ABSTRACT
Objective To evaluate biomechanical strength of locking compression plate (LCP) for fixation of periprosthetic proximal femur fractures (PPFF). Methods Eight matched pairs of Vancouver type B1 adult cadaveric PPFF specimens were fixed with the LCP and the inverted distal femoral less invasive stabilization system (LISS), respectively. Four bicortical locking screws (LCP group) and four unicortical locking screws were used to the length of prosthesis stem, and four double cortical locking screws were used to fix the distal end of the fracture in two groups, the distance from the locking screws to the fracture were also equal. The maximum bending load, maximum bending displacement, bending stiffness, maximum torque, maximum torsional angle and torsional stiffness of two groups in four-point bending test and torsion test were compared and analyzed. Results The maximum bending load, maximum bending displacement and bending stiffness of LCP group were all larger than those of LISS group, but the difference was not statistically significant (P>0.05). The maximum torque, maximum torsional angle and torsional stiffness of LCP group were obviously larger than those of LISS group，and there was a statistical difference between two groups (P<0.05). Conclusions The stiffness of anti-torsion with LCP is significantly better than that with LISS. Consequently, LCP has better biomechanical stability for PPFF.
ABSTRACT
Objective To evaluate the effect of anterior minimally invasive plate osteosynthesis (MIPO) for treatment of middle humeral shaft fracture.Methods From November 2011 to March 2014,10 cases of middle humeral shaft fracture were treated using MIPO via the anterior approach (MIPO group).Another 26 cases treated by open reduction and internal fixation (ORIF) of the middle humeral shaft fracture between October 2010 and March 2014 were included as controls (ORIF group).Fracture fixation using the 4.5 mm locking compression plate (LCP) was performed in both groups.Parameter measurements included operative time,intraoperative fluoroscopy times,grafting rate,intraoperative blood loss,postoperative drainage,hospital stay,bone healing time and complications.Results MIPO and ORIF groups differed significantly with respect to intraoperative blood loss [(93.5 ± 25.6) ml vs (325.3 ± 158.3) ml],intraoperative fluoroscopy times [(13.2 ± 6.1) vs 4.0 (0-6.0)] and hospitalization [(11.9 ± 1.7)days vs (18.0 ±4.7)days] (P ＜0.05).Bone grafting and drainage were not performed in MIPO group,while bone grafting rate was 54％ and postoperative drainage volume was (120.4 ± 69.6) ml in ORIF group (P ＜0.05).MIPO and ORIF groups were comparable with respect to operative time [(79.0 ± 22.0) min vs (97.5 ± 30.8) min],bone healing time [(15.2 ± 2.5) weeks vs (18.2 ± 4.8)weeks] and postoperative complications (10％ vs23％) (P＞0.05).Conclusion Anterior MIPO is an effective procedure for treatment of middle humeral shaft fracture,with advantages of small trauma,less bleeding,low risk of nerve injury and high rate of fracture healing.