Intramedullary pressure and bone marrow fat intravasation in unreamed femoral nailing

Does the Level and Complexity of Femur Fracture Determine Intramedullary Peak Pressures During Reamed Femoral Nailing? A Prospective Study

OBJECTIVES

To investigate femoral intramedullary (IM) pressures during reamed antegrade nailing and to determine whether fracture level and/or complexity affect peak pressures.

METHODS

DESIGN

Prospective, nonrandomized observational cohort.

SETTING

Single level I trauma center.

PATIENT SELECTION CRITERIA

Patients presenting with femur fractures (OTA/AO 31A3; 32A; 32B; 32C; 33A2; 33A3), requiring antegrade IM nail fixation, were included in this study. Excluded were minors and patients presenting with hemodynamic instability, a reduced level of consciousness and intoxication. Femurs were divided into thirds based on preoperative radiological measurements and allocated to 3 groups based on fracture location: Proximal (A), middle (B), and distal (C) third femur fractures. Fracture complexity was also documented.

OUTCOME MEASURES AND COMPARISONS

Peak IM pressures of proximal, middle, and distal third femoral fractures were compared during antegrade femoral IM nail fixation.

RESULTS

Twenty-two fractures in 21 patients were enrolled and treated over a 4-month period with a distribution of fracture locations of group A = 12, group B = 6, and group C = 4. Measured mean resting distal IM pressures were significantly higher ( P < 0.05) in proximal fractures (group A: 52.5 mm Hg) than in middle and distal third fractures (group B: 36.6 mm Hg and group C: 27.5 mm Hg). Greatest peak pressures were generated during the first ream in groups A and B, occurring distal to the fracture in all cases. Group A averaged 363.8 mm Hg (300-420), group B 174.2 mm Hg (160-200), and group C 98.8 mm Hg (90-100). There was a significant difference comparing group A with B and C combined ( P < 0.01) and group A with B ( P < 0.05) and C ( P < 0.05]) individually. Group A consisted of 6 comminuted and 6 simple fracture configurations. Mean peak pressures in these subgroups differed significantly: 329 mm Hg (300-370) versus 398 mm Hg (370-430), respectively ( P < 0.05). Complex fractures in study groups B and C did not have significantly different peak pressures compared with simple fractures ( P > 0.05).

CONCLUSIONS

Both the fracture location and comminution affect peak IM pressures during reamed antegrade femoral nailing. Proximal, simple fracture configurations resulted in significantly higher pressures when compared with more distal and comminuted fracture configurations.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Severe Hemodynamic Collapse During Humerus Stabilization with Photodynamic Implant: A Report of Two Cases

CASE

We present 2 cases of severe hemodynamic collapse during prophylactic stabilization of impending pathologic humerus fractures using a photodynamic bone stabilization device. Both events occurred when the monomer was infused under pressure into a balloon catheter.

CONCLUSION

We suspect that an increase in intramedullary pressure during balloon expansion may cause adverse systemic effects similar to fat embolism or bone cement implantation syndrome. Appropriate communication with the anesthesia team, invasive hemodynamic monitoring, and prophylactic vent hole creation may help mitigate or manage these adverse systemic effects.

Safety and Efficacy of a Single-Stage versus Two-Stage Intramedullary Nailing for Synchronous Impending or Pathologic Fractures of Bilateral Femur for Oncologic Indications: A Systematic Review

Although intramedullary nail (IMN) fixation is the standard of care for most impending and/or complete pathologic fractures of the femur, the optimal timing/sequence of the IMN in cases of synchronous bilateral femoral disease in advanced cancer is not well established. Thus, we compared the outcomes of single-stage (SS) vs. two-stage (TS) IMN of the bilateral femur with a systematic review of the literature on this topic. Bilateral SS and TS IMN cases were identified from 14 studies extracted from four databases according to PRISMA guidelines. Safety (complications, reoperations, mortality, survival, blood loss, and transfusion) and efficacy (length of stay [LOS], time to start rehabilitation and adjuvant therapy, functional scores, and cost) were compared between the groups. A total of 156 IMNs in 78 patients (36 SS and 42 TS) were analyzed. There were one surgical (infection in TS requiring reoperation; p = 0.860) and fifteen medical complications (five in SS, ten in TS; p = 0.045), with SS being associated with lower rates of total and medical complications. Survival, intraoperative mortality, and postoperative same-admission mortality were similar. No cases of implant failure were reported. Data on LOS, rehabilitation, and adjuvant therapy were scarcely reported, although one study favored SS over TS. No study compared cost or functional scores. Our study is the largest and most comprehensive of its kind in supporting the safety and efficacy of a SS bilateral femur IMN approach in these select patients. Further investigations with higher levels of evidence are warranted to optimize treatment protocols for this clinical scenario.

Intramedullary nailing of concurrent ipsilateral fractures of the tibia and femur: primary synchronous nailing versus staged osteosynthesis with temporizing external fixation

INTRODUCTION

The optimal timing to definitive osteosynthesis in the polytraumatized patient remains an unanswered question. Early total care, damage control orthopaedics, and early appropriate care have been described to manage the fractures in these patients, but there is a paucity of literature specific to ipsilateral tibial and femoral fractures. We sought the perioperative outcomes of primary simultaneous intramedullary nailing (IMN) versus temporizing external fixation (EF) of both fractures.

METHODS

A chart review of all patients who sustained fractures of the ipsilateral femur and tibia that were definitively treated with (IMN) from January 2010 to December 2020 was performed. Patients who underwent initial EF and those that were primarily treated with IMNs were examined.

RESULTS

IMNs and EF were the initial treatment in 23 and 16 patients, respectively. The mean (range) injury severity score (ISS) was 23.3 (33) in the EF group vs. 18.5 (34) in the IMN group, (p = 0.0686). The EF group had a higher total transfused units of packed red blood cells 7.4 vs. 2.8, the mean initial operative time was 236 vs. 282.6 (min), (p = 0.7399), a longer mean total operative time 601.78 vs. 236 (min), and longer mean length of stay 15.6 vs. 11 (days), (p < 0.5). Rates of complications were not significantly different between groups.

CONCLUSION

Primary IMN is as safe as provisional EF in the adequately resuscitated patient with ipsilateral femoral and tibial fractures. This implies the fixation of both fractures into a single surgery without increasing perioperative complications, and decreasing total hospital stay in patients with sufficient preoperative resuscitation.

