RESUMEN
Objective The present study analyzed the incidence of epiphyseal avascular necrosis in patients with slipped capital femoral epiphysis (SCFE) treated using a modified Dunn technique. In addition, this study determined the correlation of other variables with this incidence and described treatment complications. Methods This is a retrospective study with 20 patients treated by the same surgical team from 2009 to 2019 and followed up for 2 to 12 years. The analysis included general features, time from presentation to surgical procedure, classification, and intraoperative blood perfusion of the epiphysis, as well as complications and their treatment. Results All cases were severe; 65% were acute on chronic, and 55% of the SCFEs were unstable. Our complication rate was 45%, with 5 cases of avascular necrosis, 2 cases of deep infection, 1 case of material failure, and 1 case of joint instability. The statistical analysis revealed that the risk of necrosis was higher when the surgery occurred after a long hospitalization time and there was no intraoperative epiphyseal perfusion. Four necrosis cases happened within the first 5 years, and 1 case in the last 5 years of the study. Conclusion Our study showed that necrosis was the most common complication. It also revealed that surgery delay and lack of intraoperative epiphysis perfusion potentially predispose to avascular necrosis. Although with no statistical significance, coxofemoral instability occurred in chronic SCFE, and surgical fixation with threaded wires was less effective than fixation with a cannulated screw. The modified Dunn procedure should be reserved for severe cases in which other techniques are not feasible and performed by an experienced, trained, and qualified team.
RESUMEN
Abstract Objective The present study analyzed the incidence of epiphyseal avascular necrosis in patients with slipped capital femoral epiphysis (SCFE) treated using a modified Dunn technique. In addition, this study determined the correlation of other variables with this incidence and described treatment complications. Methods This is a retrospective study with 20 patients treated by the same surgical team from 2009 to 2019 and followed up for 2 to 12 years. The analysis included general features, time from presentation to surgical procedure, classification, and intraoperative blood perfusion of the epiphysis, as well as complications and their treatment. Results All cases were severe; 65% were acute on chronic, and 55% of the SCFEs were unstable. Our complication rate was 45%, with 5 cases of avascular necrosis, 2 cases of deep infection, 1 case of material failure, and 1 case of joint instability. The statistical analysis revealed that the risk of necrosis was higher when the surgery occurred after a long hospitalization time and there was no intraoperative epiphyseal perfusion. Four necrosis cases happened within the first 5 years, and 1 case in the last 5 years of the study. Conclusion Our study showed that necrosis was the most common complication. It also revealed that surgery delay and lack of intraoperative epiphysis perfusion potentially predispose to avascular necrosis. Although with no statistical significance, coxofemoral instability occurred in chronic SCFE, and surgical fixation with threaded wires was less effective than fixation with a cannulated screw. The modified Dunn procedure should be reserved for severe cases in which other techniques are not feasible and performed by an experienced, trained, and qualified team.
Resumo Objetivo Analisar a incidência da necrose avascular da epífise no tratamento do escorregamento da epífise proximal do fêmur pela técnica de Dunn modificada, correlacionando-a com outras variáveis. Como objetivo secundário, descrevemos outras complicações encontradas. Métodos Estudo retrospectivo com 20 pacientes tratados entre 2009 e 2019, com seguimento de 2 a 12 anos, tratados pela mesma equipe cirúrgica. A análise incluiu características gerais, tempo entre apresentação e procedimento cirúrgico, classificação, presença de perfusão sanguínea intraoperatória da epífise, avaliação das complicações e seus respectivos tratamentos. Resultados Todos os casos eram graves, 65% crônicos agudizados e 55% dos escorregamentos eram instáveis. Nossa taxa de complicações foi de 45%, sendo 5 casos de necrose avascular, 2 de infecção profunda, uma falha do material e uma instabilidade articular. Pacientes operados com maior tempo após a internação e os sem perfusão intraoperatória da epífise tiveram maior risco de necrose na análise estatística. Considerando o tempo do estudo, tivemos 4 casos de necrose nos primeiros 5 anos e 1 caso nos últimos 5 anos. Conclusão Nosso estudo demonstrou que a necrose foi a complicação mais comum e que o atraso para a realização da cirurgia e a ausência de perfusão da epífise no intraoperatório podem predispor à necrose avascular. Embora não estatisticamente significante, a instabilidade coxofemoral foi observada na forma de apresentação crônica e a fixação cirúrgica com fios rosqueados se mostrou menos eficaz que a fixação com parafuso canulado. Este procedimento deve ser reservado para casos graves nos quais outras técnicas não sejam possíveis e realizado por equipe experiente, treinada e capacitada.