DOS 2016

134

· DOS Abstracts

High incidence in acute and recurrent patellar

dislocations; A retrospective nationwide

epidemiological study involving 24.154 primary

dislocations

Kasper Skriver Gravesen, Anders Troelsen, Lars Blønd, Kristoffer Weisskirchner

Barfod

Dept. of Orthopedic Surgery, Clinical Orthopedic Research Hvidovre (CORH),

Copenhagen University Hospital Hvidovre; Dept. of Orthopedic Surgery, Clinical

Orthopedic Research Hvidovre (CORH), Copenhagen University Hospital

Hvidovre; Dept. of Orthopedic Surgery, Zealand University Hospital Køge

and Aleris-Hamlet Parken; Dept. of Orthopedic Surgery, Clinical Orthopedic

Research Hvidovre (CORH), Copenhagen University Hospital Hvidovre

Background:

Reliable epidemiological data on patellar dislocation is lacking.

Purpose / Aim of Study:

The purpose of this study was to investigate the

Danish population as a whole from 1994 to 2013 to find the incidence of acute

and recurrent patellar dislocation. The risk of acquiring a recurrent dislocation or

a dislocation in the opposite knee was investigated with 10 years of follow up

after primary dislocation.

Materials and Methods:

The study was performed as a descriptive epidemio-

logical study. The Danish National Patient Registry was retrospectively searched

from 1994 to 2013 to find the number of acute and recurrent patellar dis-

location. National population data were collected at the services of Statistics

Denmark.

Findings / Results:

From 1994 to 2013 a total of 24.154 primary patellar

dislocations were registered. A mean incidence of 72 (95% CI: 63 - 81) per

100.000-person years at risk (PYRS) was found, young females aged 10-17

had an incidence of 108 (95% CI: 101-116). In a 10- year follow up patients

had an overall risk of 22.7% (95% CI: 22.2 – 23.2) of suffering a recurrent

dislocation, with young girls aged 10-17 athe t highest risk with 36.8% (95%

CI: 35.5 – 38.0). The overall risk of suffering a patellar dislocation in the con-

tralateral knee was 5.8% (95% CI: 5.5 – 6.1) and 11.1% (95% CI: 10.4 – 11.7)

for patients aged 10-17.

Conclusions:

A high incidence rate of primary patellar dislocation was found

both as a mean in the population (72/106) but especially in patients aged 10-

17 (108/106). The risk of recurrent dislocation in the affected knee (22.7%)

and the contralateral knee (5.8%) was high, which could indicate the influence

of an underlying pathomorphology.

No conflicts of interest reported

85.