Long-Term Survival of the Cemented Exeter Universal Stem in Patients 50 Years and Younger: An Update on 130 Hips

Treatment strategy and clinical outcomes of surgically managed hip periprosthetic fractures: analysis from a high-volume centre

BACKGROUND

Hip periprosthetic fractures (PPF) after total hip arthroplasty (THA) are becoming increasingly prevalent. Their management is secondary to the fracture type and the stability of the implant. This study aimed to provide the outcomes of operatively managed PPF from a high-volume centre to help guide future decision making.

METHODS

This was a retrospective study of prospectively collected data from January 2008 to January 2021. Patient demographics, implant specific details, and fixation strategy were collected. Complications including infection, reoperation, re-fracture, re-revision, were collected. Short-term mortality was evaluated at 3 months and 1 year. P-values <0.05 were considered significant.

RESULTS

282 surgically managed PPF were identified. Vancouver B2 were predominant in 52% of the cases. Revision alone and revision with additional fixation were the most frequent strategies in 168 cases (60%). Complications requiring reoperation occurred in 20% of the cases, with infection as the most frequent (8.5%). Mortality rate was 7.8% at 3 months and 15.7% at 1 year, with significantly lower rates in B2 type. B2 fractures treated with cemented stems had a significantly lower 1-year mortality than distal fit revisions.

CONCLUSIONS

PPF is associated with a high complication rate. Revision alone and revision with additional fixation remain the preferred method in B2/B3 type fractures, however, cemented revision can yield similar outcomes with lower short-term mortality. Considering the high-risk elderly and frail category of patients, a multidisciplinary team is necessary to improve outcomes and reduce mortality.

Birmingham Hip Resurfacing at 25 years

Aims

The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon's consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years.

Methods

The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken.

Results

Overall implant survival was 83.50% (95% confidence interval (CI) 0.79 to 0.90) at 25 years, and the number at risk was 79. Survival in male patients at 25 years was 89.5% (95% CI 0.83 to 0.96) compared to 66.9% for female patients (95% CI 0.51 to 0.83). Ten additional failures occurred in the period of ten to 25 years. These involved an adverse reaction to metal debris in four patients, a periprosthetic femoral neck fracture affecting five patients, and aseptic loosening in one patient. The median chromium levels were 49.50 nmol/l (interquartile range (IQR) 34 to 70), and the median cobalt serum levels were 42 nmol/l (IQR 24.50 to 71.25). The median OHS at last follow-up was 35 (IQR 10 to 48). During the 25-year study period, 29 patients died. Patient survival at 25 years was 75.10% (95% CI 0.67 to 0.83).

Conclusion

This study demonstrates that MoM hip resurfacing using the BHR provides a durable alternative to total hip arthroplasty (THA), particularly in younger male patients with osteoarthritis wishing to maintain a high level of function. These results compare favourably to the best results for THAs.

Quantification of trunnion damage in a series of intact total hip arthroplasty femoral stems previously identified to be at risk of catastrophic failure

BACKGROUND

Corrosion at the head-neck junction of femoral stems is a rare complication of total hip arthroplasty (THA) with manifestations ranging from subclinical wear to failure. Prior studies have identified a single femoral component design with an increased propensity for catastrophic trunnion failure. The purpose of the present study was to quantify trunnion damage of this femoral component retrieved from patients undergoing revision THA for non-trunnionosis indications.

METHODS

24 femoral components from a single manufacturer were identified for study inclusion. Each prosthesis underwent stereomicroscopic inspection. Corrosion and fretting scores were assigned per the Goldberg criteria to quadrants of the trunnion. Material loss was calculated based on cone angles across trunnion quadrants. This was carried out using a coordinate measuring machine that digitised each trunnion surface. Stems were compared to a series of femoral stems with the same trunnion design.

RESULTS

20 of the 24 (83%) trunnions demonstrated corrosion, all 24 trunnions demonstrated fretting. Corrosion scores did not statistically differ with respect to trunnion zone (p = 0.53), while fretting scores were higher in the inferior compared to the superior zones (p < 0.001). There was no significant difference in cone angles assessing material loss between stems (p = 0.25).

CONCLUSIONS

Evidence of trunnion damage was observed in each stem retrieved for non-trunnionosis revision. Fretting occurred more frequently about the inferior quadrants. However, digitised trunnion shapes were similar between compared stems exhibiting no material loss. Therefore, it is possible that previous reports of trunnion failures for this implant are not a systemic issue, and that further investigation is required.

