Downsizing and minimising medialisation of the acetabular component: Novel technique to preserve bone in THA.

Standard practice for acetabular component placement in total hip arthroplasty (THA) is to medialise the acetabular component. Bone preservation techniques during primary THA are beneficial for possible future revisions. The goal of this study is to examine the effect of downsizing and minimising medialisation of the acetabular component on bone resection volume. The volume of bone resected during acetabular preparation for different sizes of components was calculated and the volume of bone preserved by downsizing the cup was determined. Minimising medialisation of the acetabular component by 1-3 mm from the true floor was calculated. Absolute values and percentage of bone volume preserved when acetabular components are downsized or less medialised is presented. Downsizing the acetabular component by one size (2 mm) preserves between 2.6 cm3 (size 40 vs 42) and 8.4 cm3 (size 72 vs 74) of bone volume and consistently reduces resected bone volume by at least 35% (range 35.2%-37.5%). Similarly, reducing medialisation of a 56 mm acetabular cup (as an example of a commonly implanted component) by 3 mm reduces bone loss by 5.9 cm3- 44% less bone volume resection. Downsizing and minimising medialisation of the cup in THA substantially preserves bone which may benefit future revision surgeries. Surgeons could consider implanting the smallest acceptable acetabular shell to preserve bone without compromising on head size.

Neck of Femur Fracture in Young Patients With End-Stage Renal Disease and Hyperparathyroidism: A Report of Three Cases and Proposed Treatment Algorithm.

Secondary hyperparathyroidism is a complication arising from untreated end-stage renal disease (ESRD). It can invariably lead to osteoporosis and subsequently cause pathological neck of femur (NOF) fracture. Despite being young, osteosynthesis in neck of femur fractures of these patients often leads to nonunion and implant failure due to severely osteoporotic bone. We present our experience in managing three young patients with ESRD and secondary hyperthyroidism who sustained NOF fractures. All three patients were successfully treated and showed no complication at one year post-operation. Based on our experience and literature review, we propose a simple algorithm to guide the management of these patients.