Feasibility study of correcting distal femoral valgus deformity with fixator-assisted plating technique in adolescent / 中华骨科杂志

ABSTRACT

Objective:Comparing with the external fixator technique, investigate the clinical effect of fixator-assisted plating technique for treatment distal femoral valgus deformity in adolescent.Methods:A retrospective analysis of the relevant data of 22 patients (25 limbs) with acute correction of distal femoral valgus deformities from July 2015 to June 2019, according to the difference of the final fixation, they were divided two groups. The fixator-assisted plating group, including 8 patients (9 limbs), 5 boys and 3 girls, 5 left and 2 right, 1 bilateral, the physis were closed in 4 cases and opened in 4 cases, age 14.04±1.99 years (11.7-18 years). The external fixator group, including 14 patients (16 limbs), 6 boys and 8 girls, 8 left and 4 right, 2 bilateral, the physis were closed in 9 cases and opened in 5 cases, age 13.33±1.88 years (10.1-16.5 years). Measuring the mechanical axis deviation (MAD) and the mechanical lateral distal femur angle (mLDFA) in full length standing AP view X-ray of the lower limb pre and post operation. Recording the changed of limb length discrepancy (LLD) before and after surgery and the knee range of motion at 6 weeks, 3 months, 6 months and the last follow up post operation. The Kolcaba comfort status scale was used to evaluate the comfort of two groups at 2 weeks, 6 weeks, 3 months, 6 months and the last follow up. Meanwhile recorded the healing time of osteotomy sites and the complications.Results:The difference in general information between the two groups was not statistically significant. The fixator-assisted plating group followed up mean 26 months (range, 12-40 months), the healing time were 4.00±0.66 months, the mLDFA mean 73.33°±4.12° before surgery and 87.89°±1.69° after surgery and there was significant difference ( t=10.582, P<0.05). The external fixator group followed up mean 36 months (range, 22-42 months), the healing time were 4.00±0.66 months, the mLDFA mean 73.31°±3.95° before surgery and 87.31°±1.54° after surgery and there was significant difference ( t=14.118, P<0.05). The MAD were in the normal range in all patients after surgery, and there were no significant difference about healing time of the osteotomy sites and postoperative mLDFA between the two groups ( t=1.514, P=0.150; t=0.845, P=0.411). Comparing with the knee function, the fixator-assisted plating group was better at 6 weeks, 3 months, 6 months after surgery but there was no difference at the last follow up. Also, the fixator-assisted plating group felt more comfortable at 2 weeks, 6 weeks, 3 months, 6 months and there was no difference at the last follow up. All the patients with external fixator have mild pin sites infection and there were no obvious complications in patients with plate. Conclusion:The fixator-assisted plating technique can accurately correct the valgus deformity with satisfactory healing of the osteotomy in distal femoral compare with the external fixator technique, but the patients feel more comfortable and the knee joint function recovers faster and no risk of pin site infection, the clinical results was satisfactory with fewer complication.