Blount's Disease Unit 6[1]

Blount’s Disease : 

Blount’s Disease Unit 6 Assignment October 11, 2011 Kathryn Bonvillian Jillianne Hart

Blount’s Disease: 

Blount’s Disease Description : Also known as Tibia Vara- it is the abnormal bone growth of the tibia at the epiphysis that results in a bowing of the lower extremities. Caused by abnormal weight distribution on the tibia Usually a result of obesity or early walking in infants Usually asymmetric or unilateral 1 , but can occur bilaterally 4 Incidence : Idiopathic cause May have a genetic link, although a particular gene has not been identified 4 Young children and adolescents More common in females More common in African Americans More common in Africa, the West Indies, and Finland 4

Main Types: 

Main Types Infantile - most common, early onset- 1-3 years, progressive deformity Juvenile - later onset >4 years, usually an infantile case that was not treated earlier, less common

Signs and Symptoms: 

Signs and Symptoms Signs May have abnormal gait Bowing at the knees Rotational deformity called in-toeing 4, where lower extremities start to turn in. This disease has rapid progression. Symptoms 4 Generally, children have few significant symptoms and do not experience pain from their condition. Occasionally, children may experience some discomfort in the legs near the knees May have some instability when walking

Diagnosis and Prognosis: 

Diagnosis and Prognosis Diagnosis 6 Stage Classification system 1 Physical examination Imaging by a medical doctor: Best: Anterioposterior radiograph of bilateral lower extremitites Secondary: an MRI Prognosis Good prognosis, if treated early 1,4 If not surgically corrected, could result in 5,6,7 : Vascular problems Malalignment Fractures wound infection Progressive deformities

Impairments and Functioning: 

Impairments and Functioning Impairments : Abnormal gait Leg length discrepancy Muscle imbalances caused by abnormal alignment 1,7 Decreased muscle strength 7 Impact on Functioning : Poor gait Children may experience some discomfort in the legs near the knees 4 May have some instability when walking 4

Treatment4: 

Treatment 4 Observation Mild bowing Children under 2 years old Progression monitored by an orthopedic surgeon In many cases, it will correct itself over the course of about 1 year without any further treatment by a doctor Orthotics Bowing worsens Children 2 to 4 years old Usually fitted with knee ankle foot orthotic (KAFO) Goal is to gradually guide the growth of the legs towards a straighter position of the legs, so that the knees and feet are aligned properly Monitored by an orthopedic surgeon through the use of radiographs and physical examinations Weight management would be beneficial, if it was seen as a possible cause.

Surgical Treatment4: 

Surgical Treatment 4 Severe bowing Children 3 to 4 years old Ineffective bracing Osteotomy A very small wedge of the tibia (shinbone), and sometimes the fibula, is removed in an effort to realign the lower leg in a straighter position. Small pins are inserted in order to maintain this realignmen A cast extending from above the knee to the foot is applied. About 1 month following the operation, the pins are removed and a new cast is applied, which is generally worn for another 2 to 3 months. Epiphysiodesis The epiphysis is removed in order to halt the abnormal growth of the tibia and correct its alignment External fixation Following an osteotomy , in which a device on the outside of the leg is attached to the leg for a number of months with small metal bars, which facilitates the proper healing of the newly aligned tibia.

Physical Therapy Treatment: 

Physical Therapy Treatment Physical therapist will be helpful in early conservative treatments to give exercises and techniques to promote function. Activity modification in order to minimize the unnatural stresses on the lower extremity during weight-bearing. Role in rehabilitation after surgery to help return the patient to function with strengthening and gait training. Ensure that the surrounding soft tissues remain flexible as the bone heals, and that muscle strength is maintained 8 Attached please find two YouTube video of a little boy named Ben who has Blount’s disease. He is seen ambulating with orthotics. Ben Has Blount’s Ben Has Blount’s

Role of Imaging: 

Role of Imaging Radiograph Best source for diagnosis, progression, and healing Best view: Anterioposterior radiograph of bilateral lower extremitites 1 Show the abnormal shape of the tibia 4 Possibly shows the changes in the epiphysis of the bone just under the knee 4 Allows orthopedic surgeons to measure the angles of the different segments of the leg 1,4 MRI 1 View and evaluate the growth plate Can assist in surgical planning Predict development of Blount disease in patients with severe physiologic bowing

Radiograph: 

Radiograph

Radiographic Findings:: 

Radiographic Findings: Alignment General Skeletal Architecture : Developmental deformity of the tibia, often termed tibia vara .  There is a disturbance of growth of the medial proximal tibial epiphysis. General Contour of Bone :  The tibia becomes “bow” shaped.  There is space within the epiphyseal line, not fused when compared to other lines present in radiograph. Alignment of bones :  The tibia is laterally shifted relative to the femur.  Fibula is posterior to the tibia, hence the superimposition. Bone Density General Bone Density :  Normal between cortical and cancellous bone. Textural Abnormalities : There seems to be bony growth occuring at the epiphyseal plates, but inconsistent fusion is occurring. Local Density Changes :  There is an increase in the width of cortical bone on the medial and lateral sides of the tibial shaft on the left lower extremity.

