Ultrasound of the Ulnar Nerve: A Pictorial Review: Part 1: Normal Ultrasound Findings.

This is the first of a two-part article in which we focus on the ultrasound (US) appearance of the normal ulnar nerve (UN) and its main branches. The detailed US anatomy of the UN course is presented with high-resolution US images obtained with the latest-generation US machines and transducers.

Ultrasound of the Ulnar Nerve: A Pictorial Review: Part 2: Pathological Ultrasound Findings.

This is the second part of a two-part article in which we focus on the ultrasound (US) appearance of the pathological ulnar nerve (UN) and its main branches. Findings in a wide range of our pathological cases are presented with high-resolution US images obtained with the latest-generation US machines and transducers.

Ultrasound-Based Multi-Planar Bilateral Comparisons as a Diagnostic and Treatment-Definition Method for Unilateral Peripheral Nerve Entrapment.

OBJECTIVE: The primary goal was to determine the performance of the cross-section area swelling rate (CSASR) for diagnostic and therapeutic purposes based on the reference standard of electrodiagnosis examination (EDX) in this diagnostic test study. METHODS: First, patients with symptoms like unilateral carpal tunnel syndrome (CTS), cubital tunnel syndrome (CuTS), and radial nerve compression (RNC) underwent EDX and ultrasound examination. Second, patients with positive ultrasound were calculated for the CSASR of diseased nerve. Based on previously established CSASR criteria, each patient was categorized as having or not having peripheral nerve entrapment, and for those meeting diagnostic criteria, non-surgical or surgical treatment was recommended. Then, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy rate (ACC) of ultrasound diagnosis and therapeutic decision-making were calculated based on the reference standard of EDX that had been historically used in the practice. RESULTS: The total sensitivity, specificity, PPV, NPV, and ACC of ultrasound diagnosis are respectively 93.4, 85.2, 94.7, 82.1, and 91.3%. Which of therapeutic decision-making by ultrasound are, respectively, 83.3, 52.2, 78.4, 60.0, and 73.2%. CONCLUSION: The sensitivity and Youden's index of CSASR diagnostic threshold for CuTS is higher than other ultrasound methods. The CSASR diagnostic threshold for CuTS has a potential diagnostic role, but the current date is still not enough to support the potential diagnostic role for CTS or RNS. There is insufficient evidence to suggest that CSASR for CuTS can be used in isolation for diagnosis. Additional research is needed to confirm the diagnostic role of CSASR. The current results suggest that this ultrasound examination method is not suitable for therapeutic decision-making.

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.

Cubital tunnel syndrome: anatomy, pathology, and imaging.

Cubital tunnel syndrome (CuTS) is the second most common peripheral neuropathy in the upper limb. It occurs due to ulnar nerve compression within the fibro-osseous cubital tunnel at the elbow joint. Although CuTS is typically diagnosed clinically and with electrodiagnostic studies, the importance of imaging in evaluating the condition is growing. Knowing the typical imaging findings of ulnar nerve entrapment is necessary for precise diagnosis and proper treatment. In this article, we focus on the clinical features, workup and complex imaging of the "anatomic" cubital tunnel and relevant pathological entities.

Revision surgery for recurrent ulnar nerve compression following failed subcutaneous transposition : Author list.

