The recent resurgence in the use of metal-on-metal bearings has led to fresh concerns over metal wear and elevated systemic levels of metal ions.

In order to establish if bearing diameter influences the release of metal ions, we compared the whole blood levels of cobalt and chromium (at one year) and the urinary cobalt and chromium output (at one to three and four to six years) following either a 50 mm or 54 mm Birmingham hip resurfacing or a 28 mm Metasul total hip replacement. The whole blood concentrations and daily output of cobalt and chromium in these time periods for both bearings were in the same range and without significant difference.

We evaluated the results of rotational acetabular osteotomy in 44 hips (42 patients) with advanced osteoarthritis secondary to developmental dysplasia. The mean age of the patients at surgery was 43.4 years (30 to 59) and the mean follow-up was 12.1 years (8 to 19).

The mean Merle d’Aubigné clinical score improved from 10.8 points (8 to 15) pre-operatively to 13.5 points (6 to 18) at follow-up. Radiologically, this procedure produced adequate improvement regarding cover of the femoral head. At follow-up, the osteoarthritic stage assessed using the Japanese Orthopaedic Association grading, was improved in 11 hips (25%), unchanged in 22 (50%) and had progressed in 11 (25%). The mean pre-operative roundness index of the femoral head was significantly different in the 33 hips which had improved or maintained their osteoarthritic stage compared with the 11 which had progressed (53.7% vs 63.7%; p < 0.001).

Osteoarthritis with a round femoral head is considered to be an indication for rotational acetabular osteotomy, even in advanced stages of the disease.

We evaluated the cost and consequences of proximal femoral fractures requiring further surgery because of complications. The data were collected prospectively in a standard manner from all patients with a proximal femoral fracture presenting to the trauma unit at the John Radcliffe Hospital over a five-year period. The total cost of treatment for each patient was calculated by separating it into its various components. The risk factors for the complications that arose, the location of their discharge and the mortality rates for these patients were compared to those of a matched control group. There were 2360 proximal femoral fractures in 2257 patients, of which 144 (6.1%) required further surgery. The mean cost of treatment in patients with complications was £18 709 (£2606.30 to £60.827.10), compared with £8610 (£918.54 to £45 601.30) for uncomplicated cases (p < 0.01), with a mean length of stay of 62.8 (44.5 to 79.3) and 32.7 (23.8 to 35.0) days, respectively. The probability of mortality after one month in these cases was significantly higher than in the control group, with a mean survival of 209 days, compared with 496 days for the controls. Patients with complications were statistically less likely to return to their own home (p < 0.01).

Greater awareness and understanding are required to minimise the complications of proximal femoral fractures and consequently their cost.

Peri-articular soft-tissue masses or ‘pseudotumours’ can occur after large-diameter metal-on-metal (MoM) resurfacing of the hip and conventional total hip replacement (THR). Our aim was to assess the incidence of pseudotumour formation and to identify risk factors for their formation in a prospective cohort study.

A total of 119 patients who underwent 120 MoM THRs with large-diameter femoral heads between January 2005 and November 2007 were included in the study. Outcome scores, serum metal ion levels, radiographs and CT scans were obtained. Patients with symptoms or an identified pseudotumour were offered MRI and an ultrasound-guided biopsy.

There were 108 patients (109 hips) eligible for evaluation by CT scan at a mean follow-up of 3.6 years (2.5 to 4.5); 42 patients (39%) were diagnosed with a pseudotumour. The hips of 13 patients (12%) were revised to a polyethylene acetabular component with small-diameter metal head. Patients with elevated serum metal ion levels had a four times increased risk of developing a pseudotumour.

This study shows a substantially higher incidence of pseudotumour formation and subsequent revisions in patients with MoM THRs than previously reported. Because most revision cases were identified only after an intensive screening protocol, we recommend close monitoring of patients with MoM THR.

The hip joint is commonly involved in multiple epiphyseal dysplasia and patients may require total hip replacement before the age of 30 years.

We retrospectively reviewed nine patients (16 hips) from four families. The diagnosis of multiple epiphyseal dysplasia was based on a family history, genetic counselling, clinical features and radiological findings. The mean age at surgery was 32 years (17 to 63), with a mean follow-up of 15.9 years (5.5 to 24).

