Sir John Charnley unquestionably was the pioneer of modern joint arthroplasty. He was also an innovator in many other areas of orthopedics, including fracture care and arthrodesis, but this tribute will focus on his contributions to arthroplasty. Charnley pioneered the use of methyl methacrylate cement and in so doing provided the first reliable means of fixing implants to bone. For the first time, this provided arthritis patients with reproducible long-term, reliable pain relief from advanced joint arthritis. Charnley also pioneered the use of a novel bearing surface, high molecular weight polyethylene. In so doing, he pioneered resurfacing of both sides of a joint with a low-friction, low-wear bearing. This provided the potential for excellent pain relief and also durable function of a hip arthroplasty. Charnley understood the importance of reproducing joint mechanics and kinematics, and the arthroplasties he designed fully reproduced leg length and hip offset, and therefore the mechanics of the hip. Finally, Charnley understood that technology is only a great value when it can be transferred effectively to many surgeons around the world. He created a carefully constructed educational structure to teaching the methodology in a way that would allow surgeons to practice this procedure successfully in other centers. Charnley understood the importance of minimizing complications for a procedure to be widely adopted and successful. It is no exaggeration to state that Charnley’s contributions have helped tens of millions of patients worldwide who otherwise would have been permanently crippled by arthritis. Today’s further advances in joint arthroplasty are all dependent on the foundations of joint arthroplasty pioneered by Sir John Charnley

To evaluate the effects of 6 and 18 months of abaloparatide (ABL) compared with placebo (PBO) on bone mineral density (BMD) in the acetabular regions of postmenopausal women with osteoporosis (OP). Acetabular bone loss, as may occur in OP, increases risk of acetabular fragility fractures. a. In total hip arthroplasty (THA), low acetabular BMD adversely affects primary stability, osseointegration, and migration of acetabular cups. c. ABL is an osteoanabolic agent for the treatment of men and postmenopausal women with OP at high risk for fracture. Effects of ABL on acetabular BMD are unknown. Hip DXA scans were obtained at baseline, 6, and 18 months from a random subgroup of postmenopausal women (aged 49–86 y) from the phase 3 ACTIVE trial randomized to either ABL 80 µg/d or PBO (n=250/group). Anatomical landmarks were identified in each DXA scan to virtually place a hemispherical shell model of an acetabular cup and define regions of interest corresponding to DeLee & Charnley zones 1 (R1), 2 (R2), and 3 (R3). BMD changes compared to baseline were calculated for each zone. Statistical P values were based on a repeated mixed measures model. BMD in all zones were similar at baseline in the ABL and PBO groups. BMD significantly increased in the ABL group at 6 and 18 months compared with PBO (all P<0.0001 vs PBO). BMD in the PBO group was relatively stable over time. ABL treatment resulted in rapid and progressive increases in BMD of all 3 acetabular zones. Increasing acetabular BMD has the potential to improve acetabular strength, which may reduce risk of acetabular fragility fractures. In bone health optimization prior to THA, increased acetabular BMD via ABL may provide better primary stability and longevity of acetabular cups in postmenopausal women with OP

We report the results of the Charnley Elite Plus femoral stem (Ortron 90; Depuy, Leeds, United Kingdom) in multiple surgeon’s hands at a minimum of three years post implantation. The long term results of the Charnley femoral stem have been widely documented . There have been numerous changes to the design and instrumentation of this original stem since its introduction in 1962, and the Charnley Elite Plus represents the fifth generation of this highly successful implant. Between March 1994 and March 1998, 244 patients underwent 268 primary hip arthroplasty procedures using this particular stem. Patients were reviewed at a mean of 4.5 years (3.0 – 6.8 years) following their arthroplasty using the Oxford Hip Score and plain radiographs. There were five revision procedures for aseptic loosening (5/268; 1.9%). Radiological assessment revealed gross radiological failure in a further 12 femoral stems (12/208; 5.8%). There was evidence of focal osteolysis with an apparently stable implant in 36 hips (17.3%). In the best case scenario, using revision for aseptic loosening as the endpoint, the survivorship for this period is 98.1%. If radiographic failures are incorporated into this endpoint, survivorship is 93.1%. Of potential concern however, is the number of adverse features noted on the radiographs, with only 76.9% being categorised as ‘normal.’. The Charnley Elite Plus stem has undergone some fundamental design changes from the original Charnley stem and therefore clinical success should not be automatically assumed. In such circumstances we recommend regular clinical and radiographic follow-up of patients who have have undergone total hip arthroplasty with this particular femoral stem

