Risk factors of transport gap bending deformity in the treatment of critical-size bone defect after bone transport

Abstract

Background The purpose of this study was to investigate the risk factors of transport gap bending deformity (TGBD) in the treatment of critical-size bone defect (CSBD) after the removal of the external fixator. Methods From January 2008 to December 2019, 178 patients with bone defects of the lower extremity caused by infection were treated by bone transport using a unilateral external fixator in our medical institution. TGBD was defined as the bone callus in the distraction area with a deviation to the force line of the femur (> 10°) or tibia (> 12°) after removal of the external fixator. The Association for the Study and Application of the Method of Ilizarov (ASAMI) standard was applied to assess the bone and functional outcomes. After the data were significant by the T-test or Pearson’s Chi-square test was analyzed, odds ratios were calculated using logistic regression tests to describe factors associated with the diagnosis of TGBD. Results A total of 178 patients were enrolled in the study, with a mean follow-up time of 28.6 ± 3.82 months. The positive result of the bacteria isolated test was observed in 144 cases (80.9%). The rate of excellent and good in the bone outcomes (excellent/good/fair/poor/failure, 41/108/15/14/0) was 83.7%, and 92.3% in the functional results (excellent/good/fair/poor/failure, 50/98/16/14/0) according to the ASAMI criteria. TGBD after removal of external fixator occurred in twenty-two patients (12.3%), including 6 tibias, and 16 femurs. Age > 45 years, BMI > 25 kg/m2, femoral defect, diabetes, osteoporosis, glucocorticoid intake, duration of infection > 24 months, EFT > 9 months, EFI > 1.8 month/cm were associated significantly with a higher incidence of TGBD in the binary logistic regression analysis (P < 0.05). The incidence more than 50% was found in patients with femoral defect (76.1%), osteoporosis (72.7%), BMI > 25 kg/m2 (69.0%), diabetes (59.5%), glucocorticoid intake (54.7%). In the multivariate logistic regression analyses, the following factors were associated independently with TGBD, including age > 45 years, BMI > 25 kg/m2, femoral defect, diabetes, and osteoporosis. Conclusions Bone transport using a unilateral external fixator was a safe and practical method in the treatment of CSBD caused by infection. The top five risk factors of TGBD included femoral defect, BMI > 25 kg/m2, duration of bone infection > 24 months, age > 45 years, and diabetes. Age > 45 years, BMI > 25 kg/m2, femoral defect, osteoporosis, and diabetes were the independent risk factors. The higher incidence of TGBD may be associated with more risk factors.

Nomogram construction and validation of axial deviation in patients with tibial defects treated with the Ilizarov bone transport technique

“…In our study, the univariate and multivariate logistic regression analysis showed that gender, height, defect site, and external fixation index (EFI) were important risk factors for axial deviation. Multiple studies have examined the association between gender, defect site, and EFI with axial deviation, reporting various findings [ 7 , 24 , 25 ]. Firstly, the gender factor potentially exerts a certain degree of influence on axial deviation during bone transport procedures.…”

Improvements in Pediatric Bone Loss Reconstruction With the Induced Membrane Technique

“…Before the advent of the induced membrane technique, bone reconstructions were centered around the use of a vascularized fibula graft [17][18][19][20][21] and bone transfer according to Ilizarov. [22][23][24] These surgeries are technically difficult, the results random [25][26][27] and less well tolerated in the pediatric population in relation with wearing an external fixator for a long period of time. 7,8 Although being one of the reference solutions, the original Masquelet's technique in young children is limited by the small volume of the iliac crests, constituting an insufficient supply of autologous cancellous bone graft to fill the important bone losses, resulting in a longer bone regeneration and fragility.…”