Of the 16 hips, ten required revision at a mean of 12.5 years (5 to 15) consisting of complete revision of the acetabular component in three hips and isolated exchange of the liner in seven. No femoral component has loosened or required revision during the period of follow-up.

With revision for any reason, the 15-year survival was only 11.4% (95% confidence interval 1.4 to 21.4). However, when considering revision of the acetabular shell in isolation the survival at ten years was 93.7% (95% confidence interval 87.7 to 99.7), reducing to 76.7% (95% confidence interval 87.7 to 98.7) at 15 and 20 years, respectively.

In this retrospective study, using the prospectively collected database of the AO-Documentation Centre, we analysed the outcome of 57 malunited fractures of the ankle treated by reconstructive osteotomy. In all cases the position of the malunited fibula had been corrected, in several cases it was combined with other osteotomies and the fixation of any non-united fragments. Patients were seen on a regular basis, with a minimum follow-up of ten years. The aim of the study was to establish whether reconstruction improves ankle function and prevents the progression of arthritic changes.

Good or excellent results were obtained in 85% (41) of patients indicating that reconstructive surgery is effective in most and that the beneficial effects can last for up to 27 years after the procedure. Minor post-traumatic arthritis is not a contraindication but rather an indication for reconstructive surgery. We also found that prolonged time to reconstruction is associated negatively with outcome.

Autologous chondrocyte implantation is an option in the treatment of full-thickness chondral or osteochondral injuries which are symptomatic. The goal of surgery and rehabilitation is the replacement of damaged cartilage with hyaline or hyaline-like cartilage, producing improved levels of function and preventing early osteoarthritis. The intermediate results have been promising in terms of functional and clinical improvement.

Our aim was to explore the hypothesis that the histological quality of the repair tissue formed after autologous chondrocyte implantation improved with increasing time after implantation.

In all, 248 patients who had undergone autologous chondrocyte implantation had biopsies taken of the repair tissue which then underwent histological grading. Statistical analysis suggested that with doubling of the time after implantation the likelihood of a favourable histological outcome was increased by more than fourfold (p < 0.001).

Idiopathic calcium pyrophosphate deposition disease (pseudogout) has a variable presentation. Many joints are usually affected; single joint disease is uncommon. We present a case report of primary monoarticular pseudogout affecting the hip. The diagnosis was made on the appearance and analysis of specimens obtained at arthroscopy. Monoarticular pseudogout is rare, but should be considered in the differential diagnosis of any presentation of joint pain.

A prospective study of serum and urinary ion levels was undertaken in a triathlete who had undergone a metal-on-metal resurfacing arthroplasty of the hip four years previously. The one month study period included the final two weeks of training, the day of the triathlon, and the two weeks immediately post-race. Serum cobalt and chromium levels did not vary significantly throughout this period, including levels recorded on the day after the 11-hour triathlon. Urinary excretion of chromium increased immediately after the race and had returned to pre-race levels six days later. The clinical implications are discussed.

We reviewed 116 patients who underwent 118 arthroscopic ankle arthrodeses. The mean age at operation was 57 years, 2 months (20 to 86 years). The indication for operation was post-traumatic osteoarthritis in 67, primary osteoarthritis in 36, inflammatory arthropathy in 13 and avascular necrosis in two. The mean follow-up was 65 months (18 to 144). Nine patients (10 ankles) died before final review and three were lost to follow-up, leaving 104 patients (105 ankles) who were assessed by a standard telephone interview. The pre-operative talocrural deformity was between 22° valgus and 28° varus, 94 cases were within 10° varus/valgus. The mean time to union was 12 weeks (6 to 20). Nonunion occurred in nine cases (7.6%). Other complications included 22 cases requiring removal of a screw for prominence, three superficial infections, two deep vein thromboses/pulmonary emboli, one revision of fixation, one stress fracture and one deep infection. Six patients had a subtalar fusion at a mean of 48 months after ankle fusion. There were 48 patients with excellent, 35 with good, 10 with fair and 11 with poor clinical results.

Using the General Practice Research Database, we examined the temporal changes in the rates of primary total hip (THR) and total knee (TKR) replacement, the age at operation and the female-to-male ratio between 1991 and 2006 in the United Kingdom.

