Study On Minimally Invasive Internal Fixation For Pelvic And Acetabular Fractures

Part I: APQ classification and its reproducibility evaluation for acetabular quadrilateral plate fracturesObjective: As the medial support of articular surface,quadrilateral plate(QLP)is widely involved in acetabular fracture.Currently,the study of pathological anatomy,classification and operation management of QLP fracture is rare.The aim was to propose a classification comprising all previously known fracture types,which will guide surgical management strategies.Methods: This study retrospectively analyzed the data of 1101 patients with acetabular fractures treated at three medical centers between 2011 and 2019.According to the inclusion and exclusion criteria,243 patients with acetabular quadrilateral fractures with complete imaging data were finally included in the study.The APQ classification system for quadrilateral plate fractures integrates the anatomical structures involved(anterior,posterior,and quadrilateral)and the degree of fracture comminuted(complete or incomplete)to define different types.The APQ classification divides quadrilateral plate fractures into four categories: isolated quadrilateral fractures(type Q),anterior column combined quadrilateral plate fractures(AQ type),posterior column combined quadrilateral plate fractures(PQ type),and two-column combined quadrilateral plate fractures(APQ type).Each fracture was divided into two subtypes according to the degree of separation between the quadrilateral plate and the anterior and posterior columns: incomplete fracture(Q1)and complete fracture(Q2).Fractures were classified according to the novel classification system,and inter-and intra-observer reliability(kappa coefficient,k)was investigated by 4 observers to assess the reproducibility of this system.Furthermore,the surgical approaches and fixation methods for each fracture types are described in this study.Results: A total of 243 patients with QLP fractures were recruited into the study,and 165 patients were surgically treated.The intraobserver reliability for the novel classification was excellent with a mean k value of 0.84(range,0.763 to 0.919),and the mean k value of interobserver reliability was 0.762(range,0.626 to 0.876),indicating substantial agreement.The initial patterns of the QLP fractures were described as separation from the anterior and posterior columns.Column fractures of 6 patients could not be classified when using the Judet-Letournel classification.Most of the QLP fractures were treated with an intrapelvic approach,and the buttress plate or screw were used for internal fixation.Conclusion: This study proposed a novel classification system for the QLP fractures,comprising nearly all fracture patterns,with a high reproducibility.The “buttress” fixation of plates and screws might be beneficial to provide effective buttress fixation to the bottom of the acetabulum bowel.Intrapelvic approaches in which the whole QLP could be exposed may be a better option for the treatment of QLP fractures.Part II: Clinical effect of internal iliac approach in the minimally invasive treatment of acetabular fractures involving the quadrilateral plateObjective: The surgical treatment of acetabular fracture has adverse outcomes and high risk,and minimally invasive method is a good way to reduce complications and improve hip joint function.The aim of this study is to investigate the clinical effect of internal iliac approach in the minimally invasive treatment of acetabular fractures involving the quadrilateral plate.Methods: A consecutive cohort of 17 patients with acetabular quadrilateral plate fractures were managed operatively with the approach.Ten patients had anterior column fractures,1 patient had anterior wall fracture,4 patients had transverse fractures and 2 patients had anterior column with posterior hemi-transverse fractures.The inferior half of the pararectus approach was adopted to open the medial window and to access the anterior column and the quadrilateral plate.The anatomical plates were used for internal fixation.Residual displacements were assessed on the postoperative CT scans using a standardized digital method.The surgical details,hip functional outcomes,and complications were noted.Results: All of the patients were operated using the internal iliac approach and the anatomical plates successfully.The mean operative time and blood loss were 90.9 minutes and 334.1 ml,respectively.The average postoperative residual gap and step displacement on CT were 2.9 mm and 0.7 mm,respectively.The radiological outcome was estimated according to the Matta score,ten of the cases were graded anatomical,six were graded imperfect,and one was graded poor.All cases were followed up for 12 ~ 27 months,with an average of 15 months.Functional outcomes were excellent for nine,good for six,and fair for two.It was noted that one case of peritoneal injury was repaired intraoperatively,without any adverse reactions.Conclusions: The novel internal iliac approach has the advantages of less trauma,direct exposure to the anterior column and quadrilateral plate.The anatomical plates can fit with the surface of the acetabulum,which saves the time of remodeling plates during operation and facilitate fracture reduction.This minimally invasive surgery may provide a good choice for the treatment of quadrilateral plate