ABSTRACT
Objective:To explore mechanical stability of Proximal Humeral Internal Locking Plate System (PHILOS) in the treatment of Vancouver B1 femoral periprosthetic fractures by three-dimensional finite element analysis.Methods:A three-dimensional finite element model of the femur was established by digital medical software (Mimics 21.0, 3-matic12.0, Geomagic12.0 and Hypermesh 2017.0) using the CT data of a femur from a volunteer (male, 34 years old, 173 cm in height and 65 kg in weight). After the femoral trochanter was cut in the femoral models, a femoral stem was implanted. PHILOS fixation (PHILOS group) and Cable-Ready GTR fixation (Cable group) were applied respectively. Loads of 700 N, 1,400 N and 2,100 N were applied to the 2 groups of finite element models. Distributions of Von Mises stress and deformation were investigated in the finite element models of 2 internal fixations; the mechanical stability was compared between the 2 groups of models.Results:The maximum deformation occurred on the femoral ball head in the 2 groups of models. At the load of 2,100 N, the maximum deformation was 3.77 mm in the PHILOS group, larger than 3.58 mm in the Cable group, and the maximum stress peak value in the PHILOS group was 491.54 MPa, about 49.2% lower than that in the Cable group (733.61 MPa). The peak stress in the PHILOS group was mainly distributed on the 4th and 5th fixation ends at the bone plate while the peak stress in the Cable group was mainly distributed on the second titanium cable under the fracture line.Conclusions:Under various loads, both PHILOS fixation and Cable-Ready GTR fixation can provide sufficient mechanical stability. As the peak stress of PHILOS fixation is much lower than that of Cable-Ready GTR fixation, PHILOS can be used as an effective fixation method for Vancouver B1 femoral periprosthetic fractures.
ABSTRACT
Objective:To evaluate the clinical efficacy of high tibial osteotomy(HTO) plus arthroscopic surgery in the treatment of medial gonarthrosis.Methods:From January 2017 to May 2018, 40 patients were treated at Department of Joint Orthopaedics, Wujin Hospital Affiliated to Jiangsu University and at Department of Joint Orthopaedics, The First Affiliated Hospital to China Medical University for medial gonarthrosis. They were divided into 2 groups according to their different treatment methods. Group A was treated by HTO plus arthroscopic surgery; there were 20 cases, 8 males and 12 females with an age of 59.7 years ± 5.5 years. Group B was treated by only HTO; there were also 20 cases, 10 males and 10 females with an age of 58.2 years ± 4.3 years. The 2 groups were compared in terms of Hospital for Special Surgery (HSS) knee score, visual analogue scale (VAS), hip knee ankle angle (HKA), medial proximal tibia angle (MPTA) and posterior tibial slope angle (PTSA) at 6, 12 and 24 months postoperatively and at the last follow-up.Results:The 2 groups were comparable because there were no significant differences between them in the preoperative general data ( P>0.05). The HSS and VAS scores at 6 months after operation in group A (82.7±2.4 and 1.7±0.7) were significantly better than those in group B (78.4±2.6 and 2.2±0.8) ( P<0.05); the HSS score at 12 months after operation in group A (88.1±1.8) was significantly better than that in group B (82.9±1.7) ( P<0.05). There were no significant differences between the 2 group in the VAS score at 12 months after operation, or in the HSS or VAS scores at 24 months or at the last follow-up ( P>0.05). There were no significant differences either in the HKA, MPTA or PTSA scores between postoperative 6, 12, 24 months and the last follow-up ( P>0.05). Conclusion:In the treatment of medial gonarthrosis, high tibial osteotomy plus arthroscopic surgery may lead to better short-term outcomes than high tibial osteotomy alone, but the 2 methods may result in similar curative efficacy by 24 months after surgery.