Fat Embolism Syndrome - A Qualitative Review of its Incidence, Presentation, Pathogenesis and Management

Fat Embolism Syndrome (FES) is a poorly defined clinical phenomenon which has been attributed to fat emboli entering the circulation. It is common, and its clinical presentation may be either subtle or dramatic and life threatening. This is a review of the history, causes, pathophysiology, presentation, diagnosis and management of FES. FES mostly occurs secondary to orthopaedic trauma; it is less frequently associated with other traumatic and atraumatic conditions. There is no single test for diagnosing FES. Diagnosis of FES is often missed due to its subclinical presentation and/or confounding injuries in more severely injured patients. FES is most frequently diagnosed using the Gurd and Wilson criteria, like its rivals it is not clinically validated. Although FES is a multi-system condition, its effects in the lung, brain, cardiovascular system and skin cause most morbidity. FES is mostly a self-limiting condition and treatment is supportive in nature. Many treatments have been trialled, most notably corticosteroids and heparin, however no validated treatment has been established.

Intramedullary Nail Fixation for the Treatment of Pathologic Humeral Shaft Fractures

The goal of this study was to report the clinical outcomes of pathologic humeral shaft fractures treated with reamed or unreamed intramedullary nail fixation in an era of longer patient survival. A retrospective review was conducted of all patients who underwent intramedullary nail fixation performed by a single surgeon for pathologic humeral shaft fractures at a Level I trauma center from 2009 to 2017. Of the 25 patients who were identified, 9 were excluded. Groups were categorized according to whether they underwent reamed or unreamed fixation, and they were evaluated for evidence of union, complications, and reoperation. Of the patients, 11 underwent an unreamed procedure and 5 underwent a reamed procedure. Mean length of follow-up was 51.5 weeks. Of the patients who participated, 12 (75%) showed evidence of union and 2 patients (12.5%) showed evidence of nonunion, with no statistical difference between the groups. Five patients (31.3%) had complications. One nonunion occurred in the reamed group and did not require reoperation. In the unreamed group, complications consisted of 1 delayed union, 1 nonunion treated with revision intramedullary nail fixation, and 2 cases of disease progression that required reoperation. Intramedullary nail fixation of pathologic humeral shaft fractures achieves rates of union parallel to those seen with fixation in a healthy population. The length of follow-up in the current study was longer than the life expectancy reported by previous authors, which can be attributed to improvements in the treatment of cancer. The current authors argue that unreamed fixation is the optimal technique because it yields similar outcomes to a reamed approach and is faster and potentially safer. [Orthopedics. 2020;43(5):e389-e398.].

Fat embolism syndrome in blunt trauma patients with extremity fractures

OBJECTIVE

This study sought to provide a national, descriptive analysis to determine fat embolism syndrome (FES) risk factors, hypothesizing that femur fractures and multiple fractures are associated with an increased risk.

METHODS

The Trauma Quality Improvement Program was queried (2010-2016) for patients with extremity fractures. A multivariable logistic regression analysis model was used.

RESULTS

From 324,165 patients, 116 patients (0.04%) were diagnosed with FES. An age ≤30, closed femur fracture, and multiple long bone fractures were associated with an increased risk of FES.

CONCLUSION

Future research to validate these findings and develop a clinical risk stratification tool appears warranted.

Femoral Derotational Osteotomy Using a Modified Intramedullary Nail Technique

When persistent rotation of the femur remains into adolescence, it can cause functional limitations such as fatigue, anterior knee pain, and frequent tripping. In these cases, derotation of the femur via osteotomy is often performed. We report preliminary results of bilateral derotational osteotomy for excessive femoral anteversion or retroversion using the modified intramedullary nail technique. A retrospective review of 8 patients was performed. Patients were excluded if additional procedures were performed or if the femoral osteotomy included any deformity correction other than rotation. Each patient had simultaneous bilateral femoral osteotomies for a total of 16 limb segments to review. The average age was 12 years, with 4 boys and 4 girls in the group. Seven patients had a preoperative diagnosis of femoral anteversion, and 1 had femoral retroversion. Average amount of derotation performed averaged 30 degrees. Average length of follow-up was 10 months (range, 9 to 12 mo). Average surgical time to complete the bilateral ostetomies was 139 minutes with an average total blood loss of 106 mL. The patients returned to full weight bearing with assistance at 13.75±1.39 days, without assistance at 37.12±5.69 days, and demonstrated full radiographic healing of the femur at 76.13±20.92 days. A modified intramedullary nail technique provides a biologically sound method for rapid healing of the femoral osteotomy site by providing autograft directly to a stable osteotomy site with minimal disruption of the surrounding soft tissue envelope, resulting in faster healing and a quicker return to full, unassisted weight bearing.

Inflammatory response after nailing

Intramedullary nailing, as the gold standard stabilisation method of most long bones, has been tailed by its extensive use as the basic tool of investigating the immune response to trauma in many large and small animal models, as well as at the clinical setting. Over the last few decades a complex map of interactions between pro and anti-inflammatory pathways has been the result of these significant global research efforts. Parallel to the evolution of modern nailing and reaming techniques, significant developments at the fields of other disciplines relevant to trauma care, has improved the contemporary management of injured patients, challenging previous concepts and altering clinical barriers. The current article aims to summarise the current understanding of the effect of instrumenting the medullary canal after trauma, and hint on potential future directions.

Prospective Randomized Clinical Trial Investigating the Effect of the Reamer-Irrigator-Aspirator on the Volume of Embolic Load and Respiratory Function During Intramedullary Nailing of Femoral Shaft Fractures

OBJECTIVES

We sought to determine whether the use of the Reamer-Irrigator-Aspirator (RIA) device resulted in a decreased amount of fat emboli compared with standard reaming (SR) when performing intramedullary (IM) nailing of femoral shaft fractures.

DESIGN

Prospective randomized clinical trial.

SETTING

Multi-centered trial, level I trauma centers.

PATIENTS/PARTICIPANTS

All eligible patients who presented to participating institutions with an isolated femoral shaft fracture amenable to fixation with antegrade IM nailing. Thirty-one patients were enrolled: nine were excluded because of technical difficulties with the transesophageal echocardiogram (TEE) recording. Therefore, the study comprised 22 patients: 11 patients randomized to the SR group and eleven patients randomized to the RIA group.

INTERVENTION

Antegrade IM nailing of a femoral shaft fracture with standard reamers or the RIA device. All patients were monitored intraoperatively with a continuous TEE to assess embolic events in the right atrium. A radial arterial line was used to monitor blood gases and potential systemic effects of emboli.

MAIN OUTCOME MEASURE

Duration, size, and severity of emboli as measured by TEE. The operative procedure was divided into 6 distinct stages: preoperative, reduction, guidewire passage, reaming, nail insertion, and postoperative.

RESULTS

There was no significant difference in emboli between the RIA and SR groups preoperatively, during fracture reduction, guidewire insertion, or postoperatively. Measured with a standardized scoring system, there was a modest reduction in total emboli score in the RIA group during reaming (SR 5.30 [SD; 1.81] vs. RIA 4.05 [SD; 2.19], P = 0.005) and during nail insertion (SR 5.09 [SD; 1.74] vs. RIA 4.25 [SD; 1.89], P = 0.03). We were unable to correlate this reduction with any improvement in physiologic parameters (mean arterial pressure, end-tidal CO2, O2 saturation, pH, paO2, and paCO2).

