Employing machine learning to enhance fracture recovery insights through gait analysis.

This study aimed to explore the potential of gait analysis coupled with supervised machine learning models as a predictive tool for assessing post-injury complications such as infection, malunion, or hardware irritation among individuals with lower extremity fractures. We prospectively identified participants with lower extremity fractures at a tertiary academic center. These participants underwent gait analysis with a chest-mounted inertial measurement unit device. Using customized software, the raw gait data were preprocessed, emphasizing 12 essential gait variables. The data were standardized, and several machine learning models, including XGBoost, logistic regression, support vector machine, LightGBM, and Random Forest, were trained, tested, and evaluated. Special attention was given to class imbalance, addressed using the synthetic minority oversampling technique (SMOTE). Additionally, we introduced a novel methodology to compute the post-injury recovery rate for gait variables, which operates independently of the time difference between the gait analyses of different participants. XGBoost was identified as the optimal model both before and after the application of SMOTE. Before using SMOTE, the model achieved an average test area under the ROC curve (AUC) of 0.90, with a 95% confidence interval (CI) of [0.79, 1.00], and an average test accuracy of 86%, with a 95% CI of [75%, 97%]. Through feature importance analysis, a pivotal role was attributed to the duration between the occurrence of the injury and the initial gait analysis. Data patterns over time revealed early aggressive physiological compensations, followed by stabilization phases, underscoring the importance of prompt gait analysis. χ2 analysis indicated a statistically significant higher readmission rate among participants with underlying medical conditions (p = 0.04). Although the complication rate was also higher in this group, the association did not reach statistical significance (p = 0.06), suggesting a more pronounced impact of medical conditions on readmission rates rather than on complications. This study highlights the transformative potential of integrating advanced machine learning techniques like XGBoost with gait analysis for orthopedic care. The findings underscore a shift toward a data-informed, proactive approach in orthopedics, enhancing patient outcomes through early detection and intervention. The χ2 analysis added crucial insights into the broader clinical implications, advocating for a comprehensive treatment strategy that accounts for the patient's overall health profile. The research paves the way for personalized, predictive medical care in orthopedics, emphasizing the importance of timely and tailored patient assessments.

Resident Education and Wellness: A Strategy for Future Pandemics.

The Coronavirus Disease 2019 (COVID-19) pandemic presented a novel challenge to modern healthcare systems and medical training. Resource allocation and risk mitigation dramatically affected resident training. The objective of this article is to develop new strategies to maintain a healthy, competent residency program while combating the unique challenges to resident education and wellness. In 2020, our institution implemented a revolving 3-Team system. While the "Inpatient-Team" delivered direct care, the "Back-up Team" and "Quarantine-Team" managed the telemedicine virtual clinic and education-wellness strategy, respectively. Our 3-Team system allowed delivery of safe, high-quality patient care while optimizing resident education, research, and wellness. The efficient use of technology led to both improved virtual education outside of the hospital and intentional wellness opportunities despite social distancing restrictions. Utilization of virtual platforms for patient care, education, research, and wellness grew out of necessity in this pandemic, yet represent an opportunity for lasting improvement. (Journal of Surgical Orthopaedic Advances 31(3):150-154, 2022).

A Randomized Trial of Preoperative Practice in a Simulated Operative Environment: 3D Printed Pilon Model Improves Resident Performance.

This study assessed the effect of preoperative planning using a 3D-printed periarticular fracture model on operative performance. A complex pilon fracture was 3D-printed, and a preoperative plan was developed. Orthopaedic surgery residents (n = 20) were randomized into two groups. Group 1 performed routine preoperative planning, while Group 2 was also practiced using a 3D-printed construct before performing fixation of the 3D-printed model. Resident performance was assessed using a video motion capture system and evaluated by blinded reviewers. Three residents (3D group) completed fixation within the allotted 45 minutes. The 3D group had less hand distance traveled for step 1 (89 m vs. 162 m, p = 0.04). The 3D group had better performance on three of the four components and more acceptable reductions (6 vs. 0, p = 0.009). Average global rating scale was higher in the 3D group (3.0 vs. 1.7, p = 0.0095). Use of 3D-printed models for preoperative planning improved resident performance. (Journal of Surgical Orthopaedic Advances 31(3):187-192, 2022).

