Ilizarov bone transport combined with the Masquelet technique for bone defects of various etiologies (preliminary results)

BACKGROUND

The Ilizarov bone transport (IBT) and the Masquelet induced membrane technique (IMT) have specific merits and shortcomings, but numerous studies have shown their efficacy in the management of extensive long-bone defects of various etiologies, including congenital deficiencies. Combining their strong benefits seems a promising strategy to enhance bone regeneration and reduce the risk of refractures in the management of post-traumatic and congenital defects and nonunion that failed to respond to other treatments.

AIM

To combine IBT and IMT for the management of severe tibial defects and pseudarthrosis, and present preliminary results of this technological solution.

METHODS

Seven adults with post-traumatic tibial defects (subgroup A) and nine children (subgroup B) with congenital pseudarthrosis of the tibia (CPT) were treated with the combination of IMT and IBT after the failure of previous treatments. The mean number of previous surgeries was 2.0 ± 0.2 in subgroup A and 3.3 ± 0.7 in subgroup B. Step 1 included Ilizarov frame placement and spacer introduction into the defect to generate the induced membrane which remained in the interfragmental gap after spacer removal. Step 2 was an osteotomy and bone transport of the fragment through the tunnel in the induced membrane, its compression and docking for consolidation without grafting. The outcomes were retrospectively studied after a mean follow-up of 20.8 ± 2.7 mo in subgroup A and 25.3 ± 2.3 mo in subgroup B.

RESULTS

The “true defect” after resection was 13.3 ± 1.7% in subgroup A and 31.0 ± 3.0% in subgroup B relative to the contralateral limb. Upon completion of treatment, defects were filled by 75.4 ± 10.6% and 34.6 ± 4.2%, respectively. Total duration of external fixation was 397 ± 9.2 and 270.1 ± 16.3 d, including spacer retention time of 42.4 ± 4.5 and 55.8 ± 6.6 d, in subgroups A and B, respectively. Bone infection was not observed. Postoperative complications were several cases of pin-tract infection and regenerate deformity in both subgroups. Ischemic regeneration was observed in two cases of subgroup B. Complications were corrected during the course of treatment. Bone union was achieved in all patients of subgroup A and in seven patients of subgroup B. One non-united CPT case was further treated with the Ilizarov compression method only and achieved union. After a follow-up period of two to three years, refractures occurred in four cases of united CPT.

CONCLUSION

The combination of IMT and IBT provides good outcomes in post-traumatic tibial defects after previous treatment failure but external fixation is longer due to spacer retention. Refractures may occur in severe CPT.

[Concentration of several osteotropic growth factors, markers of osteogenesis and biologically active molecules in the blood serum of patients with congenital pseudarthrosis of tibia during orthopaedic treatment with combined technologies]

Congenital pseudarthrosis of tibia is a genetic, systemic pathology with impaired bone remodeling and unknown pathogenetic mechanisms. Orthopaedic treatment of the disease can fail in some cases. The process of bone remodeling is known to occur under control of local and systemic growth factors, and we sought to explore several osteotropic growth factors, markers of osteogenesis and biologically active molecules in the blood serum of patients with congenital pseudarthrosis of tibia. The study included 12 patients with congenital pseudarthrosis of tibia and anatomical shortening of 2.5±1.1 cm. The' age of patients ranged from 7 years to 18 years. Blood serum was used for enzyme immunoassay analysis. The own blood serum levels of 103 conditionally healthy individuals (of mean age of 13.0±0.27 years) were considered as the norm. Greater changes in the concentration were detected among vascular endothelial and transforming growth factors. The patients showed imbalance in serum TGF, low reparative potential of bone tissue due to osteoclast activation prevailing over differentiation of osteoblasts, progenitor and mesenchymal cells. Dynamics in serum concentration of IGF at the time of frame removal indicated to terminating osteoblast activation and collagen synthesis and concomitant active bone restructuring.