Introduction. The ideal method of fixation for femoral components in total hip arthroplasty (THA) is unknown. While good results have been reported for cemented and uncemented components, there is relatively little published prospective data with twenty years or more of follow up. Results of the Furlong femoral component have been presented at an average of 17 years follow up. We have extended this follow up period to an average of 22.5 years with a minimum of 22 years and a maximum of 25 years. Methods. This study included all patients treated using the Furlong femoral component between 1986 and 1991. Patients were reviewed preoperatively and then at 6, 12, 26 and 52 weeks post operatively and annually thereafter. They were assessed clinically and radiographically and the Merle d'Aubigne Postel hip score was calculated at each visit. A Visual Analog Score (VAS) was also recorded to assess patient satisfaction with their procedure. A Kaplan Meier survival analysis was performed. Results. Sixty patients (72 hips) were included (15 males, 45 females). Bilateral procedures were performed in 12 patients. Mean age was 82.9 years (70 to 100 years). Mean follow-up was 22.5 years (20 to 25). The Merle d'Aubigne Postel hip score at final follow up was 5.5 (pain), 3.8 (mobility) and 3.3 (function) for function. Seven patients required revision surgery. Survival of the femoral component with revision for any reason as the end point was 90.3%. There were no planned revisions up to the time of final follow up. Conclusion. The Furlong prosthesis results in improvement of pain in the long term. Survival of this component is comparable to the best results for primary THA with any means of fixation

The optimum design for the femoral component for cementless Total Hip Replacement is not known. We conducted an ethically approved, randomised and prospective trial to compare two radically different designs of fully hydroxyapatite (HA) coated femoral stems. We compared the original JRI Furlong stem with the Wright Anca fit stem which is more anatomical in design. The paper discusses the merits and disadvantages of these two stems. The same acetabular component was used in both samples. The only variable was the stem shape. All patients placed on the senior author's waiting list for primary THR were asked if they would enter the trial. There were no restrictions for selection to the sample. Patients were then randomised for one of the two stems. All surgery was performed by or under the direct supervision of the senior author. The periprosthetic and perioperative fracture rates for the two stems were found to be significantly different at three years into the study and the trial was stopped. 337 patients had been entered into the trial, 211 females and 126 males. 191 patients had the JRI furlong hip implanted (57%) and 146 are in the Anca sample (43%). The number of perioperative fractures in the Furlong group was 13 (6.8%)and in the Anca sample 22 (15.1%). This is statistically significant. The possible reasons for this difference are discussed. Anatomical fit cementless stems require a more careful technique to avoid fracture during implantation and the shorter stemmed Anca hip proved less stable in the presence of a fracture necessitating further surgical intervention. It is still not certain whether the anatomical shape has long term advantages that may outweigh this initial disadvantage and the cohort of patients continues to be followed up

Introduction. Hydroxyapatite (HA) coated femoral stems require a press fit for initial stability prior to osteointegration occurring. However this technique can lead to perioperative femoral fracture. Materials and Methods. 506 consecutive patients under 72 years who underwent primary total hip replacements (THR) under 72 years were investigated for perioperative femoral fractures. All patients were independently assessed pre- and post-operatively in a research clinic. Assessment was made by Merle d'Aubigné and Postel (MDP) hip scores and radiographs. Between 1995 and 2001 patients were randomised to a partially HA coated, Osteonics Omnifit or fully HA coated Joint Replacement Instrumentation Furlong stem. Between 2001 and 2004 all patients received an Anatomique Benoist Girard (ABG II) stem partially coated. Fractures were identified from check radiographs and operative notes. The type of fracture was classified according to the modified Vancouver classification. The incidence of revision was also recorded. Results. There were 38 fractures (7.5%) overall. The Omnifit group had 9 fractures (7.4%) the Furlong 11 (8.9%) and the ABG II 18 (6.7%). Twenty-four cases were treated by internal fixation at the time of primary surgery. Four cases had an unsatisfactory result and two were revised. Fourteen had conservative treatment. Seven of these had an unsatisfactory result and four required early revision. The difference between the operated and conservative treatment groups was significant (P<0.01). There was a correlation between Vancouver classification and outcome. Conclusion. Perioperative fracture is relatively common. The type of fracture has an influence on the outcome. Unstable fracture patterns require internal fixation at the time of initial surgery

