Aims

The aim of this retrospective study was to assess the incidence of early periprosthetic femoral fracture (PFF) associated with Charnley-Kerboull (CK) femoral components cemented according to the ‘French paradox’ principles through the Hueter anterior approach (HAA) in patients older than 70 years.

Periprosthetic femoral fracture (PFF) following primary total hip arthroplasty (THA) is of raising concern with the aging of the population. The aim of this retrospective study was to assess the incidence of early PFF associated with Charnley- Kerboull (CK) stems cemented line-to-line according to the “French paradox” principles through the anterior approach (AA) in patients older than 70 years old.

This monocentric study involved 25 surgeons with various level of experience. From a prospectively collected database, all CK stems (AmisK®, Medacta, Castel San Pietro, Switzerland) done consecutively from January 2018 to May 2022 through the AA in patients older than 70 years were included. The measured parameters included canal flare index (CFI), morphological cortical index (MCI), canal-calcar ratio (CCR), ilium-ischial ratio (IIR), ilium overhang, and anterior superior iliac spine (ASIS) to greater trochanter distance. Dorr classification was also recorded.

A total of 416 CK stems performed by 25 surgeons were included. All patients had a minimal 3-month follow-up. The mean age was 77.4 years, and the mean BMI was 25.3 kg/m². According to the Dorr classification 240 hips were of Dorr type A, 144 Dorr type B, and 2 Dorr type C. Mean CFI, MCI, CCR, IIR and ASIS-GT were 3.8, 0.5, 2.8, 2.5, and 101mm, respectively. Amongst the 416 THAs, one (0.24%; 95% CI 0.20 – 0.28%) early PFF Vancouver type B2 fracture that occurred 24 days postoperatively was observed.

This study demonstrated that CK stems cemented according to the “French Paradox” were associated with an extremely low rate of early PFF in patients over 70 years. The observed results are better than those reported with uncemented or taper slip cemented stems. Longer follow-up is warranted to evaluate further rate of fracture that may occur during the bone remodeling process around the femoral component.

The purpose of this study was to compare oxinium versus metal-on-polyethylene wear in two consecutive prospective randomized series of low friction total hip arthroplasty at a minimum 10-year follow-up.

A total of 100 patients with a median age of 60.9 years were randomized to receive either oxinium (50 hips) or metal (50 hips) femoral head. The polyethylene socket was EtO sterilized in the first 50 patients, whereas it was highly cross-linked and remelted (XLPE) in the following 50 patients. The primary criterion for evaluation was linear head penetration measurement using the Martell system by an investigator blinded to the material. Also, a survivorship analysis was performed using wear related loosening revised or not as the end point.

Complete data were available for analysis in 40 hips at a median follow-up of 12.9 years (11 to 14), and in 36 hips at a median follow-up of 12.3 years (10 to 13) in the EtO sterilized and XLPE series, respectively.

In the EtO sterilized series, the mean steady-state wear rate was 0.245 ± 0.080 mm/year in the oxinium group versus 0.186 ± 0.062 mm/year in the metal group (p = 0.009). In the XLPE series, the mean steady-state wear rate was 0.037±0.016 mm/year in the oxinium group versus 0.036±0.015 mm/year in the metal group (p = 0.94). The survival rate at 10 years was 100% in both XLPE series, whereas it was 82.9% (IC 95%, 65–100) and 70.5% (IC95%, 50.1–90.9) in the metal-EtO and oxinium-EtO series, respectively.

This RCT demonstrated that up to 14-year follow-up, wear was significantly reduced when using XLPE, irrespective of the femoral head material. Also, no osteolysis related complication was observed in the XLPE series. In the current study, oxinium femoral heads showed no advantage over metal heads and therefore their continued used should be questioned related to their cost.

Polyethylene wear-debris induced inflammatory osteolysis is known as the main cause of aseptic loosening and long term revision total hip arthroplasty. Although recent reports suggest that antioxidant impregnated ultra-high molecular weight polyethylene (UHMWPE) wear-debris have reduce the osteolytic potential in vivo when compared to virgin UHMWPE, little is known about if and/or how PE rate of oxidation affects osteolysis in vivo. We hypothesized that oxidized UHMWPE particles would cause more inflammatory osteolysis in a murine calvarial bone model when compared to virgin UHMWPE.

Male C57BL/6 eight weeks old received equal amount of particulate debris overlaying the calvarium of (n=12/group): sham treatment (no particles), 2mg (6,75×107 particles/mg) of endotoxin-free UHMWPE particles (PE) or of endotoxin-free highly oxidized-UHMWPE (OX) particles. In vivo osteolysis was assessed using high resolution micro-CT and inflammation with L-012 probe dependent luminescence. At day 10, calvarial bone was examined using high resolution micro-CT, histomorphometric, immunohistochemistry analyses and qRT-PCR to assess OPG, RANK, RANK-L, IL-10, IL-4, IL-1b and TRAP genes expression using the protocol defined by individual TaqManTM Gene Expression Assays Protocol (Applied Biosystems).

In vivo inflammation was significantly higher in the OX (1.60E+06 ± 8.28E+05 photons/s/cm2) versus PE (8.48E+05 ± 3.67E+05) group (p=0.01). Although there was a statistically significant difference between sham (−0.27% ± 2.55%) and implanted (PE: −9.7% ± 1.97%, and OX: − 8.38% ± 1.98%) groups with regards to bone resorption (p=0.02), this difference was not significant between OX and PE (p = 0.14). There was no significant difference between groups regarding PCR analyses for OPG, RANK, RANK-L, IL-10, IL-4, IL-1b and TRAP (p = 0.6, 0.7, 0.1, 0.6, 0.3, 0.4, 0.7 respectively). Bone volume density was significantly decreased in PE (13.3%±1.2%) and OX (12.2%±1.2%) groups when compared to sham (15%±0.9%) (p < 0 .05). Histomorphometric analyses showed a significantly decreased Bone Thickness/Tissue Thickness ratio in the implanted group (0.41±0.01 mm and 0.43±0.01 mm) compared to sham group (0.69± 0.01) (p < 0 .001). However, there were no significant difference between OX and PE (p = 0.2).

