Pooled outcome of total hip arthroplasty with the CementLess Spotorno (CLS) system: a comparative analysis of clinical studies and worldwide arthroplasty register data

Comparison of revision rates and epidemiological data of a single total knee arthroplasty system of different designs (cruciate retaining, posterior stabilized, mobile bearing, and fixed bearing): a meta-analysis and systematic review of clinical trials and national arthroplasty registries

BACKGROUND

This study aimed to meta-analyze epidemiological data, revision rates, and incidences of different designs of a single Total Knee Arthroplasty System and compare these factors across different countries.

METHODS

A systematic review was conducted on clinical studies and arthroplasty registries of ATTUNE TKA from 1999 to 2020. The main endpoints analyzed were revision rates and epidemiological data.

RESULTS

The average age of patients was 67.8 years, with a gender distribution of 60% female and 40% male. The pooled average BMI was 29.4 kg/m2. Eight clinical studies showed a pooled revision rate per 100 observed CY of 0.5 (n = 1343 cases). Cumulative revision rates after 1, 3, and 5 years varied among registries, with the Swiss registry having the highest revision data (after 5 years: 6.3%) and the American registry having the lowest revision data (after 5 years: 1.7%). A comparison of the revision rates of mobile bearing and fixed bearing (41,200 cases) as well as cruciate retaining and posterior stabilized (n = 123,361 cases) showed no significant advantage in the first 5 years after implantation.

CONCLUSION

In conclusion, pooled data from 41,200 cases of TKA with a single Total Knee Arthroplasty System in two arthroplasty registries revealed that there was no significant difference in revision rates between the mobile bearing and fixed bearing design within the first 5 years after implantation. In addition, a comparison of the revision rates in n = 123,361 cases showed no significant advantage for cruciate retaining or posterior stabilized in the first 5 years after implantation.

Clinical Performance of an Ultrashort, Proximally Porous-Coated and Tapered Metaphyseal-Fitting Cementless Femoral Stem Among Octogenarians

Total hip arthroplasty (THA) among octogenarians presents greater challenges than among the younger patient population because of the high risk of perioperative morbidity and mortality and poor bone quality. We determined the clinical performance and radiographic results of an ultrashort, proximally porous-coated and tapered metaphyseal-fitting cementless femoral stem for octogenarians. A total of 100 unselected octogenarians (112 hips) were included in this retrospective study. All patients received the ultrashort, proximally porous-coated and tapered cementless stem during the study period, but patients who could not walk preoperatively were excluded from the analysis. Their mean age was 82.3±12.1 years (range, 80-92 years). Assessment was performed with the Harris Hip Score; Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score; thigh pain; University of California, Los Angeles (UCLA) activity score; and radiographic results. The mean duration of follow-up was 7.6 years (range, 6-9 years). At the final follow-up, the mean Harris Hip Score was 87±13 points, the mean WOMAC score was 26±8 points, and the mean UCLA activity score was 4.5 points. Osseointegration was obtained for 105 (94%) acetabular components and 110 (98%) femoral components. Kaplan-Meier survivorship analysis at 9 years showed that the survival rate for the acetabular component was 94% (95% CI, 91-98) and that of the femoral component was 98% (95% CI, 91-100), with aseptic loosening or revision as the end point. The ultrashort cementless femoral component provides stable fixation without the need for diaphyseal fixation among octogenarians. [Orthopedics. 2022;45(3):181-186.].

Revision Rates After Total Ankle Replacement: A Comparison of Clinical Studies and Arthroplasty Registers

BACKGROUND

The aim of this study was to assess the outcome of total ankle replacement (TAR) regarding revision rates by comparing clinical studies of the last decade to data displayed in arthroplasty registers. The secondary aim was to evaluate whether dependent clinical studies show a superior outcome to independent publications. Additionally, revision rates of mobile bearing implants (MB-TARs) were compared to those of fixed bearing implants (FB-TARs).

METHODS

Clinical studies on TARs between 2010 and 2020 were systematically reviewed, with the endpoint being a revision for any reason. The parameter "revision rate per 100 observed component years (CYs)" was calculated for each publication. The pooled revision rate for clinical studies was compared to the data reported in arthroplasty registers. In a second step, revision rates were subdivided and analyzed for independent and dependent publications and for FB-TARs and MB-TARs.

RESULTS

A total of 43 publications met the inclusion criteria comprising 5806 TARs. A revision rate of 1.8 per 100 observed CYs was calculated, corresponding to a 7-year revision rate of 12.6%. The 3 arthroplasty registers included showed revision rates ranging from 8.2% to 12.3% after 7 years. No significant difference between dependent and independent publications nor between FB-TARs and MB-TARs was detected.

