Cemented polyethylene cups in patients younger than 40 years

Risk Factors for Dislocation and Re-revision After First-Time Revision Total Hip Arthroplasty due to Recurrent Dislocation - A Study From the Danish Hip Arthroplasty Register

BACKGROUND

Persistent instability after hip revision is a serious problem. Our aim was to analyze surgical and patient-related risk factors for both a new dislocation and re-revision after first-time hip revision due to dislocation.

METHODS

We included patients with a primary THA due to osteoarthritis and a first-time revision due to dislocation registered in the Danish Hip Arthroplasty Register (DHR) from 1996 to 2016. We identified dislocations in the Danish National Patient Register and re-revisions in the DHR. Risk factors were analyzed by a multivariable regression analysis adjusting for the competing risk of death. Results are presented as subdistribution hazard ratios (sHR).

RESULTS

We identified 1678 first-time revisions due to dislocation. Of these, 22.4% had a new dislocation. 19.8% were re-revised for any reason. With new dislocations treated by closed reduction as the endpoint, the sHR was 0.36 (95% CI, 0.27-0.48) for those who had a constrained liner (CL) during revision and 0.21 (0.08-0.58) for dual mobility cups (DMC), thereby lowering the risk of dislocation compared to regular liners. Changing only the head/liner increased the risk of dislocation (sHR = 2.65; 2.05-3.42) compared to full cup revisions. The protective effect of CLs and DMCs on dislocations vanished when re-revisions became the endpoint. The head/liner exchange was still found inferior compared to cup revision (sHR = 1.73; 1.34-2.23).

CONCLUSION

Patients revised with DMCs and CLs were associated with a lower risk of dislocation after a first-time revision but not re-revision, whereas only changing the head/liner was associated with a higher risk of dislocation and re-revision of any cause compared to cup revision.

"True" Cumulative Incidence of and Risk Factors for Hip Dislocation within 2 Years After Primary Total Hip Arthroplasty Due to Osteoarthritis: A Nationwide Population-Based Study from the Danish Hip Arthroplasty Register

BACKGROUND

Hip dislocation is one of the leading indications for revision of total hip arthroplasty (THA) implants, and the extent of this complication is often measured by the number of revisions. The exact incidence of dislocation can be difficult to establish as closed reductions may not be captured in available registers. The purpose of this study was to identify the "true" cumulative incidence of hip dislocation (revisions and closed reductions) after primary THA, and the secondary aim was to identify risk factors for dislocation.

METHODS

From the Danish Hip Arthroplasty Register, we identified 31,105 primary THAs indicated by primary osteoarthritis that had been performed from 2010 to 2014 and had 2 years of follow-up. Dislocations were identified through extraction from the Danish National Patient Register. Matching diagnosis and procedure codes were deemed correct while non-matching codes were reviewed through a comprehensive, nationwide review of patient files. Risk factors were analyzed with multiple logistic regression analysis and presented as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Our review of patient files identified 1,861 dislocations in 1,079 THAs, which corresponds to a 2-year cumulative incidence of 3.5% (CI = 3.3% to 3.7%). This was a 50% increase compared with the correctly coded dislocations captured by administrative register data only. Patients who were <65 years of age had a lower dislocation risk (OR = 0.70; CI = 0.59 to 0.83) and those who were >75 years of age had a higher risk (OR = 1.32; CI = 1.14 to 1.52) compared with those who were 65 to 75. Male sex (OR = 0.86; CI = 0.75 to 0.98), cemented fixation (OR = 0.71; CI = 0.58 to 0.87), and lateral approach (OR = 0.28; CI = 0.16 to 0.49) were all associated with a lower risk. A head size of 32 mm was associated with a higher risk of dislocation (OR = 1.27; CI = 1.10 to 1.46) than 36-mm heads, whereas dual-mobility cups had a reduced risk (OR = 0.13; CI = 0.05 to 0.36).

CONCLUSIONS

We found the "true" cumulative incidence of dislocations within 2 years after primary THAs performed between 2010 and 2014 in Denmark to be 3.5%. Age, sex, American Society of Anesthesiologists (ASA) score, head size and type, fixation method, and surgical approach were independent significant factors for dislocation. Comprehensive search algorithms are needed in order to identify all dislocations so that this complication can be accurately reported in national registers.

