Varus distal femoral osteotomy in young adults with valgus knee

<p>Abstract</p> <p>Background</p> <p>Musculoskeletal disorders specially knee osteoarthritis are the most common causes of morbidity in old patients. Disturbance of the mechanical axis of the lower extremity is one of the most important causes in progression of knee osteoarthritis. The purpose of the present study was to analyze the surgical results of distal femoral varus osteotomy in patients with genu valgum.</p> <p>Methods</p> <p>In this study, after recording history and physical examination, appropriate radiographs were taken. We did varus distal femoral osteotomy by standard medial subvastus approach and 90-angle blade plate fixation then followed the patients clinically and radiographically.</p> <p>Results</p> <p>This study was done on 23 knees (16 patients) age 23.3 years (range, 17 to 41 years). The mean duration of following up was 16.3 months (range, 8 to 25 months). Based on paired T test, there were statistically significant difference between pre- and postoperative tibiofemoral and congruence angles (p < 0.001, t = 21.3 and p < 0.001, t = 10.1 respectively). Pearson correlation between the amount of tibiofemoral and congruence angle correction was also statistically significant (p = 0.02 and r = 0.46).</p> <p>Conclusion</p> <p>Distal femoral varus osteotomy with blade plate fixation can be a reliable procedure for the treatment of valgus knee deformity. In this procedure, with more tibiofemoral angle correction, more congruence angle correction can be achieved. Therefore, along with genu valgum correction, the patella should be stabilized simultaneously.</p

Periprosthetic fractures of the femur after total knee arthroplasty

Periprosthetic fracture following total knee arthroplasty is a potentially serious complication. This injury can involve the distal femur, proximal tibia or the patella. This review article analyzes the prevalence, risk factors, classification and treatment options for periprosthetic fractures of the femur

Surgical training multiple letters

[No abstract available

Megaprostheses for well-fixed TKA femoral fractures

The use of distal femoral replacement (DFR) prosthesis is an option for treating distal femoral periprosthetic fracture (PPF). It is particularly helpful when the distal femoral bone is small and not amenable to rigid fixation. We report the results of 13 distal femoral PPFs at an average age of 77.5 years that were treated by this technique. At a mean follow-up of 30.5 months, the average Knee Society Score and functional score were 82 and 20, respectively. All patients who were ambulatory before fracture, regained their ability to walk after the surgery. There was a revision surgery for treating patellar instability. DFR is a reliable treatment for distal femoral PPFs with poor bone stock that allows for early ambulation in an elderly and low-demand group of patients. © 2015 Elsevier Inc

Rotating hinge knee causes lower bone�implant interface stress compared to constrained condylar knee replacement

Purpose: To compare the stresses at bone�arthroplasty interface of constrained and semi-constrained knee prostheses, using the finite element (FE) method as a predictor of the survivorship of the implants. Methods: Three-dimensional FE models of the knee implanted with rotating hinge (RHK) and legacy constrained condylar (LCCK) prostheses were generated to study the loads and stresses for two situations: medial- and lateral collateral ligament deficiencies in full extension. Results: On average, the shear stress developed at bone�implant interface dropped from 16.9 to 13.7 MPa (18.9), and the interface von Mises stress lowered from 37.6 to 30.2 MPa (19.6) in RHK compared to those in LCCK prostheses. RHK design also resulted in a more uniform stress distribution at the interfaces in both femur and tibia. The average polyethylene liner stress dropped from 9.6 to 2.6 MPa (a 72.7 decrease) in RHK design when compared to that in LCCK design. Conclusion: The more uniform interface stress suggests fewer density changes at the periprosthetic regions due to bone remodelling. Moreover, the lower polyethylene stresses are likely to reduce wear and damage. These findings reveal that the RHK design may have more favorable mechanical features compared to LCCK design in full extension boundary conditions, implying a potentially better survivorship. However, the findings should be interpreted cautiously as other configurations were not investigated. © 2018, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA)

Rotating hinge knee causes lower bone�implant interface stress compared to constrained condylar knee replacement

Purpose: To compare the stresses at bone�arthroplasty interface of constrained and semi-constrained knee prostheses, using the finite element (FE) method as a predictor of the survivorship of the implants. Methods: Three-dimensional FE models of the knee implanted with rotating hinge (RHK) and legacy constrained condylar (LCCK) prostheses were generated to study the loads and stresses for two situations: medial- and lateral collateral ligament deficiencies in full extension. Results: On average, the shear stress developed at bone�implant interface dropped from 16.9 to 13.7 MPa (18.9), and the interface von Mises stress lowered from 37.6 to 30.2 MPa (19.6) in RHK compared to those in LCCK prostheses. RHK design also resulted in a more uniform stress distribution at the interfaces in both femur and tibia. The average polyethylene liner stress dropped from 9.6 to 2.6 MPa (a 72.7 decrease) in RHK design when compared to that in LCCK design. Conclusion: The more uniform interface stress suggests fewer density changes at the periprosthetic regions due to bone remodelling. Moreover, the lower polyethylene stresses are likely to reduce wear and damage. These findings reveal that the RHK design may have more favorable mechanical features compared to LCCK design in full extension boundary conditions, implying a potentially better survivorship. However, the findings should be interpreted cautiously as other configurations were not investigated. © 2018, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA)