Clinical results versus subjective improvement with anterior transposition in cubital tunnel syndrome

Classifying the Severity of Cubital Tunnel Syndrome: A Preoperative Grading System Incorporating Electrodiagnostic Parameters

BACKGROUND

Current classifications for cubital tunnel syndrome have not been shown to reliably predict postoperative outcomes. In this article, the authors introduce a new classification that incorporates clinical and electrodiagnostic parameters, including compound muscle action potential amplitude, to classify the preoperative severity of cubital tunnel syndrome. The authors compare this to established classifications and evaluate its association with patient-rated improvement.

METHODS

The authors reviewed 44 patients who were treated surgically for cubital tunnel syndrome. Patients were retrospectively classified using their proposed classification and the Akahori, McGowan-Goldberg, Dellon, and Gu classifications. Correlation of grades was assessed by Spearman coefficients and agreement was assessed by weighted kappa coefficients. Patient-reported impairment was assessed using the Disabilities of the Arm, Shoulder, and Hand questionnaire before and after surgery.

RESULTS

The classifications tended to grade patients in a similar way, with Spearman coefficients of 0.60 to 0.85 ( p < 0.0001) and weighted kappa coefficients of 0.46 to 0.71 ( p < 0.0001). Preoperative Disabilities of the Arm, Shoulder, and Hand scores increased with severity grade for most classifications. In multivariable analysis, the authors' classification predicted postoperative Disabilities of the Arm, Shoulder, and Hand score improvement, whereas established classifications did not.

CONCLUSIONS

Established classifications are imperfect indicators of preoperative severity. The authors introduce a preoperative classification for cubital tunnel syndrome that incorporates electrodiagnostic findings in addition to classic signs and symptoms.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, III.

Safety and Outcomes of Different Surgical Techniques for Cubital Tunnel Decompression: A Systematic Review and Network Meta-analysis

IMPORTANCE

Cubital tunnel syndrome is the second most common compressive neuropathy, affecting 6% of the population. Numerous different operations are performed globally to treat it; however, prior conventional (pairwise) meta-analyses have been unable to determine which procedure is associated with the best outcomes and fewest complications.

OBJECTIVE

To evaluate which operation for cubital tunnel syndrome is associated with the greatest likelihood of symptomatic cure.

DATA SOURCES

PubMed, EMBASE, and CENTRAL were searched from database inception to March 2, 2019, with no restrictions on the setting or design of studies.

STUDY SELECTION

Experimental and observational studies directly comparing the outcomes of at least 2 surgical treatments for adults with primary cubital tunnel syndrome were included. Case reports were excluded, and when comparative studies had subgroups with 1 participant, the single-participant subgroup was excluded. The treatments had to be in situ decompression with or without medial epicondylectomy or an anterior subcutaneous, subfascial, intramuscular, or submuscular transposition. The access could be open, minimally invasive, or endoscopic. The comparator could be sham surgery or any operation mentioned earlier.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by 2 independent reviewers, following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline and the PRISMA Network Meta-analysis extension statement. Network meta-analysis was used to estimate the relative efficacy and safety associated with interventions using relative risks. Surgical techniques were ranked by their probability of being the best (P score) and interpreted in terms of their clinical impact.

MAIN OUTCOMES AND MEASURES

The primary outcome was response to treatment (ie, symptomatic improvement). The secondary outcomes were perioperative complications, reoperation, and recurrence.

RESULTS

A total of 30 studies of 2894 limbs undergoing 8 different operations were included. Across the studies, 56% of participants were men, the mean (SD) age was 48 (8) years, and patients had symptoms for a mean (SD) of 15 (7) months. Overall, 87% (95% CI, 92%-91%) of patients improved with surgery; all forms of in situ decompression were more effective than any type of transposition procedure; for example, open in situ decompression with epicondylectomy was associated with higher success rates than subcutaneous transposition (relative risk, 1.13; 95% CI, 1.01-1.25). Postoperatively, 3% (95% CI, 2%-4%) of patients developed complications, and in situ decompressions were ranked as the least risky, although there was considerable uncertainty in this outcome. Overall, 2% (95% CI, 1%-3%) of patients required reoperation; open in situ decompression was associated with the fewest reoperations; in comparison, submuscular transposition was associated with 5 times the risk of reoperation (relative risk, 5.08; 95% CI, 2.06-12.52). During surveillance, 3% (95% CI, 1%-4%) of patients developed recurrence, and open in situ decompression with epicondylectomy was ranked as the safest operation, although there was uncertainty in the estimates.

