3D printing techniques have attracted a lot of curiosity in various surgical specialties and the applications of the 3D technology have been explored in many ways including fracture models for education, customized jigs, custom implants, prosthetics etc. Often the 3D printing technology remains underutilized in potential areas due to costs and technological expertise being the perceived barriers. We have applied 3D printing technology for acetabular fracture surgeries with in-house, surgeon made models of mirrored contralateral unaffected acetabulum based on the patients’ trauma CT Scans in 9 patients. The CT Scans are processed to the print with all free-ware modeling software and relatively inexpensive printer by the surgeon and the resulting model is used as a ‘reduced fracture template’ for pre-contouring the standard pelvic reconstruction plates. This allows use of the standard surgical implants, saves time on intra-operative plate contouring, and also aids in reduction to an extent. We share through this presentation the workflow of the freeware softwares to use in order to use this surgical planning and implant preparation that may remove the perceived barriers of cost and technology from surgeons that wish to explore using 3D printing technology for acetabular fracture management and may extend applications to other regions

Injury to the sciatic nerve is one of the more serious complications of acetabular fracture and traumatic dislocation of the hip, both in the short and long term. We have reviewed prospectively patients, treated in our unit, for acetabular fractures who had concomitant injury to the sciatic nerve, with the aim of predicting the functional outcome after these injuries. Of 136 patients who underwent stabilisation of acetabular fractures, there were 27 (19.9%) with neurological injury. At initial presentation, 13 patients had a complete foot-drop, ten had weakness of the foot and four had burning pain and altered sensation over the dorsum of the foot. Serial electromyography (EMG) studies were performed and the degree of functional recovery was monitored using the grading system of the Medical Research Council. In nine patients with a foot-drop, there was evidence of a proximal acetabular (sciatic) and a distal knee (neck of fibula) nerve lesion, the double-crush syndrome. At the final follow-up, clinical examination and EMG studies showed full recovery in five of the ten patients with initial muscle weakness, and complete resolution in all four patients with sensory symptoms (burning pain and hyperaesthesia). There was improvement of functional capacity (motor and sensory) in two patients who presented initially with complete foot-drop. In the remaining 11 with foot-drop at presentation, including all nine with the double-crush lesion, there was no improvement in function at a mean follow-up of 4.3 years

Total hip arthroplasty (THA) is frequently performed as a salvage procedure for the acetabular fracture when posttraumatic osteoarthritis, posttraumatic avascular necrosis, or fixation failure with subluxation develop. Special considerations for this situation include previous surgical exposure with dense scar tissue, the type and location of implants, the location and amount of heterotopic ossification, indolent infection, previous sciatic nerve palsy, and the pathoanatomy of existing acetabular defect. These factors can influence the choice of surgical exposure and the reconstructive method. The outcomes of THA after acetabular fracture are generally less favorable than those of the nontraumatic degenerative arthritis. Reason for this high failure is the low mean age and the high activity level of the patient. Other important reasons for failure include the problem of acetabular bone deficiency and compromised bone quality. We evaluated the results of cementless THA in patient who had previous acetabular fracture. We also compared this result with those of patients with posttraumatic avascular necrosis of the femoral head. Forty-five consecutive cementless THAs were performed for the treatment of post-traumatic osteoarthritis after acetabular fracture between December 1993 and December 2008. Of these patients, 15 patients were died or lost to follow-up monitoring before the end of the minimum one year follow-up period. This left 30 patients (30 hips) as the subjects of our retrospective review. We evaluated the clinical and radiographic results of these patients and compared with the results of THA in patients with post-traumatic AVN of the femoral head which had without acetabular damage. Two hips required revision of the cup secondary to early migration of the acetabular cup (1 hip) and postoperative deep infection (1 hip). There was no significant difference in clinical and radiographic results between two groups except implanted acetabular component size and required bone graft (p<0.05). The Kaplan-Meier ten-year survival rate, with revision as the end-point, was 90% and 96.7% with loosening of acetabular component as the end-point. Our series suggested that compared with cemented components, uncemented sockets may improve the results of arthroplasty after previous acetabular fracture. In conclusion, cementless THA following acetabular fracture presents unique challenge to the surgeon, careful preoperative assessment and secure component fixation with proper bone grafting is essential to minimize problems