BACKGROUND: Recurrent ulnar nerve compression after primary anterior subcutaneous transposition is relatively rare, and revision surgery is challenging. This study retrospectively evaluated the clinical outcomes of revision anterior subcutaneous transposition for recurrent ulnar nerve compression. METHODS: Eight patients who underwent revision anterior subcutaneous transposition for recurrent ulnar nerve compression were enrolled in this study. The outcomes were based on preoperative and postoperative symptoms, physical examination findings, and electromyographic evaluation. RESULTS: Ulnar nerve enlargement was preoperatively found in all patients with a mean cross sectional area of 0.15 cm2 (range, 0.14-0.18 cm2). Intraoperative findings showed that recurrent compression occurred in three areas, including the medial intermuscular septum (n = 5), the medial epicondyle (n = 6) and nerve entrance to forearm fascia (n = 1). Post-operation, significant improvements were observed in ring/little finger numbness (from severe to mild, p = 0.031), grip strength (from 48.00% to 80.38% of the intact side, p < 0.001) and McGowan grade (from Grade III to Grade I, p = 0.049). Postoperative electromyography test also showed significant improvement in motor nerve conduction at elbow (velocity, 23.30 ± 9.598 vs. 35.30 ± 9.367, p = 0.012; amplitude, 3.40 ± 3.703 vs. 5.65 ± 2.056, p = 0.007) and sensory nerve conduction at wrist (velocity, 27.04 ± 22.450 vs. 36.45 ± 18.099, p = 0.139; amplitude, 1.44 ± 1.600 vs. 4.00 ± 2.642, p = 0.011). Seven of the eight patients reported satisfaction with the postoperative results. CONCLUSIONS: Revision anterior subcutaneous transposition was an effective treatment for recurrent ulnar nerve compression from prior failed procedures.

Direct Economic Burden of Cubital Tunnel Surgery in the United States: Total Payments and Components of Cost.

PURPOSE: Despite its widespread prevalence, the cost of cubital tunnel syndrome (CuTS) in the United States to patients and insurers is not well understood. The purpose of this study was to quantify the direct payments associated with operative treatment of CuTS. We hypothesized that CuTS represents a substantial cost to the payer in facility fees, surgeon fees and other expenses. METHODS: Utilizing the MarketScan database of insured patients (commercial and Medicaid), we identified a cohort of 41,777 patients aged 18-64 years with surgically treated CuTS from 2006 to 2018. We estimated the median 90-day payments from encounters associated with cubital tunnel release (CuTR) and/or ulnar nerve transposition surgery by summing all payments for claims within 90 days after the index surgery. Published estimates of the annual number of cubital tunnel surgeries were used to calculate the annual expenditure. RESULTS: Of 41,777 patients, the median (interquartile range [IQR]) values of total direct payments were $5,522 [$3,426, $9,541]. With an estimated 94,645 cases/year, this leads to an annual payment of more than $522 million. Index facility payments (median[IQR] $2,555 [$1,359, $4,708] were the highest, followed by index provider payments ($1,691 [$1,328, $2,217]). The median index surgeon payment (median[IQR] $905 [$707, $1,184]) represented just over half of the provider payments. Post-operative care had a median [IQR] payment of $377 ($424, $1,987). Limitations of claims databases prevented assessment of other indirect costs associated with cubital tunnel surgery. CONCLUSIONS: Payments for the surgical treatment of CuTS from the index surgery to 90 days post-operatively have an estimated median of $5,522 per patient, totaling $52 million annually. Index facility fees are responsible for more than 46% of payments, while index payments to surgeons represent approximately 16%. Defining this data is critical to understanding one component of the economic impact of CuTS. LEVEL OF EVIDENCE: Level IV.

On the Physiology of the Sensory-Collapse Test.

The sensory-collapse test (formerly the scratch-collapse test) is a physical examination finding describing a momentary inhibition of external shoulder rotation following light stimulation of an injured nerve in the ipsilateral limb. Similar to other physical examination tests designed to interrogate nerve compression, such as the Phalen or Tinel tests, its test characteristics demonstrate variation. There remains speculation about the test's existence and anatomic basis. The literature of mammalian reflex physiology was reviewed with an emphasis on the sensory pathways from the upper extremity, the extrapyramidal system, and newly discovered pathways and concepts of nociception. A clear reflex pathway is described connecting the stimulus within an injured nerve through the afferent pathways in the fasciculus cuneatus in the spinal cord directly to the lateral reticulospinal tract, resulting in the inhibition of extensor muscles in the proximal limb (eg, shoulder) and activation of the limb flexors by acting upon alpha and gamma motor neurons. The sensory-collapse test represents a reflex pathway that teleologically provides a mechanism to protect an injured nerve by withdrawal toward the trunk and away from the noxious environment.

Evaluation of Different Surgical Techniques for Revision Cubital Tunnel Release: A Meta-Analysis of Patient-Reported Symptoms.

