Medial Hoffa Fracture: A Case Report and Literature Review of Approach and Management.

BACKGROUND Hoffa fractures are an uncommon form of coronal fracture that impact the femoral condyle. As a result, they are not very prevalent. It is necessary to perform anatomical reduction and rigorous fixation on these fractures; however, there is no consensus among medical professionals on the surgical procedure and implant that would be the most successful in treating these fractures. CASE REPORT A 50-year-old woman who had poliomyelitis in her right lower limb presented with a displaced medial Hoffa fracture of her left knee. She had fallen and was suffering from poliomyelitis. The trauma that caused this fracture had a modest energy level. Open reduction and internal fixation with 2 retrograde cannulated screws were included in her surgical procedure. An approach known as the medial parapatellar route was used for this treatment. As part of her postoperative rehabilitation, she participated in physiotherapy, exercises that did not require weight bearing, exercises that used passive and active assistance, activities that involved partial and full weight bearing, and exercises that involved complete weight bearing. At the 2-year follow-up, the patient's left knee continued to be painless and stable, and it had unrestricted range of motion across the whole extremity. It was determined via radiographs that the fracture had healed without any problems or arthritic changes developing. She was able to walk without help and carry out her daily tasks since she was able to walk with the use of a cane. CONCLUSIONS Retrograde cannulated screws can be a reliable and successful choice for treatment of medial Hoffa fractures, with positive results according to both clinical and radiographic characteristics. Further research is needed to analyze the outcomes over a longer period of time and make comparisons between this technique and others.

Application of 3D Printing Technology in the Treatment of Hoffa's Fracture Nonunion / Aplicação da tecnologia de impressão 3D no tratamento da pseudartrose da fratura de Hoffa

Abstract Objective To evaluate a proposed three-dimensional (3D) printing process of a biomodel developed with the aid of fused deposition modeling (FDM) technology based on computed tomography (CT) scans of an individual with nonunion of a coronal femoral condyle fracture (Hoffa's fracture). Materials and Methods Thus, we used CT scans, which enable the evaluation of the 3D volumetric reconstruction of the anatomical model, as well as of the architecture and bone geometry of sites with complex anatomy, such as the joints. In addition, it enables the development of the virtual surgical planning (VSP) in a computer-aided design (CAD) software. This technology makes it possible to print full-scale anatomical models that can be used in surgical simulations for training and in the choice of the best placement of the implant according to the VSP. In the radiographic evaluation of the osteosynthesis of the Hoffa's fracture nonunion, we assessed the position of the implant in the 3D-printed anatomical model and in the patient's knee. Results The 3D-printed anatomical model showed geometric and morphological characteristics similar to those of the actual bone. The position of the implants in relation to the nonunion line and anatomical landmarks showed great accuracy in the comparison of the patient's knee with the 3D-printed anatomical model. Conclusion The use of the virtual anatomical model and the 3D-printed anatomical model with the additive manufacturing (AM) technology proved to be effective and useful in planning and performing the surgical treatment of Hoffa's fracture nonunion. Thus, it showed great accuracy in the reproducibility of the virtual surgical planning and the 3D-printed anatomical model.

Resumo Objetivo Avaliar uma proposta de processo de impressão tridimensional (3D) de um biomodelo preparado com o auxílio da tecnologia de modelagem por deposição de material fundido (fused deposition modeling, FDM, em inglês) a partir de imagens de tomografia computadorizada (TC) de um indivíduo com pseudartrose de fratura coronal do côndilo femoral (fratura de Hoffa). Materiais e Métodos Para tanto, utilizamos imagens de TC, que permitem estudar a reconstrução volumétrica 3D do modelo anatômico, além da arquitetura e geometria óssea de sítios de anatomia complexa, como as articulações. Também permite o planejamento cirúrgico virtual (PCV) em um programa de desenho assistido por computador (computer-aided design, CAD, em inglês). Essa tecnologia possibilita a impressão de modelos anatômicos em escala real que podem ser utilizados em simulações cirúrgicas para o treinamento e a escolha do melhor posicionamento do implante de acordo com o PCV. Na avaliação radiográfica da osteossíntese da pseudartrose de Hoffa, verificou-se a posição do implante no modelo anatômico impresso em 3D e no joelho do paciente. Resultados O modelo anatômico impresso em 3D apresentou características geométricas e morfológicas semelhantes às do osso real. O posicionamento dos implantes em relação à linha de pseudartrose e pontos anatômicos foram bastante precisos na comparação do joelho do paciente com o modelo anatômico impresso em 3D. Conclusão A utilização do modelo anatômico virtual e do modelo anatômico impresso em 3D com a tecnologia de manufatura aditiva (MA) foi eficaz e auxiliou o planejamento e a realização do tratamento cirúrgico da pseudartrose da fratura de Hoffa. Desta forma, foi bastante preciso na reprodutibilidade do planejamento cirúrgico tanto virtual quanto no modelo anatômico impresso em 3D.