A 9-year-old boy presented to a clinic
complaining of moderate-to-severe knee pain while doing sprints and kendo. He
was a sports person and was an active participant of multiple games including
basketball, running events, javelin throw, and so on. He was experiencing
moderate knee pain since past one month. However, since the pain was gradually
worsening, he rushed to the clinic. Upon presentation, there were no signs of
external injury or hemorrhage.
The
most likely diagnosis of this presentation is
Stress fractures are one of the most common
sports injuries and often characterized by localized bone or periosteal pain,
especially during the physical activity or playing. Stress fractures can result
from participation in multiple activities and sports, especially those
involving running, jumping and repetitive motions causing stress. However,
sports including hockey, golf, swimming, fencing, and softball are rarely
associated with stress fractures. Athletics, or track and field sports, account
for 50% of stress fractures in men and 64% in women. Fractures of
the patella account for around 1% of all fractures, indicating the rare
prevalence of patellar stress fractures. The recommended treatment approaches
for these fractures include surgical or conservative approach.
A young athlete presented with nonunion of
a transverse stress fracture of the proximal patella regained his physical
strength after internal fixation using Acutrak screws.
There were no signs of ligamentous laxity
and effusion. The range of motion was normal. However, there was a mild
stiffness at the left proximal patella. The x-ray showed a transverse fracture
of the left proximal patella suggesting a diagnosis of transverse stress
fracture of the left proximal patella. The femorotibial angle of the left knee
was 174° and that of the right knee was 176°. The roentgenographic
patellofemoral congruence was almost normal.
Initially, the patient was treated
conservatively for almost months and he was asked not to play any kind of
sports during the treatment. However, conservative treatment failed to relieve
the pain completely and the patient presented to the orthopedic department of
the hospital. Since the diagnosis of nonunion of a proximal transverse patella
stress fracture was confirmed through the radiograph, the surgical approach was
undertaken. Surgery involved a 2-cm anterior longitudinal incision over the
superior portion of the patella and the fracture was drilled and internally
fixed using Acutrak mini screws. Upon follow up after three months of surgery,
the knee pain was completely resolved and he returned to his previous sports
activities and daily routine.
The most common sites of stress fractures
in adult athletes include tibia, tarsal bones, metatarsal bones, femur, fibula,
pelvis, sesamoids, the spine. While in children, the common sites included
tibia, fibula, femur, radius, metatarsals, and the humerus. Risk factors
for stress factors are listed in Table 1. Stress fractures of the patella are
comparatively rare. In this case, the patient had fracture at the proximal
1/3.
Previous papers have
reported patellar stress fractures in soccer players, basketball players, and
runners. In this case, the repetitive increase in the patellofemoral joint
reaction force due to the Kendo, in addition to the sprints could be an important
aspect in the development of the transverse stress fracture.
A surgical approach
involving internal fixation with the tension band technique, the
cannulated screw technique, curettage, bone grafting, or drilling have all
been reported to be effective.
In this case, the repetitive movement with
90° left knee flexion induced by running sprints might have led to the
transverse stress fracture of the proximal patella. The nonunion of the
transverse stress fracture can be successfully treated with internal fixation
using Acutrak screws.
Medicine (Baltimore). 2016 Feb; 95(6): e2649
Transverse Stress Fracture of the Proximal Patella
Satoru Atsumi et al.
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