The purpose of this paper is to discuss the risk factors, prevention strategies, classification, and treatment of intra-operative femur fractures sustained during primary and revision total hip arthroplasty.

There are no recent studies comparing cable with wire for the fixation of osteotomies or fractures in total hip replacement (THR). Our objective was to evaluate the five-year clinical and radiological outcomes and complication rates of the two techniques. We undertook a review including all primary and revision THRs performed in one hospital between 1996 and 2005 using cable or wire fixation. Clinical and radiological evaluation was performed five years post-operatively. Cables were used in 51 THRs and wires in 126, and of these, 36 THRs with cable (71%) and 101 with wire (80%) were evaluated at follow-up. The five-year radiographs available for 33 cable and 91 wire THRs revealed rates of breakage of fixation of 12 of 33 (36%) and 42 of 91 (46%), respectively. With cable there was a significantly higher risk of metal debris (68% vs 9%; adjusted relative risk (RR) 6.6; 95% confidence interval (CI) 3.0 to 14.1), nonunion (36% vs 21%; adjusted RR 2.0; 95% CI 1.0 to 3.9) and osteolysis around the material, acetabulum or femur (61% vs 19%; adjusted RR 3.9; 95% CI 2.3 to 6.5). Cable breakage increased the risk of osteolysis to 83%. There was a trend towards foreign-body reaction and increased infection with cables. Clinical results did not differ between the groups.

In conclusion, we found a higher incidence of complications and a trend towards increased infection and foreign-body reaction with the use of cables.

Revision arthroplasty of the hip is expensive owing to the increased cost of pre-operative investigations, surgical implants and instrumentation, protracted hospital stay and drugs. We compared the costs of performing this surgery for aseptic loosening, dislocation, deep infection and peri-prosthetic fracture. Clinical, demographic and economic data were obtained for 305 consecutive revision total hip replacements in 286 patients performed at a tertiary referral centre between 1999 and 2008. The mean total costs for revision surgery in aseptic cases (n = 194) were £11 897 (sd 4629), for septic revision (n = 76) £21 937 (sd 10 965), for peri-prosthetic fracture (n = 24) £18 185 (sd 9124), and for dislocation (n = 11) £10 893 (sd 5476). Surgery for deep infection and peri-prosthetic fracture was associated with longer operating times, increased blood loss and an increase in complications compared to revisions for aseptic loosening. Total inpatient stay was also significantly longer on average (p < 0.001). Financial costs vary significantly by indication, which is not reflected in current National Health Service tariffs.

Two-stage revision surgery for infected total knee replacement offers the highest rate of success for the elimination of infection. The use of articulating antibiotic-laden cement spacers during the first stage to eradicate infection also allows protection of the soft tissues against excessive scarring and stiffness. We have investigated the effect of cyclical loading of cement spacers on the elution of antibiotics. Femoral and tibial spacers containing vancomycin at a constant concentration and tobramycin of varying concentrations were studied in vitro. The specimens were immersed and loaded cyclically to 250 N, with a flexion excursion of 45°, for 35 000 cycles. The buffered solution was sampled at set intervals and the antibiotic concentration was established so that the elution could be calculated. Unloaded samples were used as a control group for statistical comparison.

The elution of tobramycin increased proportionately with its concentration in cement and was significantly higher at all sampling times from five minutes to 1680 minutes in loaded components compared with the control group (p = 0.021 and p = 0.003, respectively). A similar trend was observed with elution of vancomycin, but this failed to reach statistical significance at five, 1320 and 1560 minutes (p = 0.0508, p = 0.067 and p = 0.347, respectively). However, cyclically loaded and control components showed an increased elution of vancomycin with increasing tobramycin concentration in the specimens, despite all components having the same vancomycin concentration. The concentration of tobramycin influences both tobramycin and vancomycin elution from bone cement. Cyclical loading of the cement spacers enhanced the elution of vancomycin and tobramycin.

Retrieval studies of total hip replacements with highly cross-linked ultra-high-molecular-weight polyethylene liners have shown much less surface damage than with conventional ultra-high-molecular-weight polyethylene liners. A recent revision hip replacement for recurrent dislocation undertaken after only five months revealed a highly cross-linked polyethylene liner with a large area of visible delamination. In order to determine the cause of this unusual surface damage, we analysed the bearing surfaces of the cobalt-chromium femoral head and the acetabular liner with scanning electron microscopy, energy dispersive x-ray spectroscopy and optical profilometry. We concluded that the cobalt-chromium modular femoral head had scraped against the titanium acetabular shell during the course of the dislocations and had not only roughened the surface of the femoral head but also transferred deposits of titanium onto it. The largest deposits were 1.6 μm to 4.3 μm proud of the surrounding surface and could lead to increased stresses in the acetabular liner and therefore cause accelerated wear and damage.

