Theodore T. Manson

Young-burgess Classification of Pelvic Ring Fractures: Does It Predict Mortality, Transfusion Requirements, and Non-orthopaedic Injuries?

Objectives: The objectives of this study were to evaluate the ability of the Young-Burgess classification system to predict mortality, transfusion requirements, and nonorthopaedic injuries in patients with pelvic ring fractures and to determine whether mortality rates after pelvic fractures have changed over time. Design: Retrospective review. Setting: Level I trauma center. Patients: One thousand two hundred forty-eight patients with pelvic fractures during a 7-year period. Intervention: None. Main Outcome Measurements: Mortality at index admission, transfusion requirement during first 24 hours, and presence of nonorthopaedic injuries as a function of Young-Burgess pelvic classification type. Mortality compared with historic controls. Results: Despite a relatively large sample size, the ability of the Young-Burgess system to predict mortality only approached statistical significance (P = 0.07, Kruskal-Wallis). The Young-Burgess system differentiated transfusion requirements-lateral compression Type 3 (LC3) and anteroposterior compression Types 2 (APC2) and 3 (APC3) fractures had higher transfusion requirements than did lateral compression Type 1 (LC1), anteroposterior compression Type 1 (APC1), and vertical shear (VS) (P < 0.05)-but was not as useful at predicting head, chest, or abdomen injuries. Dividing fractures into stable and unstable types allowed the system to predict mortality rates, abdomen injury rates, and transfusion requirements. Overall mortality in the study group was 9.1%, unchanged from original Young-Burgess studies 15 years previously (P = 0.3). Conclusions: The Young-Burgess system is useful for predicting transfusion requirements. For the system to predict mortality or nonorthopaedic injuries, fractures must be divided into stable (APC1, LC1) and unstable (APC2, APC3, LC2, LC3, VS, combined mechanism of injury) types. LC1 injuries are very common and not always benign (overall mortality rate, 8.2%).

Pelvic ring fractures are an independent risk factor for death after blunt trauma.

BACKGROUND It is unknown whether pelvic ring fracture is an independent predictor of death after blunt trauma. Few previous studies have attempted to analyze whether the high death rate observed in association with pelvic ring injury is secondary to the pelvic ring injury or merely related to many other injuries that typically are sustained in such cases. Our hypothesis was that pelvic ring fracture is an independent risk factor for death, even after accounting for the risk of death from other associated injuries. METHODS We reviewed the records of 31,550 patients who presented with blunt trauma at our Level I trauma center from 1995 to 2002. We analyzed our prospectively collected database and excluded any patient who was missing more than one demographic parameter (n = 414, 1.3% of the data set). Our study group consisted of 1,017 patients with pelvic ring fractures and 30,119 patients with blunt trauma without pelvic ring fractures. Multiple logistic regression analysis was conducted to account for the relative contribution of associated clinical criteria to mortality. A mortality model was then designed by using the regression analysis, allowing us to compare a calculated chance of death for each patient in the study group. We then compared the expected number of deaths of patients with pelvic injury with the actual number of observed deaths in that data set. Additionally, we conducted a second statistical analysis with which we compared the death rate of our pelvic ring fracture population (n = 1,017) with a matched subgroup (n = 1,017) from our patient population without pelvic ring fractures (n = 30,119). RESULTS The presence of pelvic ring fracture was found to be an independent risk factor for mortality in the blunt trauma population based on both statistical methods (odds ratios, 1.9 [p < 0.001] and 2.1 [p < 0.0007]). Other significant predictors of mortality included patient age, Injury Severity Score, Glasgow Coma Scale score, systolic blood pressure and respiratory rate at admission, and several medical comorbidities. CONCLUSION The presence of pelvic ring fracture seems to represent a clinically significant independent risk factor for mortality, even after accounting for the association with potentially severe additional body system injuries.