The Charnley Elite femoral component was first introduced in 1992 as a new design variant of the original Charnley femoral component (De Puy, Leeds, UK) with modified neck and stem geometry. The original component had undergone few changes in nearly forty years and has excellent long-term results. Early migration of the new stem design was determined by Roentgen Stereophotogrammetric Analysis (RSA)1. Rapid early migration of a component relative to the bone, measured by RSA, is predictive of subsequent aseptic loosening for a number of femoral stems. As there was rapid early migration and rotation of the Charnley Elite stem, we predicted that the long-term results would be poor. An outcome assessment is indicated as stems of this type are still being implanted. One hundred Charnley Elite stems, implanted in our centre between 1994 and 1997 were included in a prospective, cross-sectional follow-up study. Outcome measures include validated clinical scores (Charnley hip score, Harris hip score and Oxford hip score) and radiological scores (Gruen classification) as well as revision rates over the past 10 years. The clinical follow-up supports the RSA predictions of early failure of the Charnley Elite femoral stem

Introduction: The Charnley Elite femoral component was first introduced in 1992 as a new design variant of the original Charnley femoral component (De Puy, Leeds, UK) with modified neck and stem geometry. The original component had undergone few changes in nearly forty years and has excellent long-term results. Early migration of the new stem design was determined by Roentgen Stereophotogrammetric Analysis (RSA). Rapid early migration of a component relative to the bone, measured by RSA, is predictive of subsequent aseptic loosening for a number of femoral stems. As there was rapid early migration and rotation of the Charnley Elite stem, we predicted that the long-term results would be poor. An outcome assessment is required as stems of this type are still being implanted. Materials and method: One hundred Charnley Elite stems, implanted in our centre between 1994 and 1997 were included in a prospective, cross-sectional follow-up study. Outcome measures include validated clinical scores (Charnley hip score, Harris hip score and Oxford hip score) and radiological scores (Gruen classification) as well as revision rates over the past 10 years. Results: The preliminary analysis results are given. The mean time to follow-up was 8.28 years. 20 patients have died due to causes unrelated to their operations. 10 patients had stem revisions: 9 for aseptic loosening and 1 for a peri-prosthetic fracture. This indicates a significant 10% failure rate of the prosthesis in less than 10 years. Preliminary clinical scores in the patients who had not undergone any subsequent surgery were adequate (Oxford Hip Score mean average of 23.9). Thirteen percent of radiographs analysed had evidence of loosening, giving an overall loosening rate of 14% at 8 years. Discussion and conclusion: The clinical follow-up supports the RSA predictions of early failure of the Charnley Elite femoral stem

Introduction/objective: The results of Charnley total hip replacement, when performed in the general setting, may not be as good as expected (. 1. ). The objective is to know the long time survival in a Charnley low friction arthroplasty series performed in a General Hospital. Material and methods: To have a minimum follow-up of ten years, we analysed 404 cases from a 431 series implanted in our department between 1976 and 1993. Mean age was 67 years, 57% were women. The survival was calculated used Kaplan-Meier method, considering revision surgery as the analyzed event. Age and gender relation with survival were analyzed using the Log-Rank test. Results: The survival of the Charnley low friction arthroplasty with the 95 % confidence interval was 92% (95–89%), 87% (90–81%), and 83% (89–78%) at 10, 15, and 20 years respectively. Patients younger than 60 years in the surgery time had lower survival than the older group for the acetabular (Log-Rank test p=0.043) and femoral components (Log-Rank test p=0,0085). There is not a statistically significant difference related to gender. Conclusions: The survival in our low friction arthroplasties series at 10, 15, and 20 years is similar to the found in multicentric studies performed in other centres with special dedication to the surgery of the hip (. 2. ). Age affected the likelihood of long-term survivorship of the acetabular and femoral components used in Charnley low friction Arthroplasty

