Aims

Bone stock restoration of acetabular bone defects using impaction bone grafting (IBG) in total hip arthroplasty may facilitate future re-revision in the event of failure of the reconstruction. We hypothesized that the acetabular bone defect during re-revision surgery after IBG was smaller than during the previous revision surgery. The clinical and radiological results of re-revisions with repeated use of IBG were also analyzed.

Introduction

Total hip arthroplasty (THA) dislocation has been associated with different risk factors. The main difficulty in analysing dislocation is its low rate of incidence, necessitating large series for study.

We assessed factors related with patients, implant characteristics, and quality of the hip reconstruction to better identify their influence on the THA dislocation rate.

Introduction

Pelvic tilt can vary over time due to aging and the possible appearance of sagittal spine disorders. Cup position in total hip arthroplasty (THA) can be influenced due to these changes. We assessed the evolution of pelvic tilt and cup position after THA and the possible appearance of complications for a minimum follow-up of ten years.

Introduction

Biological repair of acetabular bone defects after impaction bone grafting (IBG) in total hip arthroplasty could facilitate future re-revisions in case of failure of the reconstruction again using the same technique. Few studies have analysed the outcome of these acetabular re-revisions.

Introduction

Although pelvic tilt does not significantly change after primary total hip arthroplasty (THA) at a short term, can vary over time due to aging and the possible appearence of sagittal spine disorders. Cup positioning relative to the stem can be influenced due to these changes.

Background

Aseptic loosening is rare with most cementless tapered stems in primary total hip arthroplasty (THA), however different factors can modify results. We ask if the shape and technique of three current different femoral components affects the clinical and radiological outcome after a minimum follow-up of ten years.

Introduction

Impaction bone grafting (IBG) is a reliable technique for acetabular revision surgery with large segmental defects. However, bone graft resorption and cup migration are some of the limitations of this tecnique. We assess frequency and outcome of these complications in a large acetabular IBG series.

Introduction

Durable bone fixation of uncemented porous-coated acetabular cups can be observed at a long-term, however, polyethylene (PE) wear and osteolysis may affect survivorship. Accurate wear measurements correlated with clinical data may offer unique research information of clinical interest about this highly debated issue.

Introduction

Durable bone fixation of uncemented porous-coated acetabular cups can be observed at a long-term, however, polyethylene (PE) wear and osteolysis may affect survivorship. Accurate wear measurements correlated with clinical data may offer unique research information of clinical interest about this highly debated issue.

Introduction

Acetabular fractures management is controversial since, despite a good anatomical reduction, clinical outcome is not satisfactory very often and the probability of a total hip arthroplasty (THA) is high. Surgical treatment include long operating times, large approach, blood loss, neural and muscle damage, and a high risk of failure and secondary osteoarthritis related to bone necrosis, cartilage damage, and bone loss.

We hypothesized that the acetabular fracture management affected the clinical and radiological outcome of THA after posttraumatic arthritis.

Introduction

Implantation of total hip replacement (THR) remains a concern in patients with developmental dysplasia of the hip (DDH) because of bone deformities and previous surgeries. In this frequently young population, anatomical reconstruction of the hip rotation centre is particularly challenging in severe, low and high dislocation, DDH. The basic principles of the technique and the implant selection may affect the long-term results.

The aim of the study was to compare surgical difficulties and outcome in patients who underwent THR due to arthritis secondary to moderate or severe DDH.

Different pathologies, deformities, bone defects, previous surgeries and polyethylene wear limit the survival of total hip arthroplasty (THA) in young patients. We compare preoperative status and outcome in 171 young and very young patients (207 hips) who underwent a ceramic-on-ceramic THA. Sixty-three (77 hips) were less than 30 years old (group 1) and 108 (130) were between 30 and 40 years old. Mean follow-up was 11.3 years. Two-way ANOVA with repeated measures were used to analyse clinical and radiological changes.

