Meir Marmor

Limitations of Standard Fluoroscopy in Detecting Rotational Malreduction of the Syndesmosis in an Ankle Fracture Model

Background: When treating ankle fractures with associated syndesmosis injury, failure to anatomically reduce the syndesmosis may lead to poor outcome. While shortening and posterior subluxation of the distal fibula are readily detected by intraoperative fluoroscopy, it is unclear how well malrotation can be assessed. The ability of fluoroscopy to detect rotational malre-duction of the fibula was the subject of this study. Materials and Methods: Distal fibula fractures with complete syndesmotic injury were produced in ten cadaveric ankles. Two Kirschner wires were used to fix the fibula in neutral (0 degrees), 10 to 30 degrees of external rotation (ER), and 10 degrees to 30 degrees of internal rotation (IR). Using C-arm fluoroscopy tibio-fibular clear space and tibio-fibular overlap in the AP and mortise views, and posterior fibular subluxation in the lateral view were measured to assess reduction of the syndesmosis. Results: The radiographic indices were able to detect as little as 10 degrees of IR but were within their normal range in up to 30 degrees of ER. When assessing for a 2mm difference compared to the intact ankle, sensitivity of all indices were low after more than 15 degrees ER, but high and clinically useful after more than 15 degrees of IR. Conclusion: Radiographic indices for syndesmosis disruption could not detect ER malreduction of the syndesmosis of up to 30 degrees. Clinical Relevance: In the setting of ankle fractures with syndesmosis disruption, fixing the fibula in as much as 30 degrees of external rotation may go undetected using intraoperative fluoroscopy alone.

Tibial plateau fracture repairs augmented with calcium phosphate cement have higher in situ fatigue strength than those with autograft.

Objectives: This study compared the biomechanical fatigue strength of calcium phosphate augmented repairs versus autogenous bone graft (ABG) repairs in lateral tibia plateau fractures. Methods: Eight matched pairs of tibias (six male, two female; age, 75 ± 14 years) were harvested from fresh-frozen cadavers. Reproducible split-depression fractures were simulated and repaired by an orthopaedic traumatologist using a lateral tibial plateau plate. One tibia from each donor was randomly assigned to either calcium phosphate (Callos; Acumed, Hillsboro, OR) or ABG as augmentation. The femoral component of a hemitotal knee arthroplasty was attached to the actuator of a servohydraulic press and centered above the repair site. Cyclic, physiological compression loads were applied at 4Hz starting with a maximum load of 15% body weight and increasing by 15% body weight every 70,000 cycles. Loading conditions were determined from calculations of weight distribution, joint contact area, and gait characterization from existing literature. Repair site depression and stiffness were measured at regular intervals. Specimens were then loaded to failure at 1 mm/min. Results: Calcium phosphate augmented repairs subsided less and were more stiff during the fatigue loading than were ABG repairs at the 70,000, 140,000, and 210,000 cycle intervals (P < 0.03) All repairs survived to 210,000 cycles. The average ultimate load of the calcium phosphate repairs was 2241 ± 455 N (N = 6) and 1717 ± 508 N (N = 8) for ABG repairs (P = 0.02). Conclusion: Calcium phosphate repairs have significantly higher fatigue strength and ultimate load than ABG repairs and may increase the immediate weightbearing capabilities of the repaired knee.

Acute Complications of Patients With Pelvic Fractures After Pelvic Angiographic Embolization

BackgroundHemodynamically unstable patients with a pelvic fracture and arterial pelvic bleeding frequently are treated with pelvic angiographic embolization (PAE). PAE is reported to be a safe and effective method of controlling hemorrhage. However, the loss of blood supply and subsequent ischemia from embolization may lead to adverse consequences.Objectives/purposesWe sought to determine (1) the frequency and types of complications observed after PAE; (2) the mortality after PAE; and (3) the clinical factors associated with complications and mortality after PAE.MethodsWe conducted a retrospective case series descriptive study at a Level I trauma center. Using our institution’s trauma registry, we isolated patients with pelvic fractures treated with PAE admitted between June 1999 and December 2007. Complications attributed to PAE occurring in the initial hospital stay were recorded. We identified 98 patients with pelvic fractures treated by PAE with an average hospital stay of 25.3 days.ResultsThe complication rate was 11% and included six patients with gluteal muscle necrosis (6%), five with surgical wound breakdown (5%), four deep infections (4%), one superficial infection, two patients with of impotence (2%), and one with bladder necrosis. The mortality rate in the PAE group reached 20%. Bilateral embolization was performed in 100% of the patients with complications. Nonselective embolization was performed in 81% of patients with complications. All of the patients with gluteal necrosis had bilateral nonselective embolization.ConclusionsBilateral or nonselective PAE is associated with significant complications during the initial hospital stay. The value of PAE should be weighed against its possible adverse consequences. Selective unilateral arterial embolization should be considered whenever possible.Level of EvidenceLevel IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Rotational malreduction of the syndesmosis: reliability and accuracy of computed tomography measurement methods.