Objective. To investigate the relationship between the pattern of pelvic or acetabular fracture, and bladder injuries. Methods. A total of 173 patients admitted at our Academic Hospital from January 2006 to March 2012 with cystograms done for pelvic or acetabular fractures were studied retrospectively. Records of pelvic X-Rays, CT scans and cystograms were reviewed. Tile's classification and Young & Burgess classification were used for pelvic fractures and Judet & Letournel classification system for acetabular fractures. Results. Out of 173 patients 16% had bladder injuries of which 22% were intra-peritoneal and 70% were extra-peritoneal. The bladder injuries mostly occurred among male patients; 16 males compared to 9 female patients. Out of the 21 fractures of the acetabulum only 2 sustained bladder injury and they were secondary to gunshot wounds. Lateral compression fractures accounted for 67% of bladder injuries. Motor vehicle accidents were the leading mechanism of injury accounting for 117 patients in total and 81% of those with bladder injuries. Among the patients with bladder rupture 55% had at least 3 rami involved and only one patient (4%) with 1 ramus involved had a bladder injury. Overall 44 (34%) of patients with 3 or more rami fractured had bladder injury. Conclusion. Bladder injury appears to be related to the mechanism of injury. We recommend that a cystogram be done routinely when a patient presents with a type III lateral compression fracture. In isolated acetabulum fractures, single ramus fractures and lateral compression type I fractures, request for cystogram should be correlated with clinical signs and symptoms, and not done routinely. NO DISCLOSURES

Background and Objective. Total hip arthroplasty (THA) has been applied to treat pain and disability in patients with post-traumatic arthritis after acetabular fracture for many years. However, the midterm and long-term results of THA for this unique population are still controversial. According to previous studies, we found that uncemented acetabular reconstructions were usually performed in patients who were most likely to have the best results and an abnormal acetabular structure was usually the reason for THA failure. In this study, we evaluated the midterm results of using uncement acetabular components to treat posttraumatic arthritis after acetabular fracture. In addition, we investigated the effects of different acetabular fracture treatments and fracture patterns on THA. Materials and Methods. Between January 2000 to December 2003, 34 uncemented acetabular reconstructions were performed in 34 patients for posttraumatic arthritis after acetabular fractures. Among them, 31 patients underwent complete clinical and radiographic follow-up for an average of 6.3 years (range, 3.1–8.4 years). There were 22 men and 9 women. The patients' average age was 51 ± 12 years (range, 27–74 years) at the time of arthroplasty. The average interval from fracture to THA was 5.58 ± 4.42 years (range, 0.75–17.5 years). Of the 31 patients, 19 had undergone ORIF (open-reduction group) and 12 had received conservative treatment for the acetabular fractures (conservative-treatment group). Then, 14 had simple pattern fractures (simple group) and 17 had complex pattern fractures (complex group). After midterm follow-up, the radiographic and clinic results of the different groups were compared. Results. During 6.3 years' follow up, no infection occurred and no revision was needed in the 31 patients. In the open-reduction and conservative-treatment groups, the respective averages for duration of surgery, intraoperative blood loss, and amount of blood transfused were 138 ± 29 minutes and 98 ± 16 minutes (P < .001), 726 ± 288 mL and 525 ± 101 mL (P = .01), and 1,130 ± 437 mL and 1,016 ± 422 mL (P = .62). In the complex group and the simple group, the respective averages for duration of surgery, intraoperative blood loss, and amount of blood transfused were 132 ± 28 minutes and 109 ± 31 minutes (P = .042), 741 ± 221 mL and 536 ± 248 mL (P = .02), and 1,100 ± 414 mL and 1,075 ± 456 mL (P = .91). The average Harris Hip Score increased from 49 ± 15 before surgery to 89 ± 5 in the latest follow up, and 29 patients (94%) had either excellent or good results. The average Harris Hip Score for the open-reduction group and the conservative-treatment group increased to 87 ± 6 and 91 ± 3 (P = .07), respectively, after surgery; for the complex group and the simple group, it increased to 88 ± 6 and 90 ± 4 (P = .25), respectively. There was no significant difference between the open-reduction group and the conservative-treatment group or between the complex group and the simple group regarding the number of hips with excellent and good results. Of our 31 patients, none had a change in acetabular component abduction of >4°. The average horizontal migration of cup was 1.48 ± 0.46 mm (range, 0.7–2.33 mm), and the average vertical migration was 1.41 ± 0.54 mm (range, 0.5–2.51 mm). The average rate of polyethylene liner wear was 0.25 ± 0.11 mm/y (range, 0.03–0.41 mm/y). Average wear rates were 0.25 ± 0.12 mm/y and 0.24 ± 0.11 mm/y for the open-reduction group and the conservative-treatment group (P = .72), respectively, and 0.24 ± 0.13 mm/y and 0.26 ± 0.10 mm/y in the complex group and the simple group (P = .67), respectively. The average rate of polyethylene wear for all patients was positively related to BMI (r = .36; P = .047). After THA, all 31 patients had a reconstructed hip center within 20 mm of vertical and horizontal symmetry compared with the contralateral hip, including 27 patients (87%) with anatomic restoration and 4 patients with reconstructed hip center between 10–20 mm of vertical and horizontal symmetry. Anatomic restoration was positively related to fracture treatment (r = .48; P = .006), but it had no relation to fracture pattern (r = .16; P = .40). Conclusion. Uncement acetabular reconstruction following acetabular fracture had favorable midterm results. Fracture treatments and patterns are associated with increased operative time and hemorrhage amount. Open reduction and internal fixation of fracture favours anatomic restoration of hip rotational center