The Clinical Frailty Scale is a Strong Predictor of 1-Year Mortality in Surgically Managed Hip Periprosthetic Fracture: An Analysis From a High-Volume Institution

BACKGROUND

Hip periprosthetic fractures (PPFs) after primary total hip arthroplasty are increasing with the number of primary implants and aging population. Mortality has been reported up to 34% at 1-year. The aim of this study was to evaluate the association of Clinical Frailty Scale (CFS) and 1-year mortality, complication rate, and length of stay (LOS) in surgically managed hip PPFs.

METHODS

This was a retrospective study of prospectively collected data from January 2008 to January 2021. A total of 282 surgically managed hip PPFs were identified. Mean age was 79 years (range, 42 to 106). Preoperative scores were analyzed through linear regression to identify significant association with mortality, complication and LOS. Receiver operating characteristic curve and Area Under the Curve (AUC) were generated to evaluate the quality of the models and the discriminatory ability of each clinical score. Significance was considered at P values < .05.

RESULTS

Mortality was 7.8% at 3-months and 15.7% at 1-year. Complication rate requiring surgery was 19.5% and mean LOS was 8.9 ± 7 days. The CFS was significantly associated with 3-month (odds ratio 2.23, P < .001) and 1-year mortality (odds ratio 2.01, P < .001). The receiver operating characteristic curve test for 1-year mortality showed a greater AUC for the CFS when compared with American Society for Anesthesiologists score and age-adjusted Charlson Comorbidity Index (AUC 0.80 versus 0.68 versus 0.72, respectively).

CONCLUSIONS

Frailty is a syndrome with increased risk of mortality after surgically managed PPF. The CFS can be easily assessed at the time of admission and could be considered as a strong and reliable predictor of 1-year mortality with a greater AUC than the conventionally used American Society for Anesthesiologists score.

Outcomes of Exeter cemented total hip arthroplasty in a county hospital: survivorship of eight hundred and ninety four hips with a minimum ten-year follow up

PURPOSE

A total of 894 hips were evaluated to describe the survivorship of Exeter cemented femoral stems and report the outcomes and complications of our 'Exeter- era', and there is no study from Central or Eastern Europe demonstrating similar results.

METHODS

Between January 2000 and December 2009, a total of 894 hips were included who underwent Exeter universal and V40 femoral stems with a mean follow up of 13 years. Cemented Exeter low profile polyethylene cups were used in 889 patients (99.4%) cups. Harris hip score (HHS) was used and statistical outcome measures were calculated with revision as an endpoint for aseptic loosening of the stem, aseptic loosening of any component, all-cause revision of the stem, and all-cause revision of the hip.

RESULTS

A total of 103 patients died and 129 (14.4%) operated hips were lost to follow-up before ten years. Out of the 662, ten stems (1.5%) were revised for aseptic loosening. Aseptic loosening of any component was the reason for revision in 43 cases (6.5%), consisting of 40 cup revisions and ten stem exchanges. Periprosthetic fracture occurred in 17 cases (1.9%) Periprosthetic joint infection occurred in 18 cases (2.01%). Three cups were exchanged for recurrent dislocation, and two stems had broken.

CONCLUSION

Exeter hip system has provided reproducible results across different centres worldwide, as it did in our series. Thorough surgical and cementing technique is of utmost importance for achieving these results. The cup is the weak point of the system and use of a hybrid system is worth considering.

What is the Role of Stem Size and Offset in the Risk of Nonseptic Revision of the Exeter® 150-mm Stem? A Study From the Swedish Arthroplasty Register

BACKGROUND

The Exeter® stem is used worldwide, often in older patients, and it is the second most commonly used cemented stem design in Sweden. Previous studies have shown that for cemented stems with a composite beam, the smallest sizes result in an increased risk of revision for mechanical failure. However, little is known about whether the survivorship of the polished Exeter stem, which generally has been shown to be good, might be associated with design parameters such as stem dimensions or offset at extreme implant sizes.

QUESTION/PURPOSE

Are differences in (1) stem size or (2) offset of the standard Exeter V40 150-mm stem associated with differences in the risk of stem revision for aseptic loosening?

METHODS

Between 2001 and 2020, 47,161 Exeter stems were reported to the Swedish Arthroplasty Register, with very high coverage and completeness documented during the period studied. In this cohort, we included patients with primary osteoarthritis who underwent surgery with a standard Exeter stem length of 150 mm and V40 cone with any type of cemented cups that had had at least 1000 reported insertions. This selection resulted in a study cohort representing 79% (37,619 of 47,161) of the total number of Exeter stems in the registry during that time. The primary study outcome was stem revision for aseptic indications such as loosening, periprosthetic fracture, dislocation, and implant fracture. A Cox regression was performed, with adjustment for age, gender, surgical approach, year of surgery, use of highly crosslinked polyethylene cups, and femoral head size and length dictated by the shape of the head trunnion. Adjusted hazard ratios are presented with 95% confidence intervals. Two separate analyses were performed. The first analysis excluded stems with the highest offsets (50 mm and 56 mm, which were not available for stem size 0). The second analysis excluded stem size 0 to include all offsets. Because stem survival was not proportional over time, we divided the analyses into two insertion periods, 0 to 8 years and beyond 8 years.

