Double entrapment neuropathy of the ulnar nerve at the elbow and the wrist : double crush syndrome?

BACKGROUND: Double crush syndrome refers to a nerve in the proximal region being compressed, affecting its proximal segment. Instances of this syndrome involving ulnar and cubital canals during ulnar neuropathy are rare. Diagnosis solely through clinical examination is challenging. Although electromyography (EMG) and nerve conduction studies (NCS) can confirm neuropathy, they do not incorporate inching tests at the wrist, hindering diagnosis confirmation. We recently encountered eight cases of suspected double compression of ulnar nerve, reporting these cases along with a literature review. METHODS: The study included 5 males and 2 females, averaging 45.6 years old. Among them, 4 had trauma history, and preoperative McGowan stages varied. Ulnar neuropathy was confirmed in 7 cases at both cubital and ulnar canal locations. Surgery was performed for 4 cases, while conservative treatment continued for 3 cases. RESULTS: In 4 cases with wrist involvement, 2 showed ulnar nerve compression by a fibrous band, and 1 had nodular hyperplasia. Another case displayed ulnar nerve swelling with muscle covering. Among the 4 surgery cases, 2 improved from preoperative McGowan stage IIB to postoperative stage 0, with significant improvement in subjective satisfaction. The remaining 2 cases improved from stage IIB to IIA, respectively, with moderate improvement in subjective satisfaction. In the 3 cases receiving conservative treatment, satisfaction was significant in 1 case and moderate in 2 cases. Overall, there was improvement in hand function across all 7 cases. CONCLUSION: Typical outpatient examinations make it difficult to clearly differentiate the two sites, and EMG tests may not confirm diagnosis. Therefore, if a surgeon lacks suspicion of this condition, diagnosis becomes even more challenging. In cases with less than expected postoperative improvement in clinical symptoms of cubital tunnel syndrome, consideration of double crush syndrome is warranted. Additional tests and detailed EMG tests, including inching tests at the wrist, may be necessary. We aim to raise awareness double crush syndrome with ulnar nerve, reporting a total of 7 cases to support this concept.

An electrodiagnostic grading system for ulnar neuropathy at the elbow.

INTRODUCTION: Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy. Our goal was to create and analyze a grading system for UNE electrodiagnostic severity. METHODS: We retrospectively analyzed EMG reports with UNE. We then classified 112 limbs as having mild, moderate, or severe grade UNE based on electrodiagnostic findings. The association between presenting symptoms and signs, EMG findings, treatment type, and electrodiagnostic grade was statistically analyzed. RESULTS: Seventeen limbs (15.2%) had mild, 80 (71.4%) had moderate, and 15 (13.4%) had severe UNE. Symptoms (P = .016), exam findings (P < .001), and treatment type (P = .043) were significantly associated with electrodiagnostic grade. DISCUSSION: Our UNE grading system was significantly related to symptoms, physical exam, and treatment selection and may be useful to measure electrodiagnostic severity.

Hypothenar Hammer Syndrome with Ulnar Nerve Neuropathy.

Hypothenar hammer syndrome is a rare medical condition that is usually associated with repetitive hand trauma. In this article, we delineate the importance of the nerve conduction velocity study to help determine objectively whether neuropathy is significant to the point that surgical means should be considered in absence of obvious ischemic change.

Efficacy of shortwave diathermy in ulnar nerve entrapment at the elbow: a double-blind randomized controlled clinical trial.

OBJECTIVE: To investigate the efficacy of shortwave diathermy in treatment of ulnar nerve entrapment at the elbow. DESIGN: The study was a double blind, randomized controlled clinical trial. SETTING, PARTICIPANTS: A total of 76 adult patients diagnosed with ulnar nerve entrapment at the elbow clinically and electrophysiologically, were randomly assigned into two groups. Patients were evaluated at baseline, after completing treatment and 1 and 3 months after treatment. Physical examination, quick-DASH (disabilities of arm, shoulder, hand) and SF-36 (short form) questionnaires for daily life activities, dynamometer for grip strength, and visual analog scale for pain were used. INTERVENTION: A total of 10 sessions of shortwave diathermy were applied to patients in treatment group as five sessions/week, 2 weeks. Control group was given placebo shortwave diathermy. Both groups were given elbow splints and informed to avoid symptom provoking activities. MAIN OUTCOME MEASURES: Visual analog scale, grip strength, SF-36, and quick-DASH results. RESULTS: Out of 76 patients, 61 of them completed the study where n = 31 for treatment group and n = 30 for control group. Mean age was 46.18 ± 13.45 years. There were 32 (52.5%) women and 29 (47.5%) men. The p values between groups 3 months after intervention for visual analog scale, quick-DASH, SF-36 questionnaire, and dynamometer were 0.669, 0.277, 0.604, and 0.126, respectively (p > 0.05). CONCLUSION: Application of shortwave diathermy to patients with ulnar nerve neuropathy at the elbow was not associated with any difference in outcome.

