Exact Solution for Phenomenon of atomic Collapse and Revival under Rotating Wave and Anti-Rotating Wave Approximation

An accurate method to solve the daynes Cummings （J-C） Hamiltonian has been investigated here. The phenomenon of atomic collapse and revival predicted by Jaynes-Cummings model is demonstrated. Solutions are consis- tent with the precious such as using the operator method. Furthermore, the Jaynes-Cummings Hamiltonian including the anti-rotating term is also solved precisely using this accurate way so that results agree with experiments better. Essences of the anti-rotating term are revealed. We discuss the relations of the phenomenon of atomic collapse and revival with the average photons number, the light field phase angle, the resonant frequency, and the size of coupling constant. The discussions may make one select suitable conditions to carry out experiment well and study the virtual light field effect on cavity quantum electrodynamics.

PFNA2 versus 95 Degree Condylar Blade Plate in the Management of Unstable Trochanteric Fractures

Purpose: The proximal femoral nail anti-rotation (PFNA) is known to have advantages in enhancing the anchorage ability of internal fixation in elderly unstable osteoporotic intertrochanteric fracture patients. However whether it is superior to condylar blade fixation is not clear. This study aimed to determine which treatment has better clinical outcomes in older patients. Materials and Methods: A total of 86 patients over the age of 60 with unstable trochanteric fractures within the past 3 weeks, were included in this prospective study conducted from June 1, 2018, to May 31, 2021. All the intertrochanteric fractures were classified according to AO/OTA classification. Among them, 44 cases were treated with the Proximal Femoral Nail (PFNA2) with or without an augmentation screw, and 42 cases were treated with the Condylar Blade Plate. In addition, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion, postoperative weight-bearing time, hospitalization time, Harris score of hip function, Kyle’s criteria and postoperative complications were compared between the two groups. Results: The mean duration of surgery for the PFN group was 66.8 minutes (on average), whereas for the condylar blade plate group, it was 99.30 minutes (on average). The PFNA2 group experienced less blood loss (average of 80 mL) compared to the condylar blade plate group (average of 120 mL). Union and partial weight-bearing occurred earlier in the PFNA2 group (14.1 weeks and 10.6 weeks, respectively) compared to the Condylar blade plate group (18.7 weeks and 15.8 weeks). In two patients from the PFNA2 group, screw backing out and varus collapse complications were encountered;however, these patients remained asymptomatic and did not require revision surgery. In two other patients, screw cut out and breakage of the nail at the helical screw hole leading to non-union of the proximal femur were observed during the nine-month follow-up, necessitating revision surgery with prosthetic replacement. Among the condylar blade plate group, three patients experienced complications, including blade breakage at the blade and plate junction. In two cases, the fracture united in varus, and in one case, the blade cut through, resulting in non-union of the femoral head, which required revision surgery. According to the Harris hip score and Kyle’s criteria, a good-excellent outcome was observed in 92.85% of cases in the PFNA2 group and 90.90% of cases in the condylar blade plate group. Conclusion: Both the Proximal Femoral Nail A2 and Condylar blade plate are effective implants for the treatment of unstable trochanteric fractures. The intramedullary implant promotes biological healing and allows for early ambulation with minimal complications. Similarly satisfactory restoration of anatomy and favorable radiological and functional results can be achieved with the biological fixation provided by the 95-degree condylar blade plate. However, the use of PFNA2 internal fixation technique has the advantage of less trauma in elderly patients than the 95-degree condylar blade plate.