RESULTS

Stem size 0 (compared to size 1) was associated with an increased risk of revision up to 8 years when all stem sizes were included (first analysis 0 to 8 years, HR 1.7 [95% CI 1.2 to 2.3]; p = 0.002). Forty-four percent (63 of 144) of revisions of size 0 stems were for periprosthetic fracture. There was no consistent association between stem size and risk of aseptic stem revision when size 0 was excluded in the second analysis beyond 8 years. The most common offset (44 mm) was associated with an increased risk of revision (compared with 37.5 mm) up to 8 years when all sizes were included (first analysis, HR 1.6 [95% CI 1.1 to 2.1]; p = 0.01). In the second analysis (beyond 8 years, all offsets included), offset of 44 mm was compared with offset of 37.5 mm; compared with the first period, this offset was associated with a reduced risk (HR 0.6 [95% CI 0.4 to 0.9]; p = 0.005).

CONCLUSION

We found overall high survival of the Exeter stem, with generally little or no influence of stem variations on the risk of aseptic revision. However, stem size 0 was associated with an increased risk of revision mainly for periprosthetic fractures. If the femoral anatomy offers a choice between sizes 0 and 1 in patients with poor bone quality who are at risk of periprosthetic fracture, our data speak in favor of choosing the larger stem if the surgeon believes it is safe to insert the larger size, or, if available, another stem design that has a documented lower risk of this complication. For patients with good cortical bone quality but very narrow canals, a cementless stem may also be a good alternative.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Collarless Polished Tapered Stems of Identical Shape Provide Differing Outcomes for Stainless Steel and Cobalt Chrome: A Biomechanical Study

Cemented polished tapered femoral stems (PTS) made of cobalt-chrome alloy (CoCr) are a known risk factor for periprosthetic fracture (PPF). The mechanical differences between CoCr-PTS and stainless-steel (SUS) PTS were investigated. CoCr stems having the same shape and surface roughness as the SUS Exeter^® stem were manufactured and dynamic loading tests were performed on three each. Stem subsidence and the compressive force at the bone-cement interface were recorded. Tantalum balls were injected into the cement, and their movement was tracked to indicate cement movement. Stem motions in the cement were greater for the CoCr stems than for the SUS stems. In addition, although we found a significant positive correlation between stem subsidence and compressive force in all stems, CoCr stems generated a compressive force over three times higher than SUS stems at the bone-cement interface with the same stem subsidence (p < 0.01). The final stem subsidence amount and final force were greater in the CoCr group (p < 0.01), and the ratio of tantalum ball vertical distance to stem subsidence was significantly smaller for CoCr than for SUS (p < 0.01). CoCr stems appear to move more easily in cement than SUS stems, which might contribute to the increased occurrence of PPF with the use of CoCr-PTS.

Cemented versus Cementless Total Hip Arthroplasty for Femoral Head Osteonecrosis: A Study Based on National Claim Data in South Korea

INTRODUCTION

The purpose of this study was to compare the rates of revision, periprosthetic joint infection (PJI), and periprosthetic fracture (PPF) between patients with osteonecrosis of the femoral head (ONFH) undergoing noncemented total hip arthroplasty (THA) and cemented THA using a national claim data in South Korea.

METHODS

We identified patients who received THA for ONFH from January 2007 to December 2018 using ICD diagnosis codes and procedural codes. Patients were categorized into two groups according to the fixation method: with or without cement. The survivorship of THA was calculated using the following end points: revision of both the cup and stem, revision of the single component, any type of revision, PJI, and PPF.

RESULTS

A total of 40,606 patients: 3,738 patients (9.2%) with cement and 36,868 patients (90.7%) without cement, received THA for ONFH. The mean age of the noncemented fixation group (56.2 ± 13.2 years) was significantly lower than that of the cemented fixation group (57.0 ± 15.7 years, P = 0.003). The risk of revision and PJI was notably higher in cemented THA (hazard ratio: 1.44 [1.21 to 1.72] and 1.66 [1.36 to 2.04], respectively). Noncemented THA had a higher 12-year survivorship compared with cemented THA with any revision and PJI as the end point.

DISCUSSION

Noncemented fixation had better survivorship than cemented fixation in patients with ONFH.