Introduction and Aims: This is a prospective randomised trial comparing the ABG uncemented total hip replacement with the Charnley in 243 patients less than 65 years of age. A standardised protocol and anterolateral approach was used. Method: The ABG I cup was used in combination with a polyethylene liner. All stems were templated and a 28mm cobalt chrome head was used. Early mobilisation with partial weightbearing for six weeks was allowed. In the Charnley group, Elite polyethylene cups were used in conjunction with 22mm monoblock stems. All hips were inserted with pressurised CMW cement. Patients were followed up annually. Standardised radiographs were taken at each visit and the Harris hip score and Merle d’Aubigné outcome measures recorded. There were 222 hips available for follow-up, 96 ABG hips and 126 Charnley hips (17 died and 10 were lost to follow-up), with the mean age at surgery and mean length of follow-up comparable. Most hips were replaced due to osteoarthritis. There was no significant difference in the mean Harris hip or Merle d’Aubigné scores at one year and at latest follow-up. Results: Radiographic results demonstrated accelerated polyethylene wear in the ABG hips with mean polyethylene wear at seven years being 2.1mm compared with 0.9mm for Charnley hips. Wear associated lysis around the ABG cup was the major reason for failure, with a total of eight cups (8.3%) undergoing revision. Conclusion: There was no evidence of subsidence of the stem or osteolysis around the stem despite the polyethylene wear. Conversely, in the Charnley group the stem was the major reason for failure with 12 stems (9.5%) being revised for aseptic loosening. The Kaplan Meier Survivorship at 10 years was 66.6% ± 19.1% for the ABG and ± 82% for the Charnley group. This was not significant

Purpose: To our knowledge, there are no 35 year follow-up studies of the Charnley total hip arthroplasty in the United States. The purpose of the study was to evaluate the results of a single surgeon series of primary Charnley total hip arthroplasties performed with cement at a minimum 35 year follow-up interval. Method: Between July 1970 and April 1972, the senior author performed 330 Charnley total hip replacements with cement using a hand-packing cement technique. At minimum 35 years post-operatively, 13 patients (16 hips) were alive, with 1 patient (1 hip) lost to follow-up. Living patients were evaluated clinically with a standard terminology questionnaire, and WOMAC. Radiographic evaluation included loosening, lysis, and need for reoperation. Results: After a minimum 35 year follow-up, only 25 (8%) acetabular components and 10 (3%) femoral components revised for aseptic loosening. For the 16 hips in living patients, 7 acetabular components (44%) and 2 femoral component (12%) were revised for aseptic loosening. Overall, 87% of the original prosthesis remains intact at the time of final follow-up, or at the time of the patient’s death. The average linear wear rate for all patients with minimum 10 year radiographic follow-up was 0.09 mm/year. Conclusion: Our follow-up study at a minimum 35 years following Charnley total hip arthroplasty with cement demonstrates the remarkable durability of the procedure. As demonstrated in this study, the long term challenge has been revisions associated with bearing surface wear. This study should provide a benchmark for comparison to follow-up studies of other procedures and devices as they reach this interval of follow-up

The pattern and magnitude of pelvic periprosthetic bone loss around cementless metal-backed acetabular implants have previously been described. The pattern of periprosthetic BMD change around cemented all-polyethylene acetabular implants is unreported. The aims of this study were to determine the precision of pelvic BMD measurements around the Charnley cup and to examine the longitudinal pattern of BMD change over the first 2 years after surgery. 19 subjects who had previously received a Charnley cup for osteoarthritis underwent duplicate measurements of pelvic BMD after repositioning using an Hologic QDR 4500A densitometer. Scan analysis was carried out using a 4-region of interest model according to a protocol previously described. In-vivo precision was expressed as coefficient of variation (CV%) for each region of interest. The precision of pelvic periprosthetic BMD measurements were 7.7%, 9.8%, 10.8%, and 9.9% for regions 1 to 4, respectively. Longitudinal BMD changes were measured over a 2 year period in 32 patients (mean age 74 years; 22 women) undergoing cemented THA for unilateral osteoarthritis (17 right-sided). Transient decreases in BMD were observed in regions 2 and 3 (behind the dome of the implant) at 3 months (−9.0% and −13.2%, respectively; P< 0.05) and at 1 year (−8.1% and −9.3%; P< 0.05). By 2 years there had been some recovery in bone mass (BMD−6.9% and −2.6% respectively). No significant changes in BMD for regions 1 and 4 (located at the rim of the implant) were found. The precision of pelvic periprosthetic BMD measurements for the cemented Charnley cup are poorer than those we have previously reported for cementless cups and may be due, in part, to cement artifact. The pattern of BMD change observed for the Charnley implant suggests that load transfer between the implant and the pelvis occurs principally at the implant rim. The magnitude of bone loss is similar to that we have previously reported for cementless metal-backed acetabular implants

