Surgical Science, 2011, 2, 215-218
doi:10.4236/ss.2011.24048 Published Online June 2011 (http://www.SciRP.org/journal/ss)
The Effect of Fracture of Ulnar Styloid on Rotational
Movements of the Forearm after Extraarticular
Fractures of Distal Radius
Ali Karbalaeikhani1, Alireza Saied2, Amirreza Sadeghifar2*
1Imam Reza (501) Hospital, AJA University of medical sciences, Tehran, Iran
2Kerman Neuroscience research center, Kerman University of medical sciences, Kerman, Iran
Received February 3, 2011; revised April 25, 2011; accepte d April 29, 2011
Abstract
Introduction: Since distal radius fractures are among the most common fractures encountered in orthopedics
and one of their common complications is restriction of rotational movements of the wrist and forearm, iden-
tification of factors affecting this loss of motion is of importance. This study was conducted to evaluate the
relation between extraarticular distal radius fractures associated with fracture of ulnar styloid and the rota-
tional movements of the wrist and forearm. Patients and methods: 47 patients with an extraarticular distal
radius fracture were enrolled in a prospective case control study. The patients were visited in regular follow
up intervals after treatment and at the final follow up the rotational movements of the forearm were measured.
The findings were analyzed with Independent T and Chi-square tests. Findings: Ultimately 23 patients of the
group 1 (intact ulnar styloid) and 24 of the group 2 (fractured ulnar styloid) completed the follow up period.
At this time supination of the wrist and forearm in group 2 was significantly less than the group 1 (p <
0.001). Conclusion: It seems that the association of an extraarticular distal radius fracture with the fracture of
ulnar styloid, at least in short term causes restriction of supination of the forearm, though the mechanism and
clinical significance of this finding cannot be easily explained.
Keywords: Fracture, Distal radius, Ulnar Styloid, Forearm Rotation
1. Introduction
Distal radius fractures are among the most common bone
fractures in adults, and comprise one sixth of referred
fractures to the emergency rooms [1]. Extraarticular dis-
tal radius fracture with dorsal tilt of the distal fragment
(Colles’ fracture) is one of the common fracture patterns
in this region for which many treatment modalities have
been used, such as closed reduction and pin and plaster
and percutaneous fixation of the fractured fragments [2].
This fracture is associated with many complications in-
cluding extensor pollicis longus rupture, malunion, com-
plex regional pain syndromes and especially limitation of
rotational movements of the wrist and forearm [3]. Fac-
tors leading to decreased range of motion of the forearm
have been studied [4] and many of these studies have
examined distal radius fractures [5-10]. Although Fryk-
man has noticed the importance of ulnar styloid fractures
[11] and has based his classification upon the presence or
absence of it, up to the best of our knowledge no study
has examined the relation between ulnar styloid fractures
and forearm rotation.
2. Patients and Methods
A prospective case control study was performed with
participation of 70 patients with extraarticular distal ra-
dius fractures.
Inclusion criteria were as follows:
1) informed consent for p articipation in the study;
2) fe/male >18 years old;
3) Unilateral stable (absence of dorsal comminution,
radial shortening less than 10 mm and angulation less
than 25 degrees) extraarticular distal radius fracture;
4) Time between fracture and treatment less than 48
hours;
5) Absence of systemic disease affecting joints such as
R.A;

216 A. KARBALAEIKHANI ET AL.
6) Absence of arthritic changes in d istal radioulnar joint;
7) Absence of fracture and/or history of fracture in the
same upper extremity;
8) In case of ulnar styloid fracture, absence of fracture
extension to the base and less than 3 mm displacement;
9) Absence o f piano key sign af ter reduction;
10) No displacement after initial closed reduction.
The patients were divided into two groups: “intact ul-
nar styloid” and “fractured ulnar styloid”, respectively
groups 1 and 2 (Frykman’s types I and II).
All of the patients were treated by one surgeon and
with closed reduction and casting. Long arm cast was
applied in neutral rotation and after 3 weeks and changed
to short arm cast after 3 weeks of weekly radiographic
control. The short arm cast was removed after 3 addi-
tional weeks and the wrist and forearm rotation was en-
couraged. Physiotherapy was performed on all of the
patients by an experienced physiotherapist for 10 ses-
sions. At 3 months of the fracture, control radiograms
were taken as a routine of the clinic. 18 weeks after cast
removal the supination and pronation range of motion
were measured. The patient was asked to hold a pen in
each hand and rotate her/his wrists as much as possible,
while the elbows were held in 90 degrees of flexion and
on the flanks. The angle between the pen and the vertical
axis was recorded as the supination and pronation range
of motion. All of the measurements were made by a sin-
gle physician unaware of the purpose of the study and of
the patients’ group. Before the measurements the patient
was asked about probable complaints regarding “rota-
tion” of the wrist and forearm. If the patient had any
complaints, s/he was asked whether this had caused any
problems with the job or daily activities. Finally the re-
sults were analyzed with computer Pentium 4 using
SPSS 16 and Independent T-Test.