Our findings suggest that oxidized UHMWPE particles display increased inflammatory potential. Results were not significant regarding in vivo or ex vivo osteolysis. As antioxidant-diffused UHMWPE induce less inflammation activity in vivo, the mechanism by which they cause reduced osteolysis requires further investigation.

Aims

The purpose of this retrospective study was to evaluate the minimum five-year outcome of revision total hip arthroplasty (THA) using the Kerboull acetabular reinforcement device (KARD) in patients with Paprosky type III acetabular defects and destruction of the inferior margin of the acetabulum.

The purpose of this study was to compare the effect of femoral head material (delta ceramic versus metal) on polyethylene wear in a consecutive prospective randomized series of low friction total hip arthroplasty.

A total of 110 patients with a mean age of 60.6 ± 9.3 (34–75) years were randomized (power of 90%, alpha of 5%) to receive either a metal (55 hips) or a delta ceramic (55 hips) femoral head. The polyethylene socket was moderately cross-linked (3 Mrads of gamma radiation in nitrogen) and annealed at 130°C in all hips. All other parameters were identical in both groups. The primary criterion for evaluation was linear head penetration measurement using the Martell system, performed by an investigator blinded to the material of the femoral head. Creep and steady state wear values were calculated.

At the minimum of 3-year follow-up, complete data were available for analysis in 38 hips at a median follow-up of 4.4 years (3.0 to 5.7), and in 42 hips at a median follow-up of 4.0 years (3.0 to 5.4) in the metal and delta ceramic groups, respectively. The mean creep, measured as the linear head penetration at one year follow-up, was 0.42 ± 1.0 mm in the metal group versus 0.30 ± 0.81 mm in the delta ceramic group (Mann and Whitney test, p = 0.56). The mean steady state penetration rate from one year onwards measured 0.17 ± 0.44 mm/year (median 0.072) in the metal group versus 0.074 ± 0.44 mm/year (median 0.072) in the delta ceramic group (Mann and Whitney test, p = 0.48). No case of delta ceramic femoral head fracture was recorded, and no hip had signs of periprosthetic osteolysis.

This study demonstrated that up to 5-year follow-up, delta ceramic femoral head did not significantly influence creep neither wear of a contemporary annealed polyethylene. Longer follow-up is necessary to further evaluate the potential clinical benefits of delta ceramic.

Introduction

The causes for revision of primary total hip arthroplasty (THA) are various and quite well known. The developing use of dual-mobility THA (DM-THA) seems a relevant option to decrease the risk of instability. Due to lack of long-term follow-up, this innovative retentive concept is suspected to increase the risk of polyethylene (PE) wear. The aim of the study was to analyse the causes for DM-THA revision and assess whether or not its occurrence is different from that of fixed-standard (FS) THA, particularly for aseptic loosening or wear and/or osteolysis.

Previous standards for assessing the reliability of a measurement tool have lacked consistency. We reviewed the most current American Society for Testing and Materials and International Organisation for Standardisation (ISO) recommendations, and propose an algorithm for orthopaedic surgeons. When assessing a measurement tool, conditions of the experimental set-up and clear formulae used to compile the results should be strictly reported. According to these recent guidelines, accuracy is a confusing word with an overly broad meaning and should therefore be abandoned. Depending on the experimental conditions, one should be referring to bias (when the study protocol involves accepted reference values), and repeatability (sr, r) or reproducibility (SR, R). In the absence of accepted reference values, only repeatability (sr, r) or reproducibility (SR, R) should be provided.

Take home message: Assessing the reliability of a measurement tool involves reporting bias, repeatability and/or reproducibility depending on the defined conditions, instead of precision or accuracy.

Cite this article: Bone Joint J 2016;98-B2:166–72.

Most published randomised controlled trials which compare the rates of wear of conventional and cross-linked (XL) polyethylene (PE) in total hip arthroplasty (THA) have described their use with a cementless acetabular component.

We conducted a prospective randomised study to assess the rates of penetration of two distinct types of PE in otherwise identical cemented all-PE acetabular components.

A total of 100 consecutive patients for THA were randomised to receive an acetabular component which had been either highly XL then remelted or moderately XL then annealed.

After a minimum of eight years follow-up, 38 hips in the XL group and 30 hips in the annealed group had complete data (mean follow-up of 9.1 years (7.6 to 10.7) and 8.7 years (7.2 to 10.2), respectively). In the XL group, the steady state rate of penetration from one year onwards was -0.0002 mm/year (sd 0.108): in the annealed group it was 0.1382 mm/year (sd 0.129) (Mann–Whitney U test, p < 0.001). No complication specific to either material was recorded.

These results show that the yearly linear rate of femoral head penetration can be significantly reduced by using a highly XLPE cemented acetabular component.

Cite this article: Bone Joint J 2015;97-B:1458–62.

Conventional cemented acetabular components are reported to have a high rate of failure when implanted into previously irradiated bone. We recommend the use of a cemented reconstruction with the addition of an acetabular reinforcement cross to improve fixation.

We reviewed a cohort of 45 patients (49 hips) who had undergone irradiation of the pelvis and a cemented total hip arthroplasty (THA) with an acetabular reinforcement cross. All hips had received a minimum dose of 30 Gray (Gy) to treat a primary nearby tumour or metastasis. The median dose of radiation was 50 Gy (Q1 to Q3: 45 to 60; mean: 49.57, 32 to 72).

The mean follow-up after THA was 51 months (17 to 137). The cumulative probability of revision of the acetabular component for a mechanical reason was 0% (0 to 0%) at 24 months, 2.9% (0.2 to 13.3%) at 60 months and 2.9% (0.2% to 13.3%) at 120 months, respectively. One hip was revised for mechanical failure and three for infection.

Cemented acetabular components with a reinforcement cross provide good medium-term fixation after pelvic irradiation. These patients are at a higher risk of developing infection of their THA.

