Aseptic nonunion of the tibia about 40 cases

This retrospective study has enabled us to show that the treatment of aseptic nonunion of the tibia by screw plate associated with an autograft bone constitutes an effective therapeutic alternative with very encouraging functional and radiological results. The high incidence of aseptic nonunion on the tibia can be explained by poor tissue coverage and therefore poor blood circulation [6]. Several factors may be involved in the occurrence of aseptic tibial nonunion [7–10]. One of the main factors favoring aseptic nonunion of the tibia remains the technical errors during the initial treatment: persistent interfragmentary gap, insufficient volume of screw plate or insufficient number of screws, insufficient of size or diameter of intramedullary nail and failure of the fixation. We found nine cases (22.5%) of these technical faults in our series. We also noted a clear male predominance (85%), like several series in the literature [12–16], and this peculiarity is thought to be due to male exposure to violent trauma.

The average age of our patients was 41 years (range 28–59 years) which matches the data of the series [12–16], and this age group corresponds to a period when there is a lot travel and professional activity. Road accidents are the main cause (88.4%) of initial fractures [17]; in our patients, this causal agent represents 85% of cases. In our series, the initial open fracture was found in 35 patients (87.5%) with a predominance of type III according to the Gustilo classification; we observed: 10 patients of type I, 4 patients of type II, 18 patients of type IIIA and 3 patients of type IIIB, which agrees with the data in the literature [14–16], and skin opening can be correlated with the decrease in bone healing power as well as the initial bone loss which was observed in 57.5% of patients. On the clinical level, the main symptom is the pain associated or not with a functional impotence or an instability, and this pain is localized at the level of the fracture site, appearing with the mobility or the weight bearing [18]. All of our patients were painful at the PSA focus, which was mobile in 25% of patients. The standard face and profile X-ray remains a simple, noninvasive examination that makes it possible to make the radiological diagnosis of aseptic nonunion of the tibia and to specify its type and site. Seydou [12] and Bouzidi [19] reported that the initial fracture was located at the distal 1/3 of the leg and represented 36% of cases.

In our series, the most common site of aseptic nonunion of the tibia was the middle 1/3 of the leg (55%). Complex fractures make bone healing more difficult, given the comminution that leads to devascularization of one or more fragments and makes mechanical stabilization difficult [20]. Like several series in the literature [21, 22], it was found in our series that atrophic aseptic nonunion is the type most frequently found with a rate of 60%. 52.5% of our patients were initially treated with external fixator (81.8% of patients had external fixator according to [14]), while 40% of our patients had intramedullary nailing (16% of patients had intramedullary nailing according to [23]). [24] presented 2 cases of infection with an external fixator with 1 case of skin necrosis, and we found 2 cases (5%) of superficial infection in patients initially treated with an external fixator, controlled by local care and appropriate antibiotic therapy.

Several treatments are proposed for the management of aseptic nonunion of the leg, the goal of which is to obtain as soon as possible a consolidation of the site of PSA with correction of the axis and the length of the bones, as well as the conservation satisfactory function of the lower limb [18]. Internal fixation by intramedullary nailing is a so-called closed hearth technique [25], allowing the stabilization of the site without periosteal removal. Intramedullary nailing will find its place in hypertrophic PSA without significant alignment disturbance, and the supply of the reamer equivalent to an in situ graft, promotes the formation of the periosteal callus [26]. The major risk of this treatment is contamination of the entire bone in cases of septic nonunion or when placing a nail after an external fixator [26, 27].

External fixation allows stable fixation, compression of the focus and correction of axis disorders [26]. Screwed plate osteosynthesis makes it possible to revive the bone ends, permeabilized the medullary canal and ensures stable osteosynthesis with correction of defective postures [28–30]. This is the only technique making it possible, during the same procedure, to ensure good stabilization of the PSA focus, while providing an osteogenic complement essential for consolidation and to take bacteriological samples from the PSA site. There are several means of stimulating osteogenesis, including cortico-cancellous autograft mainly taken from the iliac bone and which has a role in inducing the consolidation and filling of a bone defect [28], and it can be considered as the gold standard for the treatment of aseptic nonunion of the tibia, [31, 32], with a consolidation rate of 80–85% according to [33]; in our series it is 92.5%. We report potential morbidity at the donor site, quantified in the literature up to 30% [31] (hematomas, chronic pain, infection). Our results are therefore comparable with those of different authors, and we had a minimal septic risk and a satisfactory consolidation rate (92.5%), so this method (screwed plate and cortico-cancellous autograft) constitutes from our point of view an excellent alternative therapeutic for aseptic nonunion of the tibia.