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.

The influence of bone quality on radiological outcome in 50 consecutive acetabular fractures treated with a pre-contoured anatomic suprapectineal plate.

PURPOSE: To investigate the range of indications of an anatomical-preshaped three-dimensional suprapectineal plate and to assess the impact of the bone mass density on radiologic outcomes in different types of acetabular fractures. PATIENTS AND METHODS: A consecutive case series of 50 acetabular fractures (patient age 69 ± 23 years) treated with suprapectineal anatomic plates were analyzed in a retrospective study. The analysis included: Mechanism of injury, fracture pattern, surgical approach, need for additional total hip arthroplasty, intra- or postoperative complications, as well as bone mass density and radiological outcome on postoperative computed tomography. RESULTS: Most frequently, anterior column fracture patterns with and without hemitransverse components as well as associated two column fractures were encountered. The anterior intrapelvic approach (AIP) was used in 98% (49/50) of the cases as primary approach with additional utilization of the first window of the ilioinguinal approach in 13/50 cases (26%). Determination of bone density revealed impaired bone quality in 70% (31/44). Postoperative steps and gaps were significantly greater in this subgroup (p < 0.05). Fracture reduction quality for postoperative steps revealed anatomic results in 92% if the bone quality was normal and in 46% if impaired (p < 0.05). In seven cases (14%), the plate was utilized in combination with acute primary arthroplasty. CONCLUSION: A preshaped suprapectineal plate provides good radiological outcomes in a variety of indications in a predominantly geriatric cohort. Impaired bone quality has a significantly higher risk of poor reduction results. In cases with extensive joint destruction, the combination with total hip arthroplasty was a valuable option.

Anterior intrapelvic approach and suprapectineal quadrilateral surface plate for acetabular fractures with anterior involvement: a retrospective study of 34 patients.

BACKGROUND: The purpose of the study is to evaluate the use of the suprapectineal quadrilateral surface (QLS) plates associated with the anterior intrapelvic approach (AIP) to the acetabulum in the surgical treatment of acetabular fractures with anterior involvement. METHODS: We did a retrospective study of patients surgically treated with QLS plates and AIP for acetabular fractures with the involvement of the anterior column, between February 2018 and February 2020, in our Hospital. The following data were recorded: mechanism of injury, the pattern of fracture, presence of other associated injuries, the time before performing the surgery, surgical approach, position on operating table, time of surgery, intraoperative bleeding, hospitalization time, intraoperative and postoperative complications. Follow-ups were performed at 1, 3, 6, 12 months, then annually. The clinical-functional outcome was assessed with the Merle d'Aubigne Postel score (MAP) modified by Matta; while the radiological outcome with the Matta Radiological Scoring System (MRSS). A Chi-square test was utilized to examine associations between parametric variables. RESULTS: We included 34 patients, mean age 62.1, with an average follow-up of 20.7 months. The most frequent traumatic mechanism was road trauma. There were 15 isolated anterior columns and 19 associated patterns. There were 5 cases of associated visceral injuries, and 10 cases of other associated skeletal fractures. All patients were in the supine position. The surgical approach used was the AIP in all cases, with the addition of the first window of the ilioinguinal approach in 16 cases and of the Kocher-Langenbeck approach in 2 cases. The average time before performing the surgery was 8.5 days. The mean time of the surgery and the mean length of stay after surgery were 227.9 min and 8.2 days, respectively. There weren't cases of intra-operative complications, while there were postoperative complications in 5 patients. The MRSS was judged anatomical in 26 cases, imperfect in 7 cases and poor in 1 case. The average MAP value was 15.2. We observed a significant relationship between the radiological outcome and the clinical outcome (p < 0.05). CONCLUSIONS: The QLS plates in association with the AIP approach represent an effective treatment strategy for the treatment of acetabular fractures with anterior involvement.

The Harrington plus reconstruction for pelvic and acetabular metastases.

