Volumetric assessment of ulnar nerves in cubital tunnel syndrome with 3D modeling of the MRI and its relationship with electrodiagnostic findings.

BACKGROUND: Thickened nerve cross-sectional areas (CSA) have been investigated in compressive neuropathy, but the longitudinal extent of nerve swelling has yet to be evaluated. We did a volumetric assessment of the ulnar nerve in cubital tunnel syndrome (CuTS) with three-dimensional (3D) magnetic resonance imaging (MRI) modeling and investigated this relationship with clinical and electrodiagnostic parameters. METHODS: We compared 40 CuTS patient elbow MRIs to 46 patient elbow MRIs with lateral elbow epicondylitis as controls. The ulnar nerve was modeled with Mimics software and was assessed qualitatively and quantitatively. The CSA and ulnar nerve volumes were recorded, and the area under the receiver operating characteristic (ROC) curve was calculated for diagnostic performance. We analyzed clinical and electrodiagnostic parameters to investigate their relationship with the 3D ulnar nerve parameters. RESULTS: For the diagnosis of CuTS, the area under the curve value was 0.915 for the largest CSA and 0.910 for the volume in the ROC curve. The optimal cut-off was 14.53 mm2 and 529 mm3 respectively. When electrodiagnostic parameters were investigated, the 3D ulnar nerve volume was significantly inversely associated with motor conduction velocity, although there was no association between the largest CSA and any of the electrodiagnostic parameters. CONCLUSIONS: The 3D ulnar nerve volume, which is an integration or multilevel measurement of CSAs, showed diagnostic usefulness similar to CSA, but it correlated better with conduction velocity, indicating demyelination or early-to-moderate nerve damage in CuTS.

Comparative Analysis of Ultrasound-Assisted Precise Localization vs. Traditional Open Incision in Situ Decompression for the Treatment of Cubital Tunnel Syndrome.

AIM: To retrospectively analyze and compare ultrasound-assisted localization in situ with the traditional, open incision method for treating cubital tunnel syndrome (CuTS). MATERIAL AND METHODS: We retrospectively analyzed 51 patients treated between 2018 and 2022 and categorized them according to treatment method: ultrasound-assisted precise localization in situ decompression (n=21; Cohort 1) and traditional open incision in situ decompression (n=30; Cohort 2). We additionally collected Visual Analogue Scale (VAS) scores, Vancouver Scar Scale (VSS) scores, modified Bishop scores, aesthetic appearance, preoperative Dellon's stage, and analgesics requirements. Additional dependent variables of interest included operation time, hospital stay duration, complications, and reoperation rate. RESULTS: Neither cohort demonstrated significant changes in Dellon's stage, modified Bishop score, or VAS scores between baseline and 6 weeks postoperative. Cohort 1 showed better aesthetics and postoperative VSS and VAS scores than Cohort 1. In addition, Cohort 1 enjoyed a significantly shorter mean operation time and hospital stay. Cohort 1 had 5 (23.80%) complications, including superficial infection (n=1), hematoma (n=1), and incomplete decompression (n=3). Cohort 2 had 9 complications (30.00%), including superficial infection (n=2), hematoma (n=2), and severe scarring (n=5). The partial, incomplete decompression cases in Cohort 1 and the severe scar case in Cohort 2 were treated with reoperation. CONCLUSION: Both procedures effectively treated most cases of CuTS and were associated with good postoperative outcomes. Patients who underwent ultrasound-assisted localization in situ decompression had shorter surgeries and hospital stays, better postoperative aesthetics, better VSS and VAS scores, and required less pain medication during the postoperative period. Traditional open incision in situ produced a more thorough decompression.

CUBITAL TUNNEL SYNDROME DUE TO AN INTRANEURAL GANGLION CYST OF THE ULNAR NERVE.

