Object: To determine whether moderate bone loss in revision total knee arthroplasty can be corrected using an uncemented prosthesis combined with cancellous bone grafting. Methods and results: 23 revision total knee replacements for aseptic loosening or sepsis were undertaken by the senior author between May 1999 and August 2002. All cases involved bone loss of grades F2 and or T2 according to the Anderson Orthopaedic Research Institute Classification (Engh 1998). Bone loss was treated with a mixture of morselized autograft, morselized allograft and bone reamings loosely packed into any contained or uncontained defects following the technique of Whiteside (1992). Uncemented pros-theses with long contact bearing stems were then inserted. All 23 cases were able to partially weight bear immediately postoperatively, indicating satisfactory early press fit. No cases of loosening or cases suspicious of loosening have been noted. Of the 23 cases 19 have been followed for at least 1 year. 18/19 showed consolidation of bone defects and in 1 case there was significant bone resorption under the tibial base plate due to stress shielding. Conclusion: This technique is successful in building up moderate bone loss in revision total knee arthroplasty, therefore avoiding the need for excessive bone resection, large metal augments, mass allografts or custom prostheses

Aim: To determine whether moderate bone loss in revision total knee arthroplasty can be corrected using an uncemented prosthesis combined with cancellous bone grafting. Methods and Patients: 40 revision total knee replacements were undertaken by the senior author between May 1999 and June 2004. 27 one stage revisions for aseptic loosening and 13 two stage revisions for infection. All cases involved bone loss of grades F1/2 and or T1/2 according to the Anderson Orthopaedic Research Institute Classification (Engh 1998). Bone loss was treated with a mixture of morselized autograft, morselized allograft and bone reamings loosely packed into any contained or uncontained defects following the technique of Whiteside (1992). Uncemented prostheses with long contact bearing stems were then inserted. Patients were followed up prospectively with Oxford and HSS knee scores. Results: All 40 cases were able to partially weight bear immediately postoperatively, indicating satisfactory early press fit. No cases of loosening or cases suspicious of loosening have been noted. Mean follow up of 37 months with no patients requiring re revision, no persistent stem pain and no infection in the one stage revisions. 2 cases of infection in the 2 stage group are discussed, neither have required implant removal. Intraoperative and postoperative complications are discussed as well as range of motion, pain and patient satisfaction. In 39/40 cases bone stock has been restored. In 1 case there was significant bone resorption under the tibial base plate due to stress shielding. Conclusions: This technique is successful in building up moderate bone loss in revision total knee arthroplasty, therefore avoiding the need for excessive bone resection, large metal augments, mass allografts or custom made prostheses

Introduction

Infection after total hip arthroplasty is a severe complication. Controversies still exist as to the use of cemented or uncemented implants in the revision of infected THAs. Based on the data in the Norwegian Arthroplasty Register (NAR) we have studied this topic.

Introduction

Total hip arthroplasty (THA) is the only successful treatment for patients in whom the hip joint is destroyed by inflammatory arthritis. Due to the effects of both the disease and its treatment elevated rates of complications and of aseptic loosening have been described. Whether with modern uncemented hip prostheses the results can be improved is not fully known. Therefore, we decided to carry out a prospective study.

Material and methods

At the introduction of a new press-fit acetabular component a prospective study on the results of uncemented THA was started. From 1995 to 1999 85 primary THAs were carried out in 72 patients (57 women, 15 men) suffering from inflammatory arthritis. Diagnosis: RA 76, adult-onset Still 4, JIA 3, miscellaneous 2. Mean age at operation was 60 years (SD 15. 9). Clinically, the Harris Hip Score was used for evaluation. Radiographically, the Larsen classification was used and at follow-up radiolucencies and signs of migration were registered.

