Update on post-traumatic periprosthetic acetabular fractures.

Aims: Post-traumatic periprosthetic acetabular fractures are rare but serious. Few studies carried out on small cohorts have reported them in the literature. The aim of this work is to describe the specific characteristics of post-traumatic periprosthetic acetabular fractures, and the outcome of their surgical treatment in terms of function and complications. Methods: Patients with this type of fracture were identified retrospectively over a period of six years (January 2016 to December 2021). The following data were collected: demographic characteristics, date of insertion of the prosthesis, details of the intervention, date of the trauma, characteristics of the fracture, and type of treatment. Functional results were assessed with the Harris Hip Score (HHS). Data concerning complications of treatment were collected. Results: Our series included 20 patients, with a mean age of 77 years (46 to 90). All the patients had at least one comorbid condition. Radiographs showed that 75% of the fractures were pure transverse fractures, and a transverse component was present in 90% of patients. All our patients underwent surgical treatment: open reduction and internal fixation, revision of the acetabular component, or both. Mean follow-up was 24 months, and HHS at last follow-up was 75.5 (42 to 95). The principal complications observed were dislocations of the prosthesis (30%) and infections (20%). A need for revision surgery was noted in 30% of patients. No dislocation occurred in patients undergoing osteosynthesis with acetabular reconstruction. We did not note either mechanical loosening of the acetabular component nor thromboembolic complications. In all, 30% of patients presented acute anemia requiring transfusion, and one death was reported. Conclusion: Post-traumatic periprosthetic acetabular fractures frequently have a transverse component that can destabilize the acetabular implant. The frequency of complications, principally dislocations, led to a high rate of revision surgery. Improvements in preoperative planning should make it possible to codify management to reduce this high rate of complications. The best results were obtained when the surgical strategy combined osteosynthesis with acetabular reconstruction.

The Saint-Joseph Acetabular score: a reproducible and accurate prediction of the outcome of open reduction and internal fixation of acetabular fractures.

PURPOSE: Acetabular fractures are associated to an increased risk of subsequent hip osteoarthritis. The only available score for post-operative reduction assessment in acetabular fractures (Matta's score) is x-ray based. CT-scan was shown superior to X-rays in post-operative reduction assessment. We aim to describe a CT-scan-based post-operative reduction score in acetabular fractures and evaluate its accuracy and reproducibility. METHODS: This is a retrospective study that includes 138 patients who underwent surgery for an acetabular fracture in our tertiary referral centre with a mean follow-up of 104.39±42.2 months. The post-operative CT-scan was reviewed and residual displacement (maximum gap and step) measured by three independent observers. The association between the occurrence of THA and the CT-scan measurements was evaluated. This led to a new prognostic score. The interobserver reliability and accuracy of this score were calculated. RESULTS: Interobserver reproducibility for the residual maximal gap was 0.82 (95% CI [0.70-0.89]) and 0.61 (95% CI [0.52-0.70]) for the residual maximal step displacement measurements. We created a score from a logistic regression model, attributing 1 point for every 1 mm of residual maximal step displacement and 1 point for every 2 mm of residual maximal gap displacement. The interobserver reproducibility of this score was 0.78 (95% CI [0.71-0.84]), and its AUC was 0.79 (95% CI [0.69-0.88]). CONCLUSION: This is the first CT-scan-based score for the assessment of residual displacement of a surgically treated acetabular fracture. It shows good interobserver reproducibility and accuracy in predicting the risk for secondary THA. It should be regularly used per-operatively (if per-operative 3D imaging is available) and post-operatively to predict the prognosis.

Minimally invasive removal of intra-articular hip fragments under navigation guidance.

The interposition of foreign bodies between the femoral head and the acetabulum represents a danger to the articular cartilage with a definite progression to osteoarthritis. Their removal is necessary and usually involves two surgical techniques: by open arthrotomy or under arthroscopy. The present article proposes a new surgical technique allowing the removal of intra-articular foreign bodies from the hip by a minimally invasive approach and aCT-guided navigation system. This technique is a good alternative that overcomes some shortcomings of other minimally invasive techniques, which struggle to access the fragment. It can also avoid specific complications of these procedures, such as the risk of abdominal compartment syndrome with arthroscopy, in the case of an associated acetabulum fracture.

Identification and treatment of atypical acetabular fractures having an independent acetabular roof fragment: Three-column fractures.

