Clinical classification and treatment of 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.

Ulnar neuropathy at the elbow in 413 Japanese patients: An assessment of pathological elbow lesions and neurological severity

BACKGROUND

Various pathological elbow lesions are often complicated with ulnar neuropathy at the elbow (UNE), although the precise pathology, incidence, and clinical and neurological features of these lesions have not been identified. We therefore investigated elbow pathology and neurological severity in Japanese patients with UNE.

METHODS

The medical records of 457 Japanese UNE patients who were surgically treated among 6 hospitals were retrospectively examined. Eligible patients had UNE diagnosed by physical findings and nerve conduction studies according to the criteria of the American Association of Electrodiagnostic Medicine. The elbows were analyzed with regard to age, gender, occupation, pathology at the elbow, and severity of nerve palsy.

RESULTS

A total of 398 patients with 413 UNE elbows of a mean age of 63 years (range: 15-87) met the inclusion criteria. UNE elbows were predominantly in male patients (69.0%). Overall, 310 elbows (75.1%) had 1 or more elbow lesions: 238 elbows (76.8%) had a single lesion and 72 elbows (23.3%) had 2 or more lesions. The most common lesion was primary elbow osteoarthritis (EOA) occurring in 54.5% of elbows, followed next by medial elbow ganglion in 8.5% and cubitus valgus in 6.5%. Most elbows with medial elbow ganglion or cubitus valgus were associated with EOA. Entrapment sites were at the cubital tunnel in 84.5%-91.3% of UNE elbows, regardless of an association with elbow lesion. The incidence of McGowan grade III lesion was 50.8% in elbows with primary EOA, which was higher than the 35.0% in elbows with no lesion.

CONCLUSIONS

This study revealed that UNE had various isolated or combined elbow lesions. In Japanese UNE, primary or secondary EOA was found in 62.2% of cases and severe motor weakness was noted in 47.2%. The incidences of EOA and severe ulnar nerve palsy in the Japanese UNE are higher than those in Caucasians.

LEVEL OF EVIDENCE

Level IV; Prognostic-Investigating the effect of a patient characteristic on the outcome of a disease; Case series.

Compound Muscle Action Potential Amplitude Predicts the Severity of Cubital Tunnel Syndrome

BACKGROUND

Cubital tunnel syndrome has a spectrum of presentations ranging from mild paresthesias to debilitating numbness and intrinsic atrophy. Commonly, the classification of severity relies on clinical symptoms and slowing of conduction velocity across the elbow. However, changes in compound muscle action potential (CMAP) amplitude more accurately reflect axonal loss. We hypothesized that CMAP amplitude would better predict functional impairment than conduction velocity alone.

METHODS

A retrospective cohort of patients who underwent a surgical procedure for cubital tunnel syndrome over a 5-year period were included in the study. All patients had electrodiagnostic testing performed at our institution. Clinical and electrodiagnostic variables were recorded. The primary outcome was preoperative functional impairment, defined by grip and key pinch strength ratios. Multivariable regression identified which clinical and electrodiagnostic variables predicted preoperative functional impairment.

RESULTS

Eighty-three patients with a mean age of 57 years (75% male) were included in the study. The majority of patients (88%) had abnormal electrodiagnostic studies. Fifty-four percent had reduced CMAP amplitude, and 79% had slowing of conduction velocity across the elbow (recorded from the first dorsal interosseous). On bivariate analysis, older age and longer symptom duration were significantly associated (p < 0.05) with reduced CMAP amplitude and slowing of conduction velocity across the elbow, whereas body mass index (BMI), laterality, a primary surgical procedure compared with revision surgical procedure, Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire scores, and visual analog scale (VAS) scores for pain were not. Multivariable regression analysis demonstrated that reduced first dorsal interosseous CMAP amplitude independently predicted the loss of preoperative grip and key pinch strength and that slowed conduction velocity across the elbow did not.

CONCLUSIONS

Reduced first dorsal interosseous amplitude predicted preoperative weakness in grip and key pinch strength, and isolated slowing of conduction velocity across the elbow did not. CMAP amplitude is a sensitive indicator of axonal loss and an important marker of the severity of cubital tunnel syndrome. It should be considered when counseling patients with regard to their prognosis and determining the necessity and timing of operative intervention.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effect of dry needling on cubital tunnel syndrome: Three case reports

This case series describes three patients who presented with right medial elbow pain managed unsuccessfully with conservative treatment that included medication, massage, exercise therapy, ultrasound therapy, neurodynamic mobilization, and taping. Diagnosis of cubital tunnel syndrome was based on palpatory findings, a positive elbow flexion test, and a positive Tinel's sign. Conventionally, the intervention for this entrapment has been surgical decompression, with successful outcomes. This is potentially a first-time description of the successful management of cubital tunnel syndrome with dry needling (DN) using a recently published DN grading system. The patients were seen twice a week for 2 weeks with immediate improvements noted in all the outcome measures after the first treatment session. At discharge, they were pain-free and fully functional, which was maintained up to a 6-month follow-up.