Cubital tunnel syndrome is the second most common neuropathy of the upper extremity. Cubital tunnel syndrome caused by intraneural ganglion cysts is rare in clinical practice. We present the case of a 71-year-old male patient with a 4-month history of cubital tunnel syndrome of the left elbow due to an intraneural ganglion cyst. After revision of the ulnar nerve and resection of the intraneural cyst nearly complete recovery was achieved within a 5 month follow-up but some sensory deficits of the fifth fingertip. We recommend preoperative ultrasound examination of the cubital tunnel even in cases with clear diagnosis. Ganglion cyst as a cause of cubital tunnel is rare but needs to be diagnosed and treated as soon as possible to prevent irreversible complications.

Diagnosis of Ulnar Neuropathy at the Elbow Using Ultrasound - A Comparison to Electrophysiologic Studies.

PURPOSE: Given the relatively high false negative rate of electrodiagnostic studies (EDX) in patients with clinically diagnosed ulnar neuropathy at the elbow (UNE), we sought to determine whether an alternative objective test could more effectively detect UNE. Additionally, we proposed to determine the relationship between the cross-sectional area (CSA) of the ulnar nerve on ultrasound (US), EDX, and clinical symptoms. METHODS: This was a retrospective study of patients presenting with symptomatic UNE. The performance characteristics of EDX versus ultrasound were calculated using the clinical diagnosis of UNE as the reference standard. Standard EDX studies and US of the ulnar nerve were analyzed. Maximal CSA of the ulnar nerve and EDX severity were analyzed for patients with each combination of US-positive/negative and EDX-positive/negative findings. RESULTS: Analysis was performed on 89 patients and 115 nerves with signs and symptoms of cubital tunnel syndrome. In total, 56 (49%) nerves were diagnosed as mild UNE, 32 (28%) nerves were diagnosed as moderate UNE, 17 (15%) nerves were diagnosed as severe UNE, and 10 (8%) nerves were negative for UNE by EDX. Maximal-maximal CSA was highly correlated with disease severity as determined by nerve conduction studies/electromyography. Compared with EDX+/US+, patients with EDX-/US+ showed higher rates of ulnar sensory loss and elbow tenderness with similar rates of positive Tinel and intrinsic muscle atrophy. In this sample of patients with clinically diagnosed UNE, 91.3% of the patients demonstrated positive EDX studies, whereas 94.8% had a positive US. CONCLUSIONS: Ultrasound is an alternative to EDX that could be incorporated clinically in the diagnosis and management of UNE. Ultrasound was able to consistently detect clinically positive cubital tunnel syndrome demonstrating its utility as a confirmatory or supplemental test to the clinical assessment if one is required. Ultrasound additionally may be able to better identify patients with early stages of UNE with negative EDX findings. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

[Application of ulnar nerve diameter changes examined by HRUS in patients with cubital tunnel syndrome].

OBJECTIVE: To evaluate the value of high-resolution ultrasound the diagnosis and prognosis of cubital tunnel syndrome. METHODS: From January 2018 to June 2019, 47 patients with cubital tunnel syndrome were treated with ulnar nerve release and anterior subcutaneous transposition. There were 41 males and 6 females, aged from 27 to 73 years old. There were 31 cases on the right, 15 cases on the left, and 1 case on both sides. The diameter of ulnar nerve was measured by high-resolution ultrasound pre-and post-operatively, and measured directly during the operation. The recovery status of the patients was evaluated by the trial standard of ulnar nerve function assessment, and the satisfaction of the patients was assessed. RESULTS: All the 47 cases were followed up for an average of 12 months and the incisions healed well. The diameter of ulnar nerve at the compression level was (0.16±0.04) cm pre-operatively, and the diameter of ulnar nerve was (0.23±0.04) cm post-operatively. The evaluation of ulnar nerve function:excellent in 16 cases, good in 18 cases and fair in 13 cases. Twelve months post-operatively, 28 patients were satisfied, 10 patients were general and 9 patients were dissatisfied. CONCLUSION: The preoperative examination of ulnar nerve by high-resolution ultrasound is consistent with the intuitive measurement during operation, and the result of postoperative examination of ulnar nerve by high-resolution ultrasound is consistent with follow-up results. High-resolution ultrasound is an effective auxiliary method for the diagnosis and treatment of cubital tunnel syndrome.

Cubital tunnel syndrome of the ulnar nerve caused by an epineural ganglion cyst: a case report and review of the literature.

