Table 2.

Summary of merits and problems of the methods used for nonunion and bone defect management

Merits	Shortcomings	Problems or adverse events that are considered failures or may cause it
Ilizarov non-free bone plasty
(1) High-quality, biologically normal new bone tissue of massive proportions is generated through distraction osteogenesis; (2) The regenerated bone has good vascularity; (3) The limb is well stabilized with the circular fixator leading to union at the same time; (4) Coexistent bone issues such as deformity correction, equalization of leg length can be addressed simultaneously and effectively; (5) There is no risk of rejection or necrosis of the non-free graft; (6) Soft tissue healing, free tissue transfer after frame placement is possible; (7) The risk of deep infection is low; (8) The method is suitable for both infected and non-infected cases; (9) It is practical in financially constrained cohorts of patients in medical centers; (10) Full weight-bearing is early after the operation; (11) There are no problems of the donor site; and (12) Stimulation with osteoprogenitor cells is possible	(1) Implementation needs trained professionals; (2) The complexity of the Ilizarov apparatus placement necessities its re-arrangements during treatment; (3) Scarring associated with the wires and half-pins as they progress down occurs; (4) Pin-tract infection is frequent; (5) Wearing time of the circular frame is long; (6) Breakage of wires and pins that may results in frame instability; (7) Patients have physical stress due to pain, inconvenience of sleeping and doing hygiene, negative impact on the patients' mental health; (8) There is some risk of joint contractures and the necessity of doing exercise therapy constantly; (9) It is difficult to mount the apparatus in the areas with a large soft-tissue envelope such as the thigh; (10) The method implies frequent postoperative manipulations (change of dressings, radiographic monitoring of bone formation); (11) Bone grafting at the docking site is mostly required; and (12) The cost of the circular fixator ranges a lot and depends upon the country	(1) Frequent pin-tract infection may lead to wire-tract osteomyelitis; (2) Fractures of the regenerate upon frame removal in massive defects are possible; (3) Deformity of the regenerated bone within 3-4 mo upon frame removal may develop; (4) Osteogenesis failure or incomplete osteogenesis due to technical mistakes or low bone regeneration potential may occur; and (5) Failure of union at the docking site may happen
Induced membrane technique
(1) Extensive segmental defects may be bridged; (2) The induced membrane favours osteogenesis as it is vascularized, bioactive and protects the graft from resorption; (3) Suitable for both infected and non-infected cases; (4) Antibiotics may be impregnated locally into the spacer; (5) Stimulation with osteoprogenitor cells during the second stage is possible; and (6) Weight-bearing is possible as bone fragments are stabilized with external or internal fixators	(1) Long period of treatment and several stages of the surgical procedures are necessary; (2) A considerable amount of autogenous graft is needed to fill the bone defect; (3) The average time to bone union is rather long; (4) Intraosseous blood supply is not adequate; (5) Incomplete remodeling of massive grafts is frequent; (6) Leg length discrepancies in large defects cannot be corrected completely due to restricted graft material; (7) Possibility to address gross deformity and leg length discrepancy is limited; and (8) Gross scarring is inevitable	(1) Necrosis and rejection of grafts, especially when allograft is added for graft volume; (2) Pathological fractures in the defect area may happen; (3) An Internal fixator may break or become instable; (4) Re-grafting due to failure of primary graft healing occurs; and (5) Coexistent bone issues such as gross deformity and leg length discrepancy need to be addressed separately following treatment
Free vascularized fibular graft
(1) Defect may be covered with one procedure; (2) Bone union is achieved within the regular terms for fracture treatment; (3) Primary postresection defect grafting due to tumors is effective; and (4) Weight-bearing is possible as bone fragments are stabilized with external or internal fixators	(1) Surgical intervention is executed with two operative procedures and is rather time-consuming; (2) It requires special training as microsurgery is used; (3) It is rather expensive as needs special medication and equipment; (4) Material for grafting is limited; (5) There are problems of donor site, such as pain and ankle joint problems; (6) Extensive scars are inevitable; (7) Graft remodeling may be incomplete due to hemocirculation disorders in a large graft; (8) Limb bracing is required until adequate hypertrophy of the graft; (9) Valgus deformity may develop at the donor site after harvesting the fibula; (10) The procedure is problematic after previous surgeries and if soft tissues are damaged by scars; (11) Gross scarring is inevitable; and (12) Possibility to address gross deformity and leg length discrepancy is limited	(1) Gross vascular problems (thrombosis) may develop and may lead to necrosis, graft rejection and infection; (2) Pathological fractures of massive grafts may develop; (3) Internal fixator break or instability may occur; (4) Failure of grafting due to nonunion is possible; and (5) Coexistent bone issues such as gross deformity correction and equalization of leg length need to be addressed separately following treatment