Both‐column Acetabular Fractures with Posterior Wall Involved can be Managed through Single Anterior Approach by Evaluation of Computer‐assisted Virtual Surgery Technique

Abstract

Objective

Posterior wall (PW) fractures were sometimes associated in both‐column acetabular fractures. How to evaluate pre‐operatively the necessity for the performance of the posterior approach was an issue to be solved. In order to solve this issue, the computer‐assisted virtual surgery technique was used to evaluate if the involved PW in both‐column acetabular fractures (BACF) should be managed through posterior approach and verify the feasibility of this method.

Methods

Data of a consecutive cohort of 72 patients with both‐acetabular fractures from January 2012 to January 2020 was collected for retrospective study, of which 44 patients had concomitant acetabular PW fractures, and patients without PW fractures were labeled as the BCAF group. Computer‐assisted virtual surgery technique was performed pre‐operatively to evaluate the necessity for performance of posterior approach in 44 patients, and posterior approach was required if more than 3 mm of displacement was still present in the reduced 3D model. The 23 patients without treatment through posterior approach were labeled as the BCAF‐PW⁻ group, and the 21 patients with treatment through posterior approach were labeled as the BCAF‐PW⁺ group. Operation‐related and post‐operative parameters were recorded. The quality of reduction and functional outcomes were assessed by the Matta scoring system and modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t‐test of independent samples and rank‐sum test of ranked data between every two groups. Also, the one‐way analysis of variance (ANOVA) was used to analyze data between the three groups.

Results

Comparing operation‐related and post‐operative parameters in the three groups, some PW fractures in both‐column acetabular fractures could be ignored, and which could be evaluated pre‐operatively for necessity of an additional posterior approach. Operative time (271.2 ± 32.8 mins) and intra‐operative blood loss (1176.7 ± 211.1 mL) were significantly higher in the BCAF‐PW⁺ group. The excellent/good of reduction (25/28 of the BCAF group, 21/23 of the BCAF‐PW⁻ group, 19/21 of the BCAF‐PW⁺ group) and functional outcomes (24/28 of the BCAF group, 18/23 of the BCAF‐PW⁻ group, 18/21 of the BCAF‐PW⁺ group) of three groups were similar. The incidence of complications, such as deep vein thrombosis (4/28 of the BCAF group >3/23 of the BCAF‐PW⁻ group >1/21 of the BCAF‐PW⁺ group) and injury of lateral femoral cutaneous nerve (3/23 of the BCAF‐PW⁻ group >2/28 of the BCAF group >0/21 of the BCAF‐PW⁺ group), was no significant difference.

Conclusion

The partial both‐column acetabular fractures with PW involvement could be managed through a single anterior approach without another posterior approach by evaluation of computer‐assisted virtual surgery technique.

The method to evaluate if the posterior wall fractures should be treated in both‐column acetabular fractures.

Introduction

Acetabular fractures were classified into five elementary and five associated patterns according to Letournel's classification, three of which involved acetabular posterior wall (PW) such as PW fractures, posterior column associated with PW fractures, and transverse associated with PW fractures. ¹ , ² However, the both‐column acetabular fractures with PW involvement (BCAF‐PW) were not described in Letournel's classification, which was more severe and accounted for 34.8% of both‐column acetabular fractures (BCAF). ³ This type of injury mostly occurred in high‐energy trauma in 87.4% of cases, especially for traffic accidents. ³ , ⁴ , ⁵ The spatial direction variability of the acetabular fractures, especially in complex acetabular fractures, made it quite difficult for the orthopedic surgeon to manage and select suitable surgical approaches and the available implants, which required experienced understanding of fracture patterns. However, regardless of the acetabular fracture patterns, restoration of anatomic reduction of the articular surface with stable fixation remained the gold standard of treatment. ⁶

The management of PW fractures was also crucial because the PW carried articular surface and affected the stability of the acetabulum, in addition, the quality of its reduction directly affected the outcome of functional recovery. ⁷ , ⁸ Therefore, the combined anterior–posterior approach was performed as the preferred surgical method of most orthopedic surgeons, ⁹ , ¹⁰ , ¹¹ which allowed for direct visualization of the fracture fragments but resulted in longer operative times and higher occurrence risk of postoperative complications. Owing to the difference in the injury mechanism of BCAF‐PW with the common PW fractures within the Letournel's classification, the involved PW fragment in BCAF was intact and independent, and the joint capsule was also intact. ⁵ , ¹² Therefore, the involved PW in BCAF might be more stable than the common PW fractures.

