Definition of the Disease. Causes of the Condition
Osgood-Schlatter disease is inflammation of the tissues in the upper part of the tibia, which develops in children and adolescents.
Osgood-Schlatter disease affects the patellar tendon where it attaches to the prominence of the tibia. It is quite common in teenagers, especially young athletes. The main symptom is knee pain, which can last from several weeks to months.
Prevalence of Osgood-Schlatter Disease
It usually develops in children during the active bone growth period, i.e., during a growth spurt: in boys aged 10–15 years, and in girls aged 8–12 years. The disease occurs in 20% of young athletes and 5% of adolescents who do not participate in sports, with boys being more affected. In 25% of cases, both knees are involved in the pathological process, although the disease is usually asymmetrical.
Causes of Osgood-Schlatter Disease
Among the main causes of the disease are:
- Intensive sports activities involving frequent knee bending, such as basketball, volleyball, sprinting, gymnastics, and soccer.
- Frequent knee bending activities such as walking, running, squats, kneeling, jumping rope, climbing trees and turnstiles.
- Congenital anomalies of the patella and its ligaments, such as high attachment of the patellar ligament or its attachment to a broad area of the tibia, and high patellar standing.
- History of Shin splints.
- Genetic predisposition to high patellar standing and hypermobility syndrome (increased joint mobility).
Injury to knee ligaments, dislocation, fractures of the tibia and patella, or chronic knee micro-traumas cannot cause Osgood-Schlatter disease, as it develops due to frequent loads.
Main Risk Factors:
- Age 9–14 years.
- Male gender.
- Excessive physical exertion.
- Rapid growth spurt.
Symptoms of Osgood-Schlatter Disease
Among the main symptoms are:
- Dull pain just below the knee, especially during jumps and stair climbing.
- Tenderness around the tibial tubercle during walking, running, and jumping.
- Limping while walking.
- Pain when kneeling.
- Heat in the knee joint.
- Tenderness when touching the tibial tubercle.
- Swelling below the kneecap and around the tibia.
Initially, the pain is mild and only occurs during intense activity, but over time it intensifies and sometimes bothers the patient even at rest. Swelling may later accompany the pain, interfering with the patient’s normal activities. Patients typically seek medical attention when the pain becomes intense (rated 5 out of 10 on a pain scale).
Usually, the disease does not limit knee movement, but pain occurs at the patellar ligament attachment site during bending. If the thigh muscle is tense and shortened, the knee joint may not fully bend, causing painful sensations on the front surface of the thigh.
Symptoms worsen during sports activities involving jumping or pressure on the knees. Pain increases during walking, bending and straightening the legs, or climbing stairs, but may subside at rest. The disease usually resolves on its own after age 16, when growth plates close.
Classification and Stages of Osgood-Schlatter Disease
In Osgood-Schlatter disease, there are 3 types of avulsion fractures:
1. Type I: The fragment is slightly displaced. The patient experiences moderate pain (3–4 out of 10 on a pain scale) during sports activities. Surgery is not required; conservative treatment is sufficient, such as avoiding knee flexion, taking nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief, reducing physical activity, adjusting diet, and increasing vitamin D intake.
2. Type II: A small avulsion in the area of the tibial tubercle. The patient complains of moderate pain (5–6 points) during sports activities and active games, with pain persisting even after activity. If NSAIDs do not provide relief, surgery may be necessary.
3. Type III: Avulsion of the tibial tubercle apophysis. In this case, conservative treatment is ineffective, so surgery is required. The patient experiences moderate pain (5–6 points) with minimal exertion, such as a 15-minute walk or active games. The patient may be able to bear weight on the leg, but the pain persists even after taking pain relievers. There are no traumas or extensive hematomas at the site of the patellar ligament attachment.
The disease is characterized by 3 severity stages:
- – Acute stage: The edges of the patellar ligament become blurred due to soft tissue swelling. After 3–4 months, the tuberosity changes shape, and the necrotic areas begin to resorb.
- – Subacute stage: Soft tissue swelling resolves, but changes in the tuberosity remain.
- – Chronic stage: The bone fragment may fuse with the normal part of the tuberosity.
Complications of Osgood-Schlatter Disease
Frequent bending of the knee joint can lead to the formation of a palpable hard lump in the area of the tibial tuberosity. Besides the protrusion, the patient may not experience any other discomfort.
Osgood-Schlatter disease leads to remodeling of the tuberosity, instability of the knee joint, and tension in the leg’s soft tissues, resulting in knee pain in adulthood.
If treatment for the acute stage is not initiated promptly, a part of the bone may detach. Avulsion fracture is accompanied by sharp pain in the knee joint, swelling, and hematoma.
Diagnosis of Osgood-Schlatter Disease
Diagnosis primarily relies on the clinical presentation, physical examination, and X-rays in two projections, followed by additional diagnostic methods.
