Insertion sites of iliosacral screws on the posterior ilium: Implications for posterior pelvic fixation.

OBJECTIVES: Lateral compression type II pelvic ring injuries can be treated with fixation through open or percutaneous approaches depending on the injury pattern and available osseous fixation pathways. The start site of iliosacral screws to stabilize these injuries should be on the unstable posterior iliac fragment; however, our understanding of start sites for iliosacral screws has not been developed. The purpose of this study is to provide an analysis of iliosacral screw start sites on the posterior ilium to help guide treatment of pelvic ring injuries. METHODS: One-hundred and seventeen consecutive patients at an academic level I trauma center with pelvic ring injuries who underwent surgical treatment with iliosacral screws were included in the final analysis. The start sites of iliosacral screws with confirmed intraosseous placement on a postoperative computed tomography were mapped on the posterior ilium and analyzed according to the sacral segment and type of iliosacral screw. RESULTS: One-hundred and seventeen patients were included in the final analysis. Of the total of 272 iliosacral screw insertion sites analyzed, 145 (53%) were sacroiliac-style screws and 127 (47%) were transsacral screws. The insertion sites for sacroiliac-style screws and transsacral screws at different sacral segment levels can vary but have predictable regions on the posterior ilium relative to reliable osseous landmarks. CONCLUSIONS: Iliosacral screws start sites on the posterior ilium have reliable regions that can be used to plan posterior fixation of pelvic ring injuries.

Outcomes of isolated medial tibial plateau fractures by fracture morphology.

PURPOSE: To identify a cohort of isolated medial tibial plateau fractures treated with surgical fixation and to categorize them by Moore and Wahlquist classifications in order to determine the rate of complications with each fracture morphology and the predictive value of each classification system. We hypothesized there would be high rates of neurovascular injury, compartment syndrome, and complications overall with a higher incidence of neurovascular injury in Moore type III rim avulsion fractures and Wahlquist type C fractures that enter the plateau lateral to the tibial spines. METHODS: Patients who presented to six Level I trauma centers between 2010 and 2021 who underwent surgical fixation for isolated medial tibial plateau fractures were retrospectively reviewed. Data including demographics, radiographs, complications, and functional outcomes were collected. RESULTS: One hundred and fifty isolated medial tibial plateau fractures were included. All patients were classified by the Wahlquist classification of medial tibial plateau fractures, and 139 patients were classifiable by the Moore classification of tibial plateau fracture-dislocations. Nine percent of fractures presented with neurovascular injury: 5 % with isolated vascular injury and 6 % with isolated nerve injury. There were no significant differences in neurovascular injury by fracture type (Wahlquist p = 0.16, Moore p = 0.33). Compartment syndrome developed in two patients (1.3 %). The average final range of motion was 0.8-122° with no difference by Wahlquist or Moore classifications (p = 0.11, p = 0.52). The overall complication rate was 32 % without differences by fracture morphology. The overall rate of return to the operating room (OR) was 25 %. CONCLUSIONS: Isolated medial tibial plateau fractures often represent fracture-dislocations of the knee and should receive a meticulous neurovascular exam on presentation with a high suspicion for neurovascular injury. No specific fracture pattern was found to be predictive of neurovascular injuries, complications, or final knee range of motion. Patients should be counseled pre-operatively regarding high rates of return to the OR after the index surgery.

Low reoperation rate after fixation of displaced femoral neck fractures with the femoral neck system (FNS).