Most surgeons suggested that the complex acetabular fractures should best be treated by a single approach to reduce the iatrogenic damage for patients, and the combined approaches should be performed when the quality of reduction was not possible to achieve by a single approach. Wang et al. ⁵ managed BCAF‐PW by modifying the extended iliofemoral approach or by using the lateral extension of the ilioinguinal approach with lag screws to fix the involved PW, but they could only be performed in cases with PW fractures without significant displacement. Shin et al. ¹² determined the need for management of residual PW of BCAF by evaluating the continuity of the acetabular rim in 3D images after the reduction of anterior acetabular fractures in a first surgery, but this method could prolong the hospital stay or even delay the treatment of patients with PW fractures requiring management. Therefore, some special BCAF‐PW could be managed through a single anterior approach without management of the involved PW according to the above.

Which types of BCAF‐PW could be managed through single anterior approach? The key to decide if the involved PW should be managed was the quality of reduction, but it was difficult to evaluate pre‐operatively. Therefore, a new method needed to be proposed to assess if it was necessary to manage the involved PW in both‐column acetabular fractures (Fig. 1). Recently, computed tomography imaging technology and digital orthopedic surgery methods were applied widely in clinical practice, and some studies reported that the application of computer‐assisted virtual surgery procedure before operation obtained satisfactory clinical outcomes in acetabular fracture surgery. ¹³ , ¹⁴ This technique allowed surgeons to better identify the spatial relationship between different fracture fragments, determine the sequence of reduction, and select the most appropriate implants and surgical approach. ¹⁵ , ¹⁶ Therefore, we applied the computer‐assisted virtual surgery technique to pre‐operatively evaluate the surgical method for BCAF and determined if the involved should be managed in BACF. The fracture fragments except the involved PW were reduced first using computer‐assisted virtual surgery technique, and if an additional posterior approach was needed, it was evaluated based on the spatial relationship between the PW and the surrounding reduced fragments after successful reduction.

Fig. 1.

(A, B) 3D reconstruction of a patient with BCAF‐PW. (C) The red lines show that the involved PW might be reduced as the other fractures are reduced, which seems to show that the involved PW can be managed through single anterior approach. It is difficult to decide if the involved wall can be managed through the single anterior approach by visual perception.

The purposes of this study were: (i) to propose a new method to evaluate if the involved PW in BACF should be managed; (ii) to verify the feasibility of this method; and (iii) to compare the clinical data of the patients with BCAF‐PW managed by single approach with the patients with BCAF but without PW fractures and the patients with BCAF‐PW managed by dual approaches for better understanding.

Patients and Methods

Inclusion and Exclusion Criteria

Patients with the following conditions below were included: (i) BCAF with treatment through single anterior approach; (ii) BCAF‐PW, and (iii) followed more than 12 months. Patients with the following conditions below were excluded: (i) delayed fractures (≥21 days); and (ii) age at the time of injury ≤18 years.

This retrospective case–control study was approved by our institutional and national research committee (S1060) (Fig. 2). Data of patients who underwent surgical treatment for acetabular fractures from January 2012 to January 2020 were reviewed. According to above inclusion and exclusion criteria, 72 patients admitted in our department were enrolled in this study. Patients were divided into three groups: the first group consisted of 28 patients who were BCAF (the BCAF group); the second group comprised of 23 patients who were BCAF‐PW that managed through anterior approach only (the BCAF‐PW⁻ group); the third group comprised of 21 patients who were BCAF‐PW that managed through both anterior and posterior approaches (the BCAF‐PW⁺ group). The patient demographics and characteristics were described (Table 1).

Fig. 2.

