Clarification of Eponymous Anatomical Terminology: Structures Named After Dr Geoffrey V. Osborne That Compress the Ulnar Nerve at the Elbow

A History of Anatomical Eponyms of the Ulnar Nerve

The ulnar nerve has a long and often misunderstood history with eponym usage. We describe the history of eponym usage in the anatomy of the ulnar nerve-who, when, what, where, and how. The relevant anatomy is investigated from proximal to distal, from the Arcade of Struthers to Osborne's band, to forearm ulnar nerve to median nerve connections, to Guyon's canal. We hope to provide a historical perspective of interest, resolve any controversies in semantic definitions, and create a comprehensive library of eponymous terms related to ulnar nerve anatomy.

Morphological Changes of Medial Epicondyle-Olecranon Ligament and Ulnar Nerve in the Cubital Tunnel Syndrome: An Ultrasonic Study

Objective

Few studies have performed detailed ultrasound measurements of medial epicondyle‐olecranon (MEO) ligament that cause the entrapment of ulnar nerve. This study aims to comprehensively evaluate dynamic ultrasonographic characteristics of MEO ligament and ulnar nerve for clinical diagnosis and accurate treatment of cubital tunnel syndrome (CuTS).

Methods

Thirty CuTS patients (CuTS group) and sixteen healthy volunteers (control group) who underwent ultrasound scanning from October 2016 to October 2020 were retrospectively collected, with 30 elbows in each group. Primary outcomes were thickness at six points, length and width of MEO ligament. Secondary outcomes were thickness of ulnar nerve under MEO ligament at seven parts and the cross‐sectional area (CSA) of ulnar nerve at proximal end of MEO ligament (P_0 mm). The thickness of MEO ligament and ulnar nerve in different points of each group was compared by one‐way ANOVA analysis with Bonferroni post hoc test, other outcomes were compared between two elbow positions or two groups using independent‐samples t test.

Results

Thickness of MEO ligament in CuTS group at epicondyle end, midpoint in transverse view, olecranon end, proximal end, midpoint in axial view, and distal end was 0.67 ± 0.31, 0.37 ± 0.18, 0.89 ± 0.35, 0.39 ± 0.21, 0.51 ± 0.38, 0.36 ± 0.25 at elbow extension, 0.68 ± 0.34, 0.38 ± 0.27, 0.77 ± 0.39, 0.32 ± 0.20, 0.48 ± 0.22, 0.32 ± 0.12 (mm) at elbow flexion, respectively. Compared with control group, they were significantly thickened except for proximal end at elbow flexion. MEO ligament thickness at epicondyle end and olecranon end was significantly larger than midpoint in two groups. No significant difference was found in length and width of MEO ligament among different comparisons. Ulnar nerve thickness at 5 mm proximal to MEO ligament (P_5 mm, 3.25 ± 0.66 mm) was significantly increased than midpoint of MEO ligament (Mid), distal end of MEO ligament (D_0 mm), 5 mm (D_5 mm), 10 mm (D_10 mm) distal to MEO ligament at extension in CuTS group. Compared with control group, ulnar nerve thickness at P_5 mm in CuTS group was significantly increased at extension position, at D_5 mm and D_10 mm was significantly decreased at flexion position. CSA of ulnar nerve at extension position (14.44 ± 4.65 mm²) was significantly larger than flexion position (11.83 ± 3.66 mm²) in CuTS group, and CuTS group was significantly larger than control group at two positions.

Conclusions

MEO ligament in CuTS patients was thickened, which compressed ulnar nerve and caused its proximal end swelling. Ultrasonic image of MEO ligament thickness was a significant indicator for CuTS and can guide surgeons in selecting the appropriate treatment.

Possible points of compression of the ulnar nerve: Tricks and traps that await clinicians from an anatomical point of view

The ulnar nerve can be subject to numerous types of compression. The most common are cubital tunnel and ulnar tunnel syndromes, but there are many others with more uncommon etiologies. The existence of additional communicating branches, median nerve involvement, various types of injuries, and unusual anatomical variations can be a challenge for both diagnosis and treatment. This review presents a comprehensive depiction of ulnar nerve entrapment syndromes with particular reference to their anatomical background, risk factors, and clinical evaluation. Even common disorders can result from atypical morphological changes. It is important to be familiar with them as it is a key ability in daily medical practice.