Effect of Intrawound Vancomycin Powder in Operatively Treated High-risk Tibia Fractures: A Randomized Clinical Trial.

Importance: Despite the widespread use of systemic antibiotics to prevent infections in surgically treated patients with fracture, high rates of surgical site infection persist. Objective: To examine the effect of intrawound vancomycin powder in reducing deep surgical site infections. Design, Setting, and Participants: This open-label randomized clinical trial enrolled adult patients with an operatively treated tibial plateau or pilon fracture who met the criteria for a high risk of infection from January 1, 2015, through June 30, 2017, with 12 months of follow-up (final follow-up assessments completed in April 2018) at 36 US trauma centers. Interventions: A standard infection prevention protocol with (n = 481) or without (n = 499) 1000 mg of intrawound vancomycin powder. Main Outcomes and Measures: The primary outcome was a deep surgical site infection within 182 days of definitive fracture fixation. A post hoc comparison assessed the treatment effect on gram-positive and gram-negative-only infections. Other secondary outcomes included superficial surgical site infection, nonunion, and wound dehiscence. Results: The analysis included 980 patients (mean [SD] age, 45.7 [13.7] years; 617 [63.0%] male) with 91% of the expected person-time of follow-up for the primary outcome. Within 182 days, deep surgical site infection was observed in 29 of 481 patients in the treatment group and 46 of 499 patients in the control group. The time-to-event estimated probability of deep infection by 182 days was 6.4% in the treatment group and 9.8% in the control group (risk difference, -3.4%; 95% CI, -6.9% to 0.1%; P = .06). A post hoc analysis of the effect of treatment on gram-positive (risk difference, -3.7%; 95% CI, -6.7% to -0.8%; P = .02) and gram-negative-only (risk difference, 0.3%; 95% CI, -1.6% to 2.1%; P = .78) infections found that the effect of vancomycin powder was a result of its reduction in gram-positive infections. Conclusions and Relevance: Among patients with operatively treated tibial articular fractures at a high risk of infection, intrawound vancomycin powder at the time of definitive fracture fixation reduced the risk of a gram-positive deep surgical site infection, consistent with the activity of vancomycin. Trial Registration: ClinicalTrials.gov Identifier: NCT02227446.

The Quadrilateral Plate in Acetabular Fracture Surgery: What Is It and When Should It Be Addressed?

The quadrilateral plate (QP) is the relatively flat surface of bone in the true pelvis lying directly medial to the acetabulum. This surface is frequently involved in acetabular fractures. Elderly individuals, in particular, commonly sustain anterior column fractures with incomplete or complete posterior hemitransverse fracture lines with associated QP comminution. If QP fracture lines propagate through the superior weight-bearing surface of the acetabulum, the femoral head may displace medially, leading to poor outcomes if not addressed. Fortunately, the collective work of many orthopaedic surgeons has resulted in numerous effective methods for approaching, reducing, and stabilizing the QP and the diverse family of fractures which affect it. A thorough understanding of the QP, its anatomy, radiology, and techniques for fixation, is required to optimize patient outcomes.

Why Make the Cut? Trochanteric Slide Osteotomy Can Improve Exposure to the Anterosuperior Acetabulum.

OBJECTIVE: To define relative increases in visual bony surface area and access to critical landmarks with the addition of a trochanteric slide osteotomy to a Kocher-Langenbeck approach. METHODS: A Kocher-Langenbeck approach followed by a trochanteric slide osteotomy was sequentially performed on 10, fresh-frozen, hemipelvectomy cadaveric specimens. Visual and palpable access to relevant surgical landmarks was recorded. Calibrated digital photographs were taken of each approach and analyzed using Image J. RESULTS: The acetabular surface area exposed was 27.66 (±6.67) cm2 for a Kocher-Langenbeck approach. This increased to and 41.82 (±7.97) cm2 with the addition of a trochanteric osteotomy. The exposed surface area was increased by 51.2% for the trochanteric osteotomy (P < 0.001). The superior margin of the acetabulum could be visualized and palpably accessed in both exposures. Access to the more anterosuperior portions of the acetabulum was consistently possible in the trochanteric osteotomy but not with the Kocher-Langenbeck approach. CONCLUSIONS: A trochanteric osteotomy may visually improve access to the most anterosuperior acetabulum but does not significantly improve surgical access to relevant portions of the superior acetabulum when compared with a Kocher-Langenbeck approach.

