We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81). We defined peri-prosthetic infection as an increased uptake of radioisotope in all the phases of triple-phase bone scintigraphy and validated these results against the histological and/or microbiology results in every case.

The positive and negative predictive values for the presence of infection were 83% and 93%, respectively. The diagnostic sensitivity was 88% and the specificity was 90%.

This study indicates that triple-phase bone scintigraphy is a useful tool in the detection of peri-prosthetic infection and offers a cost-effective method of screening.

We reviewed 25 patients in whom a MUTARS megaprosthesis with a conical fluted stem had been implanted. There were three types of stem: a standard stem was used in 17 cases (three in the proximal femur, nine in the distal femur and five proximal tibia), a custom-made proximal femoral stem in four cases and a custom-made distal femoral stem in four cases. The mean age of the patients was 40.1 years (17 to 70) and the mean follow-up was for 2.5 years (0.9 to 7.4).

At follow-up two patients had died from their disease: one was alive with disease and 22 were disease-free. One of 23 prostheses had been removed for infection and another revised to a cemented stem. The mean Musculoskeletal Tumor Society score was 24.9 (12 to 30) and the mean Karnofsky index was 82% (60% to 100%).

There was no radiological evidence of loosening or subsidence. Stem stress shielding was seen in 11 patients and was marked in five of these.

There were five complications, rupture of the extensor mechanism of the knee after extra-articular resection in two patients, deep venous thrombosis in one, septic loosening in one, and dislocation of the hip in one.

The survival rate after seven years was 87% (95% confidence interval (CI) 83 to 91) for the patients and 95% (95% CI 91 to 99) for the megaprosthesis. A longer follow-up is needed to confirm these encouraging results.

This paper considers the new financial infrastructure of the National Health Service and provides a resource for orthopaedic surgeons. We describe the importance of accurate documentation and data collection for National Health Service hospital Trust finances and league tables, and support our discussion with examples drawn from our local audit work.

Failure of fixation is a common problem in the treatment of osteoporotic fractures around the hip. The reinforcement of bone stock or of fixation of the implant may be a solution. Our study assesses the existing evidence for the use of bone substitutes in the management of these fractures in osteoporotic patients. Relevant publications were retrieved through Medline research and further scrutinised. Of 411 studies identified, 22 met the inclusion criteria, comprising 12 experimental and ten clinical reports. The clinical studies were evaluated with regard to their level of evidence. Only four were prospective and randomised.

Polymethylmethacrylate and calcium-phosphate cements increased the primary stability of the implant-bone construct in all experimental and clinical studies, although there was considerable variation in the design of the studies. In randomised, controlled studies, augmentation of intracapsular fractures of the neck of the femur with calcium-phosphate cement was associated with poor long-term results. There was a lack of data on the long-term outcome for trochanteric fractures. Because there were only a few, randomised, controlled studies, there is currently poor evidence for the use of bone cement in the treatment of fractures of the hip.

While frequently discussed as a standard treatment for the management of an infected shoulder replacement, there is little information on the outcome of two-stage re-implantation.

We examined the outcome of 17 consecutive patients (19 shoulders) who were treated between 1995 and 2004 with a two-stage re-implantation for the treatment of a deep-infection after shoulder replacement. All 19 shoulders were followed for a minimum of two years or until the time of further revision surgery. The mean clinical follow-up was for 35 months (24 to 80). The mean radiological follow-up was 27 months (7 to 80). There were two excellent results, four satisfactory and 13 unsatisfactory. In 12 of the 19 shoulders (63%) infection was considered to be eradicated. The mean pain score improved from 4.2 (3 to 5 (out of 5)) to 1.8 (1 to 4). The mean elevation improved from 42° (0° to 140°) to 89° (0° to 165°), mean external rotation from 30° (0° to 90°) to 43° (0° to 90°), and mean internal rotation from the sacrum to L5. There were 14 complications.

