Intra-articular fragment mapping in associated both-column acetabular fractures

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

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.

Morphological analysis of the posterior elements of associated both-column acetabular fractures

BACKGROUND

It is still in dispute as to whether a posterior approach is applied to reduce the posterior fractures of associated both-column acetabular fractures (ABC-AFs).

PURPOSE

To analyze the morphological changes in the posterior elements including the posterior column (PC) and/or associated posterior wall (PW) fragments to provide a reference for surgical planning.

MATERIAL AND METHODS

The 3D computed tomography (CT) data of 100 cases of ABC-AFs were retrospectively analyzed using Mimics and 3-Matic software. The line distribution of the retroacetabular surface (RAS), the acetabular fossa, and the size of the PW fragments were analyzed.

RESULTS

Fracture lines (n = 89) on RAS appeared in three patterns: transverse lines (n = 41) on the cephalic (65.8%) and caudal (29.3%) thirds; oblique lines (n = 34) on the mid-caudal thirds; and multifragmentary lines (n = 14). The lines of the displaced PW fragment (n = 61) were widely distributed in intra- and extra-articular regions. The mean radian of the PW fragments was >90° in 67.2% of cases and involved anteriorly to the vertex in 90.2% of cases. The average fracture span on the RAS was 0.60-1.00 in 63.9% of cases. The mean length of the spike of PW fragments was >20 mm in 80.3% of cases.

DISCUSSION

For PC fractures, transverse lines on the cephalic third of RAS indicated a possibility of the anterior approach, while transverse lines on the distal third or oblique and multifragmentary lines suggest the posterior approach. A displaced PW fragment was involved more extensively both intra-and extra-articularly and may be optimally treated via a posterior approach.