Unicondylar Knee Retrieval Analysis

Unicondylar knee arthroplasty (UKA) is considered an alternative to total knee arthroplasty for patients who have arthritis limited to one compartment of the knee. This study examined surface damage of 3 contemporary UKA designs that were retrieved at revision surgery. Two of the UKA designs were fixed bearing and one was mobile bearing. Demographic information was collected, as well as information about the implants used at revision surgery. Articular surface damage was greater in the fixed-bearing designs as compared to the mobile bearing, although the mobile-bearing implants had significantly shorter length of implantation. Backside damage was also graded for the mobile bearing and when combined with articular wear resulted in overall damage scores higher than both fixed-bearing designs. The fixed-bearing designs showed delamination and surface deformation, whereas the mobile bearing had no evidence of these damage modes. However, mobile-bearing components showed other types of wear, and significant wear damage was present on the bearing surfaces of the mobile-bearing implants despite a short time of implantation. At the time of conversion to a total knee arthroplasty, more than 50% of cases required the use of stems, augments, or constrained inserts for the tibial reconstruction. In conclusion, wear modes differed among UKA prosthesis designs. Revision of a UKA to a total knee arthroplasty remains complex with the tibial preparation more complicated than in the primary setting.

Is time to flap coverage of open tibial fractures an independent predictor of flap-related complications?

Objectives: The importance of the timing of flap coverage of open tibial shaft fractures remains controversial. Many studies have shown increased complications and infection rates associated with delay in coverage but have not controlled for risk factors that might be associated with both delay in coverage and complications. We hypothesized that the timing of flap coverage of open tibial fractures is not predictive of complications after controlling for known risk factors. Design: Retrospective review. Setting: Level I trauma center. Patients: Sixty-nine patients treated for acute tibial fractures (45 tibial shaft, 17 plateau, and 12 pilon fractures) at our center from 2004 through 2009 required 74 flaps. Patients requiring flaps later for wound breakdown or infection were excluded. Intervention: Electronic records and prospective trauma database were reviewed. All fractures were AO classified by a trauma fellowship-trained orthopaedic surgeon. Main Outcome Measurements: Primary outcome was flap complication, defined as infection or other flap-related adverse outcome requiring surgical treatment. Logistic regression analysis was conducted. Results: A logistic regression model that separated the first 7 days after injury from subsequent days found no increased risk for days 1 through 7. The odds of complications, and of infection in particular, increased by 11% and 16%, respectively, for each day beyond day 7 (P < 0.04). Conclusions: Even after controlling for known risk factors for complications, including injury severity, time to flap coverage was a significant predictor of complications. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Building a clinical research network in trauma orthopaedics: The major extremity trauma research consortium (METRC)

Objectives: Lessons learned from battle have been fundamental to advancing the care of injuries that occur in civilian life. Equally important is the need to further refine these advances in civilian practice, so they are available during future conflicts. The Major Extremity Trauma Research Consortium (METRC) was established to address these needs. Methods: METRC is a network of 22 core level I civilian trauma centers and 4 core military treatment centers—with the ability to expand patient recruitment to more than 30 additional satellite trauma centers for the purpose of conducting multicenter research studies relevant to the treatment and outcomes of orthopaedic trauma sustained in the military. Early measures of success of the Consortium pertain to building of an infrastructure to support the network, managing the regulatory process, and enrolling and following patients in multiple studies. Results: METRC has been successful in maintaining the engagement of several leading, high volume, level I trauma centers that form the core of METRC; together they operatively manage 15,432 major fractures annually. METRC is currently funded to conduct 18 prospective studies that address 6 priority areas. The design and implementation of these studies are managed through a single coordinating center. As of December 1, 2015, a total of 4560 participants have been enrolled. Conclusions: Success of METRC to date confirms the potential for civilian and military trauma centers to collaborate on critical research issues and leverage the strength that comes from engaging patients and providers from across multiple centers.

Internal anterior fixators for pelvic ring injuries: Do monaxial pedicle screws provide more stiffness than polyaxial pedicle screws?