INTRODUCTION: A unique type of both-column fracture of the acetabulum that also has an independent roof fragment seems to occur relatively often. It is challenging to diagnose, thus our ability to detect it and its frequency are not known. This led us to analyze a database of acetabular fractures to 1) determine the incidence of this type of fracture, 2) describe its radiological characteristics, 3) attempt to set out a specific treatment strategy. HYPOTHESIS: The need for a dual surgical approach depends on the type and displacement of the independent roof fragment. METHODS: Four surgeons and radiologists independently analyzed a set of acetabular fractures that occurred between 2007 and 2017. The diagnosis was made using two-dimensional (2D) and three-dimensional (3D) CT reconstructions. Once the fractures had been identified, a detailed description was made of all 2D and 3D slices. A retrospective analysis was done of the reduction and fixation of the independent roof fragment relative to the chosen surgical approach. RESULTS: The study comprised 534 acetabular fractures, of which 96 where both-column fractures. In that subset, 41% (39 fractures) had an independent roof fragment. A detailed analysis resulted in the identification of two subtypes of three-column fracture with independent fragment: type 1 has a posterosuperior fragment (22 cases); type 2 has an independent fragment separated by a juxtatectal fracture line (17 cases). The best radiological outcomes were achieved when the independent fragment was minimally displaced and did not require additional reduction. CONCLUSION: The isolated roof fragment is common, as it occurs is more than one-third of both-column fractures. We were able to identify two subtypes that require different surgical strategies. Surgical treatment of these fractures is difficult; thus a combined surgical approach (anterior followed by posterior) may provide the best reduction, especially for subtype 1. LEVEL OF EVIDENCE: IV.

Clinical impact of intraoperative cone beam tomography and navigation for displaced acetabular fractures: a comparative study at medium-term follow-up.

INTRODUCTION: The use of per-operative cone beam tomography imaging for displaced acetabular fractures yields increased post-operative articular reduction accuracy. This study evaluates the need for total hip replacement (THR) and hip-related functional outcomes in patients with displaced acetabular fractures treated with O-ARM guidance compared to those treated under C-ARM guidance. MATERIALS AND METHODS: This is a prospective matched cohort study. Adult patients (35) with acetabular fractures operated under O-ARM guidance were included. These were matched (age, fracture type) to classically treated patients (35) from our data base. The primary outcome was the need for THR during three year follow-up period. Secondary outcomes were functional scores [Harris Hip score (HHS), Postel-Merle d'Aubigné (PMA)] and hip osteoarthritis grade at three year follow-up. Correlation between reduction gap and THR was evaluated. RESULTS: At three years, five patients were lost to follow-up in O-ARM group and four in control group. Two patients (6.66%) in the O-ARM group needed THR compared to eight patients in controls (25.80%) (p = 0.046). Hip X-ray osteoarthritis grade averaged 0.00 in patients without THR in O-ARM group compared to 0.22 in patients without THR in controls (p = 0.008). HHS averaged 95.79 in patients without THR in O-ARM group, compared to 93.82 in patients without THR in the control group (p = 0.41%). PMA averaged 17.25 in patients without THR in the O-ARM group compared to 17.04 in patients without THR in group 2 (p = 0.37). Evaluation of correlation between reduction gap and THR rate yielded OR = 1.22 (1.06-1.45). DISCUSSION: Increased accuracy in articular reduction, with per-operative three-dimensional control of impaction, in acetabular fractures led to significantly less need for THR in patients treated under O-ARM. Patients in both groups are comparable for functional outcomes because those with the lowest scores were offered THR. Per-operative cone beam guidance and navigation use are recommended in tertiary referral centres for acetabular trauma.

Modified Stoppa Approach: Beyond Acetabular Fractures: A Report of 2 Cases.

CASES: We used the modified Stoppa approach in a 17-year-old man with a retained bullet in his acetabular fossa. The acetabular hole was used to irrigate the hip joint. We also used this approach in a 29-year-old woman with right hip pain and limping to remove an isolated tenosynovial giant cell tumor ("localized pigmented villonodular synovitis") in the acetabular fossa expanding through the acetabulum. DISCUSSION: We believe that this approach should become more familiar because it offers a simple alternative for treating acetabular pathologies mainly involving the acetabular fossa, sparing patients the hazards of capsulotomy, trochanteric osteotomy, dislocation, and traction and fluid pressure in hip arthroscopy.

Knee injuries concomitant to posterior acetabular fractures: an association to look for.

