Similar central hemodynamics and oxygenation in reamed and unreamed intramedullary nailing of tibial fractures

BACKGROUND: Reamed intramedullary nailing of a long bone fracture is considered to be of crucial importance in the genesis of pulmonary disturbances. Use of unreamed nailing technique has been encouraged to avoid temporary deterioration in lung functions. METHODS: Central hemodynamic changes were recorded in 20 healthy adults with a unilateral simple tibial fracture undergoing reamed or unreamed intramedullary nailing. The patients were cannulated with a pulmonary artery catheter. Intramedullary nailing was performed during general anesthesia. Pre- and immediate postoperative hemodynamic variables were compared. RESULTS: Unchanged cardiac performance but pathologically altered pulmonary vascular tone were unrelated to the type of nailing technique. Increased oxygen consumption was observed as well. CONCLUSION: Changes in cardiac and pulmonary hemodynamics are already present after the trauma and before the intramedullary nailing procedure.     

Tibial fractures Reamed versus unreamed intramedullary nailing

AMEDLINEsearchwasperformedtoidentifystudiespublishedfromJanuary1997toNovember2003com-paringreamedintramedullary(IM)nailingwithun-reamedIMnailingfortibialfractures.Fromalistof16articles,threerandomizedclinicaltrialscomparingreamedIMnailingtounreamedIMnailingwereidentified.Weincludedstudiesexaminingbothopenandclosedtibialfractures.Weexcludedanalysesofnonrandomizedtrials.StudiesStudy1KeatingJF,OBrienPJ,BlachutPA,etal(1997)Lockingintramedullarynailingwithandwithoutreamingforopenfractur…     

Prospective randomized study of reamed versus unreamed femoral intramedullary nailing: an assessment of procedures

OBJECTIVE: To determine whether the procedure of unreamed femoral nailing is simpler, faster, and safer than reamed femoral intramedullary nailing. DESIGN: Prospective randomized. SETTING/PARTICIPANTS: One hundred femoral shaft fractures without significant concomitant injuries admitted to an academic Level 1 urban trauma center. INTERVENTION: Stabilization of the femoral shaft fracture using a reamed or unreamed technique. OUTCOME MEASUREMENTS: The surgical time, estimated blood loss, fluoroscopy time, and perioperative complications were prospectively recorded. RESULTS: One hundred patients with 100 femoral shaft fractures were correctly prospectively randomized to the study. Thirty-seven patients received reamed and sixty-three patients received unreamed nails. All nails were interlocked proximally and distally. The average surgical time for the reamed nail group was 138 minutes and for unreamed nail group was 108 minutes (p = 0.012). The estimated blood loss for the reamed nail group was 278 milliliters and for the unreamed nail group 186 milliliters (p = 0.034). Reamed intramedullary nailing required an average of 4.72 minutes, whereas unreamed nailing required 4.29 minutes of fluoroscopy time. Seven perioperative complications occurred in the reamed nail group and eighteen in the unreamed nail group. Two patients in the unreamed group required an early secondary procedure. Iatrogenic comminution of the fracture site occurred during three reamed and six unreamed intramedullary nailings. Reaming of the canal was required before the successful placement of three nails in the unreamed group because of canal/nail diameter mismatch. CONCLUSIONS: Unreamed femoral intramedullary nailing involves fewer steps and is significantly faster with less intraoperative blood loss than reamed intramedullary nailing. The unreamed technique, however, was associated with a higher incidence of perioperative complications, although the difference was not statistically significant (p = 0.5).     

扩髓与非扩髓髓内钉固定术治疗成人股骨干骨折的系统评价

目的对扩髓与非扩髓的髓内钉固定术治疗成人股骨干骨折的疗效进行评价。方法按照Cochrane系统评价的方法，计算机检索Medline（1966年至2004年9月）、Embase（1966年至2004年9月）、Cochrane图书馆（2004年第三期）及中国生物医学数据库（1979年至2004年9月），并采用手工检索等方法收集会议文献。文献检索无语种限制。收集所有相关随机对照试验，采用Cochrane协作网提供的软件Revman4．2．3进行Meta分析，以获得扩髓与非扩髓的髓内钉固定术治疗成人股骨干骨折的疗效及其安全性是否有差异的相关证据。结果经全面检索及筛查后，共纳入5个随机对照试验进行评价。Meta分析表明，扩髓髓内钉固定能降低成人股骨干骨折的不愈合率[RR=O．38，95％置信区间（0．17，0．88），P=0．02]、内固定失效率[RR=0．45，95％置信区间（0．21，1．00，P=0．05]和减少骨折愈合时间[WMD=-10．90，95％置信区间（-18．16，-3．64），P=0．003]。结论与非扩髓髓内钉固定相比，扩髓固定能降低成人股骨干骨折的不愈合率。但扩髓与否与内固定失效率、骨折愈合时间、肺部并发症、感染等的关系，以及骨折开放与否、是否合并多发伤及骨折的部位等对上述指标的影响有待于进一步研究。     