Innervation of the anconeus epitrochlearis muscle: MRI and cadaveric studies.

Ulnar neuropathy at the cubital tunnel is common. However, a rare form of ulnar neuropathy here is due to compression from an accessory muscle, the anconeus epitrochlearis. Reports in the literature regarding the details of this muscle's innervation are vague, so the aim of the present study was to characterize this anatomy more clearly. This was a combined review of magnetic resonance imaging (MRI) from patients with an anconeus epitrochlearis and ulnar neuropathy and cadaveric dissections to characterize the innervation of this variant muscle. A review of 11 patients and three reports of ulnar neuropathy and an anconeus epitrochlearis in the literature revealed no MRI changes consistent with acute denervation of this muscle. However, in two cases, there were signs of chronic denervation of the muscle. Dissection of five cadavers revealed that the nerve supply to the anconeus epitrochlearis originated proximal to the medial epicondyle, traveled parallel to the ulnar nerve, terminated on the deep aspect of this muscle, and had a mean length of 60 mm. This clinicoanatomical study provides evidence that the innervation of the anconeus epitrochlearis is proximal to the muscle and on its deep aspect. Clin. Anat. 32:218-223, 2019. © 2018 Wiley Periodicals, Inc.

Comparison of Ultrasonography and Short-Segment Nerve Conduction Study in Ulnar Neuropathy at the Elbow.

OBJECTIVE: To assess the correlation between ultrasonographic and electrodiagnostic findings to determine the localization of the ulnar trapping at the elbow. DESIGN: Cross-sectional and noninterventional trial. SETTING: Physical medicine and rehabilitation department of a teaching hospital. PARTICIPANTS: Patients (N=14) diagnosed with ulnar nerve entrapment using short-segment nerve conduction study. INTERVENTIONS: The elbow area was divided into 4 segments with 2-cm intervals. All patients underwent ultrasonographic and electrodiagnostic examinations. MAIN OUTCOME MEASURES: The nerve conduction velocity (NCV) of each segment was measured. The cross-sectional area (CSA) of the ulnar nerve was measured at 5 levels. The proximal CSA/distal CSA ratio (PDR) was calculated by proportioning the CSA values for each segment. The highest PDR was accepted as a trapping segment, whereas the segment with the lowest NCV was accepted electrophysiologically (provided it was <50m/s). RESULTS: A total of 80 PDR and NCV measurements were taken from 20 elbows. A statistically significant negative correlation (r=-.554; P<.001) was found between general PDR and NCV values. When we assumed that the NCV value <50m/s as the criterion standard for diagnosis, the cutoff value for the PDR was found to be 1.08, with a sensitivity of 70% and a specificity of 92.5%. The minimum NCV value and the maximum PDR value were mostly seen in the third segment compatible with the cubital tunnel. CONCLUSIONS: Ultrasonography seems to be advantageous because it is more comfortable for the patient and requires shorter time than does electroneuromyography. To our knowledge, this is the first study to detect ulnar nerve entrapment by using not only CSA but also PDR as a ratio method with ultrasound.

Ultrasound biomechanical anatomy of the soft structures in relation to the ulnar nerve in the cubital tunnel of the elbow.

BACKGROUND: Chronic ulnar nerve entrapment worsened by elbow flexion is the most common injury, but rare painful conditions may also be related to ulnar nerve instability. The posterior bundle of the medial collateral ligament (pMCL) and the retinaculum, respectively form a soft floor and a ceiling for the cubital tunnel. The aim of our study was to dynamically assess these soft structures of the cubital tunnel focusing on those involved in the biomechanics of the ulnar nerve. METHODS: Forty healthy volunteers had a bilateral ultrasonography of the cubital tunnel. Elbows were scanned in full extension, 45° and 90°, and maximal passive flexion. Morphological changes of the nerve and related structures were dynamically assessed on transverse views. RESULTS: Both the pMCL and the retinaculum tightened with flexion. During elbow flexion, the tightening of the pMCL superficially moved the ulnar nerve remote from the osseous floor of the retroepicondylar groove. A retinaculum was visible in all 69 tunnels with stable nerves (86.3%), tightened in flexion, but absent in 11 tunnels with unstable nerves (13.7%). The retinaculum was fibrous in 60 elbows and muscular in nine, the nine muscular variants did not significantly influence the biomechanics of stable nerves. Stable nerves flattened in late flexion between the tightened pMCL and retinaculum, whereas unstable nerves transiently flattened when translating against the anterior osseous edge of the groove. CONCLUSION: The retinaculum and the pMCL are key structures in the biomechanics of the ulnar nerve in the cubital tunnel of the elbow.