History Taking and Examination
A doctor may suspect Osgood-Schlatter disease if the patient complains of knee pain during walking and sports activities. The doctor inquires about:
- Patient’s age.
- Onset of pain.
- Use of pain relievers by the patient.
- Frequency and type of sports activities.
- History of injuries in the past year.
During the examination, the doctor pays attention to swelling and tenderness around the tibial tuberosity. The patient experiences knee pain when extending the knee against resistance and tension of the quadriceps muscle or when squatting with a fully flexed knee.
Straight leg raise is usually painless. If pain occurs in the patellar tendon rather than the bony prominence, it indicates patellar tendonitis (jumper’s knee).
The Ely test is conducted with the patient lying on their stomach. In this position, flexing the knee also flexes the hip joint. In a healthy individual, this movement does not cause discomfort, but in a patient with Osgood-Schlatter disease, there is pain in the muscles of the anterior thigh.
During the examination, the doctor also observes shortening of the infrapatellar tendons and tension in the quadriceps muscle, assesses the range of motion of the hip to ensure that knee pain is not associated with other pathology (e.g., slipped capital femoral epiphysis, Legg-Calve-Perthes disease).
Instrumental Diagnosis
The primary method of instrumental diagnosis is X-ray of the knee joints in two projections, which allows visualization of structural changes in the tuberosity.
Fragmentation with detachment of a bone fragment is best seen on lateral X-rays.
Additional diagnostic methods include:
- Ultrasound of the knee joint: provides comprehensive information about the condition of the patellar ligament, tuberosity involvement, and surrounding soft tissues. Ultrasound is also suitable for periodic monitoring of the disease. Sometimes ultrasound is performed before X-rays, but it is less informative.
- Multislice computed tomography (MSCT): sectional X-ray of bone structures. Describes the condition of the tuberosity. On the images, the doctor examines the bone condition of the patella and the upper part of the tibia. It is possible to make a 3D image of the bone. MSCT is performed if there is suspicion of tuberosity fragmentation or detachment of part of the bone.
- Magnetic resonance imaging (MRI): the only method for diagnosing the condition of soft tissue structures of the knee joint: muscles, tendons, and ligaments. The doctor evaluates the condition of the tuberosity, swelling of the patellar ligament, meniscal damage, and the presence or absence of free fluid in the knee joint cavity. MRI is prescribed for knee joint swelling and pain at rest. This method allows excluding internal knee joint injuries (damage to cruciate ligaments, menisci, collateral ligaments of the knee joint, changes in Hoffa’s body).
Differential Diagnosis
Osgood-Schlatter disease is differentiated from:
– Bone tumors: Pain occurs at night and rarely in the area of the tibial tuberosity, and it is not associated with activity.
– Patellar tendonitis: Characterized by a dull pain in the area of the patellar tendon, usually occurring in the evening.
– Osteomyelitis of the tibia: Fever increases, and night pain unrelated to activity occurs.
– Perthes disease: Pain is felt throughout the leg, but X-rays show no abnormalities. Changes in the heads of the femur bones are visible on pelvic X-rays.
– Synovial fold injury: The knee joint swells and does not fully bend, accompanied by a dull pain unrelated to activity.
– Infectious apophysitis: Fever increases, the knee joint becomes red, and pain persists throughout the day even without activity.
Treatment of Osgood-Schlatter Disease
Osgood-Schlatter disease resolves on its own as the skeleton matures. To alleviate pain, conservative treatment is prescribed, which helps approximately 90% of patients. In other cases, surgery is performed.
Conservative Treatment
Patients are advised to:
– Avoid physical activities.
– Perform special stretching exercises for the muscles of the anterior thigh.
– Use nonsteroidal anti-inflammatory drugs (NSAIDs) or apply ice for 5–7 minutes in case of swelling and severe pain (the ice pack should be wrapped in a towel and applied to the painful area).
– Undergo shock wave therapy for persistent pain and absence of bone fragmentation on X-rays.
– Avoid squatting and kneeling until the symptoms of the disease subside.
– Continue sports activities if the pain is tolerable and subsides within a day after training.
If all the above methods of pain management are ineffective, surgery is recommended.
Surgical Treatment
Surgical procedures include open and arthroscopic techniques.
Advantages of arthroscopy over open surgery:
– Minimal risk of patellar tendon damage.
– Faster recovery.
– Absence of scar tissue on the tuberosity, which would cause pain when pressure is applied to the knee.
– No scars.
During arthroscopy, the doctor makes a puncture in the skin with the knee extended and removes bone fragments from the soft tissues.
During the rehabilitation period, patients are recommended to undergo physiotherapy and engage in therapeutic exercises, after which they can return to a full training regimen.
Open surgery is performed for other knee joint injuries or in case of purulent complications after arthroscopy.