Background: Computed tomography (CT)-based indices may be superior to plain radiographs in determining the adequacy of reduction following operative fixation of the syndesmosis in unstable ankle fractures. This study assessed the reliability and accuracy of four CT-based methods for measurement of rotational malreduction of the fibula. Methods: A simulated Weber C ankle fracture was created by performing an osteotomy in 9 cadaver ankles. The fibula was rotated and fixed in neutral (0 degrees) and 10 to 30 degrees of internal and external rotation. Fifty-two CT images at the level of the syndesmosis were obtained in neutral and rotated positions and presented in random order to 3 independent observers. Measurements were made using commercial imaging software and 4 methods for interpreting CT scans. Interobserver reliability and accuracy were assessed and compared. Results: Methods 1 and 4 showed high anatomic variability. Methods 1, 2, and 4 had a test-retest repeatability of about 15 degrees. Method 1 varied erratically with direction and degree of malrotation (R2 = 0.15) and did not permit specification of a neutral range. Method 2 varied consistently and systematically with direction and degree of malrotation (R2 = 0.88). Receiver operating characteristic curve analysis indicated that method 2 identified malrotation better than did the other methods. Methods 3 and 4 were somewhat more difficult to perform. Conclusions: Method 2, the angle between the tangent of the anterior tibial surface and the bisection of the vertical midline of the fibula at the level of the incisura, was fairly reliable and accurate and had greater ease of measurement compared with the other methods that were tested. Clinical Relevance: This study demonstrated that assessment of malrotation of fibular fractures by CT scan can be difficult. We believe that of the 4 methods tested in this study, method 2, the angle between the tangent of the anterior tibial surface and the bisection of the vertical midline of the fibula at the level of the incisura, was the most useful.

Fracture Surgery of the extremities with the intra-operative use of 3D-RX: A randomized multicenter trial (EF3X-trial)

BackgroundPosttraumatic osteoarthritis can develop after an intra-articular extremity fracture, leading to pain and loss of function. According to international guidelines, anatomical reduction and fixation are the basis for an optimal functional result. In order to achieve this during fracture surgery, an optimal view on the position of the bone fragments and fixation material is a necessity. The currently used 2D-fluoroscopy does not provide sufficient insight, in particular in cases with complex anatomy or subtle injury, and even an 18-26% suboptimal fracture reduction is reported for the ankle and foot. More intra-operative information is therefore needed.Recently the 3D-RX-system was developed, which provides conventional 2D-fluoroscopic images as well as a 3D-reconstruction of bony structures. This modality provides more information, which consequently leads to extra corrections in 18-30% of the fracture operations. However, the effect of the extra corrections on the quality of the anatomical fracture reduction and fixation as well as on patient relevant outcomes has never been investigated.The objective of this study protocol is to investigate the effectiveness of the intra-operative use of the 3D-RX-system as compared to the conventional 2D-fluoroscopy in patients with traumatic intra-articular fractures of the wrist, ankle and calcaneus. The effectiveness will be assessed in two different areas: 1) the quality of fracture reduction and fixation, based on the current golden standard, Computed Tomography. 2) The patient-relevant outcomes like functional outcome range of motion and pain. In addition, the diagnostic accuracy of the 3D-RX-scan will be determined in a clinical setting and a cost-effectiveness as well as a cost-utility analysis will be performed.Methods/designIn this protocol for an international multicenter randomized clinical trial, adult patients (age > 17 years) with a traumatic intra-articular fracture of the wrist, ankle or calcaneus eligible for surgery will be subjected to additional intra-operative 3D-RX. In half of the patients the surgeon will be blinded to these results, in the other half the surgeon may use the 3D-RX results to further optimize fracture reduction. In both randomization groups a CT-scan will be performed postoperatively. Based on these CT-scans the quality of fracture reduction and fixation will be determined. During the follow-up visits after hospital discharge at 6 and 12 weeks and 1 year postoperatively the patient relevant outcomes will be determined by joint specific, health economic and quality of life questionnaires. In addition a follow up study will be performed to determine the patient relevant outcomes and prevalence of posttraumatic osteoarthritis at 2 and 5 years postoperatively.DiscussionThe results of the study will provide more information on the effectiveness of the intra-operative use of 3D-imaging during surgical treatment of intra-articular fractures of the wrist, ankle and calcaneus. A randomized design in which patients will be allocated to a treatment arm during surgery will be used because of its high methodological quality and the ability to detect incongruences in the reduction and/or fixation that occur intra-operatively in the blinded arm of the 3D-RX. An alternative, pragmatic design could be to randomize before the start of the surgery, then two surgical strategies would be compared. This resembles clinical practice better, but introduces more bias and does not allow the assessment of incongruences that would have been detected by 3D-RX in the blinded arm.Trial registrationDutch Trial Register NTR 1902

