Apophysitis

Cite this article as:
Stephen Gilmartin. Apophysitis, Don't Forget the Bubbles, 2020. Available at:
https://doi.org/10.31440/DFTB.24364

David is a 12-year-old boy who attends the emergency department complaining of bilateral heel pain. His pain has been getting gradually worse over the past month. He is a keen footballer, but his symptoms have gotten to the stage where he is now unable to play through his pain.

 

Apophysitis is a term used to describe a group of overuse traction injuries which commonly cause pain in adolescents. We have all heard of Osgood Schlatter disease. It is the most common form of apophysitis. Other anatomical areas that are commonly affected include the inferior pole of patella (Sinding-Larsen-Johansson), calcaneal tuberosity (Sever’s), medial epicondyle of the elbow (within spectrum of Little League elbow) and various sites on the pelvis. They’re subtly different from osteochondrosis, which is instead due to changes in the epiphyseal ossification centre.

An apophysis is an area of bony growth separate to the ossification centres. It acts as a site of tendon or ligament attachment and will eventually fuse with the bone as the body matures. Rapid growth and relative bone weakness combined with repetitive movements cause increased traction forces at the point of attachment. The apophysis is the weakest point in the muscle-tendon-bone junction; repeated strain at this point leads to bone fragmentation and micro-separation. This abnormal growth leads to swelling and pain at the site. Similar overuse injuries result in tendon and muscle injuries in adults.

Apophysitis is most common during ages of peak growth i.e. between 10-14 years in girls and 12-16 years in boys. Apophysitis is traditionally more common in boys, but the incidence is growing in girls. This is likely linked to increasing sports participation rates among girls of this age. The mean age of onset is younger in girls due to the earlier appearance of the ossification centres. Earlier fusion leads to the cessation of symptoms at a younger age in girls when compared to boys. In lower limb apophysitis, up to 50% of patients will experience bilateral symptoms.



 

Let’s take a look at some x-rays

This 11-year-old male basketball player has been complaining of heel pain. His ankle x-ray shows increased density of the calcaneal apophysis, typically seen in children between 7 and 14 years with Sever’s Disease. There is loss of fat/soft tissue planes in the region of the retrocalcaneal bursa in keeping with acute inflammation.

Case courtesy of Dr Dinesh Brand, Radiopaedia.org. From the case rID: 60324

 

This 12-year-old female long-distance runner complains of anterior knee pain, localised to the inferior aspect of her patella. Her lateral knee x-ray shows dystrophic ossification of the inferior patella with subtle thickening of proximal patellar tendon. These changes are consistent with a diagnosis of Sinding-Larsen-Johansson.

Sinding-Larsen-Johansson. Case courtesy of Dr Michael Sargent, Radiopaedia.org. From the case rID: 6323

 

This 13-year-old female volleyball player presents with progressive pain over her tibial tuberosity. Her pain is exacerbated by jumping. Her lateral knee x-ray shows fragmentation of apophysis with overlying soft tissue swelling, classic for Osgood Schlatter Disease. Some isolated fragmentation can be normal at the tibial tuberosity.

Osgood Schlatter’s Disease. Case courtesy of Dr Hani Salam, Radiopaedia.org. From the case rID: 9740

 

This 11-year-old boy presents to the ED with worsening elbow pain. He is an avid cricket player and is trying to make his county underage team but finds his pain much worse while bowling. His AP elbow x-ray shows widening of the physis at the medial epicondyle. This is consistent with a diagnosis of Little League Elbow. You may also see fragmentation.

Little League Elbow from Orthobullets

 

This is an MRI of a 14-year-old male long-distance runner complaining of anterior hip pain. His pain is becoming increasingly worse on running and is now affecting his times. MRI shows bone marrow and surrounding soft tissue oedema at the anterior superior iliac spine involving the sartorius muscle origin without separation as may occur in an acute avulsion injury. This is consistent with ASIS (anterior superior iliac spine) apophysitis. Plain radiographs are usually normal or may only show subtle changes of pelvic apophysitis.

ASIS apophysitis. Case courtesy of Dr Chris O’Donnell, Radiopaedia.org. From the case rID: 31877

 

History and exam

Apophysitis has a typical history and the diagnosis is largely based on an accurate history and exam. An adolescent will present with gradual onset focal pain over the involved site. They are typically highly active and may be going through an acute increase in there training levels. They may be currently progressing to higher levels of sport or competing in multiple sports at multiple grades. The initial symptom will be pain present at the start of physical activity. In the early stages the pain will often subside once the child has fully warmed up, only to return once they have cooled down. As the process progresses the child will have persisting symptoms throughout physical activity and the pain will eventually result in total cessation of activity.

