Objective To explore the clinical efficacy of one-stage cannulated screw fixation in treatment of tibial avulsion fracture at the insertion of posterior cruciate ligament(PCL) under posterior direction version and in treatment of tibial avulsion fracture at the anterior cruciate ligament (ACL)under arthroscopy.Methods From January 2010 to June 2015,25 patients with tibial avulsion fractures of the posterior cruciate ligament combined with the anterior cruciate ligament in our hospital were retrospectively analyzed.Firstly,arthroscopic exploration was conducted in all patients in their horizontal position,aiming to observe whether combined injures existed or not and to confirm fracture fragments and the degree of tibial avulsion fractures of the cruciate ligaments.All patients recieved arthroscopic fragment fixation by using cannulated screws,then,were treated with a minimally posteromedial incision in the prone position by cannulated screw fixation.All knee joints were protected by adjustable orthopedic brace for 4-6 weeks.The clinical knee joint function of patients were measured by using International Knee Documentation Committee (IKDC) scoring scale and Lysholm scoring scale.The X-ray or CT image were used to evaluate healing process of the fractures.Results All patients were followed up for 6-24 months,the median follow-up time was 15 months.All fractures healed in one stage,time of fracture healing ranged from 9 to 24 weeks,and the median time was 12 weeks.The average IKDC scores at the finial follow-up were as follows:claudication (4.88±0.29)points,support (4.65±0.36)points,pain (4.78±0.49)points,swelling (4.88±0.52)points,squat (4.85±0.35)points,all were higher than those before operation,there were statistically significant differences when compared with those assessed before operation (P<0.05).The average Lysholm score at the finial follow-up was (93.4±2.8)points,the rate of excellent and fine was 96.0%,no statistically significant difference was found compared with that at the healthy side (P>0.05).Conclusion The one-stage cannulated screw fixation in treatment of tibial avulsion fracture at the insertion of PCL under posterior direction version and in treatment of tibial avulsion fractures at the ACL under arthroscopy is easy and convenient to operate,which has the advantages of reliable fixation and satisfactory recent curative efficacy.

Objective To study topological structure of a new type of three-dimensional (3D) printed height increasing insoles for leg length discrepancy (LLD) and its effect on biomechanics of lower limbs. Methods Topological structure for middle and rear part of the insole was optimized by solid isotropic microstructures with penalization (SIMP), the force was loaded and the boundary conditions were set according to force area of the insole, and the height increasing insole with thermoplastic polyurethanes (TPU) materials was printed by selected laser sintering (SLS). The insoles were used in 9 patients with LLD, visual analogue scale (VAS) and Maryland foot function scores were used to compare pain and foot function changes of patients before and after using the insole, and the 3D gait analysis system was used to compare spatiotemporal parameters and vertical ground reaction force (vGRF) of both lower limbs. Result sAfter the patient wore 3D printed insole, VAS scores decreased, Maryland foot function scores increased, vGRF of both lower limbs decreased, and the difference of cadence, stance phase and swing phase in both lower limbs decreased. Conclusions The 3D printed height increasing insole after topology optimization can improve coordination of lower limb movement, reduce ground impact, relieve pain and improve foot function, thus providing an effective personalized orthopedic plan for LLD treatment in clinic.