BACKGROUND: The ulnar nerve has a long and complex anatomical course, originating from the brachial neural plexus in the neck with nerve trunk formation at the posterior neck triangle, and on to the axilla. This intricate anatomical pathway renders the nerve susceptible to compression, direct injury, and traction throughout its course. Compression of the ulnar nerve is the second most common compression neuropathy of the median nerve adjacent to the wrist joint, after carpal tunnel syndrome. CASE PRESENTATION: A 45-year-old Sudanese housewife complained of progressive right forearm and hand muscle wasting, pain, and neuropathic symptoms. She was diagnosed with right-sided cubital tunnel syndrome. The diagnosis was derived intraoperatively from a nerve conduction study suggesting the level of conduction block and recommending decompression. Magnetic resonance imaging was not done preoperatively due to financial limitations. An epineural ganglion (15 × 20 mm2) compressing and flattening the ulnar nerve was diagnosed intraoperatively. Surgical decompression of the ulnar nerve and removal of the epineural ganglion achieved a remarkable postoperative result and pleasing outcome. CONCLUSION: Surgical management is the cornerstone of treatment for compressive neuropathy and ranges from simple nerve decompression to complex neurolysis procedures and nerve transposition to adjust the anatomical course of the nerve.

Changes in Ultrasound Measurements of the Ulnar Nerve at Different Elbow Joint Positions in Patients with Cubital Tunnel Syndrome.

Ultrasound imaging (US) is increasingly being used in the diagnosis of entrapment neuropathies. The aim of the current study was to evaluate changes in stiffness (shear modulus), cross-sectional area (CSA), and trace length (TRACE) of the ulnar nerve in patients with cubital tunnel syndrome (CuTS), with shear wave elastography (SWE). A total of 31 patients with CuTS were included. CSA, shear modulus, and TRACE examinations were performed in the SWE mode in four positions of the elbow: full extension, 45° flexion, 90° flexion, and maximum flexion. There were significant side-to-side differences in the ulnar nerve elasticity value at 45°, 90°, and maximal elbow flexion (all, p < 0.001) but not at elbow extension (p = 0.36). There were significant side-to-side differences in the ulnar nerve CSA value at each elbow position (all, p < 0.001). There were significant side-to-side differences in the ulnar nerve trace value at each elbow position (all, p < 0.001). The symptomatic ulnar nerve in patients with CuTS exhibited greater stiffness (shear modulus), CSA, and TRACE values, compared with the asymptomatic side. US examinations (shear modulus, CSA, and TRACE evaluation) of the ulnar nerve can be helpful in supporting and supplementing the diagnosis in patients with CuTS.

Morphological Changes of Medial Epicondyle-Olecranon Ligament and Ulnar Nerve in the Cubital Tunnel Syndrome: An Ultrasonic Study.