PURPOSE: Controversy exists regarding the best option for revision surgery in refractory cubital tunnel syndrome (CuTS). The purpose of this systematic review was to evaluate the effectiveness of revision surgery and determine the optimal surgical approach for patients requiring revision surgery for CuTS. METHODS: A literature search was conducted. Characteristics of the included studies were summarized descriptively. The risk ratio between patient-reported preoperative and postoperative outcomes relating to pain, motor, and sensory deficits was calculated. A meta-regression analysis was performed to evaluate the postoperative symptom improvements based on the type of secondary surgery. Random-effects meta-analysis and descriptive statistics were used when appropriate. RESULTS: A total of 471 patients were evaluated in 20 studies. In total, 254 (53.9%) male and 217 (46.1%) female patients, with an average age of 49.2 ± 14.1 years, were included in this study. Pain was the most common symptom (n = 346, 81.6%), followed by sensory and motor dysfunction in 342 (80.6%) and 223 (52.6%) patients, respectively. Meta-analysis comparing preoperative and postoperative symptoms between patients who had submuscular transposition (SMT), subcutaneous transposition (SCT), and neurolysis showed that a significant subgroup difference exists between the types of revision surgery in sensory and motor improvements. Meta-regression showed that SMT was associated with better outcomes compared with SCT in motor and sensory improvements. CONCLUSIONS: Revision surgery for CuTS can be useful for addressing recurrent and persistent symptoms. Compared with neurolysis and SCT, SMT seems to be the superior option for revision surgery, demonstrating substantial improvement in all symptom domains. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Electrodiagnostic severity does not predict short- to midterm outcomes of cubital tunnel release surgery.

HYPOTHESIS: This study aimed to explore the prognostic value of electrodiagnostic studies (EDS) to clarify their utility in clinical practice prior to cubital tunnel release surgery and to identify patient factors associated with patient-reported functional improvement after surgery. Our hypothesis was that patients with severe preoperative findings on EDS will tend to experience less functional improvement after surgery given the extent of ulnar nerve compressive injury. METHODS: Patients with cubital tunnel syndrome and preoperative electrodiagnostic data treated from 2012 to 2022 with cubital tunnel release were assessed regarding demographic information, preoperative physical examination findings, EDS findings, postoperative complications, and patient-reported outcomes. Short- to midterm quick Disabilities of the Arm, Shoulder, and Hand questionnaire (qDASH) scores were collected for all patients for further evaluation of preoperative EDS data. Patients were grouped into those who had met the minimal clinically important difference (MCID) in delta qDASH at short- to midterm follow-up and those who did not. EDS data included sensory nerve onset latency, peak latency, amplitude, conduction velocity, as well as motor nerve latency, velocity, and amplitude. Electromyographic (EMG) studies were also reviewed, which included data pertaining to fibrillations, presence of abnormal fasciculation, positive sharp waves, variation in insertional activity, motor unit activity, duration of activity, and presence of increasing polymorphisms. RESULTS: Of the 257 patients included, 160 (62.0%) were found to meet the MCID for short- to midterm qDASH scores. There were no significant differences between patients who did or did not meet the MCID regarding baseline demographics, comorbidities, preoperative examination findings, and operative technique. Patients who met MCID tended to have lower complication (3.80% vs. 7.20%, P = .248) and revision (0.60% vs. 4.10%, P = .069) rates, but these findings were not statistically significant. The cubital tunnel severity as determined by the EDS was similar between cohorts (14.1% vs. 14.3%, P = .498). Analysis of EMG testing showed there were no significant differences in preoperative, short- to midterm qDASH, or delta short- to midterm qDASH scores for patients with or without abnormal EMG findings. Multivariate regression suggested that only age (P = .003) was associated with larger delta qDASH scores. CONCLUSION: Patient-reported preoperative disease severity may predict the expected postoperative change in ulnar nerve functional improvement, and EDS may not have prognostic value for patients undergoing cubital tunnel decompression. Therefore, physicians may suggest surgical treatment without positive EDS findings and still expect postoperative improvement in functional outcomes.

