Long-term follow-up (11 years plus) results of JRI (Furlong) total hip arthroplasty in young patients: cause for concern regarding acetabular cup?

Hydroxyapatite ceramic-coated femoral components in younger patients followed up for 27 to 32 years

Aims

This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged less than 50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component.

Methods

We describe the survival, radiological, and functional outcomes of 33 patients (38 THAs) at a mean follow-up of 27 years (25 to 32) between 1988 and 2018.

Results

Of the surviving 30 patients (34 THAs), there were four periprosthetic fractures: one underwent femoral revision after 21 years, two had surgical fixation as the stem was deemed stable, and one was treated nonoperatively due to the patient's comorbidities. The periprosthetic fracture patients showed radiological evidence of change in bone stock around the femoral stem, which may have contributed to the fractures; this was reflected in change of the canal flare index at the proximal femur. Two patients (two hips) were lost to follow-up. Using aseptic loosening as the endpoint, 16 patients (18 hips; 48%) needed acetabular revision. None of the femoral components were revised for aseptic loosening, demonstrating 100% survival. The estimate of the cumulative proportion surviving for revisions due to any cause was 0.97 (standard error 0.03).

Conclusion

In young patients with high demands, the Furlong HAC-coated femoral component gives excellent long-term results.

Migration pattern of a short uncemented stem with or without collar: a randomised RSA-study with 2 years follow-up

BACKGROUND

There is an increasing interest in shorter, proximally loading, uncemented femoral stems. The aim of this study was to evaluate a new short stem type, its design based on a well-proven precursor, but with several new design features to facilitate easier insertion and possible preservation of proximal bone stock. It is available with or without a collar.

METHODS

The study includes 50 patients with primary osteoarthritis, mean age 59 (range 36-75) years, randomised to receive either the collar-fitted or the collarless stem. The patients underwent repeated radiostereometry (RSA) examinations (0, 0.5, 3, 12, 24 months), conventional radiography and filled out both hip-specific (HOOS) and general health (EQ-5D) questionnaires.

RESULTS

There was no statistically significant difference between the collared and collarless stems regarding migration and clinical outcome. Both stem types exhibit a similar pattern of initial subsidence (collared 0.63 mm vs. collarless 0.75 mm [p = 0.50]) and retroversion (collared 0.71° vs. collarless 0.97° [p = 0.36]) up to 3 months followed by stabilisation, in similarity with its precursors, suggesting good osseointegration. No stem has been revised or considered loose.

CONCLUSIONS

The new design features, including shortening the stem, do not compromise migration pattern or osseointegration, regardless collar or not.

3rd generation ceramic-on-ceramic cementless total hip arthroplasty: a minimum 10-year follow-up study

INTRODUCTION

3^rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings. The purpose of our study was to investigate the long-term clinical and radiographic results of 3^rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture.

METHODS

The database of the senior author (J.D.W.) was reviewed. A total of 126 hip replacements performed in 108 patients (average age 39.6 years) with an average follow-up of 12.1 years (10-16 years) was identified. Clinical notes and plain radiographs were reviewed. To measure function, patients were contacted and an Oxford Hip Questionnaire was completed. Patients were also directly questioned about the presence of squeaking or any other sounds from the hip. Radiographs were evaluated for signs of wear, osteolysis, loosening and heterotopic ossification. The abduction angle of the acetabular component was measured.

RESULTS

The average Oxford Hip Score was 39.8 out of 48. Survivorship at 10 years was 94.6% (95% CI) with revision for any cause as the endpoint. There was 1 femoral head fracture, no osteolysis, no squeaking and no detectable wear.

CONCLUSIONS

The good clinical and radiographic results for this series of patients are similar to other recent long-term studies looking at 3^rd generation ceramic-on-ceramic THA. The results compare favourably with other bearing surfaces. The lack of osteolysis associated with this articulation is encouraging and may also make it a good choice for younger patients requiring total hip replacement.