OBJECTIVE: Few studies have performed detailed ultrasound measurements of medial epicondyle-olecranon (MEO) ligament that cause the entrapment of ulnar nerve. This study aims to comprehensively evaluate dynamic ultrasonographic characteristics of MEO ligament and ulnar nerve for clinical diagnosis and accurate treatment of cubital tunnel syndrome (CuTS). METHODS: Thirty CuTS patients (CuTS group) and sixteen healthy volunteers (control group) who underwent ultrasound scanning from October 2016 to October 2020 were retrospectively collected, with 30 elbows in each group. Primary outcomes were thickness at six points, length and width of MEO ligament. Secondary outcomes were thickness of ulnar nerve under MEO ligament at seven parts and the cross-sectional area (CSA) of ulnar nerve at proximal end of MEO ligament (P0 mm ). The thickness of MEO ligament and ulnar nerve in different points of each group was compared by one-way ANOVA analysis with Bonferroni post hoc test, other outcomes were compared between two elbow positions or two groups using independent-samples t test. RESULTS: Thickness of MEO ligament in CuTS group at epicondyle end, midpoint in transverse view, olecranon end, proximal end, midpoint in axial view, and distal end was 0.67 ± 0.31, 0.37 ± 0.18, 0.89 ± 0.35, 0.39 ± 0.21, 0.51 ± 0.38, 0.36 ± 0.25 at elbow extension, 0.68 ± 0.34, 0.38 ± 0.27, 0.77 ± 0.39, 0.32 ± 0.20, 0.48 ± 0.22, 0.32 ± 0.12 (mm) at elbow flexion, respectively. Compared with control group, they were significantly thickened except for proximal end at elbow flexion. MEO ligament thickness at epicondyle end and olecranon end was significantly larger than midpoint in two groups. No significant difference was found in length and width of MEO ligament among different comparisons. Ulnar nerve thickness at 5 mm proximal to MEO ligament (P5 mm , 3.25 ± 0.66 mm) was significantly increased than midpoint of MEO ligament (Mid), distal end of MEO ligament (D0 mm ), 5 mm (D5 mm ), 10 mm (D10 mm ) distal to MEO ligament at extension in CuTS group. Compared with control group, ulnar nerve thickness at P5 mm in CuTS group was significantly increased at extension position, at D5 mm and D10 mm was significantly decreased at flexion position. CSA of ulnar nerve at extension position (14.44 ± 4.65 mm2 ) was significantly larger than flexion position (11.83 ± 3.66 mm2 ) in CuTS group, and CuTS group was significantly larger than control group at two positions. CONCLUSIONS: MEO ligament in CuTS patients was thickened, which compressed ulnar nerve and caused its proximal end swelling. Ultrasonic image of MEO ligament thickness was a significant indicator for CuTS and can guide surgeons in selecting the appropriate treatment.

The diagnostic role of ultrasound in cubital tunnel syndrome for patients with a previous cubital tunnel surgery.

BACKGROUND: Ultrasound is widely used in the diagnosis of peripheral nerve compressions. Nevertheless, the role of ultrasound, and in particular the cross-sectional area (CSA) measurements, in the diagnosis of cubital tunnel syndrome (CuTS) is debatable, especially in patients who have had previous surgeries. We evaluated the diagnostic value of ultrasound and CSA measurements in a heterogenous group of CuTS patients suffering from persisting or recurrent CuTS after a previous surgical intervention. METHODS: All patients with persisting or recurrent CuTS after previous surgery, who received a nerve ultrasound with or without CSA measurements in a tertiary referral center between 2015 and 2022, were included. Median CSA was calculated at five locations from the upper arm to the wrist. The sensitivity of ultrasound and electrodiagnostic studies and the correlation between both diagnostic tools were calculated. RESULTS: Thirty-seven nerves from 35 patients who received nerve ultrasound, of which 21 nerves from 19 patients who received additional CSA measurements, were included. Ultrasound indicated signs of persisting or recurrent compression in 73.0% of patients, and ulnar swelling based on CSA measurements was found in 71.4% of patients. Electrodiagnostic testing was positive in 40.7% of patients. CuTS diagnosis was supported by both electrodiagnostic studies and CSA in only 34.6% of patients. CONCLUSIONS: CSA and electrodiagnostic testing in patients with persistent or recurrent symptoms after previous surgery did not correlate well, and the sensitivity of both tests was lower than in diagnostic accuracy studies. Ultrasound was found to be useful in evaluating ulnar nerves after previous surgery.

Dynamic analysis of the ulnar nerve and cubital tunnel morphology using ultrasonography: a cadaveric study.

