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.

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.

Cubital tunnel release with Wide Awake Local Anaesthesia No Tourniquet (WALANT) technique in an outpatient setting is safe and effective.

Ulnar nerve release is often performed under general anaesthesia. Wide Awake Local Anaesthesia No Tourniquet (WALANT) is a new anaesthetic method increasingly used by hand surgeons in an outpatient setting. It has advantages such as the possibility to shift surgical interventions out of the regular surgical theatre settings into an outpatient clinical setting, no risk of complications or side effects resulting from regional and general anesthesia and decreased costs. The use of WALANT has not been investigated extensively in elbow surgery. This study aims to evaluate clinical outcomes after ulnar nerve release under WALANT 27 patients with ulnar nerve release for cubital tunnel syndrome were included. The primary outcome was the presence of (remaining) symptoms after ulnar nerve release. Data was extracted from medical records. 13 out of 27 patients had (mild) remaining symptoms after ulnar nerve release, and 1 complication (superficial wound infection) was seen. Ulnar nerve release under WALANT is safe and effective in patients with primary ulnar nerve entrapment that have failed conservative therapy.

What Factors Are Associated With Revision Cubital Tunnel Release Within 3 Years?

BACKGROUND: It has been shown that patient demographics such as age, payer factors such as insurance type, clinical characteristics such as preoperative opioid use, and disease grade but not surgical procedure are associated with revision surgery to treat cubital tunnel syndrome. However, prior studies evaluating factors associated with revision surgery after primary cubital tunnel release have been relatively small and have involved patients from a single institution or included only a single payer. QUESTIONS/PURPOSES: (1) What percentage of patients who underwent cubital tunnel release underwent revision within 3 years? (2) What factors are associated with revision cubital tunnel release within 3 years of primary cubital tunnel release? METHODS: We identified all adult patients who underwent primary cubital tunnel release from January 1, 2011, to December 31, 2017, in the New York Statewide Planning and Research Cooperative System database using Current Procedural Terminology codes. We chose this database because it includes all payers and nearly all facilities in a large geographic area where cubital tunnel release may be performed. We used Current Procedural Terminology modifier codes to determine the laterality of primary and revision procedures. The mean age of the cohort overall was 53 ± 14 years, 43% (8490 of 19,683) were women, and 73% (14,308 of 19,683) were non-Hispanic White. The Statewide Planning and Research Cooperative System database organization does not include a listing of all state residents and thus does not allow for censoring of patients who move out of state. All patients were followed for 3 years. We developed a multivariable hierarchical logistic regression model to model factors independently associated with revision cubital tunnel release within 3 years. Key explanatory variables included age, gender, race or ethnicity, insurance, patient residential location, medical comorbidities, concomitant procedures, whether the procedure was unilateral or bilateral, and year. The model also controlled for facility-level random effects to account for the clustering of observations among these entities. RESULTS: The risk of revision cubital tunnel release within 3 years of the primary procedure was 0.7% (141 of 19,683). The median time to revision cubital tunnel release was 448 days (interquartile range 210 to 861 days). After controlling for patient-level covariates and facility random effects, and compared with their respective counterparts, the odds of revision surgery were higher for patients with workers compensation insurance (odds ratio 2.14 [95% confidence interval 1.38 to 3.32]; p < 0.001), a simultaneous bilateral index procedure (OR 12.26 [95% CI 5.93 to 25.32]; p < 0.001), and those who underwent submuscular transposition of the ulnar nerve (OR 2.82 [95% CI 1.35 to 5.89]; p = 0.006). The odds of revision surgery were lower with increasing age (OR 0.79 per 10 years [95% CI 0.69 to 0.91]; p < 0.001) and a concomitant carpal tunnel release (OR 0.66 [95% CI 0.44 to 0.98]; p = 0.04). CONCLUSION: The risk of revision cubital tunnel release was low. Surgeons should be cautious when performing simultaneous bilateral cubital tunnel release and when performing submuscular transposition in the setting of primary cubital tunnel release. Patients with workers compensation insurance should be informed they are at increased odds for undergoing subsequent revision cubital tunnel release within 3 years. Future work may seek to better understand whether these same effects are seen in other populations. Future work might also evaluate how these and other factors such as disease severity could affect functional outcomes and the trajectory of recovery. LEVEL OF EVIDENCE: Level III, therapeutic study.