This case illustrates that dislocations can leave titanium deposits on cobalt-chromium femoral heads and that highly cross-linked ultra-high-molecular-weight polyethylene remains susceptible to surface damage.

We report the results of 79 patients (81 hips) who underwent impaction grafting at revision hip replacement using the Exeter femoral stem. Their mean age was 64 years (31 to 83). According to the Endoklinik classification, 20 hips had a type 2 bone defect, 40 had type 3, and 21 had type 4. The mean follow-up for unrevised stems was 10.4 years (5 to 17).

There were 12 re-operations due to intra- and post-operative fractures, infection (one hip) and aseptic loosening (one hip). All re-operations affected type 3 (6 hips) and 4 (6 hips) bone defects. The survival rate for re-operation for any cause was 100% for type 2, 81.2% (95% confidence interval (CI) 67.1 to 95.3) for type 3, and 70.8% (95% CI 51.1 to 90.5) for type 4 defects at 14 years. The survival rate with further revision for aseptic loosening as the end point was 98.6% (95% CI 95.8 to 100). The final clinical score was higher for patients with type 2 bone defects than type 4 regarding pain, function and range of movement. Limp was most frequent in the type 4 group (p < 0.001). The mean subsidence of the stem was 2.3 mm (sd 3.7) for hips with a type 2 defect, 4.3 mm (sd 7.2) for type 3 and 9.6 mm (sd 10.8) for type 4 (p = 0.022).

The impacted bone grafting technique has good clinical results in femoral revision. However, major bone defects affect clinical outcome and also result in more operative complications.

The clinical and radiological results of 50 consecutive acetabular reconstructions in 48 patients using impaction grafting have been retrospectively reviewed. A 1:1 mixture of frozen, ground irradiated bone graft and Apapore 60, a synthetic bone graft substitute, was used in all cases. There were 13 complex primary and 37 revision procedures with a mean follow-up of five years (3.4 to 7.6). The clinical survival rate was 100%, with improvements in the mean Harris Hip Scores for pain and function. Radiologically, 30 acetabular grafts showed evidence of incorporation, ten had radiolucent lines and two acetabular components migrated initially before stabilising.

Acetabular reconstruction in both primary and revision surgery using a 1:1 mixture of frozen, ground, irriadiated bone and Apapore 60 appears to be a reliable method of managing acetabular defects. Longer follow-up will be required to establish whether this technique is as effective as using fresh-frozen allograft.

We investigated the early results of modular porous metal components used in 23 acetabular reconstructions associated with major bone loss. The series included seven men and 15 women with a mean age of 67 years (38 to 81), who had undergone a mean of two previous revisions (1 to 7).

Based on Paprosky’s classification, there were 17 type 3A and six type 3B defects. Pelvic discontinuity was noted in one case. Augments were used in 21 hips to support the shell and an acetabular component-cage construct was implanted in one case. At a mean follow-up of 41 months (24 to 62), 22 components remained well fixed. Two patients required rerevision of the liners for prosthetic joint instability. Clinically, the mean Harris Hip Score improved from 43.0 pre-operatively (14 to 86) to 75.7 post-operatively (53 to 100). The mean pre-operative Merle d’Aubigné score was 8.2 (3 to 15) and improved to a mean of 13.7 (11 to 18) post-operatively.

These short-term results suggest that modular porous metal components are a viable option in the reconstruction of Paprosky type 3 acetabular defects. More data are needed to determine whether the system yields greater long-term success than more traditional methods, such as reconstruction cages and structural allografts.

We present an update of the clinical and radiological results of 62 consecutive acetabular revisions using impacted morsellised cancellous bone grafts and a cemented acetabular component in 58 patients, at a mean follow-up of 22.2 years (20 to 25). The Kaplan-Meier survivorship for the acetabular component with revision for any reason as the endpoint was 75% at 20 years (95% confidence interval (CI) 62 to 88) when 16 hips were at risk. Excluding two revisions for septic loosening at three and six years, the survivorship at 20 years was 79% (95% CI 67 to 93). With further exclusions of one revision of a well-fixed acetabular component after 12 years during a femoral revision and two after 17 years for wear of the acetabular component, the survivorship for aseptic loosening was 87% at 20 years (95% CI 76 to 97). At the final review 14 of the 16 surviving hips had radiographs available. There was one additional case of radiological loosening and four acetabular reconstructions showed progressive radiolucent lines in one or two zones.