3rd generation ceramic-on-ceramic cementless total hip arthroplasty: a minimum 10-year follow-up study

INTRODUCTION

3rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings.The purpose of our study was to investigate the long-term clinical and radiographic results of 3rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture.

METHODS

The database of the senior author (J.D.W.) was reviewed. A total of 126 hip replacements performed in 108 patients (average age 39.6 years) with an average follow-up of 12.1 years (10-16 years) was identified. Clinical notes and plain radiographs were reviewed. To measure function, patients were contacted and an Oxford Hip Questionnaire was completed. Patients were also directly questioned about the presence of squeaking or any other sounds from the hip. Radiographs were evaluated for signs of wear, osteolysis, loosening and heterotopic ossification. The abduction angle of the acetabular component was measured.

RESULTS

The average Oxford Hip Score was 39.8 out of 48. Survivorship at 10 years was 94.6% (95% CI) with revision for any cause as the endpoint. There was 1 femoral head fracture, no osteolysis, no squeaking and no detectable wear.

CONCLUSIONS

The good clinical and radiographic results for this series of patients are similar to other recent long-term studies looking at 3rd generation ceramic-on-ceramic THA. The results compare favourably with other bearing surfaces. The lack of osteolysis associated with this articulation is encouraging and may also make it a good choice for younger patients requiring total hip replacement.

Survival of hydroxyapatite-coated cups: acetabular screws involve a lower rate of revision surgery due to aseptic loosening

BACKGROUND

It is believed that the path of acetabular screws may represent a shuttle between hydroxyapatite (HA) particles and the liner. The aim was to assess the relationship between acetabular screws and revision surgery for aseptic loosening in total hip arthroplasties (THAs).

MATERIAL AND METHODS

A retrospective multicentric study was performed. Patients older than 18 years and patients who underwent THA with both the stem and cup HA-coated were included. The rate of revision-surgery considering only aseptic loosening was calculated. The proportion of cases in which acetabular screws were used was registered, as well as the proportion of cups that showed osteolysis. The statistical relationship between acetabular screws and osteolysis, as well as acetabular screws and revision-surgery for aseptic loosening were assessed.

RESULTS

There were 749 cases. Mean age 62.1 (45-84) years. Mean follow-up 14.19 (8.9-16.7) years. Revision surgery was performed in 12.8% (96/749) of the cups. 73.95% (71/96) of the revised cups showed aseptic loosening. The overall 15-year survival of the cups considering only aseptic loosening was 84.4%. Acetabular screws were used in 47.5% (356/749) of the cups. Acetabular screws were used in 40.44% (55/136) of the cups that showed osteolysis. The use of acetabular screws was associated with less osteolysis (p = 0.006). Acetabular screws were used in 35.21% (25/71) of the cups that were revised for aseptic loosening. The use of acetabular screws was associated with a lower rate of revision surgery (p = 0.020).

CONCLUSIONS

In THA with the stem and cup HA-coated, the use of acetabular screws is associated with a lower rate of revision surgery.

Design modifications of the uncemented Furlong hip stem result in minor early subsidence but do not affect further stability: a randomized controlled RSA study with 5-year follow-up

BACKGROUND AND PURPOSE

Even small design modifications of uncemented hip stems may alter the postoperative 3-D migration pattern. The Furlong Active is an uncemented femoral stem which, in terms of design, is based on its precursor-the well-proven Furlong HAC-but has undergone several design changes. The collar has been removed on the Active stem along with the lateral fin; it is shorter and has more rounded edges in the proximal part. We compared the migration patterns of the uncemented Furlong HAC stem and the modified Furlong Active stem in a randomized, controlled trial over 5 years using radiostereometry (RSA).

PATIENTS AND METHODS

50 patients with primary osteoarthritis were randomized to receive either the HAC stem or the Active stem. The patients underwent repeated RSA examinations (postoperatively, at 3 months, and after 1, 2, and 5 years) and conventional radiography, and they also filled out hip-specific questionnaires.