A 10-Year Update of Outcome Measures Used to Assess Results After Surgery for Cubital Tunnel Syndrome: A Systematic Review of the Literature.

HYPOTHESIS: Outcomes reporting for the surgical release of ulnar nerve cubital tunnel entrapment have variability in subjective, objective, and validated measures. The aim of this study is to review the literature to reassess the measures used to report surgical outcomes for ulnar neurolysis at the elbow. METHODS: This study was conducted in accordance with the PRISMA guidelines on systematic reviews. Six electronic databases were queried from the past 10 years using specific search terms and Boolean operators. Two independent reviewers assessed 4290 unique titles and abstracts that were screened for inclusion criteria. Sixty-eight full text articles were included for analysis. RESULTS: Statistical significance was noted in the number of outcome measures reported between studies from journals of impact factor within the first and third quartiles (P = 0.0086) and first and fourth quartiles (P = 0.0247), although no significance exists in the number of cubital tunnel-specific measures based on impact factor (P = 0.0783). Seventy-nine percent (n = 54) of the included studies report subjective measures; 54% (n = 37) included objective measures. Seventy percent (n = 48) of the studies report disease-specific outcome measures. CONCLUSION: There exists a discordance within the literature regarding the most appropriate, descriptive, and translational measures for reporting surgical outcomes of cubital tunnel syndrome. We recommend journal editors implement a requirement that authors reporting outcomes of ulnar nerve decompression must use a standard, validated measure to make comparisons across the literature universal. Furthermore, a minimum of at least 1 subjective and 1 objective measure should be standard.

Endoscopic Versus Open Carpal Tunnel Surgery: Risk Factors and Rates of Revision Surgery.

PURPOSE: The purpose of our study was to compare the 1-year revision surgery rates and outcomes of open versus endoscopic carpal tunnel release. Our hypothesis was that, compared to open release, endoscopic carpal tunnel release was an independent risk factor for revision surgery within 1-year. METHODS: This was a retrospective cohort study of 4338 patients undergoing isolated endoscopic or open carpal tunnel release. Demographic data, medical comorbidities, surgical approach, need for revision surgery, hand dominance, history of prior injection, and Patient Reported Outcomes Measurement Information System upper extremity (UE), pain interference (PI) and physical function scores were analyzed. Multivariable analysis was used to identify the risk factors for revision surgery within one year of the index procedure. RESULTS: In total, 3280 patients (76%) underwent open and 1058 (24%) underwent endoscopic carpal tunnel release. Within one year of the index procedure, 45 patients required revision carpal tunnel release. The average time to revision was 143 days. The rate of revision carpal tunnel release in the open group was 0.71% compared to 2.08% in the endoscopic group. Multivariable analysis demonstrated that endoscopic surgery, male sex, cubital tunnel syndrome, tobacco use, and diabetes were associated independently with revision surgery. CONCLUSIONS: In this study, we found that endoscopic carpal tunnel release was associated independently with a 2.96 times greater likelihood of requiring revision carpal tunnel release within one year, compared to open carpal tunnel release. Male sex, concurrent cubital tunnel syndrome, tobacco use, and diabetes also were associated independently with greater risk of needing revision carpal tunnel release within one year. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Wound Dehiscence Following Cubital Tunnel Surgery.

