Impaction bone grafting for the reconstitution of bone stock in revision hip surgery has been used for nearly 30 years. Between 1995 and 2001 we used this technique in acetabular reconstruction, in combination with a cemented component, in 304 hips in 292 patients revised for aseptic loosening. The only additional supports used were stainless steel meshes placed against the medial wall or laterally around the acetabular rim to contain the graft. All Paprosky grades of defect were included. Clinical and radiographic outcomes were collected in surviving patients at a minimum of ten years after the index operation. Mean follow-up was 12.4 years (. sd. 1.5) (10.0 to 16.0). Kaplan–Meier survival with revision for aseptic loosening as the endpoint was 85.9% (95% CI 81.0 to 90.8) at 13.5 years. Clinical scores for pain relief remained satisfactory, and there was no difference in clinical scores between cups that appeared stable and those that appeared radiologically loose. . Cite this article: Bone Joint J 2014;96-B:188–94

1. Electron-probe microanalysis shows that corrosion of an 18 per cent chromium-8 per cent nickel-3 per cent molybdenum stainless steel implant and of some pure metal implants may affect not only the surrounding tissues but also the individual cells. 2. Metallic contamination from surgical tools is confirmed. 3. Electron-probe microanalysis is shown to be a useful tool for studying individual biological cells. 4. The principles of electron-probe microanalysis are described

Aims

This study aimed to assess the carbon footprint associated with total hip arthroplasty (THA) in a UK hospital setting, considering various components within the operating theatre. The primary objective was to identify actionable areas for reducing carbon emissions and promoting sustainable orthopaedic practices.

The tissue surrounding carbon fibre reinforced epoxy resin plates applied to forearm and tibial fractures was biopsied in 32 patients at the time the plates were removed. The reaction was minimal and was compared with that in a control group of 16 similar patients in whom stainless steel plates were used. No significant histological differences were found. A series of experiments on rats, in which the histology was studied from 2 to 78 weeks, also showed that there was very little reaction to carbon fibre reinforced plastic

We compared the mechanical properties of carbon fibre composite bone plates with those of stainless steel and titanium. The composite plates have less stiffness with good fatigue properties. Tissue culture and small animal implantation confirmed the biocompatibility of the material. We also present a preliminary report on the use of the carbon fibre composite plates in 40 forearm fractures. All fractures united, 67% of them showing radiological remodelling within six months. There were no refractures or mechanical failures, but five fractures showed an unexpected reaction; this is discussed

1. The factors producing electrolytic corrosion of stainless steels are reviewed, and it is shown how several factors operating together can accentuate corrosion in certain positions in the plated fracture. 2. These factors can be minimised by good metallurgy and good engineering on the part of the manufacturers. 3. When and if materials become metallurgically satisfactory, or a truly inert substitute for metal is discovered, it will be possible to assess the true contribution of infection, faulty operative technique and mechanical factors to the failures of internal fixation. Such a critical assessment of these probably more important factors is at present bedevilled by uncertainty as to the purely physical condition of the materials as supplied to the surgeon

Interfacial membranes collected at revision from 11 failed uncemented Ti-alloy total hip replacements were examined. Particles in the membranes were characterised by electron microscopy, microchemical spectroscopy and particle size analysis. Most were polyethylene and had a mean size of 0.53 micron +/- 0.3. They were similar to the particles seen in the base resin used in the manufacture of the acetabular implants. Relatively few titanium particles were seen. Fragments of bone, stainless steel and silicate were found in small amounts. Most of the polyethylene particles were too small to be seen by light microscopy. Electron microscopy and spectroscopic techniques are required to provide an accurate description of this debris

A new cosmetic weight-relieving brace which utilises stainless steel and light alloy in its structure is described. A clinical assessment of thirty-six patients (four bilateral cases) has shown the Salford Cosmetic brace to be suitable for over 80 per cent of patients attending for assessment. Five patients rejected the brace, and the reasons are discussed. Contra-indications which emerged during the assessment included limb shortening of more than 5 centimetres; fixed equinus of more than 10 degrees; and fixed deformity of the knee of more than 10 degrees. The safety and durability of the brace, first demonstrated in laboratory tests, are confirmed. Further possible development is outlined

