HIP DISLOCATION, ANATOMICAL DESCRIPTION, EPIDEMIOLOGY, MECHANISMS OF ACTION, CLASSIFICATION, CLINICAL PRESENTATION, IMAGING PRESENTATION, TREATMENT, COMPLICATIONS AND DISLOCATION AFTER TOTAL HIP REPLACEMENT

Abstract

Introduction: Traumatic hip dislocation is an uncommon injury, approximately making up 2 to 5% of all dislocations generated by high-energy trauma. This type of dislocation can be pure or related to other injuries or alterations such as fracture of the femoral head, femoral neck or acetabulum. Objective: to detail the current information related to hip dislocation, anatomical description, epidemiology, mechanisms of action, classification, clinical presentation, imaging presentation, treatment, complications and dislocation after total hip replacement. Methodology: a total of 30 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 21 bibliographies were used because the other articles were not relevant to this study. The sources of information were PubMed, SciELO, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: hip dislocation, proximal femur, femoroacetabular dislocation, prosthetic dislocation. Results: Anterior dislocations account for 10% to 15% of traumatic hip dislocations, with the remainder being assigned to posterior dislocations. The incidence of osteonecrosis of the femoral head is between 2% to 17% of individuals, while 16% form post-traumatic osteoarthritis. The sciatic nerve is affected in about 10% to 20% of posterior dislocations. There is no correlation between early weight bearing and osteonecrosis. Dislocation of the total hip endoprosthesis is observed in about 2% of individuals within one year after surgery. There are dislocation rates of up to 28% following revision and implant exchange surgeries. Conclusions: The capsular ligaments of the hip joint (iliofemoral, ischiofemoral, and pubofemoral) act very importantly in the functional mobility and stability of the joint. Hip dislocations are caused by high-energy trauma, such as traffic accidents, which are becoming more common due to the increase of these. Posterior dislocations are more common compared to anterior hip dislocations. A complete and thorough trauma evaluation is important in the clinical assessment. Those with a posterior dislocation of the hip show marked pain and the hip in flexion, internal rotation and adduction. Those with an anterior dislocation remain with the hip in marked external rotation, slight flexion and abduction. The importance of an anteroposterior projection of the pelvis and a cross lateral projection of the injured hip is emphasized. Treatment may be closed or open reduction depending on the circumstances, clinical situation and associated injuries. Complications such as osteonecrosis may be associated with the time of evolution. The treatment of instability following total hip replacement should follow a standardized algorithm. KEY WORDS: dislocation, hip, femur, acetabulum, prosthesis.