股骨干骨折--扩髓和不扩髓髓内钉比较

治疗股骨干骨折，采用不扩髓髓内钉比扩髓髓内钉手术时间明显缩短，而且失血也少。但是，扩髓钉的骨愈合更快，延迟愈合更少。两者都没有显著增加包括肺损害等其它并发症的风险。功能结果不能确定。     

Pulmonary fat embolism after reamed and unreamed nailing of femoral fractures

Background

To determine whether reamed or unreamed intramedullary nailing of femoral fractures results in higher incidence of pulmonary fat embolism, three different methods of intramedullary nailing were compared in sheep. To analyze the presence of bone marrow fat embolism in pulmonary arteries, histological evaluation was undertaken using a quantitative computer-assisted measurement system.

Methods

In this experimental model of 27 female Swiss alpine sheep, an osteotomy of the proximal femur was conducted in each animal. Then, the animals were divided into three groups according to the method of treatment: two different reamed intramedullary nailing techniques and an unreamed nailing technique were used.In the first group “ER” (experimental reamer; n = 9), the nail was inserted after reaming with an experimental reamer; in the second group “CR” (conventional reamer; n = 7), the intramedullary nail was inserted after reaming with the conventional AO-reamer. In the third group “UN” (unreamed; n = 8) unreamed nailing was performed. During the operation procedure intramedullary pressure was measured in the distal fragment.After sacrificing the animals, quantitative histological analyses of bone marrow fat embolism in pulmonary arteries were done using osmium tetroxide fixation and staining of the fat.

Results

The measurement of intramedullary pressure showed significantly lower values for reamed nailing than for the unreamed technique. The quantitative histological evaluation of lung vessels concerning bone marrow fat embolism revealed a statistically significant difference between reamed and unreamed insertion of the nail: 7.77% ± 6.93 (ER) and 6.66% ± 5.61 (CR) vs. 16.25% ± 10.05 (UN) (p < 0.05) of the assessed lung vessels were filled with fat emboli. However, no difference was found between the traditional and experimental reamer.

Conclusions

Intramedullary nailing after reaming is a safe procedure with low systemic embolisation when compared to the unreamed insertion of the nail.     

Central hemodynamics during reamed intramedullary nailing of unilateral tibial fractures

BACKGROUND: Intramedullary nailing of a long-bone fracture results in intravasation of bone marrow contents into the right atrium and pulmonary vascular bed and, therefore, may alter cardiac and pulmonary hemodynamics. METHODS: Central hemodynamic changes were recorded in 12 healthy adults with a unilateral simple tibial fracture undergoing intramedullary nailing. The patients were cannulated with a pulmonary artery catheter. Reamed intramedullary nailing was performed during general anesthesia. Preoperative and immediate postoperative hemodynamic variables were compared and intraoperative changes studied. RESULTS: During the operation, the right ventricular preload as represented by central venous pressure and the right ventricular afterload as presented by mean pulmonary arterial pressure increased significantly. Preoperative and postoperative arterial oxygen tension values demonstrated hypoxia. Abnormal pulmonary shunting and increased oxygen consumption were observed as well. CONCLUSION: Changes in cardiac and pulmonary hemodynamics are already present after the trauma and before the reamed intramedullary nailing procedure.     