Association Between 6-Week Postdischarge Risk Classification and 12-Month Outcomes After Orthopedic Trauma.

Importance: Numerous studies have demonstrated that long-term outcomes after orthopedic trauma are associated with psychosocial and behavioral health factors evident early in the patient's recovery. Little is known about how to identify clinically actionable subgroups within this population. Objectives: To examine whether risk and protective factors measured at 6 weeks after injury could classify individuals into risk clusters and evaluate whether these clusters explain variations in 12-month outcomes. Design, Setting, and Participants: A prospective observational study was conducted between July 16, 2013, and January 15, 2016, among 352 patients with severe orthopedic injuries at 6 US level I trauma centers. Statistical analysis was conducted from October 9, 2017, to July 13, 2018. Main Outcomes and Measures: At 6 weeks after discharge, patients completed standardized measures for 5 risk factors (pain intensity, depression, posttraumatic stress disorder, alcohol abuse, and tobacco use) and 4 protective factors (resilience, social support, self-efficacy for return to usual activity, and self-efficacy for managing the financial demands of recovery). Latent class analysis was used to classify participants into clusters, which were evaluated against measures of function, depression, posttraumatic stress disorder, and self-rated health collected at 12 months. Results: Among the 352 patients (121 women and 231 men; mean [SD] age, 37.6 [12.5] years), latent class analysis identified 6 distinct patient clusters as the optimal solution. For clinical use, these clusters can be collapsed into 4 groups, sorted from low risk and high protection (best) to high risk and low protection (worst). All outcomes worsened across the 4 clinical groupings. Bayesian analysis shows that the mean Short Musculoskeletal Function Assessment dysfunction scores at 12 months differed by 7.8 points (95% CI, 3.0-12.6) between the best and second groups, by 10.3 points (95% CI, 1.6-20.2) between the second and third groups, and by 18.4 points (95% CI, 7.7-28.0) between the third and worst groups. Conclusions and Relevance: This study demonstrates that during early recovery, patients with orthopedic trauma can be classified into risk and protective clusters that account for a substantial amount of the variance in 12-month functional and health outcomes. Early screening and classification may allow a personalized approach to postsurgical care that conserves resources and targets appropriate levels of care to more patients.

A Quantitative Exposure Planning Tool for Surgical Approaches to the Sacroiliac Joint.

OBJECTIVES: To aid in surgical planning by quantifying and comparing the osseous exposure between the anterior and posterior approaches to the sacroiliac joint. METHODS: Anterior and posterior approaches were performed on 12 sacroiliac joints in 6 fresh-frozen torsos. Visual and palpable access to relevant surgical landmarks was recorded. Calibrated digital photographs were taken of each approach and analyzed using Image J. RESULTS: The average surface areas of exposed bone were 44 and 33 cm for the anterior and posterior approaches, respectively. The anterior iliolumbar ligament footprint could be visualized in all anterior approaches, whereas the posterior aspect could be visualized in all but one posterior approach. The anterior approach provided visual and palpable access to the anterior superior edge of the sacroiliac joint in all specimens, the posterior superior edge in 75% of specimens, and the inferior margin in 25% and 50% of specimens, respectively. The inferior sacroiliac joint was easily visualized and palpated in all posterior approaches, although access to the anterior and posterior superior edges was more limited. The anterior S1 neuroforamen was not visualized with either approach and was more consistently palpated when going posterior (33% vs. 92%). CONCLUSIONS: Both anterior and posterior approaches can be used for open reduction of pure sacroiliac dislocations, each with specific areas for assessing reduction. In light of current plate dimensions, fractures more than 2.5 cm lateral to the anterior iliolumbar ligament footprint are amenable to anterior plate fixation, whereas those more medial may be better addressed through a posterior approach.

Heterotopic ossification rates after acetabular fracture surgery are unchanged without indomethacin prophylaxis.