Substantial bone loss and bone defects are the most challenging problems faced by the surgeon performing revision surgery. Of the many techniques available, impaction bone grafting aims to achieve stability of an implant with the use of compacted, morselized bone graft and subsequently allows restoration of bone stock by bone ingrowth. This technique was proposed with a highly polished double tapered stem. This technique has also been subsequently used with stems of varying surface finish and shape. We report here our experience with impaction grafting using Charnley stem and variants with 8–10 year results assessing the radiological appearance and subsequent behaviour of the impacted allograft. A prospective radiological study of revision hip arthroplasty done for aseptic loosening with femoral bone loss is presented. Pre operative bone loss was assessed using the Endo Klinik grading system. Impaction grafting with fresh frozen femoral head allograft and the flanged 40 size Charnley stem was used in 17 cases and extra heavey flanged 40 size was used in 9 casaes. Post operative and annual review radiographs were examined for graft distribution, graft consolidation, cortical repair and subsidence of the stem. Twenty six revisions performed in 25 patients between May 1994 and November 1996 were followed up for 8–10 years. Mean age was 66 years(range 26–83 years). There were eighteen male and 7 female patients. One patient died 2 years and 9 months after the operation. Pre operatively Endo Klinik grade 2 bone loss was seen in 7 cases and grade 3 bone loss was seen in 19 cases. Post operative radiographs showed even graft distribution in twenty cases, five patients had poor filling in Gruen zone 3 and one patient had poor filling in zone 2. All cases demonstrated evidence of graft consolidation by one year. Twenty two cases showed no further changes after 8–10 years. Two cases of subsidence have been revised and one patient is awaiting revision ( 8 years after revision). Two of these were extra heavy flanged 40 stems. Three cases showed subsidence > 5mm and were associated with graft deficiency in zone 2 or 3. Out of these three one had an extra heavy flanged 40 stem inserted. There were no medical complications or deep infection following surgery in these patients. One patient had dislocation. In conclusion, femoral revision using impaction grafting with the Charnley stem produces satisfactory radiological results in the medium to long term. Good graft distribution on a postoperative radiograph is associated with graft consolidation, cortical repair and minimal stem subsidence. Extra heavy flanged 40 stems perform less satisfactorily compared to the flanged 40 stems. Inadequate graft filling is associated with stem subsidence and revision. These findings highlight the importance of meticulous surgical technique to ensure even graft distribution. This study supports the taper of the Charnley stem and suggests that a vaquasheen finish is not contraindicated

Introduction: The clinical results of the modular Charnley Elite total hip system have been the subject of some interest in recent years. Some studies have shown significant subsidence and rotational instability in stems when used with low-viscosity cement. These unstable stems have been shown to fail early. The purpose of this study is to demonstrate our conflicting clinical results. Materials and Methods: 616 modular Charnley Elite total hip arthroplasties were inserted between 1995 and 2002 at Wrightington Hospital, which is a tertiary referral centre and centre of excellence for joint replacement in United Kingdom. Both Consultants and trainees performed operations and a variety of surgical approaches were used. Normal viscosity bone cement was used in all patients. All patients were followed up prospectively. Results: At mean follow-up of 8 years (range 5–12), 471 hips were available for review. 87 patients had died and 12 were lost to follow-up. 2.7% (13 cases) of femoral components and 2.9% (14 cases) of acetabular components had been revised for aseptic loosening. 10 hips (2.1%) underwent revision for deep infection and 2 (0.04%) for recurrent dislocation. The overall survival with aseptic loosening as an end point was 97% and for revision for any reason was 94.5%. Conclusion: Our results show acceptable clinical survivor-ship for this implant when used with standard viscosity cement. This contrasts with the lower survivorship rates published by other centres. Our result should reassure patients and surgeons alike that this prosthesis can be associated with acceptable results in the medium term