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

HYPOTHESIS: The purpose of this study was to compare inter- and intraobserver agreement of a novel intraoperative subluxation classification for patients undergoing ulnar nerve surgery at the elbow. We hypothesize there will be strong inter- and intraobserver agreement of the 4-category classification system, and reviewers will have substantial confidence while reviewing the classification system. METHODS: Four blinded fellowship-trained orthopedic hand surgeons reviewed 25 videos in total on 2 separate viewings, 21 days apart. Variables collected were ulnar subluxation classification (A, B, C, or D) and a confidence metric. Subsequent to primary data collection, classification grading was stratified into A/B or C/D subgroups for further analysis. Cohen κ scores were used to evaluate all variables collected in this study. The interpretation of κ scores included ≤0.0 as no agreement, 0.01-0.20 as none to slight, 0.21-0.40 as fair, 0.41-0.60 as moderate, 0.61-0.80 as substantial, and 0.81-1.0 as almost perfect agreement. RESULTS: Interobserver agreement of subluxation classification as a 4-category scale demonstrated a moderate agreement on first viewing, second viewing, and when both viewings were combined (κ = 0.51, 0.51, and 0.51 respectively). Seventy-five percent (3 of 4) of reviewers had moderate intraobserver agreement for ulnar nerve subluxation classification, whereas 1 reviewer had substantial intraobserver classification (κ = 0.72). Overall, there was high confidence in 65% of classification scores in the second round of viewing, which improved from 58% in the first viewing round. When ulnar subluxation classification selections were regrouped into classes A/B or C/D, 100% of reviewers had substantial interobserver (κ = 0.74-0.75) and substantial to almost perfect intraobserver (κ = 0.71-0.91) agreement. CONCLUSIONS: The 4-category classification was reproducible within and between reviewers. Agreement appeared to increase when simplifying the classification to 2 categories, which may provide guidance to surgical decision making. The validation of a reproducible classification scheme for intraoperative ulnar subluxation may aid with decision making and further postoperative outcomes research.

Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers.

BACKGROUND: Radiographic and physical examination findings of ulnar nerve instability have been recognized in overhead throwing athletes, despite the fact that some of these abnormalities may be asymptomatic and represent adaptive changes. While recommendations for screening and early detection have been made that can adversely impact an athletes' career, the presence of bilateral ulnar nerve subluxation and its relationship with medial elbow symptoms has not been characterized in professional overhead throwing athletes. PURPOSE: To characterize the prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers. METHODS: A cross-sectional observational analysis was conducted utilizing standardized ultrasonographic examinations of bilateral elbows in 91 consecutive professional baseball pitchers (median age, 22 years; range, 17-30 years). The relationship between ulnar nerve subluxation and ulnar nerve signs, symptoms, and provocative physical examination maneuvers was also investigated. RESULTS: The prevalence of bilateral ulnar nerve subluxation was 26.4% (95% CI, 17.7%-36.7%; 24 of the 91 athletes). Thirty-five athletes (38.5%; 95% CI, 28.4%-49.2%) had subluxation in at least 1 elbow. No athletes with subluxation had positive ulnar nerve signs, symptoms, or provocative tests. CONCLUSION: Ulnar nerve subluxation is common among professional pitchers, and is more often than not bilateral. In this population of athletes, ulnar nerve subluxation does not appear to be associated with pathological findings.

Effectiveness of chitosan phonophoresis on ulnar nerve conduction velocity, pain relief, and functional outcomes for mild to moderate cubital tunnel syndrome: A double-blind randomized controlled trial.