We identified 27 113 patients with THR and 23 843 with TKR. The rate of performance of THR and TKR had increased significantly (p < 0.0001 for both) during the 16-year period and was greater for TKR, especially in the last five years. The mean age at operation was greater for women than for men and had remained stable throughout the period of study. The female-to-male ratio was higher for THR and TKR and had remained stable.

The data support the notion that the rate of joint replacement is increasing in the United Kingdom with the rate of TKR rising at the highest rate. The perception that the mean age for TKR has decreased over time is not supported.

We describe 119 meniscal allograft transplantations performed concurrently with articular cartilage repair in 115 patients with severe articular cartilage damage. In all, 53 (46.1%) of the patients were over the age of 50 at the time of surgery. The mean follow-up was for 5.8 years (2 months to 12.3 years), with 25 procedures (20.1%) failing at a mean of 4.6 years (2 months to 10.4 years). Of these, 18 progressed to knee replacement at a mean of 5.1 years (1.3 to 10.4). The Kaplan-Meier estimated mean survival time for the whole series was 9.9 years (sd 0.4). Cox’s proportional hazards model was used to assess the effect of covariates on survival, with age at the time of surgery (p = 0.026) and number of previous operations (p = 0.006) found to be significant.

The survival of the transplant was not affected by gender, the severity of cartilage damage, axial alignment, the degree of narrowing of the joint space or medial versus lateral allograft transplantation. Patients experienced significant improvements at all periods of follow-up in subjective outcome measures of pain, activity and function (all p-values < 0.05), with the exception of the seven-year Tegner index score (p = 0.076).

We describe the treatment by subperiosteal resection of an aneurysmal bone cyst in the distal fibula in eight patients and highlight the role of the periosteum in the regeneration of bone defects. The mean age of the patients was 13.5 years (12 to 17). Seven had an open growth plate. The mean size of the resected specimen was 5.12 cm (3.5 to 8.0). None of the patients received instillation of bone marrow, autogenous bone graft, allograft or any synthetic bone substitutes.

All had complete regeneration of the bone defect within three to nine months, with no joint instability or recurrence.

The mean length of follow-up was 11.5 years (2 to 18). At the final follow-up there was no difference in the range of movement, alignment or stability of the ankle when compared with the opposite side. The periosteum played a major role in the complete filling of the bone defects and avoided the morbidity of other techniques.

The design of the Charnley total hip replacement follows the principle of low frictional torque. It is based on the largest possible difference between the radius of the femoral head and that of the outer aspect of the acetabular component. The aim is to protect the bone-cement interface by movement taking place at the smaller radius, the articulation. This is achieved in clinical practice by a 22.225 mm diameter head articulating with a 40 mm or 43 mm diameter acetabular component of ultra-high molecular weight polyethylene.

We compared the incidence of aseptic loosening of acetabular components with an outer diameter of 40 mm and 43 mm at comparable depths of penetration with a mean follow-up of 17 years (1 to 40).

In cases with no measurable wear none of the acetabular components were loose. With increasing acetabular penetration there was an increased incidence of aseptic loosening which reflected the difference in the external radii, with 1.5% at 1 mm, 8.8% at 2 mm, 9.7% at 3 mm and 9.6% at 4 mm of penetration in favour of the larger 43 mm acetabular component.

Our findings support the Charnley principle of low frictional torque. The level of the benefit is in keeping with the predicted values.

The Oxford Unicompartmental Knee replacement (UKR) was introduced as a design to reduce polyethylene wear. There has been one previous retrieval study involving this implant, which reported very low rates of wear in some specimens but abnormal patterns of wear in others. There has been no further investigation of these abnormal patterns. The bearings were retrieved from 47 patients who had received a medial Oxford UKR for anteromedial osteoarthritis of the knee. None had been studied previously. The mean time to revision was 8.4 years (sd 4.1), with 20 having been implanted for over ten years. The macroscopic pattern of polyethylene wear and the linear penetration were recorded for each bearing. The mean rate of linear penetration was 0.07 mm/year. The patterns of wear fell into three categories, each with a different rate of linear penetration; 1) no abnormal macroscopic wear and a normal articular surface, n = 16 (linear penetration rate = 0.01 mm/year); 2) abnormal macroscopic wear and normal articular surfaces with extra-articular impingement, n = 16 (linear penetration rate = 0.05 mm/year); 3) abnormal macroscopic wear and abnormal articular surfaces with intra-articular impingement +/− signs of non-congruous articulation, n = 15 (linear penetration rate = 0.12 mm/year). The differences in linear penetration rate were statistically significant (p < 0.001).