BACKGROUND: The causes of ulnar neuropathy at the elbow are unclear. The authors hypothesized that the humeral trochlea protrudes into the cubital tunnel during elbow flexion and causes a dynamic morphologic change of the ulnar nerve in the cubital tunnel. METHODS: An ultrasonic probe was fixed to the ulnar shafts of 10 fresh cadavers with an external fixator, and dynamic morphology of the cubital tunnel and ulnar nerve was observed. The distance from the Osborne band to the trochlea (OTD), distance from ulnar nerve center to the trochlea (UTD), and the short- and long-axis diameters of the nerve at 30°, 60°, 90°, and 120° of elbow flexion were recorded. We compared the OTD, UTD, and the flattening of the ulnar nerve at the different angles of flexion using single-factor analysis of variance. Correlation between the ulnar nerve flattering, OTD, and UTD was examined using Spearman correlation coefficient. A P value less than .05 was used to denote statistical significance. RESULTS: Flattening of the ulnar nerve progressed with increasing elbow flexion and was significantly different between 0° and 60°, 90°, and 120° (P = .03 at 60°, P < .01 at 90° and 120°). OTD decreased with elbow flexion, and there was a significant difference at all elbow flexion angles (all P < .01). UTD decreased significantly from 0° flexion to 90° flexion (P = .03). Flattening of the nerve was significantly correlated with the OTD (r = 0.66, P < .01). CONCLUSIONS: A positive correlation was found between the protrusion of the humeral trochlea into the cubital tunnel during elbow flexion and ulnar nerve flattening using cadaveric elbow and ultrasonography.

Dynamic Evaluation of Intraneural Microvascularity of the Ulnar Nerve Using Contrast-Enhanced Ultrasonography in Patients With Cubital Tunnel Syndrome.

PURPOSE: The purpose of this study was to compare the intraneural microvascular patterns of the ulnar nerve at 2 elbow flexion angles in asymptomatic volunteers and patients with cubital tunnel syndrome (CuTS) and to evaluate the effects of surgery on the microvascular pattern in patients with CuTS by using contrast-enhanced ultrasonography (CEUS). METHODS: This study included 10 elbows in 10 asymptomatic volunteers (control group) and 10 elbows in 10 patients with CuTS who underwent anterior subcutaneous transposition of the ulnar nerve (CuTS group). The CuTS group underwent clinical and electrophysiologic examinations and CEUS before surgery and at 1, 2, and 3 months after surgery. The intraneural enhancement pattern was calculated as an area under the curve (AUC) value in the entrapment site of the ulnar nerve within the cubital tunnel and in the area 1 cm proximal to the site (proximal site) at elbow flexion angles of 20° and 110°. RESULTS: Serial electrophysiologic examinations showed improvements at 1, 2, and 3 months after surgery compared with before surgery. In the control group, the AUC values of the central part of the cubital tunnel and proximal sites showed no substantial changes with the increase in elbow flexion. In the CuTS group, the AUC in the proximal site at 110° of elbow flexion was decreased compared with that at 20° of flexion before surgery. The AUC values for both the entrapment and proximal sites at 20° and 110° of elbow flexion were the most increased at 2 months after surgery compared with before surgery. CONCLUSIONS: Increased elbow flexion in patients with CuTS influences the intraneural blood flow of the ulnar nerve. Surgery for CuTS alters the intraneural blood flow. CLINICAL RELEVANCE: Quantitative evaluation of the intraneural blood flow of the ulnar nerve using CEUS may be a new supplementary diagnostic tool for CuTS and an indicator for the evaluation of postoperative recovery from nerve damage.

Ultrasound-guided percutaneous electrical stimulation for a patient with cubital tunnel syndrome: a case report with a one-year follow-up.

OBJECTIVE: Patients with ulnar neuropathy usually experience sensory disturbances, weakness, and decreased function; however, optimal treatment approaches for this condition are not conclusive. CASE DESCRIPTION: A 48-year-old male with cubital tunnel syndrome was previously managed with a multimodal approach including splinting, neural mobilizations, and exercises with no change in symptoms. Approximately 1 year after the initial onset, he received three sessions of ultrasound-guided percutaneous electrical stimulation (PENS) and self-neural glides as a home program. OUTCOMES: After PENS intervention, the patient experienced a dramatic improvement in function and symptoms as measured by the Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH) and self-reported version of the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale as outcomes. These improvements were maintained after 1, 3, 6, and 12 months. The patient also experienced self-perceived improvement in his condition as measured by the Global Rating of Change (GROC) at each follow-up. CONCLUSION: A patient with ulnar nerve entrapment at the elbow did not respond to a multimodal conservative care for the previous year. Once the patient was treated with ultrasound-guided PENS targeting the ulnar nerve, full functional recovery and resolution of symptoms were documented. Future clinical studies should examine the effects of PENS in managing neural entrapment syndromes on a statistically powered sample of patients.