RESULTS

During the first 3 months, the collarless Active stem subsided to a greater extent than the collar-fitted HAC stem (0.99 mm vs. 0.31 mm, p=0.05). There were, however, no other differences in movement measured by RSA or in clinical outcome between the 2 stems. After 3 months, both stem types had stabilized and almost no further migration was seen.

INTERPRETATION

The Active stem showed no signs of unfavorable migration. Our results suggest that the osseointegration is not compromised by the new design features.

The incidence of implant fractures after total hip arthroplasty

PURPOSE

Implant fractures after total hip arthroplasty (THA) are considered as rare in clinical practice. Nevertheless they are relevant complications for patients, physicians, and the public health system leading to high socioeconomic burdens. The aim of this study was to assess the incidence of fractures after THAs in a comparative analysis of clinical studies and worldwide arthroplasty register datasets.

METHODS

We calculated the pooled incidence of revision operations after fractures of THAs in a comparison of clinical studies published in Medline-listed journals and annual reports of worldwide arthroplasty registers in a structured literature analysis based on a standardised methodology.

RESULTS

Included clinical studies (sample-based datasets) were mono-centre trials comprising a cumulative number of approximately 70,000 primary implantations whereas worldwide national arthroplasty register datasets referred to 733,000 primary implantations, i.e. approximately ten times as many as sample-based datasets. In general, sample-based datasets presented higher revision rates than register datasets with a maximum deviation of a 14.5 ratio for ceramic heads, respectively. The incidence of implant fractures in total hip arthroplasty in pooled worldwide arthroplasty register datasets is 304 fractures per 100,000 implants. In other words, one out of 323 patients has to undergo revision surgery due to an implant fracture after THA in their lifetime.

CONCLUSIONS

Implant fractures in total hip arthroplasty occur in a relevant number of patients. The authors believe that comprehensive arthroplasty register datasets allow more general evaluations and conclusions on that topic in contrast to clinical studies.

Subcapital correction osteotomy for malunited slipped capital femoral epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE), causing posterior and inferior displacement and retroversion of the femoral head, is a well-recognized etiology for femoroacetabular impingement and can lead to premature arthritis in the young adult. The treatment of malunited SCFE remains controversial. Surgical dislocation and subcapital correction osteotomy (SCO) has been described as a powerful method to correct the proximal femoral deformity.

METHODS

Between January 2003 and January 2010, 11 patients (12 hips) with closed femoral physes and symptomatic femoroacetabular impingement from malunited SCFE were treated with surgical dislocation and SCO. We performed a retrospective review of patient histories, physical examinations, operative findings, and preoperative and postoperative anteroposterior (AP) and groin-lateral (GLat) radiographs. Mean follow-up was 61 months.

RESULTS

There were 4 female and 7 male patients with an average age of 15 years at the time of SCO. On the AP radiograph, the mean inferior femoral head displacement (AP epiphyseal-neck angle) was significantly improved (-26 to -6 degrees, P<0.001). On the GLat radiograph, the mean posterior femoral head displacement (lateral epiphyseal-neck angle) was significantly improved (-45 to -3 degrees, P<0.001). The mean α-angle was also significantly improved on both views (AP: 85 to 56 degrees, P<0.001; GLat: 85 to 46 degrees, P<0.001). Operative findings included 1 femoral osteochondral defect, 8 Outerbridge grade 3 to 4 acetabular cartilage lesions, and 10 labral lesions. Significant improvement of the mean Harris Hip Score was seen at latest follow-up (54 to 77, P=0.016). Complications occurred in 4 of the 12 cases with avascular necrosis in 2 patients, a worse postoperative Harris Hip Score in 1 patient, and failure of fixation treated successfully with revision open reduction internal fixation in 1 patient.