Superior Gluteal Artery Injury During Iliosacral Screw Placement due to Aberrant Anatomy

Percutaneous iliosacral screws are considered the standard of care for disruptions of the sacroiliac joint. This article describes a case of iatrogenic injury to the superior gluteal artery during iliosacral screw insertion and analyzes the possible reasons for this complication.A 32-year-old man diagnosed with an unstable pelvic ring injury underwent percutaneous fixation of the right sacroiliac joint. A 2-cm skin incision was made, and a straight cannulated awl was placed with the tip directly lateral to the S1 body. A guide wire was inserted and a partially threaded 6.5-mm cannulated screw with a washer was then placed over the guide wire and was found to be in excellent position. At this time, increased bleeding from the incision was observed. The incision was enlarged and dissection was carried down through the muscle. The bleeding vessel could not be visualized. Therefore, the wound was packed with sponges, and coil embolization of the right superficial gluteal artery was successfully performed.Analysis of the angiography reveled that our patients superficial branch of the superior gluteal artery measured more than twice the average length reported in a previous anatomic study. We believe this is the first case of superior gluteal artery bleeding due to aberrant superior gluteal artery anatomy. When planning iliosacral screw insertion, the possibility of anatomical variance of the superior gluteal artery should be acknowledged and sought after in preoperative angiography, when available.

Survivorship and Severe Complications Are Worse for Octogenarians and Elderly Patients with Pelvis Fractures as Compared to Adults: Data from the National Trauma Data Bank

Purpose. This study examined whether octogenarians and elderly patients with pelvic fractures have a different risk of complication and mortality as compared to adults. Methods. Data was gathered from the National Trauma Data Bank from 2002 to 2006. There were 32,660 patients 18–65, 6,408 patients 65–79, and 5,647 patients ≥ 80 years old with pelvic fractures. Descriptive statistics and bivariate and multivariate analyses were performed with the adult population as a referent. Results. Multivariate analysis showed 4.7-fold higher odds of death and 4.57 odds of complications in the octogenarian group after a pelvic fracture compared to adults. The elderly had 1.81-fold higher odds of death and 2.18-fold higher odds of severe complications after sustaining a severe pelvic fracture relative to adults. An ISS ≥ 16 yielded 15.1-fold increased odds of mortality and 18.3-fold higher odds of severe complications. Hypovolemic shock had 7.65-fold increased odds of death and 6.31-fold higher odds of severe complications. Between the ages of 18 and 89 years, there is approximately a 1% decrease in survivorship every 10 years. Conclusions. This study illustrates that patients older than 80 years old with pelvis fractures have a higher mortality and complications rate than elderly or adult patients.

Reduction of Radiation Exposure From C-Arm Fluoroscopy During Orthopaedic Trauma Operations With Introduction of Real-Time Dosimetry.