BACKGROUND: Cubital tunnel syndrome (CBTS) impairs hand function, with limited conservative options often leading to surgery. Chitosan neuroregenerative effects delivered via phonophoresis provide a rationale for testing this emerging treatment approach. PURPOSE: The primary goal of this research was to assess the impact of chitosan phonophoresis on the conductivity of the ulnar nerve, as well as its effects on pain levels and functional outcomes in individuals diagnosed with mild to moderate CBTS. STUDY DESIGN: Double-blind randomized controlled trial. METHODS: This was a prospective, double-blinded, randomized controlled study. The participants consisted of 54 individuals aged between 20-35 years who were randomly assigned using block randomization. The control group (n = 27) received standard hand therapy alone, while the experimental group (n = 27) received both standard hand therapy and chitosan phonophoresis. Both groups underwent three treatment sessions per week, each lasting for 60-72 minutes, over a period of five weeks. Pre- and post-intervention evaluations included assessments of ulnar nerve conduction velocity (NCV), pain assessment using the numerical pain rating scale (NPRS), as well as hand function evaluated using the Quick Disabilities of Arm Shoulder Hand (QuickDASH) questionnaire. RESULTS: After the intervention, the experimental group significantly improved in all outcome measures compared to the control group. Accordingly, ulnar NCV (MD = 2.233 m/sec; CI = 1.63:2.83; p < 0.001; η2p = 0.516), NPRS (MD = -1.11; CI = -1.71: -0.50; p < 0.001; η2p = 0.208) and QuickDASH (MD = -2.72; CI = -4.54:0.87; p < 0.007; η2p = 0.133). CONCLUSIONS: The study findings suggest that chitosan phonophoresis may have the potential as a supplementary treatment to hand therapy for individuals with mild to moderate CBTS. This approach demonstrated significant improvements in nerve conduction, pain reduction, and enhancement of hand function.

The anatomical variations of the cubital tunnel in a South African body donor sample.

PURPOSE: The ulnar nerve (UN) courses through the cubital tunnel, which is a potential site of entrapment. Anatomical variations of the cubital tunnel may contribute towards cubital tunnel syndrome (CuTS), however, these are not well described. The aim was to compare the range of variations and dimensions of the cubital tunnel and the UN between sexes and sides of the body. METHODS: Sixty elbows from 30 embalmed bodies (17 males and 13 females) were dissected. The prevalence of the cubital tunnel retinaculum (CuTR) or anconeus epitrochlearis (AE) forming the roof of the tunnel was determined. The length, width, thickness, and diameter of the cubital tunnel and its roof were measured. The diameter of the UN was measured. RESULTS: The AE was present in 5%, whereas the CuTR was present in the remaining 95% of elbows. The tunnel was 32.1 ± 4.8 mm long, 23.4 ± 14.2 mm wide, 0.18 ± (0.22-0.14) mm thick, and the median diameter was 7.9 ± (9.0-7.1) mm, while the median diameter of the UN was 1.6 ± (1.8-1.3) mm. The AE was thicker than the CuTR (p < 0.001) and the UN was larger in elbows with the AE present (p = 0.002). The tunnel was longer in males (p < 0.001) and wider on the right (p = 0.014). CONCLUSION: The roof of the cubital tunnel was more frequently composed of the CuTR. The cubital tunnel varied in size between sexes and sides. Future research should investigate the effect of the variations in patients with CuTS.

Ulnar neuropathy at the elbow: associations of pre-operative DTI parameters with clinical outcomes after cubital tunnel decompression.

OBJECTIVES: To evaluate whether DTI parameters of the ulnar nerve at the elbow are associated with clinical outcomes in patients receiving cubital tunnel decompression (CTD) surgery for ulnar neuropathy. METHODS: This retrospective study included 21 patients with cubital tunnel syndrome who received CTD surgery between January 2019 and November 2020. All patients underwent pre-operative elbow MRI, including DTI. Region-of-interest analysis was performed on the ulnar nerve at three levels around the elbow: above (level 1), cubital tunnel (level 2), and below (level 3). Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were calculated on three sections at each level. Clinical data on symptom improvement in respect to pain and tingling sensation after CTD were recorded. Logistic regression analysis was used to compare DTI parameters of the nerve at three levels and the entire nerve course between patients with and without symptom improvement after CTD. RESULTS: After CTD, 16 patients showed improvement in symptoms, but five did not. ROC analysis of DTI parameters showed that AUCs of FA, AD, and MD were higher at level 1 than at levels 2 and 3, with FA showing the highest AUC (level 1: FA, 0.7104 [95% CI, 0.5206-0.9002] vs AD, 0.6521 [95% CI, 0.4900-0.8142] vs MD, 0.6153 [95% CI, 0.4187-0.8119]). CONCLUSION: In patients who underwent CTD surgery for ulnar neuropathy at the elbow, the DTI parameters of FA, AD, and MD above the cubital tunnel level were associated with clinical outcomes, with FA showing the strongest associations. KEY POINTS: • After CTD surgery for ulnar neuropathy at the elbow, persistent symptoms may be observed, depending on symptom severity. • DTI parameters of the ulnar nerve at the elbow showed differences in their capacity for discriminating between patients with and without symptom improvement following CTD surgery, with this capacity depending on the nerve level at the elbow. • FA, AD, and MD measured above the cubital tunnel on pre-operative DTI may be associated with surgical outcomes, with FA showing the strongest association (AUC at level 1, 0.7104 [95% CI, 0.5206-0.9002]).