Decision Making via 3D Computed Tomography in the Surgical Treatment of Cubital Tunnel Syndrome: Surgical Technique and Results.

AIM: To investigate the importance of elbow 3D computed tomography in surgical planning when deciding on the treatment surgical treatment method of the ulnar nerve entrapment in the cubital tunnel. MATERIAL AND METHODS: In this study, 21 patients with cubital tunnel syndrome in our clinic were included and retrospectively analyzed. All of the patients were diagnosed with EMG, and surgical planning was performed based on the anatomy of the cubital tunnel diagnosed via 3D computed tomography. In addition to the classical simple decompression of the ulnar nerve, 15 patients underwent cubital tunnel reconstruction with high-speed drill, whereas 6 patients underwent ulnar nerve anterior subcutaneous transposition. The results were evaluated based on the modified Wilson & Krout criteria. RESULTS: Fourteen of the patients were female and seven were male. The average age was 42.2 years. Fifteen patients underwent simple decompression of the ulnar nerve and cubital tunnel reconstruction. Transposition was performed in six patients. The patients were followed up for an average of 107.5 months (3-144). Based on the Wilson & Krout criteria, excellent results were obtained in 14 patients (66.7%), good results in 6 (28.6%), and poor results in 1 (4.8%). CONCLUSION: The evaluation of the cubital tunnel via 3D computed tomography before the operation is effective in determining the optimal surgical technique and obtaining more successful clinical results. The cubital tunnel reconstruction in addition to simple decompression increases surgical success and minimizes complications and the possibility of relapse due to the fact that the nerve remains in its natural position.

Comment to: The utility of ultrasound examination in cubital tunnel syndrome caused by heterotopic ossification.

Ultrasound (US) could visualize the pathological anatomy of HO and the enlargement site and compression location of the nerve in the cubital tunnel [1]. We read with great interest the article of Jacisko et al[2]. In addition, we report rare US images of HO in direct contact with the swollen ulnar nerve in the cubital tunnel that was not detected by plain radiography. A 60-year-old female presented with a six-month history of elbow pain. Her pain was located at the medial side of the right elbow joint and accompanied by numbness of the fifth finger. She had a history of excessive manual labor due to her occupation as a gardener over the past few decades. The numbness began with the fifth finger initially and gradually extended toward the medial side of the elbow joint. US images showed hyperechoic masses causing acoustic shadowing, in direct contact with the ulnar nerve in the cubital tunnel. The HO seems to be related to compression of the ulnar nerve. The ulnar nerve was swollen (Figure 1-a, b). The maximal cross-sectional-area was 0.10 cm2. Plain elbow radiographs demonstrated osteophyte formation in the coronoid process of the ulna, the coronoid fossa of the humerus, and in the radial head (Figure 1-c). Radiographic imaging showed no heterotopic bone formation in the soft tissues surrounding the medial side of the right elbow. We performed US-guided perineural injection with a mixture of 1 cc of 10 mg triamcinolone and 3 cc of 0.2 % ropivacaine. Her pain and numbness gradually diminished with no adverse effects. Her pain reduced by 70% after two weeks, with pain improvement sustained for 6 months after the injection. Jacisko et al[2]have presented some diagnostic US imaging on neuropathy caused by HO located close to the ulnar nerve in the cubital tunnel. Especially, this case showed definite heterotopic bone formation in the soft tissue surrounding the medial side of the elbow on plain radiography. The classic sonographic patterns of HO were defined by the presence of central hypoechoic area surrounded by foci of calcification [3, 4]. The distortion of normal soft tissue and the formation of hypoechoic areas, with or without foci of calcification can also be shown as early signs[3, 4]. The use of US for HO is highly sensitive and provides an earlier diagnosis compared with other radiologic modalities [3-5]. It can be an effective treatment strategy and may improve the prognosis of neuropathy. We highlight that US evaluation can provide early diagnostic information about ulnar nerve morphology and various HO formations even if plane radiographs did not show heterotopic bone formation in the soft tissues surrounding the medial side of the elbow.

