Aims. Medial humeral epicondyle fractures (MHEFs) are common elbow fractures in children. Open reduction should be performed in patients with MHEF who have entrapped intra-articular fragments as well as displacement. However, following open reduction, transposition of the ulnar nerve is disputed. The aim of this study is to evaluate the need for ulnar nerve exploration and transposition. Methods. This was a retrospective cohort study. The clinical data of patients who underwent surgical treatment of MHEF in our hospital from January 2015 to January 2022 were collected. The patients were allocated to either transposition or non-transposition groups. Data for sex, age, cause of fracture, duration of follow-up, Papavasiliou and Crawford classification, injury-to-surgery time, preoperative ulnar nerve symptoms, intraoperative exploration of ulnar nerve injury, surgical incision length, intraoperative blood loss, postoperative ulnar nerve symptoms, complications, persistent ulnar neuropathy, and elbow joint function were analyzed. Binary logistic regression analysis was used for statistical analysis. Results. A total of 124 patients were followed up, 50 in the ulnar nerve transposition group and 74 in the non-transposition group. There were significant differences in ulnar nerve injury (p = 0.009), incision length (p < 0.001), and blood loss (p = 0.003) between the two groups. Binary logistic regression analysis revealed that preoperative ulnar nerve symptoms (p = 0.012) were risk factors for postoperative ulnar nerve symptoms. In addition, ulnar nerve transposition did not affect the occurrence of postoperative ulnar nerve symptoms (p = 0.468). Conclusion. Ulnar nerve transposition did not improve clinical outcomes. It is recommended that the ulnar nerve should not be transposed when treating MHEF operatively. Cite this article: Bone Joint J 2024;106-B(2):212–218

We evaluated the morphological changes to the ulnar nerve of both elbows in the cubital tunnel by sonography in a total of 237 children, of whom 117 were aged between six and seven years, 66 between eight and nine years, and 54 between ten and 11 years. We first scanned longitudinally in the extended elbow and then transversely at the medial epicondyle with the elbow extended to 0°. We repeated the scans with the elbow flexed at 45°, 90°, and 120°. There were no significant differences in the area of the ulnar nerve, but the diameter increased as the elbow moved from extension to flexion in all groups. More importantly, the ulnar nerve was subluxated anteriorly on to the medial epicondyle by 1.5% to 1.9% in extended elbows, by 5.9% to 7.9% in those flexed to 45°, by 40.0% to 44% in those flexed to 90°, and by 57.4% to 58.1% in those flexed to 120°, depending on the age group. Sonography clearly and accurately showed the ulnar nerve and was useful for localising the nerve before placing a medial pin. Because the ulnar nerve may translate anteriorly onto the medial epicondyle when the elbow is flexed to 90° or more, it should never be overlooked during percutaneous medial pinning

We conducted an anatomical study to determine the best technique for transfer of the anterior interosseous nerve (AIN) for the treatment of proximal ulnar nerve injuries. The AIN, ulnar nerve, and associated branches were dissected in 24 cadaver arms. The number of branches of the AIN and length available for transfer were measured. The nerve was divided just proximal to its termination in pronator quadratus and transferred to the ulnar nerve through the shortest available route. Separation of the deep and superficial branches of the ulnar nerve by blunt dissection alone, was also assessed. The mean number of AIN branches was 4.8 (3 to 8) and the mean length of the nerve available for transfer was 72 mm (41 to 106). The transferred nerve reached the ulnar nerve most distally when placed dorsal to flexor digitorum profundus (FDP). We therefore conclude that the AIN should be passed dorsal to FDP, and that the deep and superficial branches of the ulnar nerve require approximately 30 mm of blunt dissection and 20 mm of sharp dissection from the point of bifurcation to the site of the anastomosis. The use of this technique for transfer of the AIN should improve the outcome for patients with proximal ulnar nerve injuries. Cite this article: Bone Joint J 2014;96-B:789–94

The transfer of part of the ulnar nerve to the musculocutaneous nerve, first described by Oberlin, can restore flexion of the elbow following brachial plexus injury. In this study we evaluated the additional benefits and effectiveness of quantitative electrodiagnosis to select a donor fascicle. Eight patients who had undergone transfer of a simple fascicle of the ulnar nerve to the motor branch of the musculocutaneous nerve were evaluated. In two early patients electrodiagnosis had not been used. In the remaining six patients, however, all fascicles of the ulnar nerve were separated and electrodiagnosis was performed after stimulation with a commercially available electromyographic system. In these procedures, recording electrodes were placed in flexor carpi ulnaris and the first dorsal interosseous. A single fascicle in the flexor carpi ulnaris in which a high amplitude had been recorded was selected as a donor and transferred to the musculocutaneous nerve. In the two patients who had not undergone electrodiagnosis, the recovery of biceps proved insufficient for normal use. Conversely, in the six patients in whom quantitative electrodiagnosis was used, elbow flexion recovered to an M4 level. Quantitative intra-operative electrodiagnosis is an effective method of selecting a favourable donor fascicle during the Oberlin procedure. Moreover, fascicles showing a high-amplitude in reading flexor carpi ulnaris are donor nerves that can restore normal elbow flexion without intrinsic loss

1. A case of compression of the deep branch of the ulnar nerve is described. 2. Anatomical evidence is presented that the reason for the special liability of the deep branch to be compressed by ganglia in this region is its relationship to a ligamentous band which passes from the pisiform bone to the hamate superficial to the deep branch of the ulnar nerve. 3. This band, though constant, has not been well recognised