Cite this article: Bone Joint J 2015;97-B:177–84.

In this study we randomised 140 patients who were due to undergo primary total knee arthroplasty (TKA) to have the procedure performed using either patient-specific cutting guides (PSCG) or conventional instrumentation (CI).

The primary outcome measure was the mechanical axis, as measured at three months on a standing long-leg radiograph by the hip–knee–ankle (HKA) angle. This was undertaken by an independent observer who was blinded to the instrumentation. Secondary outcome measures were component positioning, operating time, Knee Society and Oxford knee scores, blood loss and length of hospital stay.

A total of 126 patients (67 in the CI group and 59 in the PSCG group) had complete clinical and radiological data. There were 88 females and 52 males with a mean age of 69.3 years (47 to 84) and a mean BMI of 28.6 kg/m² (20.2 to 40.8). The mean HKA angle was 178.9° (172.5 to 183.4) in the CI group and 178.2° (172.4 to 183.4) in the PSCG group (p = 0.34). Outliers were identified in 22 of 67 knees (32.8%) in the CI group and 19 of 59 knees (32.2%) in the PSCG group (p = 0.99). There was no significant difference in the clinical results (p = 0.95 and 0.59, respectively). Operating time, blood loss and length of hospital stay were not significantly reduced (p = 0.09, 0.58 and 0.50, respectively) when using PSCG.

The use of PSCG in primary TKA did not reduce the proportion of outliers as measured by post-operative coronal alignment.

Cite this article: Bone Joint J 2015;97-B:56–63.

Osteoporosis following ovariectomy has been suggested to modulate bone response to polyethylene wear debris. In this work, we evaluate the influence of estrogen deficiency on experimental particle-induced osteolysis. Polyethylene (PE) particles were implanted onto the calvaria of wild-type (WT), sham-ovariectomized (OVX), OVX mice and OVX mice supplemented with estrogen (OVX+E2) (12 mice per group). Sham-implanted mice served as internal controls. After 14 days, seven skulls per group were analyzed with a high-resolution micro-computed tomography (CT) and by histomorphometry, and for tartrate-specific alkaline phosphatase. Five calvariae per group were cultured for the assay of IL-1, IL-6, TNF- and RANKL secretion using quantitative ELISA. The expression of RANKL and OPG mRNA were evaluated using real-time PCR. As assessed by CT and by histomorphometry, PE particles induced an extensive bone resorption and an intense inflammatory reaction in WT, sham-OVX and OVX+E2 mice. In OVX mice group, these features appeared considerably attenuated. In WT, sham-OVX and OVX+E2 mice, PE particles induced an increase in serum IL-6, in TNF-and RANKL local concentrations, and resulted in a two-fold increase in RANKL/OPG mRNA ratio. Conversely, these parameters remained unchanged in OVX mice after PE implantation. The combination of two well-known bone resorptive mechanisms ultimately attenuated osteolytic response, suggesting a protective effect of estrogen deficiency on particle-induced osteolysis. This paradoxical phenomenon was associated with a downregulation of pro-resorptive cytokines. It is hypothesized that excessive inflammatory response was controlled, illustrated by the absence of increase of serum IL-6 in OVX mice after PE implantation.

Introduction

The purpose of this study was to evaluate the in vivo migration patterns of a polished femoral component cemented line-to-line using EBRA –FCA.

Introduction

The purpose of this prospective randomized study was to compare the 2-year follow-up penetration of Oxinium versus Metal on polyethylene in a consecutive series of low friction total hip arthroplasty.

Introduction

Several devices based upon the dual mobility (DM) concept have recently been FDA approved. However, little is available on the efficiency of current DM on THA instability prevention, and on specific complications. The aim of this retrospective study was to report on the minimal 5-year follow-up results of a cementless DM socket.

Purpose of the study: Oestrogen depletion leads to osteoclastic hyperactivity and subsequent postmenopausal osteoporosis. Little is known about interactions with bone absorption induced by wear particles from joint bearings. The purpose of this study was to evaluate bone response to polyethylene (PE) particles in a mouse model of oestrogen deficiency.

Material and methods: Particles of PE were implanted in the calvaria of seven non-ovariectomised mice and in seven ovariectomised mice (OVX). Fourteen mice were operated on without implantation of the particles (7 non-OVX and 7 OVX, control groups). The mice were sacrificed at two weeks. The crania were studied under a microscanner and histologically without decalcification.

Results: The microscanner showed that particles of PE induced a significant decrease in bone thickness in non-OVX mice (p=0.04), while the thickness remained unchanged in OVX mice who had received the particles (p=0.40). After implantation of the PE particles, the number of osteoclasts per mm of bone perimeter was 2.84±1.6 in the non-OVX mice and 1.74±1.3 in OVX mice (p=0.004). Compared with controls, the mean loss of bone was 12±10% in the non-OVX mice versus 4.7±0.9%in the OVX mice (p=0.004).

Discussion: The volume of osteolysis induced by PE particles was smaller in OVX mice compared with non-OVX mice.

Conclusion: These results suggest that a deficit in oestrogens has a protective effect against bone adsorption induced by PE particles.

Purpose of the study: The purpose of this prospective study was to evaluated the risk of fracture of 22.2 mm Delta ceramic heads.

Material and methods: A preclinical study was performed on twenty 22.2 mm Delta ceramic femoral heads with a medium neck with 20 22.2 mm Delta ceramic femoral heads with a short neck. A V40TM cone was used in all cases with a 5 40 angle. In vitro tests consisted in the assessment of the fracture force under static pressure before and after stress tests, and with a static force shock test (Charpy model) simulating a microseparation during subluxation phenomena. Between April 2007 and April 200, a consecutive series of 55 composite Delta heads were used in 55 patients undergoing cemented total hip arthroplasty (THA). A polyethylene cup was sterilised under vacuum at 3 Mrads with a post-radiation temper (Duration^®), and a stainless steel femoral piece with a highly polished surface and a V40TM Morse cone (Legend^®). This series issued from a randomised prospective study designed to compare wear with 22.2mm Delta ceramic heads with stainless steel heads with the same diameter. Inclusion criteria were age < 75 years, degenerative disease on naive hip and patient residing in France. Mean patient age was 59.2±6.9 years (range 44–70).