CONCLUSIONS

This study showed a modest reduction of embolic debris during the reaming and nail insertion segments of the operative procedure. We were unable to correlate this with any change in physiologic parameters.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Reamed versus unreamed intramedullary nailing for the treatment of femoral fractures: A meta-analysis of prospective randomized controlled trials

BACKGROUND AND OBJECTIVE

Intramedullary nailing is commonly used for treating femoral shaft fractures, one of the most common long bone fractures in adults. The reamed intramedullary nail is considered the standard implant for femoral fractures. This meta-analysis was performed to verify the superiority of reamed intramedullary nailing over unreamed intramedullary nailing in fractures of the femoral shaft in adults. Subgroup analysis of implant failure and secondary procedure was also performed.

METHODS

Electronic literature databases were used to identify relevant publications and included MEDLINE (Ovid interface), EMBASE (Ovid interface), and the Cochrane Central Register of Controlled Trials (CENTRAL; Wiley Online Library). The versions available on January 30, 2016, were utilized. Only human studies, which were designed as randomized controlled clinical trials, were included. Two authors independently evaluated the quality of original research publications and extracted data from the studies that met the criteria.

RESULTS

Around 8 randomized controlled trials involving 1078 patients were included. Reamed intramedullary nailing was associated with shorter time to consolidation of the fracture (SMD = -0.62, 95% CI = -0.89 to -0.35, P < 0.00001), lower secondary procedure rate (OR = 0.25, 95% CI 0.10-0.62, P = 0.003), lower nonunion rate (OR = 0.14, 95% CI = 0.05-0.40, P < 0.01), and lower delayed-union rate (OR = 0.19, 95% CI = 0.07-0.49, P < 0.01) compared to unreamed intramedullary nailing. The 2 groups showed no significant differences in risk of implant failure (OR = 0.50, 95% CI 0.14-1.74, P = 0.27), mortality risk (OR = 0.94, 95% CI 0.19-4.68, P = 0.94), risk of acute respiratory distress syndrome (ARDS; OR = 1.55, 95% CI 0.36-6.57, P = 0.55), or blood loss (SMD = 0.57, 95% CI = -0.22 to 1.36, P = 0.15).

CONCLUSION

Reamed intramedullary nailing is correlated with shorter time to union and lower rates of delayed-union, nonunion, and reoperation. Reamed intramedullary nailing did not increase blood loss or the rates of ARDS, implant failure, and mortality compared to unreamed intramedullary nailing. Therefore, the treatment of femoral fractures using reamed intramedullary nailing is recommended.

A meta-analysis of reamed versus unreamed intramedullary nailing for the treatment of closed tibial fractures

Controversy exists regarding the clinical outcomes of reamed vs unreamed intramedullary nailing in the treatment of closed tibial fractures. This study assessed the effects of reamed vs unreamed intramedullary nailing for closed tibial fractures. The authors searched PubMed, EMBASE, BIOSIS, and the Cochrane Controlled Trials Register for randomized and quasi-randomized controlled clinical trials from January 1980 to June 2012 comparing reamed with unreamed intramedullary nailing for closed tibial fracture in adults. Primary outcomes were nonunion, delayed union, malunion, secondary procedure, failure of implants, compartment syndrome, infection, and knee pain. Eight randomized and 1 quasi-randomized clinical trials (1229 fractures) were included. No statistically significant differences were found between reamed and unreamed nailing groups in delayed union (P=.20), malunion (P=.28), infection (P=.36), compartment syndrome (P=.36), and knee pain (P=.93). The unreamed group had a higher rate of fracture nonunion than the reamed group (P=.02). The subgroup analysis of implant failures (broken screws vs broken nails) indicated that reamed nailing significantly reduced the risk of screw breakage (P<.001); however, there was no significant difference between reamed and unreamed intramedullary nailing in nail breakage (P=.94). The subgroup analysis of a secondary procedure showed that the reamed intramedullary nailing resulted in significantly lower risks of implant exchange (P=.01) and dynamization (P=.04); however, there was no significant difference in bone grafting rate (P=.73). Evidence comparing reamed with unreamed intramedullary nailing for closed tibial fractures indicates that reamed intramedullary nailing may lead to significantly lower risks of nonunion, screw failure, implant exchange, and dynamization without increasing operative complications.

The effect of patient position during trauma surgery on fat embolism syndrome: An experimental study

BACKGROUND

The aim of this study was to compare the effect of supine versus lateral position on clinical signs of fat embolism during orthopedic trauma surgery. Dogs served as the current study model, which could be extended and/or serve as a basis for future in vivo studies on humans. It was hypothesized that there would be an effect of position on clinical signs of fat embolism syndrome in a dog model.

MATERIALS AND METHODS

12 dogs were assigned to supine (n = 6) and lateral (n = 6) position groups. Airway pressures, heart rate, blood pressure, cardiac output, pulmonary artery pressure, pulmonary artery wedge pressure, right atrial pressure, arterial and venous blood gases, white blood count, platelet count and neutrophil count were obtained. Dogs were then subjected to pulmonary contusion in three areas of one lung. Fat embolism was generated by reaming one femur and tibia, followed by pressurization of the canal.

RESULTS

No difference was found in any parameters measured between supine and lateral positions at any time (0.126 < P < 0.856).

CONCLUSIONS

The position of trauma patients undergoing reamed intramedullary nailing did not alter the presentation of the features of the lung secondary to fat embolism.

Use of the reamer-irrigator-aspirator may reduce tumor dissemination during intramedullary fixation of malignancies

Intramedullary nail fixation is the treatment of choice for impending and pathologic fractures secondary to metastatic cancer; however, this procedure has been shown to cause systemic embolization of intramedullary contents. This article reports the use of the reamer-irrigator-aspirator (RIA) (Synthes, Paoli, Pennsylvania) instead of a standard femoral reamer to decrease tumor intravasation during femoral intramedullary nail fixation for impending or pathologic fractures.Twenty-one consecutive patients indicated for fixation of malignant femoral lesions were treated with intramedullary nail placement. The RIA was used for canal preparation, and solid reamings were collected and submitted for analysis by a single pathologist. The volume of each specimen was recorded, and representative samples were examined histologically to determine their percent tumor content. These data were then used to estimate the volume of tumor retrieved by the RIA in each case. The mean volume of reamings collected by the RIA was 75.0 cc per case (range, 23.4-196.0 cc), and the mean tumor content was 24.8% (range, 1.0%-60.0%). The mean estimated volume of tumor retrieved in each case was 16.7 cc (range, 0.35-36.0 cc). In 2 cases, the tip of the RIA dissociated from the device intraoperatively but was retrieved without adverse consequence to the patient. Use of the RIA in cases of femoral intramedullary nail fixation for pathologic lesions or fractures effectively retrieves variable amounts of intramedullary contents, including tumor. By preventing the systemic dissemination of malignant cells, this technique may reduce the risk of distant metastases.