Ulnar tunnel syndrome.

Ulnar neuropathy at or distal to the wrist, the so-called ulnar tunnel syndrome, is an uncommon but well-described condition. However, diagnosis of ulnar tunnel syndrome can be difficult. Paresthesias may be nonspecific or related to coexisting pathologies, such as carpal tunnel syndrome, cubital tunnel syndrome, thoracic outlet syndrome, C8-T1 radiculopathy, or peripheral neuropathy, which makes accurate diagnosis challenging. The advances in electrodiagnosis, ultrasonography, computed tomography, and magnetic resonance imaging have improved the diagnostic accuracy. This article offers an updated view of ulnar tunnel syndrome as well as its etiologies, diagnoses, and treatments.

Anatomy of Guyon's canal - a systematic review.

Carpal tunnel syndrome is the first on the list of peripheral nerve lesions in the upper limb. Most of the anatomical facts about this syndrome are widely known. The Guyoun's canal is the second reason for compression syndrome in the wrist. Anatomy of this is region still remains controversial. This is why authors tried to compile some latest findings accompanied by their own observation, and added some clinical notes, which might be useful both for orthopedic surgeons and well as for representatives of basic sciences.

[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.

Ulnar nerve lesion at the wrist related to pisotriquetral joint arthropathy.

INTRODUCTION: Ulnar nerve lesions at the wrist (UNLW) are always difficult to localize clinically and sometimes electrophysiologically. Finding conduction block when studying ulnar motor nerve conduction (CB) across the wrist is sometimes the only way to demonstrate that the ulnar deep motor branch (UDMB) is entrapped. METHODS: An elderly woman who had bilateral carpal tunnel syndrome (CTS) and thumb osteoarthritis for many years experienced worsening of left hand impairment recently. RESULTS: Electrodiagnostic and ultrasound examinations revealed an acute and severe UDMB lesion related to pisotriquetral joint effusion. The patient received a local injection of a corticosteroid that provided rapid recovery. CONCLUSIONS: The diagnosis of UDMB lesion is especially difficult when CTS coexists, but CTS may allow for early diagnosis, if CB at the wrist is not overlooked. Chondrocalcinosis was responsible for the systemic inflammation, the CTS, the pisotriquetral joint effusion, and the UDBM compression, which has not been reported previously.

Development and validation of the patient-rated ulnar nerve evaluation.

BACKGROUND: Compression neuropathy at the elbow causes substantial pain and disability. Clinical research on this disorder is hampered by the lack of a specific outcome measure for this problem. A patient-reported outcome measure, The Patient-Rated Ulnar Nerve Evaluation (PRUNE) was developed to assess pain, symptoms and functional disability in patients with ulnar nerve compression at the elbow. METHODS: An iterative process was used to develop and test items. Content validity was addressed using patient/expert interviews and review; linking of the scale items to International Classification of Functioning, Disability, and Health (ICF) codes; and cognitive coding of the items. Psychometric analysis of data collected from 89 patients was evaluated. Patients completed a longer version of the PRUNE at baseline. Item reduction was performed using statistical analyses and patient input to obtain the final 20 item version. Score distribution, reliability, exploratory factor analysis, correlational construct validity, discriminative known group construct validity, and responsiveness to change were evaluated. RESULTS: Content analysis indicated items were aligned with subscale concepts of pain and sensory/motor symptoms impairments; specific upper extremity-related tasks; and that the usual function subscale provided a broad view of self-care, household tasks, major life areas and recreation/ leisure. Four subscales were demonstrated by factor analysis (pain, sensory/motor symptoms impairments, specific activity limitations, and usual activity/role restrictions). The PRUNE and its subscales had high reliability coefficients (ICCs>0.90; 0.98 for total score) and low absolute error. The minimal detectable change was 7.1 points. It was able to discriminate between clinically meaningful subgroups determined by an independent evaluation assessing work status, residual symptoms, motor recovery, sensory recovery and global improvement) p<0.01. Responsiveness was excellent (SRM=1.55). CONCLUSION: The PRUNE is a brief, open-access, patient-reported outcome measure for patients with ulnar nerve compression that demonstrates strong measurement properties.

Relation between electrophysiological findings and diffusion weighted magnetic resonance imaging in ulnar neuropathy at the elbow.