Stable, anatomical fixation of acetabular fractures gives the best chance of a good outcome. We performed a biomechanical study to compare fracture stability and construct stiffness of three methods of fixation of posterior wall acetabular fractures. Two-dimensional motion analysis was used to measure fracture fragment displacement and the construct stiffness for each fixation method was calculated from the force / displacement data. Following 2 cyclic loading protocols of 6000 cycles, to a maximum 1.5kN, the mean fracture displacement was 0.154mm for the rim plate model, 0.326mm for the buttress plate and 0.254mm for the spring plate model. Mean maximum displacement was significantly less for the rim plate fixation than the buttress plate (p=0.015) and spring plate fixation (p=0.02). The rim plate was the stiffest construct 10962N/mm (SD 3351.8), followed by the spring plate model 5637N/mm (SD 832.6) and the buttress plate model 4882N/mm (SD 387.3). Where possible a rim plate with inter-fragmentary lag screws should be used for isolated posterior wall fracture fixation as this is the most stable and stiffest construct. However, when this method is not possible, spring plate fixation is a safe and superior alternative to a posterior buttress plate method

Background. Referral to centres with a pelvic service is standard practice for the management of displaced acetabular fractures. Hypothesis. The time to surgery: (1) is a predictor of radiological and functional outcome and (2) this varies with the fracture pattern. Methods. A retrospective case review of 254 patients over a ten year period with a minimum follow-up of two years. Patients were divided into two groups based on fracture pattern: elementary or associated. ‘Time to surgery’ was analysed as a continuous and a stratified variable. The primary outcome measures were the quality of reduction and functional outcome. Logistic regression analysis was used to test our hypothesis, while controlling for potential confounding variables. Results. For elementary fractures, an increase in the time to surgery on one day reduced the odds of an excellent/good functional result by 15% (p = 0.001) and of an anatomical reduction by 18% (p = 0.0001). For associated fractures, the odds of obtaining an excellent/good result were reduced by 19% (p = 0.0001) and an anatomical reduction by 18% (p = 0.0001) per day. When ‘time’ was measured as a categorical variable, an anatomical reduction was more likely if surgery was performed within 15 days (elementary) and five days (associated). An excellent/good functional outcome was more likely when surgery was performed within 15 days (elementary) and ten days (associated). Conclusion. The time to surgery is a significant predictor of radiological and functional outcome for both elementary and associated displaced acetabular fractures. The organisation of regional trauma systems must be capable of satisfying these time-critical targets to achieve optimal patient outcome

Certain acetabular fractures involve impaction of the weight-bearing dome and medialisation of the femoral head. Intra-operative fracture reduction is made easier by traction on the limb, ideally in line with the femoral neck (lateral traction). However, holding this lateral traction throughout surgery is very difficult for a tiring assistant. We detail a previously undescribed technique of providing intra-operative lateral femoral head traction via a pelvic reduction frame, to aid fixation of difficult acetabular fractures. The first 10 consecutive cases are reviewed (Group 1) and compared with a retrospective control (Group 2, n=18) of case-matched patients, treated prior to introducing the technique. The post-operative X-rays and CT scans were assessed to identify quality of fracture reduction according to the criteria of Tornetta and Matta. Operative time, blood loss and early complication rates were also compared. All cases in both groups were acute injuries with medial and/or superior migration of the femoral head. The majority were either associated both column or anterior column posterior hemi-transverse. There was no statistical difference between the groups in age, time to surgery, BMI or ASA grade. Fracture reduction was assessed as excellent in seven, good in three and poor in one. This was not significantly different from the control group (p=0.093). The mean operative time was 232 minutes in Group 1 and 332.78 minutes in Group 2 (p = 0.0015). There was no difference between the groups for blood loss or complication rates. We conclude that this new technique is at least equivalent to using manual traction and early results suggest it reduces operative time and technical difficulty in treating these complex acetabular fractures

