Titanium Elastic Nails for Pediatric Femur Fractures: Clinical and Radiological Study

Background: Management of femoral diaphyseal fractures in the age group 6-16 years is controversial. There has been a resurgence worldwide for operative fixation. Material and methods: Twenty children (15 boys, 5 girls) aged 6-16 years with femoral diaphyseal fractures (20 fractures, one in each) were stabilized with Titanium Elastic Nail (TEN). Patients underwent surgery within ten days of their injury. The results were evaluated using Flynn’s Scoring Criteria.Two nails were used in each fracture. Results: All 20 patients were available for evaluation and follow up for a mean duration of 24 months (15-32 months). Radiological union in all cases was achieved in a mean time of 8 weeks. Full weight bearing was possible in a mean time of 10 weeks (8-12 weeks). The results were excellent in 14 patients (70%) and successful in 6 patients (30%). Few complications that occurred were infection (in 2 cases), knee joint stiffness (in 4 cases), angulation less than 10 degrees (in 4 cases), shortening less than 10 mm (in 4 cases). Conclusion: Intramedullary fixation by TEN is an effective treatment of fracture of femur in properly selected patients of the 6-16 years age group.


Introduction
Femoral shaft fracture is an incapacitating injury in children [1,2].The treatm ent h as trad itionally b een ag e related, influenced by the type of injury, associated injuries and the location and type of fracture.
The aim of fracture treatm ent is not only anatomical realignment, bu t also restoration of m uscle an d joint function as close as possible to the normal.Psychological recovery is accelerated by early resumption of functional activity, which encourages healin g o f fract ure, maintenance o f normal ci rculation, preservation o f t one of t he muscles an d resto ration of t he m ovements of t he joints.The aim there fore is ea rly mobilization by earl y use o f the injured part without movement at the fracture site.
Because of rapid healing and s pontaneous correctio n of angulations most of femoral shaft fractures in children younger t han six y ears o f a ge ca n be t reated co nservatively.Above six years of a ge all suc h fractures whe n treated non -operatively co uld h ave lo ss o f reduction, malunion, i ntolerance a nd c omplication associ ated wi th plaster.Near the end of skeletal maturity accurate reduction i s nece ssary as a ngular deformity i s no l onger c orrectable by growth.In skeletally mature adolescents, use of an an tegrade so lid lo cked intramedullary n ail has be-come the standard of treatment.
In patients between 6-16 years of age there has bee n a tendency t owards operative approach.Ti tanium El astic Nailing (TEN) which is variously known as elastic stable intramedullary nailing (ESIN), has becom e the choice of stabilization in pediatric long bone fract ures, particularly the fe moral sh aft fracture.The present study is a imed at the ev aluation o f in tramedullay fix ation with TEN in children with fe moral fractures.Until recently skeleta l traction and application of a cast was the preferre d method o f t reatment of diaphyseal fem oral fract ures i n children and y oung adolescent.The devi ce would exploit a child's dense metaphyseal bone, rapid healing and ability to remodel without risking damage to the epiphysis or the blood supply to the capital femoral epiphysis.