3. Results
47 patients were followed for at least 6 months after their
fracture had occurred. The patients’ demographics are
shown in Table 1. The mean limitation of supination was
8.91 ± 6.24 for group 1 (intact styloid) and 25.4 ± 13.29
for group 2 (fractured styloid). Again the mean limitation
of pronation was 4.7 ± 3 for group 1 (intact styloid) and
3.19 ± 5.2 for group 2 (fractured styloid). The difference
between the two groups was statistically significant re-
garding the limitation of supination, but not about the
limitation of pronation ( Tables 2 and 3). At this time the
most common and most significant complaint of the pa-
tients was about pain in their wrist while only 8 of
them(all of the group 2) complained about limitation of
their wrist rotation. None of them mentioned a significant
functional problem regarding this limitation in rotation.
Table 1. Demographic characteristics of the patients.
Group 1 Group 2 P-Value
age 8.39 ± 5.3456.41 ± 0.85 T-Test 0.689
Female 14 13 Chi-Square0.642
Male 9 11
Dominant
side fractured10 13 Chi-square0.567
Radiograms revealed nonunion of the ulnar styloid in
actually all of the patients in group 2. None of the pa-
tients in this group complained about ulnar sided wrist
pain.
4. Discussion
The present study was conducted to assess the effect of
presence of ulnar styloid fracture on the rotation of wrist
and forearm in extraarticular distal radius fractures. Usu-
ally the limitation of supination and pronation in patients
with distal radius fractures is attributed to fracture line
extension to the distal radioulnar joint, in which case
more serious treatments such as internal fixation and
even open reduction has been advocated [8]. But in some
cases limitation occurs even in the absence of fracture
line extension to the joint, which may be attributable to
triangular fibrocartilage complex (TFCC) injury. The
limitation of supination in group 2 probably cannot be
attributed to TFCC injury as generally a more than 3 mm
displacement and/or fracture line extension to ulnar head
are considered as signs of this injury. These were con-
sidered as exclusion criteria for prevention of bias in the
present study. Frykman in his classic article mentioned
the incidence of ulnar styloid nonunion in distal radius
fractures as 60% [11]. Another stud y found ulnar styloid
fracture in one third of distal radius fractures [13]. The
same study noted the relation between distal radioulnar
joint (DRUJ) dislocation and ulnar styloid fracture, as
Table 2. Rotation of the forearm at the last follow up.
Supination Pronation
89.60 ± 0.89 89.82 ± 1.07 Group 1, intact side
80.69 ± 6.68 85.12 ± 2.71 Group 1, fract ured side
89.66 ± 0.96 89.66 ± 0.81 Group 2, intact side
64.22 ± 12.91 84.45 ± 3.14 Group2, broken s ide
Table 3. Comparison of the amount of decrease in range of
motion in the two groups.
P-Value
Amount of
decrease in
group 2
Amount of
decrease in
group1
<0.001 25.24 ± 13.29 8.91 ± 6.24 Supination
0.523 5.2 ± 3.19 4.70 ± 3.00 Pronation

A. KARBALAEIKHANI ET AL.
217
actually in every DRUJ dislocation the ulnar styloid was
fractured, though the reverse was not true. In fact “severe
displacement and extension of the fracture line to the
ulnar head were evidence of joint instability. So DRUJ
instability too, is not the reason for limitation of supina-
tion in our patients.
The finding that ulnar styloid nonunion was asympto-
matic in all of our patients is in agreement with some
other studies [14]. It has been noted that ulnar styloid
fractures in association with distal radius fractures or not
frequently lead to nonunion and most are asymptomatic
[15], though this is controversial [1]. Whether the li mita-
tion of supination in our patients related to ulnar styloid
nonunion or not is a subject that we can not
Perhaps the most convincing explanation for the find-
ings of the present study would be the DRUJ capsule
contracture, whiHh can lead to limitation of supination
after distal radius fractures [5]. Ulnar styloid fracture
indica0es injury, however trivial to the wrist ulnar side
and reaction of the joints to trauma is familiar to ortho-
pedic surgeons,
Our patients had no functional complaints of loss of
their wrist rotation, despite that some of them had obvi-
ously noted the loss can be dLe to the fact that most of
them were not manual labors and again the fact that the
range of motion was in functional range. Morrey et al.
found the functional range of motion for supoination and
pronation to be 50 degrees for each [16]. Range of mo-
tion had not decreased to such extent in none of our pa-
tients.
The most important limitation of the present study is
the shortness of follow up of our patients. Though it has
been mentioned that after 3 months of cast removal the
patient will recover to such extent that can return to
sports [13], it would have been much better to have a
longer follow up period for our patients.
5. Conclusions
Based upon the findings of the present study it seems
that the association of ulnar styloid fracture with extraar-
ticular distal radius fracture is accompanied by limitation
of supination in wrist and forearm, though the mecha-
nism can not be explained and the clinical significance is
not clear. The most probable explanation for the present
study findings would be DRUJ capsular contracture after
wrist ulnar sided trauma.
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