We have reviewed 97 consecutive primary hip replacements with a cemented femoral component and a porous-ingrowth acetabular component at a minimum five-year follow-up (average 6.5 years). The average Harris hip score was 93, and 85 hips had no pain or only slight pain. There had been no deterioration in the results since the two-year follow-up. The hybrid hip is successful for up to eight years and appears to be suitable for many patients. Long-term femoral fixation has been shown to improve with second-generation cementing techniques and in this series was excellent with third-generation techniques, in that only one stem was revised for loosening. No cementless acetabular component was revised for loosening

Nine uncemented hip prostheses of modular design were revised because of late infection (2 cases), femoral stem loosening or fracture (2), loosening of threaded cups (3) and protrusion of bipolar cups (2). At surgery we found tissue discoloration and macroscopic corrosion in four of the nine prostheses, located at the head-neck junction. Histological examination in most cases showed extensive necrosis associated with metal particles, indicating metal toxicity. Metallographic examination of the prosthetic heads revealed structural imperfections and inhomogeneity of the metal. We suggest that the crevice between the head and neck is a potential site of corrosion in modular designs

Between 1988 and 2006, 18 patients had a custom-made endoprosthetic replacement of the distal humerus for bone tumours at our institution. There were 11 primary malignant neoplasms, six secondary deposits, and one benign aggressive tumour. The mean follow-up was for 4.4 years (1 to 18.2). Complications occurred in nine patients and included aseptic loosening in three (16.6%), local recurrence in two (11%), infection in two (11%), neuropraxia of the radial nerve in one (5.5%) and a peri-prosthetic fracture in one (5.5%). Excision was inadequate in four patients (22%), all of which developed local recurrence and/or metastases. There were seven deaths from the primary disease after a mean of 2.3 years (1 to 5), one of whom had an above-elbow amputation for local recurrence seven months before death. The remaining six had satisfactory elbow function at their last follow-up. The 11 living patients were evaluated using the Musculoskeletal Tumour Society and Toronto Extremity Salvage scoring systems. The mean scores achieved were 76% (67% to 87%) and 73% (59% to 79%), respectively. Overall, 17 of 18 patients had significant improvement in the degree of their pain following operation. Custom-made endoprosthetic reconstruction of the elbow for bone tumours is a viable treatment in carefully selected patients. It maintains satisfactory function and provides good pain relief

Aims

The aim of this study was to compare the actual cost of a cemented and cementless total knee arthroplasty (TKA) procedure.

We have compared the survival of 67 revision arthroplasties of the knee undertaken for aseptic loosening with and without the retention of a secure, cemented femoral component. All the patients had undergone a single primary procedure at a mean of nine years previously. In group I (25 knees) the original femoral component was secure and was retained. There were no abrasions or osteolysis. The knees were stable, normally aligned, with minimal bone loss. In group II 42 knees did not fulfil these criteria and underwent revision of both components. The mean follow-up was four years. Re-revision for loosening was required in seven knees (28%) in group I and three (7%) in group II (p < 0.01). The remaining knees function well with Knee Society scores averaging 84/69 and no radiological evidence of osteolysis. When revising cemented implants, retention of a secure femoral component cannot be recommended even when conditions appear to be suitable

We reviewed our initial seven-year experience with a non-invasive extendible prosthesis in 34 children with primary bone tumours. The distal femur was replaced in 25 cases, total femur in five, proximal femur in one and proximal tibia in three. The mean follow-up was 44 months (15 to 86) and 27 patients (79%) remain alive. The prostheses were lengthened by an electromagnetic induction mechanism in an outpatient setting and a mean extension of 32 mm (4 to 80) was achieved without anaesthesia. There were lengthening complications in two children: failed lengthening in one and the formation of scar tissue in the other. Deep infection developed in six patients (18%) and local recurrence in three. A total of 11 patients required further surgery to the leg. Amputation was necessary in five patients (20%) and a two-stage revision in another. There were no cases of loosening, but two patients had implant breakage and required revision. The mean Musculoskeletal Tumor Society functional score was 85% (60% to 100%) at last known follow-up. These early results demonstrate that the non-invasive extendible prosthesis allows successful lengthening without surgical intervention, but the high incidence of infection is a cause for concern