The exeter cemented stem provides outstanding long-term fixation and bone load at 15 years follow-up: A systematic review and meta-analysis

PURPOSE

Since its introduction in 1988, the double-tapered polished Exeter cemented stem has been widely adopted in primary total hip arthroplasty (THA). Despite the results coming from the arthroplasty registries have proven great survivorship, the aim of this study was to dig deeper and describe the modes of failure of the Exeter stem at 15 years follow-up while reporting the clinical and radiographic outcomes.

METHODS

A search of PubMed, MEDLINE, and Embase was performed using the Preferred Reporting Items for Systematic Review and Meta-Analyses since inception of database to January 2022. A meta-analysis was performed on stem's failure rates and clinical outcomes using random effects models. Publication bias was assessed with funnel plots.

RESULTS

Overall, ten studies met the inclusion criteria with 2167 hips at mean 14.8 ± 4.1 years follow-up. The meta-effect estimate for revision rate for stem-related reasons was 3.8% (CI 95% 2.1-5.6, p < 0.01). The meta-effect for revision rate for stem aseptic loosening (AL) was 0.22% (CI 95% 0-0.4, p = 0.048) and for periprosthetic fracture was 0.6% (CI95% 0.3-0.9, p < 0.001). The meta effect estimate for Oxford Hip Score (OHS) at final follow-up was 32.4 (moderate; CI 95% 23.2-41.6, p <0.001) with and heterogeneity among the studies of I² 0%. Radiolucent lines were reported in 5.5% of cases, with 1.0% of cases (21 hips) reported to be progressive.

CONCLUSION

Current evidence suggests that the Exeter cemented stem not only has proven long-term outstanding reliability with a revision rate of 3.8%, but also incredibly low revision rates for AL (0.22%) and periprosthetic fracture (0.6%). It is suitable for a variety of indications, and the consistent radiological appearances indicate durable fixation and load transmission while being associated with a remarkably low stem-related complication rate.

Post-operative peri-prosthetic fracture rates following the use of cemented polished taper-slip stems for primary total hip arthroplasty: a systematic review

INTRODUCTION

Peri-prosthetic fractures (PPFs) are a serious complication of total hip arthroplasty (THA) associated with significant morbidity, mortality and re-operation similar to the rates seen following femoral neck fractures. When exploring the PPF rates around cemented stems, many studies combine the results of composite beam and taper-slip stems despite their different philosophies. This review looks specifically at PPFs with the use of cemented stems of the taper-slip philosophy to evaluate the demographics, PPF rate and fracture patterns in this patient cohort.

MATERIALS AND METHODS

A systematic search of Embase, Medline and CINAHL databases was performed to seek studies involving the use of cemented, polished, taper-slip stems, reporting on a rate of post-operative PPF and not involving patient cohorts that were exclusively hip fracture or revision arthroplasty.

RESULTS

27 studies reported on 505 PPFs with an average time from primary operation to PPF of 71.2 months (2-301 months). The average age of patients who sustained PPFs was 70.6 years (53.5-82 years) and the majority were female (64.2%). The Vancouver B2 fracture type was most common (39.5%). Open reduction and internal fixation represented the management of choice in 61.2% of PPFs. There was a re-operation rate of 11.4%.

CONCLUSION

This review suggests an association with being older and female, and a greater risk of PPFs secondary to low energy falls in cemented polished taper-slip stems.

Results of Hip Arthroplasty Using a COREN Stem at a Minimum of Ten Years

Purpose

We report on the 10-year clinical hip function and radiologic outcomes of patients who underwent hip arthroplasty using a COREN stem.

Materials and Methods

A consecutive series of 224 primary cementless hip arthroplasty implantations were performed using a COREN stem between 2009 and 2011; among these, evaluation of 128 hips was performed during a minimum follow-up period of 10 years. The mean age of patients was 65.4 years (range, 40-82 years) and the mean duration of follow-up was 10.8 years (range, 10-12 years). Evaluation of clinical hip function and radiologic implant outcomes was performed according to clinical score, thigh pain, and radiologic analysis.

Results

Dramatic improvement of the mean Harris hip score (HHS) from 59.4 preoperatively to 93.5 was observed at the final follow-up (P≤0.01). Stable fixation was demonstrated for all implants with no change in position except for one case of Vancouver type B2 periprosthetic femur fracture. A radiolucent line (RLL) was observed in 16 hips (12.5%). Thigh pain was observed in only two hips (1.6%) at the final follow-up. There were no cases of osteolysis around the stem. The survival rate for the COREN stem was 97.7%.

Conclusion

Good long-term survival with excellent clinical and radiological outcomes can be achieved using the COREN femoral stem regardless of Dorr type.

