 10 -3 mm2/s of ulnar nerve in retrocondylar groove was obtained. In the control group, mean cross-sectional area was 0.71cm2 with mean FA and ADC of 0.53 ± 0.088 and 1.03 ± 0.24 x 10 -3 mm2/s respectively. Statistically no significant difference was seen in diseased and control group. Cut-off to detect neuropathy for FA and ADC is 0.4835 and 1.1020 × 10 -3 mm2/s respectively. DTI though is challenging in peripheral nerves, however, is proving to be a powerful complementary tool for assessment of peripheral neuropathy. Our study validates its utility in infective neuropathies. 1. DTI is a potential complementary tool for detection of peripheral neuropathies and can be incorporated in standard MR neurography protocol.2. In leprosy-related ulnar neuropathy, altered signal intensity with thickening or abscess of the nerve is appreciated along with locoregional nodes and secondary denervation changes along with reduction of FA and rise in ADC value.3. Best cut-offs obtained in our study for FA and ADC are 0.4835 and 1.1020 × 10 -3 mm2/s respectively.

Patterns and parameters describing nerve thickening in compression and entrapment ulnar neuropathies at the elbow

ObjectiveTo compare pattern and parameters describing nerve thickening in ulnar neuropathy at the elbow (UNE) due to external compression in the retrocondylar groove (RTC), and entrapment under the humeroulnar aponeurosis (HUA). MethodsIn a group of our previously reported UNE patients we ultrasonographically (US) measured ulnar nerve cross-sectional areas (CSA) on 6–8 standard locations in the elbow segment. We compared CSA patterns in both groups, and determined diagnostic utility of selected CSA based parameters. ResultsWe studied 79 patients (81 arms) with UNE due to external compression, and 53 patients (55 arms) due to entrapment. Maximal ulnar nerve CSA (>16 mm2), maximal CSA change (>7 mm2/1–2 cm) and maximal/minimal CSA ratio (>2.6) were significantly larger in UNE due to entrapment. They also differentiated these arms from arms with compression with sensitivities of 78%, 87% and 80%, and specificities of 90%, 94%, and 85%, respectively. ConclusionMaximal difference in CSA between points separated by 1–2 cm (>7 mm2/1–2 cm) very efficiently differentiated between UNE due to external compression and entrapment. SignificanceThe proposed parameter will hopefully complement precise localization in determining underlying mechanism of UNE. This may help physicians to determine the most appropriate treatment for UNE and possibly other focal neuropathies of unknown cause; i.e., conservative treatment for external compression and surgery for entrapment.

Classification and Treatment of Ulnar Nerve Subluxation Following Endoscopic Cubital Tunnel Release

PurposeEndoscopic cubital tunnel release (ECuTR) is an effective procedure to alleviate cubital tunnel syndrome. To improve patient outcomes and lessen concerns regarding ulnar nerve subluxation (UNS) after ECuTR, the current study proposes an intraoperative UNS classification system and subsequent treatment protocol. We present a preliminary report of patients treated under these guidelines.MethodsWe retrospectively reviewed 87 patients (100 ECuTRs). Nerve mobility was classified during surgery, in which grade 1 = no movement or partial subluxation; deep retrocondylar groove and/or no generalized hypermobility (no further intervention); grade 2 = partial subluxation; shallow retrocondylar groove and/or inherent generalized hypermobility (required medial epicondylectomy); and grade 3 = complete anterior dislocation (required medial epicondylectomy or anterior transposition). Clinical outcomes at final follow-up (mean ± SD, 34 ± 20.3 weeks; range, 5–89 weeks) were collected and included Disabilities of the Arm, Shoulder, and Hand questionnaires, visual analog scale pain score, grip and pinch strength, 2-point discrimination, and range of motion.ResultsWe report 37 patients (42 cases), grade 1 (n = 30), grade 2 (n = 1), and grade 3 (n = 11). Gross grip strength, lateral, 3-jaw chuck, and precision pinch strength recovered 87%, 90%, 105%, and 87%, respectively. Wrist and elbow range of motion returned to normal limits, 2-point discrimination improved to normal scores at final follow-up, Disabilities of the Arm, Shoulder, and Hand scores were reduced from 59.8 before to 29.9 after surgery, and visual analog scale pain score improved from 7.2 before to 2.5 after surgery (P < .001).ConclusionsTo our knowledge, this is the first study to classify UNS after ECuTR and describe a guideline for ensuing treatment. Our preliminary report of patients shows satisfactory outcomes, which suggests that our intraoperative UNS classification system has promise in preventing adverse complications of ulnar nerve hypermobility after ECuTR.Type of study/level of evidenceTherapeutic IV.