Clinical examination will reveal point tenderness over the affected site. There may be mild swelling over the area. Pain will be reproduced by resisted contraction of the affected muscle, e.g. resisted plantar flexion of the ankle in Sever’s disease and resisted knee extension in Osgood-Schlatter’s. A good way to assess this is to ask the patient to demonstrate actions which exacerbate their pain.

 

Differential diagnosis

Alternative diagnoses and investigations should be considered if there are any concerning features on history or exam. Atypical features on presentation are:

  • Sudden onset pain
  • Pyrexia
  • Non-weightbearing
  • History of trauma
  • Point of tenderness or age of patient not typical for apophysitis.

The most common differential diagnoses are osteomyelitis, avulsion fractures, osteochondritis, stress fractures and malignancy. Investigations should be performed in accordance with suspected differential diagnosis.

The below cases and accompanying images highlight the need for you have possible alternative diagnoses in the back of your mind. The patient should be presenting with gradual onset pain, over an apophysis site, at the appropriate age (10-16) for apophysitis. A history which includes high levels or sudden increase in activity can be helpful. Any atypical features should be actively sought out.

 

This elbow x-ray is from a 13-year-old male baseball pitcher attending with sudden onset medial elbow pain. The medial epicondyle is displaced with a sliver adjacent bone, representing a medial epicondyle avulsion fracture. There is marked adjacent soft tissue swelling and joint effusion. Compare this to the Little League elbow x-ray.

Medial epicondyl avulsion fracture. Case courtesy of Dr Henry Knipe, Radiopaedia.org. From the case rID: 41533

 

A 10-year-old female basketball player attended with sudden onset knee pain following a fall. The x-ray shows a bone fragment avulsed from inferior patella at point of tendon insertion with moderate overlying soft tissue swelling: a patella sleeve fracture. This contrasts with the findings of dystrophic ossification of Sinding-Larsen-Johansson.

Patella sleeve fracture. Case courtesy of Dr Yuan Ling, Radiopaedia.org. From the case rID: 69680

 

A 13-year-old female long jumper attends with anterior knee pain following a fall resulting in forced flexion of their flexed knee. She has significant pain and is unable to straight leg raise. Her x-ray shows displacement of tibial tuberosity with significant overlying soft tissue swelling: an avulsion fracture of the tibial tuberosity. Compare this to the typical radiographic features of fragmentation and mild swelling observed in Osgood-Schlatter disease.

Tibial tuberosity avulsion fracture. Case courtesy of Radiopaedia.org. From the case rID: 12022

 

A 13-year-old girl presents with worsening ankle/heel pain over the last week. Her pain is exacerbated on while running and playing football. She has been pyrexic over the past 24 hours and is now unable to weight bear. The x-ray of her ankle shows diffuse soft tissue swelling abutting the distal end of her fibula. There is suspicious erosion of distal fibular cortex. These findings are suspicious for osteomyelitis of the distal fibula.

Osteomyelitis of the distal fibula. Case courtesy of Dr Maulik S Patel, Radiopaedia.org. From the case rID: 10046

 

An 8-year-old boy attends with gradual onset knee pain while running. He begins to notice some associated swelling. His mother feels he is becoming increasingly lethargic. Lateral x-ray shows sclerotic lesion involving the dia-metaphyseal region of the tibia with a wide zone of transition and characteristic “Sunburst ” type of periosteal reaction seen in osteosarcomas.

Osteosarcoma of the tibia. Case courtesy of Dr Iqbal Naseem, Radiopaedia.org. From the case rID: 22814

 

Investigations

Despite the diagnosis being clinical, a baseline x-ray is often useful. An x-ray can help ensure there is no avulsion fracture and a study by Rachel et al found x-rays changed management in up to 5% of patients with Sever’s disease.

Findings of apophysitis can vary on imaging and some patients may not show any radiological changes on plain films. The typical x-ray findings include increased density and fragmentation at secondary ossification centres. Overlying soft tissue swelling can often be seen. MRI will reveal increased fluid signal, apophyseal oedema and fragmentation.

This lateral plain film view shows the calcaneal apophysis with high density and fragmentation consistent with Sever’s disease.

Sever’s on x-ray. Case courtesy of Dr Fateme Hosseinabadi , Radiopaedia.org. From the case rID: 69971

Compare the x-ray to this MRI image showing oedema and fragmentation at the calcaneal apophysis and extending into the adjacent calcaneal tuberosity. These findings are commonly seen in patients with Sever’s disease.

Sever’s on MRI. Case courtesy of Dr Paulo A Noronha, Radiopaedia.org. From the case rID: 63302

 

Treatment

Apophysitis is a self-limiting process. Most patients will return to full activity following 4-6 weeks of rest or reduced activity. Despite successful return to activity, patients may continue to experience some symptoms. The symptoms will cease definitively once growth centres fuse.

The focus of treatment should be to reduce symptoms sufficiently to allow continued sports participation.

Strategies shown to improve recovery are

  • analgesia
  • activity modification
  • muscle stretching and strengthening programmes

Other therapies which have little evidence but may be helpful in some cases include

  • ice application
  • foot orthotics or heel raises in Sever’s disease
  • taping or bracing

There is no place for surgery in the standard treatment of apophysitis. Any short-term benefit observed from surgery cannot be justified when weighed against the potential damage to an immature skeleton. Surgery may be considered an option if there is a displaced avulsion fracture or a loose body in an affected joint.

 

Prevention

Apophysitis is a largely preventable process and as a result recent focus has been placed on both primary and secondary prevention programmes. It can be difficult at an individual level to make changes as these patients tend to be highly active and competitive people. This has seen some youth sport bodies enforcing limits on game participation and mandatory rest to avoid repetitive strain.

Simple advice to give parents and children include:

  1. Encourage 1-2 days off from competitive sport per week
  2. Encourage 2-3 months off from each sport per year
  3. Participate on only one team per sport
  4. Avoid early sport specialisation
  5. Avoid increasing levels of training by more than 10% from one week to the next
  6. Maintain good sleep, hydration and dietary habits.

 

Take home tips

  • Apophysitis has a typical history of gradual onset pain over an apophysis in highly active adolescents.
  • It is a self-limiting process but can cause debilitating pain.
  • Treatment should focus on analgesia, activity modification and muscle stretching programmes.
  • Symptoms will resolve definitively once ossification centres fuse.

 

Not to miss bits

  • Any atypical features should be investigated appropriately. The area around the apophysis is a common site for avulsion fractures, osteomyelitis and malignancy.
  • These patients are high risk for other overuse injuries. All patients should be given secondary prevention advice.

 

And our favourites, the controversies

  • Despite the diagnosis being clinical, baseline x-rays can be useful to out-rule other differential diagnoses.
  • There is little evidence displaying additional benefit for treatment with taping or splints.
  • Custom orthotics can be useful for patients suffering from Sever’s Disease.

 

David undertook a month long physio led programme of activity modification and muscle stretching. He was given secondary prevention advice to avoid overtraining. He is now back to symptom free football participation.  

 

References

Brenner, J. S. (2007). Overuse Injuries, Overtraining, and Burnout in Child and Adolescent Athletes. Pediatrics, 119(6), 1242 LP – 1245

Elengard, T., Karlsson, J., & Silbernagel, K. G. (2010). Aspects of treatment for posterior heel pain in young athletes. Open Access Journal of Sports Medicine, 1, 223–232.

Fleisig, G. S., Andrews, J. R., Cutter, G. R., Weber, A., Loftice, J., McMichael, C., Hassell, N., & Lyman, S. (2011). Risk of serious injury for young baseball pitchers: a 10-year prospective study. The American Journal of Sports Medicine, 39(2), 253–257.

Frush, T. J., & Lindenfeld, T. N. (2009). Peri-epiphyseal and Overuse Injuries in Adolescent Athletes. Sports Health, 1(3), 201–211.

Gregory, B., & Nyland, J. (2013). Medial elbow injury in young throwing athletes. Muscles, Ligaments and Tendons Journal, 3(2), 91–100.

Guldhammer, C., Rathleff, M. S., Jensen, H. P., & Holden, S. (2019). Long-term Prognosis and Impact of Osgood-Schlatter Disease 4 Years After Diagnosis: A Retrospective Study. In Orthopaedic Journal of Sports Medicine (Vol. 7, Issue 10, p. 2325967119878136).

James, A. M., Williams, C. M., & Haines, T. P. (2013). “Effectiveness of interventions in reducing pain and maintaining physical activity in children and adolescents with calcaneal apophysitis (Sever’s disease): a systematic review.” Journal of Foot and Ankle Research, 6(1), 16.