Favorable revision-free survivorship of cemented arthroplasty following failed proximal femoral nail antirotation: a case series with a median follow-up of 10 years

BACKGROUND

Given the ever-increasing rate of failure related to proximal femoral nail antirotation (PFNA), it is expected that an increasing number of PFNA individuals will undergo conversion to total hip arthroplasty (THA). The long-term survivorship of conversion of the initial PFNA to cemented THA is still debated. The aim of this retrospective study was to assess the long-term revision-free survivorship of cemented THAs after initial failures of PFNA in geriatric individuals.

METHODS

Consecutive geriatric individuals who underwent secondary cemented THA after initial PFNA fixation from July 2005 to July 2018, were retrospectively identified from three medical centres. The primary outcome was revision-free survivorship estimated using the Kaplan-Meier method and Cox proportional hazards regression with revision for any reason as the endpoint; secondary outcomes were functional outcomes and key THA-related complications. Follow-ups occurred at 3 months, 6 months, 12 months and then every 12 months after conversion.

RESULTS

In total, 186 consecutive patients (186 hips) were available for study inclusion. The median follow-up was 120.7 months (60-180 months) in the cohort. Kaplan-Meier survivorship with revision for any reason as the end point showed that the 10-year revision-free survival rate was 0.852 (95% confidence interval [CI], 0.771-0.890). Good functional outcomes were seen, and the HHS decreased markedly over the 24th month to the final follow-up interval from 92.2 to 75.1 (each p < 0.05). The overall rate of key THA-related complications was 16.1% (30/186).

CONCLUSION

Cemented THA executed following initial PFNA failure may yield satisfactory revision-free survival and, at least for the initial 10 years after conversion, good functional outcomes and a 16.1% complication rate of key THA-related complications, which supports the trend towards increased use of cemented THA.

Minimum 10-Year Follow-Up of Total Hip Arthroplasty With a Collarless Triple-Tapered Polished Cemented Stem With Line-to-Line Implantation Using a Direct Anterior Approach

BACKGROUND

The Trilliance stem (B. Braun-Aesculap, Tuttlingen, Germany), a novel collarless triple-tapered polished stem, was introduced in 2009. The aim of this study is to evaluate the long-term clinical and radiological results of the Trilliance stem with line-to-line implantation in primary total hip arthroplasty using a direct anterior approach.

METHODS

A consecutive retrospective series of 130 patients (151 hips) who underwent total hip arthroplasty between February 2009 and August 2011 were evaluated for a minimum of 10 years. Of these, 87.4% had a diagnosis of secondary osteoarthritis based on developmental hip dysplasia. Clinical and radiological results, complications were evaluated and survival analysis was performed.

RESULTS

The mean follow-up was 10.7 years (range, 10.0-12.1). Thirteen hips (13 patients, 6.8%) were lost to follow-up. Adequate cementation (Barrack grade A) was achieved in 136 hips (93.8%) 1 week post-operatively. Nearly all (144 hips, 99.3%) had been inserted within the range of 3°. No significant differences were identified between high- (≥30 procedures/year) and low- (<30 procedures/year) volume surgeons. The Kaplan-Meier survival analysis with revision of the femoral component for aseptic loosening, revision of the femoral component for any reason and revision of either component for any reason as the end points, cumulative survivorship was 100.0%, 97.6% (95% confidence interval (CI) 95.4-100.0) and 96.5% (95% CI 93.8-99.3) at 10 years, respectively.

CONCLUSION

The Trilliance stem with line-to-line implantation using a direct anterior approach has an excellent clinical and radiological outcome at a minimum of 10 years' follow-up.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

Long-term survival of hybrid total hip replacement for prior failed proximal femoral nail antirotation: a retrospective study with a median 10-year follow-up

Background

Hybrid total hip replacement (THR) is commonly used in the management of proximal femur fractures in elderly individuals. However, in the context of the revision, the literature on hybrid THR is limited, and differences in the long-term survival outcomes reported in the literature are obvious. This retrospective study aimed to evaluate the long-term survival of hybrid THR for failed proximal femoral nail antirotation (PFNA) in elderly individuals aged ≥ 75 years.

Methods

An observational cohort of 227 consecutive individuals aged ≥ 75 years who experienced hybrid THRs following prior primary PFNAs was retrospectively identified from the Joint Surgery Centre, the First Affiliated Hospital, Sun Yat-sen University. Implant survival was estimated using the Kaplan–Meier method. The primary end point was the implant survivorship calculated using the Kaplan–Meier method with revision for any reason as the end point; secondary end points were the function score measured using the modified Harris Hip Score (mHHS) and the incidence of main orthopaedic complications.

Results

In total, 118 individuals (118 THRs) were assessed as available. The median follow-up was 10 (3–11) years. The 10-year survivorship with revision for any reason as the endpoint was 0.914 (95% confidence interval [CI], 0.843–0.960). The most common indication for revision was aseptic loosening (70.0%), followed by periprosthetic fracture (30.0%). At the final follow-up, the median functional score was 83.6 (79.0–94.0). Among the 118 patients included in this study, 16 experienced 26 implant-related complications. The overall incidence of key orthopaedic complications was 13.5% (16/118).

