Blount's Disease: Difference between revisions
Leana Louw (talk | contribs) No edit summary |
Leana Louw (talk | contribs) No edit summary |
||
| Line 9: | Line 9: | ||
== Description == | == Description == | ||
Blount's disease, also known as tibia vara, is a developmental growth disorder of the [[tibia]] that causes the lower leg to angle outwards, causing bowing of the leg. It is characterised by progressive multiplanar deformities of the leg caused by disordered endochondral ossification of the proximal medial tibial physis. | Blount's disease, also known as infantile tibia vara, is a developmental growth disorder of the [[tibia]] that causes the lower leg to angle outwards, causing bowing of the leg. It is characterised by progressive multiplanar deformities of the leg caused by disordered endochondral ossification of the proximal medial tibial physis.<ref name=":0" /><ref name=":1">Medscape. Blount Disease Imaging. Available from: https://emedicine.medscape.com/article/406458-overview (accessed 25/05/2020).</ref> | ||
The cause of Blount's disease is assumed to be multifactoral, mostly mechanically due to childhood obesity.<ref name=":0">Sabharwal S. [https://s3.amazonaws.com/academia.edu.documents/41528057/Blount_CCR_JBJS.pdf?response-content-disposition=inline%3B%20filename%3DBlount_CCR_JBJS.pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIATUSBJ6BAI2IGOEXQ%2F20200501%2Fus-east-1%2Fs3%2Faws4_ Blount disease.] Journal of Bone and Joint Surgery 2009;91(7):1758-76.</ref> This can be described by the effects of increased weight on the growth plates. The medial proximal [[tibia]] fails to develop normally, resulting in genu varum.<ref>Erkus S, Turgut A, Kalenderer O. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6699207/ Langenskiöld classification for blount disease: Is it reliable?] Indian journal of orthopaedics 2019;53(5):662.</ref> Unlike bowlegs, which tend to straighten as the child develops, Blount's disease is progressively worsening. It can cause severe bowing and can affect one or both legs.<br> | The cause of Blount's disease is assumed to be multifactoral, mostly mechanically due to childhood obesity.<ref name=":0">Sabharwal S. [https://s3.amazonaws.com/academia.edu.documents/41528057/Blount_CCR_JBJS.pdf?response-content-disposition=inline%3B%20filename%3DBlount_CCR_JBJS.pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIATUSBJ6BAI2IGOEXQ%2F20200501%2Fus-east-1%2Fs3%2Faws4_ Blount disease.] Journal of Bone and Joint Surgery 2009;91(7):1758-76.</ref> This can be described by the effects of increased weight on the growth plates. The medial proximal [[tibia]] fails to develop normally, resulting in genu varum.<ref>Erkus S, Turgut A, Kalenderer O. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6699207/ Langenskiöld classification for blount disease: Is it reliable?] Indian journal of orthopaedics 2019;53(5):662.</ref> Unlike bowlegs, which tend to straighten as the child develops, Blount's disease is progressively worsening. It can cause severe bowing and can affect one or both legs.<br> | ||
| Line 30: | Line 30: | ||
== Classification == | == Classification == | ||
Blount's disease is mostly catagorised into early-onset if it develops in children under 4 years old, and late-onset, when it develops after the age of 4.<ref name=":0" /> The late-onset type can further be classified into juvenile (age 4 - 10) and adolescent (after the age of 10) Blount's disease.<ref>Thompson GH, Carter JR. [https://europepmc.org/article/med/2189629 Late-onset tibia vara (Blount's disease). Current concepts.] Clinical orthopaedics and related research 1990(255):24-35.</ref> | Blount's disease is mostly catagorised into early-onset if it develops in children under 4 years old, and late-onset, when it develops after the age of 4.<ref name=":0" /> The late-onset type can further be classified into juvenile (age 4 - 10) and adolescent (after the age of 10) Blount's disease.<ref>Thompson GH, Carter JR. [https://europepmc.org/article/med/2189629 Late-onset tibia vara (Blount's disease). Current concepts.] Clinical orthopaedics and related research 1990(255):24-35.</ref> <br> | ||
== Clinical Presentation == | == Clinical Presentation == | ||
* Unilateral or bilateral (mostly with early onset) presentation | * Unilateral or bilateral (mostly with early onset) presentation:<ref name=":1" /> | ||
** 80% of early-onset and 50% of late-onset cases are bilateral | |||
* Multiplanar progressive deformities of the lower leg includes:<ref name=":0" /> | * Multiplanar progressive deformities of the lower leg includes:<ref name=":0" /> | ||
