Radiolucencies are generally thought to be a manifestation of loosening. They are commonly seen under the tibial component of the Oxford Unicompartmental knee replacement. However, they are not associated with long term failure [. 1. ]. The aim of this study was to investigate any relationship between radiolucencies and component migration. Eight medial Oxford Unicompartmental knee prostheses were examined post-operatively, at 12 months and at 24 months using Roentgen Stereophotogrammetric Analysis (RSA). The serial radiographs were calibrated and three dimensional CAD models were matched to the extracted component shapes. Implanted bone marker balls were then selected on all radiographs. The components were superimposed. Migration calculation was achieved by comparing relative positions of components to bone marker balls in the serial radiographs. Fluoroscopically screened X-rays were taken to determine whether there were any radiolu-cencies under the tibial component. By 12 months, the femoral component had migrated significantly anteriorly (0.35 mm) and proximally (0.61 mm). The tibial component had migrated significantly distally (0.42 mm) and anteriorly (0.47 mm). Although on average there appeared to be a small further migration between 12 and 24 months, this was not statistically significant in any direction. Six of the eight patients had radiolucencies at 24 months. None of the radiolucencies were was complete. The maximum radiolucency was 1 mm thick and the average was 0.57 mm. There was no correlation between radiolucency and migration. The proximal femoral migration and distal tibial migration can be explained by the load across the knee. We cannot yet explain the anterior tibial migration. Radiolucencies almost always occur and are not related to migration.This confirms they are not associated with loosening

Introduction: Partial Knee Replacement (PKR) is an appealing alternative to Total Knee Replacement (TKR) when the patient has isolated compartment osteoarthritis (OA). In nearly all cases there is a radiolucency observed between the tibial tray wall and the boney interface. The reasons why radiolucencies appear are unknown, but the bone will adapt to its altered mechanical environment by bone remodelling in accordance with ‘Wollf’s Law’. The aim of this study was to investigate the mechanical environment of the tibia bone adjacent to the tray wall, following cemented and cementless PKR, in order to determine whether this region of bone resorbs.

Methods: A validated finite element (FE) model of a cadaver tibia implanted with an Oxford PKR was used in this study. Kinematic data from fluoroscopy measurements during a step-up activity were used to determine the relative tibio-femoral positioning for the Oxford PKR model. Load data were adapted from the in-vivo measured loads using an instrumented implant during a step-up activity. The standard operating protocol was simulated for the Oxford PKR FE models, with the tibial tray implanted in a neutral position. The tibia was sectioned around the tray. Zone 7 was defined as parallel to the vertical tray wall, corresponding to the region on screened x-rays where radiolucencies are observed. It was assumed that the bone in the implanted tibia will attempt to normalise its stress-strain patterns locally to its equilibrium state, the intact tibia, for the same loading conditions. Forty patients (20 cemented, 20 cementless) who had undergone PKR were randomly selected from a database, and their screened x-rays assessed for radiolucency in region 7.

Results: The SED in region 7 was 80% lower in the cemented and cementless tibia, compared to the intact tibia (Figure 2). The maximum tensile stress was 63% lower in the cemented and cementless tibia, compared to the intact tibia. The corresponding maximum compressive stress was 52% lower. Radiolucency was observed in all forty radiographs in region 7.

Discussion: After implantation with a cemented or cementless PKR the bone strains and SED in region 7 are reduced. This reduction may provide the signal for adaptive bone remodelling and bone will be resorbed from this region, decreasing the volume and increasing the SED. Bone resorption will continue until the equilibrium state is reached. If a ‘lazy’ zone between 35% and 50% of the remodelling signal is considered, bone resorption will still occur due to the large decrease in SED for this region. For region 7 to return its SED to the equilibrium state, its volume will need to be reduced by 80%. This is likely to be the reason why a radiolucency is observed clinically in this region in almost every case, whether a cemented or cementless implant is used.

Introduction

Cementless fixation is the current preferred method for acetabular reconstruction in total hip arthroplasty (THA). Despite promising long-term results among several designs, theoretic concerns regarding the high modulus of elasticity, low friction against bone and low volumetric porosity of contemporary cementless cups have spurred the introduction of novel porous surfaces that are designed to improve osseointegration and decrease aseptic loosening. Although several novel surfaces have been introduced into clinical use over the past decade, very little literature regarding their clinical and radiographic performance exists. The current study investigates the performance of one such novel surface, Tritanium (Stryker, Mahwah, NJ).

