AUSTIN MOORE PROSTHESIS IN THE MANAGEMENT OF FRACTURE NECK OF FEMUR IN AN ELDERLY POPULATION.

Introduction: Intracapsular fractures of the proximal femur form a major share of fractures in the 77 elderly. Hip replacement arthroplasty (partial or total) is emerging as a most viable treatment option, and in that, hemiarthroplasty with the Austin Moore Prosthesis is among the most commonly employed. In our study, we have made an attempt to assess the functional status at long term follow up after hemiarthroplasty with the AMP, used in the treatment of fracture neck of femur in the elderly population, and to substantiate the use of the prosthesis in modern day orthopaedic practice. Materials and : A retrospective study was carried out in patients above the age of 60 years, who had been diagnosed with non-pathological fracture neck of femur, treated operatively with hemiarthroplasty using the Austin Moore prosthesis in a tertiary care centre. A minimum follow up period of two years was considered. All the patients were evaluated clinically, and wherever possible, radiologically. Functional outcome was assessed based on the Harris Hip scoring system, and the results were analysed. Radiologically, an attempt was made to assess, among others, the amount of protrusio acetabuli at follow up, and femoral offset changes following hemiarthroplasty with the AMP. Results: In our study, we observed a positive functional outcome (excellent or good) in 9(45%) patients, with fair result in 6(30%) and poor in 5(25%). However, when pain alone was taken as criteria for assessment, upto 14(75%) patients had none to slight pain at follow up, and only 1(5%) patient had marked pain. Walking distance was significantly reduced in 6(30%) patients, who were either confined indoors or bedridden, but in only 1(5%) of them, the cause for the decreased ambulatory status was implant or procedure related (pain). Among the complications, 1 patient had a post-operative periprosthetic fracture that healed subsequently, 2 patients had marked osteolysis around the stem of the prosthesis, and only 1 patient had a radiological evidence of protrusio acetabuli. Discussion: Hemiarthroplasty with Austin Moore Prosthesis for fracture neck of femur remains a fairly good treatment option in elderly patients.

Probabilistic design strategy for improved Austin-Moore stem used in artificial cementless hip prosthesis considering material property uncertainty

Introduction. The use of probabilistic analysis is important when the input data are random, that leads to stochastic results. This paper describes the integration of a probabilistic design strategy of the solid and hollow stems implanted in a proximal femur in order to compare their advantages. The used hollow stem is called “Improved Austin-Moore” (IAM) model. Materials and Methods. Probabilistic methods allow variations in factors which control the biomechanical effects of the implanted femur to be taken into account while determining its performance. Different material properties were generated randomly using Monte Carlo simulation (MCS). Monte Carlo sampling techniques were applied, and different von Mises stresses of the layers (bone and metal) were chosen as a performance indicator. Results. A simple 2D implant-bone study of solid and IAM stem design was carried out with a high level of confidence, 99.87%, which corresponds to a target reliability index with regard to statistical uncertainties. The probabilistic design results show that the input and output parameters for the IAM stem are highly correlated relative to those for the solid stem. Discussion and Conclusions. The sensitivity analysis shows that the input parameters for the IAM stem play a much larger part in the output parameters relative to the solid stem. The IAM stem is much more advantageous than the solid stem which causes an increase in the performance of the hip prosthesis.

Anestesi Pada Pasien Dengan Penyakit Jantung Koroner Yang Menjalani Operasi Hemiarthroplasty

Seorang perempuan usia 76 tahun didiagnosis dengan Closed Fracture Collum Femur Dextra, direncanakan operasi Hemiarthroplasty Femur Dextra (Austin-Moore Protesa). Pasien dengan komorbid hipertensi tidak terkontrol dan penyakit jantung koroner, serta mendapatkan terapi antitrombolitik (Aspilet) rutin. Pada kasus ini kami melaporkan penggunaan anestesi regional teknik kombinasi spinal epidural untuk mengakomodasi prosedur operasi, serta manajemen perianestesi yang perlu diperhatikan untuk kasus ini.

Evaluating the performance of hollow stems used in total hip replacement by 3D finite element analysis

A 3D finite element analysis is carried out to evaluate the performance of our different developed hollow stems compared to the classical solid one. The hollow stems were developed considering the topology and shape optimization. Three types of optimized hollow stems were provided: KAD (Kharmanda-Antypas-Dyachenko) stem with a single hole, OAM (Optimized Austin-Moore) stem with double holes and IAM (Improved Austin-Moore) stem with three holes. A multi-objective formulation was developed as a performance scale for all kinds of studied stems (solid and hollow). This study is carried out according to the daily loading cases and considering that all used components (ball, stem, cortical and cancellous) are assumed to be made of isotropic and homogeneous materials. In the numerical applications, it is first shown the significant advantage of the three hollow stems compared to the solid one considering a performance function scale. Next, when comparing all hollow stems (KAD, OAM and IAM) in details, it is shown that the KAD stem for the daily loading cases, leads to the most homogeneous von-Mises stress distribution in both cortical and cancellous tissues.

Results of Conversion from Failed Austin-Moore Hemiarthroplasty to Cementless Total Hip Arthroplasty in Octogenarian Patients with Advanced Acetabular Erosion: A Minimum of 5 Years of Follow-Up

Austin-Moore hemiarthroplasty (HA) had been selectively used for elderly patients with femoral neck fractures. With increasing life span and activity, the sequela of Austin-Moore HA make the implant no longer favorable. The treatment of failed Austin-Moore HA with advanced acetabular erosion is challenging; however, little has been published regarding this topic. The aim of this study was to evaluate the mid-term results of using cementless total hip arthroplasty (THA) in octogenarians. Between 2008 and 2011, 47 patients (32 women and 15 men) with an average age of 86 years (range 83-89 years) were enrolled in this retrospective study. After an average follow-up period of 6.2 years (range 5.0-7.8 years), no migration or loosening of the cup or femoral stem was found. Harris hip scores improved from 36 (range 15-42) preoperatively to 87 (range 80-90). There were no complications directly associated with the procedure except for superficial infections in two patients. Our results suggest that using cementless THA can result in favorable radiographic and clinical outcomes in octogenarian patients.