BACKGROUND: Surgical management of periacetabular bone metastases is challenging. The Harrington Plus reconstruction is a modification of the original Harrington rod technique. An intrapelvic suprapectineal plate is used, with the aim of reconstructing a disrupted anterior column and reducing the risk of failure in cases where there is extensive medial bone loss. METHODS: A retrospective review of the 13 patients who have undergone the Harrington Plus procedure to date was performed. Mobility status, EQ5D and Oxford Hip scores were assessed. RESULTS: There was a significant improvement in mobility status, EQ5D and Oxford Hip Scores at 6 months postoperatively (p < 0.05). Two patients returned to theatre for debridement of infection. There were no postoperative dislocations, cup medialisation or cases of loosening of the prosthesis. No patient required revision arthroplasty surgery. CONCLUSION: The Harrington Plus procedure produces a reliable construct that allows patients with extensive periacetabular metastatic defects to fully weight-bear. Careful patient selection and multidisciplinary management is essential.

The use of suprapectineal plate in acetabular fractures via ilioinguinal approach with Stoppa window.

Objective: The aim of the study was to investigate the clinical results of open reduction and internal fixation using a suprapectineal buttress plate for specific acetabular fractures. Methods: We conducted a retrospective study involving thirty-three patients with specific acetabular fractures in an academic level 2 trauma center. We performed the ilioinguinal approach with Stoppa window for buttress plating of the quadrilateral surface. Clinical examination, radiographs and computed tomography were done using criteria described by Matta. Functional outcome was evaluated by visual analog scale (VAS), WOMAC, Harris Hip score modified, Hip disability and Osteoarthritis Outcome Score (HOOS) and modified Merle d'Aubignè scoring system. Results: Average follow-up was 40.4 months with a minimum of 24 months. Mean age was 59.09 years. The 82% of patients were treated with a suprapectineal plate using ilioinguinal approach with Stoppa window. The 18% of patients required a Kocher-Langenbeck approach in order to get anatomic reduction of posterior wall or column. The 91% of patients were satisfied of their condition during activity of day living and only a small cohort reported walking aids. The worst clinical results were obtained in patients characterized by highest step displacement. Deep infection of surgical wound was observed in 6% of patients. In 3% of patients, one vascular injury occurred during surgery. Conclusion: Internal fixation using ilioinguinal approach with Stoppa window and a suprapectineal plate to buttress the quadrilateral plate should be considered a viable treatment of some acetabular fractures. Patients can expect a good functional outcome with a low complication rate.

The Effect of Lateralization of a Pelvic Brim Plate on the Fixation of an Anterior Column Fracture: A Biomechanical Analysis.

Objectives Anterior column fractures can be seen as either isolated or accompanied by many types of complex acetabulum fractures. The aim of this study was to biomechanically compare the stability of a standard pelvic brim plate with a more laterally located suprapectineal plate, which is more commonly used in minimally invasive application, on an intermediate height anterior column fracture model under dynamic and static loading. Materials and methods Right side, adult, foam cortical shell artificial hemipelvis models were used (Sawbones, Pacific Research Laboratories, Vashon, WA, USA). Twenty-four (24) pieces of foam cortical shell artificial hemipelvis models were separated into three groups (M, L, and control). In group "M," a suprapectineal plate was placed medially just adjacent to the pelvic brim. In group "L," a laterally located suprapectineal plate was placed 2 cm lateral of the pelvic brim at its most proximal point. Then, dynamic load testing of 1000 cycles between 50 N and 500 N force and a static load test of 1.2 kN at 2 mm/minute were applied. Dynamic and static tests were conducted on an axial compression device. Displacements were measured after dynamic and static loading conditions. Results In the dynamic loading test at the AL point (superior intersection of the fracture line with the acetabular roof), the median displacement was significantly higher in group L than in group M (0.12 (IQR: 0.058-0.8125) mm and 0.04 (IQR: 0.03-0.065) mm (p = 0.02)). There was no other statistically significant difference in the displacement amounts in both dynamic and static loading conditions at other measurement points. The comparison of the stiffness of the M and L groups showed no statistically significant results, while the control group was significantly more rigid than both the M and L groups (p = 0.04 for both). None of the artificial hemipelvis models was found to be fractured at the end of the test. Conclusion Suprapectineal plates, placed on either the medial or lateral aspect of the pelvic brim, may be used for the fixation of anterior column-type fractures to provide rigid fixation and stability. As plate location did not impact stiffness and stability, the results suggest that surgeons have flexibility in determining the fixation based on accessibility, fracture pattern, and surgeon experience.

Biomechanical comparison of acetabular fracture fixation with stand-alone THA or in combination with plating.