PURPOSE: Operative fixation of femoral neck fractures (FNFs) remains challenging. Complications are not infrequent, especially in displaced patterns. Numerous fixation techniques have been previously described in the literature; however, there remains a paucity of data regarding outcomes of these injuries treated with the femoral neck system (FNS). METHODS: Patients with a displaced FNF (OTA/AO 31B) treated with the FNS at a single level 1 academic trauma center between 1/1/2019 and 1/1/2023 were identified. Radiographs were reviewed to assess fracture displacement, location, and characteristics. Patient records were further reviewed to assess for complications, reoperations, and osseous union. RESULTS: Forty-three patients (65% male) with 44 FNFs were identified with a mean age of 35.0 years (range, 13-61 years). Two patients developed a deep infection requiring surgical debridement, four patients underwent a total hip arthroplasty, and one patient underwent a valgus intertrochanteric osteotomy for nonunion. There were three cases of femoral head AVN. Mean follow-up was 482.5 days among all patients, and 36 fractures had at least 6 months of follow-up or reached bony union. CONCLUSIONS: Here, we present a series of patients treated with the FNS for internal fixation and report a 18% reoperation rate. This is lower than the average rate that has been previously reported in similar patient populations in the literature treated with alternative methods of internal fixation. Thus, the FNS appears to be a safe and effective option for treatment of these injuries.

Titanium versus stainless steel alloy bridge plates for distal femur fractures: Does callus form earlier with titanium?

INTRODUCTION: Distal femur fractures account for 3-6% of all femur fractures. Internal fixation of most distal femur fractures with an anatomic lateral locking plate should permit some motion at the metaphyseal portion of the fracture when secondary bone healing is planned by the operating surgeon. While several studies have been performed evaluating union rates for distal femur fractures with stainless steel and titanium plates, the timing of callus formation between stainless steel and titanium implants used as bridge plates for distal femur fractures (AO/OTA 33-A and -C) has been investigated to a lesser extent. We hypothesize that callus will be visualized earlier with post-operative radiographs with titanium versus stainless steel bridge plates. METHODS: We retrospectively reviewed a consecutive cohort of patients over 18 years of age with acute AO/OTA 33-A and 33-C fracture patterns treated with an isolated stainless steel or titanium lateral bridge plate within 4 weeks of injury by a single fellowship-trained orthopedic trauma surgeon from 2011 to 2020 at one academic Level 1 trauma center. An independent, fellowship-trained orthopedic trauma attending surgeon reviewed anterior-posterior (AP) and lateral radiographs from every available post-operative clinic visit and graded them using the Modified Radiographic Score for Tibia (mRUST). RESULTS: Twenty-five subjects were included in the study with 10 with stainless steel and 15 with titanium plates. There were no significant differences in demographics between both groups, including age, sex, BMI, injury classification, open versus closed, mechanism, and laterality. Statistically significant increased mRUST scores, indicating increased callus formation, were seen on 12-week radiographs (8.4 vs. 11.9, p = 0.02) when titanium bridge plates were used. There were no statistically significant differences in mRUST scores at 6 or 24-weeks, but scores in the titanium group were higher in at every timepoint. DISCUSSION: In conclusion, we observed greater callus formation at 12 weeks after internal fixation of 33-A and 33-C distal femur fractures treated with titanium locked lateral distal femoral bridge plates compared to stainless steel plates. Our data suggest that titanium metallurgy may have quicker callus formation compared to stainless steel if an isolated, lateral locked bridge plate is chosen for distal femur fracture fixation.

MRI characteristics of radiographically occult femoral neck fractures in trauma patients with ipsilateral femoral shaft fractures.

PURPOSE: Ipsilateral femoral neck fractures can be seen alongside femoral shaft fractures in high-velocity trauma patients. These neck fractures are often occult on radiographs and CT, and can have a significant impact on patient outcomes if not treated promptly. Limited protocol pelvic MRI has been used to increase sensitivity for these occult fractures. Detailed characterization of these fractures on MRI is lacking. METHODS: 427 consecutive trauma patients presenting to our emergency department who had known femoral diaphyseal fractures but no ipsilateral femoral neck fracture on radiographs or CT were included in this study. These patients were scanned using a limited protocol MRI with coronal T1 and coronal STIR sequences. Presence of an ipsilateral femoral neck fracture and imaging characteristics of the fracture were obtained. RESULTS: 31 radiographically occult ipsilateral femoral neck fractures were found, representing 7% of all cases. All neck fractures were incomplete. All fractures originated along the lateral cortex of the femoral neck and extended medially towards the junction of the medial femoral neck and the lesser trochanter. 58% (18/31) were vertical in orientation. 61% (19/31) did not demonstrate any appreciate edema on STIR images. CONCLUSION: Implementation of limited protocol MRI protocol increases sensitivity for detection of femoral neck fractures in the setting of ipsilateral femoral shaft fractures not seen on radiograph or CT imaging. We describe the characteristic MR imaging features of these fractures.