PURPOSE: Cubital tunnel syndrome is the second most common upper-extremity compressive neuropathy, and persistent symptoms can necessitate operative treatment. Surgical options include simple decompression and ulnar nerve transposition. The cause of wound dehiscence after surgery is not well known, and the factors leading to the development of these complications have not been previously described. METHODS: Patients undergoing ulnar nerve surgery from January 1, 2016, to December 31, 2019, were retrospectively evaluated for the development of wound dehiscence within 3 months of surgery. There were 295 patients identified who underwent transposition and 1,106 patients who underwent simple decompression. Patient demographics and past medical history were collected to evaluate the risk factors for the development of wound dehiscence. RESULTS: The overall rate of wound dehiscence following surgery was 2.5%. In the simple decompression group, the rate of wound dehiscence was 2.7% (30/1,106), which occurred a mean of 21 days (range, 2-57 days) following surgery. In the transposition group, the rate of wound dehiscence was 1.7% (5/295), which occurred a mean of 20 days (range, 12-32 days) following surgery. The difference in rates of dehiscence between the decompression and transposition groups was not significant. Five patients in the simple decompression group and 1 patient in the transposition group required a secondary surgery for closure of the wound. Age, body mass index, smoking status, and medical comorbidities were not found to contribute to the development of wound dehiscence. CONCLUSIONS: Wound dehiscence can occur following both simple decompression and transposition, even after postoperative evaluation demonstrates a healed wound. Surgeons should be aware of this possibility and specifically counsel patients about remaining cautious with, and protective of, their wound for several weeks after surgery. Dehiscence may be related to suboptimal vascularity in the soft tissue envelope in the posteromedial elbow. When it occurs, dehiscence can generally be treated by allowing healing by secondary intention. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

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.

A complete analysis of the surgical treatment for cubital tunnel syndrome: an umbrella review.

BACKGROUND: Numerous original studies have been presented regarding various surgical treatments for cubital tunnel syndrome (CubTS). The results of these analyses regarding the different surgical treatments for CubTS frequently differ and, in some cases, contradict each other, creating confusion. Therefore, our umbrella review aimed to summarize the evidence from meta-analyses and systematic reviews regarding the surgical treatments of CubTS, and along with the new, more detailed outcomes, provide an evidence-based tool for surgeons performing these procedures. MATERIALS AND METHODS: To perform this umbrella review, a systematic search was conducted for meta-analyses investigating CubTS in PubMed, Scopus, Embase, Web of Science, Google Scholar, Cochrane Library, BIOSIS, and EBSCO medical databases. RESULTS: Detailed comparison of surgical outcomes, such as clinical improvement, complications, or reoperation rates, of different treatment methods for CubTS was performed. New risk ratios in all categories were established based on all of the primary studies available in the literature. DISCUSSION: The goal of the present umbrella review was to gather and summarize all data about the surgical treatments for CubTS in the available literature and provide new outcomes and an evidence-based tool for surgeons performing these procedures. Each comparison of the surgical techniques has been discussed, and the present study's results were compared with the outcomes of the previous studies.

Ulnar Groove Plasty Guided by a 3D Printing Technique for Moderate to Severe Cubital Tunnel Syndrome Caused by Elbow Osteoarthritis.

BACKGROUND The purpose of this study was to explore the feasibility of ulnar groove plasty guided by a three-dimensional (3D) printing technique for treatment of moderate to severe cubital tunnel syndrome (CuTS) caused by elbow osteoarthritis. MATERIAL AND METHODS Patients with moderate to severe CuTS secondary to osteoarthritis of the elbow were enrolled in our hospital from April 2015 to March 2018. Based on a previously proposed "elbow canal index", a 1: 1 model of the elbow joint was printed using CT image data collected preoperatively. After computer-aided measurement, the standard for enlargement of the ulnar nerve groove was calculated and a personalized "trial model" was created by 3D reconstruction. After intraoperative exposure of the ulnar nerve sulcus, the proliferative osteoid was burred with a grinding drill, and the cubital enlargement was verified by the trial model. The ulnar nerve was decompressed and reincorporated into the enlarged cubital canal, and the Osborne ligament was zig-zag elongated and reconstructed. RESULTS None of the patients reported experiencing medial elbow instability, medial elbow pain, ulnar nerve subluxation, flexor-pronator weakness, or incision infection. There was significant improvement of the motor nerve conduction velocity, sensory nerve conduction velocity, two-point discrimination of the little finger, grip strength, pinch strength of the thumb and index finger, VAS score, and DASH score in this study (P<0.001). CONCLUSIONS Ulnar groove plasty guided by a 3D printing technique may be another effective treatment of moderate to severe CuTS caused by elbow osteoarthritis.