Cerebral fat embolism without intracardiac shunt: A novel presentation

Fat embolism syndrome (FES) is defined as an uncommon life-threatening disease process consisting of pulmonary, central nervous system (CNS), and cutaneous manifestations. The pathophysiology of this secondary injury is poorly understood. In the setting of the multiply injured patient, the diagnosis of FES is difficult to ascertain. A case report of a posttraumatic death caused by acute dissemination of diffuse fat emboli to the brain and lungs in the absence of a right-to-left heart defect after femur fracture is presented. The transesophageal echo cardiogram with bubble study failed to demonstrate an intracardiac defect or AV malformation in the lung further supporting a biochemical process. The acute decompensation of the patient within 2 h of the injury would favor mechanical emboli. Supportive care continues to be the mainstay of treatment for FES. Cerebral fat embolism should be considered in traumatically injured patients with unexplained decline in their neurologic examination. Cerebral fat embolism may occur without an intracardiac shunt.

Incidence of pulmonary fat embolism at autopsy: an undiagnosed epidemic

BACKGROUND

To determine the incidence, time course, and severity of pulmonary fat embolism (PFE) and cerebral fat embolism (CFE) in trauma and nontrauma patients at the time of autopsy.

METHODS

Prospectively, consecutive patients presenting for autopsy were evaluated for evidence pulmonary and brain fat embolism. The lung sections were obtained from the upper and lower lobe of the patients' lungs on the right and left and brain tissue. This tissue was prepared with osmium tetroxide for histologic evaluation. The number of fat droplets per high power field was counted for all sections. The autopsy reports and medical records were used to determine cause of death, time to death, injuries, if cardiopulmonary resuscitation (CPR) was attempted, sex, height, weight, and age.

RESULTS

Fifty decedents were evaluated for PFE and CFE. The average age was 45.8 years ± 17.4 years, average body mass index was 30.1 kg/cm² ± 7.0 kg/cm², and 68% of the patients were men. The cause of death was determined to be trauma in 68% (34/50) of decedents, with 88% (30/34) blunt and 12% (4/34) penetrating. CPR was performed on 30% (15/50), and PFE was present in 76% (38/50) of all patients. Subjects with PFE had no difference with respect to sex, trauma, mechanism of injury, CPR, external contusions, fractures, head, spine, chest, abdominal, pelvic, and extremity injuries. However, subjects without PFE had significantly increased weight (109 ± 29 kg vs. 86 ± 18 kg; p = 0.023) but no difference in height or body mass index. PFE was present in 82% (28/34) of trauma patents and 63% (10/16) nontrauma patients. Eighty-eight percent of nontrauma patients and 86% of trauma patients who received CPR had PFE. Trauma patients with PFE showed no significant difference in any group. Eighty-eight percent of trauma patients died within 1 hour of injury, and 80% (24/30) of them had PFE at the time of autopsy. CFE was present only in one patient with a severe head and cervical spine injury.

CONCLUSION

PFE is common in trauma patients. CPR is associated with a high incidence of PFE regardless of cause of death. PFE occurs acutely within the "golden hour" and should be considered in traumatically injured patients. Further studies are needed to evaluate the pathogenesis of PFE.

Unreamed or RIA reamed nailing: an experimental sheep study using comparative histological assessment of affected bone tissue in an acute fracture model

The purpose of the present study was to evaluate the Reamer/Irrigator/Aspirator (RIA), a reaming system designed to incorporate the advantages of irrigation and suction for every day clinical use. The evaluation process was focused on the displacement of the medullary content and its impact on cortical perfusion. The results of the RIA reamed nailing were compared to conventional non-reamed nailing (NRN). The tibia of the sheep was used as an acute fracture model. The fracture and nailing procedure was followed by intravital staining with Procion red. The effects on cortical perfusion (Procion red staining) were addressed in polymer embedded sections and cryosections. Sudan III stained cryosections were evaluated with respect to the cortical fat distribution. After irrigation and suction minute amounts of fat were observed in the cortex, whereas after non-reamed nailing the endosteal third of the cortical bone was penetrated with fat. Non-reamed nailing acutely showed better perfusion in the endosteal tenth and periosteal third of the cortical bone, after irrigation and suction reaming perfusion was preserved to a lesser degree. Irrigation and suction significantly reduces fat intravasation, and thus the danger of system-wide damage. Therefore, the Reamer/Irrigator/Aspirator is as efficient as its experimental predecessors.

Comparison of RIA and conventional reamed nailing for treatment of femur shaft fractures

INTRODUCTION

The standard of care for femoral diaphysis fractures is sequentially reamed, locked, intramedullary nails. However, in the polytraumatized patient perioperative complications such as fat embolism syndrome (FES) and acute respiratory distress (ARDS) are well chronicled. The reamer irrigator aspirator (RIA)has been theorized to minimize such phenomena.

METHODS

A retrospective study comparing conventional reamed nailing for femur fractures versus those treated with the RIA was conducted. From January 2005 to September 2006, 156 patients treated at our institution with an intramedullary nail met inclusion criteria. There were sixty-six patient treated with conventional reaming (group A) and ninety patients treated with the RIA (group B). The main outcome measures included length of hospital stay, rate of ARDS, pneumonia, ventilatory failure, overall pulmonary complications, healing rate and death.

RESULTS

No significant differences were found between groups with regard to patient demographics, injury severity and the incidence of head/chest trauma. In addition, no differences were found in length of hospital stay, length of ICU stay or mechanical ventilation. Overall pulmonary complications occurred in 11% (group A) and 16% (group B) respectively (p = 0.48). No fatalities were found in group A while there were four in group B, 4% (p = 0.14). No significant differences were found in delayed union versus nonunion rate between groups, while overall healing complications were seen in 7% and 14% of patients (p = 0.35) in groups A and B respectively.

CONCLUSION

No statistical significance was reached with regard to pulmonary complications, healing rates or death. However, we were unable to demonstrate favorable physiologic lung parameters with RIA use compared to conventional reaming as has been described in previous animal studies. We found a trend toward more healing complications in the RIA group, but this was not statistically significant. Further study is warranted.

A cadaver model evaluating femoral intramedullary reaming: a comparison between new reamer design (Pressure Sentinel) and a novel suction/irrigation reamer (RIA)

OBJECTIVE

To compare the intramedullary pressures developed during reaming of cadaveric femurs with the Synthes Reamer/Irrigator/Aspirator (RIA) reamer and the Zimmer Pressure Sentinel (PS) reamer, controlling for the force and speed of reaming.