Our study suggests that two-stage re-implantation for an infected shoulder replacement is associated with a high rate of unsatisfactory results, marginal success at eradicating infection and a high complication rate.

Multiple drilling is reported to be an effective treatment for osteonecrosis of the head of femur, but its effect on intra-osseous pressure has not been described. We undertook multiple drilling and recorded the intra-osseous pressure in 75 osteonecrotic hips in 60 patients with a mean age of 42 years (19 to 67). At a mean follow-up of 37.1 months (24 to 60), 42 hips (56%) had a clinically successful outcome. The procedure was effective in reducing the mean intra-osseous pressure from 57 mmHg (SD 22) to 16 mmHg (SD 9). Hips with a successful outcome had a mean pressure of 26 mmHg (SD 19). It was less effective in preventing progression of osteonecrosis in hips with considerable involvement and in those with a high intra-osseous pressure in the intertrochanteric region (mean 45 mmHg (SD 25)). This study is not able to answer whether a return of the intra-osseous pressure to normal levels is required for satisfactory healing.

We report our early experience with a new peri-acetabular reconstruction endoprosthesis used for pelvic reconstruction after tumour resection. The outcome of 21 patients who underwent limb salvage following type II pelvic resection and reconstruction using the peri-acetabular reconstruction prosthesis between 2000 and 2006 was retrospectively reviewed. This prosthesis was designed to use the remaining part of the ilium to support a horizontally placed acetabular component secured with internal fixation and bone cement. Into this device a constrained acetabular liner is positioned which is articulates with a conventional femoral component to which a modular extension and modular head are attached. The mean follow-up was 20.5 months (1 to 77). The most common complications were deep infection, superficial wound infections, and dislocation. The mean musculoskeletal tumor society functional outcome score for the survivors was 20.1(11 to 27).

We recommend the use of the peri-acetabular reconstruction prosthesis for reconstruction of large defects after type II pelvic resection, as this design has a greater inherent stability over other available prostheses.

Few independent studies have reported the outcome of resurfacing arthroplasty of the hip. The aim of this study was to report the five-year clinical outcome and seven-year survival of an independent series.

A total of 610 Birmingham Hip Resurfacing arthroplasties were performed in 532 patients with a mean age of 51.8 years (16.5 to 81.6). They were followed for between two and eight years; 107 patients (120 hips) had been followed up for more than five years. Two patients were lost to follow-up. At a minimum of five years’ follow-up, 79 of 85 hips (93%) had an excellent or good outcome according to the Harris hip score. The mean Oxford hip score was 16.1 points (sd 7.7) and the mean University of California Los Angeles activity score was 6.6 points (sd 1.9). There were no patients with definite radiological evidence of loosening or of narrowing of the femoral neck exceeding 10% of its width. There were 23 revisions (3.8%), giving an overall survival of 95% (95% confidence interval 85.3 to 99.2) at seven years. Fractured neck of femur in 12 hips was the most common indication for revision, followed by aseptic loosening in four. In three hips (three patients) (0.5%), failure was possibly related to metal debris.

Considering that these patients are young and active these results are good, and support the use of resurfacing. Further study is needed to address the early failures, particularly those related to fracture and metal debris.

A cadaver study using six pairs of lower limbs was conducted to investigate the accuracy of computer navigation and standard instrumentation for the placement of the Birmingham Hip Resurfacing femoral component. The aim was to place all the femoral components with a stem-shaft angle of 135°.

The mean stem-shaft angle obtained in the standard instrumentation group was 127.7° (120° to 132°), compared with 133.3° (131° to 139°) in the computer navigation group (p = 0.03). The scatter obtained with computer-assisted navigation was approximately half that found using the conventional jig.

Computer navigation was more accurate and more consistent in its placement of the femoral component than standard instrumentation. We suggest that image-free computer-assisted navigation may have an application in aligning the femoral component during hip resurfacing.

