ASSESSMENT OF BONE REMODELLING AFTER RECONSTRUCTION OF CRITICAL-SIZE BONE DEFECTS IN TIBIA AND FEMUR USING THE MASQUELET TECHNIQUE: PRELIMINARY RESULTS WITH A MINIMAL FOLLOW-UP OF TWO YEARS

Aim The induced membrane technique (IMT) is a validated procedure for the treatment of infected bone defect with critical size bone loss. High rate of bone fusion is reported with IMT, but questions remain regarding the quality of the healing bone and the bone remodeling. The aim of this study was to develop a method to describe and assess bone remodeling after IMT. Methods We conducted a retrospective monocentric study between september 2007 and august 2023 including all patients treated for a critical size bone defect of the femur or tibia with the IMT. Patients with a minimal follow-up of 2 years after first stage and bone union achieved 18 months after 2nd stage were included. Bone remodeling was assessed 2 years (and 5 years when possible) after 1st stage by 1 senior and 1 junior surgeon using an experimental score developed by our team. The score included 4 items that describe aspects of the reconstructed bone : homogeneity of the graft-bone junction zone, bone density of the grafted area compared to the adjacent healthy bone, cortico-medullary differentiation, overall appearance of the tibia or femur compared to normal anatomy. Additional score of those 4 items gives a total score from 2 to 14, 14 being a reconstructed bone area similar to physiologic bone anatomy of the patient. Results Bone remodeling was assessed at 2 years after surgery for 22 patients with a mean bone remodeling score of 10/14 points (7/14 - 12/14) 0,11. Evaluation at 5 years after surgery was possible for 7 patients with a mean score of 11/14 points (8/14-13/14) 0,11.The bone remodeling score was performed at 2 and 5 years successively for 6 patients with an amelioration of 1 to 5 points for 5 of them. Tibias and femurs had similar scores at 2 (p<0,792) and 5 years (p<0,496). All patients that had a bone remodeling score > 9/14 did not present complications regarding bone union during their follow-up. Conclusion The bone remodeling score shows interesting preliminary results. A high score > 9/14 is associated with better results regarding bone union. Those findings require further investigations to obtain validation of the score and to evaluate the impact of differents types of osteosynthesis on bone remodeling.