O125 Long term outcomes of patients with ulnar neuropathy at the elbow according to pathophysiology of the nerve lesion

Objective We think that idiopathic ulnar neuropathy at the elbow (UNE) mainly consists of two conditions: entrapment under the humero-ulnar aponeurosis (HUA) and extrinsic compression in the retrocondylar (RTC) groove. We treated our UNE patients with entrapment under the HUA with surgical release, and those with extrinsic compression in the RTC groove by avoidance of inappropriate arm positioning. We studied their long term outcomes. Methods We invited our cohort of UNE patients to follow-up examination that consisted of focused history, neurologic, electrodiagnostic (EDx) and ultrasonographic (US) examinations performed by four blinded investigators. Results At mean follow-up period of 881 days complete follow-up evaluation was performed in 117 (67%) of our patients. In patients with UNE under the HUA axonal (88%) and in RTC groove demyelinating lesions were mainly found (conduction block in 33% and conduction slowing in 39%). On testing ADM muscle in axonal group compound muscle action potential (CMAP) amplitude increased from 2.3 to 3.9 mV (normal > 6.5 mV), and strength from 5 to 8 N. Conduction block disappeared completely with muscle strength improvement from 7 to 13 N. No significant changes were found in patients with conduction slowing. Conclusion Our study demonstrated strong correlation between UNE mechanism, pathophysiology and outcome. Extrinsic compression in RTC groove mainly causes demyelinated nerve lesion with complete recovery after conservative treatment. By contrast, entrapment under the HUA mainly causes axonal nerve lesion with partial improvement after surgical treatment.

Cubital Tunnel Release

Cubital tunnel syndrome is a condition that affects the ulnar nerve as it crosses the medial elbow through the retrocondylar groove. It is the second most common compressive neuropathy, causing tingling and numbness in the ring and small fingers. In advanced cases of symptomatic cubital tunnel syndrome, weakness, altered dexterity, and atrophy of the intrinsic muscles of the hand may develop. Cubital tunnel syndrome can be treated with either a cubital tunnel release or an ulnar transposition. In this case, the former is demonstrated on a cadaveric arm.

The use of intraoperative electrophysiological monitoring in patients with decompression of the ulnar nerve near the elbow joint

At the elbow, the ulnar nerve may be compressed either in the retrocondylar groove, in the cubital tunnel, or compressed by Osborne's band. Optimal surgical therapy should be directed at the specific site of involvement. It is more difficult to identify the level of ulnar nerve compression. Anatomical variations may make it difficult to identify the causes of ulnar neuropathy at the elbow. The data obtained by inspection, probing, or electroneurography do not allow one to reliably identify the compression level. Intraoperative electroneuromyography performed in conjunction with 14 ulnar nerve explorations helped localize the precise site of compression in 12 cases. Intraoperative studies helped identify compression by Osborne band in 8 patients. We conclude that intraoperative electroneuromyography identifies compression levels of ulnar neuropathy more accurately than the conventional examination methods do.

