Browsing by Author "Wijesooriya, P."

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Anomalies of the Lumbrical Muscles of the Hand
(University of Kelaniya, 2012) Ranaweera, L.; Hasan, R.; Salgado, S.; Karunanayake, A.; Salvin, K.A.; Fernando, P.; Fernando, E.; Wijesooriya, P.; Vithanage, S.
Introduction:The human hand occupies a unique position in evolution. The lumbrical muscles, one of the major constituents of intrinsic musculature in hand, play significantly greater role in the precision movements of the fingers. There are four cylindrical lumbrical muscles which rise from the four tendons of flexor digitorumprofundus (FDP) in the hand and pass along the radial side of the corresponding metacarpophalangeal joint to insert into the dorsal digital expansion of the medial four fingers. The first and second lumbricals are unipennate while the third and fourth lumbricals are bipennate. Anomalies of the attachments of the lumbricals are not uncommon and have a significant value in the design of surgical procedures. Objectives: To study the possible variations of lumbrical muscles and also document a relevant Sri Lankan study. Methodology:This research was carried out as a descriptive study in19 preserved human hands in the Departments of Anatomy, University of Kelaniya, Ragama. Results: In 9 (47.4%) hands the lumbricals were normal. Regarding the proximal attachments, the third lumbrial was unipennate in 3 (15.7%) whereas same architecture for the fourth lumbrical encountered was 2 (10.5%). Moreover, it was found that 1 (5.3%) of the second lumbricals was bipennate. Regarding the distal attachments, the split insertion of the third lumbrial and fourth lumbrical were observed as 2 (10.5%) and 1 (5.3%), respectively. Interestingly, 1 (5.3%) of the third lumbricals was inserted on the medial side of the middle finger. Conclusion: In our preliminary studyof lumbrical muscles of the hand, it was apparent that majority of the observations are comparable to previous research, while there were a higher percentage of proximal attachment variations than distal attachment variations in the study group.
Morphological variations of lumbrical muscles in Sri Lankan cadavers
(IMED Research Publications, 2022) Ranaweera, L.; Wijesooriya, P.; Vithanage, S.; Cabral, E.
Introduction: Lumbricals are the small, worm-like, intrinsic muscles responsible for performing the precision pinch movements of the hand. These are quite unique in their position owing to movable proximal and distal tendon attachments. Purpose of the study: The aim of the study was to identify anomalies of lumbrical muscle present in the Sri Lankan people. Materials and Methods: A sample of 39 formalin preserved cadaveric human hands were subjected to the gross morphological study. Results: It was encountered that 59% of the lumbricals were normal in proximal and distal attachments whereas the rest of the lumbicals (41%) indicated the morphological variations. Among the hands, unipennate third lumbrical was seen in 7.7% (Left-15.7%: Right 0%) and unipennate fourth lumbrical was seen in 5.1% (Left-10.5%: Right 0%). The bipennate second lumbrical was seen in 5.1% (Left 5.3%: Right 5.1%). The 10.3% of split insertion was encountered in third lumbricals (Left 10.5%: Right 10%) as well as in fourth lumbricals (Left 5.3%: Right 15%). The third lumbrical insertion on the medial side of the middle finger was seen in 2.5% (Left 5.3%: Right 0%). Conclusion: The left hand is having more lumbrical variations than the right hand of the subjected human cadavers. The most common variation site is the insertion site. The variants are numerous in third and fourth lumbricals. The most common type of variation is the split insertion.
Variations in the Termination of the Human Thoracic Duct
(University of Kelaniya, 2012) Hasan, R.; Salgado, S.; Karunanayake, A.; Salvin, K.A.; Fernando, P.; Ranaweera, L.; Vithanage, S.; Wijesooriya, P.; Ilayperuma, I.; Fernando, E.
Introduction: The mammalian thoracic duct is the main lymphatic channel which drains lymph from the distal extremities of the trunk, lower limbs and the left half of the proximal trunk. In humans, it runs a typical course commencing over the twelfth thoracic vertebra and ascends through the aortic orifice of the diaphragm. It inclines to the left at the level of the Sternal angle and terminates by draining into the left jugulosubclavian junction. Objectives: Variations from this typical course are not uncommon and have been the subject of extensive research. Knowledge of the possible variations in the thoracic duct would enable accurate thoraco- cervical surgery, thus preventing inadvertent damage to the thoracic duct and consequent leakage of chyle.This research is carried out with the aim ofenhancing the existing knowledge of the possible variations of termination of the human thoracic duct while also documenting a relevant Sri Lankan study. Methodology: This research was carried out as a descriptive study in36 preserved human cadavers in the Departments of Anatomy, the University of Kelaniya and the University of Ruhuna. Results: In 22 (61.11%) cadavers the thoracic duct drained into the left jugulosubclavian junction whereas in 11 (30.56%) cadavers it drained into the left subclavian vein. Moreover, in 2(5.56%) cadavers it drained into the left internal jugular vein. Interestingly, in 1 (2.77%) cadaver thoracic duct drained into both left subclavian vein and jugulosubclavian junction through the presence of a bifurcation. Conclusion: It was apparent that majority of the findings are comparable to previous research, while there were variations in the percentage incidence of the findings.