The purpose of this study was to determine the biological effects of the elastic modulus of the femoral stem in canine hip arthroplasty. Cementless total hip arthroplasty was performed in 12 dogs, six had a low elastic modulus polyacetal resin stem and six had a high modulus stainless steel stem. The components were otherwise similar. At six and 12 months after operation, radiographic and histomorphometric analysis showed that those with steel implants had more cortical porosity than did the other group (p less than 0.01). We suggest that the elastic modulus of the implant is an important factor in controlling cortical bone resorption. A low modulus femoral prosthesis can significantly decrease bone resorption which might otherwise eventually lead to implant failure

1. Stainless steel mould arthroplasty of the knee is described and a ten-year follow-up study of sixty-two operations is reported. Fifty-four were for rheumatoid arthritis and eight for osteoarthritis. 2. Forty-nine of the sixty-two joints retained mobility, six had become ankylosed and five were later arthrodesed ; two limbs were amputated. The forty-nine mobile knees included twenty-seven which were painless at all times, and fourteen in which only an occasional twinge was felt. 3. The range of movement was increased in twenty-two joints as compared with the state before operation, diminished in twelve and unaltered in five. In ten knees measurements before operation were not available. 4. Flexion deformity, swelling, stability and function were improved in a significant number of joints. 5. Patients suffering from active rheumatoid arthritis often found that the joint operated upon no longer took part in generalised flares of the disease

1. Multiple barbed sutures made from nylon are described and the theoretical advantages with the use of the nylon are outlined. 2. Methods of joining tendon stumps using the multiple barbed sutures are illustrated and in vitro tests show that the anchorage of this suture in cadaveric and canine flexor tendons is of the same order. 3. Preliminary in vivo tests where the flexor digitorum profundus tendon of dogs have been repaired with multiple barbed sutures show that it maintains apposition of the tendon stump as effectively as the Bunnell "buried core" technique using G 40 stainless steel wire. 4. The multiple barbed suture is an experimental suture for certain compact tendons capable of giving a neat and relatively atraumatic junction. It requires further study and development. It does not appear to make tendon repair technically easier, nor does it alter the indications for operation or management

Twenty-two high-density polyethylene sockets from Charnley low-friction arthroplasties have been studied. Acrylic casts and shadowgraph techniques were used to measure both the real and radiographic rates of wear; these rates showed a significant correlation. In the sagittal plane, nine of the sockets had worn lateral to a line drawn vertically from the centre of curvature of the socket, 12 had worn medial to that line and only one was worn exactly in the line. In the coronal plane, nine sockets had worn in front of a similar vertical line, two behind that line and 11 had worn exactly in the line. Evidence of impingement of the neck of the stem onto the rim of the socket was found in 14 patients; this is considered to be one of the causes of socket loosening. The obvious solution is to reduce the diameter of the neck of the stem from 12.5 mm to 10 mm; provided that it is made of cold-formed, high nitrogen-content stainless steel, this narrower neck is strong enough not to fracture

Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements

Wear products of metal implants are known to induce biological events which may have profound consequences for the microcirculation of skeletal muscle. Using the skinfold chamber model and intravital microscopy we assessed microcirculatory parameters in skeletal muscle after confrontation with titanium and stainless-steel wear debris, comparing the results with those of bulk materials. Implantation of stainless-steel bulk and debris led to a distinct activation of leukocytes combined with a disruption of the microvascular endothelial integrity and massive leukocyte extravasation. While animals with bulk stainless steel showed a tendency to recuperation, stainless-steel wear debris induced such severe inflammation and massive oedema that the microcirculation broke down within 24 hours after implantation. Titanium bulk caused only a transient increase in leukocyte-endothelial cell interaction within the first 120 minutes and no significant change in macromolecular leakage, leukocyte extravasation or venular diameter. Titanium wear debris produced a markedly lower inflammatory reaction than stainless-steel bulk, indicating that a general benefit of bulk versus debris could not be claimed. Depending on its constituents, wear debris is capable of eliciting acute inflammation which may result in endothelial damage and subsequent failure of microperfusion. Our results indicate that not only the bulk properties of orthopaedic implants but also the microcirculatory implications of inevitable wear debris play a pivotal role in determining the biocompatibility of an implant