Introduction

Unicompartmental Knee Replacement (UKR) is an appealing alternative to Total Knee Replacement (TKR) when the patient has isolated compartment osteoarthritis (OA). A common observation post-operatively is radiolucency between the tibial tray wall and the bone. In addition, some patients complain of persistent pain following implantation with a UKR; this may be related to elevated bone strains in the tibia. The aim of this study was to investigate the mechanical environment of the tibia bone adjacent to the tray wall, following UKR, to determine whether this region of bone resorbs, and how altering the mechanical environment affects tibia strains.

Aims. The primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs). Methods. A single blinded randomized, non-inferiority study was conducted including 74 patients. Radiostereometry examinations were made after weight bearing, but before hospital discharge, and at three, six, 12, and 24 months postoperatively. PROMS were collected preoperatively and at three, six, 12, and 24 months postoperatively. Radiographs for measuring radiolucencies were collected at two weeks and two years postoperatively. Results. The overall migration (mean maximum total point motion (MPTM)) at two years was comparable: mean 1.13 mm (95% confidence interval (CI), 0.97 to 1.30) for the ATTUNE and 1.16 mm (95% CI, 0.99 to 1.35) for the PFC-sigma. At two years, the mean backward tilting was -0.43° (95% CI, -0.65 to -0.21) for the ATTUNE and 0.08° (95% CI -0.16 to 0.31), for the PFC-sigma. Overall migration between the first and second postoperative year was negligible for both components. The clinical outcomes and PROMs improved compared with preoperative scores and were not different between groups. Radiolucencies at the implant-cement interface were mainly seen below the medial baseplate: 17% in the ATTUNE and 3% in the PFC-sigma at two weeks, and at two years 42% and 9% respectively (p = 0.001). Conclusion. In the first two postoperative years the initial version of the ATTUNE tibial component was not inferior with respect to overall migration, although it showed relatively more backwards tilting and radiolucent lines at the implant-cement interface than the PFC-sigma. The version of the ATTUNE tibial component examined in this study has subsequently undergone modification by the manufacturer. Level of Evidence: 1 (randomized controlled clinical trial). Cite this article: Bone Joint J 2020;102-B(9):1158–1166

Background. Hip resurfacing arthoplasty (HRA) showed promising early and mid-terms results at the beginning of the new millennium. Adverse local tissue reactions associated with metal debris considerably slowed down the implantation of HRA which use is now limited to a few specialized centers. The long term success of this procedure, however, is still largely unknown. This study aimed to provide the clinical results of a series of 400 consecutive HRA with a minimum follow-up of 20 years. Methods. All patients treated with Conserve. ®. Plus HRA between November 1996 and November 2000 were retrospectively selected and 355 patients (400 hips) were included. The clinical results of this series was previously reported in 2004 at a follow up of 2 to 6 years[1]. There were 96 women (27%) and 259 men (73%). Mean age at surgery was 48.2 ± 10.9 years. Long-term survivorship was assessed with Kaplan-Meier survival estimates. UCLA hip scores and SF-12 quality of life scores were collected at follow-up visits. Radiographic positioning of the acetabular component was assessed with the computation of the contact patch to rim (CPR) distance. Radiolucencies about the metaphyseal stem and around the acetabular component were recorded to assess the quality of the component fixation. Results. The mean time of follow up was 16.3 ± 5.5 years including 183 hips beyond 20 yrs. Nine hips were lost to follow up (2.2%) Thirty-three patients (35 hips,8.8%) died of causes unrelated to the surgery at a mean 11.9 ± 5.3 years after surgery The mean UCLA hip scores at last follow-up were 9.3 ± 1.0, 9.1 ± 1.4, 9.0 ± 1.8, and 6.9 ± 1.7 for pain, walking, function, and activity, respectively. Post-operative SF-12 scores were 48.4 ± 10.3 for the physical component and 48.5 ± 15.5 for the mental component and did not differ from those of the general US population. Fifty-five patients (60 hips) underwent revision surgery at a mean time of 9.3 ± 5.8 years. Indications for revision surgery included acetabular component loosening (12 hips), femoral component loosening (31 hips), femoral neck fracture (6 hips), wear (6 hips), sepsis (2 hips), recurrent dislocations (1 hip), acetabular component protrusion after over-reaming (1 hip) and unknown (1 hip which was revised in another center). Using any revision as an endpoint, the Kaplan-Meier survivorship was 95.2% at 5 years, 91.2% at 10 years, 87.3% at 15 years, and 83.2% at 20 years. A multivariate model for risk factor analysis showed a diagnosis of developmental dysplasia (p=0.020) and a low body mass index (typically associated with higher levels of activity) (p=0.032), to be significantly related to revision for any reason. Female sex was not a risk factor after adjustment for hip dysplasia and component size was made (Table 1). There was only 1 femoral failure (a late neck fracture 19 years after surgery) among the hips reconstructed with a cemented metaphyseal stem (n=59). Five of the 6 hips (1.5%) with wear-related failures all had mal-positioned sockets (CPR distance <10mm) and were therefore preventable. There were no cases with a high score of aseptic lymphocytic vasculitis-associated lesions (ALVAL)[2], suggesting metal sensitivity. X-ray analysis showed excellent persisting fixation in all but one hip. Conclusions. In this group of patients operated over 20 years ago, HRA keeps providing excellent pain relief and quality of life to the patients. Subsequent progress in the preparation of the femoral head has considerably reduced the failure rate on the femoral side which was the main mode of failure in this initial series[3, 4]. The 83.1% 20 year survivorship of this initial series surpasses that of total hip arthroplasties in use 20 years ago in this young patient population[5]. Life-long durability of the device is anticipated for most of the remaining patients. The established benefits of this procedure, such as a low dislocation rate, an anatomic reconstruction with physiologic loading of the proximal femur, the absence of taper corrosion, and an easy conversion if ever necessary, make HRA a preferable alternative to THA in young and active patients. For any figures, tables, or references, please contact the authors directly