Cemented Total Hip Arthroplasty gives good results for 10 or more years, but is too often complicated by a combination of mechanical loosening, wear debris and osteolysis. Patients require an implant which will last the rest of their life. Cemented hips may not survive and a better alternative is needed. Furlong hydroxyapatite ceramic coated (HAC) implants have been used for more than 19 years and to date there are 2248 primary hip arthroplasties. Fixation of the implants with HA ceramic is entirely satisfactory; histological studies from post-mortem specimens have confirmed that there is good cancellous bone fixation to the HA. The hydroxyapatite behaves like bone and is replaced by creeping substitution. This results in a Perfect Fit with no intervening fibrous tissue. Fixation is therefore maintained. Aseptic loosening is rare; eleven components. Polythene wear is a problem. Those patients with ceramic/polythene couples who have now reached about 15 years since surgery are showing wear of the liner evidenced by eccentricity of the ceramic head in the liner. Three of these have completely destroyed the liner and the titanium shell. Ceramic/ceramic bearings do not seem to wear, although there have been occasional fractures of alumina. For the last two years Biolox Delta, a stronger compound ceramic material, has been available from Ceramtec. There are no reports of any fractures. Patients who have a life expectancy of more than 10 or 15 years should be fitted with an HA coated implant with ceramic bearing surfaces. This may provide the answer for the long-lasting hip prosthesis

We aim to report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong HAC coated femoral and acetabular components. We reviewed 586 consecutive cementless primary THA in 542 patients with a minimum 12-18 year follow-up, performed at one institution between 1986 and 1994. Twenty-eight (32 THA) were lost to follow-up. Clinical outcome was measured using Harris, Charnley and Oxford scores. Quality of life using EuroQol. EQ-5D. Radiographs were systematically analysed. The mean age was 75.2 years. Dislocation occurred in 12 patients (three recurrent). Re operations were performed in 11 patients (1.9%). Four acetabular and one stem revisions were performed for aseptic loosening. Other re-operations were for infection (two), periprosthetic fractures (two), cup malposition (one), revision of worn liner (two). The mean Harris and Oxford scores were 89 (79–96) and 18.4 (12–32) respectively. The Charnley score was 5.7 for pain, 5.3 for movement and 5.4 for mobility. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06 mm/year. Stable stem by bony ingrowth was identified in all hips excluding one femoral revision case. Mean stem subsidence was 2.2mm (0.30–3.4mm). Radiolucencies were present around 37 (6.6%) stems. EQ- 5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, survival at 12 years was 96.1% for acetabular and 98.3% for femoral components. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 97.2%. The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long-term period

Introduction. We aim to report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong HAC coated femoral and acetabular components. Methods. We reviewed 586 consecutive cementless primary THA in 542 patients, with a minimum 12-year follow-up to 18 years, performed at one institution between 1986 and 1994. Twenty eight (32 THA) were lost to follow-up. Clinical outcome was measured using Harris, Charnley and Oxford scores. Quality of life using EuroQol EQ-5D. Radiographs were systematically analysed. Results. The mean age was 75.2 yrs. Dislocation occurred in 12 patients (3 recurrent). Re-operations were performed in 11 patients (1.9%). Four acetabular and one stem revisions were performed for aseptic loosening. Other re-operations were for infection (2), periprosthetic fractures (2), cup malposition (1), revision of worn liner (2). The mean Harris and Oxford scores were 89 (79- 96) and 18.4 (12-32) respectively. The Charnley score was 5.7 for pain, 5.3 for movement and 5.4 for mobility. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Stable stem by bony ingrowth was identified in all hips excluding one femoral revision case. Mean stem subsidence was 2.2mm (0.30- 3.4mm). Radiolucencies were present around 37 (6.6%) stems. EQ-5D description scores and health thermometer scores were 0.81 (0.71-0.89) and 86 (64-95). With an end point of definite or probable loosening, survival at 12 years was 96.1% for acetabular and 98.3% for femoral components. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 97.2%. Conclusion. The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long term period