Transesophageal echocardiography in quantification of emboli during femoral nailing: reamed versus unreamed techniques

We quantified the embolic load to the lungs created with two different techniques of femoral nailing. Eleven patients with 12 traumatic femur fractures were randomized to reamed (7 fractures) and unreamed (5 fractures) groups. Intramedullary nailing was with the AO/ASIF* universal reamed or unreamed nail. Transesophageal echocardiography (TEE) was used to evaluate the quantity and quality of emboli generated by nailing. Data were analyzed using software that digitized the TEE images and quantified the area of embolic particles in each frame. The duration of each level of embolic phenomena (zero, moderate, severe) was used to determine total embolic load with various steps (fracture manipulation, proximal portal opening, reaming, and nail passage). Manual grading of emboli correlated highly with software quantification. Our data confirm the presence and similarity of emboli generation with both methods of intramedullary nailing. Unreamed nails do not protect the patient from pulmonary embolization of marrow contents.     

Fracture healing after reamed and unreamed intramedullary nailing in sheep tibia

Intramedullary nailing is a well-established method for stabilisation of long-bone shaft fractures. It is still a controversy as to whether the procedure should be done by an unreamed or reamed technique.In the present animal study, 24 sheep were treated with intramedullary nailing. Midshaft fractures (Arbeitsgemeinschaft für Osteosynthese (AO) type 42-A2/3) were created. Eight sheep were treated with an unreamed nailing technique (UN), a further eight sheep underwent tibia nailing by the reamed technique using the conventional AO reaming system (RC) and in a further eight sheep, reamed nailing was performed using an experimental reaming system (RE). Intra-operatively, the intramedullary pressure was measured and, during a healing time of 10 weeks, the growth of callus formation was labelled with fluorescence markers after 4 and 6 weeks. After 10 weeks, the animals were euthanised and the quality of fracture healing was determined by recording stiffness in torsion, antero-posterior and mediolateral bending and the load at yield. In addition, the callus formation at the fracture zone was evaluated by fluorescence microscopy and macroradiographs.The results showed a decrease of intramedullary pressure when reamed nailing was performed with the RE (72.5 mmHg) system compared with the conventional AO reaming system (227 mmHg). Mechanical testing did not reveal any significant differences either for torsional or bending stiffness or for load at yield for any of the three procedures. Histological evaluation showed a similar callus formation for the UN group and the RE group. Callus formation in the UN (65 mm²) and RE (63 mm²) groups showed a higher increase during the first 6 weeks than those treated with the conventional AO reaming system (27 mm²). This means that, especially during the first weeks of fracture healing, damage to the bone by the reaming process can be reduced by reaming with a reaming device with lowered cutting flutes and smaller drive-shaft diameter.Intramedullary pressure can be significantly reduced by using reaming systems with reduced drive-shaft diameters and deepened cutting flutes. In the early phase of fracture healing, callus formation can be influenced positively when using the RE system.     

The incidence of non-union following unreamed intramedullary nailing of femoral shaft fractures

Introduction

Stabilisation of fractures with an intramedullary nail is a widespread technique in the treatment of femoral shaft fractures in adults. To ream or not to ream is still debated. The primary objective of this study was to determine the incidence of non-union following unreamed intramedullary stabilisation of femoral fractures. Secondary objectives were intra- and postoperative complications and implant failure.

Methods

Between March 1995 and June 2005, 125 patients with 129 traumatic femoral shaft fractures were treated with as unreamed femoral nail. From this retrospective single centre study, 18 patients were excluded due to insufficient follow up data, including 1 patient who died within 2 days after severe head injury. Sixty-six patients had suffered multiple injuries. 21 fractures were open. According to the AO classification, there were 54 type A, 42 type B, and 14 type C fractures. Dynamic proximal locking was performed in 44 cases (36 type A and 8 type B fractures).

Results

Non-union occurred in two patients (1.9%; one type B and one type C fractures). Intra-operative complications were seen in three patients (2.8%). Postoperative in-hospital complications occurred in 29 patients (27%). Local superficial infection occurred in two patients (1.9%), there were no cases of deep infection. Implant failure occurred in three patients (2.8%): nail breakage was seen in two patients.

Conclusion

In this study, the incidence of non-union following unreamed intramedullary nailing is low (1.9%) and comparable with the best results of reamed nailing in the literature.     

