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

Modern Treatment of Cubital Tunnel Syndrome: Evidence and Controversy

Cubital tunnel syndrome is the second most common peripheral mononeuropathy in the upper extremity. However, the diagnosis and treatment of cubital tunnel syndrome remains controversial without a standard algorithm. Although diagnosis can often be made from the patient's history and physical examination alone, electrodiagnostic studies, ultrasound, computed tomography (CT), and magnetic resonance image (MRI) can also be useful in diagnosing the disease and selecting the most appropriate treatment option. Treatment options include conservative nonoperative techniques as well as various surgical options, including in situ decompression with or without transposition, medial epicondylectomy, and nerve transfer in advanced disease. The purpose of this review is to summarize the most up-to-date literature regarding cubital tunnel syndrome and propose a treatment algorithm to provide clarity about the challenges of treating this complex patient population.

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.

Treatment outcome of tardy ulnar nerve palsy associated with traumatic cubitus valgus by supracondylar shortening wedge rotary osteotomy and ulnar nerve in situ tension release

Background

Tardy ulnar nerve palsy is a common late complication of traumatic cubitus valgus. At present, the treatment of tardy ulnar nerve palsy associated with traumatic cubitus valgus is still controversial, whether these two problems can be corrected safely and effectively in one operation is still unclear. To investigate the supracondylar shortening wedge rotary osteotomy combined with in situ tension release of the ulnar nerve in the treatment of tardy ulnar nerve palsy associated with traumatic cubitus valgus.

Methods

Between 2012 and 2019, 16 patients who had traumatic cubitus valgus deformities with tardy ulnar nerve palsy were treated with simultaneous supracondylar shortening wedge rotary osteotomy and ulnar nerve in situ tension release. we compared a series of indicators of preoperative and postoperative follow-up for at least 24 months, (1) elbow range of motion; (2) the radiographic correction of the preoperative and postoperative humerus-elbow-wrist angles; (3) the static two-point discrimination and grip strength; and (4) the preoperative and postoperative DASH scores of upper limb function. The minimum follow-up was 24 months postoperative (mean, 33 months; range, 24 ~ 44 months).

Results

The mean ROM was improved from 107 ° preoperatively to 122 ° postoperatively (P = 0.001). The mean preoperative elbow wrist angle was 24.6 °, and the mean postoperative humerus-elbow wrist angle was 12.1 ° (P < 0.001). The average grip strength and static two-point discrimination improved from 21 kgf and 8 mm to 28 kgf and 4.0 mm (P < 0.001 and P < 0.001, respectively). The ulnar nerve symptoms were improved in all patients except one. The mean HASH score improved from 29 to 16 (P < 0.001).

Conclusion

Supracondylar shortening wedge rotary osteotomy combined with in situ tension release of ulnar nerve is an effective method for the treatment of traumatic cubitus valgus with tardy ulnar nerve palsy, which restored the normal biomechanical characteristics of the affected limb and improved the elbow joint function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05324-7.

Preoperative Electrophysiology in Patients With Ulnar Nerve Entrapment at the Elbow-Prediction of Surgical Outcome and Influence of Age, Sex and Diabetes

The impact of preoperative electrophysiology on outcome of surgical treatment in ulnar nerve entrapment at the elbow (UNE) is not clarified. Our aim was to evaluate influence of preoperative electrophysiologic grading on outcome and analyse how age, sex, and in particular diabetes affect such grading. Electrophysiologic protocols for 406 UNE cases, surgically treated at two hand surgery units reporting to the Swedish National Quality Register for Hand Surgery (HAKIR; 2010-2016), were retrospectively assessed, and graded as normal, reduced conduction velocity, conduction block or axonal degeneration. Outcome of surgery after primary and revision surgery was evaluated using QuickDASH and a doctor reported outcome measure (DROM) grading. No differences in QuickDASH or DROM were found between the four groups with different electrophysiologic grading preoperatively, or at three and 12 months or at follow up, respectively. When dichotomizing the electrophysiologic grading into normal and pathologic electrophysiology, cases with normal electrophysiology had worse QuickDASH than cases with pathologic electrophysiology preoperatively (p=0.046). Presence of a conduction block or axonal degeneration indicated a worse outcome by DROM grading (p=0.011). Primary surgeries had electrophysiologic more pronounced nerve pathology compared to revision surgeries (p=0.017). Cases of older age, men, and those with diabetes had more severe electrophysiologic nerve affection (p&lt;0.0001). In the linear regression analysis, increasing age (unstandardized B=0.03, 95% CI 0.02-0.04; p&lt;0.0001) and presence of diabetes (unstandardized B=0.60, 95% CI 0.25-0.95; p=0.001) were associated with a higher risk of a worse electrophysiologic classification. Female sex was associated with a better electrophysiologic grading (unstandardized B=-0.51, 95% CI -0.75- -0.27; p&lt;0.0001). We conclude that older age, male sex, and concomitant diabetes are associated with more severe preoperative electrophysiologic nerve affection. Preoperative electrophysiologic grade of ulnar nerve affection may influence surgical outcome.

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.

Ultrasonography of the ulnar nerve in the elbow: video article

Disorders affecting the ulnar nerve in the elbow are common in clinical practice. The diagnosis is based on clinical evaluation and electrodiagnostic tests, but imaging examinations are frequently necessary, particularly for the identification of the structures associated with nerve compression. The purpose of this video article is to review the anatomy, the pathology, scanning techniques, and sonographic appearance of the ulnar nerve in the elbow.

Ulnar neuropathy and medial elbow pain in women's fastpitch softball pitchers: a report of 6 cases

BACKGROUND

Elite-level women's fastpitch softball players place substantial biomechanical strains on the elbow that can result in medial elbow pain and ulnar neuropathic symptoms. There is scant literature reporting the expected outcomes of the treatment of these injuries. This study examined the results of treatment in a series of these patients.

METHODS

We identified 6 female softball pitchers (4 high school and 2 collegiate) with medial elbow pain and ulnar neuropathic symptoms. Trials of conservative care failed in all 6, and they underwent surgical treatment with subcutaneous ulnar nerve transposition. These patients were subsequently monitored postoperatively to determine outcome.

RESULTS

All 6 female pitchers had early resolution of elbow pain and neuropathic symptoms after surgical treatment. Long-term follow-up demonstrated that 1 patient quit playing softball because of other injuries but no longer reported elbow pain or paresthesias. One player was able to return to pitching at the high school level but had recurrent forearm pain and neuritis 1 year later while playing a different sport and subsequently stopped playing competitive sports. Four patients continued to play at the collegiate level without further symptoms.

CONCLUSIONS

Medial elbow pain in women's softball pitchers caused by ulnar neuropathy can be treated effectively with subcutaneous ulnar nerve transposition if nonsurgical options fail. Further study is necessary to examine the role of overuse, proper training techniques, and whether pitching limits may be necessary to avoid these injuries.

Medial elbow pain

Medial elbow pain is uncommon when compared with lateral elbow pain.

Medial epicondylitis is an uncommon diagnosis and can be confused with other sources of pain.

Overhead throwers and workers lifting heavy objects are at increased risk of medial elbow pain.

Differential diagnosis includes ulnar nerve disorders, cervical radiculopathy, injured ulnar collateral ligament, altered distal triceps anatomy or joint disorders.

Children with medial elbow pain have to be assessed for ‘Little League elbow’ and fractures of the medial epicondyle following a traumatic event.

This paper is primarily focused on the differential diagnosis of medial elbow pain with basic recommendations on treatment strategies.

Cite this article: EFORT Open Rev 2017;2:362-371. DOI: 10.1302/2058-5241.2.160006