Material and Methods
Twenty children (15 boys and 5 girls) in the age group of 6-16 years (average 10.8 years) with femoral shaft fracture were stab ilized with TEN from April 2007 to October 2009.T he pre dominant m ode of i njury was d ue t o fall f rom hei ght ( 50%).R ight-sided i nvolvement was seen in 13 cas es (65% ) a nd left side in 7 cases (35%).Mid-diaphyseal f racture of femur was found in 70 % of cases a nd s ubtrochanteric fracture in 30% cases.About 50% of the patients underwent surgery within 10 days of their injury.T he surgery ha d been carried out in the Department of Orthopaedics, Darbhanga Medical College & Hospital, Laheriasarai, Darbhanga, Bihar, India.
Nail comes in five diameters from 2.5 mm to 4.5 mm in a fi xed length.The nails are co lour coded for identification.The nails (Figure 1) are straight except for a bent tip.Sp ecial in struments in clude radiolucent redu ction tool, nail hol der, nail ben der, In sertion device, nai l extractor, wice grip and a nail impactor were used.
All th e p atients treated with TENs had skin/skeletal traction for approximately 1 week.As is the policy of our institution the traction pin (4.76 mm threaded Steinmann Pin) wa s i nserted i n t he operating room un der l ocal a naesthesia.The Pin was i nserted in th e reg ion of tib ial tuberosity an terolateral to posteromedial p lane.So me patients were stabilised wit h sk in traction .Co mpound fractures were pri marily t horoughly deb rided an d upper tibial skeletal traction applied.The injured limb was put on a Bohler's-Brawn splint and adequate weight applied.This is essen tial to minimize p ain, m uscle sp asm an d shortening.App ropriate tetanus proph ylaxis, antibiotics and an algesics were i nstituted.In t he p eriod of rest and resuscitation, th e patient was prop erly inv estigated and examined.As soon as t he pa tient becam e f it for a naesthesia an d su rgery h e/she was po sted for fixation of femoral sh aft fr actures with TEN.Good pr eoperative X-ray ( Figure 2) of th e injured femur was u sed to estimate th e n ail d iameter an d to de velop a n approach t o supplement fixation and plan the incision.
Half an h our bef ore ope ration 1 ampoule of atropine was g iven i ntramuscularly.In travenous line was setup .Prophylactic an tibiotic 1 gm ceftriax one was g iven intravenously. 1 am pule perinorm was given i ntramuscularly.Gene ral/spinal (a bove 14 y ears) a naesthesia was given with fu ll asep tic and an tiseptic precautions on an image intensifier (IITV) compatible operation table.
As soon as anaesthesia was effective, the patient was placed supine and upper tibial skeletal traction pin was removed with aseptic and antiseptic precaution.The patient was plac ed on radi olucent fracture ta ble.T he lim b was prepared and draped to give access to the entire femur and knee joint and to permit manual manipulation of  the th igh.Th e i mage in tensifier was p laced so t hat on e could get antero-posterior and lateral view of the femoral shaft.The monitor was placed in such a way that surgeon could have cl ear vision w hen i nserting t he nai l a nd reducing the fracture.
The sel ection of the insertion poi nt fo r the nails was medial and lateral at the top of the flare of the medial and lateral condyles so that after insertion they would tend to bind a gainst t he flare of the condyles.If the nails are inserted t oo low, th ey will t end to backout, wh ich is a troublesome c omplication.In add ition, t he in sertion should be posterior to mid line of th e shaft so that if th e nails b ackout, they w ill b e less lik ely to en ter th e synovial pouch.