It is widely recognised that pelvic disruption in association with high-energy trauma is a life-threatening injury. The potential morbidity and mortality associated with acetabular injuries are less well understood. Due to chronic underfunding and the absence of a comprehensive and coordinated national approach to the management of acetabular trauma throughout the UK, patients can incur prolonged recumbency. Prompt and appropriate referral for specialist management, thromboprophylaxis and venous thrombosis surveillance are important issues for the referring centre. We performed a postal questionnaire to establish the current clinical practice in the specialist centres throughout the UK in pelvic and acetabular trauma, with respect to time to surgery, thromboprophylaxis, and surveillance. We identified twenty-one units and thirty-seven surgeons in the NHS who deal with pelvic and acetabular injuries. The mean time to surgery from injury in the UK is 8.5 days (range 2-19 days). The larger units that accept and treat patients from outside their region experience the greatest delay to surgery. Mechanical thromboprophylaxis was used in 67% (14) of the units. 24% (5) use arterio-venous boots, 19% (4) use calf pumps, and 52% (11) use TEDS stockings. No unit routinely use prophylactic IVC filters in acetabular trauma. Chemical thromboprophylaxis is routinely used in 100% (21) of the units. 95% (20) used prophylactic doses of unfractionated heparin or low molecular weight heparin. Clinical surveillance alone for thromboembolism is employed in 90% (19) of the units. Only 2 (10%) units routinely perform radiological surveillance with ultrasound Doppler on its acetabular fracture cases pre-operatively. Currently there is no published directory of dedicated pelvic and acetabular surgeons in the UK. There is no general consensus on the approach to thromboprophylaxis and surveillance in acetabular trauma in the UK. There is no consensus approach to thromboprophylaxis and surveillance in the literature

Introduction. Acetabular fractures are a challenging problem. It has been published that outcome is dependent upon the type of fracture, the reduction of the fracture and concomitant injuries. The end-points of poor outcome include avascular necrosis of the femoral head, osteoarthritis. However, we lack definitive statistics and so counselling patients on prognosis could be improved. In order to achieve this, more outcome studies from tertiary referral centres are required. We present the first long term follow up from a large tertiary referral Centre in Ireland. Methods. We identified all patients who were ten years following open reduction and internal fixation of an acetbular fracture in our centre. We invited all of these patients to attend the hospital for clinical and radiographic follow-up. As part of this, three scoring systems were completed for each patient; the Short-form 36 health survey (SF36), the Merle d'Aubigné score and the Short Musculoskeletal Functional Assessment (SMFA). Results. The data represents one years activity at a new tertiary referral unit. We idenfied a total of 44 patients who were ten years following ORIF of acetabular fractures in our unit. 21 patients (48%) replied to written invitation and attended the hospital for clinical and radiographic follow-up. A further 7 patients were contacted by telephone and interviewed to guage their rehabilitation. 3 patients had passed away. The remaining 13 patients were not contactable. Of those who attended in person for follow-up; 18 were male and 3 were female. The mean age at follow-up was 40.5 years (Range 27-60). In terms of fracture pattern epidemiology, 43% of patients sustained posterior column and wall fractures, 29% posterior wall, 14% posterior column alone, 9.5% transverse with posterior wall and 9.5% bicolumnar. 2 patients in the follow-up group had total hip replacements. Of the remaining patients the overall mean SF36 score was 78.8% (SD 16.4). The mean SMFA was 14.1% (SD 5). The mean Merle d'Aubigné score was 14.9 (SD 3.2) with 63% graded as good or excellent. Comparison of outcome between sub-groups according to fracture clasification showed no significant difference. Traumatic sciatic nerve injury was sustained by four patients in the follow-up group and all patients continued to complain of ongoing weakness. Of the patients who were contacted via telephone, 2 had total hip replacements. The remaining 5 reported no significant problems with their hips and cited this as the reason for not attending follow-up. Conclusion. Overall the outcome of the patients was more favourable than expected. This was supported by the results of the clinical scoring systems. In some patients this also appeared to be despite poor radiographic findings. Our observations suggest that concomitant injuries, especially sciatic nerve injury have a profound negative influence on the patients' ability to fully rehabilitate. These data provide a valuable tool for the trauma surgeon in providing the patient with an educated prognosis

Acetabular fractures are amongst the most complex fractures. It has been suggested that pre-contouring the fixation plates may save intra-operative time, blood loss, reduce intra-operative fluoroscopy and improve the reduction. The purpose of this study was to assess if the contouring could be done reliably using the mirror image of the uninjured hemipelvis. Using the CT data of 12 specimens with no bony abnormality 3D models were reconstructed. Using computer software (AMIRA, Visage Imaging) the mirror image of the left hemipelvis and the right hemipelvis were superimposed based on landmarks. The distances between the surfaces were then calculated and displayed in the form of colour maps. The colour maps demonstrated that for the areas around were acetabular fixation plates would be placed the differences were small. For the anterior column plate 50% of the specimens had differences of less than 1mm, which based on the work of Letournel and Judet would represent an anatomical reduction. For the posterior column plate 58% had differences of less than 1mm. This study demonstrates that there is considerable symmetry between both hemipelvises and that precontouring on the mirror image of the uninjured side is an accurate, quick and reliable method for precontouring