We report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic (HAC) coated acetabular components. We reviewed 412 consecutive cementless primary THA using fully coated acetabular shell in 392 patients—with a minimum 12 to 18 year follow-up—performed at two institutions between 1986 and 1994. Twenty (22 THA) were lost prior to 12-year follow-up, leaving 372 patients (390 THA) available for study. Fully HAC coated stems were used in all patients. The clinical outcome was measured using Harris, Charnley and Oxford hip scores and the quality of life using EuroQol EQ-5D. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Polythene wear was digitally measured. The radiographic stability of the acetabular component was determined by Enghs criteria. The mean age was 74.4 years. The mean Harris and Oxford scores were 87 (78– 97) and 19.1 (12–33) respectively. The Charnley score was 5.6 (5-6) for pain, 5.2 (4–6) for movement and 5.3 (4–6) for mobility. Migration of acetabular component was seen in four hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Mean inclination was 48.4° (38–65). Radiolucencies were present around 37 (6.6%) stems. Dislocation occurred in 10 patients (three recurrent). Re-operations were performed in nine patients (1.9%). Four acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (three), periprosthetic fractures (one), cup malposition (one) and revision of worn liner (three). Mean EQ-5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 97.1% for acetabular component. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 96.2%. The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long-term period

INTRODUCTION. Ceramic-on-ceramic hip replacements have generated great interest in recent years due to substantial improvements in manufacturing techniques and material properties. 1. Microseparation conditions that could occur due to several clinical factors such as head offset deficiency, medialised cup combined with laxity of soft tissue resulting in a translation malalignment, have been shown to cause edge loading, replicate clinically relevant wear mechanisms. 2,3. and increase the wear of ceramic-on-ceramic bearings. 3,4. The aim of this study was to investigate the influence of increasing the femoral head size on the wear of ceramic-on-ceramic bearings under several clinically relevant simulator conditions. MATERIALS AND METHODS. The wear of size 28mm and 36mm ceramic-on-ceramic bearings (BIOLOX® Delta, CeramTec, Germany) was determined under different in vitro conditions using the Leeds II hip simulator. For each size bearing, two clinical cup inclination angles were considered, 55° (n=3) and 65° (n=3) for the 28mm bearing and 45° (n=3) and 65° (n=3) for the 36mm bearing. The first two (28mm study) or three (36mm study) million cycles ran under standard gait conditions and a subsequent three million cycles ran under microseparation conditions. A standard gait cycle included a twin peak load (300N–3000N), extension/flexion (−15°/+30°) and internal/external rotation (±10°). Microseparation. 3. was achieved by applying a 0.4–0.5mm medial displacement to the cup relative to the head during the swing phase of the standard gait cycle resulting in edge loading at heel strike. The lubricant was 25% (v/v) new-born calf serum which was changed approximately every 333,000 cycles. The wear volume was ascertained through gravimetric analysis every million cycles. One way ANOVA was performed (significance: p<0.05), and 95% confidence limits were calculated. RESULTS AND DISCUSSION. The mean wear rate under standard gait conditions was 0.05mm. 3. / million cycles for the 28mm bearings and significantly lower (p=0.003) for the 36mm bearings (Figure 1) which could be due to improved lubrication regime. The wear of ceramic-on-ceramic bearings was not influenced by the increase in cup inclination angle for either bearing size (Figure 1). The introduction of microseparation into the gait cycle resulted in stripe wear on the femoral head with a corresponding wear area at the rim of the acetabular cup and significantly higher wear rates of the ceramic-on-ceramic bearings (Figure 2). The wear rate of BIOLOX® Delta bearings under microseparation conditions was still low (<0.25mm. 3. /million cycles) compared to the third generation alumina ceramic-on-ceramic bearings (1.84mm. 3. /million cycles). 4. under the same adverse conditions. Under microseparation conditions, the wear rate of size 36mm bearings was significantly higher (p=0.004) than that for size 28mm bearings. This was thought to be due to the larger contact area for the larger bearings and deprived lubrication under edge loading conditions. For both bearing sizes, the combination of both steep cup inclination angles and microseparation conditions did not increase the wear rates any further compared to microseparation conditions alone (Figure 3). This study shows the importance of surgical positioning of the femoral head and acetabular cup and the importance of testing new bearing materials and designs using these adverse simulator methods. ACKNOWLEDGEMENT. This study was supported by the Furlong Research Charitable Foundation (FRCF) and the National Institute of Health Research (NIHR) as part of a collaboration with the Leeds Musculoskeletal Biomedical Research Unit (LMBRU)