BACKGROUND: We previously found no reduction in heterotopic ossification (HO) rates after acetabular surgery with indomethacin compared with a placebo. We subsequently abandoned routine indomethacin therapy after acetabular surgery but questioned whether the incidence had changed using a posterior approach. QUESTIONS/PURPOSES: We therefore determined (1) the incidence of HO after acetabular fracture surgery through a posterior approach; (2) the incidence of symptoms attributable to HO; and (3) the rate of reoperation for HO. METHODS: We retrospectively reviewed the records of all 423 patients with acetabular fractures following our clinical protocol change; of these, 120 were treated with a Kocher-Langenbeck approach and included. The presence of radiographic HO was documented a minimum of 10 weeks postoperatively using the classification of Brooker et al. Symptoms and reoperations were recorded. RESULTS: The overall incidence of radiographic HO was 47% (56 of 120 patients): 26% Class I-II 13% Class III, and 8% Class IV. Overall, 15% of patients developed symptoms; 3.3% underwent reoperations for excision of HO. There were no major differences between the incidence of moderate and severe HO in this study when compared with the indomethacin and placebo groups from the prior study. CONCLUSIONS: Our incidence of moderate and severe HO has not changed since discontinuing indomethacin. These findings support our institutional decision to abandon routine indomethacin prophylaxis after acetabular surgery. We recommend improved surgical techniques to limit damage to the abductors and improved risk stratification of patients when considering treatment options for HO prophylaxis.

Proximal tibial intra-articular osteotomy for treatment of complex Schatzker type IV tibial plateau fractures with lateral joint line impaction: description of surgical technique and report of nine cases.

This study presents a retrospective review of 8 patients with 9 cases of an uncommon variant of medial tibial plateau fracture treated with a surgical approach not previously described in the literature. The fracture pattern is characterized by a displaced medial tibial plateau fracture with significant central and posterior impaction of the lateral tibial articular surface but an intact lateral cortex. A novel surgical approach with an intra-articular osteotomy of the lateral tibial plateau was used to facilitate visualization, reduction, and instrumentation of the lateral articular injury. Early clinical and radiographic results of this treatment approach were reviewed. We describe the fracture pattern, surgical technique, and early results and propose this technique as a reasonable alternative for treatment of a challenging clinical entity.

Prospective observational study of donor-site morbidity following anterior iliac crest bone-grafting in orthopaedic trauma reconstruction patients.

BACKGROUND: Complications associated with iliac crest bone-graft donor sites have been reported. This prospective study was conducted to determine the prevalence of pain and complications at the iliac crest donor site in patients undergoing treatment of fracture nonunion. METHODS: Ninety-two patients undergoing anterior iliac crest bone-grafting for nonunion or delayed union of a long-bone fracture were prospectively enrolled. Twenty-seven patients undergoing an alternative surgical treatment were enrolled as a control group. Questionnaires including pain on a visual analog scale (0 to 10) at the donor site were completed by patients at two weeks, six weeks, three months, and one year postoperatively. Short Form-36 (SF-36) forms were completed at enrollment and at the time of final follow-up. RESULTS: The mean pain on the visual analog scale at the donor site was 3.9 at two weeks but rapidly decreased to 1.4 at six weeks and reached 0.3 at one year or more postoperatively (p<0.001). Only two patients (2%) reported a pain value of >3 at one year or more postoperatively. There were three deep infections (3%) at the donor site, and no patients had a permanent sensory deficit in the lateral femoral cutaneous nerve distribution. At the time of final follow-up (mean, twenty-two months), scores for the SF-36 bodily pain subscale were significantly higher in the iliac crest group than in the control group, indicating a greater improvement in overall bodily pain in the iliac crest group. CONCLUSIONS: Anterior iliac crest bone-grafting for nonunion was a well-tolerated procedure. Substantial, persistent pain at the iliac crest donor site occurred in 2% of patients. Iliac crest bone-grafting did not appear to impair function or well-being compared with alternative treatments.

The use of an algorithm for classifying acetabular fractures: a role for resident education?

