To evaluate the operative treatment of Blount disease using the TSF external fixator and to evaluate the system.

During January 2004 and August 2008, 8 males and 2 females with Blount disease (16 limbs) were treated using TSF system. For the radiological assessment we obtained standard long-leg standing radiographs and we measured the anatomic medial proximal tibial angle (aMPTA), the diaphyseal-metaphyseal tibial angle (Drennan), and the femoro-tibial angle.

The mean follow-up was 29 months (15 to 45). No patient had pain around the knee, medial or lateral instability. The range motion of the knee immediately after frame removal was 10° to 90° of flexion in two patients while in the other it was from 0° to 110°. The mean leg-length discrepancy was reduced postoperatively from mean 1,9 cm (1,7–3,2) to 0,9 cm (0− +1,5). The aMPTA angle increased from mean 73° (59°– 83°) to 94° (107°–90°), Drennan angle from 17° (14°–22°) to 3° (0°–7°), and femoro-tibial angle from 17° (10°–30°) varus to 7° (2°–10°) valgus. The frame was removed at mean 9 weeks (7–14). Two patients had delayed union, two presented with loss of correction (due to dissociation of struts and secondary to medial physeal bar), two patients had pin track infection. No neurologic complications were referred.

Accurate corrections of multiplanar deformities as varus, internal rotation and shortening of the limb that coexist in Blount disease may be accomplished using TSF system

To study the use of TSF system in treating trauma and bone deformities in children. To determine the difficulties of this process and the risk factors that lead to complications.

From January 2004, in 61 children (37 male and 24 female), 67 extremities, with a mean age 8.9 years children a TSF external fixator was applied for the treatment of trauma or bone deformities. 21 children were operated for angular deformity, 19 for bone lengthening, 10 for rotational deformity, 6 for combined angular deformity and lengthening and 11 for pseudoarthrosis. Intra and postoperative difficulties were classified using the Palay method in problems, obstacles and complications.

The rate of difficulties was 22.2 %. Problems were presented in 5.9% (4/67) consisting of 2 non-axial deformities, 1 pin fracture and 1 subluxation of the knee. Obstacles were presented in 10.4% (9/67) including 3 cases with delayed bone healing that needed infusion DBM, 1 peroneal nerve palsy due to hematoma formation treated with decompression of the region, 1 early bone fusion that needed re-operation and 2 cases of percutaneous achilles lengthening. Complications presented in 5.9% of (4/67) the cases including 1 fracture, 1 pseudoarthrosis, 1 peroneal nerve palsy and 1 limitation of range of motion in the knee (0–45 0).

The problems, obstacles and complications that presented during treatment influenced the final therapeutic objective. Initial deformity, preoperative planning and surgeon’s experience are associated with reducing the rate of all difficulties