A Modified Nailing Approach Of INFIX And Its Clinical Application In Pelvic Fracture

Background and ObjectiveINFIX is a minimally invasive technique for the treatment of pelvic anterior ring fracture.However,while effectively fixing the anterior pelvic ring,it easily made the lateral femoral cutaneous nerve(LFCN)suffers an injury,which affected the therapeutic effect.Usually,INFIX choose space between the tensor fascia lata and sartorius muscles as its nailing approach,which too close to the LFCN and could damage it potentially.If make the INFIX nailing approach medially,the safety and efficacy of space between the sartorius and iliopsoas muscles were unknown.Therefore,our study was aimed to explore the feasibility of INFIX nailing approach into space between the sartorius and iliopsoas muscles by measuring the anatomical parameter relative to the safe distances of LFCN and femoral never(FN)in the two spaces above.Then,using the modified INFIX nailing approach into the treatment of pelvic fracture,and evaluating its clinical application.MethodsFirstly,on the gross specimens,we anatomized and measured the distances from the medial and lateral margin of sartorius muscle to LFCN and FN,and the distances from anterior inferior iliac spine(AIIS)to the medial and lateral margin surface of sartorius muscle.In the inguinal region,we also measured the distances from the exit pelvic point of LFCN to anterior superior iliac spine(ASIS)and AIIS,and the distance from ASIS to the surface projection of AIIS and the pubic tubercle.The differences and relevance of all the anatomical parameters were analyzed by statistic methods such as t-test and linear regression.Secondly,the clinical data of 17 pelvic fracture patients treated through the modified INFIX nailing approach were collected from April 2016 to April 2019.Evaluation of clinical efficacy depends on the changes including the pelvic deformity index(PDI)and the width of pubic symphysis before and after INFIX,as well as the initial weighting time,the fracture healing time,the time to remove INFIX and the Majeed score after surgery.Complications include the injuries to LFCN and FN,the infection of incisions,and so on.ResultsIn the anatomical measuring,the distance from medial margin of sartorius to LFCN increased 7.71mm(p<0.01),and to FN was still remained 22.36mm compared to the lateral margin.And compared to the lateral margin surface of sartorius muscle,the distance from AIIS to the medial surface decreased 8.96mm(p<0.01).In the inguinal region,there is no statistical difference between the distances from the exit pelvic point of LFCN to ASIS and AIIS.And the distance from ASIS to the surface projection of AIIS is approximately 1/4 of the distance from ASIS to the pubic tubercle.In the clinical application,After INFIX,the PDI decreased 1.63%(P<0.01),the width of pubic symphysis decreased 5.91mm(p<0.05).The average initial weighting time was 9.86 weeks,the fracture healing time was 14.07 weeks,the time to remove INFIX was 26.75 weeks,and the Majeed score was 88.57.There was no injury to LFCN or FN,two patients had incisional infection,and one patient had hypogastrium subjective discomfort.ConclusionThe INFIX nailing approach into space between the sartorius and iliopsoas muscles had the feasibility in both the anatomy and clinical application.It could reduce the injury to LFCN,and did not affect the femoral neurovascular bundle,which was all minimally invasive,safe and effective in the treatment of pelvic fracture.