Current concepts: managing acetabular fractures in the elderly population

The infraacetabular screw versus the antegrade posterior column screw in acetabulum fractures with posterior column involvement: a biomechanical comparison

INTRODUCTION

Traditionally, plate osteosynthesis of the anterior column combined with an antegrade posterior column screw is used for fixation of anterior column plus posterior hemitransverse (ACPHT) acetabulum fractures. Replacing the posterior column screw with an infraacetabular screw could improve the straightforwardness of acetabulum surgery, as it can be inserted using less invasive approaches, such as the AIP/Stoppa approach, which is a well-established standard approach. However, the biomechanical stability of a plate osteosynthesis combined with an infraacetabular screw instead of an antegrade posterior column screw is unknown.

MATERIAL AND METHODS

Two osteosynthesis constructs were compared in a synthetic hemipelvis model with an ACPHT fracture: Suprapectineal plate + antegrade posterior column screw (APCS group) vs. suprapectineal plate + infraacetabular screw (IAS group). A single-leg stance test protocol with an additional passive muscle force and a cyclic loading of 32,000 cycles with a maximum effective load of 2400 N was applied. Interfragmentary motion and rotation of the three main fracture lines were measured.

RESULTS

At the posterior hemitransverse fracture line, interfragmentary motion perpendicular to the fracture line (p < 0.001) and shear motion (p < 0.001) and at the high anterior column fracture line, interfragmentary motion longitudinal to the fracture line (p = 0.017) were significantly higher in the IAS group than in the APCS group. On the other hand, interfragmentary motion perpendicular (p = 0.004), longitudinal (p < 0.001) and horizontal to the fracture line (p = 0.004) and shear motion (p < 0.001) were significantly increased at the low anterior column fracture line in the APCS group compared to the IAS group.

CONCLUSIONS

Replacing the antegrade posterior column screw with an infraacetabular screw is not recommendable as it results in an increased interfragmentary motion, especially at the posterior hemitransverse component of an ACPHT fracture.

Uncemented hip revision cup as an alternative for T-type acetabular fractures: A cadaveric study

BACKGROUND

The current rise in elderly patients with compromised bone quality complicates the surgical treatment of acetabular T-type fractures (AO type 62B2 fractures). There is on ongoing discussion about the treatment options, mostly consisting of an open reduction and internal fixation (ORIF) with or without primary or secondary total hip arthroplasty (THA). Yet, these patients are oftentimes unable to fulfil weight-bearing restrictions and mostly present with an unavailability of a stable anchor site. Consequently, this study investigates the feasibility of a cementless hip revision cup for acetabular T-type fractures and compares its biomechanical properties to ORIF.

HYPOTHESIS

The cementless hip revision cup provides sufficient biomechanical stability under the simulation of full weight-bearing.

PATIENTS AND METHODS

The study compared two groups of human cadaveric hip bones with T-type fractures, of whom 6 subjects were treated with ORIF (6 male; mean age: 62±17years; mean body weight: 75±15) versus 6 subjects treated with a cementless hip revision cup (2 male; 69±12 years; 73±15kg). The group-assignment was controlled for comparable BMD results (mean BMD: ORIF 110±37 mg Ca-Ha/mL versus hip revision cup 134±32 mg Ca-Ha/mL). To compare for biomechanical stability cyclic loading was applied measuring the force and dislocation of the fracture gap at standardized bone loci using an all-electric testing machine and a 3D-ultrasound measuring system.

RESULTS

Comparing superior pubic ramus versus iliac wing (cementless hip revision cup versus ORIF [mean±standard deviation]: 5.8±2.0 versus 7.0±3.2; p=0.032) as well as sacral ala versus iliac wing (4.6±2.2 versus 6.4±3.7; p=0.002), the cementless revision cup achieved a significantly higher stability than the plate osteosynthesis.

CONCLUSION

Revision cup and ORIF withstood biomechanical loading forces exceeding full weight-bearing in this biomechanical study. The results of our study suggest that the cementless hip revision cup might be promising alternative to the current standard care of ORIF with or without primary THA.

LEVEL OF EVIDENCE

III; case control experimental study.

The Association between Hip Joint Morphology and Posterior Wall Fracture: Analysis of Radiologic Parameters in Computed Tomography