Conclusion

For patients aged ≥ 75 years old with prior failed PFNAs, hybrid THR may yield satisfactory long-term survival, with good functional outcomes and a low rate of key orthopaedic complications.

Comparing uncemented, hybrid and cemented primary total hip arthroplasty in young patients, a New Zealand Joint Registry study

BACKGROUND

Despite increasing use of uncemented implants in young patients undergoing total hip arthroplasty (THA), there is minimal evidence for specific implant combinations in this group. We analysed the most commonly used uncemented (Corail-Pinnacle), hybrid (Exeter-Trident/Tritanium), and fully cemented (Exeter) implant combinations in the New Zealand Joint Registry (NZJR) in patients aged under 40 and between 40 and 55 years.

METHODS

All THAs recorded in the NZJR between 1999 and 2018 were included. The 40-55 and < 40 age groups were analysed separately. Demographic data, implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the NZJR, and detailed survival analyses were performed. The primary outcome was revision for any reason.

RESULTS

We identified 4152 THAs in the 40-55 group and 422 in the < 40 group. In the 40-55 group, revision rates and patient-reported outcome measure scores were comparable between the uncemented implant combination (0.70/100 component years) and the hybrid implant combination (0.62/100 component years), whereas the cemented implant combination exhibited a statistically significant higher revision rate (1.75/100 component years) (p < 0.001). In the < 40 group, revision rate for the hybrid implant combination (0.46/100 component years) was significantly lower than the uncemented implant combination (1.54/100 component years).

CONCLUSION

The most commonly used hybrid and uncemented implant combinations provided equivalent survival and functional outcomes in patients aged 40-55 years. More research is required to guide implant selection in patients aged < 40 years. The authors suggest a transition away from comparing classes of implants (cemented, uncemented, hybrid) given the diverse product range within these categories.

The influence of calcar collar and surface finish in the cemented femoral component on the incidence of postoperative periprosthetic femoral fracture at a minimum of five years after primary total hip arthroplasty

INTRODUCTION

Cemented femoral component design including its mechanical behavior in total hip arthroplasty (THA) has influenced the occurrence of postoperative periprosthetic femoral fracture (PPFF). The main aim of this study was to investigate the influence of the calcar collar and surface finish in the cemented femoral component on the risk of PPFF.

MATERIALS AND METHODS

This retrospective review was undertaken of 1082 primary THAs in 912 patients using cemented femoral components followed for a minimum of five years (mean, 9.4 years; range, 5-24 years). The incidence of PPFF, patients' demographics and surgical details were evaluated. Kaplan-Meier survivorship analysis was performed for four different outcomes: any PPFF, revision of the femoral component for PPFF, aseptic loosening, and for any reason.

RESULTS

The overall incidence of PPFFs was 1.0% (n = 11): 1.4% (n = 10) in the collarless polished (CLP) group, none in the collared polished (CP) group and 0.6% (n = 1) in the collared non-polished (CNP) group (p > 0.05). Kaplan-Meier survival analysis for the femoral component at 12 years with PPFF as the end point was 97.4% (95% confidence interval [CI], 94.9 to 99.8) in the collarless group and 99.7% (95% CI, 99.1 to 100) in the collared group (p = 0.048). With revision of the femoral component for aseptic loosening as the end point, survivorship was 100.0% in the CLP and CP groups, and 98.1% (95% CI, 95.9 to 100) in the CNP group (CLP vs CP, p > 0.999; CLP vs CNP, p = 0.001; CP vs CNP, p = 0.112).

CONCLUSION

This study demonstrated that the calcar collar in the cemented femoral component could play an important role to reduce the incidence of PPFF. The surface finish in the cemented femoral components influenced the incidence of femoral component revision for aseptic loosening over 5-12 years. Surgeons should consider not only the geometry and the mechanical function of the femoral components based on different design philosophies, but also potential complications associated with different designs that may require revision arthroplasty.

A 2-year prospective clinical and bone density evaluation, with a subset undergoing radiostereometric analysis, using the Absolut cemented stem

Background

Total hip arthroplasty (THA) is common though the investigation of new prostheses requires a practical, step‐wise introduction. This study reports the 2‐year clinical results and periprosthetic bone mineral density (BMD) changes, along with a subset undergoing Radiostereometric analysis (RSA), in patients undergoing primary cemented THA using a new highly polished, double tapered, collarless femoral stem (Absolut).