Retrospective analysis of healing problems after reamed and unreamed nailing of femoral shaft fractures

168 fractures of the femoral shaft treated by intramedullary nailing were analyzed retrospectively. From 1986-1992 116 fractures had been treated with the reamed AO universal nail (RFN) and from 1993-1996 52 fractures with the AO unreamed femoral nail (UFN). In 24% of the RFN-group and in 2% of the UFN-group (p < 0.0001) open reduction of the fracture had been necessary. The time to radiological consolidation was similar in both groups (18.1 weeks +/- 6.1 vs. 18.3 weeks +/- 5.7, [mean +/- SD]). Delayed unions were less frequent in the RFN-group than in the UFN-group (3% vs. 13%, p = 0.01). Non-unions occurred in the RFN-group in 4%, in the UFN-group in 8%, the difference is not statistically significant (p = 0.46). Fractures with impaired consolidation (delayed-unions and non-unions) in the RFN group were distributed randomly along the femoral diaphysis, whereas all 11 fractures with retarded healing in the UFN group were short transverse or oblique fractures localized immediately distal to the femoral isthmus. We believe that there is mainly a mechanical reason for this phenomen, in addition to fracture type and fracture localization the (insufficient) length of the unreamed nails might have impaired stability further. The different factors should be investigated in larger series. As a consequence we now treat transverse and short oblique fractures of diaphyseal femoral fractures distal to the femoral isthmus with a RFN whereas in other types and localizations of diaphyseal femoral fractures we continue to use the UFN with special attention to maximal nail diameter and length.     

多发伤中股骨干骨折的一期扩髓髓内钉固定

目的探讨多发伤中股骨干骨折一期扩髓髓内钉固定是否会增加并发症的发生率及死亡率。方法采用回顾性对比研究,依据下列标准选择病例:(1)年龄为14~65岁;(2)多发伤,且ISS>16;(3)住院时间不少于48h;(4)病史中无明显影响全身状况的疾病,如糖尿病,慢性心、肺、肾功能不全等;(5)有股骨干骨折,且进行了扩髓髓内钉手术,不包含外固定支架或钢板、牵引及石膏固定和非扩髓髓内钉固定者。将符合上述标准的192例按受伤至手术时间划分为两组,A组为≤24h手术者(一期扩髓组,76例),B组为>24h手术者(116例),将两组间合并伤情况、ISS、住院时间、ICU时间、并发症、死亡率及合并休克率情况进行比较。结果经统计学处理,两组的股骨开放伤发生率(A组56.6%,B组34.5%,χ2=7.545,P<0.001)、合并休克率(A组48.7%,B组31.0%,χ2=6.078,P<0.001)及住院时间[A组(16.1±6.5)d,B组(29.3±9.3)d,t=10.766,P<0.001]差异有显著性,而在其他方面差异均无统计学意义。结论在多发伤患者中,只要能控制休克,保证生命体征平稳,对股骨干骨折行一期扩髓髓内钉固定不会增加患者的并发症发生率及死亡率,可促进患者早日康复,缩短住院时间,从而减少住院费用。     

Open versus closed intramedullary nailing of femoral shaft fractures

A retrospective study was performed including only fractures involving the middle three fifths of the femoral shaft with a minimum of 2 years followup. There were 65 fractures in Group I treated with the closed technique utilizing the image intensifier. These were compared with 65 fractures treated with open reduction and nailing. Followup averaged 4 years (Group II). Group 1 had 92% satisfactory results; Group II achieved 97% satisfactory, not statistically significantly different. Our recommendations are delaying the procedure did not appear to be advantageous; excluding the fractures with segmental bicortical loss, there are limited indications for locked nails in these fractures; the decision to use a specific type of internal fixation should be based on the fracture pattern, the surgeon's experience, and the equipment available; if a closed technique is chosen, be prepared to open the fracture if a satisfactory closed reduction cannot be attained. This, in our study, did not increase the risk of reducing the functional result.     

Computational comparison of reamed versus unreamed intramedullary tibial nails.

We compared, via a computational model, the biomechanical performance of reamed versus unreamed intramedullary tibial nails to treat fractures in three different locations: proximal, mid-diaphyseal, and distal. Two finite element models were analyzed for the two nail types and the three kinds of fractures. Several biomechanical variables were determined: interfragmentary strains in the fracture site, von Mises stresses in nails and bolts, and strain distributions in the tibia and fibula. Although good mechanical stabilization was achieved in all the simulated fractures, the best results were obtained in the proximal fracture for the unreamed nail and in the mid-diaphyseal and distal fractures for the reamed nail. The interlocking bolts, in general, were subjected to higher stresses in the unreamed tibial nail than in the reamed one; thus the former stabilization technique is more likely to fail due to fatigue.     