Rachel, J. N., Williams, J. B., Sawyer, J. R., Warner, W. C., & Kelly, D. M. (2011). Is Radiographic Evaluation Necessary in Children With a Clinical Diagnosis of Calcaneal Apophysitis (Sever Disease)? Journal of Pediatric Orthopaedics, 31(5).

Ramponi, D. R., & Baker, C. (2019). Sever’s Disease (Calcaneal Apophysitis). Advanced Emergency Nursing Journal, 41(1), 10–14.

Vaishya, R., Azizi, A. T., Agarwal, A. K., & Vijay, V. (2016). Apophysitis of the Tibial Tuberosity (Osgood-Schlatter Disease): A Review. Cureus, 8(9), e780–e780.

Wiegerinck, J. I., Zwiers, R., Sierevelt, I. N., van Weert, H. C. P. M., van Dijk, C. N., & Struijs, P. A. A. (2016). Treatment of Calcaneal Apophysitis: Wait and See Versus Orthotic Device Versus Physical Therapy: A Pragmatic Therapeutic Randomized Clinical Trial. Journal of Pediatric Orthopaedics, 36(2).

Cairns G, Owen T, Kluzek S, et al. Therapeutic interventions in children and adolescents with patellar tendon related pain: a systematic review. BMJ Open Sport & Exercise Medicine 2018

Cairns, G., Owen, T., Kluzek, S., Thurley, N., Holden, S., Rathleff, M. S., & Dean, B. J. F. (2018). Therapeutic interventions in children and adolescents with patellar tendon related pain: a systematic review. BMJ Open Sport &Amp; Exercise Medicine, 4(1), e000383.

 

Proximal Tibial Fractures

Cite this article as:
Deirdre Glynn. Proximal Tibial Fractures, Don't Forget the Bubbles, 2019. Available at:
https://doi.org/10.31440/DFTB.20257

Proximal tibial fractures are infrequent in children relative to tibial shaft and distal tibial fractures. The patterns of injury correspond to the age of the child and the type of force involved.

Tibial physeal fractures

A 13-year-old boy is brought into ED by ambulance following a motor vehicle accident. He was a front street restrained passenger in a car that was involved in a head-on collision with another car. His knee was hyperextended on impact and he presents with an acutely painful and swollen knee.

Proximal tibial physeal fractures occur in young adolescents (12-14 years), usually from high energy mechanisms such as sports injuries and road traffic accidents. Patients present unable to weight bear with a swollen, tender knee and a marked decrease in range of movement. It is really important to assess the limb’s neurovascular status as rarely posterior displacement of the fracture may injure the popliteal artery. These patients are also at risk of developing compartment syndrome so make sure you frequently reassess of the limb and the child’s pain in the acute setting.

Confirm diagnosis with AP and lateral radiographs of the lower leg including the knee and ankle. Proximal tibial physeal fractures are classified according to the Salter-Harris system.

Tibial plateau fractures

The initial treatment of closed proximal tibial fractures that are neurovascularly intact is analgesia and immobilisation in an above knee back slab or splint. If the patient has vascular compromise then they need an urgent ortho review and reduction.

Further treatment depends on the severity of the fracture and the degree of displacement. Generally speaking non-displaced Salter Harris I or II fractures can be treated non-operatively with 4-6 weeks of non-weight bearing and leg immobilisation in slight flexion. Displaced fractures and all Salter-Harris III, IV or V fractures need prompt ortho review and likely operative repair.

Serious acute complications are rare. These include arterial injury, nerve injury and compartment syndrome. The most serious long-term complication is growth arrest and resultant leg length discrepancy, which happens in up to 25% of cases. Therefore all physeal fractures need ortho follow up.

Tibial spine fractures

A 12-year-old girl presents with knee pain, decreased range of movement and swelling following a fall from her bicycle. As she fell she recalls hyperextending and twisting her knee.

Case courtesy of Dr Adam Tunis, Radiopaedia.org. From the case rID: 42621 Tibial spine avulsion (and associated Segond fracture)

Fractures of the tibial spine or eminence are avulsion fractures at the insertion of the anterior cruciate ligament (ACL). They are uncommon and typically occur in adolescents between the 8-14 years of age. They are usually associated with a fall from a bicycle or pivoting on a planted foot while playing sport. It is equivalent to mid-substance rupture of the ACL in adults. With stress, the incompletely ossified tibial eminence in the child avulses before the ligament ruptures.