A cemented cup with acetabular impaction bone grafting is more cost-effective than an uncemented cup in patients under 50 years

PURPOSE

Acetabular deficiencies in young patients can be restored in several ways during total hip arthroplasty. Currently, cementless cups are most frequently used. Impaction bone grafting of acetabular defects is a more biological approach, but is it cost-effective in young patients on the long term?

METHODS

We designed a decision model for a cost-utility analysis of a cemented cup with acetabular impaction bone grafting versus an uncemented cup, in terms of cost per quality-adjusted life year (QALY) for the young adult with acetabular bone deficiency, in need for a primary total hip arthroplasty. Outcome probabilities and effectiveness were derived from the Radboud University Nijmegen Medical Centre and the Norwegian Hip Register. Multiple sensitivity analyses were used to assess the contribution of the included variables in the model's outcome.

RESULTS

Cemented cups with impaction bone grafting were more cost-effective compared to the uncemented option in terms of costs per QALY. A scenario suggesting equal primary survival rates of both cemented and uncemented cups still showed an effect gain of the cemented cup with impaction bone grafting, but at higher costs.

CONCLUSIONS

Based on this model, the first choice of treatment of the acetabular bone deficient osteoarthritic hip in a young patient is reconstruction with impaction bone grafting and a cemented cup.

Favorable Results of Primary Total Hip Arthroplasty With Acetabular Impaction Bone Grafting for Large Segmental Bone Defects in Dysplastic Hips

BACKGROUND

The aim of the present study was to assess midterm results after acetabular impaction bone grafting (IBG) in primary total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) with large acetabular segmental defect.

METHODS

Primary THA with IBG for DDH with large acetabular segmental defect was performed in 40 hips of 38 patients. The average age was 61.6 years (range: 33-82 years), and the average follow-up period was 7.5 years (range: 3-10.3 years). The Merle d'Aubigné and Postel hip score and complications were assessed. For radiological assessment, postoperative location of the hip rotation center, the socket inclination angle, and the socket center-edge angle were assessed. Kaplan-Meier survival analysis was performed with the end points of any type of reoperation and aseptic acetabular loosening.

RESULTS

The mean Merle d'Aubigné and Postel hip score improved from 10.4 points to 16.2 points at the final follow-up. Reoperation was performed in 1 case for acute infection without loosening. In 39 out of 40 hips (97.5%), the center of hip rotation was located beneath the "high hip center." The average socket inclination angle was 39.3° (range: 30°-54°), and the average socket center-edge angle was -11.8° (range: -23° to 9°). Survival rate of acetabular component at 8 years with the end point of any reoperation and of aseptic loosening was 96.6% (95% confidence interval: 89.9%-100%) and 100%, respectively.

CONCLUSION

Acetabular IBG represents one of the useful options for restoring a normal hip center and acetabular bone stock in primary THA for DDH with large acetabular defect.

The biological approach in acetabular revision surgery: impaction bone grafting and a cemented cup

Acetabular impaction bone grafting (IBG) in combination with a cemented cup in revision total hip arthroplasty (THA) is a proven and well-recognised technique which has been used in clinical practice for more than 35 years. Nowadays, with cemented prostheses tending to lose a larger part of the THA market every year in primary and revision cases, and many young surgeons being only trained in implanting uncemented prostheses, this technique is considered by many as technically demanding and time consuming, making its use less appealing. Despite this image and many new innovative techniques using uncemented implants in acetabular revisions over the last 25 years, IBG with a cemented cup is still one of the few techniques that really can reconstitute bone and respects human biology. In this era of many biologically-based breakthroughs in medicine, it is hard to explain that the solution of most orthopaedic surgeons for the extensive bone defects as frequently seen during acetabular revision surgery, consists of implanting bigger and larger metal implants. This review aims to put the IBG method into a historical perspective, to describe the surgical technique and present the clinical results.

The results of acetabular impaction grafting in 129 primary cemented total hip arthroplasties

Between 1995 and 2003, 129 cemented primary THAs were performed using full acetabular impaction grafting to reconstruct acetabular deficiencies. These were classified as cavitary in 74 and segmental in 55 hips. Eighty-one patients were reviewed at mean 9.1 (6.2-14.3) years post-operatively. There were seven acetabular component revisions due to aseptic loosening, and a further 11 cases that had migrated >5mm or tilted >5° on radiological review - ten of which reported no symptoms. Kaplan-Meier analysis of revisions for aseptic loosening demonstrates 100% survival at nine years for cavitary defects compared to 82.6% for segmental defects. Our results suggest that the medium-term survival of this technique is excellent when used for purely cavitary defects but less predictable when used with large rim meshes in segmental defects.

