Although the term articularis cubiti muscle is incorporated in the official anatomical nomenclature, only sparse data about its appearance are available. It is usually described as few fibres originating from the medial head of the triceps brachii muscle and inserting to the capsule of the elbow joint. However, the most recent observations regarding the morphological relations in the posterior elbow region point towards the absence of a well-defined muscle. Therefore, this study was designed to verify the existence of the articularis cubiti muscle in question and to compile more data on the topographical features of the subtricipital area near the posterior aspect of the elbow. To address these questions, 20 embalmed upper limbs were dissected, and seven samples were collected for histological analysis. The laboratory findings were then correlated with 20 magnetic resonance imaging (MRI) scans of the elbow. Consequently, a narrative review of literature was performed to gain more information on the discussed muscle in a historical context. Upon the anatomical dissection, muscular fibres running from the posterior aspect of the shaft of the humerus to the elbow joint capsule and olecranon were identified in 100% of cases. Histologically, the connection with the joint capsule was provided via winding bands of connective tissue. On MRIs, the muscular fibres resembled a well-demarcated thin muscle located underneath the medial head of the triceps brachii muscle. Combined with the review of literature, we concluded that the constant articularis cubiti muscle originates from the posterior shaft of the humerus and attaches indirectly to the posterior aspect of the elbow joint capsule and directly to the superior portion of the olecranon. The obtained results slightly differ from the modern description, but are in agreement with the original publication, which has become misinterpreted throughout time. Presumably, the misused description has led to questioning the existence of an independent muscle. Moreover, our findings attribute to the articularis cubiti muscle, a function in pulling on the posterior aspect of the elbow joint capsule to prevent its entrapment, and possibly also a minor role in extension of the forearm. The presented results should be taken into consideration when intervening with the posterior aspect of the elbow joint because the articularis cubiti muscle poses a consistently appearing landmark.
Transscleral diffusion delivery of chemotherapy is a promising way to reach the vitreal seeds of retinoblastoma, the most common intraocular malignancy in childhood. In this in vivo study, the delivery of topotecan via lens-shaped, bi-layered hydrogel implants was combined with transconjunctival cryotherapy to assess whether cryotherapy leads to higher concentrations of topotecan in the vitreous. The study included 18 New Zealand albino rabbits; nine rabbits received a topotecan-loaded implant episclerally and another nine rabbits received transconjunctival cryotherapy superotemporally 2 weeks before implant administration. Median vitreous total topotecan exposures (area under the curve, AUC) were 455 ng·h/mL for the cryotherapy group and 281 ng·h/mL for the non-cryotherapy group, and were significantly higher in the cryotherapy group, similar to maximum levels. Median plasma AUC were 50 ng·h/mL and 34 ng·h/mL for the cryotherapy and non-cryotherapy groups, respectively, with no statistically significant differences between them. In both groups, AUC values in the vitreous were significantly higher than in plasma, with plasma exposure at only approximately 11-12% of the level of vitreous exposure. The results confirmed the important role of the choroidal vessels in the pharmacokinetics of topotecan during transscleral administration and showed a positive effect of cryotherapy on intravitreal penetration, resulting in a significantly higher total exposure in the vitreous.
- Publikační typ
- časopisecké články MeSH