Introduction. Modularity in femoral stem designs allow surgeons to independently control leg length, offset, and femoral version in revision or complex primary THA cases. Initial enthusiasm in these modular stems has been tempered by recognition of modular junction failures. This study evaluates mean 5-year clinical results and survival rates of a 3-part titanium alloy modular femoral implant with unique taper geometries and a metaphyseal plasma spray surface. The current results are presented after pre-market independent fatigue testing performed by Orthopaedic Laboratory (Greenwald) and previously published early clinical results in 2006. Low plasticity burnishing (LPB) was added in 2005 to further strengthen the neck metaphyseal modular junction. The modular stem component is a polished cylindrical splined clothespin design. Our hypothesis is that these unique modular junctions succeed in offering the advantages of modularity without failure at this midterm follow-up period. Methods. Between May 2010 and July 2016, 32 total hip arthroplasties were performed using a 3-part femoral stem with neck-metaphyseal-stem modular junctions. Surgeries were either the final stage of a two-stage revision for infection, revision THR for loosening, or a revision of a previous non-prosthetic replacement procedure. Patients were entered into an IRB-approved registry and followed with x-rays, HHS, Oxford scores, and patient satisfaction scores. Patients who failed to return for routine follow-up were contacted by phone or email. Two patients had died with their implants intact. Six patients could not be reached for an updated follow-up. One stem was revised for loosening at 33 months due to failed osseointegration in a patient with chronic renal failure. This removed stem was submitted for taper exam and sectioning. Results. There were 23 patients for evaluation at a mean 61 months (range 21–98). Mean patient age at implantation was 56 (range 25–88), BMI was 27 (range 20–40). There were no modular junction failures. Modular junctions examined in the retrieved implant did not demonstrate any abnormalities other than normal wear properties. HHS and OHS scores both improved between pre-op and final follow-up, 23 to 85 and 17 to 43, respectively. Average patient satisfaction score at final follow-up was 9.8 out of 10 (min 8, max 10). Radiographic examination showed stem subsidence > 2mm and radiolucencies around the metaphyseal cone in 1 patient, the same patient who required implant removal. Radiolucencies were seen along the polished stem tip in 43% of cases, spot welding at the distal metaphyseal cone in 67% of cases, and mild proximal-medial stress shielding in 33% of cases. Conclusion. This unique 3-part modular stem with metaphyseal fixation shows good functional and radiographic results at 5-year follow-up. There were no junctional failures. One stem was removed due to failure to osseointegrate and showed no worrisome taper abnormalities. Spot welding is common around the plasma spray metaphyseal cone. Implant removal, if necessary, only requires disruption of the metaphyseal fixation. Further follow-up will be important to confirm our confidence in this unique stem design

Aims

The purpose of this study is to report our updated results at a minimum follow-up of 30 years using a first generation uncemented tapered femoral component in primary total hip arthroplasty (THA).

