Ulnar Neuropathy after Distal Radius Fractures - A Case Series and Review of Literature.

Background: Ulnar neuropathy after a distal radius fracture is rare and has limited reports in literature. As such, there is no consensus regarding the optimal treatment and management of such injuries. We report our experience with managing these uncommon injuries. Methods: A retrospective review was conducted where patients presenting with ulnar neuropathy after sustaining a distal radius fracture were identified from January 2021 to December 2023 from our hospital database. Results: A total of four patients were identified. All of them underwent surgical fixation for their respective fractures. None of them underwent immediate or delayed exploration and decompression of the ulnar nerve. All patients had clinical improvement at 3 months after their initial injuries. Three patients eventually had resolution of the neuropathy between 5 and 9 months post injury, while one had partial recovery and developed a neuroma but declined surgery due to symptoms minimally affecting work and daily activities. Conclusions: Ulnar neuropathy after distal radius fractures may not be as rare as previously thought. Expectant management of the neuropathy would be a reasonable treatment as long as there is no evidence of nerve discontinuity or translocation and that there is clinical and/or electrodiagnostic improvement at 3-4 months after the initial injury. Level of Evidence: Level IV (Therapeutic).

Core outcomes in nerve surgery: development of a core outcome set for ulnar neuropathy at the elbow.

OBJECTIVE: Ulnar neuropathy at the elbow (UNE) is common, affecting 1%-6% of the population. Despite this, there remains a lack of consensus regarding optimal treatment. This is primarily due to the difficulty one encounters when trying to assess the literature. Outcomes are inconsistently reported, which makes comparing studies or developing meta-analyses difficult or even impossible. Thus, there is a need for a core outcome set (COS) for UNE (COS-UNE) to help address this problem. The objective of this study was to utilize a modified Delphi method to develop COS-UNE. METHODS: A 5-stage approach was utilized to develop COS-UNE: stage 1, consortium development; 2, literature review to identify potential outcome measures; 3, Delphi survey to develop consensus on outcomes for inclusion; 4, Delphi survey to develop definitions; and 5, consensus meeting to finalize the COS and definitions. The study followed the Core Outcome Set-STAndards for Development (COS-STAD) recommendations. RESULTS: The Core Outcomes in Nerve Surgery (COINS) Consortium comprised 21 participants, all neurological surgeons representing 11 countries. The final COS-UNE consisted of 22 data points/outcomes covering the domains of demographic characteristics, diagnostics, patient-reported outcomes, motor/sensory outcomes, and complications. Appropriate instruments, methods of testing, and definitions were set. The consensus minimum duration of follow-up was 6 months, with the consensus optimal timepoints for assessment identified as preoperatively and 3, 6, and 12 months postoperatively. CONCLUSIONS: The authors identified consensus data points/outcomes and also provided definitions and specific scales to be utilized to help ensure that clinicians are consistent in their reporting across studies on UNE. This COS should serve as a minimum set of data to be collected in all future neurosurgical studies on UNE. The authors hope that clinicians evaluating ulnar neuropathy will incorporate this COS into routine practice and that future studies will consider this COS in the design phase.

Ulnar Nerve Neuropathy After Surgery for Intraarticular Distal Humerus Fractures: An Analysis of 116 Patients.

PURPOSE: To identify the incidence and the factors associated with a postoperative ulnar nerve neuropathy in patients who had undergone open reduction and internal fixation for intraarticular distal humerus fractures. METHODS: We retrospectively reviewed 116 patients who had undergone surgery between January 2011 and December 2020. Age, sex, BMI, mechanism of injury, open or closed fracture, operation time, tourniquet time, and nerve injury at the final examination were collected from medical charts. We essentially used the paratricipital approach. In cases in which the reduction of intraarticular bone fragments was difficult, olecranon osteotomy was used. Ulnar nerve function was graded according to a modified system of McGowan. We conducted logistic regression analysis to investigate factors of neuropathy using items identified as statistically significant in univariate analysis as explanatory variables. RESULTS: Thirty-four patients (29.3%) had persistent neuropathy at the final follow-up. In the modified McGowan classification, 28 patients had grade 1 and 6 patients had grade 2 neuropathy. Olecranon osteotomy emerged as a distinct explanatory variable for the prophylaxis of ulnar nerve neuropathy in the multivariate analysis (odds ratio, 0.30; 95% confidence interval, 0.12-0.73). Anterior transposition, however, was not a statistically significant factor (odds ratio, 1.91; 95% confidence interval, 0.81-4.56). CONCLUSIONS: Olecranon osteotomy was the only independent factor associated with preventing the occurrence of ulnar nerve neuropathy. Ulnar nerve transposition might not be associated with prevention of ulnar nerve neuropathy. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Abductor Digiti Minimi and Anterior Interosseous to Ulnar Motor Nerve Transfer: The Super Turbocharge End-to-Side Transfer.

