We report the follow-up at 12 years of the use of the Elite Plus total hip replacement (THR). We have previously reported the results at a mean of 6.4 years. Of the 217 patients (234 THRs), 83 had died and nine had been lost to follow-up. The patients were reviewed radiologically and clinically using the Oxford hip score.

Of the 234 THRs, 19 (8.1%) had required a revision by the final follow-up in all but one for aseptic loosening. Survivorship analysis for revision showed a survival of 93.9% (95% confidence interval (CI) 89.2 to 96.5) at ten years, and of 88.0% (95% CI 81.8 to 92.3) at 12 years. At the final follow-up survival analysis showed that 37% (95% CI 37.3 to 44.7) of the prostheses had either failed radiologically or had been revised. Patients with a radiologically loose femoral component had a significantly poorer Oxford hip score than those with a well-fixed component (p = 0.03). Radiological loosening at 6.4 years was predictive of failure at 12 years.

Medium-term radiographs and clinical scores should be included in the surveillance of THR to give an early indication of the performance of specific implants.

We carried out metal artefact-reduction MRI, three-dimensional CT measurement of the position of the component and inductively-coupled plasma mass spectrometry analysis of cobalt and chromium levels in whole blood on 26 patients with unexplained pain following metal-on-metal resurfacing arthroplasty.

MRI showed periprosthetic lesions around 16 hips, with 14 collections of fluid and two soft-tissue masses. The lesions were seen in both men and women and in symptomatic and asymptomatic hips. Using three-dimensional CT, the median inclination of the acetabular component was found to be 55° and its positioning was outside the Lewinnek safe zone in 13 of 16 cases. Using inductively-coupled plasma mass spectrometry, the levels of blood metal ions tended to be higher in painful compared with well-functioning metal-on-metal hips.

These three clinically useful investigations can help to determine the cause of failure of the implant, predict the need for future revision and aid the choice of revision prostheses.

We undertook a randomised controlled trial to compare the outcomes of skin adhesive and staples for skin closure in total hip replacement. The primary outcome was the cosmetic appearance of the scar at three months using a surgeon-rated visual analogue scale. In all, 90 patients were randomised to skin closure using either skin adhesive (n = 45) or staples (n = 45). Data on demographics, surgical details, infection and oozing were collected during the in-patient stay. Further data on complications, patient satisfaction and evaluation of cosmesis were collected at three-month follow-up, and a photograph of the scar was taken. An orthopaedic and a plastic surgeon independently evaluated the cosmetic appearance of the scars from the photographs. No significant difference was found between groups in the cosmetic appearance of scars at three months (p = 0.172), the occurrence of complications (p = 0.3), or patient satisfaction (p = 0.42). Staples were quicker and easier to use than skin adhesive and also less expensive. Skin adhesive and surgical staples are both effective skin closure methods in total hip replacement.

Between 1999 and 2005, 10 264 patients who had undergone total hip replacement (THR) for subcapital fracture of the hip were compared with 76 520 in whom THR had been performed for other reasons. All the cases were identified through the Swedish Hip Arthroplasty Register. The THRs performed as primary treatment for fracture were also compared with those done after failure of internal fixation.

After seven years the rate of revision was higher in THR after fracture (4.4% vs 2.9%). Dislocation and periprosthetic fracture were the most common causes of revision. The risk was higher in men than in women. The type of femoral component and the surgical approach influenced the risk. After correction for gender, type of component and the surgical approach the revision rates were similar in the primary and secondary fracture THR groups.

Total hip replacement is therefore a safe method for both the primary and secondary management of fracture of the hip.

The removal of well-fixed bone cement from the femoral canal during revision of a total hip replacement (THR) can be difficult and risks the loss of excessive bone stock and perforation or fracture of the femoral shaft. Retaining the cement mantle is attractive, yet the technique of cement-in-cement revision is not widely practised. We have used this procedure at our hospital since 1989. The stems were removed to gain a better exposure for acetabular revision, to alter version or leg length, or for component incompatibility.