AIM: As only a limited number of studies have used diffusion-weighted imaging (DWI) and conventional magnetic resonance imaging (MRI) in patients with ulnar neuropathy at the elbow (UNE), the present study aimed to investigate the diagnostic value of the non-invasive DWI technique in patients with UNE. METHODS: A total of 26 elbows in 19 healthy controls (age range: 22-56 years) with no symptoms and 24 elbows in 21 symptomatic patients (age range: 21-46 years) with cubital tunnel syndrome underwent DWI. The electrophysiological and clinical criteria for the diagnosis of UNE were examined. RESULTS: No pathological signal from the ulnar nerve was detected in the healthy controls, whereas there was an increase in signals on DWI in all patients with UNE. On T2-weighted (T2W) imaging, there was increased signal intensity in 20 elbows, while low signal intensity was observed in the remaining four. A positive correlation was found between disease duration and presence of hyperintensity (P=0.044, r=0.42) on T2W images. CONCLUSION: DWI can be used together with electrophysiological methods for the diagnosis of UNE. Furthermore, DWI might be preferred in some cases, as it is non-invasive compared with the electrophysiological method for UNE diagnosis.

Laxity of the ulnar nerve during elbow flexion and extension.

PURPOSE: To evaluate the dynamic anatomy of the ulnar nerve at the elbow. METHODS: We studied 11 fresh cadavers. We placed metal clips on the ulnar nerve at three locations: at the medial epicondyle (point A), 3 cm proximal to the epicondyle (point B), and 14 cm proximal to the epicondyle (point C). The distances from the medial epicondyle to points A, B, and C on the ulnar nerve and between each pair of points were measured in full elbow extension and flexion. RESULTS: With full elbow flexion, there was no movement of the ulnar nerve at point A (adjacent to the medial epicondyle). Point A and the adjacent distal ulnar nerve moved as a unit with the forearm around the medial epicondyle. Proximal to the cubital tunnel, there was significant ulnar nerve excursion (P < .01) at points B (0.7 ± 0.3 cm) and C (0.2 ± 0.2 cm). There was differential excursion of the ulnar nerve at points B and C relative to the medial epicondyle. The distances between the markers revealed that the nerve did not stretch to account for the discrepant distances of the 3 points, but a slack region of the nerve proximal to the medial epicondyle was taken up with flexion. Release of the intermuscular septum and the canal of Struthers did not influence movement of the nerve. CONCLUSIONS: With elbow flexion, the ulnar nerve did not move appreciably in the distal-proximal direction directly at the cubital tunnel, but maximal excursion was in the fatty region proximal to the elbow. This slack region of the nerve was taken up during flexion, whereas only 2 mm of motion occurred through the canal of Struthers. The slack region might predispose to subluxation of the nerve. Conversely, decreased laxity might result in increased traction of the nerve, contributing to cubital tunnel syndrome. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

[The results of ulnar nerve decompression in Guyon's canal syndrome]. / Výsledky dekomprese nervus ulnaris u syndromu Guyonova tunelu.

PURPOSE OF THE STUDY: The aim of the study was to evaluate a group of patients treated for Guyon's canal syndrome with analysis of the cause for and outcome of surgery. MATERIAL AND METHODS: The group comprised 13 patients operated on for compressive neuropathies of the ulnar nerve in the canal of Guyon in the period from 2007 to 2010. The clinical parameters evaluated were the adduction strength of the fifth digit, degree of interosseous primus muscle hypotrophy and degree of hypoesthesia in the area innervated by the ulnar nerve. EMG parameters included motor and sensory nerve conduction through Guyon's canal. Patients' subjective evaluations of the treatment outcomes were also recorded. The results were not compared with a control group. RESULTS: Post-operative improvements in all clinical and EMG parameters were significant (p=0.02-0.003). All but one patient (90%) reported an improved subjective condition after surgery; on the other hand, pre-operative severe impairment of motor nerve conduction highly affected the post-operative motor function. Guyon's canal syndrome accounted for 0.8% of all compressive neuropathies of the upper extremity in our patients. DISCUSSION: Ulnar nerve compression at the wrist is a relatively rare condition amongst the compressive neuropathies of the upper extremity, and literature data concerning this disease are very few. Although many causes of ulnar nerve compression at the wrist have been reported, only one of our patients had ganglion. We conclude that the majority of cases can be diagnosed as a "neuritis" due to chronic microtrauma produced by pressure of a hypertrophic palmar ligament. CONCLUSIONS: Syndrome of Guyon's canal can easily be treated by surgery. As in other compression syndromes, the sooner a surgical decompression is performed, the better outcomes are achieved.