The implants used in this study were the EPF-PLUS® acetabular component and the SL-PLUS® femoral component (PLUS Endoprothetik AG, Rotkreuz-CH). The EPF-PLUS® acetabular component is a novel modular press-fit cup. Its shell has a triple radius profile on cross-section, thereby creating a gradual lowering of the polar part of the cup. This produces a small gap of about 2 mm. between the acetabulum and the pole of the cup. Therefore, forces are mainly transmitted to the peripheral part of the acetabulum, leading to an enhanced primary stability. Originally, the shell had a gritblasted surface for osseointegration. Since 1996, the outer surface of the cup has been coated with a ground layer of pure titanium and a superficial layer of a crystalline hydroxyapatite (Ti-HA). The gritblasted version was used in 14 hips (1995–1996), the Ti-HA coated version in 71 hips. In 68 hips the cup was implanted by press-fit fixation, in 17 screws were added.

Results

Larsen classification was as follows: 0-1: 6; 3: 17; 4: 60; 5: 2. At follow-up, 5 patients (6 THAs) were deceased. Deep infection required revision in one hip. Another revision was carried out for recurrent dislocations. One grit-blasted cup developed late subsidence and was revised almost 4 years postoperatively. One Ti-HA coated cup failed early due to severe acetabular bone loss. Finally, one femoral component developed a varus tilt and became symptomatic 2 years after implantation, requiring revision. In all 62 patients with 74 THAs in follow-up cup and stem are functioning well, both clinically and radiographically. Harris Hip Score increased from 36. 6 (SD 17. 7) to 87. 9 (SD 11. 8).

Discussion

The medium-term results of the EPF®-PLUS cup show that its primary stability is good and that, as the polar gap rapidly disappears, osseointegration is secure. Only severe acetabular deficiency appears to be a contra-indication for this implant. Also, the SL-PLUS® stem performs well in inflammatory arthritis.

To compare complications, survivorship and results in 2 groups of Furlong-HAP Active, one with ceramic-ceramic and the other with metal-XLPE friction pair. Prospective, non-randomized, comparison of 2 series of JRI uncemented prosthesis, implanted with identical protocol by 1 surgeon in 1 hospital from 2006 to 2014. Friction pair was ceramic (Biolox Forte or Delta) in 35 patients of 53.7+/−10.6 years (25–69) (21 males, 60%), and CrCo-XLPE in 65 cases of 69.0+/−8.9 years (42–81) (36 males, 55%); there were significant differences in age (p<0.00001) but not in sex (p=0.6565). Head diameter: Ce-Ce with 19 of 28mm, 9 of 32 and 7 of 36mm; Me-PE with 63 of 28mm, 1 of 32 and 1 of 36. Follow-up averaged 10.5+/−3.1 years (1–15) in ceramic and 9.8+/−3.8 years (2–15) in XLPE group. Pearson, Fisher, Kolmogorov-Smirnov, Student, Mann-Whitney, calculated with the informatic tools Microsoft Excel 2007 and . https://www.socscistatistics.com/tests/. . Complications in ceramic joints: 2 late infections (Fisher exact test=0.6101) (1 DAIR, 1 one-stage exchange); 1 dislocation (Fisher exact test=0.2549) (closed reduction); 1 Vancouver C fracture (ORIF) (Fisher exact test=0.6548). Complications in Me-XLPE joints: 2 late infections (Fisher=0.6101) (1 DAIR, 1 two-stage exchange); 7 dislocations (Fisher=0.2549) (2 early, open reduction) (5 late: 3 closed reduction, 1 cup revision, 1 constrained cup); 4 Vancouver B fractures (Fisher=0.6548) (2 intraoperative, cerclages; 2 late, exchange). Final follow-up: Harris Hip Score averaged 93.2+/−13.7 (23–100) in ceramic and 94.3+/−8.7 (65–100) in XLPE joints (p=0.64552). Wear: 0.06+/−0.38mm (0–1.5) in ceramic and 0.16+/−0.5mm (0–2) in Me-PE THAs (p=0.30302). Osteolysis in Charnley-De Lee zones: 8 zones (6 patients) (17%) in ceramic cups, 25 zones (15 patients) (23%) in XLPE cups (p=0.980127). Survivorship without any surgery or closed reduction after 15 years: 91.0% in ceramic joints, 83.8% in Me-XLPE joints. Survivorship without component exchange after 15 years: 93.9% in ceramic joints, 93.6% in Me-XLPE joints. At least after 10 years follow-up of Furlong-HAP Active, metal-XLPE and ceramic-ceramic joints present no significant differences in complications, clinical score, wear, acetabular osteolysis, or survivorship without component exchange. On the contrary, survivorship without any surgery or closed reduction is different because of the high rate of dislocation in 28mm metal-poly joints