Background: During the 1990s a change in operative technique for primary hip replacement took place in Norway. This study was designed to measure the revision rate in different time periods in cemented Charnley total hip replacements reported to the Norwegian Arthroplasty Register. Patients and methods: 26 873 primary cemented Charnley total hip replacements reported to the Norwegian Arthroplasty Register in the time periods 1987–91, 92–96, 97–01 and 2002–05 were studied. Only hips with Palacos and Simplex cements with and without antibiotic were studied. To compare the time periods Kaplan Meier analysis was used. To adjust for differences in approach to the hip, age, sex and use of systemic antibiotic prophylaxis Cox regression was used. Results: There was 28 % less risk of revision due to all causes in the time period 1997–01 compared to 1987–91 (RR=0.72 (95% CI 0.60–0.86), p< 0,001). There was inferior result in the time period 1992–96 compared to 1987–91, but from 1997 there has been an improvement of results due to fewer aseptic loosenings of the femoral component (RR 0.44 (95% CI 0.35–0.56), p< 0.001). There was however more luxations in the later period, and there was no improvement in revisions due to aseptic loosening of the acetabular component. Conclusion: There has been an improvement in revision rate of the cemented Charnley prosthesis the last two time periods, due to fewer aseptic loosenings of the femoral component. The reason is probably better technique of component placement and better cementation technique. In the future prevention of luxation and better cementation technique of the acetabulum should also be emphasised

Introduction: The clinical results of the modular Charnley Elite total hip system have been the subject of some interest in recent years. Some studies have shown significant subsidence and rotational instability in some stems when used with low-viscosity cement. These unstable stems have been shown to fail early. This purpose of this study is to demonstrate our conflicting clinical results. Materials and Methods: 616 modular Charnley Elite total hip arthroplasties were inserted between 1995 and 2002 at Wrightington Hospital, which is a tertiary referral centre and centre of excellence for joint replacement in United Kingdom. Both Consultants and trainees performed operations and a variety of surgical approaches were used. Normal viscosity bone cement was used in all patients. All patients were followed up prospectively. Results: At mean follow-up of 8 years (range 5–12), 471 hips were available for review. 87 patients had died and 12 were lost to follow-up. 2.7% (13 cases) of femoral components and 2.9% (14 cases) of acetabular components had been revised for aseptic loosening. 10 hips (2.1%) underwent revision for deep infection and 2 (0.04%) for recurrent dislocation. The overall survival with aseptic loosening as an end point was 97% and for revision for any reason was 94.5%. Conclusion: Our results show acceptable clinical survivor-ship for this implant when used with standard viscosity cement. This contrasts with the lower survivorship rates published by other centres. Our result should reassure patients and surgeons alike that this prosthesis can be associated with acceptable results in the medium term

Ultra high molecular weight polyethylene (UHMWPE) was introduced into clinical practice by Charnley in November 1962 and has remained the standard material for the hip and other total joint arthroplasties. Wear of the UHMWPE cup, although studied from the beginning, did not appear to be a clinical problem although Charnley suspected that this would be so in the long term. A review of the outcome of the Charnley low-friction arthroplasty in patients under the age of 40 years at the time of the operation has shown that the incidence of cup migration was exponentially related to the depth of cup penetration. A prospective study using 22.225 mm alumina ceramic (Al 20 3 ) head articulating with cross linked polyethylene was set up with the initial penetration of 0.2 – 0.4 mm in about 2.5 years with no further penetration. The clinical results mirrored closely the experimental results obtained with the identical set of materials and design. The clinical results have now reached 14 year follow-up and the initial total penetration of 0.2 – 0.4mm has remained unchanged. Review of long term results of the Charnley LFA has shown a mean penetration rate of 0.1 mm/year (0.02 – 0.6). With a mean penetration rate of 0.1 mm/year, the revision rate for cup wear and loosening in patients under the age of 50 at the time of the LFA, and with a follow-up to 32 years, is in the region of 10%. If the penetration rate remained at 0.02 mm/year or less then no cups have been revised for aseptic loosening. Ceramic / UHMWPE articulation is the next stage of evolution of the Charnley LFA. A prospective study using zirconia 22.225 mm head is approaching 7 year follow-up in over 1000 cases