INTRODUCTION. Retrieval and clinical studies of metal-on-metal (MoM) bearings have associated increased wear. 1. and elevated patient ion levels. 2. with steep cup inclination angles and edge loading conditions. The University of Leeds have previously developed a hip simulator method that has been validated against retrievals and shown to replicate clinically relevant wear rates and wear mechanisms. 3,4. This method involves introducing lateral microseparation to represent adverse joint laxity and offset deficiency. This study aimed to investigate the effect of microseparation representing translational malpostion, and increased cup inclination angle, representing rotational malposition, in isolation and combined on the wear of different sizes (28 and 36mm) MoM bearing in total hip replacement (THRs). MATERIALS AND METHODS. The wear of size 28mm and 36mm MoM THRs bearings was determined under different in vitro conditions using the Leeds II hip simulator. For each size bearing, two clinical cup inclination angles were considered, 45° (n=3) and 65° (n=3). The first three million cycles were run under standard gait conditions and subsequently three million cycles were run under microseparation conditions. Standard gait cycles included a twin peak load (300N–3000N), extension/flexion (−15°/+30°) and internal/external rotation (±10°). Microseparation. 4. was achieved by applying a 0.4–0.5mm medial displacement to the cup relative to the head during the swing phase of the standard gait cycle resulting in edge loading at heel strike. The lubricant was 25% (v/v) new-born calf serum. The wear volume was determined through gravimetric analysis every million cycles. One way ANOVA was performed (significance: p<0.05), and 95% confidence limits were calculated. RESULTS. Under standard gait conditions, the 28mm MoM bearing showed head-rim contact and increased wear rate with increased cup inclination angle but the 36mm bearing did not show any increase in wear. Microseparation and edge loading increased the wear rate of MoM bearings for all cup inclination angle conditions and bearing sizes (Figure 1). DISCUSSION. With the larger size bearings, head-rim contact occurred at a steeper cup inclination angle (>65°) providing an advantage over smaller bearings. Under standard gait conditions, where head-rim contact did not occur, wear was low, due to mixed lubrication and wear reduction through a protein boundary film. However, edge loading of the cup, with elevated stress, caused excess damage and wear. This effect was more dominant with microseparation conditions to that of head-rim contact due to increased cup inclination angle alone. Under microseparation conditions, there were no significant differences in the wear rates of the 28mm and the 36mm size bearings. However, the wear rates obtained in this study for 28mm and 36mm bearings were significantly lower than those obtained for size 39mm surface replacement MoM bearings (8.99 mm. 3. /million cycles) tested under the same adverse conditions. 5. . CONCLUSION. This study shows the importance of acetabular cup design and correct surgical positioning of the femoral head and acetabular cup and restoration of offset and cup centre. ACKNOWLEDGEMENT. This study was supported by the Furlong Research Charitable Foundation (FRCF) and the National Institute of Health Research (NIHR) as part of a collaboration with the Leeds Musculoskeletal Biomedical Research Unit (LMBRU). The components were custom made specifically for this project by Corin Ltd