Achieving precise open reduction and fixation of acetabular fractures by using a plate osteosynthesis is a complex procedure. Increasing availability of affordable 3D printing devices and services now allow to actually print physical models of the patient's anatomy by segmenting the patient's CT image. The data processing and printing of the model however still take too much time and usually the resulting model is rigid and doesn't allow fracture reduction on the model itself. Our proposed solution automatically detects relevant structures such as the fracture gaps and cortical bone while eliminating irrelevant structures such as debris and cancellous bone. This is done by approximating a sphere to the exterior surface of a classic segmented STL model. Stepwise, these approximated vertices are projected deeper into any structure such as the acetabular socket or fractures, following a specific set of rules. The resulting surface model finally is adapted precisely to the primary segmented model. Creating an enhanced surface reconstruction model from the primary model took a median time of 42 sec. The whole workflow from DICOM to enhanced printable 3D file took a median time of 13:25 min. The median time and material needed for the prints without the process was 32:25:36 h and 241,04 g, with the process 09:41:33 h and 65,89 g, which is 70% faster. The price of material was very low with a median of 2,18€ per case. Moreover, fracture reduction becomes possible, allowing a dry-run of the procedure and allowing more precise plate placement. Pre-contouring of osteosynthesis plates by using these 3D printouts was done for eleven patients prior to surgery. These printouts were validated to be accurate by three experiences surgeons and compared to classic segmented models regarding printing time, material cost and reduction ability. The pre-contouring of the plates was safely achievable. Our results show that improving the operative treatment with the help of enhanced 3D printed fracture models seems feasible and needs comparably little time and cost, thus making it a technique that can easily integrated into the clinical workflow

Acetabular fractures are amongst the most complex fractures to treat. It has been suggested that pre-contouring the fixation plates may save intra-operative time, blood loss, reduce intra-operative fluoroscopy and improve the reduction. The purpose of this study was to assess if the contouring could be done reliably using the mirror image of the uninjured hemipelvis. Using the CT data of 12 specimens with no bony abnormality 3D models were reconstructed. Using computer software (AMIRA, Visage Imaging) the mirror image of the left hemipelvis and the right hemipelvis were superimposed based on landmarks. The distances between the surfaces were then calculated. The results were collected in the form of mean distance and colour maps. The mean difference between surfaces ranged from 1.76mm and 8.47mm. The colour maps demonstrated that for the areas around were acetabular fixation plated would be placed the differences were small. For the anterior column plate 6 (50%) of the specimens had differences of less than 1mm, which based on the work of Letournel and Judet would represent an anatomical reduction. (None had a difference of more than 6mm.) For the posterior column plate 7 (58%) had differences of less than 1mm. (None had a difference of more than 3mm. This study demonstrates that there is considerable symmetry between both hemipelvises and that precontouring on the mirror image of the uninjured side is an accurate, quick and reliable method for precontouring. However the symmetry is not exact and the operating surgeon needs to be aware that fine-contouring may be required intra-operatively

Background. Venous thromboembolism (VTE) is a common complication of pelvic and acetabular fracture fixation. There is, however, currently limited data to guide clinical decisions on thromboprophylaxis choice in these patients. Methods. This is a prospective study with retrospective analysis of all the patients who were admitted to the Northern General Hospital between August 2009 and March 2011. 2 consultants using same technique and peri-operative regime carried out all procedures. All patients were administered prophylactic enoxaparin and those who were admitted via another hospital had a pre-operative Doppler scan. Post-operatively all patients were commenced on warfarin, or low molecular weight heparin (enoxaprin) if warfarin was contra-indicated, and was continued for three months after discharge. Results. Eighty-nine patients were admitted during this period of which 25 were treated conservatively and were excluded from the study. The mean age of patients was 39.7 years (range 17 to 83) & 73% of those were men. 65% were involved in RTA and 49% had more than one injury. 46 patients were transferred from another hospital. Of those 3 had DVT confirmed on Dopplers and had IVC filters inserted preoperatively. 52 patients were treated with warfarin and 12 with Clexane. Two patients had warfarin related complications (thigh haematoma and small subdural haematoma). Both were treated conservatively and made a full recovery. Two of the warfarin-treated (3.8%) and one of enoxaparin-treated (8%) patients developed DVT/PE. One of the two warfarin-treated patients had a PE despite having an INR of 4.2 and the other patient upon transferring to local hospital had his warfarin stopped prematurely. Conclusions. The study shows that preoperative enoxaparin followed by postoperative warfarin is an effective thromboprophylaxis regime and is associated with low complication rate

Objective

The optimal positioning of the acetabular component is a relevant prognostic factor in total hip arthroplasty (THA). Because of substantial errors of manual technique in cup placement even with experienced surgeon, computer aided navigation system has been developed in recent years. However, existence of the hardware around acetabulum likely deteriorates the accuracy of the navigation system, namely in revision THA case and postoperative status of pelvic fracture. Here we report a case who we successfully performed THA using CT based navigation system although there were multiple hardware around acetabulum due to osteosynthesis for the previous pelvic fracture.

