The value of the plate mechanical properties in a case of thoracoplasty at the congenital pectus excavatum

Surgical treatment of a congenital pectus excavatum (CPE) includes using of a plate that holds the correct anatomical shape of the chest for a long time. Before implanting the plate behind a sternum, it is bent so that after correcting the deformation, it reproduces shape of the ribs on both sides and fits close to them. Displacement and rotation are the most frequent complications after plate implantation. Therefore, mechanical properties of the plate, such as: strength, ability to withstand the load during surgery and in the long term period — is one of the main guarantees to obtain the good result. Objective. To study the mechanical properties of the plate which is used for thoracoplasty at CPE under conditions comparable to real loads in order to gain maximal correction. Methods. Experimental bending tests were performed on 5 standard plates of 2.5 mm thick, 13 mm width and 200 mm length, made from titanium Ti6–AL4–V (according to ISO 5832-3). All plates were bent with a special surgical instrument according to the anatomical shape of a chest, using method of surgery by D. Nuss. All plates supports were placed on a distance from the fixing screws. The force of bending load was applied to the middle of the plate, gradually increasing from 150 to 600 H with a step 50 H. At each value of the loading we measured the height of the plate edge elevation. Results. Under load conditions of 600 H, the elevation of a plate edge did not exceed 3 mm and was equal to (2700 ± 177) μcm. In a case of twice lower loads (300 H), value of lifting edge of the plate decreased in three times and was (700 ± 85) μcm. Changes that happened under loading were the same for all five types of the plate. Conclusions. It is proved that the plates can fully withstand corrective loads with a minimal deformation after thoracoplasty. The discrepancy bet­ween the plate shape in the lateral parts to the restored thorax is caused by the changing of configuration of the last one and increasing in the anteroposterior size. Key words. Plate, mechanical pro­perties, thoracoplasty.

TINJAUAN ESTETIKA TARI PIRIANG JORONG LIMAU SUNDAI PASIR TALANG SOLOK SELATAN

This article aims to reveal esthetic values embodied in the traditional plate dance from Jorong Limau Sundai, Pasir Talang Village, South Solok Regency. The dance isspecially performed by women. This qualitative research used descriptive method. Theobject of this study is the structure of performance of the plate dance from Jorong LimauSundai. The researcher is the key instrument in this study. Data was collected byobserving, interviewing, and documentation study. Data was then analysed usingethnographic method. The research found that this dance has traditional esthetics based on local culturalvalues of the Jorong Limau Sundai community. The esthetic values are reflected in themovement structure, costume, floor design, music design, dance technique, and facialexpression of the dancers who are mostly women aged 45 to 48 years old. The estheticvalues of this dance derive from tradition that based in daily values of Jorong LimauSundai community. Key words: Plate Dance Of Jorong Limau Sundai, Esthetic Values, Dan DancePerformance Abstrak Artikel ini bertujuan untuk mengungkapkan nilai estetika yang terkandung dalamstruktur penyajian tari Piriang tradisional dari Jorong limau Sundai Pasir TalangKabupaten Solok Selatan. Tari ini khasnya ditarikan oleh penari perempuan. Penelitianini adalah penelitian kualitatif dengan metode deskriptif. Objek penelitaian adalahstruktur penyajian tari Piriang tradisional Jorong Limau Sundai. Peneliti merupakaninstrumen kunci dalam penelitian ini. Teknik pengumpulan data melalui pengamatanlangsung, wawancara, dan studi pustaka serta pendokumentasian. Data dianalisisdengan metode etnografi. Berdasarkan hasil penelitian bahwa tari ini memiliki estetika tradisional yangberakar pada nilai-nilai budaya lokal masyarakat Jorong Limau Sundai. Nilai estetikapada tari Piriang Jorong Limau Sundai terdapat pada struktur gerak, kostum, disainlantai, disain musik, dan teknik tari serta ekspresi dari penari perempuan yang rata-rataberusia 45 sampai 48 tahun. Nilai estetika tari Piriang Jorong Limau Sundai tidakterlepas dari nilai budaya yang menjadi dasar bagi masyarakat Jorong Limau Sundaidalam kehidupan sehari-harinya. Kata kunci: Tari Piriang Jorong Limau Sundai, nilai estetika dan penyajian tari