To report mid-term results of PJI treated with uncemented stems. : 80 hips of PJI after THA were treated with uncemented stems from 01/1993 to 12/2012 and followed prospectively. Selection occurred for one- (n=27) or two-stage (n=53) exchange according to the Liestal algorithm. Surgical approaches were transfemoral (n=58), transgluteal (n=9) or transtrochanteric (n=13). A monoblock (Wagner SL, n=58) or modular (Revitan, n=22) revision stem was implanted. On the acetabular side 44 Müller rings, 33 Burch-Schneider cages (combined with a cemented PE-cup) and 3 press-fit cups were used. Kaplan-Meier survival was calculated for endpoints (a) persistence of infection, (b) septic/aseptic stem loosening. Radiographs were analysed for (a) subsidence, (b) distal stem integration, (c) changes in cortical thickness, (d) proximal femur restoration, (e) radiolucency around stem/cup. Mean FU was 5.2 (2–15) years. PJI was eradicated in 77 of 80 hips (96%). 3 patients (all two-stage) had a treatment failure. 2 were treated successfully with an additional two-stage exchange. In the 3rd patient we were not able to control infection and exarticulation was performed. Furthermore, one stem was revised for aseptic loosening (5 years), 1 for a broken Wagner stem (7 years) and 1 for subsidence (8 months). Stem survival after 5 years was 93% (SD ±2.5 years). 2 cups were revised for aseptic loosening and 1 for recurrent dislocations. Subsidence ≥5mm was found in 6 hips and occurred always within 3 months after surgery independent of stem type (p=0.947) and approach (p=0.691). Proximal femoral remodelling after transfemoral approach was excellent or good in 71% (32 excellent, 9 good) with no difference between one-/two-stage exchanges (p=0.288). Initial distal stem integration was 65mm medial and 66mm lateral and increased to 8mm medial (p=0.716) and 10mm lateral (p<0.001). Cortical thickness was unchanged over the entire FU period (p=0.493). Radiolucencies were seen around 26 stems, only the stem revised after 5years was rated loose. Eradication of PJI was high using our established protocol even with uncemented revision stems. Mid-term survival was independent from one-/two-stage revision and comparable to results for aseptic loosening revision

144 total hip replacements were performed by Swedish Orthopaedic Surgeons at Weston NHS Treatment Centre between 2004–2006, in an attempt to reduce the waiting list in Cardiff. Following concerns regarding the outcome of knee arthroplasty patients, the Welsh Assembly funded a clinical and radiographic review of all hip arthroplasty patients from the same unit. 100 hips were reviewed at a mean follow-up of 24 months. The mean Oxford Hip Score was 30 (range 12–60). Radiolucencies were seen in acetabular zone 1 in 34, and all 3 zones in 28 hips. Femoral component position was > 4 degrees varus in 41 cases. Medial floor breach with intrapelvic cement was seen in 12 cases. 10 cases had > 1cm leg length discrepancy. There were 3 early dislocations, 1 intraoperative distal femoral fracture, 1 Pulmonary Embolus and 2 superficial infections. 4 patients have received further treatment so far, and 12 have been listed for acetabular component revision for loosening. 1 has been listed for stem revision for symptomatic leg length discrepancy of 2.5cm. There is an unacceptably high early failure rate in this group of patients. The cost of further investigation and revision surgery far outweighs cost-savings achieved by outsourcing treatment to a distant centre