Research reporting in cubital tunnel syndrome studies: an analysis of the literature.

PURPOSE: There is a strong need for a set of consensus outcomes to be utilized for future studies on cubital tunnel syndrome. The goal was to assess the outcome measures utilized in the cubital tunnel syndrome literature as a way of measuring popularity/acceptability and then to perform a literature review for the most commonly used outcomes. METHODS: A literature search was performed using the pubmed.gov database and Medical Subject Headings (MeSH). For each article, the following data were abstracted: study type, motor outcome(s), sensory outcome(s), composite outcome(s), patient-reported outcome (PRO) metric(s), pain outcome(s), psychological outcome(s), electrodiagnostic outcome(s), and any other outcomes that were used. RESULTS: A composite outcome was reported in 52/85 (61%) studies, with the modified Bishop score (27/85; 32%) most common. A motor outcome was reported in 44/85 (52%) studies, with dynamometry (38/85; 45%) most common. The majority of studies (55%) did not report a sensory outcome. The majority of studies (52%) did not report a PRO. A specific pain outcome was reported in the minority (23/85; 27%), with the visual analogue scale (VAS) (22/85; 26%) most common. Pre- and postoperative electrodiagnostic results were presented in 22/85 studies (26%). DISCUSSION: Understanding current clinical practice and historical outcomes reporting provides a foundation for discussion regarding the development of a core outcome set for cubital tunnel syndrome. We hope that the data provided in the current study will stoke a discussion that will culminate in a consensus statement for research reporting in cubital tunnel syndrome studies.

Does Complexity Always Correlate With Compensation? An Analysis of Work Relative Value Units in 3 Common Nerve Decompression Syndromes.

BACKGROUND: Work relative value units (wRVUs) are part of Resource Based Relative Value Scale system. It is expected that a more difficult and time-consuming procedure would yield higher wRVUs. Brachial plexus nerve decompression surgery is a more time-consuming procedure compared with carpal and cubital tunnel procedures. The aim of this study was to analyze physician reimbursement in upper limb decompression procedures by comparing mean operative times, wRVUs per minute, and dollars per minute. METHODS: A retrospective cohort study was conducted from June 2016 to June 2019, including all patients who underwent carpal tunnel, cubital tunnel, and brachial plexus release procedures. Operating time was collected, and calculations of mean operative time, wRVUs per minute, and dollars per minute were performed and compared between groups. RESULTS: A total of 209 cases were included. Carpal tunnel accounted for 75.1% of the cases, followed by cubital tunnel and brachial plexus releases. Brachial plexus release had the highest median operative time (147 minutes), followed by cubital tunnel (57 minutes) and carpal tunnel release (16 minutes, P < 0.0001). Carpal tunnel release procedures had a significantly higher wRVUs per minute (0.310) when compared with cubital tunnel and brachial pleaxus release procedures, 0.127 and 0.077, respectively (P < 0.0001). Same was true for dollars per minute; carpal tunnel procedures yielded significantly more compensation than cubital tunnel and thoracic outlet procedures (P < 0.0001). CONCLUSIONS: More complex and time-consuming procedures yielded a lower reimbursement for physicians. The current work relative unit system does not account adequately for the time spent in each procedure.

A Comparison of Nerve-Specific, Condition-Specific, and Upper Extremity-Specific Patient-Reported Outcome Measures in Patients With Carpal and Cubital Tunnel Syndrome.