Retrograde intramedullary nailing of AO/OTA 33C femur fractures in patients with below-knee amputations: technical note and case series.

PURPOSE: Intra-articular distal femur fractures in patients with a lower extremity amputation can present a technical challenge for the treating surgeon in what may be otherwise considered a routine procedure in non-amputees. Difficulties with positioning, fracture reduction, limb contractures, and stump osteoporosis can present challenges with treatment. Here, we describe the surgical technique and outcome of a case series of amputee patients with AO/OTA 33C femur fractures. METHODS: Retrospective case series of five patients with a comminuted supracondylar distal femur fracture with intercondylar extension proximal to a below-knee amputation treated with retrograde intramedullary nail at a single Level 1 trauma center from January 1, 2021, to January 1, 2023. Baseline demographic and clinical data were recorded. Rate of bony union and complications were documented. RESULTS: Five patients (three females and two males) with a mean age of 48 years who were treated for a comminuted supracondylar distal femur fracture with intercondylar extension proximal to a below-knee amputation were identified. At the time of final follow-up (mean 109.3 days, range 29-183 days), all patients had healed their incisions and were progressing to return of function with their prosthesis. All patients were treated with the surgical technique described in this article, and no postoperative complications were reported. CONCLUSION: This is an effective and safe technique for surgical treatment of comminuted intra-articular distal femur fractures in patients with an ipsilateral below-knee amputation. We believe that this technique can be utilized by any orthopedic surgeon taking trauma call and can avoid unnecessary transfers or delays to care.

Lateral rim variable angle locked plating versus tension band wiring of simple and complex patella fractures: a biomechanical study.

INTRODUCTION: Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. MATERIALS AND METHODS: Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking. RESULTS: For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01. CONCLUSIONS: From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.

Does local fat thickness correlate with post-operative infection in open reduction and internal fixation of acetabulum fractures?

PURPOSE: Obesity is an epidemic which increases risk of many surgical procedures. Previous studies in spine and hip arthroplasty have shown that fat thickness measured on preoperative imaging may be as or more reliable in assessment of risk of post-operative infection and/or wound complications than body mass index (BMI). We hypothesized that, similarly, increased local fat thickness at the surgical site is a predictor of wound complication in acetabulum fracture surgery. METHODS: Patients who underwent open reduction and internal fixation (ORIF) of an acetabulum fracture through a Kocher-Langenbeck (K-L) approach at a single institution from 2013 to 2020 were identified. Pre-operative CT scans were used to measure fat thickness from the skin to the greater trochanter in line with the surgical approach. Post-operative infections and wound complications were recorded and associated with fat thickness and BMI. RESULTS: 238 patients met inclusion criteria. 12 patients had either infection or a wound complication (5.0%). There was no significant association with BMI or preoperative fat thickness on post-operative infection or wound complication (p-value 0.73 and 0.86). CONCLUSIONS: There is no statistically significant association of post-operative infection or wound complications in patients with increased soft tissue thickness or increased BMI. ORIF of acetabulum fractures through a K-L approach can be performed safely in patients with large subcutaneous fat thickness and high BMI with low risk of infection or wound complications.

Multidimensional Fluoroscopy to Assess Closed Reduction in Displaced Young Femoral Neck Fractures: A Report of 3 Cases.