Results: The resistance of the 22.2 mm heads was significantly less during the static tests before and after the stress tests. Nevertheless, the mean resistance was higher than the FDA recommendations of 46K. The tests simulating a microseparation showed a significantly superior resistance for the 22.2 mm heads. All patients had from 1 to 2 years follow-up (usual delay for 80% of in vivo ceramic fractures). There were no cases of femoral head fracture in this series. There were no cases of early wear at this same follow-up and no case of femoral or acetabular osteolysis.

Discussion and Conclusion: The results of this study indicate that the resistance of the 22.2mm ceramic Delta heads is very much superior to the recommendations for in vitro tests. In this series, the risk of fracture in vivo remained nil to two years follow-up. The pertinence of this ceramic implant for decreasing polyethylene wear in vivo is under evaluation.

Purpose of the study: The purpose of this prospective randomised study was to evaluate the wear of cemented polyethylene cups as a function of the material of the femoral head: oxinium versus metal.

Material and methods: This series included 50 primary arthroplasties implanted from January 2006 to May 2006 in 50 patients (27 women and 23 men), mean age 60.6±11.4 years (21–75). The same femoral piece made of highly polished M30NW stainless steel with a quadrangular section was used for all implants. Similarly, all patients had a polyethylene cup sterilised with ethylene oxide (CMK21, Smith and Nephew). The femoral head was made of stainless steel for 25 hips and oxinium for 25 hips. The major outcome was penetration of femoral head into the cup (associated with true wear and creep) measured at minimum two years follow-up using the Martell method modified according to the recommendations of the author for an all-polyethylene cup. Patient-related and technique-related factors were studied. Non-parametric tests were used for the statistical analysis.

Results: There was no significant difference between the two groups regarding preoperative data. Two patients died, one was lost to follow-up; for three patients, the radiographs were excluded by the software. The analysis thus included 44 hips with a median follow-up of 2.01 years (1.9–2.3), 22 in the Oxinium™ group and 22 in the metal group. The median penetration rate was 0.16 mm/year in the Oxinium^® group versus 0.19 mm/year in the metal group (Mann-Whitney, p=0.46). Annual volumetric penetration in the Oxinium™ group was comparable with that of the metal group (Mann-Whitney, p=0.76). conversely, using the radiograph taken at one year as the reference value (true wear), wear was 0.066 mm/y in the Oxinium™ group versus 0.19mm/y in the metal group (Mann-Whitney, p=0.38).

Discussion and Conclusion: The results of this series indicate that using an oxinium femoral head reduces polyethylene wear. Mid-term results appear to be necessary to confirm these findings.

Introduction: The aim of this study was to evaluate the in vivo migration patterns using EBRA-FCA of a consecutive series of polished femoral components cemented line-toline.

Materials and Methods: Between January 1988 and December 1989, 164 primary total hip arthroplasties were performed in 155 patients. The mean age at the time of the index arthroplasty was 63.8 ± 11.6 years. A single design prosthesis was used combining an all-polyethylene socket and a 22.2 mm femoral head. The mono-block double tapered (5.2°) femoral component made of 316-L stainless steel had a highly polished surface (Ra = 0.04 μm) and a quadrangular section(Kerboull^® MKIII, Stryker). The femoral preparation included removal of diaphyseal cancellous bone to obtain primary rotational stability of the stem prior to the line-to-line cementation. For each patients, all available AP radiographs of the pelvis were digitized (Vidar Sierra Plus, Vidar System Corporation, Herdon, Virginia) and linked to an IMB-compatible computer. The EBRAFCA software is a validated method designed to assess migration of a femoral component through comparable pairs of radiographs.

Results: At the minimum 15-year follow-up, 73 patients (77 hips) were still alive and had not been revised at a mean of 17.3 ± 0.8 years (15–18 years), 8 patients (8 hips) had been revised for high polyethylene wear associated with periacetabular osteolysis, 66 patients (69 hips) were deceased, and 8 patients (10 hips) were lost to follow-up. Among the 8 revision procedures, the femoral component was loose in 3 hips. A total of 1689 radiographs (mean 10.3 per hip) were digitized. At the last follow-up, the mean subsidence of the entire series was 0.63 ± 0.49 mm (median of 0.61 mm; range 0 to 1.94 mm). When using a 1.5 mm threshold (accuracy of the EBRAFCA method) for subsidence, 4 of the 142 stems with adequate EBRA-FCA data were considered to have migrated. Using a threshold of 2 mm for subsidence, none of the 142 stems were considered to have migrated. The patterns of migration were calculated every 2 years giving 9 intervals. The evolution of mean subsidence during the whole follow-up period remained below 1.5 mm.

Discussion: Mean subsidence of this quadrangular highly polished femoral component remained below the accuracy of the method (± 1.5 mm) throughout the entire follow-up period. Of the 142 hips analyzed, only four (2.8%) had subsided of more than 1.5 mm and none more than 2 mm. This study demonstrates that contrary to other cemented femoral components that have provided excellent survival in the long term frequently associated with stem subsidence, a highly polished cemented double tapered femoral component with a quadrangular cross-section cemented line to line does not subside up to 18-year follow-up.

Introduction: Although a number of methods have been described to treat recurrent dislocation following total hip arthroplasty, this complication remains a challenging problem. The purpose of this retrospective study was to evaluate the minimum 2-year outcome in a consecutive series patients treated with a cemented tripolar unconstrained acetabular component for recurrent dislocation.

Patients and Methods: Fifty-one patients presenting with recurrent dislocation following primary or revision total hip arthroplasty in the absence of an identifiable curable cause were treated with a cemented tripolar unconstrained acetabular component. There were thirty-nine females and twelve males with a mean age at the time of the index procedure of 71.3 years. A single acetabular component design was used consisting of a stainless steel outer shell with grooves for cement fixation with a highly polished inner surface. This shell articulated with a mobile intermediate component with an opening diameter smaller than the 22.2-mm femoral head. No locking ring or other mean of constraint was associated.

