Introduction

Junior level orthopaedic surgery residents who train with a virtual surgical simulator can lead to improved arthroscopy performance.

This is a report on the first 100 THR patients treated with an off the shelf version of a novel “Lateral Flare” femoral component. A prior published report has documented the up to 19 year follow up of custom fabricated stems of an identical design concept as being successful in patients < 55 years of age.

HHS, radiographic measure of bone morphology, implant stability and densitometric measure of bone response after THR with an off the shelf version, “Revelation Lateral Flare”, femoral component, confirm excellent bone preservation and implant stability with this design concept. DEXA analysis of a 20 consecutive patient subset of these 100 patients, documented preservation of more than 95% of proximal femoral bone stock in Gruen zone 1 and 102% of total bone stock in Gruen zones 1–7. Implant stability measurement documented < 0.5mm of subsidence in spite of patients being permitted immediate post-operative full weight bearing activity.

These findings support reasonable optimism for expectation of successful long term results being achievable with the use of an off the shelf version of the “Lateral Flare” design concept, in young, high demand patients suffering with early onset osteoarthrosis of the hip.

Uncemented porous coated femoral implants rely on bone in growth to achieve stable, long lasting fixation. The loss of proximal femoral bone mass around hip stems has been traditionally termed ‘stress shielding’ and has been linked to the transfer of loads to the diaphysis and the relative unloading of the proximal femur. Proximally loading devices should then minimize or avert stress shielding altogether. We prospectively evaluated the changes in the periprosthetic bone mass density after insertion of an off-the-shelf non-cemented stem designed to engage both cortices at the metaphyseal level.

A total of 10 total hip arthroplasties with a proximally coated lateral flare device were evaluated with dual-energy x-ray absorptiometry and qualitative radiographic changes 3 weeks after surgery and at 12, 24 and 52 weeks thereafter. The regions of interest (ROI) used in this study corresponded to the zones described by Gruen.

All hips were radiologically stable. The DEXA measurements revealed an overall increase in the BMD at 52 weeks of 4%. Greater gains were observed at or below the lateral flare of the stem in the metaphyseal femur.

The use of an extended proximally loading device proved to have a beneficial effect in the periprosthetic bone mass density due to its geometry and inherent primary stability evidenced by the DEXA and subsidence values.

Background: Over the past decade, several modifications have been introduced to uncemented femoral stems. The design of the stems, however, still classically fall under two categories: anatomical and straight. The purpose of this paper is to report the first clinical, radiographic and periprosthetic densitometry results of a cementless total hip arthroplasty performed with an off-the-shelf extended metaphyseal loading device

Fifty-eight consecutive patients who received aproximally loading non-cemented hip prosthesis were followed for an average of 4.4 years. Patients were clinically and radiographically followed at 3 weeks, 3 months, 6 months, 1 year and yearly thereafter. In addition, a group of 8 consecutive patients were studied with Dual X-Ray Absorptiometry Scans(DEXA) at the same intervals during the first year and at 18 months after surgery.

The extended proximal geometry of the device allowed for initial and secondary stability reflected by the low subsidence values over time. The maintenance of periprosthetic bone stock over time and the absence of stress shielding can be explained by the proximal loading pattern of the stem.

Thromboembolism following total hip arthroplasty is a common complication that may result in significant morbidity and mortality. Despite this, optimal prophylactic regimen is controversial. According to the literature, the prevalence of deep venous thrombosis during the early post-operative period ranges from 13% in patients utilizing low molecular weight heparin to 18% in patients treated with sequential compression devices alone.

We investigated the efficacy of a comprehensive approach encompassing the use of aspirin, intermittent compression devices (‘foot pumps’), and early mobilization in a cohort of 290 consecutive patients after non-cemented total hip replacements. The surgical procedures were carried out under epidural anesthesia in most cases (91%). All patients were allowed full weight bearing and received ambulation training starting on the first post-operative day. Ankle-high pneumatic boots (‘foot pumps’) were used early immediately surgery. Aspirin (325 mg po/qd) was used as a pharmacological measure to prevent thromboembolism. The presence of deep vein thrombosis was determined with the routine use of venous duplex scans on post-operative day number 5 to 10 (mean 6.8). The duration of the follow-up was 3 months. No patients were lost to follow-up.

Four distal DVT and two proximal DVT were detected in five patients (3%). None of the patients developed symptomatic pulmonary embolism during the follow-up period. There were no major wound complications.

Venous thromboembolic disease after hip replacement surgery is largely associated with postoperative immobilization and venous stasis. It is the authors’ opinion that a prevention strategy should include mechanical as well as pharmacological measures. The concomitant use of epidural anesthesia, “foot pumps”, aspirin and early full weight bearing ambulation may be effective in further reducing the incidence of DVT after surgery.