Cubital Tunnel Syndrome – A Review and Management Guidelines

Cubital tunnel syndrome (CuTS) is the second most common peripheral nerve compression syndrome. In German-speaking countries, cubital tunnel syndrome is often referred to as sulcus ulnaris syndrome (retrocondylar groove syndrome). This term is anatomically incorrect, since the site of compression comprises not only the retrocondylar groove but the cubital tunnel, which consists of 3 parts: the retrocondylar groove, partially covered by the cubital tunnel retinaculum (lig. arcuatum or Osborne ligament), the humeroulnar arcade, and the deep flexor/pronator aponeurosis. According to Sunderland , cubital tunnel syndrome can be differentiated into a primary form (including anterior subluxation of the ulnar nerve and compression secondary to the presence of an anconeus epitrochlearis muscle) and a secondary form caused by deformation or other processes of the elbow joint. The clinical diagnosis is usually confirmed by nerve conduction studies. Recently, the use of ultrasound and MRI have become useful diagnostic tools by showing morphological changes in the nerve within the cubital tunnel. A differential diagnosis is essential in atypical cases, and should include such conditions as C8 radiculopathy, Pancoast tumor, and pressure palsy. Conservative treatment (avoiding exposure to external noxes and applying of night splints) may be considered in the early stages of cubital tunnel syndrome. When nonoperative treatment fails, or in patients who present with more advanced clinical findings, such as motor weakness, muscle atrophy, or fixed sensory changes, surgical treatment should be recommended. According to actual randomized controlled studies, the treatment of choice in primary cubital tunnel syndrome is simple in situ decompression, which has to be extended at least 5-6 cm distal to the medial epicondyle and can be performed by an open or endoscopic technique, both under local anesthesia. Simple decompression is also the therapy of choice in uncomplicated ulnar luxation and in most post-traumatic cases and other secondary forms. When the luxation is painful, or when the ulnar nerve actually "snaps" back and forth over the medial epicondyle of the humerus, subcutaneous anterior transposition may be performed. In cases of severe bone or tissue changes of the elbow (especially with cubitus valgus), the anterior transposition of the ulnar nerve may again be indicated. In cases of scarring, submuscular transposition may be preferred as it provides a healthy vascular bed for the nerve as well as soft tissue protection. Risks resulting from transposition include compromise in blood flow to the nerve as well as kinking of the nerve caused by insufficient proximal or distal mobilization. In these cases, revision surgery is necessary. Epicondylectomy is not common, at least in Germany. Recurrence of compression on the ulnar nerve at the elbow may occur. This review is based on the German Guideline "Diagnose und Therapie des Kubitaltunnelsyndroms" ( www.leitlinien.net ).

Die endoskopische Dekompression des Nervus ulnaris bei Kubitaltunnelsyndrom

Long endoscopic in situ decompression of the ulnar nerve in cubital tunnel syndrome (sulcus ulnaris syndrome) with direct visualization and minimal incision. Every cubital tunnel syndrome including a posttraumatic or arthrotic etiology, cubitus valgus, nerve dislocation, or other causes. Revision surgery after primary endoscopic decompression. Relative: irritation of the ulnar nerve by recurrent luxation. Relative: previous open primary surgery. Minimal longitudinal incision in the retrocondylar groove. The Osborne ligament is opened and the ulnar nerve identified. Dissection of a subcutaneous tunnel in the direction of the nerve. Decompression of the ulnar nerve by opening the muscle fascia proximally and distally while preserving all sensory nerves. Afterwards, the submuscular membrane with its fibrous bands between flexor carpi ulnaris and the nerve is opened while preserving all motor branches of the ulnar nerve. Bulky, slightly compressive dressing of the entire upper extremity to prevent excessive motion in 20 degrees elbow flexion for 3 days. Then, free motion is allowed during the day. At night, the arm should be kept in near extension for 14 days. Muscular atrophy prior to surgery should imply focused physiotherapy for ulnaris-innervated muscles 8 weeks postoperatively. 52 patients were operated using this method. 53% felt an immediate improvement right after surgery. 47 patients (90%) were available for reexamination after 8 months. Two-point discrimination, grip and pinch strength, and nerve conduction velocity had improved significantly to normal levels. Results, measured with the modified Bishop Rating System, were excellent in 66%, good in 32%, and fair in 2%. There were no poor results. Patients with advanced stages of disease also achieved good results.