SUMMARY: Anterior interosseous nerve to ulnar motor nerve supercharged end-to-side (SETS) nerve transfer to restore intrinsic function is a recently adopted nerve transfer in severe ulnar neuropathy. Its success is predicated on the critical threshold number of axons innervating the intrinsic muscles. Given the relative expendability of the abductor digiti minimi (ADM) muscle and the critical function of the other intrinsic muscles, the authors modified their SETS transfer to redirect axons from the ADM to turbocharge the ulnar motor nerve to innervate the more critical intrinsic muscles. They refer to this procedure as a super turbocharged end-to-side (STETS) procedure. The ADM has been used previously as a muscle/tendon transfer for thumb opposition and more recently as a nerve transfer to reinnervate the thenar branch of the median nerve. Although current methods of assessment of reinnervation are likely unable to differentiate between contributions from the anterior interosseous nerve SETS versus ADM STETS transfer, this technique follows the fundamentals of modern nerve surgery, where directing the maximum number of nerve fibers in a timely fashion to the most critical target is paramount for the best functional recovery. The authors suggest that the STETS technique may optimize outcomes in ulnar neuropathy without additional patient morbidity.

Compound Muscle Action Potential Amplitude as a Predictor of Functional and Patient-Reported Outcomes in Ulnar Neuropathy at the Elbow.

BACKGROUND: Ulnar neuropathy at the elbow (UNE) is a debilitating upper extremity condition that often leaves patients with residual symptoms even after surgical treatment. The role of electrodiagnostic studies in guiding the treatment of UNE is not well established, and conventional electrodiagnostic parameters may not reflect the severity of disease. Compound muscle action potential (CMAP) amplitude is a parameter that corresponds with axonal injury and motor symptoms and may more accurately predict the severity of neurologic injury. METHODS: This prospective multicenter study recruited 78 patients in the Surgery of the Ulnar Nerve project. Patients underwent electrodiagnostic testing and clinical assessment of motor and sensory function, and completed patient-reported outcome questionnaires, including the Michigan Hand Outcome Questionnaire; the Disabilities of the Arm, Shoulder and Hand questionnaire; and the Carpal Tunnel Questionnaire (CTQ). Correlations were measured among each of the electrodiagnostic parameters and outcomes and predictive models for each outcome were subsequently developed. RESULTS: Of all the electrodiagnostic parameters measured, only CMAP amplitude was predictive of scores on the Michigan Hand Outcome Questionnaire; Disabilities of the Arm, Shoulder and Hand questionnaire; CTQ function scale, and motor impairment in grip and pinch strength. None of the parameters were predictive of scores on the CTQ symptom scale or sensory impairments as measured with two-point discrimination or Semmes-Weinstein monofilament testing. CONCLUSIONS: CMAP amplitude, but not other conventional electrodiagnostic parameters, is predictive of functional outcomes in UNE. This electrodiagnostic measurement can alert the clinician to severe cases of UNE and inform surgical decision-making. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Electrodiagnostic Predictors of Outcomes After In Situ Decompression of the Ulnar Nerve.

PURPOSE: Patients with severe ulnar neuropathy at the elbow frequently experience suboptimal surgical outcomes. Clinical symptoms alone may not accurately represent the severity of underlying nerve injury, calling for objective assessment tools, such as electrodiagnostic studies. The goal of our study was to determine whether specific electrodiagnostic parameters can be used to predict the outcomes after in situ decompression of the ulnar nerve. METHODS: This prospective study enrolled consecutive patients aged ≥18 years diagnosed with ulnar neuropathy at the elbow. Patients completed a baseline battery of motor, sensory, functional, and electrodiagnostic tests before undergoing in situ decompression of the ulnar nerve. They were reassessed at 6 weeks, 3 months, 6 months, and 12 months after surgery. Forty-two patients completed at least 2 follow-up assessments and were included in the study. RESULTS: When controlling for other electrodiagnostic measurements and demographic factors, none of the electrodiagnostic parameters were predictive of outcomes at 12 months after surgery. Patients with decreased compound muscle action potential amplitudes demonstrated slower trends of recovery in grip strength, pinch strength, and overall scores on the Michigan Hand Outcomes Questionnaire as well as its function, work, and activities of daily living subscales, Disabilities of the Arm, Shoulder, and Hand questionnaire, and the Carpal Tunnel Questionnaire. Decreased motor nerve conduction velocity was predictive of slower recovery of 2-point discrimination and pinch strength. CONCLUSIONS: Compound muscle action potential amplitude, but not other conventional electrodiagnostic parameters, was predictive of functional outcomes after in situ decompression of the ulnar nerve. This parameter should play a role in determining the timing and prognosis of treatment for ulnar neuropathy at the elbow. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Dynamic Rather than Static Procedures in Correcting Claw Deformities Due to Ulnar Nerve Palsy.