Introduction. Up to date there are only few reports in literature on the long term survival of uncemented stems. As for cemented THA, 10 year survival of at least 90% is required for any THA. Materials and methods. We followed the first 354 consecutive implantations of an uncemented, straight femoral stem (CLS, Zimmer Inc, Warsaw, USA) in 326 patients. Mean time of follow-up evaluation was 17 years (range, 15-20 years). Results. At follow-up, 84 patients (88 hips) had died, and 12 (12 hips) were lost to follow-up. 34 hips underwent femoral revision: 8 for infection, 8 for periprosthetic fracture, 1 for traumatic loosening and 17 for aseptic loosening of the stem. Overall survival was 89% at 17 years (95%-confidence limits, 87%-92%), survival with femoral revision for aseptic loosening as an end point was 94% at 17 years (95%-confidence limits, 92%-95%). The mean Harris Hip Score at follow-up was 83 points. 220 hips were available for radiolographic evaluation. None of the femoral components showed signs of loosening. Radiolucent lines (<2mm) in Gruen zones 1 and 7 were present in 14.1% (31 hips) and 15.0% (33 hips) respectively. Radiolucencies in zones 2-6 were found in 0.5% (1 hip)-1,8% (4 hips) on ap x-rays. Only one case of distal osteolysis was found after a previous Wagner resurfacing. No case of severe femoral osteolysis was found. The only strong predictor for aseptic loosening was undersizing of the stem with a canal fill index of <75%. Conclusions. The long-term results for this uncemented stem are encouraging and compare favorably with those achieved in primary cemented total hip arthroplasty in this age group

Between 1990–92, 59 Primary TKA’s were performed in 55 Patients with a mean follow-up of 9 years (8–10). Mean age at review was 75 years (61–87). Materials and Method: All cementless TKA’s (Whiteside Ortholoc Modular 3). One surgeon (operating or supervising). Intramedullary guides(tibia and femur). Lateral retinacular release. Clinical evaluation according to the Knee Society Scoring System & Knee Society TKA Roentgenographic Evaluation and Scoring System. Median Knee Score 93.5 (41–97). Median Functional Score 77.5 (35–100). Median flexion 100 degrees (80–120). All but one knee came to full extension. No effusions or swellings. Radiolucencies in one TKA only. Discussion: Long term success of TKA’s (cementless or cemented) depends on correct alignment of the implants. Rigidity of fixation is the second most important feature in achieving pain free function in an arthroplasty. Success in this series was due to good alignment of components. Good alignment minimises polyethelene wear. Rigid tibial fixation prevents motion, tilting and malalignment reducing wear

Aims: As part of the guidelines recommended by NICE (National Institute of Clinical Excellent), we are presenting the early results of this new hip replacement component. Methods: We reviewed 65 consecutive primary total hip replacements in 59 patients in which the Opera Flanged cemented acetabular component (smith & nephew) had been used. The mean follow-up was 47 months (36 to 63). In all cases a Charnley femoral prosthesis had been used. There were 39 women and 26 men with a mean age at operation of 67.4 years (33 to 90). Survival analysis of the acetabular components was performed. Results: Two components were revised due to deep infection, and one of these cups was discovered to be well fixed at operation. None of the acetabular components required revision for aseptic loosening. After 5 years survival was 97% using the worst-case scenario. Radiological analysis of all acetabular components at 12 months post-operation and at yearly intervals revealed no cases of aseptic loosening. Radiolucencies around the cemented socket were noted in five patients, but were not progressive on sequential radiographs. Conclusions: The early results are encouraging and the follow-up will be continued to assess the 10 years results

Introduction: THA in young and active patients remains a major challenge. Uncemented femoral components have been advocated in young patients, but there are only few reports with more than 10 years follow-up. Materials and Methods: We followed the first 153 consecutive implantations of an uncemented, straight femoral stem (CLS, Zimmer Inc, Warsaw, USA) in 141 patients. Mean time of follow-up evaluation was 17 years (range, 15–20 years), mean age at surgery was 47 years (23–55). Results: At follow-up, 20 patients (20 hips) had died, and 7 (7 hips) were lost to follow-up. 10 patients (10 hips) underwent femoral revision–1 for infection, 4 for periprosthetic fracture, and 5 for aseptic loosening of the stem. Overall survival was 91% at 17 years (95%-confidence limits, 88%-94%), survival with femoral revision for aseptic loosening as an end point was 95% (95%-confidence limits, 93%–98%). The mean Harris-Hip-Score at follow-up evaluation was 84 points. 116 hips were available for radiolographic evaluation. Radiolucent lines (< 2mm) in Gruen zones 1 and 7 were present in 12,9% (15 hips) and 13,8% (16 hips), respectively. Radiolucencies in zones 2–6 were found in 0,9% (1 hip) – 2,6% (3 hips) on ap x-rays. Only one case of distal osteolysis was found after a previous Wagner resurfacing. No case of severe femoral osteolysis was found at follow-up. Conclusions: The long-term results with this type of uncemented femoral component are encouraging and compare favorably with those achieved in primary cemented total hip arthroplasty in this group of young and active patients