Major orthopaedic fractures are an independent risk factor for the development of venous thromboembolism (VTE), which are significant causes of preventable morbidity and mortality in trauma patients. Despite thromboprophylaxis, patients who sustain a pelvic or acetabular fracture (PA) continue to have high rates of VTE (12% incidence). Thrombelastography (TEG) is a whole-blood, point-of-care test which provides an overview of the clotting process. Maximal amplitude (MA), from TEG analysis, is the measure of clot strength and values ≥65mm have been used to quantify hypercoagulability and increased VTE risk. Therefore, the primary aim was to use serial TEG analysis to quantify the duration of hypercoagulability, following surgically treated PA fractures. This is a single centre, prospective cohort study of adult patients 18 years or older with surgically treated PA fractures. Consecutive patients were enrolled from a Level I trauma centre and blood draws were taken over a 3-month follow-up period for serial TEG analysis. Hypercoagulability was defined as MA ≥65mm. Exclusion criteria: bleeding disorders, active malignancy, current therapeutic anticoagulation, burns (>20% of body surface) and currently, or expecting to become pregnant within study timeframe. Serial TEG analysis was performed using a TEG6s hemostasis analyzer (Haemonetics Corp.) upon admission, pre-operatively, on post-operative day (POD) 1, 3, 5, 7 (or until discharged from hospital, whichever comes sooner), then in follow-up at 2-, 4-, 6-weeks and 3-months post-operatively. Patients received standardized thromboprophylaxis with low molecular weight heparin for 28 days post-operatively. VTE was defined as symptomatic DVT or PE, or asymptomatic proximal DVT, and all participants underwent a screening post-operative lower extremity Doppler ultrasound on POD3. Descriptive statistics were used to determine the association between VTE events and MA values. For the primary outcome measure, the difference between the MA threshold value (≥65mm) and serial MA measures, were compared using one-sided t-tests (α=0.05). Twenty-eight patients (eight females, 29%) with a mean age of 48±18 years were included. Acetabular fractures were sustained by 13 patients (46%), pelvic fractures by 14 patients (50%), and one patient sustained both. On POD1, seven patients (25%) were hypercoagulable, with 21 patients (78%) being hypercoagulable by POD3, and 17 patients (85%) by POD5. The highest average MA values (71.7±3.9mm) occurred on POD7, where eight patients (89%) were hypercoagulable. At 2-weeks post-operatively, 16 patients (94%) were hypercoagulable, and at four weeks, when thromboprophylaxis was discontinued, six patients (40%) remained hypercoagulable. Hypercoagulability persisted for five patients (25%) at 6-weeks and for two patients (10%) by three months. There were six objectively diagnosed VTE events (21.4%), five were symptomatic, with a mean MA value of 69.3mm±4.3mm at the time of diagnosis. Of the VTE events, four occurred in participants with acetabular fractures (three male, 75%) and two in those with pelvic fractures (both males). At 4-weeks post-operatively, when thromboprophylaxis is discontinued, 40% of patients remained hypercoagulable and likely at increased risk for VTE. At 3-months post-operatively, 10% of the cohort continued to be hypercoagulable. Serial TEG analysis warrants further study to help predict VTE risk and to inform clinical recommendations following PA fractures