PURPOSE: Acetabular fractures are frequently associated with other skeletal injuries, particularly knee injuries. This study aims to evaluate the relationship between posterior acetabular fractures and knee injury, analyzing its patterns and association with other injuries. METHODS: This is a retrospective monocentric study in a tertiary referral centre. We reviewed the data (age, sex, type of fracture, and concomitant injury) of patients hospitalized for a posterior acetabular fracture. We recorded concomitant knee injury diagnosed up to one year following acetabular fracture. RESULTS: Two-hundred-seventeen patients (177 males/40 females) were included. The mean age was 40.5 years. Eighty-five patients (39%) had a concomitant hip dislocation, nine (4.1%) had sciatic nerve palsy, 17 (7.8%) had upper extremity injury, and 18 (8.3%) had lower extremity injury (other than the knee). Eight (3.7%) patients had spine injury, 11 (5.1%) had severe thoracic injury, nine (4.1%) had an abdominal injury, and four (1.8%) had a head injury. There were 33 (15.21%, 95% CI 10.80-20.8%) patients (30 M/3 F) (group 1) with a concomitant knee injury and 184 patients without a concomitant knee injury(group 2). The mean age in group 1 was 34.3 compared to 45.4 in group 2(p = 0.021). The pattern analysis revealed five fractures, 14 ligamentous injuries (PCL injuries = 68%), and 14 soft tissue injuries. Sixteen (48.48%) injuries were identified during hospitalization and 17 (51.51%) during follow-up. There were an association between knee injury and upper extremity injury (OR = 3.49 95% CI 1.12-10.00,p = 0.022) and other lower extremity injury (OR = 3.18 95% CI 1.03-8.95,p = 0.032). DISCUSSION: Knee injury is the second most frequent lesion associated with posterior acetabular fractures. Being missed in half of cases, we recommend a systematic examination of ipsilateral knees under general anaesthesia, keeping a high index of suspicion and a low threshold for complementary knee imaging. Knee injury should be mainly looked for in patients younger than 60 years and in those with upper and/or lower extremities injuries.

Iliosacral screwing under navigation control: Technical note.

Percutaneous iliosacral screw fixation is an essential osteosynthesis technique for pelvic fractures and requires precise imaging tools to assist correct screw placement. 3D imaging coupled to navigation has significantly improved this technique. Several possibilities exist, depending on the instrument set used, with varying degrees of difficulty and very variable risk of error. The techniques traditionally described use a guide to navigate a drill bit, where a one-degree difference in trajectory can alter screw tip placement by several millimeters. The present article proposes a standardization of the procedure by using navigated pedicular screw instruments that have the advantage of navigating the instrument itself and not a projection. In a series of 90 screws implanted in 62 patients using this technique, only one path had to be repeated in the light of intraoperative control. No improperly positioned screws were found on postoperative control.

Anterior approach to the sacroiliac joint for pelvic ring fractures: Technical note.

Displaced pelvic fractures, combining an anterior lesion and sacroiliac disruption, most often require multiple surgical approaches. The technique we describe here allows these lesions to be treated by a single approach. It combines a Stoppa approach to address the anterior lesion and a pararectus approach to the sacroiliac joint through the same incision under the rectus abdominis muscle. This pararectus approach is done by passing laterally to the external and common iliac vessels. The entire anterior surface of the sacroiliac joint is exposed by the same passage through the abdominal wall. No neurological or vascular complications occurred in a 7-patient case series. Reduction was achieved in all cases. This approach is an interesting alternative to traditional approaches and enriches the surgeon's therapeutic arsenal for managing these complex fractures.

Epidemiology of pelvic and acetabular fractures in France.