** [[Tibia|Tibial]] varus | ** [[Tibia|Tibial]] varus | ||
| Line 48: | Line 47: | ||
* Early onset [[Knee Osteoarthritis|knee osteoarthritis]] as result of deformities | * Early onset [[Knee Osteoarthritis|knee osteoarthritis]] as result of deformities | ||
== Diagnostic Procedures == | == Diagnostic Procedures == | ||
Diagnosis are normally made by a clinical assessment and the use of [[X-Rays|X-rays]] (full length, AP and lateral). [[X-Rays|X-rays]] are use to determine and measure the extent of the deformities. In late-onset Blount's disease, advanced imaging are not routinely done. Other additional investigations include:<ref name=":0" /> | Diagnosis are normally made by a clinical assessment and the use of [[X-Rays|X-rays]] (full length, AP and lateral). [[X-Rays|X-rays]] are use to determine and measure the extent of the deformities. In late-onset Blount's disease, advanced imaging are not routinely done.<ref name=":0" /> The deformity of the proximal medial tibial metaphysis is palpatable as a non-tender bony protuberance.<ref name=":1" /> | ||
protuberance can be palpated along the medial aspect of the proximal tibia, representing the deformed medial tibial metaphysis. | |||
Other additional investigations include:<ref name=":0" /> | |||
* Scanogram: To determine leg length discrepancy | * Scanogram: To determine leg length discrepancy | ||
* Arthrogram (intra-operative): Assessment of articular surface postion | * Arthrogram (intra-operative): Assessment of articular surface postion | ||
| Line 104: | Line 107: | ||
** Aim to achieve multiplanar correction | ** Aim to achieve multiplanar correction | ||
* The growth of just the outer half of the tibia can be surgically restricted to allow the child’s natural growth to reverse the bowing process. This much smaller surgery is most effective in children with less severe bowing and significant growth remaining.<ref name=":0" /> | * The growth of just the outer half of the tibia can be surgically restricted to allow the child’s natural growth to reverse the bowing process. This much smaller surgery is most effective in children with less severe bowing and significant growth remaining.<ref name=":0" /> | ||
== Differential Diagnosis == | == Differential Diagnosis == | ||
* Physiologic bowing | |||
* Congenital bowing | |||
* Rickets | |||
* Ollier disease | |||
* Trauma-related deformities | |||
* [[Osteomyelitis]] | |||
* Metaphyseal chondrodysplasia | |||
== Resources == | == Resources == | ||
{{#ev:youtube|watch?v=aEqIp1aop8c}} | {{#ev:youtube|watch?v=aEqIp1aop8c}} | ||
== References == | == References == | ||
Revision as of 17:02, 25 May 2020
This article is currently under review and may not be up to date. Please come back soon to see the finished work! (25/05/2020)
Original Editors - Rachael Lowe
Top Contributors - Leana Louw, Admin, Kim Jackson, Daphne Jackson, Evan Thomas and WikiSysop
Description[edit | edit source]
Blount's disease, also known as infantile tibia vara, is a developmental growth disorder of the tibia that causes the lower leg to angle outwards, causing bowing of the leg. It is characterised by progressive multiplanar deformities of the leg caused by disordered endochondral ossification of the proximal medial tibial physis.[1][2]
The cause of Blount's disease is assumed to be multifactoral, mostly mechanically due to childhood obesity.[1] This can be described by the effects of increased weight on the growth plates. The medial proximal tibia fails to develop normally, resulting in genu varum.[3] Unlike bowlegs, which tend to straighten as the child develops, Blount's disease is progressively worsening. It can cause severe bowing and can affect one or both legs.
Pathogenesis[edit | edit source]
Looking at the Heuter-Volkmann principle, the pathogenesis of Blount's disease can be described as growth inhibition caused by excessive compressive forces. This pressure on the medial proximal tibia causes structure and function alterations on the cartilage of the epiphysis, further causing chondrocytes and delaying in epiphysis ossification. The increase in medial load with obesity usually lead to genu varum.
Etiology / Epidemiology[edit | edit source]
The following are known predisposing factors of Blount's disease:[1]
- This condition is more common among children of African and Scandanavian ancestry.
- It is associated with obesity, short stature, and early walking.