These results show that very low rates of polyethylene wear are possible if the device functions normally. However, if the bearing displays suboptimal function (extra-articular, intra-articular impingement or incongruous articulation) the rates of wear increase significantly.

We have reviewed a group of patients with iliopsoas impingement after total hip replacement with radiological evidence of a well-fixed malpositioned or oversized acetabular component. A consecutive series of 29 patients (30 hips) was assessed. All had undergone a trial of conservative management with no improvement in their symptoms. Eight patients (eight hips) preferred continued conservative management (group 1), and 22 hips had either an iliopsoas tenotomy (group 2) or revision of the acetabular component and debridement of the tendon (group 3), based on clinical and radiological findings. Patients were followed clinically for at least two years, and 19 of the 22 patients (86.4%) who had surgery were contacted by phone at a mean of 7.8 years (5 to 9) post-operatively. Conservative management failed in all eight hips. At the final follow-up, operative treatment resulted in relief of pain in 18 of 22 hips (81.8%), with one hip in group 2 and three in group 3 with continuing symptoms. The Harris Hip Score was significantly better in the combined groups 2 and 3 than in group 1. There was a significant rate of complications in group 3. This group initially had better functional scores, but at final follow-up these were no different from those in group 2.

Tenotomy of the iliopsoas and revision of the acetabular component are both successful surgical options. Iliopsoas tenotomy provided the same functional results as revision of the acetabular component and avoided the risks of the latter procedure.

We performed a systematic review of the optimal management of septic arthritis in children as recommended in the current English literature using MEDLINE, EMBASE, CINAHL, the Cochrane Library and reference lists of retrieved articles without date restrictions up to 31 January 2009. From 2236 citations, 227 relevant full-text articles were screened in detail; 154 papers fulfilled the inclusion criteria, from which conclusions were drawn on the management of infected joints in children.

Our review showed that no single investigation, including joint aspiration, is sufficiently reliable to diagnose conclusively joint infection. The roles of aspiration, arthrotomy and arthroscopy in treatment are not clear cut, and the ideal duration of antibiotic therapy is not yet fully defined. These issues are discussed. Further large-scale, multi-centre studies are needed to delineate the optimal management of paediatric septic arthritis.

Neurological conditions affecting the hip pose a considerable challenge in replacement surgery since poor and imbalanced muscle tone predisposes to dislocation and loosening. Consequently, total hip replacement (THR) is rarely performed in such patients. In a systematic review of the literature concerning THR in neurological conditions, we found only 13 studies which described the outcome. We have reviewed the evidence and discussed the technical challenges of this procedure in patients with cerebral palsy, Parkinson’s disease, poliomyelitis and following a cerebrovascular accident, spinal injury or development of a Charcot joint. Contrary to traditional perceptions, THR can give a good outcome in these often severly disabled patients.

Metal ions generated from joint replacements are a cause for concern. There is no consensus on the best surrogate measure of metal ion exposure. This study investigates whether serum and whole blood concentrations can be used interchangeably to report results of cobalt and chromium ion concentrations.

Concentrations of serum and whole blood were analysed in 262 concurrent specimens using high resolution inductively-coupled plasma mass-spectrometry. The agreement was assessed with normalised scatterplots, mean difference and the Bland and Altman limits of agreement.

The wide variability seen in the normalised scatterplots, in the Bland and Altman plots and the statistically significant mean differences between serum and whole blood concentrations suggest that they cannot be used interchangeably. A bias was demonstrated for both ions in the Bland-Altman plots. Regression analysis provided a possible conversion factor of 0.71 for cobalt and 0.48 for chromium. However, even when the correction factors were applied, the limits of agreement were greater than ±67% for cobalt and greater than ±85% for chromium, suggesting that serum and whole blood cannot be used interconvertibly. This suggests that serum metal concentrations are not useful as a surrogate measure of systemic metal ion exposure.