CASE: The authors present 3 physiologically young patients with displaced femoral neck fractures who underwent initial closed reduction and provisional fixation. Multidimensional fluoroscopy was used to assess fracture reduction before definitive fixation, with 1 patient requiring an open approach because of inadequate fracture reduction after closed attempts. CONCLUSION: Displaced femoral neck fractures in young patients remain difficult injuries to treat. Reduction quality is a significant predictor of patient outcomes. Intraoperative multidimensional fluoroscopy provides treating surgeons with a tool to assess fracture reduction after closed reduction maneuvers and allows for intraoperative treatment adjustment as needed.

Bladder Repair With Irrigation and Debridement and Open Reduction Internal Fixation of the Anterior Pelvic Ring Is Safe and Decreases Risk of Infection in Pelvic Ring Injuries With Extraperitoneal Bladder Ruptures.

OBJECTIVES: To determine the incidence of infection in nonoperative versus operative management of extraperitoneal bladder ruptures in patients with pelvic ring injuries. DESIGN: A retrospective cohort study of 2 prospectively collected trauma registries. SETTING: Two Level 1 trauma centers. PATIENT SELECTION CRITERIA: Patients with operative pelvic ring injuries, 68 (6%) had extraperitoneal bladder ruptures. OUTCOME MEASURES AND COMPARISONS: The primary outcome was the incidence and associated risk factors of deep pelvic infection requiring return to OR for surgical debridement. Secondary outcomes included quality of reduction, other complications, and radiographic union. Comparisons were made based on the status of any associated bladder injury. RESULTS: Of 1127 patients with operative pelvic ring injuries, 68 patients had extraperitoneal bladder ruptures, 55 had bladder repair and 13 did not. Of those 13 without repair, none had ORIF of the anterior pelvic ring. Patients without bladder repair had an increased odds of infection 17-fold compared to patients who did have a repair performed (OR 16.9, 95% CI 1.75 - 164, P = 0.01). Other associated factors for deep pelvic infection included use of suprapubic catheter ( p < 0.02) and a closed reduction of the anterior ring ( p < 0.01). Patients undergoing anterior ring ORIF and bladder repair had improved reductions and no increased infection risk. CONCLUSIONS: Operative repair of extraperitoneal bladder ruptures decreases risk of infection in patients with pelvic ring injuries. Additionally, ORIF of the anterior pelvic ring does not increase the risk of infection and results in better reductions compared to closed reduction. Treatment algorithms for these combined injuries should consider recommending early bladder repair and anterior pelvic ORIF. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Retrograde Intramedullary Nailing Versus Locked Plating for Extreme Distal Periprosthetic Femur Fractures: A Multicenter Retrospective Cohort Study.

OBJECTIVES: To compare clinical and radiographic outcomes after retrograde intramedullary nailing (rIMN) versus locked plating (LP) of "extreme distal" periprosthetic femur fractures, defined as those that contact or extend distal to the anterior flange. DESIGN: Retrospective review. SETTING: Eight academic level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMN or LP. OUTCOME MEASURES AND COMPARISONS: The primary outcome was reoperation to promote healing or to treat infection (reoperation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Outcomes were compared between patients treated with rIMN or LP. RESULTS: Seventy-one patients treated with rIMN and 224 patients treated with LP were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 ± 1.1 vs. LP: 6.0 ± 1.1, P < 0.001) and more patients who were allowed to weight-bear as tolerated immediately postoperatively (rIMN: 45%; LP: 9%, P < 0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group ( P = 0.122). There were no significant differences in nonunion ( P > 0.999), delayed union ( P = 0.079), fixation failure ( P > 0.999), infection ( P = 0.084), or overall reoperation rate ( P > 0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, P = 0.008). CONCLUSIONS: rIMN of extreme distal periprosthetic femur fractures has similar complication rates compared with LP, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Percutaneous sacral screw fixation alone sufficient for mildly displaced U-type sacral fractures with preserved osseous fixation pathways.

