Robert V. O’Toole

Resuscitation before stabilization of femoral fractures limits acute respiratory distress syndrome in patients with multiple traumatic injuries despite low use of damage control orthopedics.

BACKGROUND Femoral shaft fractures are associated with acute respiratory distress syndrome (ARDS). The idea that primary intramedullary nailing increases the incidence of ARDS has theoretical support. Our approach to treating femoral fractures in patients with multiple traumatic injuries is to perform reamed nailing after adequate resuscitation has been shown by normalizing lactate plus optimized ventilatory and hemodynamic parameters. Damage control orthopedics (DCO) with primary external fixation usually is reserved for those rare patients who do not respond to resuscitation. Our hypothesis was that this approach yields a low rate of ARDS. METHODS A prospective trauma database was searched for all femoral shaft fractures treated at a Level I trauma center during a 3-year period, yielding 582 patients. Exclusion criteria included death before treatment (n = 9), age younger than 16 years (n = 16), age older than 65 years (n = 35), fractures that were not amenable to nail fixation (n = 31), shaft fractures treated with a plate (n = 3), patients with bilateral femoral shaft fractures who had a primary nail placed in one femur and an external fixator on the other limb (n = 1), and patients with an Injury Severity Score (ISS) <or=17 (n = 260), leaving 227 patients in the final study group. We defined ARDS as a mean partial pressure of oxygen/fraction of inspired oxygen <200 for 5 or more consecutive days. We compared our results with the results of a similar design in the literature. RESULTS Of the 227 patients with ISS >17, only 12% were initially treated with DCO, and 88% were treated with primary reamed nailing. The 227 patients achieved successful early resuscitation as shown by lactate values that decreased significantly on the operative day compared with presenting values (p < 0.05). ARDS rates were low, including rates for the subgroup of patients with lung injury (thoracic Abbreviated Injury Scale score >2, n = 175) who were treated with nailing and had an ARDS rate of 2.0% and a death rate of 2.0%. The ARDS rate for the most severely injured patients who underwent nailing (ISS >28, thoracic Abbreviated Injury Scale score >2, n = 78) was only 3.3%, and 1.7% died. CONCLUSIONS In the context of resuscitation before reamed intramedullary nailing of femoral shaft fractures, our rate of ARDS was lower (p < 0.001) than that of a similar study reported in the literature in which the DCO approach was used in up to 36% of patients (p < 0.001) and was more in keeping with previously reported rates of ARDS. This remained true despite frequent use of early reamed femoral nailing and infrequent use of DCO. An explanation for the discrepancy between the centers might be differences in preoperative resuscitation or medical care provided to treat shock.

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.

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.

Fixed angle devices versus multiple cancellous screws: What does the evidence tell us?

Complications, including nonunion and avascular necrosis, are relatively common after internal fixation of a femoral neck fracture. Young patients are particularly impacted by these complications as salvage options often result in a suboptimal functional result. The quality of reduction appears to be of primary importance; however, it is unknown whether the choice of internal fixation affects the incidence of complications. In this article, we present the rationale and evidence for available internal fixation options. Current evidence is insufficient to recommend an optimal method of internal fixation, and this review demonstrates the need for high-quality randomised, controlled trials to study this problem.

Fixation of displaced femoral neck fractures in young adults: Fixed-angle devices or Pauwel screws?

BACKGROUND We sought to compare the incidence of complications after fixation of displaced femoral neck fractures in young adults treated with fixed-angle devices versus multiple cancellous screws and a trochanteric lag screw (Pauwel screw). METHODS We conducted a retrospective cohort study at a level I trauma centre. Sixty-two skeletally mature patients (age range, 16-60 years) with displaced femoral neck fractures were included in the study. Forty-seven were treated with a fixed-angle device (sliding hip plate with screw or helical blade) and 15 with multiple cancellous screws placed in a Pauwel configuration. The main outcome measure was postoperative complication of osteonecrosis or nonunion treated with a surgical procedure. RESULTS Significantly fewer failures occurred in the fixed-angle group (21%) than in the screws group (60%) (p=0.008). Osteonecrosis was rare in the fixed-angle group, occurring in 2% of cases versus 33% of cases in the screws group (p=0.002). Consistent with previous studies, good to excellent reductions were associated with a failure rate of 25% and fair to poor reductions were associated with a failure rate of 55% (p=0.07). The best-case scenario of a good to excellent reduction stabilised with a fixed-angle device yielded a success rate of 85%. CONCLUSION In young patients with displaced high-energy femoral neck fractures, fixed-angle devices resulted in fewer treatment failures than did Pauwel screws.

Does Surgical Stabilization of Lateral Compression-type Pelvic Ring Fractures Decrease Patients’ Pain, Reduce Narcotic Use, and Improve Mobilization?

