Revista de Medicina Desportiva (English) November 2018 | Page 26

presence of an anterior isolated
ossicle that corresponds to its ossi-
fication center that was previously
avulsed. 9-11
disappears and only a prominent
anterior tibial tuberosity will be left
(Figure 3). 5-8,16,17
Natural history
The echography over the patellar
tendon, including its tibial inser-
tion, can be a good diagnostic test.
MRI can be indicated when there
are still doubts after clinical evalua-
tion. 4,6-8,12,15,19
Etiology
It is unknown the etiology os OSS,
although there are several studies
that associate this pathology to
some variations that increase the
traction strength of the extensor
apparatus over the anterior tibial
tuberosity: pronated feet, valgus
knees and medial rotation and
patella alta. 13-15
The majority of the researchers
indicate that OSS is a self-limiting
pathology, with spontaneously reso-
lution, where 90% of the patients
will recover. About 10% of the
patients will have the symptoms
until adulthood independently of the
conservative treatment. 5-7, 16,17
Differential diagnosis
Clinical presentation
The symptomatology varies from
slight local discomfort to incapaci-
tating pain. Usually is characterized
by a vague gradual increasing pain
and a tumefaction located over the
tibial tuberosity. On the beginning,
there is moderate and intermittent
pain. During the acute phase pain
is severe, continuous with signifi-
cant functional incapacity. The pain
worsens after physical exercise,
especially if it involves jumps and
running, like basketball, volleyball
and running, and /or direct con-
tact, like kneeling. 16 Pain is often of
mechanical type that relieves when
there isn’t tension over the extensor
apparatus of the knee.
So, the typical clinical picture
includes a male adolescent, between
12 and 15 years of age, involved on
physical exercise, that indicates pain
and shows a tumefaction over the
anterior tibial tuberosity, gradually
onset on nature, that aggravates
after physical activity. During the
acute phase there is tenderness,
tumefaction and prominence on the
tibial tuberosity. Pain can be repro-
ducible by local palpation and resis-
tive knee extension, which is a test
that stresses the extension appara-
tus of the knee and causes traction
on the anterior tibial tuberosity.
If the patient is unable to actively
extends the knee it must be considered
and eventual complete avulsion
of the anterior tibial tuberosity or
a compromise on the tendinous
extension mechanism. After acute
phase, pain and tumefaction usually
24 november 2018 www.revdesportiva.pt
On all young physical practition-
ers with gradual arising knee pain,
that worsens during and after sports
practice, either unilateral or bilat-
eral, it should be considered, besides
OSS, the following diagnosis: Sind-
ing-Lansen-Johansson syndrome, a
similar osteochondrosis that afflicts
the lower extremity of the patella
bone, the Hoffa syndrome, which
is an inflammation of the fat pad
under the patellar tendon, and a
fracture of the anterior tibial tuber-
osity. It also must be considered are
the patelofemoral pain, infections
and tumors. 18,19
Complementary diagnostic tests
The diagnosis of OSS is mainly
clinical and rarely the exams are
needed. 8 A profile knee X-ray with
the lower limb on 10-30° of medial
rotation can show the irregularity of
the anterior tibial tuberosity, where
avulsion can be found on the initial
stages, but on the more advanced
stages there might exist fragmenta-
tion. In some cases, even after fusion
and closure of secondary ossification
center, it can be detected a unique
isolated anterior ossicle (Figure 4).
Figure 3 – The
lateral view of
the knee reveals
the prominent
tibial anterior
tuberosity on
an OSS case
(arrow).
Treatment
There aren’t any prospective, con-
trolled, randomized studies that
evaluated the bet treatment for
OSS. Therefore, in the literature
only retrospective studies are found
about the treatment of this pathol-
ogy. The symptomatic treatment is
recommended on the early stage.
During the symptomatic phase the
physical activity should be avoided
and the application of local ice,
nom-steroids anti-inflammatory
drugs and knee brace protectors
must be prescribed. Provided the
patient can handle it, physical
activity shouldn’t be forbitten at all.
The patients with moderate pain
and without functional impairment
should keep regular physical exer-
cise associated with nom-steroids
anti-inflammatory drugs and knee
brace protectors. On those patients
with severe pain, associated or not
to physical impairment, physical
activity should be avoided for a
few days. 6,8,13 Physiotherapy and a
conditioning and strength rehabilita-
tion program are a very important
component for the treatment of OSS.
They should be implemented right
after the acute phase and strength-
ening and stretching of the regional
muscle involved on the mobility of
the knee are recommended. Initially,
low intensity isometric exercises are
indicated and then exercises with
increasing intensity are prescribed.
Some studies demonstrate that
about 90% of the patients have good
results with the application of ice,
nom-steroids anti-inflammatory
drugs and relative rest. 20-22 However,
Figure 4 – A
profile knee X-ray
revealing the
ossicle at the tibial
tuberosity, typical
changes in the OSS
(arrow).