Juvenile rheumatoid arthritis (JRA) was the most frequent diagnosis in group 1 and avascular necrosis in group 2. Charnley class type C, low activivity, previous surgery and osteoporotic bone were more frequent in group 1 patients. There were 2 cup revisions for aseptic loosening in group 1 and 4 in group 2. Survivorship analysis at 15 years was 96.7% (95% IC 92.2 a 100) for group 1 and 96.1% (95% IC 92.2 to 100) for group 2 (p=0.749). Despite the worse preoperative status in group 1 patients, clinical outcome was similar in both groups. Severe dysplasia had the worst clinical result and avascular necrosis the best. Patients with Charnley class C and JRA showed the most improvement. Radiographic reconstruction of the abduction angle was worse in group 1 (p=0.02). No osteolysis or complications derived from ceramic use were found.

We conclude that despite the worse preoperative status in group 1 patients, clinical and radiographic results were good in both groups of patients who received a ceramic-on-ceramic THA.

Background and aim

Despite good survivorship analysis for most uncemented tapered straight stems, new proposals modifying stem design in total hip replacement (THR) are being introduced in order to facilitate femoral revision surgery.

We have evaluated the clinical and radiological results of four different designs of uncemented tapered straight stems implanted in our institution in order to assess: operative complications, clinical results, survivorship analysis for aseptic loosening and radiographic findings

Background and aim

A significant reduction in wear using Durasul highly cross-linked polyethylene (PE) versus Sulene polyethylene (sterilized with nitrogen) at 5 and 10 years have been reported previously. We ask if the improvement observed at the earlier follow-up continues at 15 years.

Background and aim

Total hip replacement (THR) in young patients has been associated to higher revision rates than in older population. Different conditions may lead to end-stage arthritis of the hip in these patients.

We compared the clinical and radiological outcome of two different groups of young and very young patients who underwent a ceramic-on-ceramic THR.

Introduction

Alumina-on-alumina in total hip replacement has been used for avoiding osteolysis and loosening. Published series report no ceramic wear and low rates for fractures and noises, but report poor results because of acetabular fixation failure. From 1999 to 2005, we used the “first generation” of a cementless cup, tri-radius relatively-smoothed HA coated (group 1), and from 2006 we have used a “second-generation” of this same cementless cup design with a macrotextured surface (group 2). We compare the perioperative conditions of two groups of patients using these two different cups and the clinical and radiological results.

Background and aim

Recent proposals have been introduced to modify stem design and/or femoral fixation in total hip replacement (THR). New designs need to consider previous design features and their results. The aim of this study has been to evaluate the clinical and radiological results of six different designs of tapered uncemented stems implanted in our Institution.

Introduction

The use of screws is frequent for additional fixation, however, since some disadvantages have been reported a cup press-fit is desirable, although this can not always be obtained. Cup primary intraoperative fixation in uncemented total hip replacement (THR) depends on sex, acetabular shape, and surgical technique. We analyzed different factors related to primary bone fixation of five different designs in patients only diagnosed with osteoarthritis, excluding severe congenital hip disease and inflammatory arthritis, and their clinical and radiological outcome.

Although cemented fixation provides excellent results in primary total hip replacement (THR), particularly in patients older than 75 years, uncemented implants are most commonly used nowadays. We compare the rate of complications, clinical and radiological results of three different designs over 75-years-old patients.

Introduction

Uncemented press-fit cups provide bone fixation in primary total hip replacement (THR). However, sometimes screws are needed to achieve primary stability of the socket. We analyzed biomechanical factors related to press-fit in seven cup designs and assessed whether screw use provides similar loosening rates to those of the press-fit technique.

Background

Cup migration and bone graft resorption are some of the limitations after acetabular impaction bone grafting (IBG) technique in revision hip surgery when used for large segmental defects. We asked whether the use of a metallic mesh may decrease the appearance of this complication. We compared the appearance of loosening in patients with a bone defect 3A or 3B according to Paprosky.

Introduction

Dislocation is one of the most important complications after primary total hip replacement (THR). The low incidence of this finding makes it difficult to analyse the possible risk factors. The surgical technique can also influence this rate through cup position or an adequate reconstruction of the hip.