METHOD

Fifteen matched pairs of frozen unpreserved femurs were used in the study. Two pressure transducers and two thermocouples were screwed into holes drilled into the femoral shaft. The femurs were stabilized in the vertical position by mechanically attaching them to a custom jig equipped with a load cell to detect the vertical component of force applied to the reamer. Proximally a linear voltage displacement transducer (LVDT) was attached to the reamer to record the continuous position of the reamer. All femurs were reamed to a diameter 2 mm larger than the narrowest point of the canal. Proximal and distal pressures, proximal and distal temperatures, applied vertical force and displacement were measured continuously throughout the reaming process. Maximum and minimum, and average proximal and distal pressures for each reamer were obtained and compared using paired t-tests. Averages were also calculated and compared in the same manner. A p-value of <0.05 was considered statistically significant.

RESULTS

The maximum, minimum and average intramedullary pressures during reaming were significantly lower with the RIA system than the PS reamer. In general, the pressures produced by the RIA system were consistently below atmospheric pressure for the majority of the reaming time. This was not true for the PS system. No appreciable temperature changes were observed during any of the trials.

CONCLUSION

The RIA reaming system significantly reduces the intramedullary pressures produced during the reaming process compared to the PS reaming system.

Rationale for reduced pressure reaming when stabilizing actual or impending pathological femoral fractures: a review of the literature

Surgical treatment for impending or actual pathologic femoral fractures due to metastatic carcinoma has been shown to improve pain and quality of life. Surgery usually involves manipulation of the intramedullary (IM) portion of the femur to provide adequate stability and to restore function. IM nailing is generally considered the preferred treatment over plate osteosynthesis for most areas of the femur due to load sharing capabilities. Several reports have shown a high incidence of oxygen desaturation, hypotension, fat or air embolism, and mortality in the surgical treatment of femoral metastatic disease. The patient with a metastatic lesion in the femur is at risk for cardiopulmonary complications associated with entering the IM canal. Complications and mortality reported in the literature are varied. Benefits of IM nailing of femoral lesions and associated complications in the literature are discussed. The theoretical benefit of aspiration and irrigation while reaming is also reviewed. Reaming while irrigating under negative pressure provided through suction may potentially minimize cardiopulmonary and oncologic complications.

Intramedullary nailing as a 'second hit' phenomenon in experimental research: lessons learned and future directions

BACKGROUND

The 'second hit' phenomenon is based on the fundamental concept that sequential insults, which are individually innocuous, can lead to overwhelming physiologic reactions. This response can be expressed in several organic systems and can be examined by measurement of several parameters.

PURPOSES

The purpose of this study was to evaluate the incidence of systemic effects of intramedullary nailing and the role of concurrent head and thoracic injuries as they have been recorded in vivo. We also wanted to determine what would be the optimal animal model for future research and what variables should be investigated.

METHODS

We reviewed the available literature of animal studies that used surgery, and particularly nailing, as a second hit. The reviewed studies were retrieved through an electronic search of the MEDLINE database. We analyzed the methods of creating the first and second hits (nailing), the characteristics of the animal models, the variables examined, and the pathophysiologic responses, which appeared after the second hit.

RESULTS

Second hit reamed intramedullary nailing was found to provoke consumption of coagulation factors, whereas the effect of unreamed nailing on coagulation factors appears inconsistent. Hemodynamic factors were affected only transiently by the second hit, whereas the pulmonary function was affected only when the first hit included lung injury.

CONCLUSIONS

Thoracic and head injuries predispose to an aggravated second hit. Primate animal models are considered to be closer to clinical reality and should be preferred for future studies. Future studies should include measurements of proinflammatory and antiinflammatory markers.

[Unreamed intramedullary nailing]

Reaming and non-reaming of intramedullary nails in long bone fractures was a controversial and even emotional topic in recent decades. This article gives an historical overview of the development in this field and presents the background to the need for unreamed nailing. Furthermore, the current state of knowledge is illustrated by describing the results of a series of randomised controlled trials. Before the year 2000 nearly all German handbooks on orthopaedic and trauma surgery recommended unreamed intramedullary nailing as a more "biological" treatment that causes less harm to vascularity with equal or even better results. Unreamed nailing was in particular advocated for the treatment of open fractures. The tide turned as randomised controlled trials conducted since 2000 gave evidence that unreamed nailing leads to a higher rate of delayed or non-union, while the advantages to blood supply and infection rate could not be proven. According to evidence based medicine isolated femur and tibia fractures should be nailed in a reamed procedure. In a severe multiple injury setting it is safer to stabilize long bone fractures with external fixators, as adverse events are described for reamed and unreamed nailing.

Systematic effects of surgical treatment of hip fractures: gliding screw-plating vs intramedullary nailing

AIM

Numerous studies have been published regarding the comparison between intramedullary nail and the dynamic hip screw and plate for the fixation of intertrochanteric fractures in elderly patients. In this paper we present a comparative study of these two methods regarding their systemic effects on this group of patients.

MATERIALS-METHODS

This is a randomized trial of 120 consecutive patients with an intertrochanteric fracture treated with either extramedullary fixation (dynamic hip screw and plate; DHS, Synthes-Stratec, Oberdorf, Switzerland) or intramedullary nail (Gamma nail, Stryker Howmedica, Freiburg, Germany and Endovis BA, Citieffe, Bologna, Italy). The parameters that we assessed pre-operatively, in addition to their demographics, included their mental state (MMSE), their nutritional and immune state and their pulmonary function. Intra-operatively we calculated the amount of radiation exposure, the amount of blood loss and the length of operative time for each procedure. Postoperatively we repeated the calculation of the mental and pulmonary state and the blood loss, during days 1, 3, and 10 and related them to the ease of the patient's mobilization.

RESULTS

Decreased bleeding and post-operative pain, reduced post-operative morbidity and faster recovery of function were better but not significant in the group of intramedullary fixation (all p>0.05). However, in the same group there were slightly more patients in whom the MMSE was falling, together with their pulmonary function, suggesting that this method probably predisposes to higher chances of pulmonary dysfunction and the possibility of pulmonary embolism.

CONCLUSION

We found no significant differences between the two methods of stabilization of these fractures regarding their systemic effects perioperatively. The classic dynamic hip screw can preserve its position as a safe and effective solution for these already vulnerable patients having sustained a trochanteric fracture against the novel intramedullary techniques.

Reaming does not add significant time to intramedullary nailing of diaphyseal fractures of the tibia and femur

BACKGROUND

Reamed intramedullary nailing is the current gold standard for the treatment of diaphyseal fractures of the femur and tibia. Current concepts of orthopedic damage control surgery for patients with multiple injuries have placed an emphasis on appropriate surgical timing, limiting blood loss, and the duration of the initial operative procedure(s). Proponents of unreamed nailing have stated that reaming places polytraumatized patients "at risk," in part because it adds to the length of the surgical procedure and may exacerbate the severity of a patient's pulmonary injury. The purpose of this study was to determine how many minutes reaming actually takes and what percentage of operative time reaming comprises during intramedullary nailing of femoral and tibial shaft fractures.