Radiostereometric analysis (RSA) is a technique that can be used to measure in-vivo micro-motion of the components of hip arthroplasty. 86 patients received a titanium custom-made prosthesis. The average age was 64 year (20y –84y). During the study 30 patients out of 86 received a cementless femoral stem. The choice of stem fixation is determined by the quality of the bone. In all cases a 36 mm cobalt chromium head is used. Spherical tantalum markers, chosen because of the proven biocompatibility, were inserted into stable locations in the femoral bone during surgery using a specialized insertion tool, according to the protocol. Evaluation was done 1, 6, 12, 24, 52 weeks after surgery. Overall subsidence follows a parallel pattern for the cemented and uncemented prosthesis that is slightly stronger in for the uncemented prosthesis. Over the 6 months evaluation period the prosthesis migrates towards the lateral side with 0.25 mm in both groups. An anteroversion of 0.5° to 1° is noted at 6 months follow-up. The varus valgus movement of the prosthesis is similar for both groups at 6 months. At 6 weeks a slight valgus flexion is noted, this is reversed at 3 months. At this point in time the effect is more pronounced in the group with a cemented prosthesis. Micro motion is difficult to assess on plain radiography. In this study more subsidence is noted in the uncemented prosthesis compared to the cemented. The degree of rotation of the stem measured in our study is comparable with those reported by others. In our primary THR we observe a bi-modal micromotion except for the subsidence the initial movement up till 6 weeks is reversed at 3 months follow-up and at 6 months the prosthesis seems stabilized, though longer follow-up is required to confirm stabilization

Background: Measurement of quality of life (QOL) and functional status provides important additional information for priority setting in health policy formulation and resource allocation. Our aim was to define the differences in the health-related quality of life between hip artroplasties with cementation and without cementation. The last objective was to reunite evidences on the advantages and disadvantages of both systems of hip arthroplasty fixation. Methods: We analyzed a random sample of patients in surgical waiting list of total hip arthroplasty, between 65 and 75 years, divided in two groups of 40 patients who received a cemented or uncemented THA, respectively. We compared the pre-operative characteristics and at a year after operation changes in the Nottingham Health Profile (NHP) and SF-12 self-administered questionnaires. We also performed the specific Harris hip score. To make the different scoring systems comparable, all scores were transformed to a 0-to 100-point scale, with 100 points indicating best health. Differences among these groups were compared using the Mann-Whitney U test. Results: All patients increased their QOL scores. Both groups had similar QOL scores before surgery. At 1 year, patients with the uncemented prosthesis had slightly higher scores for energy, pain, and emotional reaction. Changes in QOL scores were, however, very similar. Conclusions: The use of an uncemented prosthesis does not impair early outcome

Introduction: We studied the survival of primary total hip arthroplasty (THA) in patients undergoing surgery because of rheumatoid arthritis (RA) and compared our results to the survival of primary THA in patients undergoing surgery because of osteoarthritis (OA). Furthermore, we evaluated the effect of primary THA-survival in RA-patients concerning multiple confounders such as age, gender, comorbidity, and cemented/uncemented prosthesis. Material and Methods: Using the Danish Hip Arthroplasty Register we gathered info concerning 1.302 primary THA’s in 1.106 RA-patients and 41.848 primary THA’s in 35.729 OA-patients. These patients underwent surgery from 1995 to 2004. Using the Cox regression model we estimated the relative risk (RR) for revision due to aseptic loosening, other reasons, and all reasons and adjusted for above mentioned confounders. Results: The adjusted RR’s for cup-revision of primary THA’s in patients with RA (compared to OA) were 1.22 (aseptic loosening − 95% Confidence Interval (CI) 0.75–1.99), 0.90 (other causes for revision − 95% CI 0.61–1.32), and 1.00 (all revisions − 95% CI 0.74–1.35). For the stem the RR’s were 0.50 (aseptic loosening − 95% CI 0.25–0.99), 0.58 (other causes for revision − 95% CI 0.35–0.95), and 0.54 (all revisions − 95% CI 0.36–0.80). RR for all revisions (both cup and stem) was 0.83 (95% CI 0.64–1.09). The RAsubanalysis showed an increased RR (all revisions) for men compared to women (RR 2.60; 95% CI 1.19–5.66). No significant result concerning all revisions for age, comorbidity, and cemented/ uncemented prosthesis was found. The mean follow-up was 5,4 years for RA and 4,8 years for OA. Conclusion: The survival of primary THA’s in RA could not be associated with any clearly overall increased risk of revision when compared to OA. However, male gender seems to be a risk factor for undergoing revision-THA in the RA-subgroup