CONCLUSION

Revision rates of clinical studies and arthroplasty registers are comparable. Surgeons can compare their own revision rates with those from this study. Dependent studies do not seem to be biased, and no superiority for one bearing type can be described.

LEVEL OF EVIDENCE

Level III, systematic review of level III studies.

Survival Rate and Application Number of Total Hip Arthroplasty in Patients With Femoral Neck Fracture: An Analysis of Clinical Studies and National Arthroplasty Registers

BACKGROUND

Total hip arthroplasty (THA) is an increasingly popular treatment option for fractured neck of femur (NOF). The primary aim of this study is to systematically review all literature on primary THA and hemiarthroplasty (HA) after fractured NOF to calculate an overall revision rate. Furthermore, we wanted to compare primary THA implantations after fractured NOF between different countries in terms of THA number per inhabitant.

METHODS

All clinical studies on THA and HA for femoral neck fractures between 1999 and 2019 were reviewed and evaluated with a special interest on revision rate. Revision rate was calculated as "revision per 100 component years." THA registers were compared between different countries with respect to the number of primary implantations per inhabitant.

RESULTS

THA studies showed a mean revision rate of 11.8% after 10 years, which was lower than a 24.6% 10-year revision rate for HA. We identified 8 arthroplasty registers that revealed an annual average incidence of THA for fractured NOF of 9.7 per 100,000 inhabitants.

CONCLUSION

This study showed that patients with THA were less likely to be revised at 10 years compared to HA. We found similar annual numbers of THAs for fractured NOF per inhabitant across countries. The results of this analysis can be used to rank present and future national THA numbers within an international context.

Similar revision rates in clinical studies and arthroplasty registers and no bias for developer publications in unicompartmental knee arthroplasty

PURPOSE

Our aim was to assess the outcome with respect to cumulative revision rates of unicompartmental knee arthroplasty (UKA) by comparing published literature and arthroplasty registry data. Our hypothesis was that there is a superior outcome of UKA described in dependent clinical studies compared to independent studies or arthroplasty registers.

METHODS

A systematic review of all clinical studies on UKA in the past decade was conducted with the main endpoint revision rate. Revision rate was calculated as "revision per 100 component years (CY)". The respective data were analysed with regard to a potential difference of the percentage of performed revision surgeries as described in dependent and independent clinical studies. Clinical data were further compared to arthroplasty registers in a systematic search algorithm.

RESULTS

In total, 48 study cohorts fulfilled our inclusion criteria and revealed 1.11 revisions per 100 CY. This corresponds to a revision rate of 11.1% after 10 years. No deviations with regard to revision rates for UKA among dependent and independent clinical literature were detected. Data from four arthroplasty registers showed lower survival rates after 10 years compared to published literature without being significant.

CONCLUSIONS

The outcomes of UKA in dependent and independent clinical studies do not differ significantly and are in line with arthroplasty register datasets. We cannot confirm biased results and the authors recommend the use of UKAs in properly selected patients by experts in their field.

Long-Term Outcomes of Ultra-Short Metaphyseal-Fitting Anatomic Cementless Femoral Stem in Total Hip Arthroplasty With Ceramic-on-Ceramic Articulation for Young Patients

BACKGROUND

The aim of this study is to assess the long-term outcomes of this specific stem in patients younger than 50 years old, with regard to clinical and radiographic outcomes, survivorship, and complication rate.

METHODS

Two hundred thirty-nine consecutive series of patients (324 hips) who were younger than 50 years old at the time of surgery were enrolled in the study. Osteonecrosis (50%) and dysplastic hip (34%) were most common diagnoses. Patients were informed to use crutches or walker for 4 weeks to protect the femoral component against rotational stress. The mean follow-up was 15.6 years (range 14-17).

RESULTS

At the latest follow-up, the mean Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index score, and University of California, Los Angeles activity score were 93 points, 13 points, and 7 points, respectively. Three patients (1.3%) had moderate thigh pain. All of the acetabular components and 321 (99%) femoral stems were solidly fixed at the time of the latest follow-up. Three stems (0.9%) were revised for aseptic loosening. Two hips (0.6%) had a dislocation and 2 hips (0.6%) had a periprosthetic fracture. Ceramic fracture or osteolysis was not found in any hip at the time of the final follow-up. Survival rate of the femoral component was 99.1% (95% confidence interval 94-100) and that of the acetabular component was 100% (95% confidence interval 94-100) at 15.6 years.