We measured the levels of cobalt and chromium in the serum in three groups of patients after uncemented porous-coated arthroplasty. Group 1 consisted of 14 consecutive patients undergoing revision for aseptic loosening. Group 2 comprised 14 matched patients in whom the arthroplasty was stable and group 3 was 14 similarly matched patients with arthritis awaiting hip replacement. Specimens were analysed using atomic absorption spectrophotometry. Aseptic loosening of a component resulted in a significant elevation of serum cobalt (p < 0.05), but not of serum chromium. The relative risk of a component being loose, if the patient had a serum cobalt greater than 9.0 nmol/l, was 2.8

Aims

This study aimed to explore whether intraoperative nerve monitoring can identify risk factors and reduce the incidence of nerve injury in patients with high-riding developmental dysplasia.

Between April 1992 and July 2005, 310 posterior lip augmentation devices were used for the treatment of recurrent dislocation of the hip in 307 patients who had received primary total hip replacements (THRs) using Charnley/Charnley Elite components with a cemented acetabulum. The mean number of dislocations before stabilisation with the device was five (1 to 16) with a mean time to this intervention from the first dislocation of 3.8 years (0 days to 22.5 years). The mean age of the patients at this reconstruction was 75.4 years (39 to 96). A retrospective clinical and radiological review was carried out at a mean follow-up of six years and nine months (4.4 months to 13 years and 7 months). Of the 307 patients, 53 had died at the time of the latest review, with a functioning THR and with the posterior lip augmentation device in situ. There were four revisions (1.3%), one for pain, two for deep infection and one for loosening of the acetabular component. Radiolucent lines around the acetabular component increased in only six cases after insertion of the device which was successful in eliminating instability in 302 patients, with only five further dislocations (1.6%) occurring after its insertion

Fifty-seven Stanmore Total Hip replacements were implanted between 1974 and 1986 in patients under the age of 50 years. We have reviewed the results in terms of survivorship and function, and assessed the reasons for revision. Of the original 57, 22 (39%) have been revised at an average of 12 years from implantation, usually for aseptic loosening. Most of them had originally been implanted for osteoarthritis. Prostheses cemented with second-generation techniques have lasted significantly longer, and acetabular loosening emerged as a continuing problem. The overall survivorship was 90% at 10 years and 68% at 15 years. Cemented hip replacement appears to be a viable option in younger patients and the Stanmore implant is comparable with other cemented prostheses in this age group

Using a rat model, we created a bone-to-titanium interface and applied phagocytosable high-density polyethylene pArticles between the bone and implant, either initially or when the interface had matured. No fibrous membrane developed and no bone resorption was found. If sliding movements were initiated at the interface after two weeks, there was formation of a fibrous membrane. The additional application of pArticles did not change the thickness of the membrane, and there were only minor qualitative changes. Creation of a membrane by movement followed by cessation of movement and the application of pArticles caused the membrane to persist, whereas in a pArticle-free control group bone-to-metal contact was re-established. Our findings suggest that mechanical stimuli are of primary importance for prosthetic loosening, and that pArticles may modulate the later stages of the loosening process

Revision hip arthroplasty in patients with massive acetabular bone deficiency has generally given poor long-term results. We report the use of an 'anti-protrusio cage', secured to the ischium and ilium, which bridges areas of acetabular bone loss, provides support for the acetabular socket, and allows pelvic bone grafting in an environment protected from excessive stress. Forty-two failed hip arthroplasties with massive acetabular bone loss were revised with the Burch-Schneider anti-protrusio cage and evaluated after two to 11 years (mean five years). There was failure due to sepsis in five hips (12%) and aseptic loosening in five (12%); the remaining 32 hips (76%) showed no evidence of acetabular component failure or loosening

Over a 16-year period, 135 custom-made distal femoral prostheses, based on a fully constrained Stanmore-type knee replacement, were used in the treatment of primary malignant or aggressive benign tumours. Survivorship analysis showed a cumulative success rate of 72% at five years and 64% at seven years. Intact prostheses in 91% of the surviving patients gave good or excellent functional results. Deep infection was the major complication, occurring in 6.8% of cases; clinical aseptic loosening occurred in 6.0%. Revision surgery was carried out for loosening and infection, and the early results are encouraging. We conclude that prosthetic replacement of the distal femur can meet the objectives of limb salvage surgery

Aims

We previously reported the long-term results of the cementless Duraloc-Profile total hip arthroplasty (THA) system in a 12- to 15-year follow-up study. In this paper, we provide an update on the clinical and radiological results of a previously reported cohort of patients at 23 to 26 years´ follow-up.

