الفهرس 
AIM OF THE WORKOnly 14 pages are availabe for public view
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Abstract
Tibia vara (Blount’s disease) is one of the pathological causes of genu varum. It can be classified into infantile and late-onset (juvenile and adolescent) types. Both have similar aetiology, and histopathology, but different radiographic findings.
The cause of Blount disease remains controversial, Biomechanical overload of the proximal tibial physis due to static varus alignment and excessive body weight have been implicated in the etiology of infantile tibia vara. Genetic factors may have a role in the development of tibia vara. Patients are obese with progressive deformity without apparent cause. The deformity elements usually are varus, internal torsion and sometimes procurvatum of the tibia. Associated femoral deformity may be present.
Full length radiological picture is very important to assess the malaginment of limb and detect the bone which deformed, what part is affected and the degree of deformity. The mechanical axis of the limb is the most valuable measurement. A detailed preoperative plan is essential for any surgical procedure. The overall plan should target each of the constituent deformities. Intraoperative radiographs are necessary to check the final alignment.
For children aged 3 years or less with Langenskiöld I, or II, brace treatment is recommended for an average of one year. Surgical treatment is indicated for infantile tibia vara at age 4 years or less with failure of orthotic management, or Langenskiöld grade III or greater. Proximal tibial valgus osteotomy with fibular diaphyseal osteotomy with or without limited internal fixation is usually the procedure of choice. For patients in Langenskiöld stage IV to VI, the deformity cannot be definitively corrected by simple mechanical alignment because physeal arrest has already occurred.
Corrective osteotomy for tibia vara may be performed with acute or gradual correction. The characteristics of the patient and the deformity dictate the method and type of fixator to be used the degree of deformity, patient related factors; like social and psychological factors, the age and weight of the patient and surgeon related factors like preference and experience may play certain role in determining the option of treatment. The maximum limits for acute correction of deformities have not, however, been clearly defined, the surgeons usually rely on experience to decide how much of deformity can be corrected acutely, but many series reported a range of maximal deformity angle that can be corrected acutely between 20 -40 degree.
Many types of osteotomies have been described, including focal dome, straight cut, Rab, opening wedge, closing wedge, and spike, inverted U, inverted V, percutaneous afghan, W/M, chvron and triple osteotomy. Fixation devices such as casting, K-wires, pins, plates and screws, and external fixation have been reported. Prospective randomized controlled trial is the best method to determine which modality of deformity correction is the best.
Wire and pin problems are among the most common complications, however, they can be diminished with meticulous pin care. This requires a high degree of patient and parent cooperation. Other complications include neurologic and vascular injuries, contractures, angular deformities, fracture after frame removal, joint subluxation, joint stiffness, premature consolidation, delayed consolidation and conditions such as deep vein thrombosis and pulmonary embolism. Direct injury occurs during wire or pin insertion. Acute deformity correction is associated with an increased risk of neurovascular insult and compartment syndrome, particularly with large deformities. Stress risers are created at pin sites after removal, and fractures through these sites are possible.
Finally, regardless the treatment method used, in order to obtain good satisfactory results; the most important point is careful preoperative planning and intraoperative and postoperative assessment with enough attention given to the details of the selected technique.
Although the clinical presentations of Blount’s disease are commonly-known, this pathology remains a concern for healthcare professionals as it affects a vital portion of a child’s joint: the epiphyseal growth plate. Through displacement or damage of the proximal tibial epiphysis, a progressive outward bowing of the lower limb occurs. Furthermore, the formerly unreported symptom of Blount’s disease, slippage of the tibial epiphysis without a change in size or shape of the growth plate, reaffirms the importance of understanding the signs and indications of this disease process. With careful consideration for each patient’s unique circumstance, treatment through corrective bracing, growth plate manipulation, or tibial osteotomy can effectively repair the deformity. Left untreated, abnormal tibia vara can eventually lead to multi-planar deformity and degenerative arthritis later in life, so it is essential that all modalities are employed and all efforts are made to recognize and educate about this disease.