METHODS

Intraoperative timing data were collected prospectively on a total of 52 patients with 54 fractures (21 femoral and 33 tibial) who underwent reamed intramedullary nailing of acute closed or open femoral or tibial shaft fractures over a 10-month period. Total operating room, surgical, and reaming times were collected.

RESULTS

The average reaming time for femur and tibia fractures was 6.9 minutes and 7 minutes, respectively. On average, reaming accounted for 4.9% of the surgical time and 3.2% of the total operating room time for femur fractures and 4.9% of the surgical time and 3.4% of the total operating room for tibia fractures.

CONCLUSION

Our results show that reaming comprises a small percentage of the operative time and the total time a patient spends in the operating room.

Cortical perfusion and local fat occlusion after intramedullary nailing of the ovine tibia--comparison of different surgical procedures

The aim of this study was to determine whether reamed or unreamed nailing is more harmful to local bone perfusion and increases fat occlusion of transcortical vessels.

METHODS

After creating a standard fracture of the sheep tibia, reaming was performed in the first group using an experimental optimised reaming system (RE), in the second group with the conventional AO reamer (RC). Unreamed nailing was performed in the third group (UN). UHN 7.5mm titanium was inserted in all three groups. Intramedullary pressure was measured intraoperatively. Quantitative histological analyses of the bone were performed postoperatively.

RESULTS

The highest fat occlusion of transcortical vessels occurred in UN (5.7%), the lowest in RE (1.6%). The least harm to intracortical circulation was caused by RE with 28% perfused intracortical vessels compared to 17% (UN) and 18% (RC).

CONCLUSION

The experimental optimised reaming system reduces circulatory disturbance and local fat occlusion compared to the existing nailing procedures.

Fat extravasation due to unreamed and experimentally reamed intramedullary nailing of the sheep femur

AIM

To compare systemic fat extravasation in unreamed and experimentally reamed nailing.

METHODS

An osteotomy was created in the proximal third of the femoral shaft in 16 sheep, and intramedullary pressure increase and fat extravasation were monitored for the two nailing techniques.

RESULTS

The highest intramedullary pressures, median 2700 mm Hg, and highest percentages of fat extravasation, peaking at almost 90% of fat, were found for the unreamed nailing technique. The values for the reamed group were significantly lower.

CONCLUSIONS

The extravasation of intramedullary fat can be attributed to the great increase in intramedullary pressure that occurs during unreamed nailing. Correctly performed intramedullary reaming with the new reaming system produces lower pressures and much less systemic fat extravasation, reducing the risk for fat embolism.

Intramedullary nailing of the femur: current concepts concerning reaming

Intramedullary fixation has advanced to the standard of care for fractures of the femoral shaft. Current controversies center on whether to prepare the intramedullary canal by reaming, particularly in certain subsets of patients. As understanding of the local and systemic effects of reaming deepens, there is a role for maximizing the benefits of intramedullary preparation before nail fixation, while attempting to minimize the major disadvantages of this technique. Several treatment strategies have emerged to address the downsides of intramedullary reaming. The purpose of this review is to discuss the history and current knowledge of intramedullary reaming with respect to problems associated with its use and the evolution of treatment modalities and their clinical applicability for orthopaedic trauma care.

[Fat embolism during limb lengthening with a centromedullary nail: three cases]

Several methods are available for progressive limb lengthening, including centromedullary nailing, external fixation, or a combination. Each technique has its own advantages and drawbacks. In trauma victims, use of centromedullary nailing is associated with potentially fatal fat embolism. This fatal outcome might also occur during limb lengthening, particularly in bilateral procedures. To our knowledge, fat embolism has not been reported with the use of centromedullary nail for limb lengthening. This was a multicentric study of three cases of fat embolism, including one fatal outcome. In all, 36 centromedullary lengthening nails were inserted in the three centers before these acute episodes. The first two cases occurred during single-phase bilateral procedures, the third during unilateral lengthening. Fat embolism could result from several factors, as reported in the literature. While the bilateral nature of the procedure has been incriminated, the observation of an embolism during a unilateral procedure suggests other factors may be involved. Considerable increase in endomedullary pressure during reaming and insertion of the nail has been demonstrated. At the same time, there is the question as to whether the reduction of the diminution of medullary pressure by corticotomy would be an efficient way of reducing the risk of fat embolism. Based on the analysis of our three cases, we suggest that the best way to avoid fat embolism might be to drill several holes within the area of the osteotomy before reaming, in order to reduce endomedullary pressure. This can be achieved via a short skin incision, sparing the periosteum before low energy osteotomy. Since applying this protocol, the three centers have implanted 17 lengthening nails, without a single case of fat embolism.

Intramedullary nailing in femoral shaft fractures. Evaluation of a group of 101 cases

The Authors analyse the results of intramedullary nailing in a group of 101 femoral shaft fractures. Used nails: Universal Synthes (62 cases), Russel-Taylor (14), Gamma long (10), uncannulated femoral nail (9), cannulated femoral nail (4) and proximal femoral nail (2). Stabilisation of the femoral shaft fracture was possible using a reamed technique in 91 cases, unreamed in 10. All nails were locked. Dynamisation was performed in 35 cases and was not in 66. The fracture heal was faster with the reaming and dynamisation technique. Ten fractures were open (5 Gustilo I, 5 Gustilo II) and stabilisation with Universal Synthes nail (8 cases), Russel-Taylor nail (1) and Gamma long nail (1) was performed. No infection was detected. Lung embolism (6) and deep vein thrombosis (3) occurred only in the case of reamed nails. All results confirm the locking nail system as the best treatment in the shaft fractures, especially with new-generation nails.

Femoral nailing-related coagulopathy determined by first-hit magnitude: an animal study

We asked whether coagulopathy worsened during femoral intramedullary nailing in the presence of lung contusion and hemorrhagic shock and whether reamed or unreamed nailing influenced these results. In 30 Merino sheep, we induced hemorrhagic shock and/or standardized lung contusion followed by femoral nailing. Six groups of five each were assigned as follows: thoracotomy control groups treated with reamed or unreamed nailing, lung contusion groups treated with reamed or unreamed nailing, and shock and lung contusion groups treated with reamed or unreamed nailing. After lung contusion alone (first hit), the serum values of antithrombin III, factor V, and fibrinogen were considerably altered after reamed and unreamed femoral nailing (second hit) 4 hours postoperatively. In the lung contusion and shock groups, we found a substantial reduction for all serum coagulative parameters between baseline and fixation after reamed and unreamed nailing. The magnitude of the first hit is increased if hemorrhagic shock is added to a lung contusion determined by hemostatic reactions. The magnitude of the injury appears equally important as the type of subsequent surgery and should be considered in planning for fracture fixation in patients at high risk for complications.