BackgroundDebate remains over the role of surgical treatment in minimally displaced lateral compression (Young-Burgess, LC, OTA 61-B1/B2) pelvic ring injuries. Lateral compression type 1 (LC1) injuries are defined by an impaction fracture at the sacrum; type 2 (LC2) are defined by a fracture that extends through the posterior iliac wing at the level of the sacroiliac joint. Some believe that operative stabilization of these fractures limits pain and eases mobilization, but to our knowledge there are few controlled studies on the topic.Questions/purposes(1) Does operative stabilization of LC1 and LC2 pelvic fractures decrease patients’ narcotic use and lower their visual analog scale pain scores? (2) Does stabilization allow patients to mobilize earlier with physical therapy?MethodsThis retrospective study of LC1 and LC2 fractures evaluated patients treated definitively at one institution from 2007 to 2013. All patients treated surgically, all nonoperative LC2, and all nonoperative LC1 fractures with complete sacral injury were included. In general, LC1 or LC2 fractures with greater than 10 mm of displacement and/or sagittal/axial plane deformity on static radiographs were treated surgically. One hundred fifty-eight patients in the LC1 group (107 [of 697 screened] nonoperative, 51 surgical) and 123 patients in the LC2 group (78 nonoperative, 45 surgical) met inclusion criteria. The surgical and nonoperative groups were matched for fracture type. To account for differences between patients treated surgically and nonoperatively, we used propensity modeling techniques incorporating treatment predictors. Propensity scores demonstrated good overlap and were used as part of multiple variable regression models to account for selection bias between the surgically treated and nonoperative groups. Patient-reported pain scores and narcotic administration were tallied in 24-hour increments during the first 24 hours of hospitalization, at 48 hours after intervention, and in the 24 hours before discharge. Time from intervention to mobilization out of bed was recorded; intervention was defined as the date of definitive surgical intervention or the day the surgeon determined the patient would be treated without surgery.ResultsThere was no difference in the narcotics distributed to any of the groups with the exception that the patients with surgically treated LC2 fractures used, on average (mean [95% confidence interval]) 40.2 (−72.9 to −7.6) mg morphine less at the 48-hour mark (p = 0.016). In general, there were no differences between the groups’ pain scores. The surgically treated patients with LC1 fractures mobilized 1.7 (−3.3 to −0.01) days earlier (p = 0.034) than their nonoperative counterparts. There was no difference in the LC2 cohort in terms of time to mobilization between those treated with and without surgery.ConclusionsThere were few differences in pain scores and morphine use between the surgical and nonoperative groups, and the differences observed likely were not clinically important. We found no evidence that surgical stabilization of certain LC1 and LC2 pelvic fractures improves patients’ pain, decreases their narcotic use, and improves time to mobilization. A randomized trial of patients with similar fractures and similar degrees initial displacement would help remove some of the confounders present in this study.Level of EvidenceLevel III, therapeutic study.

Can intramuscular glucose levels diagnose compartment syndrome

BACKGROUND Compartment syndrome is difficult to diagnose, particularly in patients who are not able to undergo adequate clinical examination. Current methods rely on pressure measurements within the compartment, have high false-positive rates, and do not reliably indicate presence of muscle ischemia. We hypothesized that measurement of intramuscular glucose and oxygen can identify compartment syndrome with high sensitivity and specificity. METHODS Compartment syndrome was created in 12 anesthetized adult mixed-sex beagles, in the craniolateral compartment of a lower leg, by infusion of lactated Ringer’s solution with normal serum concentration of glucose. The contralateral leg served as a control. Hydrostatic pressure, oxygen tension, and glucose concentration were recorded with commercially available probes. Compartment syndrome was maintained for 8 hours, and the animals were recovered. Two weeks later, compartment and control legs underwent muscle biopsy. Specimens were reviewed by a blinded pathologist. RESULTS Within 15 minutes of creating compartment syndrome, glucose concentration and oxygen tension in the experimental limb were significantly lower than in the control limb (glucose, p = 0.02; oxygen, p = 0.007; two-tailed t test). Intramuscular glucose concentration of less than 97 mg/dL was 100% sensitive (95% confidence interval [CI], 73–100%) and 75% specific (95% CI, 40–94%) for the presence of compartment syndrome. Partial pressure of oxygen less than 30 mm Hg was 100% sensitive (95% CI, 72–100%) and 100% specific (95% CI, 69–100%) for the presence of compartment syndrome. Pathology confirmed compartment syndrome in all experimental limbs. CONCLUSION Our results show that intramuscular glucose concentration and partial pressure of oxygen rapidly identify muscle ischemia with high sensitivity and specificity after experimentally created compartment syndrome in this animal model.