Aims: Infection of total hip replacement still is considered a devastating complication. One stage revision, meaning removal of implant and debris together with insertion of a new prosthesis during the same operation, reduces rehabilitation time and costs. To overcome the disadvantages of using cement, uncemented techniques seem to be favourable. Methods: After removal of the implants debridement is performed as in conventional septic surgery. After thorough cleaning and rinsing, bone voids are filled with bone graft using an impaction technique. We use cancellous bone that is free from antigenic material but intact structures concerning collagen and mineral content. The bone is impregnated with high loads of antibiotic, using a proprietory incubation technique. There are two options of antibiotic impregnation: vancomycin or tobramycin. The impregnation procedure guarantees high levels of antibiotics at the grafting site for several weeks during which the antibiotic is released into the surrounding. Systemic drug levels usually are undetectable. Consequently an uncemented prosthesis is inserted. Wounds are drained and closed immediately, rehabilitation is performed as after non-septic surgery. Between 1996 and 2003 35 patients have been revised because of culture proven infection of a hip endoprostheses. All hips could be followed with a minimum of 3months and a maximum of 6years. Results: Wound healing was uneventful in all cases. Mean hospital stay was 16days (10–32days). In three hips there was recurrence of the infection, diagnosed between 6 and 12 weeks after surgery. One could be successfully re-operated using the same technique, the other two were converted to a girdlestone situation. All other 32 hips showed no sign of infection until the last follow up. Conclusion: One stage non-cemented revision may provide an excellent solution for infected total hip replacement. However, several principles need to be observed. Bone processed in an adequate way represents an excellent carrier for vancomycin and tobramycin. Using an antibiotic graft compound eradication of pathogens, grafting of defects and re-insertion of an uncemented prosthesis may be accomplished in a one stage procedure. Since the graft gradually is replaced by healthy own bone, improved conditions may be expected even in the case of another revision