CONCLUSION

In this series, THA using an ultra-short metaphyseal-fitting anatomic cementless femoral stem provided excellent long-term clinical and radiographic results in patients younger than 50 years old. Furthermore, our initial theoretical concerns about early aseptic loosening due to the absence of distal stem fixation were not justified.

Contemporary cemented versus uncemented hemiarthroplasty for the treatment of displaced intracapsular hip fractures: a meta-analysis of forty-two thousand forty-six hips

INTRODUCTION

Controversy exists regarding the use of cement for hemiarthroplasty to treat displaced intracapsular hip fractures. The aim of this systematic review and meta-analysis was to compare the clinical outcomes between contemporary cemented and contemporary uncemented hemiarthroplasty for the treatment of displaced femoral neck fractures.

METHODS

Literature searches of PubMed, Scopus, Web of Science, and Cochrane Central, up to May 2017, were performed. We included randomized controlled trials (RCTs) and observational studies comparing contemporary cemented with contemporary uncemented hemiarthroplasty. Data were pooled as mean difference (MD) or risk ratio (RR) with 95% confidence interval (CI) in a meta-analysis model. Studies with the Thompson and Austin Moore prostheses were excluded.

RESULTS

A total of 29 studies (9 RCTs and 20 observational studies), with a total of 42,046 hips, were included. Meta-analysis showed that the cemented group was associated with fewer periprosthetic fractures (RR = 0.44, 95% CI [0.21, 0.91]), longer operative time (MD = 11.25 min, 95% CI [9.85, 12.66]), more intraoperative blood loss (MD = 68.72 ml, 95% CI [50.76, 86.69]), and higher heterotopic ossification (RR = 1.79, 95% CI [1.11, 2.88]) compared with the uncemented group. Meta-analysis showed no significant difference in terms of post-operative hip function, hip pain, reoperation rate, prosthetic dislocations, aseptic loosening, wound infection, and hospital stay.

CONCLUSIONS

This meta-analysis shows that contemporary cemented prostheses have less intra-operative and post-operative fractures, but longer operative time, more intra-operative blood loss, and heterotopic ossifications. Otherwise, there were no significant differences between both groups.

No bias for developer publications and no difference between first-generation trochlear-resurfacing versus trochlear-cutting implants in 15,306 cases of patellofemoral joint arthroplasty

PURPOSE AND HYPOTHESIS

The study aim was to assess the outcome of patellofemoral arthroplasty (PFA), paying particular interest to 'revisions for any reason'. The hypothesis was that there is a superior outcome of PFA reported in dependent clinical studies in contrast to independent clinical literature and that there is a superior outcome of 'trochlear-cutting' PFA in comparison with 'first-generation trochlear-resurfacing' implants.

METHODS

Studies on PFA from its market introduction in 1955 onwards were systematically reviewed. The revision rate, which was calculated as 'revisions per 100 component years (CY)', was evaluated in 45 studies published in indexed, peer-reviewed international scientific journals. In addition, 'first-generation trochlear-resurfacing' and 'trochlear-cutting' implants as well as dependent and independent clinical literature were analysed. Furthermore, the data of three arthroplasty registers were analysed.

RESULTS

A total of 15,306 PFA were included consisting of 2266 cases in worldwide literature data and of 13,040 cases in register data. 2.22 revisions per 100 CY were observed in worldwide literature data, which corresponds to a revision rate of 22.2% after 10 years. Revision rates between 18.9 and 27% after 10 years were shown by the included three national joint registers. In the group analyses no significant differences were detected.

CONCLUSIONS

This meta-analysis did not reveal significant differences in the comparison between developer over independent publications and between 'first-generation-resurfacing' over 'trochlear-cutting' implants. In conclusion the data of developer publications do not seem to be biased. 'Trochlear-cutting' devices of PFA had slightly superior outcomes, but that benefit was not statistically significant. Nevertheless, we would recommend 'trochlear-cutting' devices for further use in PFA.

LEVEL OF EVIDENCE

Meta-analysis of Level IV case series.

Survival Rate of Short-Stem Hip Prostheses: A Comparative Analysis of Clinical Studies and National Arthroplasty Registers

BACKGROUND

The primary aim was to evaluate the outcome of short-stem hip prostheses in terms of overall revision rates. Data were taken from published literature and national arthroplasty registers. The second study aim was to evaluate a potentially superior outcome of dependent compared to independent clinical studies.