OBJECTIVES Little is known about the mechanical properties of internal anterior fixators (known as INFIX), which have been proposed as subcutaneous alternatives to traditional anterior external fixators for pelvic ring disruptions. We hypothesised that INFIX has superior biomechanical performance compared with traditional external fixators because the distance from the bar to the bone is reduced. METHODS Using a commercially available synthetic bone model, 15 unstable pelvic ring injuries were simulated by excising the pubic bone through the bilateral superior and inferior rami anteriorly and the sacrum through the bilateral sacral foramen posteriorly. Three test groups were established: (1) traditional supra-acetabular external fixation, (2) INFIX with polyaxial screws, (3) INFIX with monaxial screws. Load was applied, simulating lateral compression force. Outcome measure was construct stiffness. RESULTS The traditional external fixator constructs had an average stiffness of 6.21 N/mm ± 0.40 standard deviation (SD). INFIX with monaxial screws was 23% stiffer than the traditional external fixator (mean stiffness, 7.66 N/mm ± 0.86 SD; p = .01). INFIX with polyaxial screws was 26% less stiff than INFIX with monaxial screws (mean stiffness, 5.69 N/mm ± 1.24 SD; p = .05). No significant difference was noted between polyaxial INFIX and external fixators (mean stiffness, 6.21 N/mm ± 0.40 SD; p=.65). CONCLUSIONS The performance of INFIX depends on the type of screw used, with monaxial screws providing significantly more stiffness than polyaxial screws. Despite the mechanical advantage of being closer to the bone, polyaxial INFIX was not stiffer than traditional external fixation.

Combined pelvic ring disruption and acetabular fracture: associated injury patterns in 40 patients.

Objectives: Combined pelvic ring disruptions and acetabular fractures are thought to be uncommon. Our objectives were to characterize concomitant injury patterns and to compare them with historically observed rates for each injury in isolation. Design: Retrospective review comparing a study group with historical controls. Fracture patterns were compared with our institutions isolated injury patterns and with isolated injury patterns of other published series. Setting: Level I academic medical center. Patients: Between 1997 and 2001, 854 pelvic ring disruptions and 457 acetabular fractures were evaluated. Forty patients sustained combined injuries. Intervention: None. Main Outcome Measurements: Fracture patterns, Injury Severity Scores, and mortality rates. Results: Our series of combined injuries included 5% posterior wall fractures. This was significantly different from the 30% incidence of posterior wall fractures among isolated acetabular fractures at our institution (P < 0.006). No posterior column or posterior column with associated posterior wall fractures occurred. Fifty-three percent of the patients sustained anterior–posterior compression pelvic ring injuries, exceeding our centers 19% norm for isolated pelvic ring injuries (P < 0.001). For combined injuries, the mean injury severity score was 27.9 and the overall mortality rate was 13%. Early death occurred in 19% of patients with combined anterior–posterior compression injuries and 6% with lateral compression injuries. Conclusions: Patients with combined pelvic and acetabular injuries have multiple system injuries and high Injury Severity Scores. Fracture patterns differ from those observed with isolated injuries. Posterior acetabular fractures are uncommon components. Anterior–posterior compression pelvic injuries seem much more frequent in cases of combined injuries than isolated injuries and are associated with high mortality rates. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Does Fracture Pattern Predict Death With Lateral Compression Type 1 Pelvic Fractures

BACKGROUND Our goal was to analyze whether radiographic fracture pattern correlates with mortality of patients with lateral compression type 1 (LC1) fractures. METHODS We conducted a retrospective case-controlled study at a Level I trauma center. Radiographs and outcome data were obtained for 52 patients with LC1 fractures who died and 63 who lived. LC1 fractures were classified by Denis zone of sacral injury and presence of fracture displacement. Our main outcome measurement was mortality during index hospital admission. RESULTS No difference was observed in frequency of higher energy Denis zone II sacral fractures between patients with LC1 fractures who died (73.1%) and those who lived (69.8%, p = 0.86, χ²). No difference was observed in number of displaced fractures (50.0% vs. 34.9%, p = 0.15, χ²). Patients who died were more likely to have significant brain injury (69.2% vs. 14.2%, p < 0.0001, χ²), chest injury (73.1% vs. 49.2%, p < 0.05, χ²), or abdominal injury (30.8% vs. 9.5%, p < 0.05, χ²) than those who lived. CONCLUSION Sacral fracture pattern does not seem to be predictive of mortality for patients with LC1 pelvic fractures The presence of associated injuries seems to be the key driver of mortality.