O efeito do corticosteróide na prevenção da síndrome da embolia gordurosa após fratura de osso longo dos membros inferiores: revisão sistemática com meta-análise

OBJETIVO: Analisar a evidência disponível sobre o efeito do corticosteróide na prevenção da síndrome da embolia gordurosa (SEG) após fratura de osso longo do membro inferior e/ou pélvis. MÉTODOS: Pesquisamos as bases de dados eletrônicas do Medline, Excerpta Medica, Cochrane Library, Literatura Latino-Americana e do Caribe em Ciências da Saúde e Scientific Electronic Library Online em março de 2007. Selecionamos estudos randomizados e controlados que compararam corticosteróide com placebo (ou cuidados de rotina) na prevenção da SEG após fratura de osso longo de membro inferior e/ou pélvis. Também revisamos as referências contidas nos estudos incluídos. RESULTADOS: Seis estudos foram incluídos. O risco relativo total de desenvolver SEG foi 0,16 (IC95%: 0,08-0,35) no grupo que recebeu corticosteróide em comparação com o grupo controle. O risco relativo total de desenvolver hipoxemia foi 0,34 (IC95%: 0,19-0,59) no grupo que recebeu corticosteróide em comparação com o grupo controle. CONCLUSÃO: A análise da evidência mostrou que o corticosteróide diminui o risco de SEG e hipoxemia após fratura de ossos longos de membro inferior.

Novel technique for medullary canal débridement in tibia and femur osteomyelitis

Intramedullary infection is a challenging problem and treatment usually includes removal of infected hardware and reaming of the medullary canal. We describe a new technique for canal débridement and evaluate its infection control rate in treating osteomyelitis of the tibia and femur. We retrospectively reviewed 11 patients with posttraumatic osteomyelitis of the tibia (n = 8) or femur (n = 3). Surgery included débridement, implant removal, and reaming of the medullary canal with a new device that allows reaming under simultaneous irrigation and aspiration. At a minimum followup time of 6 months (mean, 13 months; range, 6-23 months), we observed no recurrence of infection. Complications included one partial loss of a flap, one refracture of a tibia after an automobile versus pedestrian accident, and external fixator pin tract infections in one patient. These preliminary data suggest the new reaming device may be a useful adjunct for débriding intramedullary infections of the tibia and femur.

Intramedullary canal pressure distribution: an experimental parametric study

Intramedullary instrument/device insertion during total joint replacement can generate high intramedullary pressures, with potential for clinical fat embolism syndrome. We evaluated effects of process parameters on intramedullary pressure generated when hammering an implant into a simulated femur analogue. Lower implant insertion speed, lower hammering force, a rubber- compared with steel-tipped hammer and a larger synthetic bone-to-implant radial gap reduced intramedullary pressure generated. Number of hammer strikes required to insert an implant increased with increasing marrow viscosity, whereas intramedullary pressure decreased with increasing viscosity. Significant intramedullary pressure reduction is obtained by applying more strikes of lower peak force using a rubber hammer tip, as opposed to fewer larger strikes. Caution should be exercised when instrumenting the distal femur, where viscosity is low and very high intramedullary pressures can be generated.

Early Unreamed Intramedullary Nailing of Femoral Fractures is Safe in Patients With Severe Thoracic Trauma

BACKGROUND

The timing of fixation of femoral fractures in multiply injured patients with severe thoracic trauma is discussed controversially. Some authors recommend damage control surgery, whereas other authors prefer early definitive treatment. The aim of our study was to investigate the effect of early definitive fixation of femoral fractures on outcomes in multiply injured patients with severe thoracic trauma.

METHODS

Between May 1, 1998 and December 31, 2004, 578 severely injured patients were admitted to our institution. Forty-five patients met the inclusion criteria for the study cohort (severe thoracic trauma and femoral fracture stabilized with unreamed intramedullary nailing [IMN] within the first 24 hours) and 107 patients were selected for the control cohort (severe thoracic trauma without any lower extremity fracture). Inclusion criteria for both cohorts were age 15 to 55 years with blunt trauma (e.g. motor vehicle collisions, falls) including severe thoracic trauma (Abbreviated Injury Scale [AIS] score >or=3) and Injury Severity Score (ISS) >or=18. For comparison between the cohorts data on patients status (Glasgow Coma Scale score at arrival, Revised Trauma Score, Trauma and Injury Severity Score survival prognosis, Simplified Acute Physiology Score II score), treatment (intubation rate, thoracic drainage, surgery), and outcomes (duration of intensive care unit stay and ventilation, rate of adult respiratory distress syndrome [ARDS], multiple organ failure syndrome [MOFS], and mortality) were selected from hospital databases. Dichotomous data were analyzed by chi test; continuous data were analyzed by Student's t test. Any values of p < 0.05 were considered significant for any test.

RESULTS

Both cohorts were comparable with regard to demographic data, ISS, AIS score in the thoracic region, and incidence and severity of brain injury. There was no difference in dependent parameters in both cohorts. Rates of ARDS, MOFS, and mortality were not negatively influenced by early unreamed IMN.

CONCLUSION

Early unreamed IMN of femoral fractures in multiply injured patients with severe thoracic trauma is a safe procedure and seems to be justified to achieve early definitive care.

Complications associated with the use of a titanium tibial nail

Intramedullary nailing is the treatment of choice for unstable or displaced tibial fractures. Titanium nails have been advocated for their improved biocompatibility and biomechanical properties but concerns are held about increased complications. We present results of 225 tibial fractures in 221 patients (90% follow-up) treated with the ACE titanium tibial nail (DePuy International Limited, Leeds, UK) inserted between 1995 and 2003 in one hospital department, which show no increased complications compared with the published literature. Eighty-two percent of the patients were male with a median age of 33 years. The mechanism of injury was RTA (52%), Sport (22%) and other (26%). Forty-one percent of the fractures were open. The general complication rate represents the published literature whereas only 32% patients developed knee pain compared with the 40-57% previously reported. Median union time was unaffected by open injury, reaming or age. Ninety (43.3%) patients required re-operation of which 23 (11%) had a second re-operation. In total 43 (20.7%) nails were removed, without any complication as previously reported for this nail.

Similar Central Hemodynamics but Increased Postoperative Oxygen Consumption in Unreamed Versus Reamed Intramedullary Nailing of Femoral Fractures

BACKGROUND

Patients undergoing intramedullary nailing of long bone fractures have pathologically altered pulmonary vascular tone, right heart strain, and transient impairment of pulmonary gas exchange. The purpose of this study was to examine the acute differences in cardiopulmonary variables between reamed and unreamed nailing techniques in 18 (9 + 9) healthy patients with unilateral femoral shaft fractures.