Study flow diagram. Patients with BCAF were included in this study. Patients with the conditions (delayed fractures ≥21 days, age at the time of injury ≤18 years) were excluded; patients with the conditions (BCAF with treatment through single anterior approach; BCAF‐PW; Followed more than 12 months) were included. Twenty‐eight patients who were BCAF treated with the single anterior approach and 44 patients who were BCAF associated with PW involved were selected.

TABLE 1.

Patient demographics.

Variable	BCAF group (n = 28)	BCAF‐PW− group (n = 23)	BCAF‐PW+ group (n = 21)	P‐value
Age (years)	44.8 ± 14.1	42.5 ± 13.1	41.7 ± 12.3	0.701
Gender (Male: Female)	16:12	14:9	13:8	0.939
Injury to operation (day)	9.4 ± 4.4	9.5 ± 3.5	8.0 ± 3.6	0.374
Operative time (min)	162.5 ± 21.2*	178.7 ± 35.1#	271.2 ± 32.8*, #	< 0.05
Blood loss (mL)	702.9 ± 142.7*	803.5 ± 192.6#	1176.7 ± 211.1*, #	< 0.05
Matta
Excellent	19	14	11	0.855
Good	6	7	8
Poor	3	2	2
Merle
Excellent	11	9	11	0.701
Good	13	9	7
Fair	4	4	2
Poor	0	1	1
Complication
DVT	4	3	1	0.552
LFCN	2	3	0	0.243

Notes: *, # Significant difference, P < 0.05, One‐way ANOVA was used to evaluate the difference between the three groups except for Operative time and Blood loss.

Pre‐operative 3D Simulation

The thin‐slice computed tomography (Siemens, Germany; 64‐row spiral CT with 1‐mm layer thickness) scan was requested for each group of patients before operation. The CT data of the BCAF‐PW⁻ and BCAF‐PW⁺ group were collected and imported into Mimics 20.0 software (Materialise, Leuven, Belgium) in Digital Imaging and Communications in Medicine (DICOM) format. Each separated fracture fragment was differentiated and labeled with different colors in cross‐sectional view of the CT, converting each fragment to an individual object. The fracture model was then transferred to 3D. Every individual fragment could be permitted to move and rotate randomly (Fig. 3A–C). First, we mirrored the acetabulum on the healthy side as a template for reducing the affected side, and then the visual reduction procedures were performed of all fragments except additional operations for PW (Fig. 3D–F). Subsequently, if a displacement (>3 mm) was found, the PW needed to be managed by an additional posterior approach. Conversely, no additional treatment was required.

Fig. 3.

(A–C) Each fracture fragment is separated and label with different colors. (D–F) All fragments are reduced, but the involved PW clearly needs to be managed.

Surgical Technique

All patients involved in this study were given verbal communication and signed informed consent before surgery. A flat radiolucent operative table was used for each patient so that fluoroscopy could be performed conveniently in all positions. After patients received appropriate anesthesia, different surgical positions were selected depending on the type of injury and the pre‐operative reduction consequence of computer‐assisted virtual surgery technique. All patients in the BCAF group where the PW was not involved and patients in the BCAF‐PW⁻ group that the involved PW did not require additional posterior approach to manage (Fig. 4). Patients in the BCAF‐PW⁺ group were required to transform position to facilitate the management of the PW after successful reduction of BCAF through the anterior intra‐pelvic approach according to the designation of pre‐operative computer‐assisted virtual surgery technique (Fig. 5). The anterior and posterior approaches performed in this study were the supra‐ilioinguinal ¹⁷ and Kocher–Langenbeck (KL) approach, ¹⁸ respectively. Patients were made to lie in the supine position with the surgeon standing on the opposite side of the affected side, when the anterior intra‐pelvic approach was performed. For the patients who needed management of PW were transformed into a lateral position after the BCAF was finished. Drainage tubes were placed after operation depending on the number of surgical incisions, one for one incision. Post‐operative drainage was determined by the drainage status and usually removed after 3 days. All patient received intravenous antibiotics for 3 days after operation. Low‐molecular heparin was required for each patient during hospitalization to prevent the formation of deep vein thrombosis in the lower extremities. Patients with a posterior approach required oral indomethacin for 6 weeks postoperatively to counteract ectopic ossification.