BACKGROUND: The Letournel and Judet classification system is commonly used for classifying acetabular fractures. However, for orthopaedic surgeons with less experience with these fractures, correct classification can be more difficult. A stepwise approach has been suggested to enhance the inexperienced observer's ability to properly classify acetabular fractures, but it is unclear whether this actually improves one's ability. QUESTIONS/PURPOSES: We asked (1) whether the use of a step-by-step algorithm improves residents' ability to classify acetabular fractures, (2) whether resident experience influenced ability to correctly classify acetabular fractures, and (3) which acetabular fractures were the most difficult to classify? METHODS: Forty-six residents reviewed 15 sets of plain radiographs of 10 acetabular fracture patterns. Residents used the Letournel and Judet classification with only a diagram for reference. Three weeks later they were asked to classify the fractures a second time with the use of the algorithm. We then compared the number of correct responses from the two sessions and determined whether resident experience and use of the algorithm influenced correct classification. RESULTS: We found an improvement in the number of correctly classified fractures between the first (348/690 [50%]) and second (409/690 [59%]) sessions. Thirty-two of 46 participants improved their score with the use of the algorithm. There was a tendency for participants with more residency training to correctly classify the fractures. CONCLUSIONS: The algorithm provided modest improvement to the residents' ability to classify acetabular fractures. This or other such algorithms could provide residents with a basic tool to better evaluate standard radiographs and classify acetabular fractures.

Radiation therapy for heterotopic ossification prophylaxis acutely after elbow trauma: a prospective randomized study.

BACKGROUND: Heterotopic ossification around the elbow can result in pain, loss of motion, and impaired function. We hypothesized that a single dose of radiation therapy could be administered safely and acutely after elbow trauma, could decrease the number of elbows that would require surgical excision of heterotopic ossification, and might improve clinical results. METHODS: A prospective randomized study was conducted at three medical centers. Patients with an intra-articular distal humeral fracture or a fracture-dislocation of the elbow with proximal radial and/or ulnar fractures were enrolled. Patients were randomized to receive either single-fraction radiation therapy of 700 cGy immediately postoperatively (within seventy-two hours) or nothing (the control group). Clinical and radiographic assessment was performed at six weeks, three months, and six months postoperatively. All adverse events and complications were documented prospectively. RESULTS: This study was terminated prior to completion because of an unacceptably high number of adverse events reported in the treatment group. Data were available on forty-five of the forty-eight patients enrolled in this study. When the rate of complications was investigated, a significant difference was detected in the frequency of nonunion between the groups. Of the nine patients who had a nonunion, eight were in the treatment group. The nonunion rate was 38% (eight) of twenty-one patients in the treatment group, which was significantly different from the rate of 4% (one) of twenty-four patients in the control group (p = 0.007). There were no significant differences between the groups with regard to the prevalence of heterotopic ossification, postoperative range of motion, or Mayo Elbow Performance Score noted at the time of study termination. CONCLUSIONS: This study demonstrated that postoperative single-fraction radiation therapy, when used acutely after elbow trauma for prophylaxis against heterotopic ossification, may play a role in increasing the rate of nonunion at the site of the fracture or an olecranon osteotomy. The clinical efficacy of radiation therapy could not be determined on the basis of the sample size. Further research is needed to determine the role of limited-field radiation for prophylaxis against heterotopic ossification after elbow trauma.

Efficacy of intraoperative red blood cell salvage and autotransfusion in the treatment of acetabular fractures.

OBJECTIVES: To determine if cell saver (CS) use in patients with acetabular fractures reduces the volume or rate of allogeneic blood transfused intraoperatively and postoperatively and if this translated to a decrease in blood-related charges to the patient. DESIGN: Retrospective review. SETTING: Level 1 trauma center. PATIENTS: One hundred eighty-six patients with operatively treated acetabular fractures. INTERVENTION: All patients underwent open reduction internal fixation of their acetabular fracture. The decision to use CS was at the surgeon's discretion. MAIN OUTCOME MEASUREMENTS: The volume and rate of intraoperative and postoperative allogeneic blood transfused and blood-related charges were evaluated. RESULTS: CS was used in 60 cases (32%), and the average volume of blood autotransfused was 345 mL. No differences were observed in the rates (58.3% vs 48%, P = 0.1883) or the mean volumes (770 vs 518 mL, P = 0.0537) of intraoperative and postoperative allogeneic blood transfusions between the CS and the non-CS groups. Total blood-related charges in the CS group were significantly higher than that in the nonCS group ($1958 vs $694, P < 0.0001). Subanalyses based on fracture pattern, injury severity score, body mass index, days to surgery, and estimated blood loss were performed. In each subanalyses, no differences were observed in intraoperative and postoperative transfusion rates and volumes, and total blood-related charges were higher in the CS groups. CONCLUSIONS: In the routine use of CS in acetabular surgery, there was no reduction in the volume or rate of allogeneic blood transfused intraoperatively or postoperatively. However, blood-related charges were significantly increased.