Although numerous radiologic parameters of abnormal hip joint morphology are utilized in practice, studies on the relation of these parameters to acetabular fractures are limited. This study hypothesized that certain morphological features of hip joints are associated with acetabular posterior wall (PW) fracture patterns and aimed to identify morphological characteristics predictive of acetabular PW fracture. The records of 107 consecutive patients, who were diagnosed with acetabular fractures in a level I trauma center from August 2017 to April 2021, were initially reviewed. After excluding patients who lacked proper radiographic evaluation and had previous surgery or concomitant injury on the ipsilateral lower limb, a total of 99 patients were analyzed to investigate the morphological characteristics of the hip joint, measured in computed tomography, associated with acetabular posterior wall fracture. We included patient demographics, acetabular index (AI), sharp angle, acetabular depth-to-width ratio (AD/WR), center-edge angle (CEA), head-neck offset ratio (HNOR), acetabular head index (AHI), anterior acetabular sector angle (AASA), posterior acetabular sector angle (PASA), and acetabular version angle (AVA) in the univariate and multivariate analyses. The injury mechanism (p = 0.001) and AD/WR (p = 0.021) were predictors of PW fracture in the univariate analysis. In the multivariable analysis, injury mechanism (p = 0.011), AI (coefficient B = 0.320; Exp (B) = 1.377; p = 0.017), and AD/WR (coefficient B = 33.047; Exp (B) = 2.250 × 1014; p = 0.028) were significant predictors of PW fracture. This study highlights the importance of morphological factors, such as a larger AI and AD/WR, that may influence joint stress distribution, resulting in acetabular PW fracture. Understanding these pathomechanisms may protect the hip joint and prevent future injuries through the early identification and treatment of pathological conditions.

Higher Rates of Readmission After Acute Total Hip Arthroplasty Versus Open Reduction Internal Fixation for Elderly Acetabular Fractures, a National Study From 2010 to 2019

OBJECTIVES

To evaluate the initial complications and short-term readmissions and reoperations after open reduction internal fixation (ORIF) versus acute total hip arthroplasty (THA) for elderly acetabular fractures.

DESIGN

Retrospective database review.

SETTING

All hospitalizations in the National Readmissions Database and National Inpatient Sample.

PATIENTS/PARTICIPANTS

Patients 60 years of age or older with closed acetabular fractures managed surgically identified from the National Readmissions Database or National Inpatient Sample between 2010 and 2019.

INTERVENTION

Acute THA with or without ORIF.

MAIN OUTCOME MEASUREMENTS

30-, 90-, and 180-day readmissions and reoperations and index hospitalization complications.

RESULTS

An estimated 12,538 surgically managed acetabular fractures in elderly patients occurred nationally between 2010 and 2019, with 10,008 (79.8%) undergoing ORIF and 2529 (20.2%) undergoing THA. Length of stay was 1.7 days shorter ( P < 0.001) and probability of nonhome discharge was reduced (OR 0.68, P = 0.009) for THA patients than for ORIF patients. THA was associated with lower rates of pneumonia (4.6 vs. 9.1%, P < 0.001) and other respiratory complications (10.2 vs. 17.6%) when compared with ORIF. At 30 days, THA patients had higher rates of readmission (13.9 vs. 10.1%, P = 0.007), related readmission (5.4 vs. 1.2%, P < 0.001), readmission for dislocation (3.1 vs. 0.3%, P < 0.001), and reoperations (2.9 vs. 0.9%, P = 0.002). At 180 days, THA patients had higher rates of related readmission (10.1% vs. 3.9%, P < 0.001), readmission for dislocation (5.1% vs. 1.3%, P < 0.001), and readmission for SSI (3.4 vs. 0.8%, P = 0.005).

CONCLUSIONS

Acute THA is associated with lower length of stay and certain index hospitalization complications, but higher rates of readmissions for related reasons and specifically for dislocation.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Severe intraoperative vascular bleeding as main complication of acetabular fractures treated with plate osteosynthesis via the modified Stoppa approach

Acetabular fractures are challenging fractures and finding the best supportive treatment is complex. Many operative treatment options exist - one of them is the plate osteosynthesis via the modified Stoppa approach gaining popularity over the last decades. The purpose of this study is to give an overview of this surgical techniques and its main complications. Patients ≥ 18 years between the years 2016 and 2022 with acetabular fractures in our department received a surgical intervention with plate fixation via the modified Stoppa approach. All protocols and documents during a patient's hospital stay were analyzed to find relevant perioperative complications concerning this operative technique. Between 01/2016 und 12/2022 75 patients with acetabular fractures were treated surgically in the author's institution with a plate osteosynthesis via the modified Stoppa approach. In 26.7 % (n = 20) of all cases, patients were confronted with one or more perioperative complications typical for this operation. Intraoperative venous bleedings were the main complication with 10.6 % (n = 8). Postoperative functional impairment of the obturator nerve and deep vein thrombosis occurred with 2.7 % (n = 2) and 9.3 % (n = 7). This retrospective study shows that plate fixation via the Stoppa approach is a good treatment option because of the excellent intraoperative overview of the fracture, but has its pitfalls and complications. Especially severe vascular bleedings must be taken into account and its management well known.

[Primary joint replacement for the treatment of acetabular fractures]

Open reduction and internal fixation are the gold standard for the treatment of dislocated acetabular fractures. A primary joint replacement is only justified in isolated cases. The indications are merely non-reconstructable acetabular fractures, accompanying displaced fractures of the femoral neck and non-reconstructable fractures of the femoral head.Because of the difficulties in achieving sufficient cup stability, joint replacement for the treatment of acetabular fractures regularly requires implants designed for revision arthroplasty. The Kocher-Langenbeck approach provides the most versatile options, as it enables simultaneous stabilization of the dorsal acetabular structures, which are essential for the stability of the cup.For primary joint replacement as a treatment of acetabular fractures, survival of the prosthetic cup is markedly worse when compared to elective primary joint replacement. Particularly in younger patients but also in aged patients, every effort should be made to achieve a press fit of the cup. In most cases, this will include reduction and fixation of the fracture for stabilization of the acetabulum prior to joint replacement. A staged approach with an early secondary replacement intervention seems to provide better overall results than simultaneous fracture fixation and joint replacement.