A 5mm incision was made on the lateral side of the leg extending a bout t wo fi nger breadth ab ove t he s uperior pole of the Patella.(The superior pole of the p atella lies slightly above the level of the physis).A gu ide wire for 6.5 mm cannulated scre w was pas sed at 45 degrees angulation at the level of the superior pole of the patella.Over this a drill hole was made with the cannulated drill bit.Usi ng a cur ved bo ne awl, t he hole is ex tended cephalad to elongate the hole an d avoid cr acking of t he cortex when t he rod is inserted.The m edial entry hole was si milarly el ongated using a c urved b one a wl i n cephalad direction.The diameter of nail should be 2/5 of the internal diameter of t he m edullary canal (Nail diameter = 0.4 x Canal diameter).
Ideally, the lateral nail sho uld ex tend to t he lev el of the greater trochanter and the medial nail into the femoral neck.The amount of prebending should be equal for both t he nails.(The amount of bending s hould be t hree times the inner diameter of the shaft).Both the nails were inserted t hrough t he ent ry holes one a fter an other an d were driven up to th e fracture site.Th e red uction was helped by the use of F-tool which is a radiolucent device.The arms of the F-tool were readjusted depending on the fracture configuration and bulk of thigh viewing with the image intensifier.This nail was advanced about 2 cm and then rotated.At t his point, it was ad vanced f urther by rotating th is nail.Furth er red uction of the fract ure was accomplished and then the second nail was advanced.
The traction was released and bo th nails were advanced t o th eir fu ll leng th.Rotational an d ang ular m alreductions were che cked a nd i f present t he sam e was corrected by partially with drawing th e nails, correctin g the d eformity and rei nserting th e n ails.When t he nail was at its final po sition, it was m arked with a pen or clamp ab out 10 to 20 mm fro m th e in sertion hole.Th e nails were cu t at th e marked level an d adv anced so th at they lay agai nst the s upracondylar flare of the femur in order to avoid complications at the insertion site.
A knee immobilizer or controlled motion brace should be used for additional support.The patients were advised to perform movements at th e kn ee jo int and t hree po int touch d own e xercise t he day aft er su rgery un der t he guidance of a physiotherapist.When early callus formation is observed, weight bearing can be increased.External support can be discontinued when radiographic healing is co mplete.It is im portant th at the patients bear weight beca use t his provides t he m otion at t he fracture site that leads to early callus formation.In all cases postoperative x-rays an tero-posterior an d lateral v iews were taken.In th e po st-operative period p arenteral an tibiotics were continued for 5 days and then oral antibiotics were given till stitch removal.Along with an tibiotics, haematinics, serratiop eptidase, Calciu m, multivitamins were given.Stitches were rem oved on th e 12 th post-operative day.After remo val of stitch by 13 th to 14 th day post-operative patients were discharged.
Patients underwent regular follow up in the out patient department for clinical and radiological evaluation in the immediate post-operative period (Figure 3), at 4 weeks, 8 weeks (Figure 4), 12 weeks (Figure 5), 24 weeks , 35 weeks or till the publication of this series, whichever was earlier.

