Introduction

Gaucher Disease (GD) is the commonest of the lysosomal storage disorders. Orthopaedic manifestations occur in 90% and include osteonecrosis of the femoral head, often producing severe disability at a young age. Historically, arthroplasty has been avoided in GD due to high reported rates of haemorrhage and decreased implant survival. The advent of enzyme replacement therapy (ERT) has revolutionised GD treatment with correction of haematological parameters within five months. However there is little data regarding the effect of ERT on the outcomes of hip arthroplasty.

Introduction

We present the outcome of 297 acetabular revisions using bone grafting and cemented acetabular components in 297 patients, with a mean follow-up of 8 years 3 months (5–20 years).

Background: Since Sir John Charnley introduced bio-clean air operating techniques such as the “body exhausting” system and a bio-clean air operating theatre to reduce the risk of infection3), total hip replacement has become one of the safest and most successful procedures in orthopaedic surgery and has benefited numerous people suffering from arthritis all over the world. However, deep infection is still undoubtedly one of the most serious complications after total hip arthroplasty (THA). It is still controversial whether one or two stage revision should be indicated for deeply infected hip replacement.

Purpose: The aim of this study was to identify the influential factors in one stage revision THA for deep infection with a long-term follow-up.

Methods: One stage revision THA for deep infection was carried out in 273 joints on 262 patients by the senior author between 1974 and 2000. All infected hip replacements were primarily treated with one stage revision THA regardless of micro organisms at the authors’ unit as far as sufficient bone stock for socket fixation was available in the acetabulum. This study included 162 revisions in 154 patients for which a minimum follow-up of five years (range 5 to 28 years; average 12.3 years) had been done. Fifty-two cases (32.1 %) had had discharging sinus by the time of revision surgery for infection.

Results: One hundred and thirty eight (85.2 %) hips were free of infection at the time of the latest follow-up. Twenty cases (12.3 %) had reoperation for recurrent infection. Four hips (2.5 %) maintained their implants with the evidence of infection. Twenty-two cases (13.6 %) showed radiological loosening. Thirteen cases (8.0 %) were revised again for reasons other than infection (12 for aseptic loosening and one for dislocation). Bone stock did not have significant influence on infection control while it did affect mechanical outcome. The cement-bone interface was an affecting factor for not only the mechanical survival of implants but also the cure of infection. Neither discharging sinus nor gram-negative microorganism was considered as a contraindication.

Conclusion: This study presented the longest follow-up with a large number of cases in revision THA for deep infection. The results suggested that shielding medullary space with antibiotic-loaded cement was important for treatment of infected THA.

One of the most serious complications of THA is deep infection.

Charnley realised the problem. This led to the development of clean air enclosure, total body exhaust suits and the introduction of the instrument tray system. Subsequently antibiotics were used both systematically and also as an addition to the acrylic cement. Occasional deep infection requires further intervention, either by removing the implant, or performing one or two stage revision. It has been the senior author’s practice to undertake one-stage revision provided the bone stock was of sufficiently good quality to ensure reasonable quality of component fixation. The technique is based on the accepted principle of infection management: Removal of all foreign body material and infected tissues, application of local antiseptics/antibiotics, closure of cavities, ensuring stability, drainage, rest, continuation of antibiotics.

Between January 1974 and December 2001, 185 one-stage revisions were carried out by the senior author: 162 had a minimum follow-up of 5 years with a mean of 12.3 years (5.1–27.6 years). 138 cases (85.2%) were free from infection. Presence of a sinus at revision did not affect the outcome adversely – on the contrary – 90.4% were infection free as compared with 82.7% of those without a sinus.

Attention to detail was the essential part of the operation.

The Triple-tapered cemented polished C-Stem has evolved from the study of long-term results of the Charnley low-frictional torque arthroplasty when the first fractured stem and then proximal strain shielding of the femur and stem loosening were identified as the continuation of the same process- the lack or loss of proximal stem support.

The concept, design and the surgical technique cater for a limited slip of the C-stem within the cement mantle transferring the load more proximally. With a follow-up past 12 years and 4063 primary procedures there have been no revisions for aseptic stem loosening and no stem is radiologically loose.

We have reviewed 1008 primary C-Stem hip arthroplasties performed by 23 surgeons with a minimum of 5 years clinical and radiological follow-up. The mean follow-up was 7 years (range, 5 – 12) and the mean age at surgery was 57 years (range (15 – 85). In 58% the underlying pathology was primary osteoarthritis, 20% congenital dysplasia, 10% quadrantic head necrosis, 5% rheumatoid arthritis, 5% slipped upper femoral epiphysis and 4% protrusio acetabulae.

The concept of the triple tapered stem is validated radiologically with an improved proximal femoral bone stock in over 20% of cases and a maintained bone stock in 60%.

There were no post-operative complications within 1 year in 87% and no late complications (after 1 year) in 91%. The main late complications were 3.9% aseptic cup loosening, 1% infection and 0.8% dislocation. There were no aseptic loose stems.

Twenty-eight hips have been revised (2.8%), 3 for infection, 2 for dislocation and 23 for aseptic cup loosening. There were no revisions for aseptic stem loosening.

The results support the concept but place a demand on the understanding of the technique and its execution at surgery.

The product recall of Desmarquest Zirconia heads in 2001 was associated with specified batches of material. Despite of this fact, concerns raised over the stability of Zirconia led to a vast decrease in the use of Zirconia for hip prostheses. While there is evidence in the literature suggesting that Zirconia may become unstable, there remain many prostheses with Zirconia heads in use today. The purpose of this study was to report the condition observed in retrieved Zirconia heads not included in the product recall.

The bearing surfaces of seven retrieved 22mm diameter Zirconia on UHMWPE hip prostheses were investigated to determine whether any degradation of the Zirconia occurred in-vivo. All seven of the Zirconia heads were manufactured by Saint-Gobain Cerammiques Avancees Desmarquest and implantation time varied from 1 to 10 years. Components were analysed by Talysurf, Interferometer, SEM and XRD and compared to new components.

Talysurf of the components revealed an average surface roughness ranging from 0.004 to 0.007 micrometers Ra. This was only slightly rougher than new ceramic components which generally have an Ra of 0.003 micrometers. SEM of the surfaces did not reveal any difference between the retrieved components and new components. Further surface XRD of 4 of the 7 heads, as shown in Figure 1, showed very small percentages of monoclinic phase (28 degrees 2 theta) with predominantly tetragonal phase (30 degrees 2theta), similar to what is observed in new components. Figure 1: XRD of typical retrieved ZR head surface.

All seven retrieved heads demonstrated no evidence suggesting that degradation of the Zirconia had occurred in-vivo.

This is the first report of surface-active phospholipid as the boundary lubricant in total hip arthroplasty. Aspirate and rinsings from the bearing surfaces of twenty four revisions have been analysed from three weeks to twenty six years postoperatively. All samples contained substantial amounts ranging from 14 to 4186 micrograms. Being a polar molecule, surface active phospholipid organises itself into layers similar to graphite (lamellated-solid lubrication).

These finding indicate that synoviocytes continue to produce the lubricant in significant quantities after arthroplasty surgery independent of the type of joint replacement and its fixation.

Surface-active phospholipid was found on all bearing surfaces analysed including polyethylene, stainless steel, chrome cobalt, Alumina, Zirconia and Titanium.