Better primary stability with porous titanium particles than with bone particles in cemented impaction grafting: an in vitro study in synthetic acetabula

AIMS

Impaction bone grafting creates new bone stock after hip joint replacement. Utilizing a synthetic bone substitute instead of bone might increase primary stability and is not associated with graft shortage and pathogen transmission. This study compares the initial stability of a graft layer of porous titanium particles (TiP), cancellous bone particles, and a 1:2 bone-titanium mix in synthetic cemented acetabular reconstructions. Displacement was measured by radiostereometric analysis after cyclic loading (1 Hz, maximum stress 2.5 MPa). Shear stress resistance was quantified by a lever out test of the cup. Cement penetration was quantified from cross-sections.

FINDINGS

Titanium reconstructions showed less residual displacement (0.13 ± 0.13 mm) than pure bone particle reconstructions (0.57 ± 0.18 mm) (p < 0.01). Titanium reconstructions were also more resistant to shear stress (p < 0.001). The bone-titanium mix showed intermediate results. Cement penetrated deeper into the bone particle graft layers (4.8 ± 0.7) than into the titanium graft layers (3.8 ± 0.5 mm) (p < 0.02).

CONCLUSIONS

Cemented acetabular revision reconstructions with porous TiP show better initial stability despite less cement penetration than bone particle reconstructions. Realistic preclinical in vivo testing should explore the hypothesis that porous TiP offer a safe alternative to the current gold standard of bone grafts.

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

BACKGROUND

The number of total hip arthroplasties in patients under 30 years is increasing over the years. Almost all of them will face at least one or more future revisions in their life. Therefore, the implant used should have a high survival rate, and needs to be easily revisable resulting in a low re-revision rate. Several studies have evaluated the outcome of total hip arthroplasties in patients under 30 years. However, only a few reported on the follow-up outcome of 10 years or more. In addition, none of these reports published data of the subsequent revisions of these implants within their original report.

METHODS

We studied historically prospective collected data of 48 consecutive patients (69 hips) younger than 30 years, treated with a cemented primary total hip prosthesis between 1988 and 2004. Since the last evaluation of this cohort, two patients were lost to follow-up. For all hip revisions in this cohort, again cemented implants were used, mostly in combination with bone impaction grafting. Kaplan-Meier survival curves at 10- and 15 years for the primary total hip arthroplasties and revisions were determined.

RESULTS

The mean age at time of primary surgery was 25 years (range, 16 to 29 years). Mean follow-up of the primary hips was 11.5 years (range, 7 to 23 years). During follow-up 13 revisions were performed; in 3 cases a two-stage total revision was performed for septic loosening and 9 cups were revised for aseptic loosening. There were no aseptic stem revisions. The 10 and 15-year survival rates with endpoint revision for aseptic loosening of the primary total hip were 90% (95% CI: 79 to 96) and 82% (95% CI: 65 to 92) respectively. None of our 13 subsequent revisions needed a re-revision within 10 years after re-implantation.

CONCLUSIONS

Cemented total hip implants in patients under 30 years have an encouraging outcome at 10 and 15 years after surgery in these young patients. The 13 revised hips, treated with bone grafting and the third generation cement technique, were performing well with no re-revisions within ten years after surgery.

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.

High survivorship of cemented sockets with roof graft for severe acetabular dysplasia

BACKGROUND

Socket fixation in patients with acetabular dysplasia can be technically demanding but the use of structural grafts can help to reconstruct the original center of hip rotation. Because reported survival rates differ, construct survival seems to depend on the technique of graft preparation and fixation.

QUESTIONS/PURPOSES

What is the survivorship of cemented sockets with acetabular roof graft in patients with severe acetabular dysplasia? Do clinical scores equal those of patients without acetabular grafting?

METHODS

We retrospectively reviewed 62 patients (74 hips) who had undergone cemented THA with acetabular roof graft. Mean age at surgery was 45 years (range, 19-71 years). Revisions and radiographic failures were determined and clinical scores (Oxford, SF-12) were obtained and matched to a control group. Kaplan-Meier analysis was used to determine survivorship at a minimum followup of 5 years (mean, 10.4 years; range, 5-16 years).