Morphology of the cubital tunnel: an anatomical and biomechanical study with implications for treatment of ulnar nerve compression.

PURPOSE: The purpose of this study is to provide a thorough understanding of the anatomy of the cubital tunnel and to outline specific anatomical parameters of the cubital tunnel retinaculum (CuTR) that might aid in the management of ulnar nerve problems. The hypotheses of this study are (1) that the nerve elongates with elbow flexion and (2) that the cross-sectional area of the cubital tunnel is inversely proportional to the degree of elbow flexion. METHODS: Eleven fresh-frozen cadaver arms were dissected at the medial elbow. The CuTR was identified, and its thickness was measured. After excising the CuTR, we measured the elongation of the anterior and posterior aspects of the ulnar nerve, as well as the length of the CuTR origin/insertion, at increasing intervals of elbow flexion (15°, 30°, 45°, 90°, 120°, and 135°). Using 3-dimensional digitization technology, the surface of the cubital tunnel was recorded at 4 positions of elbow flexion (15°, 45°, 90°, and 135°) and analyzed to define the tunnel geometry. RESULTS: The CuTR origin-to-insertion length and the ulnar nerve length both increased significantly with increasing flexion angle. Both lengths at 90°, 120°, and 135° of elbow flexion were greater than at 15° or 30°. The cubital tunnel area was significantly less at 135° compared to either 45° or 90° of flexion. There was a linear relationship between the cubital tunnel area of the different arms with the corresponding nerve cross-sectional area when measured at the level of the epicondyle and when the arm was at 90° of elbow flexion. CONCLUSIONS: The CuTR begins to stretch at 60° of flexion and continues to stretch with increasing flexion. Similarly, the ulnar nerve is more taut in flexion. The area within the cubital tunnel decreases beyond 90° of elbow flexion. CLINICAL RELEVANCE: Understanding the dynamic anatomical relationships of the cubital tunnel might help in the safe treatment of cubital tunnel syndrome when using minimally invasive techniques and instrumentation.

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

OBJECTIVE: To 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). METHODS: In 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. RESULTS: We 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. CONCLUSION: Maximal 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. SIGNIFICANCE: The 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.

Origin of ulnar compound muscle action potential investigated in patients with ulnar neuropathy at the wrist.

The compound muscle action potential from the abductor digiti minimi muscle is bi-lobed, and its second peak is formed by far-field potentials (FFPs). We investigated their origin in two patients with ulnar neuropathy at the wrist that spared the hypothenar muscles. FFPs were lost or distorted, which indicated that the deep motor branch-innervated muscles, such as the interossei, mainly contributed to the FFPs, especially to their initial N1 and steep following P1 components.

Comparative study of surgical treatment of ulnar nerve compression at the elbow.

HYPOTHESIS: The optimal surgical treatment for cubital tunnel syndrome remains unclear. We aim to evaluate the long-term outcome of surgical treatment by comparing the results of the different methods proposed. MATERIALS AND METHODS: We retrospectively reviewed 113 patients in whom 3 different surgical methods were used for cubital tunnel syndrome treatment. In situ decompression, partial epicondylectomy, and anterior subcutaneous transposition were performed from 1997 to 2007. RESULTS: Results were graded as excellent in 51 patients (45%), good in 34 (30%), fair in 8 (7%), and poor in 20 (18%). When we compared the results among the different surgical procedures, good and excellent results were achieved in 26 of 31 patients (84%) treated with in situ decompression, 36 of 45 (80%) treated with release and partial medial epicondylectomy, and 23 of 37 (62%) treated with release and anterior subcutaneous transposition of the nerve. CONCLUSIONS: Our results indicate that in situ decompression and partial epicondylectomy both represent efficient and safe methods for cubital tunnel syndrome management. In patients in whom anterior subcutaneous transposition was performed, although they had a significant improvement of their clinical signs and symptoms, they had an inferior outcome when compared with patients treated with the other 2 methods.

[Ulnar entrapment neuropathy].

Ulnar nerve entrapment is one of the most common entrapment neuropathies in the upper limb. The most frequent location of this syndrome is behind the elbow. The clinical picture is associated with the localization of the entrapment but usually consists of an altered sensation at the fourth and fifth digits and a weakness of the intrinsic muscles of the palm. The most constructive tool in making the diagnosis and in assessing the treatment's efficacy is the physical examination. Treatment alternatives depend on entrapment location. Conservative treatment options such as rest, a change in the work environment and patterns as well as splints are all accepted modalities. A lack of improvement following conservative treatment or a deteriorating nerve function is an indication for surgical intervention. This includes procedures comprised of decompression of the ulnar nerve alone or those which combine its transposition.