Download Avulsion-fracture of the anterior superior iliac spine with meralgia

Journal of Orthopaedic Surgery 2011;19(3):384-5
Avulsion-fracture of the anterior superior
iliac spine with meralgia paresthetica: a case
report
Shinya Hayashi, Takayuki Nishiyama, Takaaki Fujishiro, Noriyuki Kanzaki, Masahiro Kurosaka
Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
ABSTRACT
We present a rare case of avulsion-fracture of
the anterior superior iliac spine with meralgia
paresthetica in a 16-year-old male basketball player.
He had sensory disturbance affecting his left lateral
thigh 10 days after the injury. Tinel’s sign was elicited
on percussing the avulsed bony fragment of the
anterior superior iliac spine. He underwent open
reduction and internal fixation. The lateral femoral
cutaneous nerve was noted to be entrapped by one
third of the avulsed bony fragment. That fragment
was removed, and the remaining portion was reduced
and fixed with 2 screws. At week 6, the patient had
returned to basketball playing without pain. At week
8, sensory distribution in the left lateral thigh had
returned to normal.
Key words: basketball; fracture, bone; ilium; meralgia
paresthetica
INTRODUCTION
Avulsion-fractures of the anterior superior iliac
spine are unusual injuries and mostly occur during
the kicking phase of running, football, and longjumping,1,2 when the sartorius and tensor fascia lata
muscles contract suddenly against a hyperextended
trunk. Meralgia paresthetica is a neuropathy of
entrapment of the lateral femoral cutaneous nerve.
Two cases of anterior superior iliac spine avulsionfracture associated with meralgia paresthetica have
been reported.3,4
CASE REPORT
In December 2009, a 16-year-old man presented
with swelling and tenderness of the left anterior
superior iliac spine but no sensory disturbance.
He had experienced sudden onset of sharp pain
in the left pelvis while playing basketball a day
earlier. Radiographs revealed an avulsion-fracture
of the anterior superior iliac spine with minimum
displacement. The patient was treated conservatively
with pain relief, limitation of activities, and crutches.
One week later, the patient had sensory
disturbance affecting his left lateral thigh. Tinel’s
sign was elicited on percussing the avulsed bony
fragment of the anterior superior iliac spine. A
conduction test for the lateral femoral cutaneous
Address correspondence and reprint requests to: Dr Takayuki Nishiyama, Department of Orthopaedic Surgery, Kobe University
Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan. E-mail: [email protected]
Vol. 19 No. 3, December 2011
Avulsion fracture of the anterior superior iliac spine with meralgia paresthetica 385
nerve yielded inhibition of the amplitude of the
sensory nerve action potential on the left side,
indicative of meralgia paresthetica. The displacement
of the avulsed bony fragment had increased to 2
cm caudally on computed tomography (Fig. 1). He
underwent open reduction and internal fixation 10
days after the injury. The lateral femoral cutaneous
nerve was noted to be entrapped by one third of the
avulsed bony fragment (Fig. 2). That fragment was
removed, and the remaining portion was reduced
and fixed with 2 screws.
Walking with full weight bearing was allowed
immediately. At week 6, the patient had returned to
basketball playing without pain. At week 8, sensory
distribution in the left lateral thigh had returned to
normal.
Figure 1 Computed tomographic scan showing an avulsionfracture of the left anterior superior iliac spine (arrow).
Medial
Caudal
Carnial
Lateral
Figure 2 The lateral femoral cutaneous nerve (black arrow)
is entrapped by a third of the avulsed bony fragment (dotted
arrow). The sartorius muscle (white arrow), the remaining
avulsed bony fragment (gray arrow), and anterior superior
iliac spine (slashed arrow) are also shown.
DISCUSSION
Meralgia paresthetica is characterised by pain,
burning, tingling or numbness in the anterolateral
surface of the thigh in the region supplied by the
lateral femoral cutaneous nerve. This nerve crosses the
ilium obliquely and passes into the thigh by traversing
under or through the inguinal ligament at a variable
distance medial to the anterior superior iliac spine.5
In our patient, the lateral femoral cutaneous nerve
originally passed some distance medial to the anterior
superior iliac spine and was pulled down beneath it as
a result of the fracture. The nerve was then entrapped
by one third of the avulsed bony fragment.
Acute onset of meralgia paresthetica should
be treated conservatively, as it could be caused by
oedema and haematoma irritating the nerve rather
than by direct contact between the nerve and the
avulsed anterior superior iliac spine fragment.3 In
our patient, the onset of meralgia paresthetica was
not acute but ensued gradually one week after injury,
suggesting entrapment of the nerve by the displaced
avulsed bony fragment. Operative treatment enables
early return to sports activity.6
REFERENCES
1. Hansson G. Bilateral avulsion fracture of the anterior superior iliac spine. Report of a case. Acta Chir Scand 1970;136:85–6.
2. Khoury MB, Kirks DR, Martinez S, Apple J. Bilateral avulsion fractures of the anterior superior iliac spines in sprinters.
Skeletal Radiol 1985;13:65–7.
3. Thanikachalam M, Petros JG, O’Donnell S. Avulsion fracture of the anterior superior iliac spine presenting as acute-onset
meralgia paresthetica. Ann Emerg Med 1995;26:515–7.
4. Buch KA, Campbell J. Acute onset meralgia paraesthetica after fracture of the anterior superior iliac spine. Injury
1993;24:569–70.
5. Macnicol MF, Thompson WJ. Idiopathic meralgia paresthetica. Clin Orthop Relat Res 1990;254:270–4.
6. Kosanovic M, Brilej D, Komadina R, Buhanec B, Pilih IA, Vlaovic M. Operative treatment of avulsion fractures of the
anterior superior iliac spine according to the tension band principle. Arch Orthop Trauma Surg 2002;122:421–3.