title: Removal of restrictions following primary THA with posterolateral approach does not increase the risk of early dislocation.
abstract: OBJECTIVE
  Patient education and mobilization restrictions are often used in an attempt to reduce the risk of dislocation following primary THA. To date, there have been no studies investigating the safety of removal of mobilization restrictions following THA performed using a posterolateral approach. In this retrospective non-inferiority study, we investigated the rate of early dislocation following primary THA in an unselected patient cohort before and after removal of postoperative mobilization restrictions.
  
  
  METHODS
  From the Danish National Health Registry, we identified patients with early dislocation in 2 consecutive and unselected cohorts of patients who received primary THA at our institution from 2004 through 2008 (n = 946) and from 2010 through 2014 (n = 1,329). Patients in the first cohort were mobilized with functional restrictions following primary THA whereas patients in the second cohort were allowed unrestricted mobilization. Risk of early dislocation (within 90 days) was compared in the 2 groups and odds ratio (OR)-adjusted for possible confounders-was calculated. Reasons for early dislocation in the 2 groups were identified.
  
  
  RESULTS
  When we adjusted for potential confounders, we found no increased risk of early dislocation within 90 days in patients who were mobilized without restrictions. Risk of dislocation within 90 days was lower (3.4% vs 2.8%), risk of dislocation within 30 days was lower (2.1% vs 2.0%), and risk of multiple dislocations (1.8% vs 1.1%) was lower in patients who were mobilized without restrictions, but not statistically significantly so. Increasing age was an independent risk factor for dislocation.
  
  
  CONCLUSIONS
  Removal of mobilization restrictions from the mobilization protocol following primary THA performed with a posterolateral approach did not lead to an increased risk of dislocation within 90 days.
authors.affiliation: Department of Orthopaedic Surgery and.
authors.forename: Kirill
authors.initials: K
authors.lastname: Gromov
authors.forename: Anders
authors.initials: A
authors.lastname: Troelsen
authors.forename: Kristian Stahl
authors.initials: KS
authors.lastname: Otte
authors.forename: Thue
authors.initials: T
authors.lastname: Ørsnes
authors.forename: Steen
authors.initials: S
authors.lastname: Ladelund
authors.forename: Henrik
authors.initials: H
authors.lastname: Husted
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015331:Cohort Studies; D003718:Denmark; D005260:Female; D006617:Hip Dislocation / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010353:Patient Education as Topic; D012189:Retrospective Studies; D012307:Risk Factors; D057185:Sedentary Behavior; D013997:Time Factors; D055815:Young Adult