PURPOSE: Arm-, region-, tissue-, and condition-specific patient-reported outcome measures (PROMs) are available to address idiopathic mononeuropathy. This study compared PROMs with varying specificities in patients with idiopathic neuropathy of the upper extremity with respect to correlations with each another, sources of variation in scores, and floor and ceiling effects. METHODS: One hundred fifty patients (130 with carpal tunnel syndrome, 30 with cubital tunnel syndrome, and 10 with both conditions) completed a nerve-specific PROM (Impact of Hand Nerve Disorders), a condition-specific PROM (Boston Carpal Tunnel Syndrome Questionnaire and/or Patient-Rated Ulnar Nerve Evaluation), and an upper extremity-specific PROM (Patient-Reported Outcomes Measurement Information System Physical Function Upper Extremity 7). We also gathered demographic and condition-related data (side, electrodiagnostic studies present, muscle atrophy, static loss of sensibility), and patients completed questionnaires measuring self-efficacy, kinesiophobia, and symptoms of depression. Correlation of the PROMs with each another and factors accounting for their variation were assessed, as well as the number of items to complete, time to complete, and floor and ceiling effects. RESULTS: Pearson correlations between PROMs were moderate to strong (0.56-0.90). Self-reported symptoms of depression were best able to account for the variations in symptom intensity and activity intolerance on all PROMs (adjusted R2 between 0.09 and 0.31). The Impact of Hand Nerve Disorders is a long questionnaire and took the most time to complete. All instruments had comparable floor effects; Patient-Reported Outcomes Measurement Information System Physical Function Upper Extremity had a ceiling of effect of 16%. CONCLUSIONS: This study adds to the evidence that specific and general PROMs correlate with each another, perhaps in part through their correlation with mental health. Based on this line of evidence and pending testing of potentially greater responsiveness in specific settings, we prefer to use a single simple, brief, and general PROM to quantify symptom intensity and activity intolerance for both routine patient care and research. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Wide Awake Local Anesthesia No Tourniquet Endoscopic Cubital Tunnel Release.

As demands for faster return to function, improvement in surgical scarring, and minimal disruption to personal schedule have increased, so also have the demands increased for minimally invasive procedures under the wide awake, local anesthetic, no tourniquet method. However, owing to the subcutaneous yet constrained position of the ulnar nerve at the elbow, wide-awake endoscopic cubital tunnel release has remained a technical challenge. We describe a 2-stage local anesthetic injection method that safely introduces local anesthetic within the cubital tunnel and simultaneously achieves comfort, sufficient visualization, and the ability to decompress multiple compression sites through a minimal incision.

Outcome of Simple Decompression of Primary Cubital Tunnel Syndrome Based on Patient-Reported Outcome Measurements.

PURPOSE: To evaluate the patient-reported outcome measures of patients with primary cubital tunnel syndrome and to assess whether they are affected by preoperative symptom severity. METHODS: Patients who underwent simple decompression for primary cubital tunnel syndrome were selected from a prospectively maintained database. Outcome measurements consisted of the Boston Carpal Tunnel Questionnaire at intake and at 3 and 6 months after surgery. Also, 6 months after surgery, the patients received a question about their satisfaction with the treatment result. To determine a possible influence of preoperative symptom severity on postoperative outcomes, the sample was divided into quartiles based on symptom severity at intake. RESULTS: One hundred and forty-five patients were included in the final analysis. On average, all patients improved on the Boston Carpal Tunnel Questionnaire. The subgroup of patients with the mildest symptoms at intake did not improve significantly on symptom severity but did improve significantly on their functional status. In addition, the patients with the most severe symptoms at intake did improve on both aspects. Moreover, no difference in satisfaction with treatment result between the severity of symptoms at intake was found. CONCLUSIONS: The patients with the mildest symptoms at intake may not improve on symptom severity, but they do improve on functional status after simple decompression for cubital tunnel syndrome. In addition, patients with the most severe symptoms at intake do improve on both symptom severity and functional status. Moreover, all patients reported to be equally satisfied with the treatment result, which suggests that satisfaction is not dependent on the symptom severity at intake. Even those patients with both the mildest symptoms before surgery and the least improvement still seem to benefit from simple decompression. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

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.