A prospective study of Charnley low friction arthroplasty in patients under the age of 51 at the time of surgery. 1092 patients, 668 women and 424 men, mean age 41 years (12–51) at the time of surgery had 1434 Charnley low-friction arthroplasties carried out between November 1962 and December 1990. At mean follow-up 14.2 years (1 – 32), 742 patients (973 hips) are still attending and patients’ satisfaction with the outcome is 96.2%. Survivorship was 95.24% at 10 years and 58.67% at 27 years. Patients who had had previous hip surgery had revision rate 24.8% compared with 14.1%. Patients with rheumatoid arthritis had fewer revisions than those with developmental hip dysplasia or primary osteoarthritis. Large 43 mm diameter cup gave lower revisions for aseptic cup loosening as compared with 40mm cup. Presence and preservation of subchondral plate, rim support compared to medialization of the cup, use of acetabular cement pressurizer and the reduced diameter neck (10mm) all made a contribution to reducing the incidence of revisions for aseptic cup loosening. Closing the medullary canal with bone block reduced the incidence of aseptic stem loosening. Use of the brace reamers did not affect the outcome and there appears to have been no advantage with the flanged stem. The long-term problem was the increasing incidence of revisions for aseptic cup loosening. This was exponentially related to the depth of cup penetration by the head of the femoral component. The long term clinical results of the Charnley LFA remain excellent even in young patients. Rim support of the cup, preservation of the subchondral bone of the acetabulum, cup flange and pressurising of the acetabular cement all make a significant contribution. Distal closure of the medullary canal and central position of the stem are of benefit, but reaming the medullary canal to cortex must be avoided. The long-term problem has been highlighted again as: wear and cup loosening

The aim of this study was to determine whether there is evidence to support the [often quoted] concept of a threshold effect of implant wear rate on osteolysis risk after total hip arthroplasty (THA). The study design was a case control study of 115 subjects with osteolysis after Charnley THA for idiopathic osteoarthritis (mean age at primary surgery 61.1 years; M:F =49:66; osteolysis-free survival 10.9 years) compared with 115 individually case-matched subjects following Charnley THA for idiopathic osteoarthritis with no current radiographic evidence of osteolysis (mean age 61.3 years; M:F = 49:66; osteolysis-free survival 11.0 years). Calculated median (interquartile range) annual linear wear rate (measured using the EBRA method) was 0.12mm (0.08 to 0.18) and 0.07mm (0.05 to 0.10) in the osteolysis and control groups, respectively (Wilcoxon, P< 0.001). Subjects were divided into wear quintiles based on wear rate (n=46 subjects per quintile). The proportions of osteolysis subjects in each successive wear quintile groups were 0.22, 0.39, 0.48, 0.61, and 0.80 (χ. 2. P< 0.001). The proportion of subjects with osteolysis thus increased in a uniform manner with no evidence of a disproportionate increase between groups. The odds-ratio for osteolysis for each incremental increase in annual linear wear above the median wear rate in the control subjects was 2.4 (logistic regression analysis, 95% CI 1.7 to 3.3, P< 0.001). In summary, the proportion of subjects with osteolysis increases steadily by wear quintile. Our data suggest a continuous gradient of risk for osteolysis associated with increasing annual wear rate in the Charnley prosthesis. We found no evidence to support the concept of a defined threshold above which the risk of osteolysis is disproportionately increased. The implication of this finding is that the goal of advances in bearing surface technologies should be aimed at the elimination of wear, rather than simply it’s reduction to below an arbitrarily-defined level

Introduction: C-stem is a triple taper polished femoral stem. The rationale for this design is to achieve an evenly distributed proximal loading of the cement mantle. This design is thought to enhance stability of the stem inside the mantle and lead to bone remodelling medially. There is to our knowledge no randomized trial comparing this stem to a well documented stem. We chose to compare it to the best documented stem in the Norwegian arthroplasty register, the Charnley monoblock. Methods: 70 patients scheduled for total hip replacement were randomized to either C-stem or Charnley monoblock. All received a 22 mm stainless steel head, OGGEE cup and Palacos Cement with Gentamycin. We used a transgluteal approach in all cases. Harris and Oxford hip scores were measured preoperatively and after two years. Standard X-rays were taken postoperatively and after two years. Radiostereometry (RSA) was done postoperatively and after 3,6,12 and 24 months. Results: There was no significant difference in Harris or Oxford hip scores after two years. RSA after two years: (table deleted). Discussion: Polished tapered stems are designed to sink inside the mantle. Our results confirm this theory for the C-stem. The subsidence is comparable to other collarless tapered stems with good long-term survival. For all other migrations/rotations the C-stem is as stable as the Charnley monoblock. This predicts good long-term results for this stem

