ABSTRACT
BACKGROUND: This study compared the clinical results for nonporous stems vs. trabecular metal (TM) stems used in reverse shoulder arthroplasty (RSA) for comminuted proximal humeral fractures (CPHFs) in elderly patients. METHODS: In this retrospective study, a total of 41 shoulders (39 women) of patients with CPHF aged >70 years who underwent RSA were investigated. The minimum follow-up period was 2 years. A total of 15 shoulders were treated with Grammont-style RSA using nonporous stems (the G-RSA group), and 26 shoulders were treated with RSA combining TM stems (the FR-RSA group). The American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score, shoulder joint range of motion (ROM), and radiographic findings were compared between the 2 groups. RESULTS: ASES scores and Constant scores were significantly higher in the FR-RSA group than in the G-RSA group. External rotation at the side in the FR-RSA group was significantly higher than that in the G-RSA group. In the FR-RSA and G-RSA groups, the union rates at the greater tuberosity (GT) were 88.5% and 46.7%, respectively, and scapular notching rates were 20% and 7.7%, respectively. Based on a subanalysis, the age was lower, body mass index was higher, and ASES scores, Constant scores, and external rotation ROM were higher in the GT union group than in the GT nonunion group. CONCLUSION: GT bone union rates were high, and external rotation ROM of the shoulder joint were more improved for RSA using TM stems than those for RSA using nonporous stems in elderly patients with CPHF.
ABSTRACT
During the loosening cascade of cemented rough femoral stems, the destruction of the mantle and the production of cement and metal wear debris occur after the loss of constraint at the interface. Two-dimensional (2D) measurements (light microscopy based morphometry on fragments of mantles and vertical scanning interferometry of femoral stems) permitted mathematical 3D-extrapolations to estimate the wear volumes. Fragments of the cement mantles available lost volumes from 0.85 mm(3) to 494.10 mm(3) (median amount of bone cement wear = 178,426 mg). The harder metal surfaces lost between 1.459 mm(3) and 5.688 mm(3) of material (the median amount of metal wear per surface = 1.504 mg/100 mm(2)). Compared to the loss of material due to the fretting of stems, the abrasion of metal, and cement in defective cement mantles produced wear volumes sufficiently high to induce osteolysis. Though the design of the femoral stem and the handling of bone cement do not represent contemporary design and clinical practice, respectively, an extremely high number of joint replacements still in daily use may be impacted by this study because of possible predicted failures. Once the processes of fragmentation, abrasion, and osteolysis have been realized, the time until revision surgery should not be unduly prolonged.
Subject(s)
Arthroplasty, Replacement, Hip , Bone Cements/adverse effects , Hip Prosthesis/adverse effects , Medical Device Recalls , Osteolysis/pathology , Polymethyl Methacrylate/adverse effects , Prosthesis Failure , Aged , Aged, 80 and over , Equipment Failure Analysis , Humans , Male , Middle Aged , Osteolysis/etiologyABSTRACT
Pontas diamantadas são instrumentos rotatórios abrasivos de uso rotineiro na prática clínica odontológica, com macrogeometria constituída de haste metálica, ponta ativa e eixo Intermediá- rio. Objetivo: avaliar as dimensões padrões dos componentes que constituem a macrogeometria das pontas diamantadas. Material e Método: a fim de padronização, considerou-se como ponta ativa a região do instrumental que possui granulação; como eixo Intermediário a região compreendida entre a primeira depressão presente na base até o início da ponta ativa; e como haste metálica toda região localizada entre a base da ponta diamantada até a primeira depressão. Realizou os testes com seis marcas comerciais: KG Sorensen, Option, Vortex, Microdont, Zeep e Fava. Foram selecionadas 120 pontas diamantadas tronco-cônicas, modelos 2200 (n=10) e 2135 (n=10). O diâmetro e comprimento foram analisados em sete regiões correspondentes à macrogeometria. O diâmetro do orifício de encaixe de pontas diamantadas em turbinas de alta rotação de cinco marcas (Gnatus, Kavo, Calu, Dx e Dabi) também foi mensurado. Para realizar as medidas, paquímetro digital (Mitutoyo, modelo número 6, C-B) foi utilizado por um único operador calibrado. Resultado: as dimensões de ambos os modelos de pontas diamantadas apresentaram variação, quando comparado os fabricantes, seja no comprimento total da haste metálica, eixo intermediário ou ponta ativa. A marca comercial KG Sorensen apresentou baixa alteração na dimensão entre seus instrumentos. Conclusão: a não padronização das pontas diamantadas pode prejudicar a confecção de preparos e também o aprendizado de estudantes de odontologia.
Diamond burs are abrasive rotary instrumental routinely used in clinical dentistry practice with macro geometry consists of metal stem, the active tip and intermediate shaft. Objective: evaluate the standardized dimensions of the components that constitute the macro geometry of the diamond bur. Methods: in order to standardize, it was considered as active tip the area of the diamond bur that has granulation; as intermediate the region between the first depression at the base until the beginning of the active tip; and as stem all region located between the base of the diamond tip to the first depression. The test was performed with six brand: KG Sorensen, Option, Microdont, FAVA, Zeep, Vortex. 120 trunk-conical diamond burs, models 2200 (n = 10) and 2135 (n = 10) were selected. The diameter and length were evaluated in seven regions corresponding to macro geometry. The diameter of the diamond bur orifice fitting on the high speed turbines of five brands (Gnatus, Kavo, Calu, Dx and Dabi) were also measured. A digital caliper (Mitutoyo, modelo número 6, C-B) was used for measurements by a single calibrated operator. Results: the dimensions of both models showed variation compared trademarks, either in the total length of the metal stem, active tip or intermediary. KG Sorensen trademark presented low alterations in size between their instruments. Conclusion: the non-standardized of diamond burs can hamper the confection of preparations and also the learning of dental students.