The theoretic disadvantage of dynamic tendon transfers is the perception that they are "more complex" than static procedures. The latter may provide a simple solution to claw deformity in a subset of patients; however, they completely disregard the disability associated with loss of the intrinsic musculature. Dynamic procedures reconstruct in part the deficient intrinsic forces and are thus capable of correcting the deformity and some disabilities associated with ulnar nerve palsy. In our practice, we have consistently achieved reasonable correction of claw deformity and improvement in tendon synchrony and grip strength with a modified Stiles-Bunnell, flexor digitorum superficialis tendon transfer.

Evaluation of functional recovery in the intrinsic and flexor muscles after nerve transfer for ulnar nerve lesion. A new measurement method: The Cha method.

"Supercharge" end-to-side (SETS) nerve transfer for lesions of the proximal ulnar nerve is a recognized novel option, but improvement in motor function after surgery has not been properly evaluated. We therefore propose a modified method for quantitative evaluation of improvement in the intrinsic hand strength. We screened 216 patients with proximal ulnar nerve lesions who presented to our outpatient department from 2012 to 2020. Of these, 101 met our inclusion/exclusion criteria and were evaluated just before surgery. We used a novel method to measure finger abduction ("2nd-abd"), adduction ("5th-add"), and ring and little finger flexion strength ("4,5 grip"), and analyzed correlations with established pinch strength data. The male:female sex ratio was 86:15, and the ratio dominant to nondominant arm involvement was 68:33. All strength measurements were analyzed as percentage affected to contralateral normal side. On Pearson correlation analysis, the strength ratios for "4,5 grip", "2nd-abd", and "5th-add", but not "5 fingers (total) grip", showed significant positive correlation with key and oppositional pinch strength (all p < 0.001). Additionally, linear regression analysis showed identical results for each strength correlation with key/oppositional pinch, except for "5 fingers total) grip" (all, p < 0.001). SETS is a reasonable alternative for lesions of the proximal ulnar nerve. The measurement method we propose is feasible for specific assessment of intrinsic muscle strength, which improves after surgery. LEVEL OF EVIDENCE: Diagnostic, level IV.

Anterior interosseous nerve neuropathy in a patient with spinal cord injury: case report and literature review.

INTRODUCTION: Entrapment neuropathies, typically carpal tunnel syndrome and ulnar neuropathy, frequently occur in patients with spinal cord injury (SCI). Upper limb impairments due to entrapment neuropathy can be particularly debilitating in this population. Anterior interosseous nerve (AIN) neuropathy has not been previously described in the SCI population. CASE PRESENTATION: A 27-year-old left-handed man with a history of C7 ASIA Impairment Scale B spinal cord injury five years prior presented to clinic with decreased left thumb function as well as thumb flexion. Workup including nerve conduction studies, electromyogram, ultrasonographic assessment, and magnetic resonance neurography was consistent with compressive AIN neuropathy. Surgical exploration and neurolysis was performed, with improvement of symptoms. DISCUSSION: Entrapment neuropathies should be carefully considered in the evaluation of patients with SCI with new motor deficits. We report a case of AIN neuropathy in a patient with SCI successfully treated with surgical decompression, and review the literature describing upper extremity entrapment neuropathies in this population. Surgical decompression is an effective option for treatment of AIN neuropathy in the setting of SCI, though further characterization of the optimal management strategy is needed.

Ulnar Nerve Injury Following Distal Radius Fracture Assessed by Ultrasonography: Management of an Ulnar Nerve Lesion.

A fracture of the distal radius with an associated injury to the ulnar nerve is rare. The management of the ulnar nerve lesion is unclear. We present a patient with a closed distal radius fracture related to an injury to the ulnar nerve associated with diminished sensation and a claw deformity. This was assessed by ultrasonography (US) that showed the nerve to be in continuity without any evidence of compression. The nerve was deviated towards the volar side at the distal end of the ulna and was enlarged at the same point. Open reduction and internal fixation was performed for the fracture. Emergent nerve exploration was not performed. The function of the ulnar nerve was completely restored at 16 weeks after injury. In cases presenting with ulnar nerve injury, we recommend US to evaluate the condition of the ulnar nerve. Nerve exploration should be performed when neurological deficits were found on US or symptoms did not recover over 4 months observation. Level of Evidence: Level V (Therapeutic).