PURPOSE: A common surgical treatment in anterior column acetabular fractures with preexisting osteoarthritis is THA, which is commonly combined with plate osteosynthesis. Implantation of a solitary revision cup cranially fixed to the os ilium is less common. The purpose of this study was to compare the stabilization of anterior column acetabular fractures fixed with a cranial socket revision cup with flange and iliac peg or with a suprapectineal plate osteosynthesis combined with an additional revision cup. METHODS: In 20 human hemipelves, an anterior column fracture was stabilized by either a cranial socket revision cup with integrated flange (CF = Cup with Flange) or by a suprapectineal plate combined with a revision cup (CP = Cup and Plate). Each specimen was loaded under a stepwise increasing dynamic load protocol. Initial construct stiffness, interfragmentary movements along the fracture line, as well as femoral head movement in relation to the acetabulum were analyzed. RESULTS: Both groups showed comparable initial construct stiffness (CP: 3180 ± 1162 N/mm and CF: 3754 ± 668 N/mm; p = 0.158). At an applied load of 1400 N, interfragmentary movements at the acetabular (p = 0.139) and the supraacetabular region (p = 0.051) revealed comparable displacement for both groups and remained below 1 mm. Femoral head movement in relation to the acetabulum also remained below 1 mm for both test groups (p = 0.260). CONCLUSION: From a biomechanical point of view, both surgical approaches showed comparable fracture reduction in terms of initial construct stiffness and interfragmentary movement. The potential benefit of the less-invasive cranial socket revision cup has to be further investigated in clinical studies.

The Advantages of Stoppa Approach-ilioinguinal Modification, for Surgical Treatment of the Acetabulum Fractures with the Traditional Plate and the New Anatomical Suprapectineal Plate System.

INTRODUCTION: Two similar pelvic fracture cases were both treated with the new anterior intrapelvic (AIP) approach (modified Stoppa approach)-the ilioinguinal modification. The traditional reconstruction plate is used in case 1 and the new special designed anatomical quadrilateral plate (the suprapectineal edition) is used in case 2. The two cases are discussed in terms of surgical difficulty, surgical time, blood loss, patient recovery, stability of the osteosynthesis. CASE REPORT: Two similar cases according to the classification of Judet-Letournel acetabulum fractures were chosen. Case 1 is a male 55 years old, injured in a motor vehicle accident who had a pelvic fracture, especially a quadrilateral surface fracture in conjunction with high anterior column fracture. Case 2 is also a male 58 years old, who fall from height, had almost the same fracture type according to Judet-Letournel classification. The traditional reconstruction plate was used in case1 and the new anatomical suprapectineal plate system was used for internal fixation in case 2. CONCLUSION: The application of the new suprapectineal plate system (anatomical plate) as seen in case 2 is not possible through the ilioinguinal approach only. The use of AIP is imperative for the fixation of the quadrilateral surface fracture using these anatomical plates. The combination of the AIP with the lateral window or the first two windows of ilioinguinal approach gives excellent access to the true pelvis and the ilium in the high anterior column fractures.

Biomechanical comparison of three different fixation techniques for anterior column posterior hemitransverse acetabular fractures using anterior intrapelvic approach.

OBJECTIVES: The aim of this study was to biomechanically compare three different fixation methods for the fixation of anterior column posterior hemitransverse type acetabular fracture (ACPHT). METHODS: ACPHT fracture models were created on twenty-four foam cortical shell artificial hemipelvis models. Three fixation methods were assessed - Group 1: posterior column lag screws over a suprapectineal plate; Group 2: Posterior column lag screws over a suprapectineal plate and an infrapectineal plate; Group 3: A suprapectineal plate and a vertical infrapectineal plate. Stiffness and displacement amounts of fixation methods under dynamic and static axial loading conditions were measured. RESULTS: In the dynamic and static tests, Group 3 showed the less stable fixation compared to Group 2. There was no statistically significant difference between the stiffness values of the fixation groups. In the static tests, there was no statistically significant difference between Group 1 and 2, although less displacements were obtained in Group 2. CONCLUSIONS: A combination of posterior lag screws over a suprapectineal plate and an infrapectineal plate supporting the pelvic brim along both sides of the linea terminalis resulted in a better fixation construct than a suprapectineal plate accompanying with a vertical infrapectineal plate provide better stability with less fracture displacement.