Results: Of the fifty-one patients, forty-seven have had complete clinical and radiological evaluation data at a mean follow-up of 31.2 months (twenty-four to 56.3 months). The cemented unconstrained tripolar acetabular component restored complete stability of the hip in forty-nine patients (96%). The mean Merle d’Aubigné hip score was 15.8 ± 2.0 at the latest follow-up. Radiographic analysis revealed no or radiolucent lines less than 1 mm thick located in a single acetabular zone in forty-three of forty-seven hips (91.5%). The cumulative survival rate of the acetabular component at 36 months using revision for dislocation and/or mechanical failure as the end point was 93.3 ± 4.6% (95% confidence interval, 84.4% to 100%).

Conclusion: A cemented tripolar unconstrained acetabular component was highly effective in the treatment of recurrent dislocation with none of the complications associated with constrained devices. However, because longer term follow-up is needed to warrant that dislocation and loosening rates will not increase, the use of such a device should be limited to strict indications.

Introduction: The purpose of this study was to report on the minimal 10-year followup results of a prospective randomized and a historical series of low friction cemented hip arthroplasties according to the surface finish of the femoral implant.

Patients and Methods: The prospective randomized series included 284 patients (310 hips) with a mean age of 64.1 years. Among these 310 hips, the femoral component had a highly polished surface (Ra = 0.04 micron, MKIII, Stryker) in 165 hips, and a matte surface finish (Ra = 1.7 microns, CMK3, Vector Orthopedique) in the remaining 145 hips. The historical series that was operated by the sames surgeons according to the same surgical technique included 111 patients (123 hips) with a satin finish femoral component (Ra = 0.9 micron, CMK2, Sanortho). Clinical results were rated according to the Merle d’Aubigne hip score. Radiologic analysis was performed according to the criteria of Barrack et al. for the definition of loosening. Moreover, a survival analysis according to the actuarial method was conducted.

Results: At the minimum 10-year follow-up evaluation, 43 patients (48 hips) were lost to follow-up (0.3 to 8.7 years), 80 patients (83 hips) were deceased (0.1 to 13.6 years), 26 patients had revision of either or both components (0.9 to 15.9 years), and 246 patients (276 hips) were alive and had not been revised after a mean 12.3 ± 1.9 years (10 to 16 years). Radiologic loosening of the femoral component, including revision, occured in one, four, and 15 hips for the polished, stain, and matte groups, respectively. The survival rate at 13 years of the femoral component, using loosening as the end point, was 97.3 ± 2.6% (95% CI, 92.2 to 100%), 97.1 ± 2.1% (95% CI, 93 to 100%), and 78.9 ± 5.8% (95% CI, 67.6 to 90.3%) for polished, satin, and matte stems, respectively.

Discussion: This study demonstrated that cement fixation of a femoral component was more reliable in the long term with a polished or satin surface finish. Based upon our results and the review of the literature, we recommend abondoning the use of cemented stems with a surface roughness greater than 1 micron.

We have evaluated the in vivo migration patterns of 164 primary consecutive Charnley-Kerboull total hip replacements which were undertaken in 155 patients. The femoral preparation included removal of diaphyseal cancellous bone to obtain primary rotational stability of the stem before line-to-line cementing. We used the Ein Bild Roentgen Analyse femoral component method to assess the subsidence of the femoral component.

At a mean of 17.3 years (15.1 to 18.3) 73 patients were still alive and had not been revised, eight had been revised, 66 had died and eight had been lost to follow-up. The mean subsidence of the entire series was 0.63 mm (0.0 to 1.94). When using a 1.5 mm threshold, only four stems were considered to have subsided. Our study showed that, in most cases, a highly polished double-tapered stem cemented line-to-line does not subside at least up to 18 years after implantation.

We describe 129 consecutive revision total hip replacements using a Charnley-Kerboull femoral component of standard length with impaction allografting. The mean follow-up was 8.2 years (2 to 16). Additionally, extramedullary reinforcement was performed using struts of cortical allograft in 49 hips and cerclage wires in 30.

There was one intra-operative fracture of the femur but none later. Two femoral components subsided by 5 mm and 8 mm respectively, and were considered to be radiological failures. No further revision of a femoral component was required. The rate of survival of the femoral component at nine years, using radiological failure as the endpoint, was 98%. Our study showed that impaction grafting in association with a Charnley-Kerboull femoral component has a low rate of subsidence. Reconstruction of deficiencies of distal bone with struts of cortical allograft appeared to be an efficient way of preventing postoperative femoral fracture for up to 16 years.

Purpose of the study: The purpose of this propsective randomized study was to evaluate wear resistance of cemented polyethylene cups with the same design but regular or crosslinked polyethylene.

Material and methods: This series included 144 first-intention arthroplasties implanted between July 2000 and July 2002 in 137 patients (92 females, 45 males), mean age 66.2 years (range 16–88 years). The same femoral piece ws used in all patients with a 22.2 mm head. The cup was made of highly crosslinked polyethylene (Durasul™, Zimmer) for 83 hips and regular polyethylene (Duration™, Stryker) for 61 hips). The main outcome criterion was penetration of the femoral head into the cup at two years minimum follow-up (associating true wear and creep) measured with the Martell method modified by the cup manufacturer’s recommendations. Influence of patient-related factors and surgery-related factors was assessed. Non-parametric statistical tests were applied.

Results: The two groups of patients were not significantly different preoperatively. Two patients in the Durasul™ group died at 14 and 31 months follow-up. Median follow-up for the 137 survivors (142 hips) was 28.8 months (range 3–48.8 months) in the Durasul™ group and 24.8 months (ragne 0–47.9) in the Duration™ group. Among these 142 hips, 66 in the Durasul™ group and 51 in the Duration ™ group were reviewed clinically and radiographically with at least two years follow-up. The median penetration was 0.104 mm/yr in the Durasul™ group and 0.242 mm/yr in the Duration™ group (Mann-Whitney test, p=0.01, power 78%). There was a highly significant negative correlation between follow-up time and wear in the Duration™ group (Spearman r = −0.4, p=0.005) but no significant correlation in the Dursul™ group (Spearman r = −0.2, p=0.06).