We assessed the demographic data and radiological reconstruction of the hip related to the appearance of dislocation after primary THR.

A total of 31 patients, (20 women, 11 men; mean age 62.5 years old; 23 to 81), who underwent conversion of a Girdlestone resection-arthroplasty (RA) to a total hip replacement (THR) were compared with 93 patients, (60 women, 33 men; mean age 63.4 years old; 20 to 89), who had revision THR surgery for aseptic loosening in a retrospective matched case-control study. Age, gender and the extent of the pre-operative bone defect were similar in all patients. Mean follow-up was 9.3 years (5 to 18).

Pre-operative function and range of movement were better in the control group (p = 0.01 and 0.003, respectively) and pre-operative leg length discrepancy (LLD) was greater in the RA group (p < 0.001). The post-operative clinical outcome was similar in both groups except for mean post-operative LLD, which was greater in the study group (p = 0.003). There was a significant interaction effect for LLD in the study group (p < 0.001). A two-way analysis of variance showed that clinical outcome depended on patient age (patients older than 70 years old had worse pre-operative pain, p = 0.017) or bone defect (patients with a large acetabular bone defect had higher LLD, p = 0.006, worse post-operative function p = 0.009 and range of movement, p = 0.005), irrespective of the group.

Despite major acetabular and femoral bone defects requiring complex surgical reconstruction techniques, THR after RA shows a clinical outcome similar to those obtained in aseptic revision surgery for hips with similar sized bone defects.

Cite this article: Bone Joint J 2014;96-B:1478–84.

We report the results of 79 patients (81 hips) who underwent impaction grafting at revision hip replacement using the Exeter femoral stem. Their mean age was 64 years (31 to 83). According to the Endoklinik classification, 20 hips had a type 2 bone defect, 40 had type 3, and 21 had type 4. The mean follow-up for unrevised stems was 10.4 years (5 to 17).

There were 12 re-operations due to intra- and post-operative fractures, infection (one hip) and aseptic loosening (one hip). All re-operations affected type 3 (6 hips) and 4 (6 hips) bone defects. The survival rate for re-operation for any cause was 100% for type 2, 81.2% (95% confidence interval (CI) 67.1 to 95.3) for type 3, and 70.8% (95% CI 51.1 to 90.5) for type 4 defects at 14 years. The survival rate with further revision for aseptic loosening as the end point was 98.6% (95% CI 95.8 to 100). The final clinical score was higher for patients with type 2 bone defects than type 4 regarding pain, function and range of movement. Limp was most frequent in the type 4 group (p < 0.001). The mean subsidence of the stem was 2.3 mm (sd 3.7) for hips with a type 2 defect, 4.3 mm (sd 7.2) for type 3 and 9.6 mm (sd 10.8) for type 4 (p = 0.022).

The impacted bone grafting technique has good clinical results in femoral revision. However, major bone defects affect clinical outcome and also result in more operative complications.

Introduction: Severe stress shielding and radiographic cortical changes in the proximal femur are frequent after extensively porous-coated stem in revision surgery. We have analyzed the evolution of the femoral cortex at different levels and related factors.

Material and Methods: We assessed 95 extensively porous-coated stems in revision surgery with a minimum 5-year follow-up (Mean 10.2 years). 77 hips were revised due to aseptic loosening and 18 due to periprosthetic fractures. Extended osteotomy was used in 29 hips. No cortical struts were used. Preoperative and postoperative osteoporosis was graded according to Moreland and bone defect according to Paprosky. Femoral cortex width was measured at different levels in the immediate postoperative radiograph, at 3, 6 and 12 months and at the last follow-up.

Results: There were 2 re-revisions for aseptic loosening. Radiographic ingrowth fixation was more frequent in minor intraoperative bone defects (p=0.011). Preoperative osteoporosis was related to the width of the medial and lateral cortex. Medial cortical thickness increased at different levels with a mean increase of 13.4% (p< 0.001) and the lateral cortical thickness showed a mean decrease of 2.7% at the proximal level. The femoral medial cortex tended to show a higher slope trend in periprosthetic fractures (p=0.015). The outside femoral diameter increased more rapidaly with an extended trochanteric osteotomy (p=0.007). The slope trend of the lateral and medial cortex was significantly higher at proximal levels in hips with a 10-inch stem (p=0.015).

