title: Incidence of Deep Venous Thrombosis After Tibial Tubercle Osteotomy: A Single Case Series Study.
abstract: BACKGROUND
  Tibial tubercle osteotomy (TTO) is performed in a predominantly young and often female population due to the prevalence of patellofemoral disorders in this group. While considered a procedure that falls within the realm of sports surgeries, the procedure can carry significant morbidity, including infection, fracture, and deep vein thrombosis (DVT). The incidence of postoperative DVT in this population has not been described in the literature, although it has been mentioned anecdotally, and current guidelines do not address the issue of DVT prophylaxis in postoperative TTO patients.
  
  
  OBJECTIVE
  To describe the incidence of DVT after TTO and identify any predisposing factors.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Subjects who had undergone TTO by the senior author from 2002 to 2013 were identified, and a retrospective chart review was performed. Those who presented with symptomatic DVT confirmed with ultrasonography were reported. Demographic data, as well as potential risk factors such as body mass index, family history of bleeding/clotting disorders, duration of the nonweightbearing period, total tourniquet time, use of contraceptive medication, smoking status, and use of anticoagulants, were collected from the chart and analyzed for correlation with development of DVT.
  
  
  RESULTS
  A total of 156 patients were included in this study. Six patients were found to have developed symptomatic DVT during the first 6 weeks after surgery. The mean age at the time of surgery in the DVT group was 34.94 ± 6.57 years, compared with 26.26 ± 10.20 years in the non-DVT group (P = .04). Due to the small number of patients with positive findings, there was no statistically significant correlation between the development of DVT and factors such as nonweightbearing duration, tourniquet time, or the use of contraceptives.
  
  
  CONCLUSIONS
  The incidence of postoperative DVT in arthroscopic and sports procedures has been thought to be low. This case series reported a rate of 3.8% with symptomatic DVT after TTO, and patients diagnosed with DVT were significantly older than unaffected patients. It is anticipated that the actual rate including asymptomatic DVT would be higher, as only 60% of patients with DVT are symptomatic. More studies are needed to define the actual incidence in this population. Given the number of common risk factors in this population, including nonweightbearing duration and the use of oral contraceptive pills, future studies may show the advantage of chemical prophylaxis for DVT in this group.
authors.affiliation: Regeneration Orthopaedics, Chesterfield, Missouri, USA.
authors.forename: Miho J
authors.initials: MJ
authors.lastname: Tanaka
authors.affiliation: Hospital for Special Surgery, New York, New York, USA.
authors.forename: Jacqueline L
authors.initials: JL
authors.lastname: Munch
authors.affiliation: Hospital for Special Surgery, New York, New York, USA.
authors.forename: Alissa J
authors.initials: AJ
authors.lastname: Slater
authors.affiliation: Hospital for Special Surgery, New York, New York, USA.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Nguyen
authors.affiliation: Hospital for Special Surgery, New York, New York, USA.
authors.forename: Beth E
authors.initials: BE
authors.lastname: Shubin Stein
keywords: age; deep vein thrombosis; patellofemoral instability; tibial tubercle osteotomy