METHODS

Intramedullary nailing was performed under general anesthesia within 12 hours after the trauma. For blood sampling, recording, and measurements, the patients were cannulated with radial artery and pulmonary artery catheters. Changes in central hemodynamics and oxygenation were studied pre-, peri-, and postoperatively for 16 to 20 hours.

RESULTS

Abnormally high pulmonary shunting (23 +/- 12% in the reamed and 27 +/- 11% in the unreamed group) was observed before the operation. The trends of all variables were very similar in both groups except for the last phase in which the mixed venous oxygen saturation tended to be lower (65 +/- 8 vs. 70 +/- 5%) and the oxygen consumption index was higher (186 +/- 21 vs. 151 +/- 20 mL/min/m) in the unreamed group than in the reamed group (p < 0.05). The timepoints most strenuous to the heart were at the end of operation and in the recovery room.

CONCLUSIONS

The unreamed intramedullary nailing technique does not offer any advantage in cardiopulmonary variables over the reamed technique. In both groups, there was considerable deviation in over 10 cardiopulmonary variables from normal reference values during the study. We suggest the use of invasive monitoring on patients with a long bone fracture and poor preoperative oxygenation or a history of cardiopulmonary or cardiac disease.

Fat embolism: the reaming controversy

Intramedullary nailing is the preferred treatment method for stabilizing femoral diaphyseal fractures. Despite its superior biomechanical advantages over other implants, its use, particularly in selected groups of patients, has been questioned because of the possible harmful systemic effects of intramedullary reaming. The increase in intramedullary canal pressure during intramedullary nailing can result in intravasation of bone marrow and fat into the venous blood system. The subsequent consequences can be fat embolism syndrome (FES), adult respiratory distress syndrome (ARDS), and multiple organ failure. The lung seems to be the primary target for fat embolization and for the mediated effects primed by inflammatory reactions. In laboratory studies, both reamed and unreamed intramedullary nailing has been shown to alter selected pulmonary variables. Although transient, this effect appears to be more prominent with reamed than unreamed techniques. Additional studies are required to determine whether a subgroup of trauma patients is adversely affected by intramedullary reaming, thus necessitating other fixation techniques.

Pathophysiological advantages of rinsing-suction-reaming (RSR) in a pig model for intramedullary nailing

Although reamed intramedullary nailing has been one of the greatest advances in modern fracture care, the concomitant increase in medullary cavity pressure leads to intravasation of bone marrow content into the blood stream, an effect that can evoke serious systemic reactions. A newly developed rinsing-suction-reamer (RSR) was able to substantially reduce the pressure and bone marrow intravasation content during experimental femoral nailing. We investigated the pathophysiological effects using the RSR, testing the hypothesis that by reducing marrow fat embolization, RSR would also reduce the activation of coagulation compared with the universal AO-Reamer (AOR) and comparable to external fixation. Twenty-two pigs were treated with either simulated external fixation or reamed femoral nailing using AOR or RSR. During surgery, the intramedullary pressure was measured and intravasation of medullary material was quantified. After surgery, the pigs were kept anaesthetised and monitored for 6 h. At defined intervals, serological, hematological, and hemodynamic parameters were evaluated. The RSR was significantly superior when compared to AOR with regard to the generation of intramedullary pressure and fat embolization; however, with external fixation the values were even lower. The evaluation of other parameters revealed no clear differences between the two reamers and the external fixator. The pig model showed that RSR led to a significant reduction of the intramedullary increase in pressure and fat intravasation compared to AOR. Although the reduction of fat embolism by RSR is not associated with pathophysiological changes, RSR can have advantages for the treatment of femoral fractures.

Risk factors for respiratory failure following femoral fractures: the role of multiple intramedullary nailing

Controversy exists on the relationship between intramedullary nailing (IMN) and the timing of fixation in the development of respiratory failure (RF) following femoral fractures. The purpose of this study is to identify risk factors for RF and evaluate the role of multiple IMN in the above setting. We prospectively observed 126 consecutive patients with femoral fractures for the development of RF. Twenty-one patients (17%) developed RF. This occurred before fracture fixation in 11 patients and after IMN in 10 patients; five after multiple IMN and five after a single IMN procedure. Patients who underwent multiple IMN demonstrated a significant increase of RF after fracture fixation (5/8,) compared to patients with one IMN procedure (5/114, 4.4%, p<0.001). Stepwise regression analysis identified two independent RF risk factors: thoracic injury and multiple IMN (odds ratios: 40.6 and 25.6, respectively). Thoracic injury and multiple IMN procedures are independent risk factors for RF in patients with femoral fractures, and the combination of the above conditions is highly predictive of the development of RF.

Secondary effects of femoral instrumentation on pulmonary physiology in a standardised sheep model: what is the effect of lung contusion and reaming?

Intramedullary nailing is the treatment of choice for patients with femoral shaft fractures. However, there is an ongoing debate in multiple trauma patients with associated lung contusion when primary or secondary definitive stabilisation of the long bone fracture should be performed, as nailing is thought to play an important role in the pathogenesis of adult respiratory distress syndrome (ARDS). In a standardised sheep model, this study aimed to quantify the development of acute pulmonary endothelial changes, to assess the activation of polymorphonuclear leucocytes (PMNL) and to observe the effects on the coagulation system associated with the reamed nailing procedure. Furthermore, the effect of coexisting lung contusion in an experimental model was evaluated. The animals were randomly assigned to one of four different groups (6 animals/group). In control groups, only a sham operation (thoracotomy) was performed, whereas in study groups, lung contusion was induced prior to femoral stabilisation either by external fixation or reamed femoral nailing. Using bronchoalveolar lavage (BAL) pulmonary permeability changes were quantified and PMNL activation was assessed by chemiluminescence. Additionally PMNL diapedesis and interstitial lung oedema were determined by histological analysis. All animals were sacrificed 4 h after the start of the femoral instrumentation. Without an associated lung injury, instrumentation of the femoral canal with the reamed nailing technique induced a transient increase in pulmonary permeability. In the face of an induced lung contusion, reamed femoral nailing resulted in significant increases in PMNL activation, pulmonary permeability and interstitial lung oedema, compared with external fixation. Without pulmonary contusion, reaming of the femoral canal was associated with a transient increase in pulmonary permeability. This was exacerbated in the presence of lung contusion along with increased PMNL activation. External fixation did not provoke similar changes. The findings of this study support the view that reaming of the femoral canal should be avoided in polytrauma patients with severe chest trauma as it could act as an additional stimulus for adverse outcome. Temporary external fixation appears to be a safe method for fracture stabilisation until inflammatory and coagulatory disturbances after trauma have been normalized.