Low profile ilizarov frame in correction of varus deformity in patients with adolescent blount's disease

Background: Adolescent Blount disease or late onset tibia vara constitutes the most common cause of pathologic genu varum in late childhood and adolescence. It is a developmental condition characterized by disordered endochondral ossification of the posteromedial part of the proximal tibial physis resulting in multiplanar deformities of the lower limb

Objective: the aim of this work was to evaluate the results of treatment of acute correction of varus deformity in patients with Blount disease by using low profile Ilizarov frame

Patients and Methods: It is a retrospective and a prospective study for 10 patients who had adolescent Blount disease treated by acute correction using low profile Ilizarov frame. We looked principally into the following variables to evaluate the results of the treatment: Deformity correction [expressed as mechanical axis restoration], the average normal values were used as a reference [medial proximal tibial angle, 85-90; posterior proximal tibial angle, 77-84; thigh-foot angle, +10 external rotation]

Results: the patients were 9 boys [90%] and one girl [10%]. The mean age at presentation was 13.60 years, range [ 11- 17 years] , 6 patients [60%] presented with unilateral affections and 4 patients [40%] presented with bilateral affection. Mean preoperative to postoperative changes of MPTA from 74.57 [range 65-80] improved to 89.21 [range 86-95], Mean preoperative to postoperative changes of PPTA from 74.21 [range 66-80] improved to 79.07 [range 77-82] , Mean preoperative to postoperative changes of MAD from 31.14 mm [range 18-45 mm] improved to 3.64 mm [range 0-8 mm]. Mean preoperative to postoperative changes of TFA from -23.57 [range -30 -15] of internal tibial torsion improved to 5.36 [range 0-10] of external tibial torsion

Conclusion: Management of adolescent Blount disease by acute correction strategy using a low profile Ilizarov is a safe technique offering excellent results with low incidence of complications. Low profile Ilizarov is lighter and less bulky so more comfortable for patients than classic Ilizarov external fixation , Acute correction technique can achieve the same result of correction as gradual correction technique in patient with no limb length discrepancy , Acute correction offers a shorter time in frame as compared to gradual correction with fewer follow-up visits and exposure to radiation

Limb Angular Deformity Correction Using Dyna-ATC: Surgical Technique, Calculation Method, and Clinical Outcome

PURPOSE: Dyna-ATC is a unilateral external fixator with angulator, lengthener, and translator, which allows for angular correction and compensation of the secondary displacement during angular correction. The purpose of this study is to introduce surgical technique and calculation methods and to evaluate the clinical outcome of angular deformity correction using Dyna-ATC. MATERIALS AND METHODS: The amounts of secondary displacement were calculated with the distances between axis of correction of angulation, Center of Rotational Angulation, and osteotomy and the amount of angular deformity. The rate of angular correction was determined to distract the corticotomy at 1 mm/day. Clinical and radiographic evaluation was performed on 13 patients who underwent deformity correction using Dyna-ATC. There were 8 proximal tibia vara, 1 tibia valga, 2 varus and 4 valgus deformities on distal femur. One patient underwent pelvic support femoral reconstruction. Concomitant lengthening was combined in all femur cases. Mean age at surgery was 17.5 years (7 to 64). RESULTS: All but one achieved bony healing and normal alignment with the index procedure. Mean mechanical axis deviation improved from 31.9 mm to 3.0 mm. The average amount of angular correction was 11.0degrees on tibiae and 10.0degrees on femora. The average length gain on femora was 6.4 cm, and the healing index averaged to 1.1 mo/cm. One patient underwent quadricepsplasty and one patient had three augmentation surgeries due to poor new bone formation. CONCLUSION: We believe that Dyna-ATC is a useful alternative to bulky ring fixators for selective patients with angular deformity less than 30 degrees in the coronal plane around the knee joint.