Objectives: The use of fluoroscopy for indirect guidance in orthopaedic trauma surgery has increased. The purpose of this investigation was to assess how real-time visualization of radiation exposure impacts dose levels during orthopaedic trauma operations. Design: Observational comparative study. Setting: Level 1 trauma center orthopaedic trauma surgery operating room. Patients/Participants: The participants in this study were 83 patients with fractures of the ankle, tibia, femur, or acetabulum receiving definitive surgical fixation of their fracture; children under 18 years of age were excluded from the study. Fellowship trained orthopaedic trauma surgeons, resident orthopaedic surgeons, radiology technicians, and scrub nurses involved in the operations on included fracture patients were also participants. Intervention: Real-time radiation exposure feedback from the Philips DoseAware device. Main Outcome Measurements: Radiation exposure from fluoroscopy compared between phase 1, during which participants were blinded to exposure levels, and phase 2, during which participants were able to see exposure levels in real time. Results: Overall mean radiation exposure was decreased by 60% in phase 2 compared with phase 1 (P = 0.023). Mean surgeon (MS; average of primary and assistant surgeon) and mean nonsurgeon personnel (average of x-ray technician, scrub nurse, and patient) radiation exposures were decreased from phase 1 to phase 2, by 58% and 80%, respectively (MS, P = 0.034; mean nonsurgeon personnel, P = 0.043). From phase 1 to phase 2, MS radiation for femoral shaft fractures decreased by 80% or 162.0 &mgr;Sv (P = 0.02) and by 81% or 128.9 &mgr;Sv (P = 0.014) for acetabular fractures. Discussion: Our data demonstrate that real-time visualization of radiation exposure during orthopaedic trauma operations can decrease radiation exposure in the highest exposure cases. Further research is necessary to determine whether the reduction in radiation exposure is sustained over time and to understand how real-time radiation exposure data mitigates exposure. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The effect of fracture pattern stability on implant loading in OTA type 31-A2 proximal femur fractures.

Background: Internal fixation of OTA type 31-A2 proximal femoral fractures can be performed with either a sliding hip screw and side plate (SHS-P) or a sliding hip screw and intramedullary nail (SHS-IMN). Controversy exists as to which is the best implant for these types of fractures. The primary aim of this study was to investigate the stability of 31-A2 fractures as a function of loss of medial cortical buttress. The secondary aim was to assess the influence of fracture stability on the different internal fixation constructs. Methods: Simulated simple intertrochanteric fractures were made in 12 cadaver proximal femurs. Six fractures were fixed with an SHS-P and 6 with an SHS-IMN. Both implants were instrumented with a strain gauge at the lag screw—nail/plate interface to allow assessment of implant load bearing (ILB). A primary fracture line, in accordance with the 31-A2 OTA classification, was created after which 3 subsequent horizontal osteotomies in 1-cm increments were made across the medial cortex. Compressive loading up to 1050 N was performed after each osteotomy. Results: ILB was presented as percentage of maximal ILB. SHS-P constructs increased their load bearing gradually. For SHS-P constructs, ILB was 8.1% ± 1.8% in the intact state, increasing to 49.6% ± 14.0% after the initial intertrochanteric osteotomy (P = 0.0002), 68.7% ± 15.9% after the first medial osteotomy (P = 0.028), and 80.0% ± 15.9% after the second medial osteotomy (P = 0.15). After the first-level medial osteotomy, SHS-IMN constructs reached a plateau in which the implant carried the entire load. Conclusions: Type 31-A2 fractures become increasingly unstable with increased medial comminution (or fragment size). SHS-P constructs were more load sharing than SHS-IMN constructs. These findings may help guide the surgeon in choice of implant for a 31-A2 intertrochanteric fracture, leaning toward SHS-IMN for the more unstable fracture patterns.

Cementless fixation in total knee arthroplasty

In this study we present our experience with four generations of uncemented total knee arthroplasty (TKA) from Smith & Nephew: Tricon M, Tricon LS, Tricon II and Profix, focusing on the failure rates correlating with each design change. Beginning in 1984, 380 Tricon M, 435 Tricon LS, 305 Tricon 2 and 588 Profix were implanted by the senior author. The rate of revision for loosening was 1.1% for the Tricon M, 1.1% for the Tricon LS, 0.5% for the Tricon 2 with a HA coated tibial component, and 1.3% for the Profix TKA. No loosening of the femoral component was seen with the Tricon M, Tricon LS or Tricon 2, with no loosening seen of the tibial component with the Profix TKA. Regarding revision for wear, the incidence was 13.1% for the Tricon M, 6.6% for the Tricon LS, 2.3% for the Tricon 2, and 0% for the Profix. These results demonstrate that improvements in the design of uncemented components, including increased polyethylene thickness, improved polyethylene quality, and the introduction of hydroxyapatite coating, has improved the outcomes of uncemented TKA over time.