These patients usually presents with painful haemarthrosis and are unable to fully extend the knee. Stability may be difficult to assess due to pain and muscle spasm but the anterior drawer and Lachman’s test may be positive. AP and lateral x-rays of the knee should be obtained. Complicated fractures will likely need further evaluation with CT or MRI to fully characterise the injury.

Fractures are identified as type I, II, and III by the Meyers and McKeever classification. Type I fractures are non or minimally displaced. Type II fractures are displaced anteriorly with an intact posterior hinge. Type III fractures are completely displaced from the proximal tibia. This classification system had been modified by Zaricznyj to include type IV/Comminuted fractures. (Zaricznyj 1977).

Immediate treatment in ED should be with appropriate analgesia and splinting the knee in extension. Displaced fractures may need operative repair. All patients will need to be followed by in orthopaedic clinic.

Complications are not uncommon and include pain, malunion, non-union, severe laxity and arthrofibrosis.

Metaphyseal corner fractures

A 2-year-old boy is brought to the ED by his concerned aunt. She has noticed over the last few days that he is reluctant to weight bear on his left leg and appears to have a painful knee.

Case courtesy of Dr Hani Salam, Radiopaedia.org. From the case rID: 13614

Metaphyseal corner fractures, or bucket handle fractures occur in children less than two years old. In a previously well infant with normal bones this fracture is almost pathognomonic for non-accidental injury (NAI). These fractures are Salter Harris II fractures of the long bones and are most frequently seen in the proximal or distal tibia, distal femur or proximal humerus. They result from shaking or twisting injuries.  If there is no sign of neurovascular compromise management is conservative and should focus on pain control and a period of immobilisation in plaster. As the diagnosis is highly suggestive of non-accidental injury the child should be referred through regular safeguarding pathway.

Tibial tubercle avulsion fractures


A 15-year-old boy presents with acute onset severe knee pain following landing heavily while playing basketball. The joint is swollen, he is unable to actively extend the knee and he is exquisitely tender over the tibial tuberosity.

Tibial tubercle fractures are uncommon and usually occur in boys between the ages of 13 and 16 years. The mechanism is usually forced flexion of the knee during active quadriceps contraction e.g. landing a jump while playing basketball.

Acute tibial tubercle apophyseal fractures are different from tibial tubercle apophysitis (Osgood Schlatter disease – see below) which has gradual onset.

Patients presents with acute onset pain with swelling and tenderness over the tibial tubercle with limited knee extension, proximal displacement of the patella and shortening and spasm of the quadriceps muscle.

Diagnosis is confirmed on lateral knee x-ray, which demonstrates a fracture through the base of the tubercle. The fracture fragment is proximally displaced and remains attached to the patellar tendon.

There are several classification systems described. Watson-Jones classified the fracture in to three types .

  • Type 1: The fracture is within the most distal portion of the tibial tuberosity with resultant avulsion of the most distal part.
  • Type 2: The fracture line extends through the cartilage bridge to the proximal end of the tibia but doesn’t involve the articular surface.
  • Type 3: The fracture line extends to the articular surface of the proximal tibia.

Ogden modified this classification system to include subtypes A and B to indicate if the fracture is comminuted or not.

Initial management of a tibial avulsion fracture without neurovascular compromise, is pain control, immobilisation of the fracture, and reduction of swelling. Type IA injuries are treated conservatively with knee immobilisation in full extension.  Patients should remain non-weight-bearing. Type IB, type II, and type III injuries are generally treated with open reduction and internal fixation (ORIF).  All patients need a variable period of immobilisation (average four weeks). Progressive rehab of the quads will be needed afterwards. Return to play can be expected approximately two to three months after type I and II injuries and at three to six months after type III injuries.

Acute compartment syndrome, the most serious complication associated with tibial tubercle fracture, is rare. Due to its potential catastrophic consequences it is important to repeatedly assess the neurovascular status of the limb in the acute phase with onward urgent orthopaedic referral if needed. More common complications include bursitis, ongoing tenderness or prominence of the tibial tuberosity, mal or non-union and re-fracture.

Osgood-Schlatter disease

A 12-year-old keen footballer, presents with her father complaining of several months of anterior knee pain that is worse during and after exercise. Recently she has noticed a prominent bump to the front of her knee.