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.

Ulnar Neuritis and Its Affect on Outcomes of Elbow Ulnar Collateral Ligament Reconstruction.

BACKGROUND: No study has specifically evaluated how ulnar neuritis and ulnar nerve transposition affect outcomes in baseball players undergoing ulnar collateral ligament (UCL) reconstruction (UCLR). PURPOSE: To evaluate the effects of ulnar neuritis and ulnar nerve transposition in baseball pitchers undergoing UCLR in regard to return to sport, time to return to sport, and need for revision or additional surgery. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: At a single institution, all consecutive baseball pitchers undergoing UCLR between 2002 and 2015 were identified. Ulnar neuritis was diagnosed preoperatively by the following criteria: ulnar nerve symptoms, Tinel sign at the elbow, symptomatic subluxation, and numbness/paresthesia in an ulnar nerve distribution of the hand. The primary outcome of the study was return to sport. The secondary outcomes of the study were time to return to sport, length of playing career, and revision or additional surgery. RESULTS: A total of 578 UCLRs were performed in baseball players; of these, 500 UCLRs were performed in pitchers. Ulnar neuritis was diagnosed in 97 (19.4%) baseball pitchers presenting with UCL injury. There were no significant differences in patient characteristics or surgical techniques performed for reconstruction between baseball pitchers with and without ulnar neuritis. In review of injury characteristics, ulnar neuritis was significantly more likely to be diagnosed in pitchers with an acute onset of UCL injury (P = .03). Transposition of the ulnar nerve was more commonly performed in players with ulnar neuritis (47%) versus those without ulnar neuritis (10%; P = .0001). The players who had ulnar neuritis and underwent UCLR had a significantly lower odds of returning to sport (odds ratio, 0.45; P = .04); however, no significant difference was found for time to return to sport and length of playing career for those with and without ulnar neuritis (P = .38 and .51, respectively). CONCLUSION: The study suggests that ulnar neuritis, when present preoperatively in baseball pitchers undergoing UCLR, may adversely affect their ability to return to sport, whereas ulnar nerve transposition at the time of UCLR does not alter the ability to return to sport.

A case of ulnar nerve section at the elbow alleviated by Martin-Gruber communicating branch. Diagnostic characterization.

Martin-Gruber communicating branch may be a confounding factor in the diagnosis of ulnar neuropathy at the elbow. It may also lead to a surprising level of motor function conservation despite evident neuropathy. We present a patient with ulnar nerve section at the elbow who underwent early treatment by nerve suture. At 7 months, function was good, despite sonographic findings of neurotmesis at the elbow. Electroneurography revealed Martin-Gruber communicating branch. This type of communicating branch can be associated with functional conservation despite ulnar nerve section. Electrophysiological and ultrasound findings can be highly contributive in defining these conditions.

High-Resolution Ultrasound in the Diagnosis and Surgical Management of Ulnar Neuropathy at the Elbow.

High-resolution ultrasound (HRU) has recently demonstrated the potential to facilitate diagnosis and treatment of upper extremity compression neuropathy. The authors hypothesized that HRU can improve preoperative evaluation of ulnar neuropathy at the elbow (UNE) and that changes in ulnar nerve cross-sectional area (CSA) after cubital tunnel release may correlate with outcomes. Nineteen adult patients diagnosed with UNE who were scheduled for surgical decompression by a single hand surgeon were enrolled. Electrodiagnostic (EDX) testing, HRU of the ulnar nerve, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, and McGowan grade were obtained pre- and postoperatively. Fourteen patients completed the study. Statistically significant improvements were found in CSA measurements and QuickDASH scores. High-resolution ultra-sound was found to confirm UNE in all 7 patients with positive results on EDX, and additionally detected UNE in 3 of 6 patients with negative results on EDX and in 1 patient with equivocal (nonlocalized) EDX testing. All 4 of these additional HRU-detected cases improved clinically and by CSA measurements after surgery. In this series, HRU was superior to EDX testing in the diagnosis of UNE and demonstrated objective improvement in ulnar nerve CSA after successful cubital tunnel release. This modality, which is better tolerated, less costly, and less time-consuming than EDX testing or magnetic resonance imaging, should therefore be considered in the diagnosis and surgical management of UNE, particularly in cases with negative or equivocal results on EDX testing, or when outcomes are suboptimal. [Orthopedics. 2021;44(5):285-288.].