Acetabular revision using impacted large morsellised bone chips (0.5 cm to 1 cm in diameter) and a cemented acetabular component remains a reliable technique for reconstruction, even when assessed at more than 20 years after surgery.

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.

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.

We studied survival to 38 years after Charnley low-friction arthroplasty of the hip. We used revision as an end-point, while adopting a policy of regular follow-up and early revision for radiological changes alone if indicated.

Between November 1962 and June 2005, 22 066 primary low-friction arthroplasties (17 409 patients) had been performed at Wrightington Hospital by more than 330 surgeons. By June 2006, 1001 (4.5%) hips had been revised and 1490 patients (2662 hips, 12%) had died. At 31 years, where a minimum of 40 hips were still attending follow-up, survival with revision for infection as an endpoint was 95%, for dislocation 98%, for a fractured stem 88.6%, for a loose stem 72.5% and for a loose acetabular component 53.7%. Wear and loosening of the ultra-high-molecular-weight polyethylene acetabular component were the main long-term problems.

We conclude that regular follow-up after hip replacement is essential and that all operative findings should be recorded at revision.

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.

Between 1980 and 2000, 63 support rings were used in the management of acetabular deficiency in a series of 60 patients, with a mean follow-up of 8.75 years (2 months to 23.8 years). There was a minimum five-year follow-up for successful reconstructions. The indication for revision surgery was aseptic loosening in 30 cases and infection in 33. All cases were Paprosky III defects; IIIA in 33 patients (52.4%) and IIIB in 30 (47.6%), including four with pelvic dissociation. A total of 26 patients (43.3%) have died since surgery, and 34 (56.7%) remain under clinical review. With acetabular revision for infection or aseptic loosening as the definition of failure, we report success in 53 (84%) of the reconstructions. A total of 12 failures (19%) required further surgery, four (6.3%) for aseptic loosening of the acetabular construct, six (9.5%) for recurrent infection and two (3.2%) for recurrent dislocation requiring captive components. Complications, seen in 11 patients (18.3%), included six femoral or sciatic neuropraxias which all resolved, one grade III heterotopic ossification, one on-table acetabular revision for instability, and three early post-operative dislocations managed by manipulation under anaesthesia, with no further instability.

We recommend support rings and morcellised bone graft for significant acetabular bone deficiency that cannot be reconstructed using mesh.

We have managed 27 patients (16 women and 11 men) with a mean age of 68.4 years (50 to 84), with failed total hip replacement and severe proximal femoral bone loss by revision using a distal fix/proximal wrap prosthesis. The mean follow-up was for 55.3 months (25 to 126). The mean number of previous operations was 2.2 (1 to 4). The mean Oxford hip score decreased from 46.2 (38 to 60) to 28.5 (17 to 42) (paired t-test, p < 0.001) and the mean Harris Hip score increased from 30.4 (3 to 57.7) to 71.7 (44 to 99.7) (paired t-test, p < 0.001). There were two dislocations, and in three patients we failed to eradicate previous infection. None required revision of the femoral stem.

This technique allows instant distal fixation while promoting biological integration and restoration of bone stock. In the short term, the functional outcome is encouraging and the complication rates acceptable in this difficult group of patients.

Polyethylene wear of acetabular components is a key factor in the development of periprosthetic osteolysis and wear at the articular surface has been well documented and quantified, but fewer data are available about changes which occur at the backside of the liner.

At revision surgery for loosening of the femoral component we retrieved 35 conventional modular acetabular liners of the same design. Linear and volumetric articular wear, backside volumetric change and the volume of the screw-head indentations were quantified. These volumes, clinical data and the results from radiological Ein Bild Röntgen Analyse migration analysis were used to identify potential factors influencing the volumetric articular wear and backside volumetric change.

The rate of backside volumetric change was found to be 2.8% of the rate of volumetric articular wear and decreased with increasing liner size. Migrated acetabular components showed significantly higher rates of backside volumetric change plus screw-head indentations than those without migration.

The backside volumetric change was at least ten times larger than finite-element simulation had suggested. In a stable acetabular component with well-anchored screws, the amount of backside wear should not cause clinical problems. Impingement of the screw-heads could produce more wear particles than those generated at the liner-shell interface. Because the rate of backside volumetric change is only 2.8% of the rate of volumetric articular wear and since creep is likely to contribute a significant portion to this, the debris generated by wear at the backside of the liner may not be sufficient to create a strong osteolytic response.