CONCLUSIONS AND RELEVANCE

In this network meta-analysis, open in situ decompression (with or without medial epicondylectomy) appeared to be the safest operation and also was associated with the best outcomes for patients with primary cubital tunnel syndrome. Future research should focus on better defining this disorder and developing core outcome measures.

Reporting Outcomes and Outcome Measures in Cubital Tunnel Syndrome: A Systematic Review

PURPOSE

Comparison between studies assessing outcomes after surgical treatment of cubital tunnel syndrome (CuTS) has proven to be difficult owing to variations in outcome reporting. This study aimed to identify outcomes and outcome measures used to evaluate postoperative results for CuTS.

METHODS

We performed computerized database searches of MEDLINE and EMBASE. Studies with 20 or more patients aged 18 and older who were undergoing medial epicondylectomy, endoscopic decompression, open simple decompression, or decompression with subcutaneous, submuscular, or intramuscular transposition for ulnar neuropathy at the elbow were included. Outcomes and outcome measures were extracted and tabulated.

RESULTS

Of the 101 studies included, 45 unique outcomes and 31 postoperative outcome measures were identified. These included 7 condition-specific, clinician-reported instruments; 4 condition-specific, clinician-reported instruments; 8 patient-reported, generic instruments; 11 clinician-generated instruments; and one utility measure. Outcome measures were divided into 6 unique domains. Overall, 60% of studies used condition-specific outcome measures. The frequency of any condition-specific outcome measure ranged from 1% to 37% of included studies.

CONCLUSIONS

There is marked heterogeneity in outcomes and outcome measures used to assess CuTS. A standardized core outcome set is needed to compare results of various techniques of cubital tunnel decompression.

CLINICAL RELEVANCE

This study builds on the existing literature to support the notion that there is marked heterogeneity in outcomes and outcome measures used to assess CuTS. The authors believe that a future standardized set of core outcomes is needed to limit heterogeneity among studies assessing postoperative outcomes in CuTS to compare these interventions more easily and pool results in the form of systematic reviews and meta-analyses.

Subcutaneous Versus Submuscular Anterior Transposition of the Ulnar Nerve for Cubital Tunnel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Observational Studies

Subcutaneous and submuscular anterior ulnar nerve transposition have been widely used in patients with cubital tunnel syndrome. However, the reliable evidence in favor of 1 of 2 surgical options on clinical improvement remains controversial. To maximize the value of the available literature, we performed a systematic review and meta-analysis to compare subcutaneous versus submuscular anterior ulnar nerve transposition in patients with ulnar neuropathy at the elbow. PubMed, Cochrane Library, and EMBASE databases were searched for randomized and observational studies that compared subcutaneous transposition with submuscular transposition of ulnar nerve for cubital tunnel syndrome. The primary outcome was clinically relevant improvement in function compared to the baseline. Randomized and observational studies were separately analyzed with relative risks (RRs) and 95% confidence intervals (CIs). Two randomized controlled trials (RCTs) and 7 observational studies, involving 605 patients, were included. Our meta-analysis suggested that no significant differences in the primary outcomes were observed between comparison groups, both in RCT (RR, 1.16; 95% CI 0.68-1.98; P = 0.60; I2= 81%) and observational studies (RR, 1.01; 95% CI 0.95-1.08; P = 0.69; I2 = 0%). These findings were also consistent with all subgroup analyses for observational studies. In the secondary outcomes, the incidence of adverse events was significantly lower in subcutaneous group than in submuscular group (RR, 0.54; 95% CI 0.33-0.87; P = 0.01; I2 = 0%), whereas subcutaneous transposition failed to reveal more superiority than submuscular transposition in static two-point discrimination (MD, 0.04; 95% CI -0.18-0.25; P = 0.74; I = 0%). The available evidence is not adequately powered to identify the best anterior ulnar nerve transposition technique for cubital tunnel syndrome on the basis of clinical outcomes, that is, suggests that subcutaneous and submuscular anterior transposition might be equally effective in terms of postoperative clinical improvement. However, differences in clinical outcomes metrics should be noted, and these findings largely rely on the outcomes data from observational studies that are potentially subject to a high risk of selection bias. Therefore, more high-quality and adequately powered RCTs with standardized clinical outcomes metrics are necessary for proper comparison of these techniques.