Aktueller Stand der Diagnostik und Therapie des Kubitaltunnelsyndroms

The cubital tunnel syndrome is one of the most widespread compression syndromes of a peripheral nerve. In German-speaking countries it is known as the sulcus ulnaris syndrome (retrocondylar groove syndrome), which is anatomically incorrect. The cubital tunnel consists of the retrocondylar groove, the cubital tunnel retinaculum (Lig. arcuatum or Osborne band), the humeroulnar arcade and the deep flexor/pronator aponeurosis. According to Sunderland it can be divided into a primary form (including the ulnar luxation and the epitrocheoanconaeus muscle) and a secondary form caused by deformation or other processes of the elbow joint. The diagnosis has to be confirmed by a thorough clinical examination and nerve conduction studies. Neurosonography and MRI are becoming more and more important with improving resolution and enable the direct identification of morphological changes. Differential diagnosis is essential in atypical cases, especially C8 syndrome and pressure palsy. Double crush (double compression syndrome) may occur. Operative treatment is more effective than conservative treatment, which consists primarily of the prevention of exposure to external noxes. According to actual randomised controlled studies the therapy of choice of the primary form in most cases is the simple in situ decompression of the ulnar nerve in the cubital tunnel. This has to be extended at least up to 5-6 cm distally of the medial epicondyle and can be performed in the open or endoscopic technique, both under local anesthesia. Simple decompression is also the therapy of choice in uncomplicated ulnar luxation and in most post-traumatic cases and other secondary forms. In cases of severe bony or tissue changes of the elbow (especially cubitus valgus) the volar transposition of the ulnar nerve may be indicated. This can be performed in a subcutaneous or submuscular technique. Risks of transposition are impairment of perfusion and, above all, kinking caused by insufficient proximal or distal mobilisation of the nerve has to be avoided. In these cases revision surgery is necessary. The epicondylectomy is not common in our country. Recurrences may occur.

Anatomic characteristics of a fascia and its bands overlying the ulnar nerve in the proximal forearm: a cadaver study

This study describes the characteristics of a fascia overlying the ulnar nerve for 10 cm distal to the midpoint of the retrocondylar groove. A total of 28 cadaver upper extremities were dissected. The ulnar nerve between the flexor carpi ulnaris and flexor digitorum profundus was traced distally underneath a thin fascia. The length of the fascia was measured and examined for the presence of segmental fascial thickenings, referred to as 'Bands'. Two types of fascia were found. In Type I, three Bands were identified within the fascia and the mean length of the fascia was 5.6 cm. In Type II, four Bands were identified and the mean length of the fascia was 7.7 cm. The presence of Bands within the fascia overlying the ulnar nerve in the proximal forearm may require release at the time of decompression, or anterior transposition, of the ulnar nerve at the cubital tunnel.

Cubital tunnel syndrome: anterior transposition as a logical approach to complete nerve decompression.

In it's native position, deep to Osborne's ligament, within the retrocondylar groove of the elbow, the ulnar nerve courses with a significant lever distance posterior to the elbow axis of rotation. In this position, flexion of the elbow places longitudinal traction and local compression forces on the nerve. This biomechanical consideration, as well as variations in anatomy, may potentially contribute to a decrease in the nerve's microcirculation and partial pressure of oxygen, leading to cubital tunnel syndrome. Anterior transposition of the ulnar nerve at the elbow for cubital tunnel syndrome will eliminate natural as well as pathological traction and compression forces; the procedure relieves the nerve of potential microcirculation compromise. Risks of mobilizing the nerve for transposition, however, include iatrogenic ischemia from segmental separation of the nerve from its mesentery-like extrinsic blood supply. Intrinsic interstitial "step-ladder" vessels within the substance of the ulnar nerve allow it to be separated from its extrinsic circulation safely, making anterior transposition a logical and reasonable choice for cubital tunnel syndrome requiring operative intervention.

Intraoperative electroneurography: management of ulnar neuropathy at the elbow.

At the elbow the ulnar nerve may be compressed either in the retrocondylar groove or at the cubital tunnel. Optimal surgical therapy should be directed at the specific site of involvement. Intraoperative electroneurography performed in conjunction with 19 ulnar nerve explorations helped localize the precise site of compression. Of the primary procedures, abnormality was at the retrocondylar groove in 9, cubital tunnel in 4, both locations in 3, and at an unusual distal point in 1; 12 anterior subcutaneous transpositions, 4 cubital tunnel releases, and 1 distal decompression resulted. Intraoperative studies helped identify residual compression in two patients undergoing reexploration. Although routine electrodiagnosis may localize an ulnar neuropathy to the elbow, reliably separating retrocondylar from cubital tunnel compression is more difficult. Preoperatively, percutaneous serial short increment studies were more accurate than simple "inching" in predicting the site of compression.