Do one-time intracompartmental pressure measurements have a high false-positive rate in diagnosing compartment syndrome?

BACKGROUND Intracompartmental pressure measurements are frequently used in the diagnosis of compartment syndrome, particularly in patients with equivocal or limited physical examination findings. Little clinical work has been done to validate the clinical use of intracompartmental pressures or identify associated false-positive rates. We hypothesized that diagnosis of compartment syndrome based on one-time pressure measurements alone is associated with a high false-positive rate. METHODS Forty-eight consecutive patients with tibial shaft fractures who were not suspected of having compartment syndrome based on physical examinations were prospectively enrolled. Pressure measurements were obtained in all four compartments at a single point in time immediately after induction of anesthesia using a pressure-monitoring device. Preoperative and intraoperative blood pressure measurements were recorded. The same standardized examination was performed by the attending surgeon preoperatively, postoperatively, and during clinical follow-up for 6 months to assess clinical evidence of acute or late compartment syndrome. RESULTS No clinical evidence of compartment syndrome was observed postoperatively or during follow-up until 6 months after injury. Using the accepted criteria of delta P of 30 mm Hg from preoperative diastolic blood pressure, 35% of cases (n = 16; 95% confidence interval, 21.5–48.5%) met criteria for compartment syndrome. Raising the threshold to delta P of 20 mm Hg reduced the false-positive rate to 24% (n = 11; 95% confidence interval, 11.1–34.9%). Twenty-two percent (n = 10; 95% confidence interval, 9.5–32.5%) exceeded absolute pressure of 45 mm Hg. CONCLUSION A 35% false-positive rate was found for the diagnosis of compartment syndrome in patients with tibial shaft fractures who were not thought to have compartment syndrome by using currently accepted criteria for diagnosis based solely on one-time compartment pressure measurements. Our data suggest that reliance on one-time intracompartmental pressure measurements can overestimate the rate of compartment syndrome and raise concern regarding unnecessary fasciotomies. LEVEL OF EVIDENCE Diagnostic study, level II.

Embolization of pelvic arterial injury is a risk factor for deep infection after acetabular fracture surgery.

Objective To determine whether embolization of pelvic arterial injuries before open reduction and internal fixation (ORIF) of acetabular fractures is associated with an increased rate of deep surgical site infection. Methods Retrospective review of patients who underwent ORIF of acetabular fractures at our institution from 1995 through 2007 (n = 1440). We compared patients with acetabular fractures who underwent angiography and embolization of a pelvic artery (n = 12) with those who underwent angiography but did not undergo embolization (n = 14). Primary outcome was presence of infection requiring return to the operating room. Results Seven (58%) of the 12 patients who underwent embolization developed deep surgical site infection compared with only 2 (14%) of the patients who underwent angiography but did not require pelvic vessel embolization (P < 0.05, Fisher exact test). Conclusions The combination of an acetabular fracture that requires ORIF and a pelvic arterial injury that requires angiographic embolization is rare. However, the 58% infection rate of the patients who underwent embolization before ORIF is an order of magnitude higher than typical historical controls (2%–5%) and significantly higher than that of the control group of patients who underwent angiography without embolization (14%). In addition, a disproportionate number of the patients who developed infection had their entire internal iliac artery embolized. Surgeons should be aware that embolization of a pelvic arterial injury is associated with a high rate of infection after subsequent ORIF of an acetabular fracture. Embolization of the entire iliac artery should be avoided whenever possible. Level of Evidence Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.