title: Fluid Extravasation Related to Hip Arthroscopy: A Prospective Computed Tomography-Based Study.
abstract: BACKGROUND
  Complications related to hip arthroscopy are rare, with a current rate of <2%. Some complications are related to fluid extravasation, which has been associated with life-threatening conditions such as abdominal compartment syndrome, cardiopulmonary arrest, hypothermia, and atelectasis.
  
  
  OBJECTIVE
  To identify risk factors for fluid volume extravasation in hip arthroscopy and to determine the relationship between anatomical location on computed tomography (CT) and extravasated volume.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  We performed a prospective cohort study of 40 consecutive arthroscopies for femoroacetabular impingement. Patient demographics and procedures performed (ie, acetabuloplasty and its size, femoral osteoplasty, and psoas tenotomy) were recorded. The extravasated volume was estimated by the difference between the infused volume and the intraoperatively collected volume. Within 12 hours after the procedure, the pelvis was scanned by CT. We created a 3-stage radiological classification based on progressive involvement of anatomical structures attributed to liquid extravasation. Statistical analyses were performed with a 95% CI and a significance level of 5%.
  
  
  RESULTS
  No relevant clinical symptoms related to fluid extravasation were recorded. The mean extravasated volume was 3.06 L at a rate of 1.05 L/h, corresponding to nearly 10% of the infused volume. There was a trend toward greater extravasated volume with longer operative time and longer time in the peripheral compartment (without axial traction); however, there was no statistical significance. The anatomical classification on CT imaging was directly related to the extravasated volume and compromised the thigh, gluteus, and retroperitoneum and intraperitoneal spaces. There was a 6-fold greater probability of female patients having an advanced stage extravasation on CT classification.
  
  
  CONCLUSIONS
  In our series, 10% of the infused volume was extravasated in uncomplicated hip arthroscopy. Risk factors for extravasation were related to operative time, particularly during peripheral compartment intervention (ie, without traction). The anatomical classification proposed in this study reflects the progressive involvement of the thigh, gluteus, iliopsoas, and retroperitoneal and intraperitoneal spaces after increase in extravasated volume. Compared with males, females were associated with more severe anatomical compromise for the same extravasated volume.
authors.affiliation: Department of Orthopaedic Surgery, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Jaime
authors.initials: J
authors.lastname: Hinzpeter
authors.affiliation: Department of Orthopaedic Surgery, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Cristián
authors.initials: C
authors.lastname: Barrientos
authors.affiliation: Department of Orthopaedic Surgery, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Maximiliano
authors.initials: M
authors.lastname: Barahona
authors.affiliation: Department of Imaging, Musculoskeletal Radiology Unit, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Jorge
authors.initials: J
authors.lastname: Diaz
authors.affiliation: Department of Orthopaedic Surgery, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Zamorano
authors.affiliation: Department of Imaging, Musculoskeletal Radiology Unit, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Salazar
authors.affiliation: Department of Orthopaedic Surgery, Hospital Clínico Universidad de Chile, Independence, Chile.
authors.forename: Jaime
authors.initials: J
authors.lastname: Catalan
keywords: arthroscopy complications; extravasated volume; femoroacetabular impingement; hip arthroscopy