Modifications in the design of knee replacements have been proposed in order to maximise flexion. We performed a prospective double-blind randomised controlled trial to compare the functional outcome, including maximum knee flexion, in patients receiving either a standard or a high flexion version of the NexGen legacy posterior stabilised total knee replacement. A total of 56 patients, half of whom received each design, were assessed pre-operatively and at one year after operation using knee scores and analysis of range of movement using electrogoniometry. For both implant designs there was a significant improvement in the function component of the knee scores (p < 0.001) and the maximum range of flexion when walking on the level, ascending and descending a slope or stairs (all p < 0.001), squatting (p = 0.020) and stepping into a bath (p = 0.024). There was no significant difference in outcome, including the maximum knee flexion, between patients receiving the standard and high flexion designs of this implant.

The dysplasia cup, which was devised as an adjunct to the Birmingham Hip Resurfacing system, has a hydroxyapatite-coated porous surface and two supplementary neutralisation screws to provide stable primary fixation, permit early weight-bearing, and allow incorporation of morcellised autograft without the need for structural bone grafting.

A total of 110 consecutive dysplasia resurfacing arthroplasties in 103 patients (55 men and 48 women) performed between 1997 and 2000 was reviewed with a minimum follow-up of six years. The mean age at operation was 47.2 years (21 to 62) and 104 hips (94%) were Crowe grade II or III.

During the mean follow-up of 7.8 years (6 to 9.6), three hips (2.7%) were converted to a total hip replacement at a mean of 3.9 years (2 months to 8.1 years), giving a cumulative survival of 95.2% at nine years (95% confidence interval 89 to 100). The revisions were due to a fracture of the femoral neck, a collapse of the femoral head and a deep infection. There was no aseptic loosening or osteolysis of the acetabular component associated with either of the revisions performed for failure of the femoral component. No patient is awaiting a revision.

The median Oxford hip score in 98 patients with surviving hips at the final review was 13 and the 10th and the 90th percentiles were 12 and 23, respectively.

We have examined the results obtained with 72 NexGen legacy posterior stabilised-flex fixed total knee replacements in 47 patients implanted by a single surgeon between March 2003 and September 2004.

Aseptic loosening of the femoral component was found in 27 (38%) of the replacements at a mean follow-up of 32 months (30 to 48) and 15 knees (21%) required revision at a mean of 23 months (11 to 45). We compared the radiologically-loose and revised knees with those which had remained well-fixed to identify the factors which had contributed to this high rate of aseptic loosening.

Post-operatively, the mean maximum flexion was 136° (110° to 140°) in the loosened group and 125° (95° to 140°) in the well-fixed group (independent t-test, p = 0.022). Squatting, kneeling, or sitting cross-legged could be achieved by 23 (85%) of the loosened knees, but only 22 (49%) of the well-fixed knees (chi-squared test, p = 0.001). The loosened femoral components were found to migrate into a more flexed position, but no migration was detected in the well-fixed group.

These implants allowed a high degree of flexion, but showed a marked rate of early loosening of the femoral component, which was associated with weight-bearing in maximum flexion.

We investigated the relationship of the inferior gluteal nerve to gluteus maximus by dissecting the muscle in 12 fresh-frozen and formalin-treated cadavers. The anatomy was recorded using still digital photography. The course of the inferior gluteal nerve was carefully traced and was noted to enter the deep surface of gluteus maximus approximately 5 cm from the tip of the greater trochanter of the femur. The susceptibility of the nerve to injury during a posterior approach to the hip may be explained by its close relationship to the deep surface of gluteus maximus. It is easily damaged before it has been seen if the muscle is split and parted more than 5 cm from the tip of the greater trochanter of the femur. We suggest that a modified posterior approach be used to expose the hip to avoid damage to this nerve.

Peri- and sub-prosthetic fractures, or pathological fractures below an existing well-fixed femoral component, with or without an ipsilateral knee replacement, present a difficult surgical challenge.