INTRODUCTION: Acetabular and pelvic fracture accounts for 1.5% of fractures in adults and 2-5% of fractures requiring hospital admission. Several national-level epidemiological studies have been conducted outside France, but French national data are not known. We therefore assessed all patients admitted for acetabular or pelvic fracture in France between 2006 and 2016. The study objectives were: 1) to determine incidence of acetabular and pelvic fracture, 2) to determine progression in incidence between 2006 and 2016, and 3) to determine progression in treatment. HYPOTHESIS: Incidence of acetabular and pelvic fracture in France is increasing. METHODS: The following data for the period 2006-2016 were collated from the French national health insurance (CPAM: Caisse Primaire d'Assurance Maladie) database: gender, age, type of treatment, and geographical distribution by administrative area (Département). Two-tailed Student tests were used for comparison of means for numerical variables between independent samples; linear regression was used to analyze correlations; and the Chi2 test was used to compare percentages of categoric variables. RESULTS: There were 32,614 acetabular and 164,694 pelvic fractures, with male predominance for the acetabulum and female predominance for the pelvis. Mean age at acetabular fracture was 66±22 years (range, 1-108 years), and 74±20 years (range, 1-112 years) for pelvic fracture. The rate of acetabular fracture increased to 3,301 in 2016 from 2,316 in 2006, with a strong increase in the rate of pelvic fracture, to 18,902 in 2016 from 10,806 in 2006. Incidence of acetabular fracture per 100,000 increased from 3.67 in 2006 to 4.95 in 2016, and from 17.06 to 23.18 in over-75 year-olds. Incidence of pelvic fracture per 100,000 increased from 17.1 to 28.33, and from 129.30 to 210.69 in over-75 year-olds. Linear regression predicts incidence per 100,000 of 5.9 for acetabular fracture and of 41 for pelvic fracture by 2030 in young subjects and 32 and 309 respectively in over-75 year-olds. Management was surgical for acetabular fracture in 12.31% of cases in 2006 and in 14.33% in 2016, and in 1.43% and 2.16% respectively for pelvic fracture. DISCUSSION: The present data agree with previous reports, with strong increase in incidence of fracture in young and especially in elderly subjects. In elderly subjects, such fractures may require surgery. LEVEL OF EVIDENCE: IV, retrospective study without control group.

Intraoperative Cone Beam Tomography and Navigation for Displaced Acetabular Fractures: A Comparative Study.

OBJECTIVES: To evaluate the accuracy of reduction of the acetabular articular surface using an intraoperative computed tomography scanner (O-Arm) and screw navigation compared with a classical open technique. DESIGN: Prospective matched cohort study. SETTING: Tertiary referral center. PATIENTS/PARTICIPANTS: Adult patients with acute acetabular fractures were included in the study. All patients were treated by 2 senior surgeons using intraoperative imaging and screw navigation. MAIN OUTCOME MEASUREMENTS: The primary outcome measure was articular reduction. Secondary outcomes were radiation dosage, operative variables [operative time, time for image acquisition, intraoperative bleeding (cell saver), number of surgical plates, and number of screws], and postoperative variables (first postoperative day pain on the visual analog scale, postoperative transfusion, and hemoglobin change). P < 0.05 was considered statistically significant. RESULTS: Thirty-five patients were treated in the inclusion period (2016-2017) and were matched to 35 cases in our database (2013-2016). Mean age was 43 years, and the most common fracture type was a both-column fracture (OTA/AO type C). Postoperative image analysis showed that reduction was achieved in 87.1% of the cases in the O-Arm group versus 64.7% in the control group (P < 0.05). Mean gap of the articular fragments was 3.6 mm in the O-Arm group compared with 5.6 mm (P = 0.01) in the control group. There was no significant difference between the 2 groups in regards to all other studied variables except a decrease in intraoperative blood loss and transfusions and an increase in surgical time with the O-Arm group. Finally, the total radiation dose was decreased using the intraoperative O-Arm compared with a routine postoperative computed tomography scan (dose length product in O-Arm: 498 mGy.cm; dose length product in historical group: 715 mGy.cm). CONCLUSIONS: Using intraoperative imaging and screw navigation for displaced acetabular fractures allow screw navigation with increasing articular surface reduction accuracy. Operative and anesthesia times were not increased, whereas radiation exposure to the patient was significantly decreased. We recommend the use of intraoperative imaging for the treatment of displaced acetabular fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A New, Easy, Fast, and Reliable Method to Correctly Classify Acetabular Fractures According to the Letournel System.