METHODS

All clinical studies on short-stem hip prostheses between 2006 and 2016 were reviewed and evaluated with a special interest on revision rates. Revision rate was calculated as "revision per 100 component years." Short stems were divided into femoral neck retaining (NR), neck sparing (NS), and neck harming (NH) prostheses. Published literature was further classified into dependent and independent studies, and data were compared to the Australian National Arthroplasty Register.

RESULTS

Fifty-two studies with 56 cohorts met the inclusion criteria and were therefore included in our study. All clinical studies showed a median revision rate of 4.8% after 10 years. NS and NH stems performed equally, whereas neck retaining prostheses were significantly inferior. Independent showed higher revision rates compared to dependent data without being statistically significant. The Australian register revealed a revision rate of 6.6% after one decade.

CONCLUSION

Similar low revision rates for NS and NH short-stem prostheses were found in the included data. Dependent studies seem not to be biased with regard to the longevity of short-stem hip replacement. Longer follow-up periods in clinical studies and more detailed information in arthroplasty registers would be desirable for future studies.

Revision total hip arthroplasty in the United States: national trends and in-hospital outcomes

PURPOSE

With the increasing number of primary total hip arthroplasties (THA) being performed, the frequency of revision surgery is also expected to increase. We analysed the immediate in-hospital complications and epidemiologic data of 3,469 revision and 18,186 primary THA cases.

METHODS

The National Hospital Discharge Survey (NHDS) was evaluated between 2001 and 2010 for patients who underwent revision and primary THA. Patients were identified and included in our retrospective study based on ICD-9 procedure codes.

RESULTS

The number of primary and revision THAs increased steadily from 2001 to 2010. The revision burden decreased for the same studied period (r = -0.92) to reach 13.9 % in 2010. The South region had higher revision burden of 17.4 % (p < 0.001). The primary THA group was more likely to be obese, morbidly obese, and have hypertension (p < 0.001). The revision THA group had an increased rate of blood transfusions (p < 0.001), deep venous thrombosis (p = 0.008), post-operative sepsis (p < 0.001), and wound complications (p < 0.001). The in-hospital mortality rate was also higher for the revision THA group (0.6 % versus 0.2 %, p < 0.001).

CONCLUSIONS

The revision burden has undergone a steady decrease over the ten years studied and the reason for this is likely multifactorial. The South region had a significantly higher revision burden when compared to the rest of the United States. Larger hospitals tend to perform relatively more revisions. Revision THA patients are associated with longer hospital stay, higher complications rate, and higher in-hospital mortality rate.

Outcomes of delayed total hip arthroplasty in patients with a previous ipsilateral acetabular fracture

Post-traumatic arthritis of the hip can develop in 12-57% of patients after an acetabular fracture. Once it develops, salvage treatment options include arthroplasty or arthrodesis. Delayed total hip arthroplasty (THA) has been shown to be a viable treatment option to decrease pain, improve stability and increase functional outcomes. Using cemented designs, earlier long-term studies reported satisfactory functional outcomes of delayed THA used to treat previously failed acetabular fractures. However, high aseptic loosening rates were also observed. Recent advances in cementless acetabular designs have shown comparable functional outcomes and loosening rates compared to those undergoing THA for non-traumatic arthritis. However, even with improvements in functional and radiographic outcomes, unique complications are commonly encountered in patients with previous acetabular fractures, including heterotopic bone around the hip, increased operative times and blood loss, aseptic loosening, sciatic nerve injury and dislocation. The outcomes and complications of delayed THA in patients with previous acetabular fracture will be reviewed.

High incidence of stem loosening in association with periprosthetic femur fractures in previously well-fixed cementless grit-blasted tapered-wedge stems

PURPOSE

Periprosthetic femur fracture is a potentially worrisome phenomenon for cementless stem fixation. The aim of this study was to document the incidence of stem loosening following periprosthetic femur fracture in previously well-fixed cementless grit-blasted tapered-wedge stems.

METHODS

We identified 36 periprosthetic femur fractures of either Vancouver B1 or B2 following hip arthroplasties using cementless grit-blasted tapered-wedge titanium stems at three participating institutions (GB group). The control group consisted of 21 periprosthetic femur fractures of either Vancouver B1 or B2 following hip arthroplasties using cementless proximal porous-coated stems at the same institutions during the same period of study (PC group). All femoral stems had been in a well-fixed state before occurrence of fracture. All patients were treated surgically and femoral stem stability was assessed using preoperative radiographs and confirmed by intraoperative scrutinization.

RESULTS

Seven (19.4%) of 36 fractures were Vancouver B1 and 29 (80.6%) were Vancouver B2 in the GB group, whereas 18 (85.7%) of 21 fractures were Vancouver B1 and 3 (14.3%) were Vancouver B2 in the PC group (P < 0.0001). The odds ratio for stem loosening was 24.86 (95% CI, 5.69-108.63) in the GB group versus the PC group.