We describe a simple solution, in which a custom-made prosthesis with a cylindrical design is cemented proximally to the stem of an existing, well-fixed femoral component. This effectively treats the fracture without sacrificing the good hip. We describe five patients with a mean age of 73 years (60 to 81) and a mean follow-up of 47 months (6 to 108).

The mean overlap of the prosthesis over the femoral component was 7.5 cm (5.5 to 10). There have been no mechanical failures, no new infections and no re-operations. We suggest that in highly selected cases, in which conventional fixation is not feasible, this technique offers a durable option and avoids the morbidity of a total femoral replacement.

Nanometre-sized particles of ultra-high molecular weight polyethylene have been identified in the lubricants retrieved from hip simulators. Tissue samples were taken from seven failed Charnley total hip replacements, digested using strong alkali and analysed using high-resolution field emission gun-scanning electron microscopy to determine whether nanometre-sized particles of polyethylene debris were generated in vivo. A randomised method of analysis was used to quantify and characterise all the polyethylene particles isolated.

We isolated nanometre-sized particles from the retrieved tissue samples. The smallest identified was 30 nm and the majority were in the 0.1 μm to 0.99 μm size range. Particles in the 1.0 μm to 9.99 μm size range represented the highest proportion of the wear volume of the tissue samples, with 35% to 98% of the total wear volume comprised of particles of this size. The number of nanometre-sized particles isolated from the tissues accounted for only a small proportion of the total wear volume. Further work is required to assess the biological response to nanometre-sized polyethylene particles.

Patients considered suitable for total hip resurfacing arthroplasty often have bilateral disease. The peri-operative complications, transfusion requirements, hospital stay, outcome and costs in patients undergoing one-stage bilateral total hip resurfacing were compared with a group of patients undergoing a two-stage procedure. A total of 92 patients were included in the study, of which 37 (40%) had a one-stage and 55 (60%) had a two-stage resurfacing. There were no significant differences in age, gender, or American Society of Anaesthesiologists grade between the groups (p = 0.31, p = 0.23, p = 0.13, respectively). There were three systemic complications in the one-stage group (8.1%) and one in the two-stage group (1.8% of patients; 0.9% of procedures). There was no significant difference in the complication rate (p = 0.72) or the transfusion requirements (p = 0.32) between the two groups. The one-stage group had a reduced total hospital stay of five days (95% confidence interval 4.0 to 6.9; p < 0.001), reduced length of time to completion of all surgery of five months (95% confidence interval 2.6 to 8.3; p < 0.001), and the reduced cost was 35% less than that of a two-stage procedure. However, the total anaesthetic time was significantly longer for the one-stage group (p < 0.001; 95% confidence interval 31 to 52).

This study demonstrates that consideration should be given to one-stage surgery for patients with bilateral symptomatic disease suitable for metal-on-metal hip resurfacing. A one-stage procedure appears to have benefits for both the patient and the hospital without additional complications.

We have studied the effect of shortening of the femoral neck and varus collapse on the functional capacity and quality of life of patients who had undergone fixation of an isolated intracapsular fracture of the hip with cancellous screws. After screening 660 patients at four university medical centres, 70 patients with a mean age of 71 years (20 to 90) met the inclusion criteria. Overall, 66% (46 of 70) of the fractures healed with > 5 mm of shortening and 39% (27 of 70) with > 5° of varus. Patients with severe shortening of the femoral neck had significantly lower short form-36 questionnaire (SF-36) physical functioning scores (no/mild (< 5 mm) vs severe shortening (> 10 mm); 74 vs 42 points, p < 0.001). A similar effect was noted with moderate shortening, suggesting a gradient effect (no/mild (< 5 mm) vs moderate shortening (5 to 10 mm); 74 vs 53 points, p = 0.011). Varus collapse correlated moderately with the occurrence of shortening (r = 0.66, p < 0.001). Shortening also resulted in a significantly lower EuroQol questionnaire (EQ5D) index scores (p = 0.05). In a regression analysis shortening of the femoral neck was the only significant variable predictive of a low SF-36 physical functioning score (p < 0.001).