High-Resolution Ultrasound in the Diagnosis and Surgical Management of Ulnar Neuropathy at the Elbow.

High-resolution ultrasound (HRU) has recently demonstrated the potential to facilitate diagnosis and treatment of upper extremity compression neuropathy. The authors hypothesized that HRU can improve preoperative evaluation of ulnar neuropathy at the elbow (UNE) and that changes in ulnar nerve cross-sectional area (CSA) after cubital tunnel release may correlate with outcomes. Nineteen adult patients diagnosed with UNE who were scheduled for surgical decompression by a single hand surgeon were enrolled. Electrodiagnostic (EDX) testing, HRU of the ulnar nerve, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, and McGowan grade were obtained pre- and postoperatively. Fourteen patients completed the study. Statistically significant improvements were found in CSA measurements and QuickDASH scores. High-resolution ultra-sound was found to confirm UNE in all 7 patients with positive results on EDX, and additionally detected UNE in 3 of 6 patients with negative results on EDX and in 1 patient with equivocal (nonlocalized) EDX testing. All 4 of these additional HRU-detected cases improved clinically and by CSA measurements after surgery. In this series, HRU was superior to EDX testing in the diagnosis of UNE and demonstrated objective improvement in ulnar nerve CSA after successful cubital tunnel release. This modality, which is better tolerated, less costly, and less time-consuming than EDX testing or magnetic resonance imaging, should therefore be considered in the diagnosis and surgical management of UNE, particularly in cases with negative or equivocal results on EDX testing, or when outcomes are suboptimal. [Orthopedics. 2021;44(5):285-288.].

Diffusion tensor imaging in cubital tunnel syndrome.

Cubital tunnel syndrome (CuTS) is the 2nd most common compressive neuropathy. To improve both diagnosis and the selection of patients for surgery, there is a pressing need to develop a reliable and objective test of ulnar nerve 'health'. Diffusion tensor imaging (DTI) characterises tissue microstructure and may identify differences in the normal ulnar from those affected by CuTS. The aim of this study was to compare the DTI metrics from the ulnar nerves of healthy (asymptomatic) adults and patients with CuTS awaiting surgery. DTI was acquired at 3.0 T using single-shot echo-planar imaging (55 axial slices, 3 mm thick, 1.5 mm2 in-plane) with 30 diffusion sensitising gradient directions, a b-value of 800 s/mm2 and 4 signal averages. The sequence was repeated with the phase-encoding direction reversed. Data were combined and corrected using the FMRIB Software Library (FSL) and reconstructed using generalized q-sampling imaging in DSI Studio. Throughout the length of the ulnar nerve, the fractional anisotropy (FA), quantitative anisotropy (QA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) were extracted, then compared using mixed-effects linear regression. Thirteen healthy controls (8 males, 5 females) and 8 patients with CuTS (6 males, 2 females) completed the study. Throughout the length of the ulnar nerve, diffusion was more isotropic in patients with CuTS. Overall, patients with CuTS had a 6% lower FA than controls, with the largest difference observed proximal to the cubital tunnel (mean difference 0.087 [95% CI 0.035, 0.141]). Patients with CuTS also had a higher RD than controls, with the largest disparity observed within the forearm (mean difference 0.252 × 10-4 mm2/s [95% CI 0.085 × 10-4, 0.419 × 10-4]). There were no significant differences between patients and controls in QA, MD or AD. Throughout the length of the ulnar nerve, the fractional anisotropy and radial diffusivity in patients with CuTS are different to healthy controls. These findings suggest that DTI may provide an objective assessment of the ulnar nerve and potentially, improve the management of CuTS.

Primary elbow osteoarthritis presenting as ulnar nerve palsy with claw hand.

A 59-year-old woman was referred with weakness, paraesthesia, numbness and clawing of the little and ring fingers for the last 2 years. MRI of the cervical spine was normal and nerve conduction velocity revealed abnormality of the ulnar nerve. Ultrasound and MRI showed medial osteophytes and effusion of the elbow joint with stretched and thinned ulnar nerve in the cubital tunnel. The patient underwent release and anterior transposition of the ulnar nerve with significant relief of symptoms.