Effect of proximal femur nail anti-rotation on unstable intertrochanteric fractures: A prospective observational study

Objective:To assess the effect of proximal femur nail anti-rotation on the functional and radiological outcome of unstable intertrochanteric fractures.Methods:This prospective observational study was conducted in the orthopedic department of a tertiary care hospital.Altogether 86 patients with unstable intertrochanteric fractures treated with proximal femur nail anti-rotation between January 2010 and January 2015 were included.Patients were followed in the outpatient clinic at regular intervals after discharge to assess the radiological union of fractures and complications.The functional outcomes were evaluated after 2 years by Harris hip score.Results:All patients achieved a radiological union of fractures after a mean duration of 24.6 weeks.The follow up showed 23 complications(systemic and local).Eight patients developed urinary tract infections,and three patients developed chest infections,two patients had screw cut-out,one patient had knee stiffness,one patient developed superficial surgical site infection,and four patients developed varus collapse and shortening subsequently.The two year follow up showed that 69(80.2%)patients had an excellent and good functional outcome according to Harris hip score.Conclusions:With lower complication rates,proximal femur nail is a valid and reasonable option especially in treating unstable intertrochanteric fractures.

Treatment of long-segment fracture in middle-up part of femoral shaft with long proximal femoral nail anti-rotation of AO/ASIF

Objective To investigate the operative method and evaluate the clinical outcomes of long proximal femoral nail anti-rotation (PFNA-long) in treating long-segment fracture in middle-up part of femoral bone.Methods From June 2006 to

A rare complication of pelvic perforation by an excessive medial slide of the helical blade after treatment of an intertrochanteric fracture with proximal femoral nail anti-rotation:A case report and literature review

Intertrochanteric fractures have become a severe public health problem in elderly patients.Proximal femoral nail anti-rotation(PFNA)is a commonly used intramedullary fixation device for unstable intertrochanteric fractures.Pelvic perforation by cephalic screw is a rare complication.We reported an 84-year-old female who fell at home and sustained an intertrochanteric fracture.The patient underwent surgery with PFNA as the intramedullary fixation device.Routine postoperative examination revealed medial migration of the helical blade that eventually caused pelvic perforation.We performed a cemented total hip arthroplasty as the savage procedure.At the latest follow-up of 12 months after total hip arthroplasty,the patient had no pain or loosening of the prosthesis in the left hip.Pelvic perforation should be considered when choosing PFNA as the intramedullary fixation device,especially in patients with severe osteoporosis wherein the helical blade can be easily inserted during the operation.The lack of devices to avoid oversliding of the helical blade in PFNA is an unreported cause of this complication and should be considered in such cases.

Medial support nail and proximal femoral nail antirotation in the treatment of reverse obliquity inter-trochanteric fractures(Arbeitsgemeinschaft fur Osteosynthesfrogen/Orthopedic Trauma Association 31-A3.1):a finite-element analysis

Background:The reverse obliquity inter-trochanteric fracture is a distinct fracture pattern that is mechanically different from most inter-trochanteric fractures and the optional treatment of it is still controversial.The purpose of this study was to compare differences in the efficacy of a novel nail(medial support nail[MSN-II])and proximal femoral nail anti-rotation(PFNA-II)in the treatment of reverse obliquity inter-trochanteric fractures(Arbeitsgemeinschaft fur Osteosynthesfrogen/Orthopedic Trauma Association[AO/OTA]31-A3.1)using finite-element analysis.Methods:Modeling software was used to establish a three-dimensional model of MSN-II and PFNA-II and an A3.1 inter-trochanteric fracture model.Abaqus software was used to implement different force loads to compare finite-element biomechanical parameters such as the maximum stress in implant and the displacement of fracture site.Results:The femoral stress,implant stress and fracture site displacement of MSN-II was less than that of PFNA-II.The results indicated that the maximal femoral stress was 581 MPa for PFNA-II and 443 MPa for the MSN-II.The maximum stress values in the PFNA-II and MSN-II models were 291 and 241 MPa,respectively.The maximal displacements of the fracture site were 1.47 and 1.16 mm in the PFNA-II and MSN-II models,respectively.Conclusions:Compared with PFNA-II for inter-trochanteric fracture(AO/OTA 31-A3.1),MSN-II which was designed with a triangular stability structure can provide better biomechanical stability.The MSN-II may be a feasible option for the treatment of reverse obliquity inter-trochanteric fracture.