Introduction. Titanium nitride (TiN) coatings are used in total hip arthroplasty to reduce friction of bearing couples or to decrease the allergic potential of orthopaedic alloys. Little is known about performance of currently manufactured implants, since only few retrieval studies were performed, furthermore they included a small number of implants manufactured over 15 years ago. Aim of study. To examine wear and degradation of retrieved TiN coated femoral heads articulating with ultra-high molecular weight polyethylene (UHMWPE). Methods. We included eight femoral heads with a made od TiAl6V4 alloy and coated with TiN using Physical Vapour Deposition (PVD). All heads (28 and 32 mm) were retrieved after at least 12 months of use (range 12–56). The reason for revision was aseptic loosening in 6 cases, septic loosening in one case and recurrent dislocations (five episodes) in one uncemented prosthesis. One unused head was included as reference sample. All implants were evaluated with light microscopy, Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDS). 30 SEM images from each implant were digitally analysed using ImageJ software to compare damage in loaded and non weight-bearing parts of the heads. Results. Studies with light microscopy revealed severe damage to the dislocated femoral head, with multiple metallic scratches. SEM studies indicated presence of multiple scratches and pinholes with a diameter of 1–10 µm (Fig1a,b,). Residue from the manufacturing process was present in all implants in form of pure Ti droplets found in round voids. In all implants we found irregular areas (diam. 20–50 µm, Fig 1c,d) where the coating was delaminated from the substrate metal with cracks arising from coating defects (Fig1e-h). Some of these debonded fragments were embedded into the PVD layer in weight-bearing parts of all heads. In one head, which was subjected to dislocations we observed deposits of titanium alloy from the acetabular shell (Fig 2a,b). The deposits were accompanied by large patches of delaminated coating as well as multiple cracks (Fig 2c,d). Small fragments of the acetabular titanium alloy damaged the coating in third body mechanism. Surprisingly in three implants we EDS analysis revealed similar spheres (diam. 1–10 µm) containing Niobium (Nb), although this element is not a part of any of the components used in the implants(Fig 2e,f). Interestingly presence of Nb droplets were associated with a higher number of other defect in these heads both in weight-baring and non weight-bearing parts of the heads suggesting inferior coating quality in these cases (Fig 2 g,h; Fig3, cases H2,H5,H8). Conclusions. Compared to previous studies we did not observe severe wear or the coating, however we observed some degradation of the film in vivo. Our results indicate that dislocation can lead to severe failure of the coating in vivo. Moreover presence of Nb residues and coexisting defects in some implants suggests inferior coating quality in these implants and indicates the need for strict monitoring of the production process. This study was funded by a grant from the National Science Centre nr 2012/05/D/NZ5/01840

Displaced fractures of the neck of femur are routinely treated in the elderly by either cemented hemiarthoplasty, in the fit, or uncemented hemiarthroplasty, in the less fit. In Scotland the Scottish Intercollegiate Guidelines Network (SIGN) guidelines are followed to identify which patients should have a cemented prosthesis. This is based on cardiovascular status, and the age and fragility of the patient. An uncemented prosthesis should be a final operation. A peri-prosthetic fracture is considered a failure of treatment as the patient then has to undergo an operation with a far greater surgical insult. We looked at all neck of femur fractures over a period of Jan 2007 to June 2010. The number of the peri-prosthetic fractures for uncemented hip hemiarthroplasties was established, and a case note review was carried out. There was 1397 neck of femur fractures. 546 hemiarthroplasties were carried out, of which 183 were cemented, and 363 uncemented. 15 patients (4% of uncemented hemiarthoplasties) had peri-prosthetic fractures. There were no peri-prosthetic fractures in the cemented group, p = 0.004 using Fisher's exact test. The case notes of these patients were analysed. We found there was a common link of significant cardiovascular risk, lack of falls assessment (only 14% of the patients had a completed falls assessment and 21% sustained their fracture during an admission to hospital) and confusion (50% had a degree of dementia that caused significant confusion). Cemented implants should be considered in all patients, especially those who are cognitively impaired or have failed falls assessments; even if the cardiovascular risk is significant. This decision should be made in conjunction with a senior anaesthetist. This is being implemented in our unit and a prospective audit is being carried out over the same time period (July 2010 to Dec 2013) to assess the benefit

Introduction. Cemented hemiarthroplasty for neck of femur fractures has been advocated over uncemented hemiarthroplasty due to better post-operative recovery and patient satisfaction. However, studies have shown adverse effects of bone cement on the cardio-respiratory system which may lead to higher morbidity and mortality. Therefore, in some institutes, the use of an uncemented prosthesis has been adopted for patients with a high number of co-morbidities. The aim was to compare early mortality rates for cemented vs. uncemented hemiarthroplasties. Method. Cohort study of displaced intracapsular hip fractures treated with hemiarthroplasty between 1999–2009 at one institute. A total of 3094 hemiarthroplasties performed; out of which 1002(32.4%) were cemented and 2092(67.6%) were uncemented. 48hour and 30day mortality rates for the two groups were compared and a multivariate Cox regression model used to eliminate confounding factors. Significant confounding factor included age, sex, mini mental test score, medical co-morbidities, Nottingham Hip Fracture Score and delay to surgery. Results. The study showed that, after eliminating confounding factors, 48hour mortality in the cemented group was 0.3% compared to 0.5% in the uncemented group (p=0.388). However, the adjusted 30day mortality rate for the cemented group (4%) was shown to be significantly lower than for the uncemented group (10.8%) (p< 0.001). Conclusion. The use of cement in hip hemiarthroplasty is not associated with an increased rate of mortality at 48hours or at 30days. Along with emerging evidence of better post-op recovery and patient satisfaction with the use of a cemented prosthesis, we support the use of cement for all patients undergoing hip hemiarthroplasty