Locked plating of supracondylar periprosthetic femur fractures.

Fifty periprosthetic supracondylar femur fractures above a total knee arthroplasty were reviewed. Fractures were closed Lewis and Rorabeck type II with a stable prosthesis. Twenty-nine patients (group I), were treated with locked condylar plating. Twenty-one patients (group II) were treated with nonlocked plating systems or intramedullary fixation. Minimum follow-up was 1.7 years. There were 5 malunions (20%) in group I and 9 (47%) in group II (P < .05). There were no nonunions in group I and 3 (16%) in group II. Complication rates were 12% in group I, compared to 42% in group II. Group I patients had less operative blood loss, healed in better alignment, and had greater knee motion. All 7 patients treated with a retrograde intramedullary nail developed a malunion or nonunion. Locked plating is a reliable treatment for periprosthetic supracondylar femur fractures. We experienced a lower complication, revision, malunion, and nonunion rate with locked plating versus conventional treatment options.

The insensate foot following severe lower extremity trauma: an indication for amputation?

BACKGROUND: Plantar sensation is considered to be a critical factor in the evaluation of limb-threatening lower extremity trauma. The present study was designed to determine the long-term outcomes following the treatment of severe lower extremity injuries in patients who had had absent plantar sensation at the time of the initial presentation. METHODS: We examined the outcomes for a subset of fifty-five subjects who had had an insensate extremity at the time of presentation. The patients were divided into two groups on the basis of the treatment in the hospital: an insensate amputation group (twenty-six patients) and an insensate salvage group (twenty-nine patients), the latter of which was the group of primary interest. In addition, a control group was constructed from the parent cohort so that the patients in the study groups could be compared with patients in whom plantar sensation was present and in whom the limb was reconstructed. Patient and injury characteristics as well as functional and health-related quality-of-life outcomes at twelve and twenty-four months after the injury were compared between the subjects in the insensate salvage group and those in the other two groups. RESULTS: The patients in the insensate salvage group did not report or demonstrate significantly worse outcomes at twelve or twenty-four months after the injury compared with subjects in the insensate amputation or sensate control groups. Among the patients in whom the limb was salvaged (that is, those in the insensate salvage and sensate control groups), an equal proportion (approximately 55%) had normal plantar sensation at two years after the injury, regardless of whether plantar sensation had been reported to be intact at the time of admission. No significant differences were noted among the three groups with regard to the overall, physical, or psychosocial scores. At two years after the injury, only one patient in the insensate salvage group had absent plantar sensation. CONCLUSIONS: Outcome was not adversely affected by limb salvage, despite the presence of an insensate foot at the time of presentation. More than one-half of the patients who had presented with an insensate foot that was treated with limb reconstruction ultimately regained sensation at two years. Initial plantar sensation is not prognostic of long-term plantar sensory status or functional outcomes and should not be a component of a limb-salvage decision algorithm.

Unstable proximal extraarticular tibia fractures: a biomechanical evaluation of four methods of fixation.