PURPOSE: To describe U-type sacral fracture characteristics amenable to percutaneous sacral screw fixation. METHODS: U-type sacral fractures were identified from a trauma registry at a level 1 trauma center from 2014 to 2020. Patient demographics, injury mechanism, fracture characteristics, and fixation construct were retrospectively retrieved. Associations between fracture pattern and surgical fixation were identified. RESULTS: 82 U-type sacral fractures were reviewed. Six treated with lumbopelvic fixation (LPF) and 76 were treated with percutaneous sacral screws (PSS) alone. Patients receiving LBF had greater sacral fracture displacement in coronal, sagittal, and axial planes compared to patients receiving PSS alone (P < 0.05), negating osseous fixation pathways. All patients went onto sacral union and there were no implant failures or unplanned reoperations for either group. CONCLUSION: If osseous fixation pathways are present, U-type sacral fractures can be successfully treated with percutaneous sacral screws. LPF may be indicated in more displaced fractures with loss of spinopelvic alignment. Both techniques for U-type sacral fractures result in reliable fixation and healing without reoperations.

Use of 3D Fluoroscopy to Assist in the Reduction and Fixation of Pelvic and Acetabular Fractures: A Safety and Quality Case Series.

SUMMARY: Multidimensional fluoroscopy has been increasingly used in orthopaedic trauma to improve the intraoperative assessment of articular reductions and implant placement. Owing to the complex osteology of the pelvis, cross-sectional imaging is imperative for accurate evaluation of pelvic ring and acetabular injuries both preoperatively and intraoperatively. The continued development of fluoroscopic technology over the past decade has resulted in improved ease of intraoperative multidimensional fluoroscopy use in pelvic and acetabular surgery. This has provided orthopaedic trauma surgeons with a valuable tool to better evaluate reduction and fixation at different stages during operative treatment of these injuries. Specifically, intraoperative 3D fluoroscopy during treatment of acetabulum and pelvis injuries assists with guiding intraoperative decisions, assessing reductions, ensuring implant safety, and confirming appropriate fixation. We outline the useful aspects of this technology during pelvic and acetabular surgery and report its utility with a consecutive case series at a single institution. The added benefits of this technology have improved the ability to effectively manage patients with pelvis and acetabulum injuries.

Imaging of Pelvic and Acetabular Trauma: Part 1, Osseous Findings.

Pelvic ring injuries and acetabular fractures are complex injuries and are often challenging to treat for a number of reasons. Orthopaedic trauma surgeons critically evaluate pelvic radiographs and CT images to generate an appropriate detailed injury and patient-specific preoperative plan. There are numerous crucial osseous details that surgeons should be aware of. Often, some of the most important factors that affect patients in treatment timing decisions, assessing reduction strategies, and deciding and inserting fixation constructs may be subtle on preoperative imaging. The radiographic and CT imaging findings covered subsequently should be sought out and appreciated preoperatively. Combining all the available osseous information helps the surgeon predict potential pitfalls and adjust surgical plans before incision. Ensuring a methodical and meticulous imaging review allows for the development of a detailed preoperative plan and helps avoid intraoperative missteps. This process will inherently streamline the surgical procedure and optimize the patient's surgical care. Maximizing the accuracy of the preoperative planning process can streamline the treatment algorithm and ultimately contribute to the best possible clinical outcome.

Oblique anterior pelvic external fixator for intraoperative reduction of rotationally unstable pelvic ring injuries.

Incomplete sacroiliac joint injuries are often associated with external rotation and extension deformities on the injured hemipelvis. To appropriately correct this deformity, an oblique reduction force from caudal to cranial and lateral to medial is helpful. These injuries are often associated with traumatic disruption of the pubic symphysis. However, in injuries without traumatic disruption to the pubic symphysis, a two-pin oblique anterior external fixator can be used to obtain and maintain reduction of the sacroiliac joint, while percutaneous fixation is subsequently placed. Through a small case series and three specific patient examples, we demonstrate that the oblique anterior external fixator frame is a simple and effective strategy with the reduction and stabilization process of these multiplanar hemipelvis deformities.

