Comparison of fixator-assisted nailing versus circular external fixator for bone realignment of lower extremity angular deformities in rickets disease

In rickets patients, limb deformities are usually multiapical and complex even with medical treatment; residual deformities remain necessitating surgical correction. In our study we aim to compare the results of correction of lower limb deformities, in rickets patients, treated with circular external fixator versus fixator-assisted intra-medullary nail.

Seventeen rickets patients, with 39 deformed lower extremity segments (femur and or tibia), underwent deformity correction procedures in our institution. Ten patients with 26 segments were treated using fixator-assisted nailing. Nine patients with 17 segments were treated using Ilizarov technique with circular frame. All patients were evaluated by long-standing true anteroposterior and lateral orthoroentgenograms of lower extremities preoperatively. Joint alignment, joint orientation, and apices of deformities were calculated and noted. The postoperative results of MAD, MPTA, LDFA, PPPTA and functional criteria were compared with preoperative values and assessments made in SPSS 13.0 for Windows by using McNemar, Pearson Chisquare, and Fisher exact statistical tests.

Mean age for the fixator-assisted nailing (FAN) group patients at the time of surgery was 23.8 years (14–37 years). There were 16 femur and 10 tibiae operated on 6 female and 4 male patients. The mean follow up time is 42.6 months (6–71 months). In the Ilizarov group patients the mean age at the time of surgery was 16.7 years (13–22 years). There were 14 tibiae and 3 femur operated on 6 female and 3 male patients. The mean follow-up time was 19 months (6–48 months). Results were evaluated according to the Paley et al. classification of bone and functional results. According to those criteria we had 1 fair, 1 good, and 7 excellent bone results and 1 fair, 1 good, and 7 excellent functional results in the circular ring fixator group. In the FAN group we found 3 good and 7 excellent bone results; 1 fair, 2 good, and 7 excellent functional results. Nearly all patients complained of pain, limping, instability, and walking problems at their first preoperative visit. In both groups there was no union problem; in the FAN group, in one patient correction loss occurred and in another one screw loosening was encountered; in the Ilizarov group, 66% of patients had pin tract infections and one premature fibula consolidation occurred. Statistical analysis revealed no significant difference between two groups in correction ratios.(pearson chi square p = 0.332 for MAD; pearson chi square p = 0.477 for LDFA; Paley functional criteria fisher exact p = 0.684).

The results indicated that fixator-assisted nailing carries deformity correction accuracy comparable with Ilizarov-type external fixators. FAN provides great patient comfort and the total treatment time is less. In patients with rickets, the retained IM nail can further provide protection against recurrence even if the metabolic pathology reoccurs.