الفهرس 
Normal Limb Anatomy in ChildhoodOnly 14 pages are availabe for public view
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Abstract
Tibia vara was described by Blount in 1937. The 6 radiographic stages classification proposed by Langenskiöld and Riska in 1964 represents the progression of the disease if left untreated.
The etiology of tibia vara remains unknown; however, it was proposed that growth arrest of the posteromedial aspect of the proximal tibial physis is due to increased compressive forces on the medial side with tensile forces applied on the lateral aspect.
Early aggressive treatment of tibia vara is recommended before development of complex deformities of the proximal tibia with depression of the tibial plateau. The earlier the management and stage of disease, the less likely the incidence of recurrence. The management of early stages consists mainly of a metaphyseal valgus osteotomy with a slight over-correction to alter the compressive forces on the medial physis to tensile forces.
However, advanced stages of the disease represent a more challenging case, due to high rates of recurrence and possibly the permanent damage to the medial physis. Left untreated, or treated by a simple metaphyseal osteotomy, the knee joint it more prone to degenerative changes and osteoarthritis.
The surgery should be tailored to each patient, based on thorough analysis of each component of the deformity, age, weight and whether unilateral or bilateral affection.
Several techniques have been proposed for the surgical management of severe cases of tibia vara. Such techniques include metaphyseal valgus osteotomy, hemiepiphysiodesis, physeal bar resection, asymmetrical physeal distraction,
A variety of corrective osteotomies have been advocated, including closing wedge, opening wedge, dome, serrated, and inclined osteotomies.
The oblique osteotomy described by Rab begins at a point distal to the tibial tubercle, proximal to the posterior tibial metaphysis, and just distal to the physis and is done through a cosmetic transverse incision.
Correction is obtained by rotating around the face of the oblique osteotomy and can be described best by considering the individual cuts in their anatomical planes. Correction of a purely rotational deformity requires an osteotomy in the transverse plane, whereas purely varus correction requires osteotomy in the frontal (coronal) plane. An oblique osteotomy, directed from anterior-distal to posterior-proximal, splits the difference between the transverse and frontal planes. Rotation with its two faces in contact corrects varus and internal rotation. Osteotomy cuts that are more vertical (frontal) correct more varus than internal rotation. More horizontal (transverse) cuts do the opposite.
Informal reports from surgeons following the initial publication mentioned that excessive procurvatum of the tibia (beyond that which is typical of Blount’s disease) was seen with larger angular corrections. It is the result of an osteotomy plane that is started too laterally.
Modification of Rab osteotomy for correction of patients with infantile tibia vara. 45° upward cut based on the distal tibia, not the proximal in the orientation of the plane of cut, correction of the deformity was achieved in all patients. Union with no excessive procurvatum, occurred in each patient. There was no deep infection, no transient or permanent nerve palsies or deep infection and no instances of compartment syndrome.
This is a prospective study on 19 patients (25 limbs) with adolescent tibia vara treated by modified oblique high tibial osteotomy and minmal fixation by screws and above knee cast.
The mean time of follow-up was 11.35 months with a mean operative time of 60 minutes. The mean union time was 10.2 weeks. The mean pre-operative femoral shaft tibial shaft angle was 20.04° of varus, the mean post-operative angle was 2.04° valgus. The mean pre-operative medial proximal tibial angle was 75.57°, the mean post-operative angle was 87.96°. The mean pre-operative medial axis deviation was 76.13 mm; the mean post-operative angle was 5.74 mm.
Modified oblique high tibial osteotomy and screw fixation is a safe technique for correction of deformity of severe cases of tibia vara. Yet we need to wait for longer follow-up to assess its long term efficacy, and the confirmation of delayed or absent degenerative changes in adult life.