Prognosis of orbital floor trapdoor fractures
with or without muscle incarceration
Received: 28 March 2007 / Accepted: 3 April 2007 / Published online: 15 May 2007
Abstract This study investigated postoperative prognosis
of orbital floor trapdoor fractures with or without muscle
incarceration by retrospectively reviewing medical records
and computed tomography scans of appropriate patients.
Orbital floor trapdoor fractures were present in nine orbits
of nine patients with muscle incarceration and in ten orbits
of ten patients without muscle incarceration. All patients
were operated on within a couple of days after admission
and were observed for more than 6 months postoperatively.
Mean time interval between injury and surgery was 4.8 days
(range, 1–14 days) in patients with muscle incarceration
and 10.3 days (range, 3–31 days) in patients without muscle
incarceration. Postoperative fields of binocular single vision
fully improved in all patients excluding two patients with
muscle incarceration and in all patients without muscle
incarceration. Insufficient improvements of ocular move-
ments were observed in two patients with muscle incarcer-
ation who had late surgical interventions. Orbital floor
trapdoor fractures showed good prognosis in patients with
muscle incarceration with emergent surgical intervention,
or in patients without muscle incarceration.
Orbital floor trapdoor fracture
Orbital trapdoor fractures require early surgical intervention
to achieve good eye motility [1–5, 8, 9, 15, 19]. Reduction
has been recommended to be conducted within either 2 days
, 2 to 4 days , 5 days , 7 days , or 2 weeks [1,
2, 15] from injury, demonstrating the variability in intervals
between injury and surgery.
The prognosis of orbital trapdoor fractures with or
without muscle incarceration has received scant attention
in the past . Recently, cases without muscle incarcer-
ation and mild eye motility disturbances were shown to
have good prognoses with no surgical intervention [5, 19].
However, prognosis of cases with severe eye motility
disturbances and with the need for surgical intervention
 has not yet been reported.
A few studies [6, 8] were performed in an attempt to
predict disturbances of eye motility of trapdoor fractures on
the basis of preoperative computed tomography (CT)
images. Because cases with or without muscle incarceration
were not separately examined in these previous studies,
postoperative eye motility in these two groups was unclear.
In this study, we investigated the postoperative progno-
ses of orbital floor trapdoor fractures based on the presence
or absence of muscle incarceration by reviewing medical
records and CT images from particular patients.
Materials and methods
A retrospective review of the medical records and CT scans
from 24 patients, obtained from April 2003 to February
2005, at Seirei Hamamatsu General Hospital was per-
formed. The patients presented with orbital floor trapdoor
fractures with or without muscle incarceration (Fig. 1a,b).
Eur J Plast Surg (2007) 30:53–56
The authors have no financial interest related to this manuscript.
H. Kakizaki (*)
Department of Ophthalmology, Aichi Medical University,
Aichi-gun, Aichi-ken 480-1195, Japan
Department of Oculoplastic and Orbital Surgery,
Seirei Hamamatsu General Hospital,