Protocol for Endoscopic Versus Open Cubital tunnel release (EVOCU): an open randomized controlled trial : EVOCU trial: Endoscopic Versus Open Cubital tunnel release.

BACKGROUND: Cubital tunnel syndrome is the second most common entrapment neuropathy of the upper extremity. Surgical decompression of the ulnar nerve aims to improve complaints and prevent permanent damage to the nerve. Open and endoscopic release of the cubital tunnel are both used in common practice, but none has proven to be superior. This study assesses patient reported outcome and experience measures (PROMs and PREMs respectively), in addition to objective outcomes of both techniques. METHODS: A prospective single-center open randomized non-inferiority trial will take place at the Plastic Surgery Department in the Jeroen Bosch Hospital, the Netherlands. 160 patients with cubital tunnel syndrome will be included. Patients are allocated to endoscopic or open cubital tunnel release by randomization. The surgeon and patients are not blinded for treatment allocation. The follow-up time will take 18 months. DISCUSSION: Currently, the choice for one of the methods is based on surgeon's preferences and degree of familiarity with a particular technique. It is assumed that the open technique is easier, faster and cheaper. The endoscopic release, however, has better exposure of the nerve and reduces the chance of damaging the nerve and might decrease scar discomfort. PROMs and PREMs have proven potential to improve the quality of care. Better health care experiences are associated with better clinical outcome in self-reported post-surgical questionnaires. Combining subjective measures with objective outcomes, efficacy, patient treatment experience and safety profile could help differentiating between open and endoscopic cubital tunnel release. This could aid clinicians in evidence based choices towards the best surgical approach in patients with cubital tunnel syndrome. TRIAL REGISTRATION: This study is registered prospectively with the Dutch Trial Registration under NL9556. Universal Trial Number (WHO-UTN) U1111-1267-3059. Registration date 26-06-2021. The URL: https://www.trialregister.nl/trial/9556.

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.

Cubital Tunnel Syndrome: Does a Consensus Exist for Diagnosis?

PURPOSE: Cubital tunnel syndrome (CuTS) is the second most common compressive neuropathy of the upper extremity. We aimed to determine a consensus among experts using the Delphi method for clinical criteria that could be validated further for the diagnosis of CuTS. METHODS: The Delphi method was used for establishing a consensus among a group of expert panelists, comprising 12 hand and upper-extremity surgeons, who ranked the diagnostic clinical importance of 55 items related to CuTS on a scale from 1 (least important) to 10 (most important). The average and SDs of each item were calculated, and Cronbach α was used to assess homogeneity among the panelist-ranked items. RESULTS: All panelists answered the 55-item questionnaire. A Cronbach α value of 0.963 was obtained on the first iteration. The top criteria that were considered most clinically relevant to the diagnosis of CuTS among the group were determined based on the most highly ranked and correlated items among the expert panelist group. The criteria based on which there was agreement were as follows: (1) paresthesias in ulnar nerve distribution, (2) symptoms precipitated by increased elbow flexion/positive elbow flexion tests, (3) positive Tinel sign at the medial elbow, (4) atrophy/weakness/ late findings (eg, claw hand of the ring/small finger and Wartenberg or Froment sign) of ulnar nerve-innervated muscles of the hand, (5) loss of two-point discrimination in ulnar nerve distribution, and (6) similar symptoms on the involved side after successful treatment on the contralateral side. CONCLUSIONS: Our study demonstrated a consensus among an expert panelist group of hand and upper-extremity surgeons on potential diagnostic criteria for CuTS. This consensus on diagnostic criteria may help clinicians readily diagnose CuTS in a standardized form; however, further weighting and validation are necessary prior to the development of a formal diagnostic scale. CLINICAL RELEVANCE: This study is the first step in producing a consensus on how to diagnose CuTS.