Osgood-Schlatter disease, also known as osteochondritis or apophysitis of the tibial tubercle, is a common cause of anterior knee pain in adolescents. It is an overuse injury caused by repetitive strain and chronic avulsion of the secondary ossification centre (apophysis) of the tibial tubercle at the insertion point of the patellar tendon. It is more common in boys and affects up to 10% of athletic adolescents. It occurs in children aged 9 -14 years who have undergone a rapid growth spurt. It’s typically unilateral but can be bilateral in 20-30% of cases.

It occurs more frequently in children who play sports that place stress on the tibial tubercle through repetitive quadriceps contraction e.g. football, basketball, sprinters, gymnastics and dance. The patient generally presents with a history of non-traumatic gradual onset anterior knee pain associated with tenderness and swelling over the tibial tubercle. Symptoms are exacerbated by exercise and kneeling and relieved by rest.

Exam findings include tenderness and soft tissue or boney prominence of the tibial tubercle. Pain is reproducible with resisted knee extension.  Straight leg raise is usually painless and range of motion of the knee is not affected.

Osgood-Schlatter disease is a clinical diagnosis. Imaging is not necessary to confirm the diagnosis in cases where the presentation is characteristic. If knee x-ray is done it may be normal or show anterior soft tissue swelling or fragmentation of the tibial tubercle, Occasionally a persistent bony ossicle may be visible after fusion of the tibial epiphysis.   Imaging may be needed as part of the work up in patients with atypical symptoms and signs.

Consider other diagnoses, investigation, and onward referral in the presence of trauma, knee erythema, systemic symptoms, bone or joint pain elsewhere, night pain, rest pain or painful examination of the hip or knee joint. 

Osgood-Schlatter disease is usually a benign and self limiting condition. Symptoms generally resolve once the growth plate is ossified. Conservative measures are the mainstay of treatment and include:

  • Continued sports participation is recommended providing pain is tolerable and resolves within 24 hours. Otherwise a graded reduction in activity may be sufficient to control the pain.
  • Simple analgesia and application of ice for pain control.
  • Physiotherapy that includes stretching and strengthening of the quadriceps and hamstrings.
  • Corticosteroids, crutches and knee immobilisers are not recommended.
  • Specialist referral is indicated for severe cases or where symptoms remain intolerable into adulthood.

Complications of Osgood-Schlatter disease include persistent prominence  of the tibial tubercle, persistent pain and rarely genu recurvatum (hyperextension of the knee).

References

Mann DC et al. Distribution of physeal and nonphyseal fractures in 2,650 long bone fractures in children aged 0-16 years. Journal of Paediatric Orthopaedics (1990); 10:713.

Chapman J, Cohen J. Proximal tibial fractures in children. uptodate.com/contents/proximal-tibial-fractures-in-children

Little RM, Milewski MD. Physeal fractures about the knee. Current Reviews in Musculoskeletal Medicine. (2016); 9(4): 478–486

Coyle C et al. Tibial eminence fractures in the paediatric population: A systematic review. Journal of Children’s Orthopaedics. (2014); 8(2): 149–159

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Frey S et al. Tibial Tuberosity Fractures in Adolescents. Journal of Children’s Orthopaedics. (2008) 2:469–474

Watson-Jones R.  Fractures and joint injuries. Baltimore: Williams & Wilkins; 1955

Ogden JA, Tross RB, Murphy MJ. Fractures of the tibial tuberosity in adolescents. Journal of Bone and Joint Surgery Am. 1980;62(2):205–215

Pesl T; Havranek P. Acute tibial tubercle avulsion fractures in children: selective use of the closed reduction and internal fixation method. Journal of Children’s Orthopaedics. (2008) 2(5):353-6

Pretell –Mazzini J et al. Outcomes and Complications of Tibial Tubercle Fractures in Pediatric Patients: A Systematic Review of the Literature.  Journal of Paediatric Orthopaedics. (2016) 36(5): 440-46

De Lucena,G., Dos Santos Gomes,C. and Guerra,R.(2011) Prevalence and associated factors of Osgood-Schlatter syndrome in a population-based sample of Brazilian adolescents.American Journal of Sports Medicine. 2011; 39(2), 415-420

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Gholve PA, Scher DM, Khakharia S, et al. Osgood Schlatter syndrome. Current Opinion in Pediatrics. 2007;19:44-50.

Weiler R. Osgood-Schlatter Disease. BMJ, 2011;343:d4534

Atanda A., Shah S. and O’Brien K.Osteochondrosis: common causes of pain in growing bones.American Family Physician. 2011; 83(1), 285-291.

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