fractures.Part III: Clinical effect of 3D printing combined with Union plate anatomical plate in the treatment of acetabular quadrilateral plate fracturesObjective This study aims to explore the feasibility and safety of 3D printing-assisted acetabular posterior column screw placement,and to evaluate the early clinical results combined with Union plate anatomical plate in the treatment of acetabular quadrilateral plate fractures.Methods From June 2018 to August 2019,the data of 15 cases of acetabular quadrilateral plate fractures treated with 3D printing planning posterior column screws and new anatomical plates were retrospectively analyzed,including 3 cases of transverse,2 cases of T-shaped,2 cases of anterior and posterior semi-transverse,and 8 cases of both column fractures.According to the preoperative CT data,the whole life-sized pelvis was printed in 3D.Before operation,the placement channel of the posterior column lag screw was planned on the 3D pelvic model.When combined with the fixation of the new anatomical plate on the model,the surgical fixation process was simulated,the caster angle,camber angle and relative distance of the posterior column screw were measured.The supra-ilioinguinal approach were used and supra-pectineal quadrilateral surface buttress plate and posterior column lag screw were used for fixation.The operation time,blood loss and other related data were recorded.The fracture reduction quality and hip function were evaluated by Matta score and the modified Merle D’Aubigne Postel score,respectively.Results The operations of all patients were carried out successfully.The average caster angle of posterior column screw was 58.3 °,the camber angle was 39.2 °,the average distance from sacroiliac joint and arcuate edge was 2.3 cm and 1.2 cm respectively.The average operation time was 172 min(150 ~ 290 min),and the average blood loss was 620 ml(200 ~ 1500 ml).All posterior column screws were successfully placed.The evaluation of reduction quality was excellent in 9 cases and good in 6 cases,with an excellent and good rate of 100%.The hip function score was excellent in 8 cases,good in 5 cases and fair in 2 cases,with an excellent and good rate of 86.7%.Obturator nerve paralysis occurred in 1 case during perioperative period,which improved after 3 months of follow-up.No complications such as incision infection,thrombosis,screw loosening or fracture were observed.Conclusion Simulating operation and planning posterior column lag screw through preoperative 3D printing can effectively improve the success rate of posterior column screw placement.Combined with the new acetabular anatomical plate,it has a good clinical effect in the treatment of acetabular quadrilateral plate fractures.3D printing technology combined with the new anatomical plate is a reliable strategy to improve the treatment safety and surgical efficiency of acetabular quadrilateral plate fractures.Part IV: Clinical study on percutaneous minimally invasive treatment of pelvic and acetabular fractures with external guide templateObjective: To explore the clinical efficacy and safety of minimally invasive percutaneous therapy assisted by external guide plate and conventional methods in the treatment of pelvic and acetabular fractures.Methods: The clinical and follow-up data of 39 cases with pelvic or acetabular fractures treated from June 2016 to February 2018 were retrospectively analyzed.Patients were divided into external guide template group(21 cases)and freehand nailing group(18 cases).Operation time,fluoroscopic frequency and frequency of guide wire adjustments were recorded in the two groups.The postoperative imaging results were classified by Matta criteria,the screw penetration rate was evaluated by CT,the pelvic function was evaluated by Majeed score,and the acetabular function was evaluated by modified Merle D’Aubigné score.The occurrence of complications was recorded.Results:All 39 patients were followed up with an average of 11.6 months(range,9 to 13 months).A total of 42 and 35 screws were placed in the external guide template group and in the freehand nailing group,respectively.In the external guide template group,the operation time was(43.8±22.2)min,the radiation frequency was(29.6±10.7)times and the times of guide needle adjustments was(1.8±1.2)times less than those in the freehand nailing group(73.8±22.6)min,(54.6± 16.5)times,(9.8±2.8)times,the difference was statistically significant(P<0.05).The screw penetration rates of the two groups were 7.1%(3 grades 1)and 14.3%(4 grades 1 and 1 grade 2),respectively.The satisfaction rates of Matta criteria were 90.5%(19/21)and 83.3%(15/18),respectively,the excellent rate of Majeed score at the last follow-up was 88.2%(15/17)and 85.7%(12/14),respectively.The excellent rate of modified Merle D’Aubigné score was 100%(4/4)and 75%(3/4),respectively.There was no significant difference between the two groups(P>0.05).One case of unilateral foot dorsal numbness occurred in the free-hand nailing group and the symptom disappeared at 3 months follow-up.No complications such as neurovascular injury occurred in the external guide template group.Conclusion: The external guide template could reduce radiation frequency,save operation time and improve the accuracy of screw placement.It offers a new solution for minimally invasive treatment of pelvic and acetabular fractures.