Principle of Lag-Screw Fixation in Mandibular Trauma

Prevalence of surgical site infections after open reduction and internal fixation for mandibular fractures: a systematic review and meta-analysis

Our study aims to estimate the prevalence of surgical site infections (SSI) following open reduction and internal fixation (ORIF) for mandibular fractures and to determine the effect of potential moderators on it. A systematic literature search (Medline and Scopus databases) was conducted independently by two reviewers. The pooled prevalence with 95% confidence intervals was estimated. Quality assessment as well as outlier and influential analysis were performed. Additionally, subgroup and meta-regression analysis were conducted in order the effect of categorical and continuous variables on the estimated prevalence to be investigated. In total, seventy-five eligible studies (comprising a sum of 5825 participants) were included in this meta-analysis. The overall prevalence of SSI following ORIF for mandibular fractures was estimated as high as 4.2% (95% CI 3.0-5.6%) with significant heterogeneity between studies. One study was identified to be critically influential. In the subgroup analysis, the prevalence was 4.2% (95% CI 2.2-6.6%) among studies conducted in Europe, 4.3% (95% CI 3.1-5.6%) among studies conducted in Asia and higher among those conducted in America (7.3%) (95% CI 4.7-10.3%). It is important for healthcare professionals to be aware of the etiology of these infections, despite the relatively low rate of SSI in these procedures. However, further, well-designed prospective and retrospective studies need to be conducted in order this issue to be fully clarified.

Há diferença na força de compressão interfragmentar entre parafusos com rosca total ou parcial? Resultados de um estudo biomecânico experimental piloto

Objetivo Este estudo avaliou diferenças entre parafusos com rosca total ou parcial na resistência à compressão interfragmentar inicial. Nossa hipótese era de que haveria maior perda de resistência à compressão inicial com o parafuso de rosca parcial.

Métodos Uma linha de fratura oblíqua de 45 graus foi criada em amostras de osso artificial. O primeiro grupo (TOTAL, n = 6) foi fixado com um parafuso de 3,5 mm de rosca total, enquanto o segundo grupo (PARCIAL, n = 6) usou um parafuso de 3,5 mm de rosca parcial. Avaliamos a rigidez à torção em ambas as direções de rotação. Os grupos foram comparados com base nos seguintes parâmetros biomecânicos: momento de rigidez-ângulo, momento de rigidez-tempo, momento de torção máxima (carga de falha) e força de compressão calibrada com base na medida do sensor de pressão.

Resultados Depois da perda de uma amostra PARCIAL, não foram observadas diferenças estatisticamente significativas na força de compressão calibrada entre os 2 grupos [mediana (intervalo interquartil)]: TOTAL: 112,6 (10,5) N e PARCIAL: 106,9 (7,1) N, com p = 0,8 segundo o teste U de Mann-Whitney). Além disso, após a exclusão de 3 amostras para testes mecânicos (TOTAL, n = 5, PARCIAL, n = 4), não foram observadas diferenças estatisticamente significativas entre os construtos TOTAL e PARCIAL quanto ao momento de rigidez-ângulo, momento de rigidez-tempo ou momento de torção máxima (carga de falha).

Conclusão Não há diferença aparente na força de compressão inicial (força de compressão ou rigidez do construto ou carga de falha) com o uso de parafusos de rosca total ou parcial neste modelo biomecânico em osso artificial de alta densidade. Parafusos de rosca total podem, portanto, ser mais úteis no tratamento de fraturas diafisárias. Mais pesquisas são necessárias sobre o impacto em modelos ósseos osteoporóticos ou metafisários de menor densidade e avaliação do significado clínico.

Cortical lag screw fixation for the management of mandibular injuries

Objectives

Here, we present cases of mandibular fracture that were managed with the cortical lag screw fixation technique (CLSFT) in order to critically evaluate technique indications and limitations of application at various fracture sites.

Materials and Methods

This was a retrospective cohort study. The study sample was composed of patients suffering from mandibular fractures that were treated by the CLSFT. The outcome variables were fracture type, duration of surgery, number of screws, and pattern of application. Other study categories included patient demographics and causes of injury. Chi-square tests were used to assess descriptive and inferential statistical differences, and the P-value was set at 0.05.

Results

Thirty-three patients were included in the study sample, with a mean age of 30.9±11.5 years and a male predominance of 81.8%. The technique was applied more frequently in the anterior mandibular region (51.5%) than in other sites. Double CLSFT screws were required at the symphysis and parasymphysis, while single screws were used for body and angle regions. No intraoperative and postoperative variables were significantly different except for surgical duration, which was significantly different between the sites studied (P=0.035).

Conclusion

We found that CLSFT is a rapid, cost-effective technique for the fixation of mandibular fractures yielding good treatment results and very limited complications. However, this technique is sensitive and requires surgical expertise to be applied to mandibular fractures that have specialized characteristics.