Radiographic Findings continued:: 

Radiographic Findings continued: Cartilage : Joint Space Width : Medial tibiofemoral joint space is increased due to depression of the medial condyle / epicondyle . Subchondral bone : N/A Epiphyseal Plates : Course margins.  Increased space within the line.  Inconsistent fusion within the epiphyseal plates. Sclerosing in small areas indicating bone growth activity. Soft Tissues : Muscle s: Due to the malalignment of the tibia, the musculature appears to be in an improper position Fat Pads/lines : N/A Joint Capsules : Normal Periosteum : N/A Miscellaneous : The patient appears to be obese which is a common factor in patients with a presentation of Blount’s disease

Radiograph Predictor Variables4: 

Radiograph Predictor Variables 4 Behavior of lesion :  Tibia Vara formation secondary to early walking or obesity in the pediatric population. Osteoblastic activity still occurring in the metaphysis and epiphysis. Bone or Joint involved :  Tibia Locus in bone : The metaphyseal and epiphyseal region of the tibia Age, Gender, Race : Young children and adolescents. More common in females and African Americans. Margin of Lesion : Wide poorly defined margins of the epiphyseal line and tibial plateau Shape of lesion : Tibia becomes in a varus position with an unfused epiphyseal line and depressed medial epicondyle Joint space crossed : The shape of the tibia displaces the normal alignment of the tibiofibular joint.  The joint becomes more posterior. Bony reaction : N/A Matrix production : N/A Soft Tissue changes : The radiograph may display obesity in the patient or hypertrophied muscular in the limbs secondary to compensations of the deformation. History of trauma or Surgery : Trauma N/A. Surgery may be indicated for medical treatment of this disease.

Possible impairments based on these radiographic findings…: 

Possible impairments based on these radiographic findings… Biomechanical: Abnormal anterior and posterior glides of the knee Abnormal arthrokinematics up and down the kinetic chain (hip and foot/ankle) as a compensation Abnormal articulation of the tibiofemoral and tibiofibular joints Physical: Abnormal gait Abnormal ligamentous pull Abnormal muscle pull Decreased muscle strength Possible leg length discrepancy

MRI: 

MRI

MRI Findings1 : 

MRI Findings 1 Metaphyseal changes in both the proximal tibia and the distal femur Physeal widening is noted in the proximal tibia medially (arrow). T1-weighted MR images show abnormal metaphyseal signal intensity in the distal femur and proximal tibia (arrowheads).

Possible impairments based on these MRI findings…: 

Possible impairments based on these MRI findings… Biomechanical : Abnormal arthrokinematics between the femur and tibia Abnormal arthrokinematics up and down the kinetic chain (hip and foot/ankle), as a compensation Physical : Abnormal gait Abnormal ligamentous pull Abnormal muscle pull Decreased muscle strength Possible leg length discrepancy

Questions: 

Questions What measurement is used to distinguish Blount’s disease from developmental bowing (please explain the process)? What range of degrees is indicative of Blount’s disease?

References: 

References Cheema J, Chrissom L, Harcke T. Radiographic Characteristics of Lower extremity Bowing in Children. Radiographics . 2003;23, 871-880 Blount’s Disease. Pubmed Health. National Center for Biotechnology Information, U.S. National Library of Medicine. 2011. A.D.A.M., Inc . Available at: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002551/ VCU Health System Pediatric Radiology. Blount’s Disease. Available at http://www.pedsradiology.com/Historyanswer.aspx?qid=38&fid=1 Blount’s Disease.  Columbia Orthopaedics .  Available at: http://childrensorthopaedics.com/blountsdisease.html .  Accessed October 4, 2011. DeOrio , M.J. Blount Disease Treatment & Management. http://emedicine.medscape.com/article/1250420-treatment#a17 . Updated September 25, 2010. Accessed October 5, 2011. Kaneshiro , Neil. Blount's Disease. Health Guide.  Available at:  http://health.nytimes.com/health/guides/disease/blounts-disease/overview.html.  Accessed October 5, 2011. Wills, Mary. Orthopedic Complications of Childhood Obesity. Pediatric Physical Therapy.  Available at:  http://www.integrehab.com/library/Childhood_Obesity_and_Orthop_Complications.pdf.  Accessed October 5, 2011. Blanco JS and Widmann RF. Limb (Leg) Deformity Reconstruction for the Pediatric Patient. Available at: http://www.hss.edu/conditions_limb-leg-deformity-pediatric-patient.asp . Accessed October 11, 2011.