CONCLUSIONS

SCO as an adjunct to surgical dislocation and osteochondroplasty can be used to correct the deformity of the proximal femur associated with malunited SCFE. Normalization of proximal femoral anatomy may postpone progression to severe osteoarthritis and thus delay the need for arthroplasty in this young patient population. However, surgeons and patients should be aware that the risks of this procedure in this population are significant.

LEVEL OF EVIDENCE

Level IV-therapeutic study.

Hemiarthroplasties in young patients with osteonecrosis or a tumour of the proximal femur; an observational cohort study

Background

The failure scenario in total hip arthroplasty (THA), in younger patients, is dependent on the fixation and wear of the acetabular component. In selected cases, where endoprosthetic replacement of the femoral head is unavoidable for limb salvage or functional recovery, hemiarthroplasty can be chosen as an alternative. The purpose of this study is to evaluate hemiarthroplasty as treatment strategy for young patients with osteonecrosis or a tumour of the proximal femur.

Methods

Between 1985 and 2008, 42 hemiarthroplasties (unipolar and bipolar) were performed in patients younger than 65 years with osteonecrosis (n=13) or a tumour of the proximal femur (n=29). All patients were seen at yearly follow-up examination and evaluated. Revision or conversion to a THA was regarded as a failure of the implant. A Kaplan Meier analysis was performed. To determine significant differences between categorical groups, the Pearson chi-square test was used. In numerical groups the independent T-test and One-way ANOVA were used.

Results

After a mean follow-up of 7.1 years, failure of the hemiarthroplasty occurred 6 times. The Kaplan Meier survival analysis with conversion to THA or revision as endpoint of the bipolar hemiarthroplasties (n=38) shows a 96% survival at 15, and 60% at 20 years. In the unipolar type (n=4) we found a conversion rate of 50% within 3 years.

Conclusions

Bipolar hemiarthroplasty is a reasonable alternative in a young patient with osteonecrosis or a tumour of the proximal femur as indication. Because of the high conversion rate after unipolar hemiarthroplasties, we would not recommend this type of prosthesis in the young patient.

Hydroxyapatite-coated femoral stem/porous-coated acetabulum survivorship at 15 years

At 10 years, we reported survivorship of the Omnifit hydroxyapatite-coated femoral stem and the Omnifit-PSL porous-coated dual-radius acetabular shell (Stryker, Mahwah, NJ) with polyethylene liners sterilized by gamma radiation in air. Our 15-year follow-up examines survivorship and functional outcomes of this system. Ninety-two patients (98 hips) were identified from our database who had been involved with the prior study. The mean follow-up was 14.7 years (range, 11.8-17.0 years). Survival of the stem and cup was 98.8% and 69%, respectively. Osteolysis was seen in 56% of the proximal femur and 5% of the distal femur. This hydroxyapatite-coated stem continues to perform well at 15 years despite poor acetabular results. The performance of this acetabular component is consistent with previous literature.

Uncemented custom femoral components in hip arthroplasty. A prospective clinical study of 191 hips followed for at least 7 years

BACKGROUND AND PURPOSE

We have developed an individually designed, uncemented femoral component for achievement of improved strain distribution and fixation to the bone, to make uncemented stems more applicable in femurs of abnormal size and shape, and to improve the joint mechanics. Here we describe the design of the implant and present the results of a prospective clinical study with at least 7 years of follow-up.

PATIENTS AND METHODS

The prostheses are produced by CAD-CAM technique. The design of the stem is based on CT information, and the neck design is based on the surgeon's planning of the center of rotation, femoral head offset, and leg length correction. The first-generation stem produced before 2001 had a proximal HA coating and a sand-blasted distal part that was down-scaled to avoid contact with compact bone. The second-generation stem had a porous coating beneath the HA layer and the distal part of the stem was polished. The implant was used in 762 hips (614 patients) from 1995 until 2009. 191 of these hips were followed for 7 years and 83 others were followed for 10 years, and these hips are included in the present study. Mean age at surgery was 48 (20-65) years. Congenital dysplasia of the hip was the reason for osteoarthritis in 46% and 57% of the hips in respective groups. Merle d'Aubigné score was recorded in 152 and 75 hips in the two groups. Prostheses followed for 10 years, and almost all in the 7-year group, were first-generation stems.