The prevalence of anconeus epitrochlearis muscle and Osborne's ligament in cubital tunnel syndrome patients and healthy individuals: An anatomical study with meta-analysis

BACKGROUND

Anconeus epitrochlaeris muscle and Osborne's ligament are anatomical variants that are occasionally found at the cubital tunnel of the elbow. In certain individuals, these two structures may compress the ulnar nerve resulting in a cubital tunnel syndrome. Although these variants have been reported extensively, its prevalence is still unclear and its contribution to cubital tunnel syndrome is debatable. The aim of this study is to generate weighted frequency values of the anconeus epitrochlearis and Osborne's ligament, as well as to identify any association of these two structures with gender, side, ethnicity and the development of cubital tunnel syndrome.

METHODS

An anatomical study and a meta-analysis were performed to more accurately study the prevalence of anconeus epitrochlearis and Osborne's ligament. A total of 40 original studies including the present study met the inclusion criteria for meta-analysis and 6 case reports for descriptive analysis.

RESULTS

Crude pooled prevalence estimate of the anconeus epitrochlearis was significantly higher (p < 0.001) in healthy subjects (14.2%) than in subjects diagnosed with cubital tunnel syndrome (4.5%). No significant difference was found for gender, side or laterality. The anconeus epitrochlearis was significantly more common in Europeans populations (18.2%) when compared with North American (6.8%) (p = 0.012) and Asian populations (7.5%) (p < 0.001). Anconeus epitrochlearis had a tendency to be hypertrophied when associated with cubital tunnel syndrome. The definition of Osborne's ligament is unclear, resulting in inconsistent reported prevalence across studies.

CONCLUSION

The present study provides a more accurate estimate of anconeus epitrochlearis across the populations. There was a negative correlation between the presence of anconeus epitrochlearis and the development cubital tunnel syndrome, supporting the idea that the muscle may be protective against cubital tunnel syndrome. Future studies are needed to give proper definition of Osborne's ligament and accurately study its prevalence across populations.

Ulnar nerve subluxation and dislocation: a review of the literature

The pathogenesis of ulnar nerve subluxation and dislocation is widely debated. Upon elbow flexion, the ulnar nerve slips out of the groove for the ulnar nerve, relocates medial or anterior to the medial epicondyle, and returns to its correct anatomical position upon extension. This chronic condition can cause neuritis or neuropathy; however, it has also been suggested that it protects against neuropathy by reducing tension along the nerve. This article reviews the extant literature with the aim of bringing knowledge of the topic into perspective and standardizing terminology.

In idiopathic cubital tunnel syndrome, ulnar nerve excursion and instability can be reduced by repairing Osborne's ligament after simple decompression

Osborne's modified decompression involves repairing Osborne's ligament beneath the ulnar nerve after simple decompression for idiopathic cubital tunnel syndrome. In this retrospective interrupted time series, 31 patients underwent modified simple decompression and 20 patients underwent conventional simple decompression. In the modified simple decompression group, the ulnar nerve length was measured at operation in full elbow flexion and extension before and after repair of Osborne's ligament. Ulnar nerve instability during elbow motion was measured using ultrasonography before operation and at 12 months after operation. In patients treated by modified simple decompression, the ulnar nerve length in full elbow flexion reduced significantly after repair of Osborne's ligament. At 12 months after surgery, the grade of ulnar nerve instability was lower in the modified simple decompression group than in the conventional simple decompression group. The clinical outcomes did not differ significantly between the groups at 24 months after operation. Level of evidence: III.

A Review of the Theoretical Fascial Models: Biotensegrity, Fascintegrity, and Myofascial Chains

The fascial tissue includes solid and liquid fascia (body fluids such as blood and lymph). The fascia's nomenclature is the subject of debate in the academic world, as it is classified starting from different scientific perspectives. This disagreement is not a brake but is, in reality, the real wealth of research, the multidisciplinarity of thought and knowledge that leads to a deeper understanding of the topic. Another topic of discussion is the fascial model to conceptualize the human body, that is, how the fascial tissue fits into the living. Currently, there are some models: biotensegrity, fascintegrity, and myofascial chains. Biotensegrity is a mechanical model, which takes into consideration the solid fascia; fascintegrity considers the solid and the liquid fascia. Myofascial chains converge attention on the movement and transmission of force in the muscle continuum. The article is a reflection on fascial models and how these are theoretical-scientific visions that need to be further investigated.