Discussion and conclusion: The results of this series indicate a notable reduction in wear for highly cross-linked polyethylene cups, with no specific material-related complication. Mid-term results would however be necessary to validate these findings.

We carried out a prospective randomised study designed to compare the penetration rate of acetabular polyethylene inserts of identical design but different levels of cross-linking at a minimum of four years follow-up. A total of 102 patients (102 hips) were randomised to receive either highly cross-linked Durasul, or contemporary Sulene polyethylene inserts at total hip replacement. A single blinded observer used the Martell system to assess penetration of the femoral head. At a mean follow-up of 4.9 years (4.2 to 6.1) the mean femoral head penetration rate was 0.025 mm/year (sd 0.128) in the Durasul group compared with 0.106 mm/year (sd 0.109) in the Sulene group (Mann-Whitney test, p = 0.0027). The mean volumetric penetration rate was 29.24 mm³/year (sd 44.08) in the Durasul group compared with 53.32 mm³/year (sd 48.68) in the Sulene group. The yearly volumetric penetration rate was 55% lower in the Durasul group (Mann-Whitney test, p = 0.0058). Longer term results are needed to investigate whether less osteolysis will occur.

Introduction: The purpose of this retrospective study was to report on the minimal 5-year follow-up results of a consecutive series of cemented total hip arthroplasties following acetabular fracture.

Materials and methods: Between January 1980 and December 1995, fifty-three total hip arthroplasties were performed in 53 patients (16 females and 37 males). The mean age of the patients at the time of the index arthroplasty was 53.1 years (range, 24–84 years). The initial fracture concerned one wall in 18 patients, one column in 7, and both columns in 6. It was a complex fracture in 11 patients, and was unknown in the remaining 11 patients. Twenty-three of the 53 fractures had had a non-operative treatment, while 30 had had a surgical treatment. The mean time between the fracture and the arthroplasty was 16.4 10.8 years. All prostheses were of Charnley-Kerboull design, combining a 22.2-mm femoral head and an all-polyethylene socket. Both components were cemented.

Results: At the minimum 5-year follow-up evaluation, 35 patients were still alive and had not been revised at a mean of 12.4 3.8 years (range, 7–21 years), 6 patients had been revised, 5 patients had died from unrelated causes, and 7 patients were lost to follow-up. The mean Merle d’Aubigne hip score was 16.7 1.3 at the latest follow-up. Revision was performed for high polyethylene wear associated with periprosthetic osteolysis in 5 hips at a mean of 10.3 years, and for deep sepsis in one. The survival rate of the whole series at 15 years, using revision for any reason as the end-point, was 79.2 9.7 % (95% confidence interval, 60.3 to 98.2%). The survival rate at 15 years, using radiologic loosening as the end-point, was 94.7 % (95% confidence interval, 84.7 to 100%) for hips of which fracture had been treated non-operatively, versus 75.5 13.0% (95% confidence interval, 49.9 to 100%) for hips of which fracture had been surgically treated. The difference was not significant with the numbers available (log-rank test, p = 0.44).

Discussion and conclusion: The results of this series indicated that the mechanical failure rate of total hip arthroplasty following acetabular fracture was high in the mid- to long-term. The young age of the patients, the predominantly male cohort, and the modifications of the acetabulum structure due to the fracture could account for this phenomenon.

Purpose: The purpose of this retrospective study was to evaluate the clinical and radiological results of Charnley-Keroboull total hip arthroplasty performed in patients aged less than 50 years. We searched for factors which might affect wear and sustained fixation.

Material and methods: Among the 2,804 arthroplasties performed in patients aged less than 50 years between 1975 and 1995, we selected randomly 287 (10% of the annual operations). These prostheses were implanted in 222 patients (144 women and 78 men), mean age 40.1±8 years (15–50). All of the arthroplasties were inserted via a transtrochanteric approach. Charnley-Kerboull implants were cemented in all patients using a metal polyethylene bearing. Functional outcome was assessed with the Postel-Merle-d’Aubigné score. Cup wear was measured with the Chevrot technique. The actuarial method was used to calculate prosthesis survival.

Results: At last follow-up, 155 patients (210 hips) were living and had not had a revision procedure at mean 16.1±4.6 years, 23 patients (25 hips) required revision of the acetabular or femoral element, ten patients (10 hips) had died, and 34 patients (42 hips) were lost to follow-up. The mean preoperative functional score was 9.6±2.5 (9–15) versus 17.2±0.8 (9–18) at last follow-up (Wilcoxon rank test p< 0.001). For the acetabular element, there was certain loosening in 15 hips and possible loosening in 24. For the femoral element, loosening was certain for 12 implants and possible for four. Twentyfive hips required revision, including 17 for aseptic loosening. Mean wear was 0.12±0.21 mm (0–2.23). Among the 287 hips, 196 had wear measured at less than 0.1 mm/yr (mean 0.02 mm/yr). Mean overall implant survival, defining revision as failure, was 85.4±5.0% at twenty years (95%CI 78.4–92.4). Among the factors tested, only abnormally rapid wear (> 0.1 mm/yr) was predictive of failure.

Discussion: The results of this series allow us to conclude that total hip arthroplasty using a Charnley-Kerboull implant remains the best solution for young patients in terms of implant survival.

Purpose: Certain authors have indicated that the primum movens of loosening of cemented femoral stems is related to the decohesion of the cement implant interface. Under such conditions, improvement in this interface was attempted with the development of a rough surface for the femoral piece. The purpose of this retrospective analysis was to evaluate results a minimum ten years follow-up in a consecutive series of total hip arthroplasties comparing types of femoral implant surfaces.