Conclusions: Although without clinical relevance at the end of follow-up, femoral medial cortical thickness increased while frequently lateral cortical thickness decreased over time after an extensively porous -coated stem in revision hip surgery.

Revision surgery of the hip was performed on 114 hips using an extensively porous-coated femoral component. Of these, 95 hips (94 patients) had a mean follow-up of 10.2 years (5 to 17). No cortical struts were used and the cortical index and the femoral cortical width were measured at different levels.

There were two revisions for aseptic loosening. Survivorship at 12 years for all causes of failure was 96.9% (95% confidence interval 93.5 to 100) in the best-case scenario. Fibrous or unstable fixation was associated with major bone defects. The cortical index (p = 0.045) and the lateral cortical thickness (p = 0.008) decreased at the proximal level over time while the medial cortex increased (p = 0.001) at the proximal and distal levels. An increase in the proximal medial cortex was found in patients with an extended transtrochanteric osteotomy (p = 0.026) and in those with components shorter than 25 cm (p = 0.008).

The use of the extensively porous-coated femoral component can provide a solution for difficult cases in revision surgery. Radiological bony ingrowth is common. Although without clinical relevance at the end of follow-up, the thickness of the medial femoral cortex often increased while that of the lateral cortex decreased. In cases in which a shorter component was used and in those undertaken using an extended trochanteric osteotomy, there was a greater increase in thickness of the femoral cortex over time.

Introduction and purpose: Highly cross-linked polyethylenes (HXLPE) sterilized in an air-free environment have been used to prevent osteolysis and loosening of implants. This prospective randomized study analyzes the results of a series in which one single type of prosthesis but made with one of two different kinds of polyethylene (PE) has been used.

Materials and methods: We assessed 45 Allofit cups with a Sulene-PE liner (sterilized in nitrogen) and 45 with Durasul-PE liner (highly cross-linked) associated with an Alloclassic stem (femoral head: 28 mm) with a minimum follow-up of 5 years (mean 66.3 months). Femoral head penetration was analyzed by means of a digital program at 6 weeks, and at 6 and 12 months and once a year, using the Dorr method given the non-spherical shape of the cups.

Results: All assessed hips had good outcomes determined clinically and by x-rays. There was no loosening of any component. There were no radiolucent lines or osteolysis. Femoral head penetration at 6 weeks was 47.4% less in the Durasul group (0.19+0.06 mm for the Sulene-PE and 0.09+0.03 for the Durasul-PE [p< 0.0001]). Mean annual penetration was 20% less in the Durasul group (0.04+0.02 and 0.008+0.008 [p< 0.0001] respectively. The differences increased by the third year. Mean penetration at 5 years was 39.1% less in the Durasul group (p< 0.0001).

Conclusions: There was significant femoral reduction in the Durasul-PE group. Long term results are necessary to confirm that these prostheses lead to a lower rate of osteolysis.

Introduction: Bone stock in revision total hip arthroplasty is one of the most important issues for the orthopaedic surgeon. Different options have been described to manage acetabular bone defects. We reviewed the clinical and radiological results of two different uncemented oblong cups

Material and methods: 18 LOR (Sulzer) and 21 BOFOR (EndoPlus) uncemented cups were evaluated. Morsellized cancellous bone graft was used in all cases but 3. Mean follow-up was 31.6 months. Mean patient age was 72.3 years (32 to 91). Bone defects were classified according to Paprosky’s criteria. Clinical and radiological results were recorded.

Results: There have been no infections and no re-revisions in this series, although one patient is awaiting evaluation for re-revision. Clinical results improved according to the Harris Hip Score from 44 to 75 points. 34 cups were considered stable and 5 showed migration. All unstable cups were implanted in patients with type IIIA or IIIB bone defects. We observed the appearance of non-progressive radiolucent lines of less than 2 mm in 7 hips, sclerosis lines in 1 and acetabular osteolysis in 2.