Displaced fractures of the neck of femur are routinely treated in the elderly by either cemented hemiarthoplasty, in the fit, or uncemented hemiarthroplasty, in the less fit. In Scotland the Scottish Intercollegiate Guidelines Network (SIGN) guidelines are followed to identify which patients should have a cemented prosthesis. This is based on cardiovascular status, and the age and fragility of the patient. An uncemented prosthesis should be a final operation. A peri-prosthetic fracture is considered a failure of treatment as the patient then has to undergo an operation with a far greater surgical insult. We looked at all neck of femur fractures over a period of Jan 2007 to June 2010. The number of the peri-prosthetic fractures for uncemented hip hemiarthroplasties was established and a case note review was carried out. There was 1397 neck of femur fractures. 546 hemiarthroplasties were carried out, of which 183 were cemented, and 363 uncemented. 14 patients (4% of uncemented hemiarthoplasties) had peri-prosthetic fractures. The case notes of these patients were analysed. We found there was a common link of significant cardiovascular risk, lack of falls assessment (only 14% of patients had a completed falls assessment and 35% sustained their fracture during an admission to hospital) and confusion (43% had a degree of dementia that caused significant confusion). Cemented implants should be considered in those who have failed falls assessment, or are confused; even if the cardiovascular risk is significant. This decision should be made in conjunction with a senior anaesthetist. This is being implemented in our unit and a prospective audit is being carried out over the same time period (July 2010 to Dec 2013) to assess the benefit

Purpose of study:. The purpose of the study is to evaluate the changes in peri-prosthetic bone mineral density following cemented and cementless total hip arthroplasty over a follow up period of 1 year. Description of methods:. Ethics approval was sought and granted by the South African Medical Association Research Ethics Committee (SAMAREC). Patient consent for participation was obtained. Recruitment of the cohort took place over 2 years. Patients received an uncemented (Synergy) or cemented (Spectron) prosthesis as clinically appropriate. Functional status according to the University of California Los Angeles activity scale (UCLA scale) and bone mineral density as measured by Dual Energy X-ray Absorptiometry (DEXA) was assessed pre-operatively and at 3 months, 6 months and 12 months post-operatively. An independent Contract Research Organisation was used to monitor the site. Summary of results:. As at August 2010, 59 unique patients had undergone 59 hip replacements, and 7 patients (8.5%) were still due their 12 month evaluation. The mean UCLA scored showed a marked and steady improvement post-operatively, with most of the gain demonstrated by 3 months. When evaluating all patients, the mean pre-operative values for Gruen Zones 2, 4, and Net were significantly lower than the mean 12 month values. When evaluating patients who received the uncemented prosthesis (n=40), the mean pre-operative values for Gruen Zones 2 and Net were significantly lower than the mean 12 month values, and the mean pre-operative values for Gruen Zones 1 and 3 were significantly higher than the mean 12 month values. When evaluating patients who received the cemented prosthesis (n=19), the median pre-operative values for Gruen Zones 1, 2, 3, 4, 7 and Net were significantly lower than the median 12 month values. Conclusion:. At 1 year post surgery overall bone density showed a significant increase in both the cemented and uncemented cohort

