Keywords
bone and bones - knee fractures - osteochondritis
Introduction
Articular cartilage is a connective tissue covering the bony surfaces of joints. It
is avascular, highly hydrated, and has no neural components.[1] In joint trauma, injuries can be purely chondral or associated with bone fragments,
configuring an osteochondral injury.[2]
[3]
The standard technique for fixation is open reduction and internal fragment fixation
with screws. However, these screws require removal in a second surgical procedure.
Bioabsorbable synthetic material use is not widespread and can induce foreign body
reactions.[4] As such, this study aims to report a technique for osteochondral fragment fixation
in the knee using autologous bone sticks from tibial cortical bone.
Case Report
The Research Ethics Committee of our institution approved this case report under the
number (CAAE 68381222.0.0000.5304). The patient's guardian signed the informed consent
form.
A male, 13-year-old patient, previously healthy, arrived at the consultation with
a history of trauma to the right knee, 2 days prior, resulting from a valgus stress
mechanism during soccer practice. Since the event, the patient had moderate pain,
inability to mobilize the knee, and 2 +/4+ effusion. The radiographic examination
revealed a dislocated osteochondral fragment of the lateral condyle of the right knee
measuring approximately 3 cm in its largest diameter ([Fig. 1]).
Fig. 1 Initial X-ray.
Therefore, we opted for surgical treatment, i.e., open reduction and internal fixation
with the cortical bone stick technique.
The surgery occurred 14 days after initial care. We performed a longitudinal lateral
parapatellar arthrotomy, measuring approximately 8 cm, on the patient's right knee.
Under direct visualization, the anatomical site was cleaned and grafted, and the fragment
measuring 35 mm × 27 mm was identified ([Fig. 2A]).
Fig. 2 Osteochondral fragments.
Next, we removed a cortical window from the middle diaphysis of the ipsilateral tibia
to create bone sticks. To do so, we made a 4-cm longitudinal skin incision over the
anteromedial proximal metaphysis of the right tibia. After elevating the periosteum,
we opened a window measuring approximately 30 × 15 mm, longer in the longitudinal
direction, with a saw to make bone sticks ([Fig. 2B] and [Fig. 3]).
Fig. 3 Post operative X-ray.
We prepared 5 cortical bone sticks, each measuring approximately 3 mm in diameter
and 30 mm in length. The provisional fixation of the osteochondral fragment employed
2.5-mm Kirschner wires. Each Kirschner wire was successively replaced by a bone stick.
Subsequently, we lowered the sticks to enter 3 mm into the articular surface. It is
worth highlighting that the fixation of the chondral fragment at the site of origin,
with the five bone sticks, occurred through an angular insertion divergent to the
surface ([Fig. 4]).
Fig. 4 Surgery image.
At discharge, we instructed the patient to perform exercises for early limb movement
with no support. Two weeks after surgery, he started motor physical therapy, walking
with crutches and no support. We allowed partial loading at 2 months and full loading
as tolerated at 4 months after surgery. The patient underwent periodical supplementary
imaging exams confirming the good evolution and right knee recovery. At 4 months,
the radiological examination demonstrated a proper bone consolidation of the fractured
fragment ([Fig. 5]).
Fig. 5 X-ray 4 months after the surgery.
The patient resumed his regular sports and impact activities 1 year and 2 months after
surgery. A follow-up magnetic resonance imaging (MRI) scan demonstrated the good evolution
of joint reconstruction ([Fig. 6]).
Fig. 6 Magnetic resonance 1 year and 2 months after the surgery.
Discussion
Osteochondral fractures of the lateral femoral condyle are infrequent.[3] Physical examination may reveal edema, movement limitation, and joint blockage.
The investigation must begin with a plain radiography. Pure chondral injuries require
other imaging tests, such as MRI and arthroscopy.[5]
After diagnosing an osteochondral fracture, the anatomy of the articular surface needs
restoration to avoid early osteoarthrosis. The most common fixation technique employs
metal screws. Despite being efficient and widely used, the screws have to be removed
in a second surgical procedure. To overcome this issue, bioabsorbable synthetic materials
have emerged for fragment fixation. However, these materials are not widespread and
can generate a foreign body reaction.[4]
The fixation technique with bone sticks has already been used as a form of fixation
in osteochondritis dissecans of the knee, and numerous studies have proven the good
bone consolidation provided.[6]
[7] The sticks are made from cortical bone, usually from the tibia. The number of sticks
used for fixation in osteochondritis dissecans is variable; some studies report an
average of 3 to 4 sticks per lesion,[8] while others describe 4 to 6.[7]
In the present case report, we selected five rectangular bone sticks. The incompatibility
between the circular hole and the square stick ensures a firmer fixation.[8] Bone sticks can be described as autologous bone grafts. Thus, for fracture consolidation,
they have osteoconductive and osteoinductive properties.[9]
The advantage of using bone sticks to fix osteochondral fragments in the knee is allowing
fracture fixation in a single surgery with no risk of a foreign body reaction. Despite
the short follow-up period and the lack of histological follow-up of the lesion, imaging
tests, and the patient's complete physical rehabilitation demonstrate that fixation
of the osteochondral fragment of the knee with bone sticks is an effective technique.