We studied 136 hips in 134 patients and followed them up for a mean of eight years (5 to 15). A further revision was required in 35 hips (25.7%), for acetabular loosening in 26 (19.1%), sepsis in four, instability in three, femoral fracture in one and stem fracture in one. No femoral stem needed to be re-revised for aseptic loosening.

A cement-in-cement revision of the femoral stem is a reliable technique in the medium term. It also reduces the risk of perforation or fracture of the femoral shaft.

Muscle atrophy has been demonstrated in patients suffering from osteoarthritis of the hip, but little is known about muscular recovery after total hip replacement (THR). A total of 20 patients with unilateral osteoarthritis of the hip were assessed before, six months and two years after THR. The cross-sectional area and radiological density of the muscles of the hip, thigh, calf and back were measured using CT. We hypothesised that the muscles would not recover fully after operation.

After two years comparison of the limb with the THR with the healthy limb showed that there was such a reduction in the cross-sectional area in iliopsoas (7.0%; p = 0.006) and the hip adductors (8.4%, p = 0.003) and in the radiological density in gluteus maximus (10.1 Hounsfield units; p < 0.001), gluteus medius/minimus (5.6 Hounsfield units; p = 0.011), iliopsoas (3.9 Hounsfield units; p < 0.001) and the adductors (2.4 Hounsfield units; p = 0.022).

Thus, there was persistent muscle atrophy in muscles acting about the hip two years after THR. We suggest that an earlier operation or a more intensive rehabilitation may reverse these changes.

Femoroacetabular impingement is a cause of hip pain in adults and is potentially a precursor of osteoarthritis. Our aim in this study was to determine the prevalence of bilateral deformity in patients with symptomatic cam-type femoroacetabular impingement as well as the presence of associated acetabular abnormalities and hip pain. We included all patients aged 55 years or less seen by the senior author for hip pain, with at least one anteroposterior and lateral pelvic radiograph available. All patients with dysplasia and/or arthritis were excluded. A total of 113 patients with a symptomatic cam-impingement deformity of at least one hip was evaluated. There were 82 men and 31 women with a mean age of 37.9 years (16 to 55).

Bilateral cam-type deformity was present in 88 patients (77.8%) while only 23 of those (26.1%) had bilateral hip pain. Painful hips had a statistically significant higher mean alpha angle than asymptomatic hips (69.9° vs 63.1°, p < 0.001). Hips with an alpha angle of more than 60° had an odds ratio of being painful of 2.59 (95% confidence interval 1.32 to 5.08, p = 0.006) compared with those with an alpha angle of less than 60°. Of the 201 hips with a cam-impingement deformity 42% (84) also had a pincer deformity.

Most patients with cam-type femoroacetabular impingement had bilateral deformities and there was an associated acetabular deformity in 84 of 201 patients (42%). This information is important in order to define the natural history of these deformities, and to determine treatment.

We identified 1305 femoral impaction bone grafting revisions using the Exeter stem performed between 1989 and 2002 in 30 hospitals throughout Sweden. There were 1188 patients with a mean age of 71 years (29 to 94) followed up for between five and 18 years.

The participating departments reported 70 further revisions in total, of which 57 could also be identified on the Swedish National Arthroplasty Registry.

Kaplan-Meier survivorship for all causes of failure was 94.0% (95% confidence interval (CI) 92 to 96) for women and 94.7% (95% CI, 92 to 96) for men at 15 years. Survivorship at 15 years for aseptic loosening was 99.1% (95% CI 98.4 to 99.5), for infection 98.6% (95% CI 97.6 to 99.2), for subsidence 99.0% (95% CI 98.2 to 99.4) and for fracture 98.7% (95% CI 97.9 to 99.2)

Statistically significant predictors of failure were the year in which revision was conducted (p < 0.001). The number of previous revisions was slightly above the level of signifance (p = 0.056). Age, gender, the length of the stem and previous septic loosening were not predictors of failure (p = 0.213, p = 0.399, p = 0.337, p = 0.687, respectively). The difference in survivorship between high- and low-volume departments was only 3% at ten years.