The Responsiveness of the Patient-Reported Outcomes Measurement Information System Upper Extremity and Physical Function in Patients With Cubital Tunnel Syndrome.

PURPOSE: The Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE) and PROMIS Physical Function (PF) are increasingly referenced patient-reported outcomes. To interpret treatment effects with these patient-reported outcomes, investigators must understand magnitudes of change that represent clinically relevant improvement. This study assessed the responsiveness of PROMIS UE and PF in patients with cubital tunnel syndrome. METHODS: A retrospective analysis of PROMIS UE and PROMIS PF computer adaptive test scores was performed for patients treated nonoperatively for cubital tunnel syndrome over 3 years at a tertiary institution. The Patient-Reported Outcomes Measurement Information System UE and PROMIS PF outcome scores were collected at initial and return clinic visits. At follow-up appointments, patients completed clinical anchor questions evaluating their degree of interval clinical improvement. Anchor questions allowed categorization of patients into groups that had experienced "no change," "minimal change," and "much change." Minimal clinically important difference (MCID) values were calculated for the PROMIS assessments with anchor-based and distribution-based methods. RESULTS: A total of 304 patients with PROMIS PF scores and 111 with PROMIS UE scores were analyzed. The MCID for the PROMIS UE was 3.1 (95% confidence interval, 1.4-4.8) using the anchor-based method and 3.7 (95% confidence interval, 2.9-4.4) using the distribution-based method. These point estimates exceeded the minimal detectable change of 2.3. The MCID for the PROMIS PF was unable to be determined in this patient sample because patients reporting mild change did not have score changes exceeding measurement error. CONCLUSIONS: The PROMIS UE v2.0 computer adaptive test detected minimal change in patients managed nonoperatively for cubital tunnel syndrome with an estimated MCID range of 3.1-3.7. While PROMIS PF has demonstrated acceptable performance in patients with a variety of upper extremity conditions, for cubital tunnel syndrome, it was less able to detect subtle change. PROMIS UE appears more responsive to subtle changes in cubital tunnel syndrome symptoms. CLINICAL RELEVANCE: Patient-reported outcomes may have varied responsiveness depending on the condition studied.

Identifying Risk Factors for Recurrence After Cubital Tunnel Release.

PURPOSE: This study investigated specific risk factors for recurrent surgery of ulnar nerve entrapment (ie, ipsilateral clinical symptoms within 5 years after initial cubital tunnel release [CuTR]) in a large cohort. We hypothesized that recurrence is associated with lifestyle variables (eg, smoking, drinking alcohol, a high body mass index [BMI]) or comorbidities). METHODS: A retrospective cohort study was performed using the Current Procedural Terminology codes for all patients who underwent CuTR between January 2012 and November 2018. Demographic data, including sex, age, weight, height, BMI, comorbidities, smoking, and alcohol consumption, were collected. The primary outcome was the need for revision surgery after initial CuTR. Univariate and multivariate analyses were performed to identify potential risk factors for revision surgery. RESULTS: Of the 678 patients who underwent CuTR, 120 patients (18%) needed revision surgery within 5 years. Sixty-six patients required subfascial transposition (55%) and 47 patients (39%) received in situ releases. Also, sex, BMI, smoking, alcohol consumption, and comorbidities (except for spinal disc herniation) were similar between the primary and revision subgroup. Age at first occurrence was significantly lower in the revision group (48 years for revision vs 52 years for primary surgery). Moreover, cervical spinal disc herniation was associated with revision surgery (13% vs 6% in the primary group). CONCLUSIONS: Age and medical history of cervical spinal disc herniation are associated with an increased risk of revision surgery. More importantly, BMI, smoking, alcohol consumption, and other comorbidities are not associated with increased risk of revision surgery within our sample. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.