Management of acetabular fractures in the elderly population remains somewhat controversial in regards to when to consider is open reduction internal fixation (ORIF) versus acute primary total hip. study aims to (1) describe outcome of this complex problem and investigate predictors of successful outcome. This retrospective study analyzes all acetabular fractures in patients over the age of 60, managed by ORIF at a tertiary trauma care centre between 2007 and 2018 with a minimum follow up of one year. Of the 117 patients reviewed, 85 patients undergoing ORIF for treatment of their acetabular fracture were included in the analysis. The remainder were excluded based management option including acute ORIF with THA (n=10), two-stage ORIF (n=2), external fixator only (n=1), acute THA (n=1), and conservative management (n=1). The remainder were excluded based on inaccessible medical records (n=6), mislabelled diagnosis (n=6), associated femoral injuries (n=4), acetabular fracture following hemiarthroplasty (n=1). The mean age of the cohort is 70±7 years old with 74% (n=62) of patients being male. Data collected included: demographics, mechanism of injury, Charlson Comorbidity Index (CCI), ASA Grade, smoking status and reoperations. Pre-Operative Radiographs were analyzed to determine the Judet and Letournel fracture pattern, presence of comminution and posterior wall marginal impaction. Postoperative radiographs were used to determine Matta Grade of Reduction. Outcome measures included morbidity-, mortality- rates, joint survival, radiographic evidence of osteoarthritis and patient reported outcome measures (PROMs) using the Oxford Hip Score (OHS) at follow-up. A poor outcome in ORIF was defined as one of the following: 1) conversion to THA or 2) the presence of radiographic OA, combined with an OHS less than 34 (findings consistent with a hip that would benefit from a hip replacement). The data was analyzed step-wise to create a regression model predictive of outcome following ORIF. Following ORIF, 31% (n=26) of the cohort had anatomic reduction, while 64% (n=54) had imperfect or poor reduction. 4 patients did not have adequate postoperative radiographs to assess the reduction. 31 of 84 patients undergoing ORIF had a complication of which 22.6% (n=19) required reoperation. The most common reason being conversion to THA (n=14), which occurred an average of 1.6±1.9 years post-ORIF. The remainder required reoperation for infection (n=5). Including those converted to THA, 43% (n=36) developed radiographic OA following acetabular fracture management. The mean OHS in patients undergoing ORIF was 36 ± 10; 13(16%) had an OHS less than 34. The results of the logistic regression demonstrate that Matta grade of reduction (p=0.017), to be predictive of a poor outcome in acetabular fracture management. With non-anatomic alignment following fixation, patients had a 3 times greater risk of a poor outcome. No other variables were found to be predictive of ORIF outcome. The ability to achieve anatomic reduction of fracture fragments as determined by the Matta grade, is predictive of the ability to retain the native hip with acceptable outcome following acetabular fracture in the elderly. Further research must be conducted to determine predictors of adequate reduction in order to identify candidates for ORIF

Acetabulum fractures caused by civilian firearms represent a unique challenge for orthopaedic surgeons. Treatment strategies should include the assessment of infection risk due to frequently associated abdominal injuries and maintenance of joint function. Still, internationally accepted treatment algorithms are not available. The aim of the study was to increase knowledge about civilian gunshot fractures of the acetabulum by describing their characteristics and management at a high-volume tertiary hospital. All adult patients admitted to our hospital between January 2009 and December 2022 with civilian gunshot fractures of the acetabulum were included in this descriptive retrospective study. In total our institution treated 301 patients with civilian gunshot fractures of the hip joint and pelvis during the observation period, of which 54 involved the acetabulum. Most patients were young males (88,9%) with a mean age of 29 years. Thirty patients (55,6%) had associated intraabdominal or urological injuries. Fracture patterns were mostly stable fractures with minor joint destruction amenable to conservative fracture treatment (n=48, 88,9%). Orthopaedic surgical interventions were performed in 21 patients (38,9%) with removal of bullets in contact with the hip joint via arthrotomy or surgical hip dislocation as most frequent procedures. Most patients received antibiotics on admission (n=49, 90,7%). Fracture related infections of the acetabulum were noted in six patients (11,1%) while the mortality in the study population was low with one demised patient (1,9%) due to the trauma burden. Most civilian acetabulum gunshot fractures are associated with intraabdominal or urological injuries. In comparison to the literature on extremity gunshot fractures, there is an increased risk of infection in our study population. The decision for surgical wash-out and bullet removal should be based on contamination and anticipated joint destruction, while osteosynthesis or primary arthroplasty are rarely necessary for these injuries