Surgical site infection in tibial plateau fractures with ipsilateral compartment syndrome

AIM The aim of this study was to investigate the effects of compartment syndrome and timing of fasciotomy wound closure on surgical site infection (SSI) after surgical fixation of tibial plateau fractures. Our primary hypothesis was that SSI rate is increased for fractures with compartment syndrome versus those without, even accounting for confounders associated with infection. Our secondary hypothesis was that infection rates are unrelated to timing of fasciotomy closure or fixation. MATERIALS AND METHODS We conducted a retrospective cohort study of operative tibial plateau fractures with ipsilateral compartment syndrome (n=71) treated with fasciotomy at our level I trauma center from 2003 through 2011. A control group consisted of 602 patients with 625 operatively treated tibial plateau fractures without diagnosis of compartment syndrome. The primary outcome measure was deep SSI after ORIF. RESULTS Fractures with compartment syndrome had a higher rate of SSI (25% versus 8%, p<0.001). The difference remained significant in our multivariate model (odds ratio, 7.27; 95% confidence interval, 3.8-13.9). Delay in timing of fasciotomy closure was associated with a 7% increase per day in odds of infection (95% confidence interval, 0.2-13; p<0.05). CONCLUSIONS Tibial plateau fractures with ipsilateral compartment syndrome have a significant increase in rates of SSI compared with those without compartment syndrome (p<0.001). Delays in fasciotomy wound closure were also associated with increased odds of SSI (p<0.05).

Can applied external fixators be sterilized for surgery? A prospective cohort study of orthopaedic trauma patients

BACKGROUND Temporary external fixators are often used to stabilize fractures when definitive fracture surgery must be delayed. Sometimes, external fixators are left in place during repeat operations, including definitive internal fixation of tibial pilon and tibial plateau fractures. It is unknown how well current surgical preparation sterilizes these devices, which become part of the surgical field. Our hypothesis was that our institutions standard surgical preparation creates a low rate of culture-positive environments on external fixators at the time of surgical skin incision. METHODS We prospectively consented and enrolled patients to obtain cultures (48 patients, 55 external fixators, 165 sets of culture data). After standard preparation and immediately before incision, cultures were obtained from three sites on each external fixator: 1) most distal pin 1cm from pin-skin interface, 2) most distal bar at midpoint between pin and clamp connectors, and 3) most distal clamp at bar-clamp interface. Our standard preparation for patients with external fixation in place is to don sterile gloves and wipe down all components of the external fixator with 70% alcohol-soaked sterile 4×4in gauze sponges before skin preparation. The skin and external fixator are then prepped in the usual fashion with ChloraPrep for closed wounds or with povidone iodine scrub and paint for open wounds. Swabs were processed and organisms from cultures identified. Clinicians were blinded to study results until study completion. RESULTS Two of 165 cultures (1.2%; 95% confidence interval [CI]: 0-2.9%) were positive for common pathogens sometimes observed in surgical site infection. Four cultures (2.4%; 95% CI: 0-4.8%) had pathogens that are rarely associated with surgical site infection, and four (2.4%; 95% CI: 0-4.8%) had nonpathogenic organisms. CONCLUSION Using 70% alcohol on external fixators plus either ChloraPrep for closed wounds or povidone iodine for open wounds seems to result in a low rate of positive cultures. Most species that were isolated are infrequently identified as sources of surgical site infections. This preparation protocol might be effective at producing a relatively clean environment at the time of surgery for patients with external fixators already in place.

Estimation of tibial shaft defect volume using standard radiographs: development and validation of a novel technique.

BACKGROUND No simple clinical technique with which to measure the volume of bone gaps in the treatment of open fractures or nonunions of the tibia is currently available. It is difficult to compare the three-dimensional magnitude of bone defects in research studies on bone grafting without such a tool, and clinicians have no way of determining the magnitude of defects in clinical practice. The purposes of this study were to develop and to validate a technique with which to accurately measure bone gap volumes of the tibial shaft by using only simple measurements on already available clinical radiographs and a simple equation. We hypothesized that a technique could be developed using anteroposterior- and lateral-view radiographs of the tibia to accurately determine the volume of a tibial shaft fracture. METHODS We created standardized fracture gap models using 45 synthetic tibiae cut in different locations and orientations, rendering 135 gaps. We developed and validated a hydrostatic suspension technique to determine the volume of each bone, which underwent anteroposterior- and lateral-view radiography after each cut. Radiographic measurements were used to calculate defect volumes based on a simple equation. Predicted volumes were compared with measured volumes. RESULTS The triangular prism equation matched well with the actual volumes. Linear regression analysis showed a slope of 0.92 and R(2) of 0.97. CONCLUSION The equation provides a simple technique with which to calculate three-dimensional gap volumes based on standard radiographs. The simplicity of the equation and availability of standard radiographs make this a practical research and perhaps clinical tool that might be useful in quantifying volumes of the tibial shaft defect.