Conclusions: Uncemented oblong cups are a valid option in revision total hip arthroplasty. The results were worse in patients with major acetabular bone defects. A longer follow-up is needed to evaluate these cups and confirm our findings.

Introduction: Modular metaphyseal-diaphyseal femoral stems are infrequent in primary total hip arthroplasty. We analyse the results of a proximally hydroxyapatite coated anatomic two-piece modular femoral stem over a minimum five years follow-up.

Material and Methods. 94 ESOP (Fournitures Hospitalieres, France) stems are analysed. The mean follow–up was 70.45 + 8.6 months. Patients’ mean age was 65.8 + 9.6 years. Proximal osteopenia and radiographic stem fixation are assessed according to Engh et al.

Results: There were 2 aseptic femoral stem loosenings. There were no cases with thigh pain. Three stems presented subsidence. Mean femoral canal filling was 89% and was related to stem subsidence (p< 0.05). Stable bone fixation was obtained in 83 hips and was related to fluted femora (p< 0.0001). The cumulative probability of not having radiographic loosening was 97.8% (94.8% to 100%). The cumulative probability of not having proximal femoral osteolysis was 86.0% (78.9% to 93.1%), cortical widening 88.1% (81.5% to 94.7%), and proximal osteopenia 94.5% (89.8% to 99.2%).

Conclusions: A cementless two-piece modular hydroxyapatite coated femoral stem provides good clinical results with an absence of pain and excellent radiographic results when there is good adaptation between the metaphyseal part of the stem and the femoral anatomy. This design is an option in femora with good bone quality and especially in tunnel-shaped cases. Femoral osteopenia and cortical widening were infrequent in this series. The modular metaphyseal-diaphyseal junction is not an in vivo problem, contrary to previous reports. A longer follow-up is needed to assess the results of this design.

Introdution. Gamma sterilisation in air produces free radicals in the polyethylene (PE) with the result of degrading its mechanical properties, increasing wear and debris, and producing osteolysis and loosening. PE sterilized in the absence of air and high cross-linked polyethylene (HXLPE) have been used to avoid osteolysis and loosening. This prospective randomized study has assessed results in a series using two different poly-ethylenes associated with the same prosthetic design.

Methods: We assessed 45 Allofit cups with Sulene-PE liner (sterilized with nitrogen) and 45 Allofit cups with Durasul-PE liner (HXLPE), both associated with an Alloclassic stem (28-mm femoral head) (Zimmer). The minimum follow-up is 5 years and the mean follow-up 66.3 months. The linear femoral head penetration was estimated at 6 weeks, at 6 and 12 months and annually thereafter, using a software package employing the Dorr method, given the nonspherical cup shape.

Results All assessed hips had good clinical and radiographic results. There was no loosening of any prosthetic component. There were no radiolucent lines or osteolysis. Femoral head penetration in the early postoperative radiographs was 47.4% less in the Durasul group (0.09+0.03 mm) than the Selene-PE group (0.19+0.06 mm)(p< 0.0001). The mean yearly linear femoral head penetration was 20% lower in the Durasul group (0.008+0.008) than the Sulene-PE group (0.04+0.02)(p< 0.0001). Differences increase after the third year. Mean linear femoral head penetration at 5 years was 39.1% less in the Durasul group (p< 0.0001).

Conclusions: Although the digitized method used is not totally accurate and is used only for a general estimate, there is a significant reduction in yearly linear femoral head penetration with Durasul-PE. Longer-term results are needed to confirm that this polyethylene generates less osteolysis.