Purpose of the study: Long-term outcome of Charn-ley total hip arthroplasty (THA) (more than 30 years follow-up) has demonstrated that the longevity of these prostheses is inversely proportional to polyethylene wear and head penetration into the cup. In order to limit wear phenomena, we have used since 1997 a Charnley THA with a 22.225 mm zirconia (Zr) head (Prozyr®, Saint-Gobain Desmarquet). The goal was to reduce wear and improve implant longevity. Material and methods: We reviewed at minimum five years follow-up 62 patients with 69 THA with a standard Zr/PE bearing. These patients had undergone surgery in 1997–1999, the cup or the high-density PE insert were furnished by Centerpulse Zimmer. The measurement method correlated the Livermore technique with determination of the center of the head using the Chevrot and Kerboull method and interobserver radiological measurements made on digitalized images after magnification. Results: At mean six years follow-up, the Postel-Merle-d’Aubigné score was 17.6 and overall anteroposterior wear at mast follow-up was 0.76 mm (0.73 mm with the Acoplot PE cup and 0.78 mm with the hybrid THA with an isofit cup). Mean wear for this series of implants was thus 0.12 mm/year. There were no fractures of the Zr heads. The rate of osteolysis was 10% with very minimal osteolysis defects, general in the Merckel spine. Wear on the same implant in a previous series operated on in 1997 was 0.40 mm at three years, i.e. also 0.12 mm/year. Discussion: Wear was not greater with the Zr/PE bearing than usually observed with a 22.225 metal-backed PE bearing. This is in contradiction with observations by J. Allain and D. Goutallier in 1999 and with the publication by P. Piriou (SOFCOT 2003). Furthermore, we did not observe, like Hamadouche (SOFCOT 2001) major osteolytic lesions. On the other hand, we did not observe, as was shown by Wroblewsk, any decrease in the rate of penetration of the head into the PE insert. Using the same 22.225 Prozyr bearing with conventional PE and a cemented head, Wbroblewski showed in 2004 that at mean 4.3 years follow-up (range 0–8 years) mean penetration was 0.03 mm/yr. Conclusion: Today, at five years follow-up, we have found that with a Charnley THA wear is the same with the Zr/PE as with the metal/PE bearing

Aim: The dorsal flange stem was introduced following reports of stem fracture using the Charnley “flat-back” stem. This retrospective study reports the outcome using the Flanged Charnley stem in total hip replacement. Materials and methods: Between January 1983 to December 1996, 1170 cemented total hip replacements (915 patients) were performed using the flanged Charnley stem. The main indications were osteoarthritis, rheumatoid arthritis and avascular necrosis. There were 532 females and 383 males aged 32 to 83 years (average 70.2 years). 612 patients were alive at an average follow-up of 16.6 years (9 to 22 years). All operations were performed by the trans-trochanteric or antero-lateral approach. Patients were evaluated using the Charnley’s modification of Merle d’Aubigne system. Results: All patients had an improvement in function following the operation. Aseptic loosening of the stem was noted in 32 patients. Survivorship to revision of the femoral stem was 94% at 10 years (95% CI, 89%–99%) and 90% (95% CI, 81%–99%) at 15 years. The common complications included dislocation, wire breakage and trochanteric non-union. Femoral stem fracture resulted in 1 patient requiring stem revision. Conclusion: The use of the Flanged Charnley stem in total hip replacement gives good long term outcome

With the demand for total hip arthroplasty continuing it is essential that the longest follow-up cases remain under continuous review. Fifty one of the primary Charnley low-frictional torques arthroplasties have passed 30 years follow-up: mean 31 years (30–36): 42 are women and 9 men. Their mean age at surgery was 47 years (24–64). At the latest follow-up two have had a late deep infection, three a dislocation, nine a radiologically loose cup, two a loose stem and one had had a fracture of the shaft of the femur, and one a fractured stem, with only the fractured stem coming to revision. Clinical results remain satisfactory. Wear and loosening of the cup remains the long term problem. Further improvement and even longer follow-up and successful results of the Charnley LFA will come from materials which offer the greatest resistance to wear