Study On The Influencing Factors Of Enlarged Resection Combined With Membrane Induction Technique In The Treatment Of Adult Lower Extremity Infectious Bone Defects

Objective: To explore the clinical efficacy and influencing factors of the extensive resection of the lesion combined with membrane induction technology in the treatment of the infected nonunion in long bone shaft of adult lower limbs,so as to provide theoretical and clinical basis for the treatment of the infected nonunion in lower limbs.Methods: A retrospective analysis was performed on a total of 40 adult patients with infected nonunion of long bone shaft in lower limbs treated by the extensive resection of the lesion combined with membrane induction technology in orthopedic trauma department of the first and third affiliated hospitals of our university from May 2016 to August 2018.There were 27 males and 13 females;aged 22-68 years old,with an average age of 39.1years old;22 cases in the thighbone and 18 cases in the shin bone;6 cases were blood-borne infections and 34 cases were post-traumatic infections;17 cases were Cierny-Mader type III,and 23 cases were type ?;23 cases had sinus tract formation before the surgery,and 21 cases had positive culture results of sinus secretions.The treatment was carried out in two stages.In the first stage,the affected limb was fixed after thorough debridement,and the antibiotic-loaded bone cement was implanted in the bone defect to promote the formation of the induced membrane.In the second stage,the bone cement was removed,and the fixation device was replaced,and bone grafting was performed in induced membrane.The infection control in the first stage and bone graft healing in the second stage were recorded.The clinical efficacy was evaluated by the final infection control rate,bone healing time,lower limb function,improvement of quality of life and complications.Statistical analysis was performed on factors(bone defect length,bone graft type,occupying time,Cierny-Mader type,fixation method,cause of disease,age)affecting bone healing time and the improvement rate of lower limb function(the percentage of difference of lower limb function score after and before operation in the highest score).Results: All 40 patients were followed up.The follow-up time was 14-27 months,with an average of 17.2 months.All the patients obtained bone healing successfully.Imaging examination showed that the bone healing time was 16.1-21.6 weeks,with an average of18.53 ± 1.41 weeks.The length of bone defect after debridement in these patients ranged from 5.2 cm to 14.2 cm,with an average of 7.96 ± 2.19 cm;9 cases received stent external fixation,and 31 cases received locking plate internal fixation;18 cases received autogenous bone graft,22 cases received mixed bone graft.Among them,2 patients had a recurrence of infection in the first stage,and the infection was controlled after extendingdebridement and changing antibiotic-loaded bone cement again;there was no recurrence of infection in the second stage.The average lower limbs function score and quality of life score of all patients were significantly higher than those before operation(P < 0.05).There was no significant difference in the time of bone healing among different bone defect length,bone graft type,occupying time,Cierny-Mader type,fixation method and pathogenesis(P > 0.05),which was closely related to different bone defect location and age(P < 0.05).The improvement rate of lower limb function was only correlated with the use of different fixation devices after the first stage operation(P < 0.05),and there was no significant correlation with other factors.The postoperative anchylosis(complication)was mainly related to the use of external fixation(P < 0.05).Conclusion:1.The extensive resection of the lesion combined with membrane induction technology in the treatment of the infected nonunion in adult lower limbs has reliable efficacy,and good infection control effect,which can provide a good microenvironment for bone graft healing,so it is suitable for clinical application and promotion.2.Factors affecting treatment efficacy:Different bone infection site and age can directly affect the healing time of bone graft;the use of plate internal fixation in the first stage operation can effectively prevent anchylosis,and the improvement of lower limb function is better than that of external fixation.3.Different etiology,C-M classification,bone defect length(within a certain range),and occupation time have no significant effect on bone healing time and function improvement.