RESULTS

Survivorship for all-cause revision was 98% (95% CI, 92.5%-100.0%) at 10 years followup. Two hips were revised for aseptic acetabular loosening and one hip for polyethylene wear. All grafts incorporated and no additional radiographic loosenings were seen. Patients with grafting had higher Oxford scores compared with the control group but other scores were equal.

CONCLUSIONS

In contrast to reported series and the common use of cementless cups in patients with developmental dysplasia of the hip, we found high survivorship of cemented sockets with roof graft in severe acetabular dysplasia at a mean followup of more than 10 years. These patients showed higher Oxford scores than patients in a control group. This technique that restores bone stock is a reasonable solution for often young patients with dysplasia.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Mid-term results of total hip arthroplasty with the CementLess Spotorno (CLS) system

BACKGROUND

Except for those reported by the designers, there are no published mid-term results of the use of the CementLess Spotorno (CLS) Total Hip Arthroplasty system. We present the results of (1) a ten to seventeen-year follow-up prospective cohort study of this system, and (2) retrospective analyses of factors influencing clinical and radiographic outcomes.

METHODS

We studied a series of 102 consecutive CLS arthroplasties with a minimal duration of follow-up of ten years. Indications for the procedures were osteoarthritis (n = 90), rheumatoid arthritis (n = 8), and femoral head osteonecrosis (n = 4). The Merle d'Aubigné-Postel score, polyethylene wear, and radiographic status were recorded at regular intervals. Survival analyses, repeated-measures analysis of variance, and a nested case-control study (with the cases having early revision due to aseptic cup loosening within ten years after the index procedure and the controls having no early cup revision) were used for evaluation.

RESULTS

There were fourteen revisions, including nine due to aseptic cup loosening. The ten-year Kaplan-Meier survival rate was 92.2% (95% confidence interval [CI] = 86.9 to 97.5) with revision for any reason as the end point. The fifteen-year survival rate was 78.4% (95% CI = 63.9 to 92.9) with revision for any reason as the end point, 81.6% (95% CI = 66.7 to 96.5) with revision due to aseptic cup loosening as the end point, and 99.0% (95% CI = 97.0 to 100.0) with revision due to aseptic stem loosening as the end point. The average amount of polyethylene wear at the time of final follow-up was 1.92 mm (range, 0.6 to 4.3 mm). The wear rate in the cases was significantly higher than that in the controls (0.31 vs. 0.16 mm/yr, p < 0.001). Factors with a significant effect on polyethylene wear were age at surgery (a 0.3-mm increase per every ten years younger, p = 0.001) and a larger head component (an effect of 0.53 mm for the 32 vs. the 28-mm component; p < 0.0001). Male sex had an effect of -0.66 point (p = 0.07) on the final Merle d'Aubigné-Postel score.

CONCLUSIONS

The results of this CLS system, particularly with regard to the femoral stem, are comparable with those with other reliable cementless systems. Nevertheless, the prevalence of aseptic acetabular cup loosening in the second decade after the operation demonstrates a potentially substantial problem with regard to long-term survival. A high polyethylene wear rate, male sex, a younger age at the time of surgery, and a 32-mm head component size are related to inferior clinical outcomes and a higher risk of implant revision.

The sit-to-stand movement: differences in performance between patients after primary total hip arthroplasty and revision total hip arthroplasty with acetabular bone impaction grafting

BACKGROUND

Little is known about the functional performance of patients after revision total hip arthroplasty with major acetabular bone impaction grafting. In general, these patients are assumed to perform worse due to a more advanced stage of periarticular tissue degeneration and multiple surgeries compared with patients with primary total hip arthroplasty (THA).

OBJECTIVE

The main purpose of this study was to quantify the differences in performance of the sit-to-stand (STS) movement between patients with primary THA and patients with revision THA.

DESIGN AND METHODS

In this study, the STS movement was analyzed kinematically (knee and hip angular extension velocity) and kinetically (loading symmetry ratio). Ten patients after primary THA and 10 patients after revision THA with acetabular bone impaction grafting were compared using these 3 rising parameters.

RESULTS

The patients with revision THA performed the STS movement comparably to the patients with primary THA; there were no differences in knee and hip velocity or leg asymmetry during rising.

LIMITATIONS

The study focused only on kinetic and kinematic aspects, and only patients who were satisfied with their THA were involved.