Fig. 4.

One case: a 30‐year‐old male patient who sustained a fracture of BCAF‐PW. (A) Pre‐operative antero‐posterior radiograph. (B–D) Pre‐operative 3D reconstruction of fracture pattern. The red arrow represents the PW and the black arrow represents the reduction direction of posterior column/wall, which is same. (E) Pre‐operative CT scan. Blue arrow represents the involved PW. (F) Pre‐operative reduction simulation. (G) Post‐operative CT scan. White arrow represents the reduced PW. (H–J) Post‐operative antero‐posterior and Judet oblique views.

Fig. 5.

A patient who should be managed through anterior and posterior approach. (A) Pre‐operative X‐ray radiograph. (B) 3D reconstruction before reduction. (C, D) Pre‐operative reduction showed that the involved PW was still separated after the other fractures were reduced. (E) Pre‐operative CT showed the involved PW. (F) Post‐operative CT showed the involved PW was reduced and fixed. (G–I) Post‐operative X‐ray radiograph.

Non–weight bearing exercises were performed on the bed within 4 weeks postoperatively, such as passive and active ipsilateral hip flexion or extension motion. Patients were allowed to walk with a pair of crutches 4–6 weeks after operation and with a single crutch 6–12 weeks after operation.

Data Collection

Data of pre/post‐operative radiography including X‐ray and CT scan were collected to assess the fracture patterns, surgical plan and quality of reduction. Follow‐up examination was performed at 1 month, 3 months, 6 months, 1 year postoperatively and yearly thereafter to evaluate degree of fracture healing and function in the outpatient department or by telephone.

The Matta criteria ¹⁹ were used for evaluating quality of reduction on X‐ray that was taken immediately after surgery by a senior surgeon who was not involved in the surgical care. The scores were categorized as anatomic (0–1 mm), good (2–3 mm), or poor (>3 mm) based on millimeters of residual displacement.

The Modified Merle d'Aubigné score ²⁰ was used for functional outcome evaluation assessed by an independent orthopedic surgeon who was not involved in the definitive care or surgery at final follow‐up. The scores were categorized as excellent (18 points), good (15–17 points), fair (14 or 13 points), or poor (<13 points).

A standardized procedure was performed to measure greatest residual step and gap displacement of post‐operative CT in any of the axial, sagittal or coronal plane views within the BCAF‐PW⁻ and BCAF‐PW⁺ group. ²¹ A circular template was drawn to fit along the acetabular articular surface and the gap displacement was measured along its perimeter. The step was measured between the distance from the maximum displacement point of the fragment to the center of the circle and the radius.

Statistical Analysis

Statistical analysis was performed using SPSS version 22.0 (SPSS Inc., Chicago, IL, USA). Descriptive data was used to present the clinical characteristics. Continuous variables were presented as mean ± SD. Comparisons of data between every two groups were performed using t‐test and rank‐sum test, which depended on the characteristics of data. The one‐way analysis of variance (ANOVA) was used to analyze data (Age, Gender, Injury to operation, Blood loss, Matta, Merle, Complication, CT measurement) between the three groups. P < 0.05 was accepted as Statistical signification deference.

Results

General results

All patients in this study were followed up at least for 1 year at 1, 3, 6 months and 1 year postoperatively, and then annually thereafter. Of the three groups, the average time to operation was 9.4 ± 4.4 days in the BCAF group, 9.5 ± 3.5 days in the BCAF‐PW⁻ group and 8.0 ± 3.6 days in the BCAF‐PW⁺ group (P = 0.374). The male/female ratio was 16:12 for the BCAF group, 14:9 for the BCAF‐PW⁻ group and 13:8 for the BCAF‐PW⁺ group (P = 0.939). The mean age of the BCAF group was 44.6 ± 14.1 years, and that of the BCAF‐PW⁻ and BCAF‐PW⁺ group was 42.5 ± 13.1 years and 41.7 ± 12.3 years, respectively (P = 0.701). There was no statistically significant difference between the three groups, which represented the comparability was practicable in other assessment parameters between the three groups (Table 1).