We conclude that impaction bone grafting with the Exeter stem has an excellent long-term survivorship following revision arthroplasty. The technique of impaction grafting appears to be reliable, can be learned rapidly and produces a predictably low incidence of aseptic loosening.

Of the 11 054 Charnley low-frictional torque arthroplasties carried out at our hospital between 1962 and 1977, 110 (94 patients) had a minimum follow-up of 30 years with a mean of 32.3 years (30.0 to 40.5). The mean age of the patients at operation was 43.3 years (17.0 to 65.0) and 75.7 years (51.0 to 97.0) at follow-up. Overall, 90% of hips (99) were free from pain and activity was reported as normal in 58% of the patients.

A total of 13 hips (11.8%) were revised at a mean follow-up of 32.3 years (30.0 to 39.5), with wear and loosening of the acetabular component as the main indications.

The clinical results did not reflect the mechanical state of the implant. Follow-up with sequential radiographs of good quality is essential. Revision for radiological changes alone must be accepted if gross loss of bone stock is to be avoided.

Improvements in the design, materials and operative technique, based on the long-term outcome, are highlighted.

Digital templating in hip replacement is commonly performed with radiological markers to determine the magnification. The latter can also be determined by measuring the distance from the x-ray focal spot to the object and the distance from the x-ray focal spot to the radiological cassette or image receptor. We used post-operative radiographs of total hip replacements and hemiarthroplasties from 22 patients to calculate the magnification using both methods. The accuracy of each method was ascertained by measuring the size of the head of the implant projected on to the radiographs and comparing the result with the known size recorded in the medical records.

The accuracy was found to be similar with a mean absolute measurement error of 2.6% (sd 1.4; 0.0% to 5.2%) for the radiological marker and 2.8% (sd 2.2; 0.4% to 10.1%) for the distance method (p = 0.75). The mean radiation dose for templating radiographs (pelvis and lateral of the hip) was similar when taken using a radiological marker (328 mSv sd 142) (n = 51) or using the distance measurement method (324 mSv sd 39) (n = 39) (p = 0.90).

We conclude that the distance measuring method is as accurate as the radiological marker method, but may avoid some of the disadvantages such as misplacement of the marker or placement outside the radiological field. It may also be more acceptable to the patient and radiographer.

We analysed which pre-operative factors could be used to predict the length of in-patient stay following unilateral primary total hip replacement undertaken for osteoarthritis. Data were collected prospectively from 2302 patients undergoing primary total hip replacement over a nine-year period. The relationships between the various pre-operative factors and length of stay were studied separately using either Student’s t-test or Pearson’s correlation, and then subjected to multiple linear regression analysis.

The mean length of stay was 8.1 days (median 7; 3 to 58). After adjusting for the effects of other pre-operative factors, younger age, male gender, higher combined Harris hip function and activity score, higher general health perception dimension of the Short-Form 36 score, and non-steroidal anti-inflammatory drug use were all found to be significantly associated with a reduced length of stay.

We have reviewed the rate of revision of fully cemented, hybrid and uncemented primary total hip replacements (THRs) registered in the New Zealand Joint Registry between 1999 and December 2006 to determine whether there was any statistically significant difference in the early survival and reason for revision in these different types of fixation. The percentage rate of revision was calculated per 100 component years and compared with the reason for revision, the type of fixation and the age of the patients.

Of the 42 665 primary THRs registered, 920 (2.16%) underwent revision requiring change of at least one component. Fully-cemented THRs had a lower rate of revision when considering all causes for failure (p < 0.001), but below the age of 65 years uncemented THRs had a lower rate (p < 0.01). The rate of revision of the acetabular component for aseptic loosening was less in the uncemented and hybrid groups compared with that in the fully cemented group (p < 0.001), and the rate of revision of cemented and uncemented femoral components was similar, except in patients over 75 years of age in whom revision of cemented femoral components was significantly less frequent (p < 0.02). Revision for infection was more common in patients aged below 65 years and in cemented and hybrid THRs compared with cementless THRs (p < 0.001). Dislocation was the most common cause of revision for all types of fixation and was more frequent in both uncemented acetabular groups (p < 0.001). The experience of the surgeon did not affect the findings.