Entrapment neuropathy of the wrist, forearm, and elbow

This review discusses key diagnostic points and treatment guidelines for compression neuropathies of the wrist, forearm, and elbow. Recent treatment progress is reviewed, controversies are highlighted, and consensus is summarized. Limited or mini-open releases and endoscopic carpal tunnel releases are considered equally safe and efficient. Both methods are currently mainstays of surgical treatment.

Recurrent ulnar nerve entrapment at the elbow: Correlation of surgical findings and 3-Tesla magnetic resonance neurography

The authors describe the correlation between 3-Tesla magnetic resonance neurography (MRN) and surgical findings in two patients who underwent multiple previous failed ulnar nerve surgeries. MRN correctly localized the site of the abnormality. Prospectively observed MRN findings of perineural fibrosis, ulnar nerve re-entrapment abnormalities, medial antebrachial cutaneous neuroma and additional median nerve entrapment were confirmed surgically.

Ulnar neuropathy at the elbow: an evidence-based algorithm

Ulnar neuropathy at the elbow is the second most common compression neuropathy of the upper extremity and poses a challenge for treating physicians. Lack of a standardized grading system, outcome measures, or surgical indications can make treatment decisions difficult to justify. Conclusions drawn from the available literature include similar rates of good to excellent outcomes for in situ decompression; transposition in the subcutaneous, submuscular, or intramuscular planes; and endoscopic decompression. Outcomes for revision surgery are generally less favorable. Development of standardized outcomes measures will be important in improving the quality and comparability of the literature on this subject.

Outcomes measures used to assess results after surgery for cubital tunnel syndrome: a systematic review of the literature

PURPOSE

The primary objective of this systematic review was to identify and analyze the outcomes measures that have been used to evaluate postoperative results following surgery for cubital tunnel syndrome. The secondary objective was to compare the postoperative results among patients evaluated using patient-satisfaction instruments to those evaluated using surgeon-reported scales.

METHODS

Computerized database searches of MEDLINE, EMBASE, and MEDLINE In-Process were performed. Studies involving adults with cubital tunnel syndrome in whom the surgical intervention was simple decompression, anterior transposition (subcutaneous, submuscular or intramuscular), endoscopic decompression, or medial epicondylectomy were included. A systematic review was performed that included randomized controlled trials, comparative observational studies, noncomparative observational studies, and case series.

RESULTS

This systematic review of the literature identified 42 studies that satisfied the inclusion criteria. The authors identified 21 health outcomes measures used in cubital tunnel studies. These consisted of 2 generic instruments; 10 symptom-specific, author-reported instruments; 3 symptom-specific, patient-reported instruments; and 6 patient questionnaires. No measure demonstrated adequate development or validation for use in its target population. Available data revealed a consistently high level of patient satisfaction following simple decompression or submuscular transposition (65% to 92%). The results of the author-reported, symptom-specific scales varied widely and showed no obvious association with patient satisfaction. The variation in reporting of results prevented statistical comparisons between author-reported results and patient-reported results.

CONCLUSIONS

To the best of our knowledge, this is the first systematic review to delineate the outcomes measures used to evaluate the treatment of cubital tunnel syndrome. Our results show that reliable, reproducible, and valid outcomes measures are lacking from the surgical literature. A standardized assessment protocol for ulnar neuropathy is required for future comparison trials.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Subcutaneous vs Submuscular Ulnar Nerve Transposition in Moderate Cubital Tunnel Syndrome

Background:

The surgical treatment of Cubital tunnel syndrome (CubTS) is still a matter of debate. No consensus exists about the necessity of anterior transposition of the ulnar nerve after decompression. However, this technique is fairly common in clinical practice.

Material and Methodology:

In the present study we compared the operative technique (incision length, operative time), postoperative care (postoperative pain and complications) and the outcome between subcutaneous transposition and submuscular transposition of the ulnar nerve as two surgical modalities in treating moderate CubTS.

Between March 2004 and March 2007, twenty six patients with moderate CubTS (according to Dellon’s grading system) were stratified according to age and gender into these two surgical techniques. The two groups were prospectively followed up 2 weeks, 6 months and 12 months postoperatively by the same observer and the operation outcome was assessed using the Bishop rating system.

Results:

We found that the subcutaneous transposition of the ulnar nerve was associated with shorter incision, shorter operative time, less postoperative pain, less postoperative complication and better outcome compared with the submuscular transposition.

Conclusion:

The authors recommend the subcutaneous technique when considering anterior transposition of the ulnar nerve in treating moderate CubTS.