BACKGROUND: Accurate classification of acetabular fractures remains difficult. To aid in the classification of acetabular fractures and to aid in teaching, our department developed a diagnostic algorithm that involves the use of 1 standardized 3-dimensional reconstruction of a computed tomography (CT) scan (an exopelvic view without the femoral head) with 8 anatomical landmarks. The algorithm was integrated into a smartphone application (app). The main objective of this study was to test the efficacy of this algorithm and smartphone app. METHODS: Fourteen reviewers (3 experts, 3 fellows, 3 residents, and 5 novice reviewers) evaluated a set of 35 CT scans of acetabular fractures in 2 phases. During the first phase, the scans (including axial 2-dimensional views and 3-dimensional (3D) multiplanar reconstruction views) were assessed by each reviewer twice, with an interval of 4 weeks between the readings to decrease recall bias. During that phase, the reviewers were provided with a diagram of the Letournel classification system with no guidelines for interpretation. During the second phase, performed 4 weeks after the first phase, 1 standardized 3D reconstruction (an exopelvic view without the femoral head) was reviewed twice, with an interval of 4 weeks between the readings. During that phase, the reviewers used the smartphone app. The primary outcome was the accuracy of classification. Interobserver reliability, reading time, and time needed for accurate classification were noted. RESULTS: The accuracy of fracture classification was 64.5% when the standard method of analysis was used and 83.4% when the app was used (p < 0.001). Improvement was noted in all groups, with the expert group showing the least improvement (88.6% to 97.2%, p = 0.04) and the novice group showing the most improvement (42.0% to 75.5%, p < 0.001). Furthermore, use of the app greatly increased the accuracy of classification of complex fractures. The average reading time was 71.8 minutes when the standard method was used and 37.4 minutes when the app was used. The interobserver reliability improved in all groups to an excellent reliability (interclass correlation coefficient [ICC] > 0.79). CONCLUSIONS: The Letournel classification system is difficult to understand and to learn but remains the only system guiding the surgical strategy for acetabular fractures. The impact of diagnostic algorithms is debatable. The most important finding of the present study is the high accuracy for inexperienced groups when the app was used. Another important finding is the high reliability of this method for the diagnosis of complex acetabular fractures.

Evaluation of venous thromboembolic complications in patients operated on for pelvic fracture.

INTRODUCTION: Fractures of the pelvis (acetabulum and pelvic ring) are complex in both radiological diagnosis and therapeutic management. They show high-risk of thrombosis, with variable rates of venous thromboembolic complications in the literature, ranging from 10% to 50%, with 0.5-10% risk of fatal pulmonary embolism. The objective of the present study was to determine the rate of venous thromboembolic events in a consecutive cohort of pelvic fracture and to attempt to identify thromboembolic risk factors in this population. MATERIAL AND METHOD: The study was based on a continuous retrospective series of 120 patients operated on between January 2015 and January 2017. Standard demographic data, clinical and diagnostic data for the fracture and the surgical approach were collected. Risk factors for venous thrombotic episodes were identified on Greenfield Risk Assessment Profile items (age, BMI, cancer, history of venous thromboembolism, surgery time, transfusion, femoral venous catheter, associated fracture) to define groups with high or low thrombotic risk. RESULTS: There was a 5% rate of venous thromboembolic events, and 2.5% of pulmonary embolism including 1 causing intraoperative death. The Greenfield score usually applied in surgery to assess venous thromboembolic risk did not seem relevant in this population already at high-risk of venous thromboembolism. No additional independent risk factors were identified. CONCLUSION: This is the largest cohort focusing on thromboembolic risk in pelvic fracture. The results refine rates reported in the literature. A prospective study, currently underway, should highlight risk factors so as better to prevent these complications.

Standardized three dimensional computerised tomography scanner reconstructions increase the accuracy of acetabular fracture classification.

PURPOSE: Evaluate the role of four standardized 3D reconstruction views in the accurate diagnosis of acetabular fractures. MATERIALS AND METHODS: Thirty-five acetabular fracture cases were selected from a tertiary centre database. Fourteen reviewers with different experience level evaluated this set of images which were provided in axial 2D views and multiplanar reconstruction (MPR) without 3D views in the first two readings then the standardized 3D views were added for the subsequent two readings. The primary outcome was the accuracy of diagnosis while inter-observer reliability and reading time as well as time needed for accurate diagnosis were evaluated. RESULTS: Accuracy of classification was 56.7% using the 2D and 73% using the described 3D (p < 0.001). Improvement was noted in all groups even though the expert group showed the least improvement (6.7% (p = 0.04)) and the least experience group showed the most improvement (35.7% (p < 0.001)). Average time of interpretation was 96 minutes for the 2D sets and 47 minutes for the 3D sets. Finally, the adding of the four standardized views increased the inter-observer reliability in all groups compared to the standard 2D sets with MPR. CONCLUSION: Acetabular fracture diagnosis according to Letournel classification is difficult and depends greatly on the experience of the reader. The described set of 3D images yields better accuracy and renders the diagnosis more repeatable and faster. We recommend the use of these images in classifying acetabular fractures.

[Orthopaedic surgery in the elderly]. / La chirurgie orthopédique chez le sujet âgé.

The specificities of elderly people in a surgical context determine their care. Orthopaedic surgery in these patients involves mainly fractures and prosthetic procedures.