Operation‐related Parameters

The average operative time was 162.5 ± 21.2 mins in the BCAF group, 178.7 ± 35.1 mins in the BCAF‐PW⁻ group, 271.0 ± 32.8 mins in the BCAF‐PW⁺ group, and there was statistically significant correlation between the BCAF‐PW⁺ group and the BCAF or the BCAF‐PW⁻ groups. Also, the average blood loss was also higher in the BCAF‐PW⁺ group (1176.7 ± 211.1 mL) comparing with the BCAF (702.9 ± 142.7 mL) and the BCAF‐PW⁻ groups (803.5 ± 192.6 mL), which was statistically difference between the BCAF‐PW⁺ group and the BCAF or the BCAF‐PW⁻ groups (Table 1).

Quality of reduction and functional outcomes

Anatomical reduction, good reduction, and poor reduction on the radiograph assessment were evaluated in 19 (67.9%), 6 (21.4%), 3 (10.7%) patients in the BCAF group, 14 (60.9%), 7 (30.4%), 2 (8.7%) patients in the BCAF‐PW⁻ group, and 11 (52.4%), 8 (38.2%), 2 (9.5%) patients in the BCAF‐PW⁺ group, respectively, according to the Matta scoring system. According to the Merle d'Aubigné scores, the functional outcomes at the last follow‐up were excellent in 11 cases (39.3%), good in 13 cases (46.4%%), fair in four cases (14.3%) for the BCAF group, excellent in nine cases (39.1%), good in nine cases (39.1%), fair in four cases (17.4%), poor in one case (4.3%) for the BCAF‐PW⁻ group, and excellent in 11 cases (52.4%), good in seven cases (33.3%), fair in two cases (9.5%), poor in one case (4.8%) for the BCAF‐PW⁺ group, respectively. But there was no statistically significant difference between the three groups (Table 1). The mean residual gap and step displacement of fractures was 3.4 ± 1.3 mm and 0.7 ± 0.4 mm in the BCAF group, 3.5 ± 1.4 mm and 0.8 ± 0.5 mm in the BCAF‐PW⁻ group, 3.7 ± 1.9 mm and 0.8 ± 0.4 mm in the BCAF‐PW⁺ group, respectively (Table 2).

TABLE 2.

Postoperative CT measurements (mm)

CT measurement	BCAF group	BCAF‐PW− group	BCAF‐PW+ group	P‐value
Mean gap	3.4 ± 1.3	3.5 ± 1.4	3.7 ± 1.9	0.885
Mean step	0.7 ± 0.4	0.8 ± 0.5	0.8 ± 0.4	0.622

Note: One‐way ANOVA was used to evaluate the difference between the three groups.

Complications

Complications included postoperative deep vein thrombosis (DVT), which occurred in four (14.3%) patients, three (13.1%) patients, one (4.8%) patient in the BCAF, the BCAF‐PW⁻ and the BCAF‐PW⁺ groups, respectively. And lateral femoral cutaneous nerve injury (LFCNI) occurred in two (7.1%) patients, three (13.4%) patients in the BCAF and the BCAF‐PW⁻ groups, respectively, all recovered completely within 6 months after surgery (Table 1).

Discussion

In this study, we determined whether PW involved needed to be managed through posterior approach in BCAF by pre‐operative computer‐assisted virtual surgery technique. We compared the results of patients with PW involved in BCAF that was managed with the posterior approach or not with those patients without PW involved in consecutive series and found that if the relative spatial position of PW and posterior column did not change/the reduction direction was same, the involved PW in BCAF could be reduced through the anterior approach.

