Application Of Greater Trochantic Tilting Index In Femoral Shaft Fractures In Closed Intramedullary Nail Surgery

Objective: As we all know that stripped of soft tissue may lead to theincrease of Healing rate and Infection in the treatment of long bone fractures.As minimal invasive theory develops and intramedullary nailing techniqueimproves, closed reduction and intramedullary nail insertion technique are themost common used treatment for femoral shaft fractures. However, thefractures are not exposed in closed reduction and its surroundings have a hugesoft tissue, It really difficult to determine the rotation reduction of the fracture.30%of mal-reduction rate associated with intramedullary nail ofproximal-third femoral fractures was reported by Ricci1. Severe femoralrotational deformity will inevitably lead to the biomechanics disorderhip ofhip and knee2,3, If this last for a long time, patients may suffer from traumaticarthritis which affect their daily lives. Therefore, it is always research focusfor all the scholars to find a method to judge mal-reduction of femoral shaftfractures.The Guochuan Zhang4proposed the concept of greater trochantic tiltingindex according to the relationship between the greater trochanter morphologyand proximal femur rotation state, did imaging measurements, and verified theformula of greater trochantic tilting index and proximal femur rotation anglewhich were used to determine the fracture rotation, But it was only feasible intheoretical, and had not been used in Clinical. So the purpose of this study isto assess the application of greater trochantic tilting index in femoral shaftfractures in closed intramedullary nail surgery.Methods: From January2011to January2012,64patients with Femoralshaft fractures were treated using Closed reset intramedullary nail fixation inour hospital,24cases were guided rotation by greater trochantic tilting index.The24patients,20cases of males and4females, aged from17to61years old, average age of36.5years. All cases were unilateral closed fractures,proximal-third femoral fractures13cases, femoral shaft fractures11cases;The left side14cases, The right side10cases. Fractures were classifiedaccording to the Russell-Taylor classification:7of typeⅠA,1of type II A,3of type ⅠB,2of typeⅡB; according to the AO/ASIF classification:11oftype32-2A,8of type32-2B,5of type32-2C. All fractures werecaused byhigh-energy trauma,11motor vehicle accident,8fall from height,5injured byheavy objects.11patients were associated with multiple-fractures,1acetabular fracture,2pelvic fracture,2lumbar fracture,3open ipsilateraltibiofibular frcture,2tibial plateau fracture,2bilateral talar fractures,1Threeankle fracture,1Galeazzi fracture and1clavicular fracture.9patientssuffered multiple-injuries,1eyes contusion,2face contusion,1knee skinlaceration,5chest wound. The greater trochantic tilting index was use in theoperation, C-arm X-ray machine filmed proximal femoral anteroposteriorimage, measuring the vertical distance between the protruding parts of themedial wall of the greater trochanter and the femoral shaft diameter, andcalculated the angle of rotation of the proximal femur and state. We usedifferent methods to reset fractures according to the calculation result. Whenthe proximal femoral external rotation≥15°, keeping the distal femur in aneutral position, using the internal rotation technology of Schanz pin to correctproximal femur and external rotation deformity; Proximal femoral externalrotation <15°,rotation the distal fracture according to the proximal angle ofrotation. Then locking the intramedullary nail and fixation of the fracture.Three days later after operation, Using CT to measurement bilateral femoralneck anteversion of patients, then did statistics analysis, At last, the differencebetween ipsilateral and contralateral anteversion was used to determine therotation reduction.Results: Application of greater trochantic tilting index shows:8casesexternal rotation more than15°, proximal-third femoral fractures7cases,femoral shaft fractures1cases;4cases external rotation10°-15°,proximal-third femoral fractures2cases, femoral shaft fractures2cases;12 cases external rotation less than15°, proximal-third femoral fractures4cases,femoral shaft fractures8cases;0case internal rotation. The maximumanteversion of the fracture sides was35.30°, the minimum anteversion0.50°,the mean value15.46°, and the standard error7.55°. The maximumanteversion of the contralateral side was31.20°, the minimum–6.1°, themean value14.29°and the standard error8.29°(P=0.053). The anteversionbetween fracture sides and contralateral side had no significant difference. Theaverage difference between fracture sides and contralateral side was2.17°, themaximum is8.2°, the minimum is0°.0case rotational deformity morer than10°. As it was shown in the Table1.Conclusion: With the application of greater trochantic tilting index infemoral shaft fractures in closed intramedullary nail surgery, the rotation angleand the status of the proximal femur are accurately determined, Improve thereset effect, and decreace the rate of mal-reduction. It is worth to be used inclinical.