Aims

Bacteriophages infect, replicate inside bacteria, and are released from the host through lysis. Here, we evaluate the effects of repetitive doses of the Staphylococcus aureus phage 191219 and gentamicin against haematogenous and early-stage biofilm implant-related infections in Galleria mellonella.

Some of the component metals of the alloys used for total joint prostheses are toxic and dissolve in the body fluids. It is important to establish how toxic these metals are and to assess the risk of localised tissue necrosis around the prostheses. This has been investigated by incubating primary monolayer cultures of human synovial fibroblasts with various preparations of metals for periods up to 18 days. Morphological changes were evident after exposure to cobalt chloride at a concentration of 50 nanomoles per millilitre and to nickel chloride at 200 nanomoles per millilitre. Chromic chloride, ammonium molybdate and ferric chloride produced no changes up to 500 nanomoles per millilitre. Cultures exposed to particulate pure metals were poisoned by cobalt and vanadium but were not affected under the same conditions by nickel, chromium, molybdenum, titanium or aluminium. Particulate cobalt and vanadium were probably toxic due to their relatively high solubility (four and one micromoles per millilitre respectively after seven days incubation). Particulate nickel also dissolved (three nanomoles per millilitre after seven days) but not in sufficient quantities to be toxic. It appears, therefore, that potentially the most harmful components are cobalt from cobalt-chromium alloy, nickel from stainless steel, and vanadium from titanium alloy. As far as can be estimated, the only combination of materials which is likely to give rise to toxic levels of metal under clinical conditions, is cobalt-chromium alloy articulating against itself to produce relatively high levels of cobalt

1. Currently available total replacement hip and knee prostheses were tested in a machine enabling flexion-extension movements to be applied whilst the prostheses were surrounded with Ringer's solution or other liquid and loaded within the physiological range. 2. Prostheses of which both components were made in cobalt-chromium-molybdenum alloy produced visible quantities of alloy particles, whose sizes ranged down to about 0·1 microns, and cobalt and molybdenum ions in solution. 3. No metallic or plastic particles were detected during tests on a hip prosthesis made of stainless steel and high density polyethylene. 4. The frictional moments in cobalt-chromium-molybdenum hip prostheses were higher than in stainless steel-polyethylene hip prostheses, by a factor of at least 2 to 1. 5. It is accepted that the conditions of these tests were probably more severe than in life, but the difference is held to be one of degree and not one of kind. 6. The particulate alloy debris, when injected in massive doses into the muscles of rats, gave an incidence of malignant tumours which was comparable to that already established for pure cobalt powder, whereas particles of several other metals, tested in the same way, gave no tumours. 7. It is argued that the particles which are known to be produced in at least some patients using cobalt-chromium-molybdenum total replacement joint prostheses constitute a risk of tumour formation which is certainly small, possibly negligible, but not accurately calculable at present. 8. The results of these tests, particularly the differences in frictional moment and in the production of particulate debris, suggest a preference for high density polyethylene as one component of a total joint replacement prosthesis

Aims

Periprosthetic hip fractures (PPFs) after total hip arthroplasty are difficult to treat. Therefore, it is important to identify modifiable risk factors such as stem selection to reduce the occurrence of PPFs. This study aimed to clarify differences in fracture torque, surface strain, and fracture type analysis between three different types of cemented stems.

Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF.

Cite this article: Bone Joint J 2024;106-B(1):11–15.

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.