Analysis for Occurrence Reasons of BCAF‐PW

BCAF‐PW is a special type of pattern beyond the Letournel acetabular classification, and the injury mechanism by which the involved PW differs from that of common acetabular PW fractures. BCAF‐PW is caused by high‐energy violence causing the femoral head to impact the acetabulum and often associated with central dislocation. ⁵ Common acetabular PW fractures are caused by direct impact of the femoral head and often classified into three patterns due to the strength and direction of the force, and often associated with posterior dislocation. ²² , ²³ Therefore, the degree of PW injury in BCAF tends to be individual and intact, which is similar to simple (Type I) PW fractures. However, common PW fractures are caused by direct impact of the femoral head resulting in severe injury of posterior capsule and surrounding soft tissues, which can lead to hip instability if reconstruction is not performed. ²⁴ In BCAF‐PW, the femoral head does not directly impact the PW, whose posterior joint capsule and soft tissues are mostly intact, which makes the PW fragment less displaced or even non‐displaced by referring to the posterior column, and the continuity of the acetabulum can be restored after successful reduction of the BCAF. However, how to accurately evaluate whether PW fragments after successful reduction of BCAF need to be managed before operation. In this study, we compared the prognosis between the BCAF‐PW⁻ and the BCAF‐PW⁺ group of patients and found that the quality of reduction (Excellent/Good: 21/23 in the BCAF‐PW⁻ group, 19/21 in the BCAF‐PW⁺ group) and functional outcomes (Excellent/Good: 18/23 in the BCAF‐PW⁻ group, 18/21 in the BCAF‐PW⁺ group) are generally similar. This suggests that this method is feasible for determining whether the PW needs to be managed in BCAF. Comparing the reduction and functional outcomes data from the BCAF group with the BCAF‐PW⁻ group of patients revealed that partial PW fragment in BCAF can be disregarded skillfully. This finding is also similar to the results published by previous studies. Besides, on postoperative CT scans, the mean residual gap (P = 0.885) and step displacement (P = 0.622) was no significant difference within these three groups (Table 2).

General Approaches to Treat BCAF‐PW

BCAF is an inherently complex pattern where the pelvis and the acetabulum are injured simultaneously, and the sequence of reduction also plays a crucial role in prognosis. ¹³ The basis for reduction and fixation is to achieve direct exposure of the fracture position, hence, the choice of approach is critical. Traditionally, BCAF is managed through a single anterior intra‐pelvic approach, such as the modified Stoppa approach, ²⁵ the pararectus approach, ²⁶ and the supra‐ilioinguinal approach. ¹⁷ However, once the PW fracture is involved, it is necessary to consider whether to combine a posterior approach. Some authors have suggested that fixation of injured PW through single anterior approach in BCAF is feasible or can be skillfully ignored according to hip‐joint‐congruency, ²⁷ which avoids the additional posterior approach and reduces the risk of heterotopic ossification as well as surgically relevant indicators. This is also confirmed in our study, the operative duration time (162.5 ± 21.2/178.7 ± 35.1 < 271.0 ± 32.8 mins) and blood loss (702.9 ± 142.7/803.5 ± 192.6 < 1176.7 ± 211.1 mL) are lower in groups managed with a single approach (Table 1). It has to be acknowledged that the dual approach allows direct exposure of the fracture position and achieves anatomical reduction, but it also increases the risk of operation‐related complications. Therefore, which patients with BCAF‐PW require additional posterior approach for management of PW. Our study skillfully addressed this issue by simulating the fracture fragment reduction through computer‐assisted virtual surgery, which avoids an unnecessary approach in some patients with BCAF‐PW.

Reasons of Ignoring the Management of PW Fractures through the Posterior Approach in BCAF

Generally, PW fractures require the posterior approach to be managed. However, in this study, indirect reduction of PW was achieved by directly reducing acetabular anterior fractures through the anterior intra‐pelvic approach (especially the posterior column). First, common PW fractures are caused by direct impact of the femoral head, which results in simultaneous disruption of posterior capsule, ligaments, and muscles. These soft tissues have indirect role in maintaining the position of the bone fragment, whose disruption results in displacement of the PW fracture fragment, changing the spatial position of the PW to the posterior column. Therefore, in some previous studies, these soft tissues need to be repaired after the common PW fracture has been reduced. ²⁸ In BCAF‐PW, although the separation of the entire acetabulum is severe, the integrity of the posterior soft tissues allows for no significant change in the spatial relative position of PW fragments to the posterior column/reduced posterior column, which makes indirect reduction of PW fragments due to direct reduction of BCAF feasible. PW is just like an appendix to the posterior column, the reduction of column provides frame structure for wall reduction. If the wall/column fractures are simultaneous and reduced in same direction, it is possible to successfully reduce the wall at the same time as the reduction of column is achieved. Furthermore, the integrity of the surrounding soft tissues plays an important role in the stability of hip joint. Therefore, the integrity of the posterior soft tissues is also a factor in ensuring that the PW does not need to be managed through the posterior approach in this study.

