Published online Jun 18, 2020. doi: 10.5312/wjo.v11.i6.304
Peer-review started: February 26, 2020
First decision: April 25, 2020
Revised: May 6, 2020
Accepted: May 16, 2020
Article in press: May 16, 2020
Published online: June 18, 2020
Segmental long bone defects are one of the challenges in contemporary orthopedic practice due to severity of high-energy trauma, traffic accidents and military activities. Current strategies for their reconstruction [distraction osteogenesis (DO), free vascularized grafting (FVG), and induced membrane technique (IMT)] are based on autogenous type of grafting, either free or non-free, which is their main merit. However, the shortcomings and problems of these methods still remain the issues which restrict their overall use. The Ilizarov non-free bone plasty is a method of DO used with the Ilizarov apparatus which originated in Russia and has been used in other countries since 1990s.
Being experienced in the Ilizarov method of limb reconstruction, we studied the most recent available literature on these three methods for long bone defect and nonunion management to determine the present role of the Ilizarov techniques in this orthopedic field and to investigate the solutions proposed by the authors to the problems they encounter for improving treatment outcomes.
The main objectives were to find scientific material in the databases of orthopedic medical journals and to select suitable articles on the management of segmental long bone defects using current methods that show treatment results, merits, shortcomings, ways to overcome failures and prospective trends for future research in this field. In addition, we searched for original articles that compared the Ilizarov techniques with the methods of IMT or FVG and contained quantitative data on the evaluation of these methods.
Three databases (PubMed, Scopus, and Web of Science) were screened for recent studies in long bone defect and nonunion treatment within a five-year period (2015-2019). Sixty-five full-text clinical articles and reviews in English were selected for data analysis. Clinical studies were included if they described large patient samples (not less than ten cases for congenital, post-tumor resection cases or rare conditions, and more than 20 cases for the remainder) and contained treatment results and complications. Major adverse events involving operative procedures to correct the treatment failure, or its sequelae were of particular interest. Merits, shortcomings and problems of the Ilizarov non-free bone plasty, IMT and free vascularized fibular graft were summarized. Out of a total of 50 articles on DO found, only nine were devoted to bone defects in the upper extremity while infected and aseptic post-traumatic defects of the lower limbs were reported in more than 70% of the articles, infected tibia being the most frequent location.
The search showed that there are numerous studies on long bone defect and nonunion management with DO and IMT. The use of free vascularized fibular graft has been less reported. Full texts of a total of 65 articles using these three techniques including 35 clinical reports on the use of DO or its comparison with two other methods were reviewed for outcome measures. It was found that DO techniques provide solutions to many complex problems as it addresses the triad of problems simultaneously (bone loss, soft-tissue loss and infection). Management of tibial defects mostly utilizes the Ilizarov circular fixator. Monolateral rail fixators are preferable in the femur. The use of a ring fixator is recommended in patients with an infected tibial bone gap of more than 6 cm. High rates of successful treatment were reported by the authors that ranged from 77% to 100% and depended on the pathology and the type of the Ilizarov technique used. Unfortunately, the outcome success rates were heterogeneous and lacked definite statistical findings. Docking site nonunion and after-frame regenerate fracture or deformity were the major causes of failures. One of the solutions to these problems is the application of hybrid external and internal fixation. Most authors currently recommend docking site revisions during bone transport and use supportive bone grafting. Effective technical solutions and add-on therapies to improve quality and control over osteogenesis have been developed.
The main solutions to the problems of DO that are recommended by the authors focus on the following developments: (1) Mechanical stimulation of regeneration; (2) Multifocal bone transport to reduce total treatment time; (3) Acute shortening followed by distraction histogenesis; (4) Gradual transport of a fibular fragment in subtotal and total tibial defects; (5) Bone transport over an intramedullary nail; (6) Hydroxyapatite coated pins; and (7) Intraosseous injection of bone-marrow derived autologous mesenchymal stem cells. There are few comparative clinical studies that evaluate outcomes of the three methods used for long bone defects and nonunion.
The combination of the biological effects of DO and IMT for treating congenital pseudarthrosis of the tibia has been proposed, as both methods promote vascularized new bone formation. New internal telescopic nails have been investigated to provide a one-stage alternative to external or hybrid fixation for reliable DO as they show similar bone formation results, exclude pin-tract infection problems and significantly improve patients’ quality of life. The issues of DO stimulation with cell-based additives and the use of nanostructured materials still require further investigation.