Fracture lines and comminution zones in acetabular fractures based on three dimensional computed tomography

PURPOSE

To characterize the fracture patterns of acetabular fractures and create fracture maps and comminution zones based on three-dimensional (3D) computed tomography (CT) images.

METHODS

Sixty-eight computed tomography images of 67 patients (47 male [70.1%] and 20 female [29.9%], mean age: 45.2 ± 17.2 [range, 18-85 years] with the diagnosis of intra-articular acetabulum fracture were analyzed. Individual fracture lines were drawn and superimposed to a healthy acetabular template according to Judet-Letournel and simplified fracture classification systems. Fracture line, comminution zone, and heat maps were created using the computed tomography mapping technique.

RESULTS

Fracture lines were distributed mainly in a horizontal and oblique orientation, which concentrated in the anteroinferior part of the joint in anterior fractures. Posterior fractures mostly had an oblique orientation, which lied between the acetabular dome and middle part of the posterior wall. In complex fractures, fracture lines were concentrated just above the cotyloid fossa, acetabular dome, and posterosuperior part of the acetabulum. The most common comminuted zones were around the central area of the articular surface and the anterior wall in anterior fractures, between the cotyloid fossa and dome in complex fractures, and the upper half posterior wall.

CONCLUSION

Fracture patterns and comminution zones of acetabular fractures displayed certain characteristics. Some areas had higher comminution zones, and some areas remained intact in repeatable fracture patterns. These results may help surgeons in fixing acetabular fractures, designing new implants, and placement of acetabular component while performing THA after acetabular fractures.

Acetabular fractures treatment needs in the elderly and nonagenarians

Different treatment options for acetabular fractures in the elderly and nonagenarians exist; a consistent guideline has not been established, yet. The purpose of this study is to give an overview of how those fractures can be handled and compares two different surgical treatment methods. A total of 89 patients ≥ 18 years between 2016 and 2021 with acetabular fractures in our department received a surgical intervention with plate fixation via the Stoppa approach or a total hip arthroplasty with a Burch-Schneider ring and integrated cup. 60 patients ≥ 65 were compared in two groups, 29 patients between 65 and 79 and 31 patients ≥ 80. For comparison, data on operation times, hospitalization, complications during operation and hospital stay, blood loss and postoperative mobilization were collected. Characteristics could be found for indications for operative osteosynthesis or endoprosthetics based on the X-ray analysis. There was a tendency to treat simple fractures with osteosynthesis. Patients between 65 and 79 with an osteosynthesis had benefits in almost every comparison. Patients ≥ 80 with a plate fixation had advantages in the categories of postoperative complications, blood loss and transfusion of erythrocyte concentrates. Statistical significant differences were noticed in both groups regarding the operation time. Patients between 65 and 79 with osteosynthesis had significant benefits for postoperative complications, hospitalization, number of blood transfusions and postoperative mobilization. Finding the best supportive treatment option is difficult, and decision-making must respect fracture patterns and individual risk factors. This study shows that plate fixation via the Stoppa approach has some benefits.

Biomechanical analysis of fixation methods in acetabular fractures: a systematic review of test setups

Purpose

Optimal anatomical reduction and stable fixation of acetabular fractures are important in avoiding secondary dislocation and osteoarthritis. Biomechanical studies of treatment options of acetabular fractures aim to evaluate the biomechanical properties of different fixation methods. As the setup of the biomechanical test can influence the experimental results, this review aimed to analyze the characteristics, comparability and clinical implications of studies on biomechanical test setups and finite element analyses in the fixation of acetabular fractures.

Methods

A systematic literature research was conducted according to the PRISMA guidelines, using the PubMed/MEDLINE and Web of Science databases. 44 studies conducting biomechanical analyses of fixation of acetabular fractures were identified, which met the predefined inclusion and exclusion criteria and which were published in English between 2000 and April 16, 2021. The studies were analyzed with respect to distinct parameters, including fracture type, material of pelvis model, investigated fixation construct, loading direction, loading protocol, maximum loading force, outcome parameter and measurement method.

Results

In summary, there was no standardized test setup within the studies on fixation constructs for acetabular fractures. It is therefore difficult to compare the studies directly, as they employ a variety of different test parameters. Furthermore, the clinical implications of the biomechanical studies should be scrutinized, since several test parameters were not based on observations of the human physiology.

Conclusion

The limited comparability and restricted clinical implications should be kept in mind when interpreting the results of biomechanical studies and when designing test setups to evaluate fixation methods for acetabular fractures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-022-01936-9.