RESULTS

The 7- and 10-year cumulative revision rates were 1.1% and 2.4%, respectively, with stem revision for any reason as endpoint. The clinical results were similar at 7 and 10 years, with Merle d'Aubigné scores of 17. Intraoperative trochanteric fissures occurred in 2 of the 191 operations (1.0%); both healed after wiring. In hips followed for 7 years, 2 periprosthetic fractures occurred; exchange of the stem was necessary in both. One additional fracture occurred between 7 and 10 years, and it was treated successfully with osteosynthesis. The rate of dislocation was 1.6% and 2.4%, respectively. There was no radiographic loosening at follow-up.

INTERPRETATION

Use of a custom femoral stem gives a reliable fixation and promising medium-term clinical results in femurs of normal and abnormal shape and dimension. The individual design, which enables optimized joint mechanics, gives a low risk of mechanical complications.

Early catastrophic acetabular failure in Furlong total hip replacements

The use of uncemented hip arthroplasty prostheses with ceramic articulations are popular, especially in the young, because of a perceived reduction in wear. We highlight a complication of ceramic on polyethylene articulating couples not previously described in the Furlong replacement. Despite widespread metalosis and particulate debris, osteolysis was not initially seen. The contamination compromised subsequent revision.

Cost-effectiveness analysis of periacetabular osteotomy

BACKGROUND

A lack of long-term outcomes data following periacetabular osteotomy makes it difficult for surgeons to recommend the most appropriate procedure to young patients who might be candidates for a joint-preserving procedure. In this study, we compared the cost-effectiveness of periacetabular osteotomy with total hip arthroplasty in terms of cost per quality-adjusted life year for the young adult.

METHODS

A decision model was constructed for a cost-utility analysis of periacetabular osteotomy compared with total hip arthroplasty. Outcome probabilities and effectiveness were derived from the literature. Effectiveness was expressed in quality-adjusted life years gained. Cost data were compiled and verified from our institution. Costs and utilities were discounted in accord with the United States Panel on Cost-Effectiveness in Health and Medicine. Principal outcome measures were average incremental costs, incremental effectiveness, incremental quality-adjusted life years, and net health benefits. Multivariate sensitivity analysis was used to assess the contribution of included variables in the model's outcomes.

RESULTS

For Tönnis grade-1 coxarthrosis, periacetabular osteotomy dominates with an average incremental cost-effectiveness of $7856 per quality-adjusted life year and an average incremental effectiveness of 0.15. For Tönnis grade-2 coxarthrosis, periacetabular osteotomy is, on the average, more cost-effective than total hip arthroplasty with an incremental cost-effectiveness of $824 per quality-adjusted life year, but it is less effective than total hip arthroplasty, on the average, with an incremental effectiveness of -1.4 quality-adjusted life years. Periacetabular osteotomy becomes more cost-effective at a longevity of 5.5 years for Tönnis grade-1 coxarthrosis and 18.25 years for Tönnis grade-2 coxarthrosis. In Tönnis grade-3 coxarthrosis, total hip replacement becomes the dominant treatment strategy.

CONCLUSIONS

Periacetabular osteotomy is, on the average, more cost-effective in Tönnis grade-1 and grade-2 coxarthrosis, while it is both more costly and less effective in Tönnis grade-3 coxarthrosis. These findings can inform clinical decision-making in the absence of long-term data. On the basis of this model, periacetabular osteotomy is preferable to total hip arthroplasty in Tönnis grade-1 and grade-2 coxarthrosis when the patient is sufficiently young and when functionality in sports is important.