We retrospectively reviewed 17 hip arthroplasties in 15 patients having haemodialysis for chronic renal failure. The duration of haemodialysis before the operation averaged 8.6 years and the average age of the patients was 61 years. All patients were followed for more than two years (mean 4.6 years). Six arthroplasties in four patients had failed due to loosening, and one of these patients died from undiagnosed infection of both hips at 7.6 years after the operation. General skeletal abnormalities caused by maintenance haemodialysis may explain the high incidence of loosening and it is important to be aware of the danger of postoperative infection. The risk-to-benefit ratio of hip arthroplasty is high in patients on haemodialysis

We performed a clinical and radiological study to determine the rate of failure of the Charnley Elite-Plus femoral component. Our aim was to confirm or refute the predictions of a previous roentgen stereophotogrammetric analysis study in which 20% of the Charnley Elite-Plus stems had shown rapid posterior head migration. It was predicted that this device would have a high early rate of failure. We examined 118 patients at a mean of nine years after hip replacement, including the 19 patients from the original roentgen stereophotogrammetric study. The number of revision procedures was recorded and clinical and radiological examinations were performed. The rate of survival of the femoral stems at ten years was 83% when revision alone was considered to be a failure. It decreased to 59% when a radiologically loose stem was also considered to be a failure. All the patients previously shown in the roentgen stereophotogrammetric study to have high posterior head migration went on to failure. There was a highly significant difference (p = 0.002) in posterior head migration measured at two years after operation between failed and non-failed femoral stems, but there was no significant difference in subsidence between these two groups. Our study has shown that the Charnley Elite-Plus femoral component has an unacceptably high rate of failure. It confirms that early evaluation of new components is important and that roentgen stereophotogrammetric is a good tool for this. Our findings have also shown that rapid posterior head migration is predictive of premature loosening and a better predictor than subsidence

Aims

The purpose of the present study was to compare patient-specific instrumentation (PSI) and conventional surgical instrumentation (CSI) for total knee arthroplasty (TKA) in terms of early implant migration, alignment, surgical resources, patient outcomes, and costs.

We studied the presence of sensory nerves by immunohistochemistry in the interface membranes of hip prostheses after aseptic loosening. Substance P (SP), neurokinin A (NKA) and calcitonin gene-related peptide (CGRP) were analysed as was protein gene product (PGP) 9.5, a general marker for nerve fibres. We identified nerve fibres in all samples but differences in their density were found. SP- and NKA-positive fibres were predominantly non-vascular, forming varicose nerve terminals. CGRP-immunoreactive nerve fibres with varicose terminals were seen mostly close to blood vessels, but also as free nerve endings. Sensory neuropeptides participate not only in nociception but also stimulate immune cells to release cytokines. The presence of sensory nerves in the interface membrane may reflect a pathophysiological response contributing to the aseptic loosening of hip prostheses

The role of inflammatory cells in aseptic loosening and failure of cemented joint replacements is unclear. Inflammatory cells from the revision joint capsule of four failed hip arthroplasties were examined to determine their nature and resorptive capacity. The capsules contained numerous macrophages and abundant foreign-body macrophage polykaryons, distinguished from osteoclasts by their antigenic phenotype and lack of response to calcitonin. When cultured on cortical bone slices in vitro, both macrophages and macrophage polykaryons produced small resorption pits and were associated with areas of superficial resorption of the bone surface. These results indicate that foreign-body induced macrophages and macrophage polykaryons are capable of a type of low-grade bone resorption which may be of pathogenic significance in the loosening of cemented joint prosthetic components