The ABG total hip prosthesis had been studied to prevent any kind of stress shielding and to allow the localization of the loads in the metaphiseal region of the femur. The aim of this study was to analize the effective behaviour of the loads in long-term implants and the possible correlations of those findings with the clinical situation of the patients. We considered 87 total hip arthroplasty implants executed from 1989 to 1995 and performed by using Anatomique Benoist Girard I uncemented prosthesis. The radiographical findings have been classified observing Engh’s stability criteria according to Gruen’s subdivision of the periprosthetic femoral zones. The radiographical analysis shows a higher presence of can cellous densification in Gruen’s zones 3 and 5 than the one found in zones 2 and 6. Furthermore the presence of a cortical reaction is more relevant in the distal zones.> Radiolucent lines are present in 16% of the cases in zone 4; their percentage in zones 3 and 5 decreases to 7.14% and 10.71%. Our study shows the certain presence of the stress shielding mechanism in long-term analysis and documents that the main region of late anchorage is the distal, not hydroxyapatite-coated, one.> The comparison with other similar studies shows the decrease of the presence of radiolucent lines in proximal femoral zones with the rise of the follow-up: it can be interpreted as the lesser presence of micro movements of the tip of the prosthesis due to the distalization of the anchorage

Introduction: The distorted anatomy in Developmental Dysplasia of the Hip (DDH) makes a total hip arthroplasty (THA) a challenging procedure. The purpose of the current study is to report the midterm results after uncemented primary hip arthroplasty using S ROM prosthesis in a prospective series of patients with hip dysplasia. Methods: We performed 22 uncemented total hip replacements using S ROM prosthesis in 21 (12 female and 9 male) patients with hip dysplasia. The means age at the time of hip surgery was 41.8 (22 to 64) years. The mean follow-up was 6.3 (3.8 to 9.6) years. In 9 (40.9%) patients the operative treatment of DDH was performed during the early childhood (femoral osteotomy in 6 and pelvic osteotomy in 3). All patients were evaluated clinically and radiologically. The femoral head displacement prior to THA surgery was classified according to Crowe at al. classification (4 hips were type1, 2 type2, 10 type3 and 6 type 4). Results: The average Harris Hip Score improved from 29.48 to 72.76 (44 to 99) and the average Oxford hip score is 31.22 (12 to 47). The range of flexion is 60°–120° (average 83.23) and abduction is 10°–40°(average 22.94). None of the hips has dislocated. Radiolucent lines were noted around the femoral stem in one case. None of the cases have developed osteolysis around femoral prosthesis. In one patient (4.5%), revision hip surgery was done for aseptic loosening of cemented acetabular cup. Discussion: The midterm results of total hip replacement in DDH using S ROM uncemented prosthesis are promising. We recommend this modular prosthesis for hip replacement in dysplastic hips

Background: Infection remains the single most devastating complication of joint arthroplasty. In cases of established prosthetic infection, where implant retention is not feasible, there is limited consensus on an optimum management protocol. Aim: To assess the outcome of revision for infected hip prostheses using a novel treatment regimen. Materials and Methods: Retrospective study of a consecutive case series of 40 patients with late chronic hip joint prosthetic infection treated by a single surgeon over a 4 year period. The mean interval between index arthroplasty and revision for infection was 40 months, with patients having prior symptoms of infection for a mean of 22 months. The treatment protocol consisted of a two stage exchange with removal of infected components via a posterior approach incorporating an extended trochanteric osteotomy, insertion of an interim antibiotic eluting cement spacer and re-implantation of an extensively coated uncemented prosthesis on the femoral side. Systemic antibiotic treatment following each stage consisted of an abridged course of 5 days post operative intravenous administration followed by complete cessation of anti-microbial therapy. The mean interval between implant removal and re-implantation was 111 days. Results: At a mean follow up of 29.6 months (minimum 12 months), there were 2 cases of recurrent prosthetic infection. Dislocation following the second stage occurred in 7 patients. There was one mortality and one case of post operative sciatic nerve palsy. The Harris hip score increased from a pre-operative mean of 43.8 to a post operative mean of 83.9. At follow up, no patient had required revision for aseptic loosening or mechanical instability on the femoral side. Conclusion: The combination of effective staged surgical joint debridement, a shortened post operative course of systemic antibiotic treatment and an adequate latent period before re-implantation has led to encouraging early results in this series of revised chronic hip joint prosthetic infections