CONCLUSIONS

This study showed that patients after a revision THA with acetabular bone impaction grafting and cement did not perform the STS movement differently, either kinematically or kinetically, compared with patients with a primary THA.

Revisions of extensive acetabular defects with impaction grafting and a cement cup

BACKGROUND

Loosening of acetabular components often leads to bony defects. Management of extensive acetabular bone loss in hip revision arthroplasty can be a tremendous challenge.

QUESTIONS/PURPOSES

We asked whether a reconstruction with impacted bone grafts will provide a durable and pain-free function in extensive acetabular defects. We specifically determined the (1) survival rates with the end point of revision for any reason, aseptic revision, and radiographic loosening; (2) visual analog scale (VAS) pain score, Harris hip score (HHS), and the Oxford Hip Questionnaire score (OHQS); (3) number of repeat revisions; (4) complications; and (5) radiographic loosening, wear, and radiolucencies.

PATIENTS AND METHODS

We retrospectively followed 25 patients (27 hips) with extensive acetabular defects. No patient was lost to followup. Two patients died during followup. Minimum followup was 3 years (mean, 8.8 years; range, 3-14.1 years).

RESULTS

Three patients (three hips) underwent repeat revision surgery and another two patients (two hips) had radiographically loose hips. The 10-year survival rate was 88% (95% confidence interval, 74.2%-100%) with the end point acetabular revision for any reason and 95% (95% confidence interval, 86.0%-100%) with the end point acetabular revision for aseptic loosening. The mean HHSs were 55 points before surgery and 72 points postoperatively.

CONCLUSIONS

Acetabular reconstruction with impaction bone grafting and a cemented cup is a reliable technique with a 10-year survival rate of 88% in patients with extensive acetabular deficiencies.

LEVEL OF EVIDENCE

Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence.

Good results with cemented total hip arthroplasty in patients between 40 and 50 years of age

BACKGROUND AND PURPOSE

Total hip arthroplasties in young patients have lower long-term survival rates than in older patients. We evaluated the use of a unique treatment protocol in patients aged between 40 and 50 years. In all cases we used a cemented THA, and for acetabular deficiencies we also used impacted bone grafts together with a cemented cup.

METHODS

In 140 consecutive patients who were between 40 and 50 years of age at index surgery, 168 cemented total hip prostheses were evaluated after a mean follow-up time of 10 (2-19) years. Acetabular deficiencies were reconstructed with wire meshes and impacted bone grafts with a cemented cup (70 hips). During follow-up, 18 patients died (27 hips); in this group 3 hips (3 patients) had been revised. None of the patients were lost to follow-up. In all surviving patients, clinical assessment was performed with hip-score questions and all radiographs were evaluated.

RESULTS

All clinical questionnaires showed an improved clinical hip score. 29 hips (17%) were revised after a mean of 8 (0.3-18) years. Kaplan-Meier survival analysis showed a survival of 88% (95% CI: 82-94) after 10 years with revision of either component for any reason. Survival with endpoint revision for aseptic loosening of either component was 94% (95% CI: 90-99) after 10 years.

INTERPRETATION

Cemented implants in young patients have satisfying long-term results. Reconstruction of acetabular deficiencies with impacted bone grafts show promising results.

Total hip replacement in patients with multiple epiphyseal dysplasia with a mean follow-up of 15 years and survival analysis

The hip joint is commonly involved in multiple epiphyseal dysplasia and patients may require total hip replacement before the age of 30 years.

We retrospectively reviewed nine patients (16 hips) from four families. The diagnosis of multiple epiphyseal dysplasia was based on a family history, genetic counselling, clinical features and radiological findings. The mean age at surgery was 32 years (17 to 63), with a mean follow-up of 15.9 years (5.5 to 24).

Of the 16 hips, ten required revision at a mean of 12.5 years (5 to 15) consisting of complete revision of the acetabular component in three hips and isolated exchange of the liner in seven. No femoral component has loosened or required revision during the period of follow-up.

With revision for any reason, the 15-year survival was only 11.4% (95% confidence interval 1.4 to 21.4). However, when considering revision of the acetabular shell in isolation the survival at ten years was 93.7% (95% confidence interval 87.7 to 99.7), reducing to 76.7% (95% confidence interval 87.7 to 98.7) at 15 and 20 years, respectively.