High Nonunion and Amputations Rates With Either Early Intramedullary Nail Removal or Retention for Tibial Shaft Fracture-Related Infections.

OBJECTIVES: To compare debridement, antibiotics, and implant retention (DAIR) and intramedullary nail (IMN) removal with subsequent strategy for fracture stabilization in the treatment of tibia fracture-related infections (FRIs) occurring within 90 days of initial IMN placement. DESIGN: Retrospective case-control. SETTING: Four academic, Level 1 trauma centers. PATIENTS: Sixty-six patients who subsequently received unplanned operative treatment for FRI diagnosed within 90 days of initial tibia IMN. INTERVENTION: DAIR versus IMN removal pathways. MAIN OUTCOME MEASUREMENTS: Fracture union. RESULTS: Twenty-eight patients (42.4%) were treated with DAIR and 38 (57.6%) via IMN removal with subsequent strategy for fracture stabilization. Mean follow-up was 16.3 months. At final follow-up, ultimate bone healing was achieved in 75.8% (47/62), whereas 24.2% (15/62) had persistent nonunion or amputation. No significant difference was observed in ultimate bone healing ( P = 0.216) comparing DAIR and IMN removal. Factors associated with persistent nonunion or amputation were time from injury to initial IMN ( P < 0.001), McPherson systemic host grade B ( P = 0.046), and increasing open-fracture grade, with Gustilo-Anderson IIIB/IIIC fractures being the worst ( P = 0.009). Fewer surgeries after initial FRI treatment were positively associated with ultimate bone healing ( P = 0.029). CONCLUSIONS: Treatment of FRI within 90 days of tibial IMN with DAIR or IMN removal with subsequent strategy for fracture stabilization results in a high rate, nearly 1 in 4, of persistent nonunion or amputation, with neither appearing superior for improving bone healing outcomes. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Imaging of Pelvic and Acetabular Trauma: Part 2, Soft-Tissue Findings.

Pelvic ring injuries and acetabular fractures can be complex and challenging to treat. Orthopaedic trauma surgeons scrutinize pelvic radiographs and accompanying CT images for the osseous details that help create a thorough patient-specific preoperative plan. While the osseous details are incredibly important, the surrounding soft-tissue structures are equally as critical and can have a tremendous effect on both the patient and the surgeon. These findings may change surgery timing, dictate the need for additional surgeons or multidisciplinary teams, and determine the treatment sequence. The structures and potential clinical findings reviewed and demonstrated through example images should be sought out during physical examination and correlative preoperative imaging review. Combining all the available osseous and nonosseous information with a detailed approach helps the surgeon predict potential pitfalls and adjust surgical plans before incision. Maximizing the accuracy of the preoperative planning process can streamline treatment algorithm development and ultimately contribute to the best possible clinical patient outcome.

The Influence of Computerized Tomography Imaging on Treatment of Periprosthetic Proximal Femur Fractures.

Introduction Periprosthetic femur fractures (PPFF) are increasing in incidence and management of such injuries requires a specialized skill set combined with detailed knowledge of component design. To assist with planning, computed tomography (CT) can be used pre-operatively to give a surgeon more information. No study to date has shown the utility of obtaining preoperative CT. The goal of this study is to show that CT is a useful diagnostic adjunct and report any differences in how subspecialties such as orthopedic traumatologists and arthroplasty surgeons use it. Methods Seventeen PPFF cases met our inclusion criteria. They were shown to six faculty, three trauma and three arthroplasty surgeons. They viewed the plain radiographs and then CTs. After each they filled out the same questionnaire that included their assessment of diagnosis and proposed treatment plan both before and after access to CT imaging. Fleiss and Cohen kappa were used to compare inter- and intra-observer reliability. Results The interobserver kappa values (k) in diagnosis were 0.348 pre- and 0.371 post-CT, while trauma and arthroplasty were 0.328 to 0.260 and 0.821 to 0.881 respectively. The interobserver reliability in treatment was 0.336 pre- and 0.254 post-CT, while trauma and arthroplasty were 0.323 to 0.288 and 0.688 to 0.519. For intraobserver the average k for diagnosis and treatment were 0.818 and 0.671. Broken down by subspecialty they were 0.874 and 0.831 and 0.762 and 0.510 for trauma and arthroplasty. There were 11 diagnostic and 24 treatment changes. Conclusion CT provides diagnostic changes 10% and treatment changes 24% of the time. However, it does not lead to greater agreement among the surgeons on either. Arthroplasty uses CT more to guide both their treatment and the diagnosis, and they agree more than trauma surgeons. Most of the treatment changes come from adding or removing a plate, and the most common diagnostic change was shared by A to B1 and B2 to B3. This suggests fracture extension and bone stock are better evaluated by CT.