Although cemented THR had the lowest rate of revision for all causes in the short term (90 days), uncemented THR had the lowest rate of aseptic loosening in patients under 65 years of age and had rates comparable with international rates of aseptic loosening in those over 65 years.

We have studied the natural history of a first episode of dislocation after primary total hip replacement (THR) to clarify the incidence of recurrent dislocation, the need for subsequent revision and the quality of life of these patients.

Over a six-year period, 99 patients (101 hips) presented with a first dislocation of a primary THR. A total of 61 hips (60.4%) had dislocated more than once. After a minimum follow-up of one year, seven patients had died. Of the remaining 94 hips (92 patients), 47 underwent a revision for instability and one awaits operation (51% in total). Of these, seven re-dislocated and four needed further surgery. The quality of life of the patients was studied using the Oxford Hip Score and the EuroQol-5 Dimension (EQ-5D) questionnaire. A control group of patients who had not dislocated was also studied. At a mean follow-up of 4.5 years (1 to 20), the mean Oxford Hip Score was 26.7 (15 to 47) after one episode of dislocation, 27.2 (12 to 45) after recurrent dislocation, 34.5 (12 to 54) after successful revision surgery, 42 (29 to 55) after failed revision surgery and 17.4 (12 to 32) in the control group. The EuroQol-5 dimension questionnaire revealed more health problems in patients undergoing revision surgery.

We reviewed 111 hemispherical Duraloc series-500 acetabular components with a minimum follow-up of 12 years. The mean clinical and radiological follow-up was 13.4 years (12 to 15). A Profile hydroxyapatite-coated anatomical femoral component was used in each case. Six patients had a late dislocation, for whom the polyethylene liner was exchanged. Each acetabular component was well fixed and all femoral components showed signs of bone ingrowth. The mean rate of femoral head penetration was 0.10 mm/year (0.021 to 0.481). The probability of not developing femoral cortical hypertrophy and proximal osteopenia by 12 years was 80.2% (95% confidence interval, 72.7 to 87.6) and 77.5% (95% confidence interval, 69.7 to 85.2), respectively. Despite these good clinical results, further follow-up is needed to determine whether these prostheses will loosen with time.

We have investigated the accuracy of placement of the femoral component using imageless navigation in 100 consecutive Birmingham Hip Resurfacings. Pre-operative templating determined the native neck-shaft angle and planned stem-shaft angle of the implant. The latter were verified post-operatively using digital anteroposterior unilateral radiographs of the hip.

The mean neck-shaft angle determined before operation was 132.7° (118° to 160°). The mean planned stem-shaft angle was a relative valgus alignment of 9.7° (sd 2.6). The stem-shaft angle after operation differed from that planned by a mean of 2.8° (sd 2.0) and in 86% of cases the final angle measured within ± 5° of that planned. We had no instances of notching of the neck or varus alignment of the implant in our series. A learning curve was observed in the time taken for navigation, but not for accurate placement of the implant.

Navigation in hip resurfacing may afford the surgeon a reliable and accurate method of placement of the femoral component.

We describe 129 consecutive revision total hip replacements using a Charnley-Kerboull femoral component of standard length with impaction allografting. The mean follow-up was 8.2 years (2 to 16). Additionally, extramedullary reinforcement was performed using struts of cortical allograft in 49 hips and cerclage wires in 30.

There was one intra-operative fracture of the femur but none later. Two femoral components subsided by 5 mm and 8 mm respectively, and were considered to be radiological failures. No further revision of a femoral component was required. The rate of survival of the femoral component at nine years, using radiological failure as the endpoint, was 98%. Our study showed that impaction grafting in association with a Charnley-Kerboull femoral component has a low rate of subsidence. Reconstruction of deficiencies of distal bone with struts of cortical allograft appeared to be an efficient way of preventing postoperative femoral fracture for up to 16 years.

