Tips and tricks of DHS Fixation

Dynamic Hip screw was first time designed by Pohland & Kiel in 1952.This implant from the 1980 to 2000 became the gold standard for pertrochantericfracture fixation because of many reports of failure in unstable hip fractures otherdevices especially cephalomedullary nailing was popularized in 2 to 3 recent decades.Despite important role of biomechanical effect of implant design, quality ofreduction is the most important factor that determines the patient out come manyclassifications was produced by autors but few of them that more practical fortreatment and outcome are Boyd & Griffin – Evans and Muller AO/OTA classification .AO/OTA classification is the most referenced in recent scientific articles and consist oftypes of stable and unstable FXS that unstable implies displaced and fix in unreducedposition, comminuted with destruction of anteromedial cortex and reverse obliquitypattern. expect of very few cases, operative treatment for hip FXS is standardtreatment, and the best time is within in 24 to 48 hours. Parker and Handoll reportedthat there is consensus regarding the superiority of the dynamic compression nailsor plate devices and results were equivalent at functional outcome measures andimplant mechanical failure rates and time of hospitalization. But literature hasrevealed certain fracture patterns which are not amenable to simple screw side platedevices, reverse obliquity fractures and fractures with lateral wall fracture extension.Though still the most used device around the world, the SHS is associated with twoserious complications uncontrolled collapse and migration of the lag screw withinthe femoral head leading to varus and possible screw cut out. The incidence of thisis increased in malreduced FXS or those with iatrogenic FX of the lateral wall andconstruct collapse.In intertrochanteric FX the anteromedial cortex is key stone of reduction and stabilityand every effort must paid to reconstruct this region.Adequate reduction is the major preventable etiology for lost reduction and constructfailure in pertrochanteric FX.In reverse obliquity FX pattern usage of DHS can result of early failure because offemoral medialization .and device of choice in this pattern of FX is cephalomedullarynailing .in FXS that can’t reduce closely , direct observation of FX with more extensileapproach such as Watson- Jones san help us to achieve of anatomic fixation . patientposition with FX table in supine position and usage of C.Arm is very helpful . thebest position of lag screw is center to center position with TAD<25 . provisionalfixation of reduction with 1 or 2 K wire advised . and like every other of condition,early ambulation of patient based on anatomic reduction and secure fixation candramatically reduce the complications.