Aim: To assess the clinical results, radiographic fixation and polyehtylene wear of a second generation cementless porous coated acetabular cup for a follow-up of 9.6 years

Material and Methods: 81 Duraloc 500 (De Puy) cups with polyethylene (PE) Enduron implanted between 1992–1995 are analysed. The mean follow-up was 9.6 years. Clinical results and radiographic fixation according to Jonhston et al. and according to Engh et al. were evaluated. PE mean wear and so-called “bedding in” process was estimated with anteroposterior pelvic radiographs which were digitized and analysed using a software package with Sychterz method. X-rays were measured at 6 weeks (zero position), 6 months, 12 months and annually thereafter. In all cases a Profile (De Puy) femoral stem was used

Results: There was 1 PE exchange because of a later dislocation (Kaplan-Meier survivorship 98.67 % at 10 years). All cups were osseointegrated. There was no osteolysis (Kaplan-Meier 100% at 10 years). There were no PE liner ruptures. Zero position (PE wear at 6 weeks) for PE was 0.1651 + 1339 mm and mean wear was 0.1108 + 0.793 mm.

Conclusions: All cups, except one, improved clinical results and showed stable fixation. There was no acetab-ular osteolysis in this series. In spite of a low zero position, mean PE wear was similar to other cups.

Introduction and purpose: This study analyzes the clinical and radiographic results of two generations of the same uncemented acetabular component.

Materials and methods: The analysis comprised 83 Harris-Galante I (HGI) shells (with a 32 mm femoral head) and 93 Harris-Galante II shells (HGII) (with a 28 mm femoral head. Mean follow-up was 12.5 + 2.52 years for the HGI shells and 7.8 + years for the HGII ones. PE wear was assessed by means of image digitalization and computer software (AutoCAD).

Results: There were two cases of loosening amongst the HGI shells (Kaplan-Meier 96.9%) and one among the HGII ones (98.3%) (p = 0.7107). 4 PE replacements had to be performed due to wear in the HGI (90.7%). There were three dislocations of the PE insert in the HGI shells ( 79.7%) and one in the HGII ones (97.9%) (p = 0.883). Acetabular osteolysis was observed in 7 cases, out of which 5 were HGI and 2 HGII,. The osteolysis was related to a higher initial settling on the PE (position zero) ( p = 0.0062), a higher mean wear rate (p = 0.001), and a higher wear rate at the end of follow-up (p = 0.002). Position zero was 0.15 + 0.04 mm for HGI shells and 0.11 + 0.02 for HGII ones (p < 0.001). The mean wear rate was 0.13 + 0.23 mm/year and 0.11 + 0.09 respectively (p = 0.740). PE insert dislocation appeared after an average of 117 + 60.3 months, with a position zero of 0.15 mm for dislocated shells and y 0.13 mm for non-dislocated ones. The respective mean wear rates were 0.94 mm and 0.10 mm (p = 0.001).

Conclusions: Stable radiographical fixation was observed in the majority of shells of both generations. Osteolysis was related with higher wear. The second generation shows a lower position zero which leads to less wear at the end of follow-up, but not to a lower mean wear rate.

Aim: Mean radiographic polyethylene wear can not distinghish between so-called Òbedding-inÒ and true wear in porous-coated cups (Sychterz 1999). Wear performance of two different generations of the same cement-less porous-coated cup are compared. Material and Methods: 83 Harris-Galante I (HGI) (32mm femoral head) and 93 Harris-Galante II (HGII) (28mm) cups are analyzed. The average follow-up was 11.5 yrs for HGPI and 6.7 years for HGPII cups. Anteroposterior pelvic radiographs (at 3 and 6 months and annually thereafter) were scanned digitally and linear wear was estimated using a software package with the Sychterz method. All radiographs were made following the same protocol. Results. Postoperative bedding-in was: 0.15±0.04 mm for HGI and 0.11±0.02 for HGII cups (p< 0.001). Femoral head penetration at the end of follow-up was: 1.50±0.28 mm for HGI and 0.85±0.01 for HGII. Mean wear excluding bedding-in was: 0.13±0.23 mm/year for HGI and 0.11±0.09 for HGII (p=0.740). The femoral head penetration rate was highest in the þrst two years and then decreased with the time and was similar in both groups. Conclusions: The digitized Sychterzñ method allows us to determine bedding-in and true polyethylene wear. The second generation cups show a decrease in the bedding-in process, but do not have a lower wear rate.