Methods

Between August 2013 and December 2016, 47 patients with a mean age of 74.2 years (range 36–89) underwent 51 THAs with the Absolut. All patients underwent clinical assessment pre‐surgery and at 6 weeks, 3, 12 and 24 months using the Oxford and Harris Hip Scores, as well as Dual Energy X‐ray Absorptiometry (DEXA) to assess BMD within 2–4 weeks post‐surgery, 12 and 24 months. RSA was undertaken in a patient subset (the first n = 30) early post‐surgery (1–2 days) and 3, 12 and 24 months.

Results

All clinical scores significantly improved (p < 0.05). RSA revealed a mean subsidence of 0.78 mm at 3 months, 1.23 mm at 12 months and 1.51 mm at 24 months. Anterior–posterior and medial‐lateral translation was negligible. A significant increase (p = 0.020) in BMD was observed in Gruen zone 1, though no significant changes were observed for any other zone up until 2 years. Two patients acquired an early post‐operative deep vein thrombosis that were treated accordingly and resolved, with no further complications or re‐operations.

Conclusion

The Absolut cemented femoral stem demonstrated good outcomes, BMD changes consistent with sound prosthesis integration and patterns of post‐operative micromotion observed in other successful cemented stems.

Should patient age thresholds dictate fixation strategy in total hip arthroplasty?

AIMS

Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost.

METHODS

In a high-volume, tertiary referral centre, we identified 10,112 THAs from a prospectively collected database, including 1,699 cemented THAs, 5,782 hybrid THAs, and 2,631 cementless THAs. The endpoint was revision for any reason. Secondary analysis included examination of implant survivorship in patients aged over 70 years, over 75 years, and over 80 years at primary THA.

RESULTS

Cemented fixation had the lowest implant survival in all age groups, with a total ten-year survivorship of 97.0% (95% confidence interval (CI) 95.8 to 97.8) in the cemented group, 97.6% (95% CI 96.9 to 98.1) in the hybrid group, and 97.9% (95% CI 96.9 to 98.6) in the cementless group. This was not statistically significant (p = 0.092). There was no age group where cemented fixation outperformed hybrid or cementless fixation.

CONCLUSION

While all fixation techniques performed well at long-term follow-up, cemented fixation was associated with the lowest implant survival in all age groups, including in more elderly patients. We recommend that surgeons should carefully monitor their own outcomes and use fixation techniques that they are familiar with, and deliver the best outcomes in their own hands. Cite this article: Bone Joint J 2022;104-B(2):206-211.

Cause-Specific Stem Revision Risk in Primary Total Hip Arthroplasty Using Cemented vs Cementless Femoral Stem Fixation in a US Cohort

BACKGROUND

We sought to evaluate the cause-specific revision risk following hybrid (cemented stem mated to a cementless acetabular implant) vs cementless total hip arthroplasty (THA) in a US cohort.

METHODS

Primary elective THA for osteoarthritis was identified using Kaiser Permanente's Total Joint Replacement Registry (2001-2018). Multivariable Cox regression was used to evaluate cause-specific revision, including aseptic loosening, infection, instability, and periprosthetic fracture (PPF), for hybrid vs cementless THA. Analysis was stratified by age (<65, 65-74, and ≥75 years) and gender.

RESULTS

The study cohort comprised 88,830 THAs, including 4539 (5.1%) hybrid THAs. In stratified analysis, hybrid THA had a higher revision risk for loosening in females in all 3 age subgroups. A lower risk of revision for PPF was observed following hybrid THA in females aged ≥75 years. For females ≥75 years, cementless THA had an excess PPF risk of 0.9% while hybrid THA had an excess loosening risk of 0.2%, translating to a theoretical prevention of 10 PPF revisions but a price of 3 loosening revisions per 1000 hybrid THAs. No difference in revision risk was observed in males.

CONCLUSION

We observed differences in cause-specific revision risks by method of stem fixation which depended upon patient age and gender. Although the trend toward all cementless fixation continue, there may be a role for hybrid fixation in females ≥75 years to mitigate risk for revision due to PPF at the potential cost of a slight increase in longer term aseptic loosening.

LEVEL OF EVIDENCE

Level III.

Midterm Results of Primary Exeter Cemented Stem in a Select Patient Population

BACKGROUND

Most North American surgeons predominantly use uncemented stems in primary total hip arthroplasties (THAs) and reserve cemented stems for selected older patients and those with poor bone quality. However, data on this "selective use" strategy for cemented stems in the population at risk for periprosthetic fracture and implant loosening are limited. The purpose of this study was to describe implant survivorship, complications, and radiographic results of a specific collarless, polished, tapered cemented stem (Exeter; Stryker) used selectively in a predominantly elderly population undergoing primary THA.

