Clinical Analysis Of Tibial Fracture Treated By Reamed Intramedullary Nailing

Objective To evaluate the effect of the reamed intramedullary nailing fortibial fractures.Methods This study reviews 72 cases of tibial fractures treated with reamedintramedullary nailing from January 2003 to June 2005 ,including 58 closedfractures and 14 open fractures. There is 51 male and 21 female with mean age39 years ( range 18～62 years ). According to the AO /ASIF classification therewere 23 type A , 34 type B and 15 type C. Duration from injury to operationwas 5 days ( 6 hours – 10 days ).Results All cases were followed up and mean time is 10 months ( 6 – 18months ) . All fractures were union and mean union time was 21 weeks ( 17 –33 weeks ). There was no delayed union and malunion , no breaked nail andscrew , no osteomyelitis and no pulmonary dysfunction . The nail was taken outin 45 cases . Tibial fracture was happened only in one case which sufferedviolence again , but the fracture site was different .Conclusion The result is satisfactory in bone healing ,early mobilization,functional recover,pulmonary function,fixation failure and infection with thereamed intramedullary nailing to be treatment of the tibial fracture . It is aperfect method .Intramedullary nailing has been used to treat fracture of long bones forover 60 years.With the progress of technology,intramedullary nailings havebeen extensively accepted as a standard therapy. The idea of interlockingintramedullary nailing introduced by Grosse and Kempf increases themechanical characteristic of marrow interstitial implant and clinic indications.According to reaming or not ,the intramedullary nailing can be devided intoreamed and undreamed.There always has a lot of arguments for whether itshould be reamed .Effect to blood supply after reaming: Reaming the bone marrow maycause directly injury and heat injury to capillary at the same time the increasingof marrow pressure forces the fat embolus into capillary and forms embolism.All of these destroy the blood supply of endosteum and affect the union offracture. there is extensive inosculans among the intramarrow , extramarrowand periosteum capillary network .Blood supply of cortical bone come from themarrow .If it was destroyed ,the periosteum and surrounding soft tissue wouldbe hyperemia greatly.The direction of cortical bone blood supply will change .Itis good to rebuilding the intrinsic cycle of medulla.Then some scholar thinkreaming the medulla won't affect the union of bone . Scholars do not agree withthe time of rebuilding vessels after reaming.Effect to union of femoral fracture: A lot of scholars have the sameopinion that reaming is much better than unreaming in the effect of union offracture. A study shows: reaming medullar can extensively decrease the uniontime ,rate of nonunion and malunion .But some researchers think the occuranceof nonunion is closely related to the AO's division of fracture .Some otherresearch showed that undreamed nailing was greatly better than reamed nailingboth in the quantity and forming time of bony callus,and the difference wassignificant in statistic.Effect to union of tibial fracture: Generally it is thought that the bloodsupply of shaft of tibia mostly come from tibial nutrient artery system ,which isthe branch of posterior tibial artery .The other source of blood supply isperiosteum vessel system .The artery is abundant in periosteum,epiphysis andmetaphysis in superior segment of tibia ,then they can provide enough bloodsupply for union of fracture.But in the middle and inferior segment of tibiathere is little muscles and fascias attached ,intramedullary artery is the mainsource of blood supply , whereas the process of reaming destroy severely theblood supply and prolong the time of union.So the method of unreaming in themiddle and inferior segment of tibia can shorten the time of union obviouslythan reaming,while in the superior segment of tibia there is no significantdifference between reaming and unreaming .But some scholar have differentopinion that reming is much better than unreaming .They said that the uniontime and nonunion rate was higher obviously in reamed nailing than that inundreamed nailing and the difference was significant.The tibiofibular openfracture is an injury of high energy which destroys the blood vessel inperiosteum and damages the soft tissue around the fracture and decrease theblood supply in the shaft of tibia.Reaming the medullary cavity will fartherdamage the blood supply in the shaft of tibia which have been partly destroyedand then affect the union of fracture. So some scholars suggest that the reamednailing should be used in the closed fracture which don't have obvious damagein the soft tissue ,and unreamed nailing is the best choice for open fractureespecially in which have serious soft tissue damage .But some other researchshave different conclusion: reamed intramedullary nailing is the safe andeffective method for tibial open fracture .Effect to pulmonary function: first reaming do the biggest effect tointramedullary pressure , because there are all medullary fat with hyperviscosityin the medullary cavity .While the next inserting of nailing will increase thepressure smaller relatively , and this is the reason why undreamed nailingincrease the pressure when inserting. The increasing of intramedullary pressurewill force the fat into Havers'canals and nutrient vessel ,then run throught thevessel of cortical bone and periosteum into circulation system , at last run intolung. So increasing of pressure becomes the most important factor . But theincreasing is not associated only with reaming or unreaming , the mechanics inthe medullary cavity ,the geometry of medullary cavity itself and the mucilagecharacteristic in the medullary cavity all can affect obviously the pressure ofintramedullar.If the marrow was sucked out before reaming ,the pressure couldbe decreased obviously when reaming . The pressure can be also charged bychanging the method of reaming .Because the diameter of fat drop exceeds10um which is larger than that of pulmonary capillary ,the fat drop can notpass through the capillary and is obstructed at the lung ,which causes increasingof pulmonary artery pressure.The fat which run into pulmonary vessel stimulatelipoidase , generate free fatty acid and stimulate the platelet and othercytotoxicity media, then initiate acute inflammatory reaction and causepulmonary edema even ARDS or FES.But there is still arguments aboutwhether the fat embolus that run into the lung can cause damage of pulmonaryfunction and whether unreaming can prevent the damage of lung .A studyshows : both reamed and unreamed nailing can cause increasing of pulmonarycapillary permeability ,unreamed nailing can also increase neutrophil.But allof these are not found damage of pulmonary function ,maybe the damage is acomplex process which multiple factors act each other.Reaming may make thedamage serious in the patient with pulmonary functional defect or seriousthoracic injury .The study showed : reaming the femur would only cause templepulmonary permeability increasing ,while the neutrophil cytoactive ,pulmonarypermeactive and interstitial edema were obviously higher in reamed nailingthan that in external fixation in the patients with pulmonary injury. Somescholars hold the different opinion,they think reaming the femur won't makethe damage of pulmonary function more serious in the patient with thoracicinjury.Effect to infection : Some scholars think unreamed nailing have arelatively worse fixation and becteria can grew more easily in theintramedullary air `containing space remained. While reaming can not onlyincrease the stability of fracture but also decrease the dead space for the debrisafter reaming fill the space . Also there is different opinion : reaming can causethe increasing of the local infection rate because it destroys the blood supply ofendosteum. Some other scholars think whether reaming or not won't affect theinfection rate . The study showed : the deep infection after the intramedullarynailing fixation in the patient with open femoral fracture was close relatedonly with Gustilo typing ,and whether reaming or not did not have obviousdifference in statistics.Many infections after reaming are related with externalfactors such as technique in the operation which can be avoided. Some studiesshowed : in the closed fracture ,43.8% of deep infections were caused byincorrect fascia closing ,changing nailing and hot necrosis .in the openfracture ,62.5% of infections were related to the complications of advancedstage after plastic operations,in which the edge necrosis of skin flap was themost important factor .