- There does not appear to be an obvious genetic factor.
genetic, humoral, biomechanical, and environmental factors control physeal growth and influence the development of normal lower-limb alignment. control physeal growth and influence the development of normal lower-limb alignment. T
Classification[edit | edit source]
Blount's disease is mostly catagorised into early-onset if it develops in children under 4 years old, and late-onset, when it develops after the age of 4.[1] The late-onset type can further be classified into juvenile (age 4 - 10) and adolescent (after the age of 10) Blount's disease.[4]
Clinical Presentation[edit | edit source]
- Unilateral or bilateral (mostly with early onset) presentation:[2]
- 80% of early-onset and 50% of late-onset cases are bilateral
- Multiplanar progressive deformities of the lower leg includes:[1]
- Tibial varus
- Procurvatum
- Internal torsion
- Limb shortening (due to altered growth)
- Distal femoral varus (in late-onset)
- Gait abnormalities:
- Early onset knee osteoarthritis as result of deformities
Diagnostic Procedures[edit | edit source]
Diagnosis are normally made by a clinical assessment and the use of X-rays (full length, AP and lateral). X-rays are use to determine and measure the extent of the deformities. In late-onset Blount's disease, advanced imaging are not routinely done.[1] The deformity of the proximal medial tibial metaphysis is palpatable as a non-tender bony protuberance.[2]
protuberance can be palpated along the medial aspect of the proximal tibia, representing the deformed medial tibial metaphysis.
Other additional investigations include:[1]
- Scanogram: To determine leg length discrepancy
- Arthrogram (intra-operative): Assessment of articular surface postion
- CT scan: 3D surgical planning (early-onset disease with recurrent deformities)
- MRI: Determine
- Determine intra-articular changes to tibial plateau (e.g. posteromedial depression)
- Look for medial meniscus hypertrophy in early-onset disease
- Assess physeal bar formation and changes to growth plates
Langenskiöld classification[edit | edit source]
This classification system are used to describe the radiographic changes and are divided into 6 progressive type in early onset Blount's disease, describing changes with aging.[1][5]
- Stage 1: Age 2-3
- Metaphyseal irregularities in ossification zone
- Slow development of epiphysis in medial aspect of tibia
- Medial and/or distal beaking of medial epiphysis
- Stage 2: Age 2.5-4
- Medial physeal line depresses sharply
- Beaking medially
- Wegde-shaping and underdevelopment of medial epiphysis
- Stage 3: Age 4-6
- Metaphyseal beak depression deepens
- Metaphysis "step"
- Medial part of epiphysis more wedge-shaped and underdeveloped
- Stage 4: Age 5-10
- Narrowing of physis
- Enlargement of epiphysis
- Metaphysis "step" deepens
- Depression in medial metaphysis ocupied by epiphysis
- Stage 5: Age 9-11
- Clearly separated epiphysis in two parts
- Epiphysial plate partially double
- Articular surface medially sloping
- Stage 6: Age 10-13
- Ossification of medial physis with cessation of growth
- Normal lateral tibial growth
Outcome Measures[edit | edit source]
add links to outcome measures here (see Outcome Measures Database)
Medical management[edit | edit source]
Conservative management[edit | edit source]
Children who develop severe bowing before the age of 3 may be treated with bracing. However, bracing may fail, or bowing may not be detected until the child is older.
Surgical management[edit | edit source]
- Realignment tibial osteotomy: To be done before the age of 4 to decrease the risk of recurrent lower extremity deformity and to restore leg length where needed.[1]
- Distraction osteogenesis: For late-onset disease:[1]
- Aim to achieve multiplanar correction
- The growth of just the outer half of the tibia can be surgically restricted to allow the child’s natural growth to reverse the bowing process. This much smaller surgery is most effective in children with less severe bowing and significant growth remaining.[1]
Differential Diagnosis[edit | edit source]
- Physiologic bowing
- Congenital bowing
- Rickets
- Ollier disease
- Trauma-related deformities
- Osteomyelitis
- Metaphyseal chondrodysplasia
Resources[edit | edit source]
References[edit | edit source]
References will automatically be added here, see adding references tutorial.
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Sabharwal S. Blount disease. Journal of Bone and Joint Surgery 2009;91(7):1758-76.
- ↑ 2.0 2.1 2.2 Medscape. Blount Disease Imaging. Available from: https://emedicine.medscape.com/article/406458-overview (accessed 25/05/2020).
- ↑ Erkus S, Turgut A, Kalenderer O. Langenskiöld classification for blount disease: Is it reliable? Indian journal of orthopaedics 2019;53(5):662.
- ↑ Thompson GH, Carter JR. Late-onset tibia vara (Blount's disease). Current concepts. Clinical orthopaedics and related research 1990(255):24-35.
- ↑ Radiopedia. Langenskiold classification of Blount disease. Available from: https://radiopaedia.org/articles/langenskiold-classification-of-blount-disease (accessed 06/05/2020).