Results
The median duration of t he surgery was 80 min (60-120 min).All 20 patients were available for evaluation after a mean of 2 4 months (15-32 months) of f ollow-up.All patients were encoura ged t o do hi p and k nee no nweight bearing exe rcises from first post-operative day.W eight bearing was allowed according to the fracture geography and fixation.At the end of 1 st post operative week all patients were made ambulatory on crutches allowing weight bearing according to the qua lity of fixation.By 8 th week all th e p atients were bearing weight with only 2 p atients with touch-down weight bearing.Out of 20 cases, 2 cases complained of pain and irritation of sk in at th e entry site, associated with the prominence of the ends of the nails.
Out o f 2 0 cas es, 10 m m (1 cm ) short ening was observed in 4 cas es.These were among the earlier cases of the series and with comminuted fractures.Out of 2 0 pa-tients, 3 pat ients showed 1 0 degree or less angulation in the l ateral pl ane and o ne p atient had an eight degree angulation i n t he ant eroposterior plane.No br oken nails were observed in any of the 20 cases.Out of 20 cases, 2 opening the entry site.These patients had to undergo knee physiotherapy again and regained movements at the knee.No re-fracture was observed in the 2 cases that underwent   nail removal.

Discussion
In the present series TEN was used as a mode of fixation in different types of femoral fractures in children between ages 6 to 16 years.20 cases were treated a nd evaluated radiologically, clinically and functionally for the efficacy of TEN.In our series results were excellent in all 20 cases.Heinrich et al. (1994) reported that 22% of their patients had an ext ension over 5 m m, and 11% had a shortening under 5 m m.I n a st udy com paring se veral m ethods i ncluding TEN t he maximum shortening was observe d i n the early casting group followed by external fixator group where as lengthening was observed only in the external fixator gr oup.In o ur st udy o nly 4 cases showed 1 cm shortening which was clinically indiscernible.Herndon et al. (1 989) re ported t hat m alunion de veloped i n seven of 24 patients who were t reated wi th t raction while no malunion was observed i n 21 chi ldren w ho were t reated using TEN.
In a st udy co mparing ant erograde vers us ret rograde TEN by Galpin et al. [6] it was repo rted that 35 out of 37 patients had excel lent im provement i n t erms of angul ar deformity.We had angulation less than 10 degree towards varus/valgus or antero/posterior only in 4 patients (20%).In o ur seri es union pr ogressed sat isfactorily i n all 20 cases.At the end of 8 wee ks, 14 cases s howed fair to good cal lus fo rmation w hile 6 cases had m inimal call us formation.No bone grafting was requi red in any of t he cases.No significant malunion was observed in any of the 20 patients.Flynn et al. ( 2002) f ound TEN adva ntageous o ver hip-spica i n t reatment of fe moral shaft fractures in children.Buechsenschuetz et al. [7] doc umented TEN t o be superior i n t erms of uni on, scar form ation and overal l patient satisfaction when compared to traction and casting.Ligier et al. [8] treated 123 fe moral shaft fractures with TEN.All fract ures united with excel lent l ong t erm outcome.Similarly Narayanan et al. (2004) found TEN to be a very p romising m odality of fracture m anagement i n children.In our series of 20 cases, in 2 cases im plants were removed after complete union.
In the present series, by the time stitches were removed all 20 cases coul d do straight leg raising exercises.At the end of study period 15 patients (75%) could do full range of motion at knee joint.
All p atients w ere en couraged to do h ip and kn ee no nweight bearing exercises from first post-operative day.At the end of 1 st p ostoperative week all p atients were m ade ambulatory on crutches, allowing weight bea ring according to the quality of fixation.Flynn et al. (2002) used a knee fixating device to control the pain, to support quadriceps and to prevent the end of nail cau sing an y so ft tissue irritat ion in the kn ee un til the callus tissu e appears (4-6 weeks).The patients were able to walk on day 9 on an av erage with th e help of equipment an d at week 8.5 on avera ge wi thout t he equipment.In our seri es pat ients were m ade am bulatory on crutches after 1 st p ostoperative week .Partial weig ht bearing was al lowed at 6 weeks (ra nge 4-8 weeks) and full weight bearing was allowed at 10 weeks (Range 8-12 weeks).
The resu lts of th e p resent series are c omparable to those of the other series on management of femoral shaft fracture i n chi ldren.It has definite a dvantages o ver t he other co nventional i mplants t hat hav e bee n use d i n t he management o f pediatric fractures.N otable ad vantages of this technique a re early union due to repeated micromotion at fracture site, early m obilization, early weigh t bearing, sca r acceptance, eas y m anipulation i nvolved in implant rem oval and hi gh p atient sat isfaction rate.B esides these, unlike other implants TEN does not endanger either the epiphysis or t he blood supply to femoral head.The excellent biocompatibility and elasticity of titanium have further enhanced the virtues of TEN.High grade of elasticity o f tit anium li mits the de gree a nd perm anence of de formation t hat t he nail undergoes d uring i nsertion.More importantly elasticity promotes callus formation by limiting stress shielding.
Table 1 shows important aspects of th is study like age and sex of the patients, nature and mode of injury, specifications of nail u sed, fo llow up results an d du ration, surgical complications like intraoperative blood loss and others.
The bi omechanical pri nciple of TEN i s based on t he symmetrical bracing action of two elastic nails inse rted into th e metaphysis, each of which bears ag ainst th e inner bone at three points.This biomechanics helps in achie-  ving a high grade of stability i.e. flexural stability, axial stability, translational stability and rotational stability.

Conclusions
The i ntramedullary fix ation b y TEN is a m ethod of choice due to its distinct advantages over other c onventional modalities.Easy manoeuvering, excellent outcome, lower incide nce of c omplications a nd ea sier postoperative m aintenance have m ade T EN t he most pru dent, practical and successful intervention in the management of femoral shaft fractures of pat ients bet ween 6 and 16 years of age.

Figure 1 .
Figure 1.TEN with different length and diameter.

Figure 3 .
Figure 3. Immediate postoperative x-ray of femur (AP and Lat view).

Figure 4 .
Figure 4. 8 th week postoperative x-ray of femur (AP and Lat view).

Figure 5 .
Figure 5. 12 th week postoperative x-ray of femur (AP and Lat view).