Material and methods: Between January 1988 and December 1989, 311 THA were implanted in 286 patients aged 63.6±11.8 years (26–91). All implantations were performed via the transtrochanteric approach by two senior surgeons. Two types of femoral implant were used: 166 non-polished pieces with a round section Ra = 3 mm (CMK3, Vector Orthopédique) and 145 polished pieces with a quadrangular section Ra = 0.4 mm (MKIII, Stryker Howmedica). The preoperative data were comparable for the two groups. Functional results were assessed with the Postel Merle d’Aubigné score (PMA). Actuarial survival curves were plotted.

Results: At minimum ten years follow-up, 187 patients (204 hips) were living and had not required revision at mean follow-up of 11.7±2.5 years (10–14), 15 patients (15 hips) had revision of the acetabular and/or femoral element, 54 patients (58 hips) had died, and 30 patients (34 hips) were lost to follow-up. The mean preoperative function score was 11.2±2.5 (4–16) versus 17.5±0.5 (10–18) at last follow-up (Wilcoxon rank test, p< 0.001). Cumulative survival at 13 years, taking radiographic loosening of the femoral piece as the endpoint, was 78.9±5.8% (95%CI 67.6–90.3%) for unpolished implants versus 97.3±2.6 (95%CI 92.2–100) for polished implants. The difference was significantly different (p< 0.001).

Discussion: The results of this analysis indicate that radiographic survival of unpolished cemented femoral pieces is significant inferior compared with polished pieces. The increased adherence of the femoral cement is probably the cause of increased shear stress at the bone-cement interface. The respective influence of section and surface remain to be determined.

Aims: The purpose of this retrospective study was to report on the minimum 10-year follow-up results of a consecutive series of cemented low friction total hip arthroplasties performed for avascular necrosis of the femoral head. Methods: One hundred and twenty-two THAs in 96 patients were performed between January 1980 and December 1990. All prostheses were of Charnley- Kerboull design, combining a 22.2-mm femoral head and an all-polyethylene socket. Both components were cemented. The mean age of the series was 50.8 ± 13.3 years (21–85 years). Eighty hips were graded Ficat III and 42 hips were graded Ficat IV. Results: At the minimum 10-year follow-up evaluation, 59 patients (75 hips) were still alive and had not been revised at a mean of 13.9 years (10–21 years), 7 patients (7 hips) had been revised, 20 patients (24 hips) had died from unrelated causes, and 10 patients (16 hips) were lost to follow-up. The mean dñAubignŽ hip score was 17 ± 1 at the latest follow-up. The mean wear rate for unrevised hips was 0.07± 0.06 mm per year. Revision was performed for polyethylene wear associated with periprosthetic osteolysis in 6 hips and for deep sepsis in one. Three hips had recurrent dislocations. The survival rate at 15 years, using revision for any reason as the end-point, was 88.5% (95% conþdence interval, 80.2 to 96.9%). Conclusions: This series indicated that Charnley Kerboull low friction total hip arthroplasty for avascular necrosis could provide satisfactory long-term clinical and radiologic results.

Purpose: Nonunion of the trochanter after total hip arthroplasty using the transtrochanteric approach is a serious complication. Incidence is estimated at 3%. Failure after simple cerclage reaches 40%. A plate was therefore designed specifically for fixation of trochanteric fractures. The purpose of this retrospective analysis was to assess outcome in a continuous series of trochanteric fractures treated with this plate.

Material and methods: The series included 72 nonunions in 71 patients treated between 1986 and 1999. Mean age was 66 years. Most of the arthroplasties had been performed for primary degenerative joint disease or for hip dysplasia. The time interval between artrhoplasty and treatment of the nonunion was eight months on the average. The trochanter was fixed with a plate alone in 47 hips and in combination with a frontal wire in 25. The primary outcome criterion was trochanter healing scored as: union (pain free hip, radiological fusion and stability), nonunion (lack of radiological fusion and/or presence of an instability), and doubtful union (moderate pain, no instability, radiological fusion difficult to affirm).

Results: Mean follow-up was 47 months (range 12 – 14). Mean functional score at last follow-up was 15/9 compared with 13.5 preoperatively (paired test, p < 10–4) with 51 unions, 12 nonunions and 9 doubtful unions. Among the factors studied, trochanter fixation technique was the only factor predictive of outcome. Results were as follows for plate fixation alone: union 62%, doubtful union 13% and failure 25%. For hips with wire and plate fixation, the results were union 87.5%, doubtful union 12/5%, failure 0%. The difference was highly significant (chi-square, p = 0.006) in favour of wire-plate fixation of trochanteric fractures.

Discussion and conclusion: This study leads to the conclusion that the treatment of choice for trochanteric nonunion is wire-plate fixation which provides more than 90% good and very good results.

Purpose: The purpose of this retrospective study was to assess clinical and radiological outcome at ten years follow-up at least in a continuous series of total hip arthroplasties performed in patients with aseptic necrosis of the femoral head.

Material and methods: The series included 122 arthroplasties performed between January 1980 and December 1996 in 96 patients (26 women and 70 men), aged 50.8±13.3 years (range 21–85 years). The underlying cause was essential necrosis in 40.6%, cortocosteroid threapy in 19.8%, chronic alcoholism for 17%, trauma for 12%, and another medical cause for 10%. The Ficat and Arlet classification was grade IV 80 hips, grade III 42 hips. All arthroplasties were performed via the transtrochanteric approach. Cemented Charnley-Kerboull implants were used with a metal-polyethylene couple in all cases. The Merle d’Aubigné score was used to assess functional outcome. Cup wear was measured according to Livermore. Actuarial survival curves were calculated.

Results: Follow-up was greater than ten years for all patients (mean 13±2.6 years, range 10–21 years). At last follow-up 59 patients (75 hips) were living and had not undergone revision and seven patients (seven hips) had undergone revision of the acetabular and/or femoral component. Twenty patients (24 hips) had died and ten patients (16 hips) were lost to follow-up. Revision procedures were performed for periacetabular osteolysis in one hip, infection in one hip, and acetabular loosening in five hips. Three patients experienced luxation or subluxation. The mean preoperative function score was 11 (range 5 – 16) compared with 17 (14–18) at last follow-up (p < 0.05). Clinical outcome was good or excellent in 95% of the patients and fair or poor in 5%. Mean overall cup wear was 0.965 mm (0–5) for non revised hips. Lucent lines were found around eleven acetabular implants and six femoral implants. Cumulative survival, considering revision as failure, was 88.5% at 15 years (95% confidence interval 80.2 – 96.9%).

