Introduction:
A fracture to the tibial tubercle or tuberosity fracture is called a tibial tubercle fracture. It is a type of avulsion fracture. Avulsion injury or fracture is when a ligament, tendon, or muscle attachment is pulled off along with a fragment of cortical bone.
Where Is the Tibial Tubercle Located?
The tibial tuberosity is a large protrusion just below the junction of both medial and lateral tibial condyles on the tibial bone. It is palpated as a protrusion inferiorly to the patella or the knee cap. The tibia bone is the longest and is also called the shin bone. The tibial tuberosity is the terminal part of the tibia, the weight-bearing bone that provides stability.
How Is the Tibial Tuberosity Formed?
The tibial tuberosity forms in four stages:
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1st Stage - Cartilaginous stage begins by the 15th week of gestation (pregnancy).
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2nd Stage - Apophyseal stage begins between 8 to 12 years in females and 9 to 14 years in males.
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3rd Stage - The epiphyseal stage is the merging of apophysis and epiphysis, seen around 10 to 15 years in females and 11 to 17 years in males.
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4th Stage - Bony fusion is seen in females around 14 to 15 years and males by 16 to 17 years.
The growth plate thus closes at the late pubertal stage and predisposes to injuries due to weak tensile strength of the muscles.
What Are the Types of Tibial Tubercle Fractures?
A fracture to the tibial tubercle or tuberosity fracture is called a tibial tubercle fracture. It is a type of avulsion fracture. Avulsion injury or fracture is when a ligament, tendon, or muscle attachment is pulled off along with a fragment of cortical bone.
Tibial tubercle fracture classification (Ogden classification) is based on the following:
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The extension of the fracture to the secondary ossification center (Type I).
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Those involving portions of primary and secondary ossification centers (Type II).
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Those crossing both primary and secondary ossification centers (Type III).
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Extends to proximal tibial physis (Type IV).
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Those having avulsion due to the extensor mechanism (Type V).
The primary ossification center is where the bone formation begins, and secondary ossification is the area following the primary center, usually at the edges of the bones.
What Are the Causes of Tibial Tubercle Fractures?
Tibial tubercle fractures are rare, seen commonly in adolescents (around the age of 12 to 15 years), and are known to be injuries associated with sports like volleyball, football, basketball, running, and long jump. Males are more prone to such fractures than females, as males have increased quadriceps muscle strength. Injury is usually caused by the contraction of quadriceps muscles during a knee extension, like initiating a jump or landing, when the knee muscles flex to absorb the impact.
What Are the Features of Tibial Tubercle Fracture?
Symptoms include:
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Sudden onset of severe knee pain following a jump.
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Severe swelling of the knee is called knee effusion.
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Inability to move or extend the knee or walk.
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A popping sound was heard at the time of injury.
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Bleeding in the joints is called hemarthrosis.
How Is the Fracture Diagnosed?
The fracture requires immediate attention as soon as possible since it can increase the severity of the pain and lead to complications. The doctor initially examines the site for the extent of the injury and palpates to record the tenderness in the area, advises an X-ray, both anteroposterior and lateral views, and prescribes medications to relieve pain, such as Acetaminophen, Ibuprofen, etc. X-ray depicts the level of displacement of the fracture or the level of separation of the broken fragments. A computerized tomography (CT Scan) or magnetic resonance imaging (MRI) is advised in severe cases.
What Are the Complications of This Fracture?
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Repeated trauma or a chronic injury at the insertion of the patellar tendon onto the tibial tubercle can lead to severe pain in the tibial tubercle, called Osgood Schlatter disease.
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Complex tibial tuberosity fractures or a delay in diagnosis and treatment can cause popliteal artery damage, leading to deep vein thrombosis.
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Swelling when left untreated or injury to the anterior tibial artery can lead to increased pain, pressuring the muscles and nerves, decreasing the oxygen supply, and leading to compartment syndrome.
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Type III fractures can be associated with tearing the meniscus or gelatinous cartilage, called a meniscal injury.
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Injury or tearing of the anterior cruciate ligament.
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Recurvatum is a deformity that occurs after the tibial tubercle avulsion due to the closure of the anterior physics while the growth continues at the posterior physics.
How Are Tibial Tuberosity Fractures Treated?
Treatment of tibial tuberosity fractures depends on the location of the fracture line, displacement, and severity.
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Mild to moderate tibial tuberosity or non-displaced fractures are treated by conservative therapy, and severe fractures need surgical management.
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Type I fractures or minimal displacement fractures less than 2 mm are treated by nonoperative methods. The conservative method is also advised for small children, which includes immobilization with a cylinder cast or long leg cast for around four to six weeks, after which an X-ray is taken to confirm the union of the bone. After the bony union is achieved, it is followed by physical exercises.
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Open reduction or surgery is the treatment of choice in case of severe or displaced fractures. Type II to type V fractures are treated by open reduction and internal fixation (ORIF). A midline incision is given at the fracture site, and the area is cleaned to remove the debris. Internal fixation is done using implants or screws to achieve compression. After the surgery, the area is immobilized with a long leg cast for four to six weeks, followed by a hinge brace fixation.
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Alternatively, arthroscopy or arthrotomy is used to achieve an anatomical reduction in cases where soft tissues are involved in fracture.
Post-operative Measures to Be Taken After the Surgery
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Taking the medications at the appropriate time.
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Maintaining a healthy lifestyle and weight management.
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Regular intake of calcium and vitamin D supplements.
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Doing physical exercises will strengthen the muscles and increase their stability.
Conclusion:
Tibial tubercle fractures are commonly seen in adolescents and are mainly caused due to sports injuries. It is associated with severe pain and swelling and is usually managed by closed reduction and complex cases by surgical management. Tibial tubercle fractures, being rare, are usually treated successfully, and with proper care and evaluation, the patient can recover back to normal in a few months.