CONCLUSIONS

Hip arthroplasty using cementless grit-blasted tapered-wedge titanium stems showed higher incidence of stem loosening in association with periprosthetic femur fracture than hip arthroplasty conducted using proximal porous-coated stems. A high index of suspicion of stem loosening might be necessary in periprosthetic femur fracture following hip arthroplasty using this type of stems.

Long-term results using the straight tapered femoral cementless hip stem in total hip arthroplasty: a minimum of twenty-year follow-up

We report the first long-term results of a prospective cohort study after total hip arthroplasty using the cementless Bicontact hip stem. Between 1987 and 1990, 250 total hip arthroplasties in 236 patients were performed using the cementless Bicontact hip stem. The average follow-up was 22.8 years (20.4-24.8) and average age at index surgery was 58.1 years. Eighty-one patients died and 9 were lost to follow-up. We noted 11 stem revisions revealing an overall Kaplan Meier survival rate of 95.0% (CI 95%: 91.1-97.2%). The average Harris Hip Score revealed 81 points (range 24-93). The Bicontact hip stem demonstrated high survival rates despite high ages and osteopenic changes, which are equivalent to other long-term reports of cementless stem fixation.

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.

[Aseptic, simultaneous and bilateral mobilisation due to an acetabular shell fracture in a 43 year-old patient]

The acetabular shell mobilization is the main long-term complication in total hip replacement. Metal-back fracture has also to be considered among the possible causes of shell mobilization. A case is presented of bilateral acetabular shell mobilization due to the trabecular covering de-soldering from the metal-back in a 43 year-old patient, 13-14 years after the first surgery.

Press-fit cementless acetabular fixation with and without screws

PURPOSE

Cementless acetabular fixation for total hip arthroplasty (THA) is widely used. The question of using screws for a better primary and secondary acetabular fixation has been discussed in the literature in recent years. The aim of this meta-analysis was to compare fixation of acetabular cups with and without screws in total hip arthroplasty.

METHODS

Electronic databases Embase, PubMed and Cochrane Library were used to search for randomised controlled trials reported through May 2013 of cementless acetabular fixation for THA with and without screws. Two independent reviewers assessed the trials for eligibility and quality. All related data matching our standards were abstracted for meta-analysis by RevMan 5.0. Evaluation criteria included revisions, migration and osteolysis.

RESULTS

A total of 1,130 THAs enrolled into five trials were included in this meta-analysis. All studies compared fixation of acetabular cups with and without screws, and our pooled data showed no statistical significance between the two surgical methods in revision, migration and osteolysis.

CONCLUSION

There is no significant difference between cementless acetabular fixation for THA with and without screws in revisions, migration or osteolysis.

Behaviour of the ultra-short anatomic cementless femoral stem in young and elderly patients

PURPOSE

The question arises as to whether it is possible to obtain rigid fixation of the ultra-short metaphyseal-fitting anatomic cementless stem without diaphyseal fixation in the elderly as well as younger patients. We investigated whether ultra-short, metaphyseal-fitting anatomic cementless femoral stem would provide similar functional improvements in the younger and elderly patients, radiographically secure implant fixation would be achieved in both groups, the bone content would be preserved in both groups, and complication rates would be similar in both groups.

METHODS

A total of 100 patients (114 hips) in the younger patient group and 100 patients (112 hips) in the elderly patient group were included in the study. Their mean age was 43.9 ± 6.11 years (range, 31-65 years) in the younger patient group and 78.9 ± 12.1 years (range, 66-91 years) in the elderly patient group. The mean duration of follow-up was 7.5 years (range, six to nine years) in the younger patient group and 7.6 years (range, six to nine years) in the elderly patient group.

RESULTS

The mean postoperative Harris hip scores (95 points versus 91 points), WOMAC scores (11 points versus 15 points), thigh pain (none in either group), UCLA activity scores (6.5 points versus 4.5 points), and radiographic results were not significantly different between the two groups. No hip in either group had an aseptic loosening. No hip in either group had clicking or squeaking sounds or ceramic fractures.

CONCLUSION

The cementless ultra-short, metaphyseal-fitting anatomic cementless femoral component provides stable fixation without any need of diaphyseal fixation in both younger and elderly patients. Despite the concern, the poor bone quality in elderly patients did not compromise the stability, and osseointegration of this ultra-short, anatomic cementless femoral stem was achieved in all elderly patients.