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.

Reliability and validity of the modified McGowan grade in patients with cubital tunnel syndrome.

INTRODUCTION: This study aimed to assess the reliability and validity of the modified McGowan grading system and to determine its ability to distinguish the severity of cubital tunnel syndrome (CuTS) between the different grades. MATERIALS AND METHODS: We prospectively enrolled 39 consecutive patients with CuTS from March 2018 to December 2020. Inter- and intra-observer reliability was assessed by two orthopaedic surgeons with a minimum 2-week interval using Cohen kappa coefficients. Validity was assessed by Spearman's correlation with objective clinical outcomes (grip strength, Semmes-Weinstein monofilament test [SWMT], static two-point discrimination [2PD], and motor conduction velocity [MCV]). In addition, the relationship between the grading system and patient-reported outcomes (Disabilities of the Arm, Shoulder and Hand score and Boston Questionnaire) was evaluated using Spearman's correlation. The ability to distinguish the severity between the different grades was assessed using the Kruskal-Wallis analysis. RESULTS: The inter-observer kappa value was 0.54 and intra-observer kappa value was 0.59, which imply a moderate reliability. The modified McGowan grade had a moderate correlation with objective clinical outcomes (grip strength [r = - 0.350, p = 0.029], SWMT [r = 0.552, p < 0.001], 2PD [r = 0.456, p = 0.004], and MCV [r = - 0.394, p = 0.021]). However, patient-reported outcomes did not correlate with this grading system. Kruskal-Wallis analysis revealed significant differences between grades in terms of SWMT, 2PD, grip strength, and Boston Questionnaire functional score (p = 0.006, 0.025, 0.014, and 0.043, respectively); however, these differences were statistically significant only for a limited number of parts. CONCLUSIONS: The modified McGowan grade has a moderate inter- and intra-observer reliability. This grading system moderately correlates with objective sensory-motor functions and MCV of patients with CuTS. However, the modified McGowan grade does not reflect the patient's perceived disabilities and has a weakness in distinguishing the severity of patients' conditions among the different grades.

MRI of the ulnar nerve pre- and post-transposition: imaging features and rater agreement.

OBJECTIVE: Determine the rater agreement of MRI features of the ulnar nerve pre- and post-transposition and association with recurrent symptoms. MATERIALS AND METHODS: This IRB-approved retrospective cohort analysis examined 23 subjects who underwent elbow MRI pre- and post-ulnar nerve transposition from 1999 to 2018, 10 of whom developed recurrent symptoms. Pre- and post-transposition MRIs were evaluated by two blinded radiologists for ulnar nerve cross-sectional area, signal intensity, fascicular architecture, caliber change, and perineural scar. Inter-rater agreement was estimated using intraclass correlation coefficients (ICCs) for continuous variables and Gwet's agreement coefficient (AC) for categorical variables. Binary logistic regression modeling probed associations between imaging markers and symptom recurrence. RESULTS: The ulnar nerve, post-operatively, demonstrated statistically significant increases in size (p < 0.001), signal intensity (p = 0.021), and abrupt caliber change (p = 0.024). None of the imaging features, except for higher signal intensity of the nerve pre-transposition as demonstrated by one rater, were predictive of symptom recurrence. Inter-rater agreement for cross-sectional area measurements of the ulnar nerve at the cubital tunnel was excellent (ICCs of 0.91 and 0.83). Substantial-to-excellent inter-rater agreement was observed pre-operatively for nerve signal intensity, caliber change, and fascicular architecture. Post-operatively, agreement on nerve signal intensity and perineural scar was excellent (ACs of 0.90 and 0.88), but only slight for caliber change (0.15). CONCLUSION: Inter-rater agreement for qualitative and quantitative assessment of the ulnar nerve was generally robust. Post-transposition, the ulnar nerve was generally larger and more T2-hyperintense, but MRI features were not predictive of recurrent ulnar neuropathy, except for perhaps the signal intensity of the nerve pre-transposition.