Effect of acute reamed versus unreamed intramedullary nailing on compartment pressure when treating closed tibial shaft fractures: a randomized prospective study

OBJECTIVE: To compare anterior and deep posterior compartment pressures during reamed and unreamed intramedullary nailing of displaced, closed tibial shaft fractures. DESIGN: Randomized prospective study. SETTING: University Hospital/Level I trauma center. PATIENTS: Forty-eight adults with forty-nine fractures treated with intramedullary nailing within three days of injury. INTERVENTION: After intraoperative placement of compartment pressure monitors, the tibia fractures were treated by either unreamed intramedullary nailing or reamed intramedullary nailing. A fracture table and skeletal traction were not used in any of these procedures. MAIN OUTCOME MEASUREMENTS: Compartment pressures and deltaP ([diastolic blood pressure] - [compartment pressure]) were measured immediately preoperatively, intraoperatively, and for twenty-four hours postoperatively. RESULTS: Compartment syndrome did not occur in any patient. Peak average pressures were obtained during reaming in the reamed group (30.0 millimeters of mercury anterior compartment, 34.7 millimeters of mercury deep posterior compartment) and during nail insertion in the unreamed group (33.9 millimeters of mercury anterior compartment, 35.2 millimeters of mercury deep posterior compartment). The average pressures quickly returned to less than thirty millimeters of mercury and remained there for the duration of the study. The deep posterior compartment pressures were lower in the reamed group than in the unreamed group at ten, twelve, fourteen, sixteen, eighteen, twenty, twenty-two, and twenty-four hours postoperatively (p < 0.05 at each of these times. A statistically significant difference between anterior compartment pressures could not be shown with the numbers available. The deltaP values were greater than thirty millimeters of mercury at all times after nail insertion in both the reamed and unreamed groups. CONCLUSION: These data support acute (within three days of injury) reamed intramedullary nailing of closed, displaced tibial shaft fractures without the use of a fracture table.     

Mortality after reamed intramedullary nailing of bilateral femur fractures

We performed retrospective review of 743 patients treated with reamed intramedullary nailing of a femoral shaft fracture was done to assess the clinical impact of bilateral femur fractures on the mortality, hospital stay, and length of intensive care treatment in patients with blunt trauma. Unilateral injuries occurred in 689 patients and bilateral injuries occurred in 54 patients. Mortality in patients with bilateral femur fractures was 5.6% compared with 1.5% in patients with unilateral femur fractures. The two groups were analyzed using multiple linear regression and logistic regression with age and Injury Severity Scores as covariants to allow for comparison of similarly injured groups as predicted by the Injury Severity Scores. Bilateral femur fractures still were associated with a significantly higher mortality, longer length of stay in the hospital, and longer length of stay in the intensive care unit. As expected, when analyzed separately, patients with bilateral femur fractures had significantly higher Injury Severity Scores, longer lengths of stay in the intensive care unit, and longer lengths of stay in the hospital. Patients with bilateral femur fractures have an increased mortality when compared with patients with unilateral femur fractures after controlling for Injury Severity Score and age. When used alone, the Injury Severity Score underestimates the contribution of a second femur fracture.     

Malrotation following reamed intramedullary nailing of closed tibial fractures

Background:

Rotational malalignment after intramedullary tibial nailing is rarely addressed in clinical studies. Malrotation (especially >10°)of the lower extremity can lead to development and progression of degenerative changes in knee and ankle joints. The purpose of this study is to determine the incidence and severity of tibial malrotation after reamed intramedullary nailing for closed diaphyseal tibial fractures.

Materials and Methods:

Sixty patients (53 males and 7 females) with tibial diaphyseal fracture were included in this study. The mean age of the patients was 33.4±13.3 years. All fractures were manually reduced and fixed using reamed intramedullary nailing. A standard method using bilateral limited computerized tomography was used to measure the tibial torsion. A difference greater than 10° between two tibiae was defined as malrotation.

Results:

Eighteen (30%) patients had malrotation of more than 10°. Malrotation was greater than 15° in seven cases. Good or excellent rotational reduction was achieved in 70% of the patients. There was no statistically significant relation between AO tibial fracture classification and fibular fixation and malrotation of greater than 10°.

Conclusions:

Considering the high incidence rate of tibial malrotation following intramedullary nailing, we need a precise method to evaluate the torsion intraoperatively to prevent the problem.