Aims: To derive a formula for blood loss estimation and also to assess if high body weight is protective against blood transfusion following elective arthroplasty? Methods: Retrospective study of patients undergoing elective primary hip arthroplasty. Weight of the patient, pre and postoperative haematological investigations and details of blood transfusion were collected. Results: Formula for blood loss estimation was derived, Blood loss= ( 70 x body weight in Kg) x (drop in haematocrit) (Pre-op haematocrit+ post-op haematocrit)Ö2. The mean blood loss in 86 patients was 1631ml. Mean blood lost/Kg body weight was 22.6ml. 36/86 patients had < 21ml/kg (42%) and 50/86 had > 21ml/kg blood loss (58%). 21 ml/kg represents 30% loss of blood volume. Patients losing > 21ml/kg blood had signiþcantly higher blood transfusion rates (Chi squared test; χ2(1)= 5.50, p=0.02). The amount of blood loss increases with weight of patients (p< 0.01). The rates of transfusion in patients with ≤ 72 kg weight (circulatory volume ~ 5 litre) was 51% (23/45), and in patients > 72 kg it was 36.5% (15/41). Rates of transfusion were related to pre-op Hb but were unaffected by gender, age, cemented/uncemented prosthesis, surgical approach, type of prosthesis, use of drains, grade of surgeon, type of anaesthetic. Conclusion: Calculated blood loss > 21ml/kg and patientñs low body weight are associated with increased risk of blood transfusion

Aim: To evaluate the medium term results of revision hip replacements using the ‘Furlong’(© JRI, London) HAC covered total hip replacement system. Methods: The first one hundred revision hip replacements were identified from the arthroplasty register of the senior author. The notes and x-rays at presentation were retrospectively analysed to ascertain the clinical and radiological state pre-operatively. The surgical findings were also noted. The final clinical and radiological states were obtained from the latest outpatient appointment. Modified Harris Hip Score was used to discern the clinical state. SPSS © vol 11.0 was used for statistical analysis. Results: There were one hundred revision hip replacements performed in 97 patients between 1991 and 2000 by the senior author. There were 72 cemented and 18 uncemented prosthesis revised. 9 of the revisions were for infection. 79 were revised for aseptic loosening of one or both of the components. There were 4 recurrent dislocators and one revision was carried out for a peri-prosthetic fracture. The median to follow up was 3 years (mean 3.8, range 1–8).The changes in the clinical state of the patient at the last follow up are shown in the table: At the time of the latest follow-up 74 of the cups and 69 of the stems showed definite radiological signs of osseointegration. Discussion: Our results show that clinical results of revision surgery using this system give good results in the short to medium term. Radiological results are less easy to interpret as osseointegration can take a long time to become visible on x-rays. The need for longer term follow-up is highlighted by the results

Introduction and Aims: Little is known about peri-acetabular bone remodelling after insertion of the acetabular cup in total hip arthroplasty. This study was designed to analyse retroacetabular bone changes using quantitative CT-assisted osteodensitometry. This is a new method for a detailed measurement of bone density (BD) changes around the implants. Method: Prospective cohort study. Operations were performed on 26 consecutive hips (26 patients) using an uncemented prosthesis with alumina-alumina pairing (Cerafit, Ceraver Osteal, France). The average age of patients was 58.4 years. There were 15 men and 11 women. CT investigations were performed within two weeks of surgery and then one year and three years post-operatively. Cancellous, cortical and total bone density (mgCaHA/ml) were assessed using specific software (Impact-Hip, VAMP, Moehrendorf, Germany). Results: All 26 hips were available for follow-up at one year, seven patients were available at three years. At three-year follow-up we found an 18.4% decrease of cancellous BD proximal to the upper rim of the cup. Cortical BD increased by + 5.2% in this region. Cortical BD decreased ventral to the cup by −5.0% and by −2.3% dorsal to the cup. Of more interest, cancellous BD was observed to decrease by −40.9% in the ventral region and −32.2% in the dorsal region. Conclusion: We have observed a progressive decrease of cancellous BD after insertion of an uncemented ace-tabular component. These phenomenon could explain the onset of late migration and implant failure of pressfit cups. Only minor changes have been observed in cortical BD. Further investigations are required to define the role of implant design and material in periprosthetic bone remodelling of the acetabulum