Influential factors of surgical decompression for ulnar nerve neuropathy in Guyon's canal.

BACKGROUND: Guyon's canal syndrome is nerve compressive pathology which can lead to sensory and/or motor function deficits. This problem is usually difficult to distinguish from cubital tunnel syndrome and relatively less common than cubital tunnel syndrome. This study evaluated the functional results and patient-reported outcomes following decompression of the ulnar nerve in Guyon's canal. METHODS: Patients who were diagnosed with Guyon's canal syndrome confirmed by electrodiagnostic studies and underwent nerve decompression surgery were included in this study. The functional improvement by examining the Froment's sign, Wartenberg's sign, static two-point discrimination, and Semmes Weinstein monofilament examination as physical examination scores was evaluated. The visual analogue scale of satisfaction and the disabilities of the arm, shoulder, and hand questionnaire were used for the postoperative patient-reported outcome evaluation. RESULTS: From 2003 to 2019, 38 cases had been enrolled with a mean age of 53 years, ranging from 19 to 85 years. There were seven patients with comorbidity of diabetes mellitus and 28 patients who received additional neurolysis combined with the Guyon's release procedure. There were 19 patients with a good response to surgery and 10 patients with a poor surgical outcome due to persistent paresthesia or weakness. After statistical analysis, it was revealed that several influential factors could have been related to a compromised functional outcome, including a symptom duration of more than 3 months, combination with additional neurolysis of ipsilateral extremity, and/or comorbidity with diabetes mellitus. CONCLUSION: It was concluded that promising functional outcomes after surgical release of ulnar neuropathy in Guyon's canal could be achieved if the patients did not need additional neurolysis or the symptom duration was within 3 months.

Outcomes and Complications of Tendon Transfers to Address Pinch and Grasp Weakness: A Systematic Review of the Operative Management of Ulnar Nerve Paralysis.

BACKGROUND: Patients with ulnar nerve paralysis note difficulties performing activities of daily living because of weakness of pinch and altered grasp mechanism. This review investigates outcomes of tendon transfers for ulnar nerve paralysis to assist in shared decision-making with patients during preoperative counseling and to inform operative choices. METHODS: A systematic review was conducted to identify studies reporting outcomes following tendon transfer for ulnar nerve palsy. Studies were screened according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and inclusion and exclusion criteria were applied. Primary outcome measures included postoperative pinch strength and mechanism of grasp. RESULTS: A total of 26 studies (687 patients) met criteria for inclusion. After pooled analysis, the flexor digitorum superficialis lasso procedure yielded the highest rate of complete correction of claw deformity (60.6 percent), followed by flexor digitorum superficialis four-tail operation (31.4 percent). The extensor carpi radialis longus four-tail operation yielded the greatest improvement in grip strength (3.8 kg). The extensor carpi radialis brevis four-tail operation resulted in the best open hand assessment and mechanism of closing scores; however, these studies did not objectively evaluate grip strength. The greatest increase in pinch strength was following tendon transfer to adductor pollicis alone. CONCLUSIONS: Despite the heterogeneous data, if the primary goal is improvement in the appearance of claw deformity, the evidence supports flexor digitorum superficialis lasso transfer. However, if the primary concern is grip strength, the data favor extensor carpi radialis longus four-tail transfer. When pinch strength is functionally limiting, adductorplasty alone is most effective. These data will assist providers in appropriately informing patients of common risks and complications and setting realistic expectations following tendon transfer procedures.

Myositis ossificans causing ulnar neuropathy: a case report.

Myositis ossificans (MO) can compress peripheral nerves and cause neuropathy. We herein describe a patient with ulnar neuropathy caused by MO at the medial elbow. A 28-year-old man with a drowsy mentality and multiple organ damage following a traffic accident was admitted to our hospital. After 3 weeks of postoperative care, the patient's mental status recovered. However, he complained of severe sharp pain in his left medial forearm and fourth and fifth fingers. He exhibited weak fifth finger abduction and wrist adduction. Severe elbow joint pain was elicited during range-of-motion testing of his left elbow. Ultrasound also showed an edematous, enlarged, hypoechoic ulnar nerve lying above the MO, and the MO outwardly displaced the ulnar nerve. Elbow radiographic examination, computed tomography, and magnetic resonance imaging revealed MO development and compression of the left ulnar nerve. The patient underwent surgery; the following day, his left medial forearm pain completely disappeared with slight improvement in the motor weakness of fifth finger abduction. Ultrasound is a useful tool to easily evaluate the presence of MO and compression of peripheral nerves caused by MO.