Discussion and conclusion: The results of this series lead to the conclusion that low-friction total hip arthroplasty is the treatment of choice for advanced stage femoral head necrosis.

Purpose: The cause of Paget’s disease, osteitis deformans, defined by increased bone resorption followed by excessive attempts at repair, remains unclear. The current hypothesis is that bone is slowly infected by paramyxovirus in genetically predisposed patients. We report the case of a patient with monostotic Paget’s disease of the pelvis which was transferred to the homolateral distal femur after total hip arthroplasty.

Case report: A 66-year-old man with Paget’s disease of the hemi-pelvis developed pagetic hip deformation requiring a total hip arthroplasty performed in 1993. A Charnley-Kerboull cemented prosthesis was implanted. The medullary canal was plugged with fragments of cancellous bone harvested from the acetabulum (drill holes required to achieve rotatory stability of the acetabulum). One year later, an asymptomatic osteolytic lesion of the distal femur was identified at the level of the medullary plug. Hip function remained excellent despite extension to the distal and proximal femur. All inflammatory parameters were normal and the femoral component was not loosened. 99m-technetium scintigraphy revealed strong uptake in the pelvis but also in the distal femur under the femoral stem. Isolated femoral stem revision was performed in 1996 as a preventive measure against stress fracture. Pathology analysis of surgical specimens identified Paget’s disease (osteoclast hyperactivity, mosaic aspect of the osteoblasts. After femoral revision with a long stem and medical treatment with biphosphonates, the osteolytic lesion disappeared progressively, taking on the classical sclerous sequelar aspect of osteitis deformans. The disease remained quiescent six years after revision. Hip function remained excellent at last follow-up.

Discussion and conclusion: This is the first report of this type of complication after total hip arthroplasty. This observation that Paget’s disease can be transferred via a autologous cancellous bone graft is in favour of the viral hypothesis, suggesting osteoclastic infection by contiguity. This complication has never been observed with frozen or radiated allograft material although such material may have been harvested from pathological bone, notably with Paget’s disease

Purpose: New surfaces have been developed to reduce polyethylene wear. The zircone ceramic surface appears to have a theoretical advantage due to its interesting tribologic properties. The purpose of this prospective study was to assess clinical and radiological outcome at a minimal two years follow-up in a consecutive series of total hip arthroplasties using the polyethylene zircone junction.

Material and methods: La series included 56 total hip arthroplasties performed in 49 patients (30 women and 19 men), mean age 52.2 ± 12 years (25–76). Primary degenerative hip disease was the aetiology in 43% of the cases, dysplasia in 27%. The femoral component was made of 316L steel with a 11°25 Morse cone for 27 hips and a 5°40 cone for 29 hips. The femoral head measured 22.2 mm and was made of polycrystaline zircone ceramic stabilised in the tragonal form with yttrium (Y-TZP). All the arthroplasties were performed via transtrochanteric access using cemented Charnley-Kerboull implants. Clinical outcome was assessed with the Merle-d’Aubigné score. Classical landmarks on the AP pelvis views were used to assess implant migration. Cup wear was measured using the Livermore method. Actuarial survival curves were plotted.

Results: Mean follow-up was 32 months (24–48). None of the patients were lost to follow-up. The mean functional score at last follow-up was 17.8±0.2 (16–18) versus 12.2±2.6 before arthroplasty (Student t test for paired variables, p < 0.0001). No cases of migration of the femoral or acetabular component were observed. Acetabular wear was always less than the precision of the measurement method. Osteolytic lesions were however observed as endosteal defects in the Merkel region measuring less than 1 cm2, observed in 18 out of the 56 hips (32%). These osteolytic lesions generally appeared between the first and second year and did not appear to progress.

Discussion: Osteolysis in the Merkel region appeared early for one third of the hips, despite the absence of cup polyethylene wear. It would be reasonable to be prudent when using zirone ceramic heads. We are continuing our close follow-up of this group of patients. In addition, measurements of wear and migration are being made using the EBRA method.

We have carried out a prospective, randomised study designed to compare the long-term stability of the stem of cementless femoral implants with differing surface configurations. A total of 50 hips (46 patients) was randomised into two groups, according to whether the medullary stem had been grit blasted (GB) or coated with hydroxyapatite (HA). Both femoral prostheses were of the same geometrical design. We used Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) to assess the stability of the stem. The mean follow-up was for 8.66 years.

The mean migration of the stem was 1.26 mm in the HA group compared with 2.57 mm in the GB group (Mann-Whitney U test, p = 0.04). A mixed model ANOVA showed that the development of subsidence was statistically different in the two groups during the first 24 months. After this subsidence increased in both groups with no difference between them. Our results indicate that, with the same design of stem, HA coating enhanced the stability of the femoral stem when compared with GB stems.

We compared and quantified the modes of failure and patterns of wear of 11 Mittelmeier and 11 Ceraver-Ostal retrieved alumina-alumina hip prostheses with reference to the corresponding clinical and radiological histories.

Macroscopic wear was assessed using a three-dimensional co-ordinate measuring machine. Talysurf contacting profilometry was used to measure surface roughness on a microscopic scale and SEM to determine mechanisms of wear at the submicron level.

The components were classified into one of three categories of wear: low (no visible/measurable wear), stripe (elliptical wear stripe on the heads and larger worn areas on the cups) and severe (macroscopic wear, large volumes of material lost). Overall, the volumetric wear of the alumina-alumina prostheses was substantially less than the widely used metal and ceramic-on-polyethylene combinations. By identifying and eliminating the factors which accelerate wear, it is expected that the lifetime of these devices can be further increased.