title: Primary patellar dislocations without surgical stabilization or recurrence: how well are these patients really doing?
abstract: OBJECTIVE
  While a significant research has gone into identifying patients at highest risk of recurrence following primary patellar dislocation, there has been little work exploring the outcomes of patients who do not have a recurrent patellar dislocation. We hypothesize that patients without recurrent dislocation episodes will exhibit significantly higher KOOSs than those who suffer recurrent dislocations, but lower scores than published age-matched normative data.
  
  
  METHODS
  A retrospective review of patients with nonoperatively treated primary lateral patellar dislocations was carried out, and patients were contacted at a mean of 3.4 years (range 1.3-5.5 years) post-injury. Information regarding subsequent treatment and recurrent dislocations along with patient-reported outcome scores and activity level was collected.
  
  
  RESULTS
  One hundred and eleven patients (29.8 %) of 373 eligible patients agreed to study participation, seven of whom were excluded because they underwent subsequent patellar stabilization surgery on the index knee. Seventy-six patients (73.1 %) reported no further dislocation events, and the mean KOOS subscales at follow-up were: symptoms-80.2 ± 18.8, pain-81.8 ± 16.2, ADL-88.7 ± 15.9, sport/recreation-72.1 ± 24.4, and QOL-63.9 ± 23.8 at a mean follow-up of 3.3 years (range 1.3-5.5 years). No significant differences in any of the KOOS subscales were noted between these patients and the group that reported recurrent patellar dislocations. Only 26.4 % of the patients without further dislocations reported they were able to return to desired sport activities without limitations following their dislocation.
  
  
  CONCLUSIONS
  Patients who do not report recurrent patellar dislocations following nonoperative treatment of primary patellar dislocations are in many cases limited by this injury 3 years following the initial dislocation event.
  
  
  METHODS
  Retrospective cohort study, Level III.
authors.affiliation: Department of Orthopaedics, Sports Health and Performance Institute, The Ohio State University, Columbus, OH, 43214, USA. robert.magnussen@gmail.com.|Sports Health and Performance Institute, The Ohio State University, Columbus, OH, USA. robert.magnussen@gmail.com.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Magnussen
authors.affiliation: Department of Orthopaedics, Sports Health and Performance Institute, The Ohio State University, Columbus, OH, 43214, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Verlage
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Stock
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Zurek
authors.affiliation: Department of Orthopaedics, Sports Health and Performance Institute, The Ohio State University, Columbus, OH, 43214, USA.|Sports Health and Performance Institute, The Ohio State University, Columbus, OH, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Flanigan
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA.|TRIA Orthopaedic Center, Bloomington, MN, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Tompkins
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Agel
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Arendt
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D000072700:Conservative Treatment; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D031222:Patellar Dislocation / Q000601:surgery / Q000628:therapy*; D000071066:Patient Reported Outcome Measures; D020127:Recovery of Function; D012008:Recurrence; D012189:Retrospective Studies; D000068958:Return to Sport; D055815:Young Adult
keywords: Nonoperative; Patellar instability; Patient-reported outcomes