Biomechanical properties of splint materials while curing.

Many studies have evaluated splint strength at maturity with multiple splint materials, methods, and configurations but none have analyzed splints as they cure. The purpose of this study is to evaluate the properties of different splint materials immediately following activation and as they mature. Splints were dipped for three seconds in two temperatures of water and an additional group of fiberglass with no water was tested as well. Splint weight was taken as an additional measurement to assure homogenous groups. All splints were tested in three-point bending at a constant displacement. The generalized linear model (GLM) including all time frames showed differences in yield load and ultimate loads after three minutes. All ultimate loads occurred at greater than 20° of angulation. Plaster had a much lower displacement at its yield load at all times after 3 min. Plaster had a higher stiffness at 1° of angulation at all time points after six minutes. The GLM that excluded the three-day time showed that the higher temperature increased initial stiffness in the splints at three and six minutes. Fiberglass has a higher yield point and ultimate load when compared to plaster. However, these loads were measured at significant splint angulation for the fiberglass, suggesting that plaster is acting as a true splint. Fiberglass is stronger and faster to cure than plaster. In situations where the surgeon desires the strongest splint, fiberglass may be preferable. However, the initial stiffness of plaster is superior to fiberglass.

Assessment of sacral osseous fixation pathways for same-level dual transiliac-transsacral screw insertion.

INTRODUCTION: The purpose of this study is to (1) describe a pre-operative planning technique using non-reformatted CT images for insertion of multiple transiliac-transsacral (TI-TS) screws at a single sacral level, (2) define the parameters of a sacral osseous fixation pathway (OFP) that will allow for insertion of two TI-TS screws at a single level, and (3) identify the incidence of sacral OFPs large enough for dual-screw insertion in a representative patient population. METHODS: Retrospective review at a level-1 academic trauma center of a cohort of patients with unstable pelvic injuries treated with two TI-TS screws in the same sacral OFP, and a control cohort of patients without pelvic injuries who had CT scans for other reasons. RESULTS: Thirty-nine patients had two TI-TS screws at S1. Eleven patients, all with dysmorphic osteology, had two TI-TS screws at S2. The average pathway size in the sagittal plane at the level the screws were placed was 17.2 mm in S1 vs 14.4 mm in S2 (p = 0.02). Twenty-one patients (42%) had screws that were intraosseous and 29 (58%) had part of a screw that was juxtaforaminal. No screws were extraosseous. The average OFP size of intraosseous screws was 18.1 mm vs. 15.5 mm for juxtaforaminal screws (p = 0.02). Fourteen millimeters was used as a guide for the lower limit of the OFP for safe dual-screw fixation. Overall, 30% of S1 or S2 pathways were ≥ 14 mm in the control group, with 58% of control patients having at least one of the S1 or S2 pathways ≥ 14 mm. CONCLUSIONS: OFPs ≥ 7.5 mm in the axial plane and 14 mm in the sagittal plane on non-reformatted CT images are large enough for dual-screw fixation at a single sacral level. Overall, 30% of S1 and S2 pathways were ≥ 14 mm and 58% of control patients had an available OFP in at least one sacral level.