We investigated whether simultaneous bilateral sequential total hip replacement (THR) would increase the rate of mortality and complications compared with unilateral THR in both low- and high-risk groups of patients.

We enrolled 978 patients with bilateral and 1666 with unilateral THR in the study. There were no significant pre-operative differences between the groups in regard to age, gender, body mass index, diagnosis, comorbidity as assessed by the grading of the American Society of Anesthesiologists (ASA), the type of prosthesis and the duration of follow-up. The mean follow-up was for 10.5 years (5 to 13) in the bilateral THR group and 9.8 years (5 to 14) in the unilateral group.

The peri-operative mortality rate of patients who had simultaneous bilateral THR (0.31%, three of 978 patients) was similar to that of patients with unilateral THR (0.18%, three of 1666 patients). The peri-operative mortality rate of patients in the bilateral group was similar in high risk and low risk patients (0.70%, two of 285 patients vs 0.14%, one of 693 patients) and this was also true in the unilateral THR group (0.40%, two of 500 patients vs 0.09%, one of 1166 patients). Patients with bilateral THR required more blood transfusions and a longer hospital stay than those in the unilateral THR group. There was no significant difference (p = 0.32) in the overall number of complications between the groups. This was also true for the low-risk (p = 0.81) vs high-risk (p = 0.631) patients.

Our findings confirm that simultaneous sequential bilateral THR is a safe option for patients who are considered to be either high or low risk according to the ASA classification.

In Africa the amount of joint replacement surgery is increasing, but the indications for operation and the age of the patients are considerably different from those in the developed world. New centres with variable standards of care and training of the surgeons are performing these procedures and it is important that a proper audit of this work is undertaken.

In Malawi, we have pioneered a Registry which includes all joint replacements that have been carried out in the country. The data gathered include the age, gender, indication for operation, the prosthesis used, the surgical approach, the use of bone graft, the type of cement, pressurising systems and the thromboprophylaxis used. All patients have their clinical scores recorded pre-operatively and then after three and six months and at one year. Before operation all patients are counselled and on consent their HIV status is established allowing analysis of the effect of HIV on successful joint replacement.

To date, 73 total hip replacements (THRs) have been carried out in 58 patients by four surgeons in four different hospitals. The most common indications for THR were avascular necrosis (35 hips) and osteoarthritis (22 hips). The information concerning 20 total knee replacements has also been added to the Registry.

Pre-operative computerised three-dimensional planning was carried out in 223 patients undergoing total hip replacement with a cementless acetabular component and a cementless modular-neck femoral stem. Components were chosen which best restored leg length and femoral offset. The post-operative restoration of the anatomy was assessed by CT and compared with the pre-operative plan.

The component implanted was the same as that planned in 86% of the hips for the acetabular implant, 94% for the stem, and 93% for the neck-shaft angle. The rotational centre of the hip was restored with a mean accuracy of 0.73 mm (sd 3.5) craniocaudally and 1.2 mm (sd 2) laterally. Limb length was restored with a mean accuracy of 0.3 mm (sd 3.3) and femoral offset with a mean accuracy of 0.8 mm (sd 3.1).

This method appears to offer high accuracy in hip reconstruction as the difficulties likely to be encountered when restoring the anatomy can be anticipated and solved pre-operatively by optimising the selection of implants. Modularity of the femoral neck helped to restore the femoral offset and limb length.

We describe the findings at six years in an ongoing prospective clinicoradiological and metal ion study in a cohort of 26 consecutive male patients with unilateral Birmingham Hip Resurfacing arthroplasties with one of two femoral head sizes (50 mm and 54 mm). Their mean age was 52.9 years (29 to 67). We have previously shown an early increase in the 24-hour urinary excretion of metal ions, reaching a peak at six months (cobalt) and one year (chromium) after operation. Subsequently there is a decreasing trend in excretion of both cobalt and chromium. The levels of cobalt and chromium in whole blood also show a significant increase at one year, followed by a decreasing trend until the sixth year.