Three-dimensional morphological analysis of quadrilateral plate fragments in associated both-column acetabular fractures

Comparative study of the 3D morphological differences in associated both-column acetabular fractures between elderly and young adults

INTRODUCTION

The occurrence of associated both-column acetabular fractures (ABC-AFs) is common in the elderly, yet their morphological characteristics compared to younger adults remain unclear.

MATERIALS AND METHODS

This retrospective study analyzed 123 cases of ABC-AFs: elderly patients (≥ 65 years, n = 47, group A) and younger adults (< 65 years, n = 76, group B). Using Mimics and 3-matic, fracture line (FL) distributions in the anterior column (AC), quadrilateral plate (QP), and posterior wall (PW) fragments were examined. Comparisons focused on the articular surface, ilium, QP area, and retro-acetabular surface (RAS). Harris hip scores (HHS) were recorded and compared one-year post-surgery.

RESULTS

The distribution of FLs of the AC fragment on the anteroinferior wall, acetabulum, inner and outer sides of the ilium was similar between groups A and B except that group A had sparser FL distribution on the posterosuperior rim and fewer FLs extending into the sacroiliac joint. A comparable pattern of FLs of the QP fragments on the QP area and the RAS was also confirmed. On the RAS, group A exhibited fewer cranial transverse lines (8.5% vs. 25.0%) and more inverse lines (44.7% vs. 23.7%) than group B (p = 0.011). A higher incidence of PW fragments was identified in group A (72.3% vs. 53.9%, p = 0.042). The number of intra-articular fragments was higher in group A than group B (3.8 vs. 3.4, p = 0.031), but the composition of the articular surface was similar. The average HHS was 77.6 in group A and 83.0 in group B (p = 0.007), with excellent/good ratios of 59.5% and 74.7% (p < 0.001), respectively.

CONCLUSIONS

The similar morphological patterns of ABC-AFs and favorable functional outcomes suggest that surgical principles for younger patients could be applicable to elderly patients, with careful considerations for osteoporosis and co-morbidities.

Pathoanatomy of the anterior column-posterior hemitransverse acetabular fracture

PURPOSE

To define the pathoanatomy of the anterior column-posterior hemitransverse (ACPHT) subtype of acetabulum fractures and assess the morphologic variation therein.

METHODS

Retrospective cohort study including 50 patients age greater than 60 with an ACPHT acetabular fracture managed operatively over an 11-year period at an ACS Level 1 Trauma center. Cross-sectional CT images were reviewed for anterior column/wall comminution, anterior column fracture exit point, completeness of the anterior column and posterior column fractures, articular impaction and quadrilateral surface continuity with the posterior column.

RESULTS

Comminution of the anterior column/wall was seen in 60% of patients. The anterior column fracture line exit was variable and exited below the anterior inferior iliac spine (AIIS) in 36% of fractures, at the AIIS or between the iliac spines in 40%, and through the iliac crest in 24%. A complete fracture was present in 72% of anterior column fractures and 44% of posterior column fractures. Impaction of the acetabular joint surface was present in 84% of patients. Continuity of the quadrilateral surface with the posterior column was present in 60% of cases.

CONCLUSIONS

Significant variability exists within the ACPHT fracture pattern. Understanding the variability within the ACPHT subtype is critical for adequately analyzing these patterns and has implications in future biomechanical studies and implant design.

LEVEL OF EVIDENCE

Level IV.

Progress of fracture mapping technology based on CT three-dimensional reconstruction

Fracture Mapping is a new technology developed in recent years. This technology visually representing the morphology of fractures by overlaying fracture lines from multiple fracture models onto a standard model through three-dimensional reconstruction. Fracture mapping has been widely used in acetabular fracture, proximal humerus fractures, Pilon fracture, tibial plateau fractures, and so on. This technology provides a new research method for the diagnosis, classification, treatment selection, internal fixation design, and statistical analysis of common fracture sites. In addition, the fracture map can also provide a theoretical basis for the establishment of a biomechanical standardized fracture model. Herein, we reviewed various methods and the most advanced techniques for fracture mapping, and to discuss the issues existing in fracture mapping techniques, which will help in designing future studies that are closer to the ideal. Moreover, we outlined the fracture morphology features of fractures in various parts of the body, and discuss the implications of these fracture mapping studies for fracture treatment, thereby providing reference for research and clinical decision-making on bone and joint injuries to improve patient prognosis.

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.