Muscular atrophy in severe cases of cubital tunnel syndrome: prognostic factors and outcome after surgical treatment

BACKGROUND

Cubital tunnel syndrome (CuTS) is a frequent neuropathy, leading to sensor-motoric dysfunction. Many patients even present with muscular atrophy as a sign for severe and long-lasting nerve impairment, usually suggesting unfavourable outcome. We analysed if those patients benefit from surgical treatment on a long-term basis.

METHODS

Between January 2010 and March 2015, 42 consecutive cases of CuTS with atrophy of the intrinsic hand muscles were surgically treated in our department. Clinical data of the treatment course and postoperative results were collected. Follow-up was prospectively assessed according to McGowen grading and Bishop outcome score. Mean follow-up time was 39.8 (±17.0) months.

RESULTS

All patients were treated with in situ decompression; in 33%, submuscular transposition was performed. Forty-five percent showed improvement of sensory deficits and 57% showed improvement of motor deficits 6 months after the operation. Atrophy improved in 76%. At the time of follow-up, 79% were satisfied with the postoperative result and 77% of patients reached good or excellent outcome according to modified Bishop rating scale. Patients with improvement of atrophy had significantly shorter symptom duration period (7 ± 10 months vs 26 ± 33 months; p < 0.05). In the case of intraoperative pseudoneuroma observation, atrophy improvement was less likely (p < 0.05).

CONCLUSIONS

In severe cases of CuTS with atrophy of the intrinsic hand muscles, surgical treatment enables improvement of sensory function, motor function and atrophy even in cases with muscular atrophy. Atrophy improvement was more likely in cases of short symptom duration and less likely in cases with pseudoneuroma.

Surgical management of the elderly elbow

The elbow has a major role in helping with the positioning of the hand in space. Any pathology of the joint can result in pain, loss of function and difficulties with activities of daily living. With an increasingly elderly population the degenerative conditions affecting the elbow are becoming more prevalent. Besides traumatic injury, the more commonly encountered problems are osteoarthritis, inflammatory arthritis, nerve compression and stiffness. An awareness of these conditions is important for those who provide care to this patient group. Whilst many of these conditions can be managed conservatively in primary care, some patients are referred to secondary care and elect for surgical treatments. This review considers the surgical treatments for the common elbow pathologies in the elderly population, including the potential complications associated with such treatments.

IS RDW A PREDICTIVE PARAMETER FOR CUBITAL TUNNEL SYNDROME PATIENTS REQUIRING SURGERY?

OBJECTIVE

The aim of this study was to investigate whether haemogram parameters are predictive factors for both the severity of the disease and a decision in favor of surgical treatment in patients with an established diagnosis of cubital tunnel syndrome (CuTS) .

METHODS

The medical files of patients with a diagnosis of CuTS who were followed-up conservatively (n=92) or surgically treated (n=92) were retrospectively screened and the haemogram parameters were recorded .

RESULTS

The receiver operating characteristic (ROC) curve analysis revealed an area of 0.665 under the curve, with 76.3% sensitivity and 84.8% specificity at the cut-off of a red cell distribution width (RDW) level grater than 15.45%. RDW levels higher than 15.5%, electromyography (EMG) severity, and a clinical score higher than three were found to be independently associated with surgery .

CONCLUSION

An elevated RDW value was related to the severity of the electromyogram. RDW may, therefore, be a useful independent predictor for the decision to surgical treatment of CuTS. Level of Evidence III, Retrospective Study.

Anterior subcutaneous transposition of the ulnar nerve improves neurological function in patients with cubital tunnel syndrome

Although several surgical procedures exist for treating cubital tunnel syndrome, the best surgical option remains controversial. To evaluate the efficacy of anterior subcutaneous transposition of the ulnar nerve in patients with moderate to severe cubital tunnel syndrome and to analyze prognostic factors, we retrospectively reviewed 62 patients (65 elbows) diagnosed with cubital tunnel syndrome who underwent anterior subcutaneous transposition. Preoperatively, the initial severity of the disease was evaluated using the McGowan scale as modified by Goldberg: 18 patients (28%) had grade IIA neuropathy, 20 (31%) had grade IIB, and 27 (42%) had grade III. Postoperatively, according to the Wilson & Krout criteria, treatment outcomes were excellent in 38 patients (58%), good in 16 (25%), fair in 7 (11%), and poor in 4 (6%), with an excellent and good rate of 83%. A negative correlation was found between the preoperative McGowan grade and the postoperative Wilson & Krout score. The patients having fair and poor treatment outcomes had more advanced age, lower nerve conduction velocity, and lower action potential amplitude compared with those having excellent and good treatment outcomes. These results suggest that anterior subcutaneous transposition of the ulnar nerve is effective and safe for the treatment of moderate to severe cubital tunnel syndrome, and initial severity, advancing age, and electrophysiological parameters can affect treatment outcome.