OBJECTIVE: To compare the biomechanical stability of extraarticular proximal tibia fractures reconstructed using a double-plate construct, locking plate system, hybrid external fixator, and single lateral periarticular plate, all from the same manufacturer. DESIGN: Standardized proximal tibial fractures (AO classification 41-A3.2 and A3.3) in synthetic tibiae were stabilized using one of the four constructs. Load versus proximal fragment translation and rotation were monitored in each case. Fixation was evaluated for moderately unstable and completely unstable fractures simulated by wedge and gap osteotomies of the proximal femur. SETTING: Academic medical center biomechanical engineering laboratory. MAIN OUTCOME MEASUREMENTS: Proximal fragment axial displacement, varus rotation, and posterior rotation versus applied load for each of the constructs. RESULTS: The double-plate construct was significantly stiffer than all other constructs with regard to resistance to axial displacement, varus rotation, and posterior rotation for both types of unstable fractures. With regard to axial stiffness, the double-plate construct was statistically similar to an intact tibia for moderately stable fractures. The locking plate and the external fixator were similar for stabilization of moderately unstable fractures, whereas the locking plate and the periarticular plate were significantly stiffer than the external fixator construct for completely unstable fractures. CONCLUSION: For axial load applied to a wedge or gap osteotomy of the proximal tibia, the double-plate construct provided significantly more rigidity than the other constructs. The locking plate, periarticular plate, and hybrid external fixator tested provided similar rigidity for the wedge osteotomy, but for the gap osteotomy the external fixator could not support 600N without complete closure of the gap.

Treatment of complex tibial plateau fractures using the less invasive stabilization system plate: clinical experience and a laboratory comparison with double plating.

BACKGROUND: Bicondylar tibial plateau fractures are complex injuries, historically associated with high complication rates. The purpose of this study was: 1) to evaluate the clinical use L.I.S.S plating system for stabilization of bicondylar tibial plateau fractures. 2) To compare the biomechanics of this plating system with a double plate construct. METHODS AND MATERIALS: Thirty-eight patients who sustained a complex tibial plateau fracture (OTA type 41C) at one of three level-one trauma centers were stabilized using the Less Invasive Stabilization System (L.I.S.S.). The cohort of patients was evaluated clinically and radiographically for outcomes at a mean 15 months. In phase 2 of this study a model of a bicondylar tibial plateau fractures was made in six matched pairs of embalmed, human tibia and randomized to fixation with either a L.I.S.S plate or a standard double plate construct. The tibias were then subjected to an axial cyclic load of 500N for 10 cycles (3Hz) to approximate 2 months in vivo and displacements measured. RESULTS: Thirty-six of /38 (95%) patients united at 4 months after surgery with no loss of fixation nor infection. Two patients underwent prophylactic autogenous bone grafting for bone loss and united by 3 months postgrafting. Significant loss of knee range of motion (<90) was seen in five patients.Biomechanically, no differences in permanent inferior displacement of the medial fragment were found in initial axial loading and after 10 cycles between the two plate constructs. However, when loaded to 500N the L.I.S.S plate construct demonstrated almost twice the displacement of the medial fragment compared with the dual plate construct. No specimen lost fixation during cycling. CONCLUSION: The L.I.S.S plating system provides stable fixation of complex bicondylar tibial plateau fractures allowing early range of knee motion with favorable clinical results.

Prospective comparison of contrast-enhanced computed tomography versus magnetic resonance venography in the detection of occult deep pelvic vein thrombosis in patients with pelvic and acetabular fractures.

OBJECTIVE: To determine the rate of pelvic vein thrombosis following acetabular or pelvic fracture identified by enhanced computed tomography venography or magnetic resonance venography. DESIGN: Prospective evaluation of computed tomography venography and magnetic resonance venography in patients with pelvic and acetabular trauma as a screening tool for deep vein thrombosis. SETTING: Level I trauma center. RESULTS: Thirty patients with pelvic or acetabular fractures and who met the study criteria were prospectively screened with magnetic resonance venography and computed tomography venography to determine preoperative presence of pelvic venous thrombosis. Pelvic deep vein thrombosis was detected by computed tomography venography in two patients (7%) and by magnetic resonance venography in four patients (13%). Invasive selective pelvic venographies were performed on the five subjects who tested positive on either one or both screening tests. Only one computed tomography venography case was validated by invasive pelvic venography. The false-positive rate for computed tomography venography was 50%, and the false-positive rate for magnetic resonance venography was 100%. CONCLUSIONS: We cannot recommend the sole use of either computed tomography venography or magnetic resonance venography to screen and direct the treatment of asymptomatic thrombi in patients with fracture of the pelvic ring because of the high false positive rates. If these studies are used as screening tools, confirmation of the presence of thrombosis with selective venography should be performed prior to initiating invasive treatment with a vena cava filter. Clinical decisions based solely on one of these imaging techniques may result in inappropriate aggressive treatment due to the high false-positive rate.