The Clinical Anatomical Research On Acute Angle In Posterior Cruciate Ligament Reconstruction Of Knee Joint

Objective:To explore the effect of femur tunnel position and knee flexion angle onacute angle in posterior cruciate ligament reconstruction.Materials and Methods:12fresh-frozen human cadaveric knees were dissected to mark posteriorcruciate ligament’s footprint center O1、O2,sulcus of medial epicondyle offemur A,distal beginning of vastus medialis’ center E,AE’s quarter pointsB、C、D.Take care of medial and lateral collateral ligament,do not hurtthem. All the things were measured at90°of flexion: the length of BO1、CO1、DO1、EO1, and line O1O2’s angle (l、γ).Arcs were made by differentlength,with the center O1.These arcs’ border and middle were markdewith F、G、H.Then measured γ of FO1、GO1、HO1.Measure γ of CO1indifferent knee flexion angle.Mark these point with steel ball,then take theknees’anteroposterior and lateral plain X-rays.Results:1、γ(B) and γ(C) had no statistical differences in paired-comparison, butγ(D)、γ(E) had（P＜0.05）. l was negative correlation with γ, thecorrelation coefficient is-0.518.2、In all specimens,most of all femur tunnel,eg.33mm、36mm、39mm femur tunnel can locate in the safe area except30mm and42mm femurtunnel.So we wipe of30mm and42mm femur tunnel. γ(F)、γ(G)、γ(H)had no statistical differences below36mm femur tunnel,but in39mm（P＜0.05）, γ（H）＞γ (F).3、 Flexion angle was negative correlation with γ.the correlationcoefficient is-0.999.All of them had statistical differences but γ(90°)between γ(120°).Conclusions:1、 The length of bone tunnel was negative correlation with thebone-graft angles.The longer the bone tunnel was,the smaller the angleswere.2、The position of bone tunnel had little influence on the bone-graftangles below36mm.The position of bone tunnel in39mm had obviousinfluence on the bone-graft angles,the angles of anterior point H werelarger than the posterior point F.3、The bone-graft angles varied with knee flexion angles.The more kneeflex,the smaller bone-graft angles were.The knee flexion angles hadobvious influence on the bone-graft angles during0°～90°,but littleabove90°.Above all,a bigger bone-graft angles can be made by a shorter femurtunnel or an anterior exit under inside-out technique with90°kneeflexion angles.Those may lead to a smaller acute angle.