1. Three cases of Colles's fracture complicated by ulnar nerve paralysis are described. 2. Observation at operation in two cases and studies in a cadaver demonstrated a close relationship of the ulnar nerve to a fracture line at the lower end of the radius when the distal fragment is displaced dorsally and radially. It is surprising that this injury has not been observed and commented on previously

Twenty-two patients with ulnar nerve palsy at the elbow, confirmed by electromyography, were treated by a night splint which prevented flexion of the elbow beyond 60 degrees. The splint was worn all night regularly for at least six months. At a mean follow-up of 11.3 months, 17 patients had clinical and electromyographic assessment and five were contacted by telephone. There was improvement in the symptoms in every patient, including three who had failed to respond to surgical decompression. There was electromyographic improvement in 16 of the 17 patients re-examined at follow-up. The mean improvement in motor nerve conduction velocity was 6.5 m/s and in sensory nerve conduction velocity 9.5 m/s. The efficacy of this treatment suggests that nocturnal elbow flexion is an important cause of ulnar nerve lesions at the elbow

1. A case of compression of the deep palmar branch of the ulnar nerve by an accessory abductor minimi digiti muscle is described. 2. The morphology of abnormal muscles in the hypothenar region is discussed. 3. Five previously reported cases of ulnar nerve compression at the wrist by an anomalous muscle are reviewed. 4. When symptoms are produced by an anomalous hypothenar muscle, they seem to be related to the anatomical site of the muscle and the presence of muscle hypertrophy. Occupational factors may be important in producing this hypertrophy

Outcome studies of revision surgical treatment for recurrent or persistent neuropathy of the ulnar nerve at the elbow are relatively rare and none involves patient self-assessment. In this study of 40 patients (41 elbows), a clear discrepancy is shown between clinical assessment and the patient’s own view. From clinical assessment, 20% of patients had an excellent result, whereas only one (2.5%) patient self-reported a complete cure. More reports using patient self-assessment and validated scores are required

1. A case of ulnar nerve compression at the wrist caused by rheumatoid arthritis producing motor and sensory changes is presented. 2. The diagnosis from compression at the elbow can be determined by electromyography. 3. It may be that lesions of the deep branch leading to motor changes only occur in rheumatoid arthritis more often than is suspected, their effects being hidden by the concomitant disease and its associated muscle wasting

1. Sixty-one cases of compression of the ulnar nerve are reported, forty at the elbow and twenty-one at the wrist. Although contributory factors may include deformity, osteoarthritis, injury, ganglia and other tumours, the narrow anatomical confines of the nerve at these two levels are noteworthy and alone may produce nerve compression. 2. Careful clinical examination will usually determine the level of involvement if not the exact pathology. Surgical exploration is indicated both as a diagnostic and therapeutic procedure in most cases. 3. Following removal of the compressing agent rapid recovery occurred in most cases

Ulnar nerve function, during and after open reduction and internal fixation of fractures of the distal humerus with subperiosteal elevation of the nerve, was assessed by intra-operative neurophysiological monitoring. Intermittent recording of the compound muscle action potentials was taken from the hypothenar muscles in 18 neurologically asymptomatic patients. The mean amplitude of the compound muscle action potential after surgery was 98.1% (. sd. 17.6; −37% to +25%). The amplitude improved in six patients following surgery. Despite unremarkable recordings one patient had progressive paresis. Motor impairment is unlikely if the compound muscle action potential is continuously preserved and not reduced by more than 40% at the end of surgery. Temporary decreases in amplitude by up to 70% were tolerated without clinical consequences. However, repeated clinical examination is obligatory to recognise and treat early post-operative palsy

Traumatic neuritis of the deep branch of the ulnar nerve may be caused by compression of the nerve by a ganglion originating in a carpal joint, and removal of the protrusion is followed by a prompt recovery. This lesion was found in four out of five explorations

1. The progress of recovery after transposition of the ulnar nerve has been studied in forty-six patients with ulnar neuritis of traumatic or mechanical origin. 2. In assessing the results, the lesions were divided into three grades according to the severity of the neurological signs: Grade I, minimal lesions with no detectable motor weakness; Grade II, intermediate lesions; Grade III, severe lesions with paralysis of one or more of the ulnar intrinsic muscles. 3. The earliest and most constant result after operation was the relief of discomfort and ulnar paraesthesiae. 4. The degree of motor recovery varied according to the severity of the lesion at the time of the operation. In Grades I and II cases, all the muscles (with one exception) were acting against gravity and resistance at the final examination. In Grade III cases, the recovery was usually far from complete. Recovery of sensibility was uniformly good. 5. In a further six patients with persistent symptoms after transposition, relief was obtained by free mobilisation and placing the nerve deep to the flexor origin

Ulnar neuropathy presents as a complication in 5% to 10% of total elbow replacements, but subsequent ulnar neurolysis is rarely performed. Little information is available on the surgical management of persistent ulnar neuropathy after elbow replacement. We describe our experience with the surgical management of this problem.

Of 1607 total elbow replacements performed at our institution between January 1969 and December 2004, eight patients (0.5%) had a further operation for persistent or progressive ulnar neuropathy. At a mean follow-up of 9.2 years (3.1 to 21.7) six were clinically improved and satisfied with their outcome, although, only four had complete recovery. When transposition was performed on a previously untransposed nerve the rate of recovery was 75%, but this was reduced to 25% if the nerve had been transposed at the time of the replacement.