We analysed the results of different strategies in the revision of primary uncemented acetabular components reported to the Norwegian Arthroplasty Register. The aim was to compare the risk of further acetabular revision after isolated liner exchange and complete component revision. The results of exchanging well-fixed components were also compared with those of exchanging loose acetabular components. The period studied was between September 1987 and April 2005. The following groups were compared: group 1, exchange of liner only in 318 hips; group 2, exchange of well-fixed components in 398; and group 3, exchange of loose components in 933. We found that the risk of a further cup revision was lower after revision of well-fixed components (relative risk from a Cox model (RR) = 0.56, 95% confidence interval 0.37% to 0.87%) and loose components (RR = 0.56, 95% confidence interval 0.39% to 0.80%), compared with exchange of the liner in isolation. The most frequent reason for a further acetabular revision was dislocation, accounting for 61 (28%) of the re-revisions. Other reasons for further revision included pain in 27 (12%), loosening in 24 (11%) and infection in 20 (9%). Re-revisions because of pain were less frequent when complete component (fixed or loose) revision was undertaken compared with isolated exchange of the liner (RR = 0.20 (95% confidence interval 0.06% to 0.65%) and RR = 0.10 (95% confidence interval 0.03% to 0.30%), respectively). The risk of further acetabular revision for infection, however, did not differ between the groups.

In this study, exchange of the liner only had a higher risk of further cup revision than revision of the complete acetabular component. Our results suggest that the threshold for revising well-fixed components in the case of liner wear and osteolysis should be lowered.

The role of bone-graft extenders in impaction revision surgery is becoming increasingly important. Tricalcium phosphate and hydroxyapatite have been shown to be both biocompatible and osteoconductive, yet many surgeons remain reluctant to use them. The difficulty in handling bone-graft extenders can be partly alleviated by using porous particles and adding clotted blood.

In an in vitro model we measured the cohesive properties of various impaction graft mixes. Several factors were evaluated including the use of pure bone graft compared with mixes with extender, washing the bone and the addition of clotted blood.

Our findings showed that pure allograft bone particles had significantly higher cohesion than when mixed with extender (p < 0.001). Washing had no effect on cohesion. The addition of clotted blood significantly increased the cohesion of both pure bone (p < 0.019) and mixes with pure bone and with porous graft extender (p < 0.044).

Little is known about the efficacy of graduated compression stockings in preventing venous thromboembolism after hip surgery. We conducted a prospective, randomised single-blind study to determine whether the addition of compression stockings to fondaparinux conferred any additional benefit.

The study included 874 patients, of whom 795 could be evaluated (400 in the fondaparinux group and 395 in the fondaparinux plus compression stocking group). Fondaparinux was given post-operatively for five to nine days, either alone or combined with wearing stockings, which were worn for a mean 42 days (35 to 49).

The study outcomes were venous thromboembolism, or sudden death before day 42. Duplex ultrasonography was scheduled within a week of day 42. Safety outcomes were bleeding and death from venous thromboembolism.

The prevalence of deep-vein thrombosis was similar in the two groups 5.5% (22 of 400) in the fondaparinux group and 4.8 (19 of 395) in the fondaparinux plus stocking group (odds ratio 0.88, 95% confidence interval 0.46 to 1.65, p = 0.69). Major bleeding occurred in only one patient.

The addition of graduated compression stockings to fondaparinux appears to offer no additional benefit over the use of fondaparinux alone.

Failure of total hip arthroplasty with acetabular deficiency occurred in 55 patients (60 hips) and was treated with acetabular revision using morsellised allograft and a cemented metal-backed component. A total of 50 patients (55 hips) were available for clinical and radiological evaluation at a mean follow-up of 5.8 years (3 to 9.5). No hip required further revision of the acetabular component because of aseptic loosening.

All the hips except one had complete incorporation of the allograft demonstrated on the radiographs. A complete radiolucent line of > 1 mm was noted in two hips post-operatively. A good to excellent result occurred in 50 hips (91%). With radiological evidence of aseptic loosening of the acetabular component as the end-point, the survivorship at a mean of 5.8 years after surgery was 96.4%.

The use of impacted allograft chips in combination with a cemented metal-backed acetabular component and screw fixation can achieve good medium-term results in patients with acetabular bone deficiency.