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

Introduction: THA in young and active patients remains a major challenge. Uncemented femoral components have been advocated in young patients, but there are only few reports with more than 10 years follow-up. Materials and Methods: We followed the first 153 consecutive implantations of an uncemented, straight femoral stem (CLS, Zimmer Inc, Warsaw, USA) in 141 patients. Mean time of follow-up evaluation was 17 years (range, 15 – 20 years), mean age at surgery was 47 years (23–55). Results: At follow-up, 20 patients (20 hips) had died, and 7 (7 hips) were lost to follow-up. 10 patients (10 hips) underwent femoral revision- 1 for infection, 4 for periprosthetic fracture, and 5 for aseptic loosening of the stem. Overall survival was 91% at 17 years (95%-confidence limits, 88%–94%), survival with femoral revision for aseptic loosening as an end point was 95% (95%-confidence limits, 93% – 98%). The mean Harris-Hip-Score at follow-up evaluation was 84 points. 116 hips were available for radiolographic evaluation. Radiolucent lines (< 2mm) in Gruen zones 1 and 7 were present in 12,9% (15 hips) and 13,8% (16 hips), respectively. Radiolucencies in zones 2 – 6 were found in 0,9% (1 hip) – 2,6% (3 hips) on ap x-rays. Only one case of distal osteolysis was found after a previous Wagner resurfacing. No case of severe femoral osteolysis was found at follow-up. Conclusions: The long-term results with this type of uncemented femoral component are encouraging and compare favorably with those achieved in primary cemented total hip arthroplasty in this group of young and active patients

Aims: To investigate the cup interface with different means of þxation. Methods: 83 patients (89 hips) (median age of 56 years) were operated with a uncemented hemispherical porous-coated cup made of titanium alloy (Reßection, Smith & Nephew¨) with pressþt technique. The patients were randomised to pressþt-only (PF), PF + Hydroxyapatite (PF+HA), PF + 3 screws (PF+S) and PF + 3 pegs (PF+P). The development of radiolucent lines in percentage of circumference was evaluated on x-ray þlms postoperative and at two years. Radiostereometry was used for migration and wear measurement. Results: All cups were stable after 2 years. The groups showed no signiþcant difference in migration. Radiolucencies were found in a mean of 20% of interface in PF+S, 14% in PF+P, 11% in PF and 0% in PF+HA (P = 0.005, Kruskall Wallis test). 5 focal osteolysis were found in PF+S, 1 in PF+HA and PF and none in PF+P (ns). 35 cups had a gap between the central part of the cup and acetabulum postoperatively (no differences between groups). After 2 years the gaps in the HA group had disappeared. Cup wear was highest for HA coated cups. Conclusions: Further studies are necessary to reveal whether the better implant bone interface will outweigh the risk for increased wear

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

Aims: description of results obtained with a single radius TKA design. Matherials and methods: In 1999 we started implanting single-radius TKA design (Scorpio–Osteonics). Between January 1999 and April 2002 we have implanted 211 TKA, 15 bilateral, with 24 months average follow-up (range 3–36 months). This type of prosthesis is based on the concept that the normal knee rotates about a single axis – the transepicondylar axis. This reduces mid-flexion instability, improves patello-femoral tracking and decreases the occurrence of anterior knee pain. Results: Knee Society score has improved to 90 points post-op from 39 points pre-op and function evaluation from 44 to 82 points. We had 128 cases excellent (65.6%), 40 good (20.5%), 24 fair (12.4%) and 3 poor (1.5%). X-ray follow-ups have revealed in 83% of cases knee angulation between 2° from neutral, in 11% a varus deviation between 3° and 5° and in 6% a valgus deviation between 3° and 5°. Radiolucencies have been found in 18 patients (9.23%). Conclusions: Scorpio single-radius prosthesis has permitted a full and early recovery of knee function. Bone cuts, especially the tibial one, are reduced. Anterior knee pain is dramatically reduced and is associated with incremented range of motion and improvement in knee stability, especially in the mid flexion. These short term results are really encouraging, but need to be confirmed by future follow-up studies