Acetabular fractures, particularly in the geriatric population are on the rise. A recent study indicated a 2.4-fold increase in the incidence of acetabular fractures, with the fastest rising age group, those older than the age of 55. Controversy exists as to the role and indications for total hip arthroplasty (THA), particularly in the acute setting. Three common scenarios require further evaluation and will be addressed. 1.) What is the role of THA in the acute setting for young patients (< 55 years old)? 2.) What is the role and indications for THA in the older patient population (>55 years) and what are surgical tips to address these complex issues? 3.) What are the outcomes of THA in patients with prior acetabular fractures converted to THA?. Acetabular fractures in young patients are often the result of high energy trauma and are a life changing event. In general, preservation of the native hip joint and avoidance of arthroplasty as the first line treatment should be recommended. A recent long-term outcome study of 810 acetabular fractures treated with Open Reduction and Internal Fixation (ORIF) demonstrated 79% survivorship at 20 years with need for conversion to THA as the endpoint. Risk factors for failure were older age, degree of initial fracture displacement, incongruence of the acetabular roof and femoral head cartilage lesions. In selected younger patients, certain fracture types with concomitant injuries to articular surfaces may best be treated by acute THA. In the elderly patient population, acetabular fractures are more likely the result of low energy trauma but often times result in more displacement, comminution and damage to the articular surface. Osteoporosis and generalised poor bone quality make adequate reduction and fixation a challenge in these acute injuries. As such, the role of acute arthroplasty is becoming more widespread. Consideration should be given to delayed arthroplasty in certain patients to allow time for fracture healing followed by THA. However, early mobilization and weight bearing is important in the elderly population and consideration should be given to acute THA. The challenge remains gaining appropriate acetabular fixation in the fractured, osteoporotic bone. Early results showed high complication rates with acetabular fixation. However, newer fixation surfaces and advances in ORIF techniques have led to improved results. In addition, the need for complex acetabular reconstruction with the use of cages or cup cage constructs may be required in this setting. Appropriate 3-D imaging is essential to evaluate the extent of involvement of the anterior and posterior columns as well as the acetabular walls. Mears et al. reported on 57 patients who underwent THA for acute acetabular fracture and reported results at a mean of 8.1 years. 79% of patient reported good or excellent results and no acetabular cups were revised for loosening. One of the more common scenarios is the patient that presents with a prior ORIF of an acetabular fracture that has developed post-traumatic arthritis or avascular necrosis of the hip and requires conversion to THA. Challenges in this patient population include dealing with prior hardware that may interfere with THA component fixation, severe stiffness of the joint making exposure difficult and prior heterotopic ossification that may put neurovascular structures at risk. Previous studies have demonstrated lower long-term survivorship of the acetabular component (71% at 20 years) compared to primary THA for osteoarthritis. New acetabular fixation surfaces should mitigate the risk of aseptic loosening in this challenging patient population

The reconstruction of peri-acetabular defects after severe bone loss or pelvic resection for tumor is among the most challenging surgical intervention. The Lumic® prosthesis (Implantcast, Buxtehude, Germany) was first introduced in 2008 in an effort to reduce the mechanical complications encountered with the classic peri-acetabular reconstruction techniques and to improve functional outcomes. Few have evaluated the results associated with the use of this recent implant. A retrospective study from five Orthopedic Oncology Canadian centers was conducted. Every patient in whom a Lumic® endoprosthesis was used for reconstruction after peri-acetabular resection or severe bone loss with a minimal follow-up of three months was included. The charts were reviewed and data concerning patients’ demographics, peri-operative characteristics and post-operative complications was collected. Surgical and functional outcomes were also assessed. Sixteen patients, 11 males and five females, were included and were followed for 28 months [3 – 60]. Mean age was 55 [17–86], and mean BMI reached 28 [19.6 – 44]. Twelve patients (75%) had a Lumic® after a resection of a primary sarcoma, two following pelvic metastasis, one for a benign tumor and one after a comminuted acetabular fracture with bone loss. Twelve patients (75%) had their surgery performed in one stage whereas four had a planned two-stage procedure. Mean surgical time was 555 minutes [173-1230] and blood loss averaged 2100 mL [500-5000]. MSTS score mean was 60.3 preoperatively [37.1 – 97] and 54.3 postoperatively [17.1-88.6]. Five patients (31.3%) had a cemented Lumic® stem. All patients got the dual mobility bearing, and 10 patients (62.5%) had the largest acetabular cup implanted (60 mm). In seven of these 10 patients the silver coated implant was used to minimize risk of infection. Five patients (31.3%) underwent capsular reconstruction using a synthetic fabric aiming to reduce the dislocation risk. Five patients had per-operative complications (31.3%), four were minor and one was serious (comminuted iliac bone fracture requiring internal fixation). Four patients dislocated within a month post-operatively and one additional patient sustained a dislocation one year post-operatively. Eight patients (50%) had a post-operative surgical site infection. All four patients who had a two-stage surgery had an infection. Ten patients (62.5%) needed a reoperation (two for fabric insertion, five for wash-outs, and three for implant exchange/removal). One patient (6.3%) had a septic loosening three years after surgery. At the time of data collection, 13 patients (81.3%) were alive with nine free of disease. Silver coating was not found to reduce infection risk (p=0.2) and capsuloplasty did not prevent dislocation (p=1). These results are comparable to the sparse data published. Lumic® endoprosthesis is therefore shown to provide good functional outcomes and low rates of loosening on short to medium term follow-up. Infection and dislocation are common complications but we were unable to show benefits of capsuloplasty and of the use of silver coated implants. Larger series and longer follow-ups are needed