Which PW Fractures Could be Ignored in BCAF

Examination under anesthesia is still the “gold standard” for assessing hip stability in patients with PW fractures, ²³ but it is noted that smaller PW fracture fragments have better hip stability to ensure that the residual PW prevents posterior dislocation of femoral head. ²⁹ , ³⁰ , ³¹ In many studies, the quality of reduction has been found to be determinative prognosis. ⁷ In addition, the severity of PW fractures also has an impact on the prognosis, with more than two fragments of the PW having worse prognosis than the simple PW fractures. ³² However, all of the above observations are in regard to common PW fractures. In BCAF‐PW, the femoral head is centrally dislocated and the posterior soft tissues are intact, which makes posterior dislocation almost impossible. In addition, in BCAF‐PW, the PW fragment is independent, which results in no significant difference in prognosis between the three groups (P = 0.701). However, in the cases of PW fractures with more fragments or severe articular surface impaction, posterior approach is still recommended to be performed to prevent severe postoperative traumatic arthritis. In this study, the functional outcomes of the PW not managed by the posterior approach was similar to that of the PW managed (P > 0.05). This result further illustrates the feasibility of this method.

Role of Pre‐operative Computer‐assisted Virtual Surgery Technique in Treating BCAF‐PW

In this study, the pre‐operative computer‐assisted virtual surgery technique played a very important role in the selection of the surgical plan. It is similar to the reports of other studies, the application of this technique in orthopedics was very valuable. Chen et al. ³³ used 3D printing technology to print the mirror model of the contralateral side for shaping of the plate before operation, which greatly reduced the operation time and blood loss during operation. Wan et al. ¹³ used pre‐operative computer‐assisted virtual surgery technique to simulate the reduction of the fracture fragments, and planned the position of the plate placement and the direction of the screw insertion, which greatly improved the safety of the operation. In addition, the application of pre‐operative computer‐assisted virtual surgery technique could make it easy for the surgeon to find the marker of reduction, which improved the efficiency of operation. Although, Zhang et al. published data that the pelvic ring was asymmetrical, yet the difference in number was small. ³⁴ Hence, the mirrored acetabulum could be selected as a template for reduction.

Strengths and Limitations

Our study confirmed the feasibility of that the computer‐assisted virtual surgery technique could be used to evaluate if the involved PW in BACF should be managed through the posterior approach. Limitations of our study are the retrospective nature of the register study and the rather small number of cases. In addition, this study was only focused on the BCAF‐PW. It is also a question whether this method can be used to determine whether the PW should be managed or not in other acetabular anterior fractures combined with PW fractures, further studies are needed.

Conclusion

Our results show that three groups have similar quality of reduction and functional outcomes whether or not the posterior approach is performed to manage the involved PW. Additional approaches will increase blood loss and operative time. Hence, the application of this method to the operative plan is valuable, reliable and reproducible before operation.

Author Contributions

Xiaodong Guo and Yizhou Wan designed the study. Dong Yan and Keda Yu performed the data collection and analysis. Kaifang Chen helped perform the analysis with constructive discussions. Peiran Xue and Guixiong Huang completed the evaluation of postoperative reduction quality and hip function. All authors read and approved the final manuscript and consented to publish this manuscript.

Funding Information

This work was financially supported by the National Natural Science Foundation of China (grant Nos. 82272460 and 82072446).

Conflict of Interest Statement

All authors declared that there are no competing interests.

Ethics Approval and Consent to Participate

All participants in this study were informed and written informed consent was obtained. All experimental protocols were approved by the Ethics Committee of the Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, and consistent with the 1964 Helsinki declaration and its later amendments.

Data Availability Statement

All data generated and/or analyzed during this study are available from the corresponding author by reasonable request.