METHODS

We identified 386 patients who underwent a total of 423 primary THAs with selectively utilized Exeter stems for the treatment of osteoarthritis between 2006 and 2017. In the same time period, 11,010 primary THAs were performed with uncemented stems and 961 with non-Exeter cemented stems. The mean patient age was 77 years, 71% were female, and the mean body mass index was 29 kg/m2. Competing risk analysis accounting for death was utilized to determine cumulative incidences of revision and reoperation. The mean follow-up was 5 years (range, 2 to 12 years).

RESULTS

The 10-year cumulative incidence of any femoral component revision in this patient cohort was 4%, with 10 stems revised at the time of the latest follow-up. There were no intraoperative femoral fractures. The indications for revision were postoperative periprosthetic femoral fracture (n = 6), dislocation (n = 3), and infection (n = 1). There were no revisions for femoral loosening. The 10-year cumulative incidence of reoperation was 10%. The 10-year cumulative incidence of Vancouver B periprosthetic femoral fracture was 2%. Radiographically, there were no cases of aseptic loosening or osteolysis. There was a significant improvement in median Harris hip score, from 53 preoperatively to 92 at a mean follow-up of 5 years (p < 0.001).

CONCLUSIONS

The strategy of selectively utilizing a collarless, polished, tapered cemented stem produced a low (4%) cumulative incidence of stem revision at 10 years postoperatively and resulted in no cases of aseptic loosening. The use of the Exeter stem did not eliminate postoperative femoral fractures in this predominantly elderly, female patient population.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Effects of Rasp Oversize on the Clinical and Radiographic Outcomes of Total Hip Arthroplasty With a Collared Satin-Finished Composite Beam Cemented Stem

BACKGROUND

This study aimed to compare the clinical and radiographic outcomes of using two different oversized rasps in total hip arthroplasty (THA) with a composite beam cemented stem (DCM-J).

METHODS

A consecutive series of 105 hips underwent hybrid THA using the DCM-J stem between 2006 and 2010. Among the patients with a minimum 10-year follow-up, a 1.5-mm oversized rasp was used in 38 hips (group S), whereas a 0.5-mm oversized rasp was used in 36 hips (group M). The Japanese Orthopedic Association hip score and radiographic findings were evaluated, including cement mantle thickness, stress shielding, and cortical hypertrophy.

RESULTS

The Japanese Orthopedic Association hip score was significantly improved postoperatively with 100% of the implant survival rate in both groups when septic loosening was excluded. Radiographic assessment performed immediately postoperatively revealed that the cement mantle thickness was significantly larger in group M than group S in Gruen zone 1 but did not differ between groups in zones 2-7. Stress shielding was significantly more frequent in group M than group S at 2 years (P = .011), 5 years (P = .012), and ≥10 years postoperatively (P = .038). Cortical hypertrophy appeared in a time-dependent manner; however, the prevalence did not significantly differ between groups at final follow-up at a mean of 11.7 years (range 10-14 years) postoperatively.

CONCLUSIONS

The DCM-J stem achieved good clinical results in both groups. Stress shielding was significantly more frequent in THA using the 0.5-mm rasp than the 1.5-mm rasp, indicating that sufficient cement mantle room should be prepared for the cemented stem.

Prosthetic Neck Fracture in Exeter V40 Stems: A Report of Two Cases and Review of Literature

This report contains 2 acute fractures of the Exeter V40 stem with 2 different types of neck fracture, one at the subcapital level and another at the base of the neck. A review of relevant literature provides an insight into a similar pattern of failures reported in a certain subset of cases. We hypothesize that for high-BMI cases, attention to proper preoperative templating is mandatory. The operating surgeon should try to restore offset without having to use a long head in this subgroup of patients. We feel that trying to compensate for the offset with a long head may lead to high-stress concentration in the neck. This, in turn, may be responsible for the failure of the stem, as seen in the reported cases. We advocate, based on the literature, the need to recreate the offset carefully with as big a stem as possible to avoid these unique and rare complications. Reducing such failures may further improve the overall survivorship of the V40 Exeter stem.

Outcomes of the Exeter V40 cemented femoral stem at a minimum of ten years in a non-designer centre

Aims

The Exeter V40 cemented femoral stem was first introduced in 2000. The largest single-centre analysis of this implant to date was published in 2018 by Westerman et al. Excellent results were reported at a minimum of ten years for the first 540 cases performed at the designer centre in the Exeter NHS Trust, with stem survivorship of 96.8%. The aim of this current study is to report long-term outcomes and survivorship for the Exeter V40 stem in a non-designer centre.

Methods

All patients undergoing primary total hip arthroplasty using the Exeter V40 femoral stem between 1 January 2005 and 31 January 2010 were eligible for inclusion. Data were collected prospectively, with routine follow-up at six to 12 months, two years, five years, and ten years. Functional outcomes were assessed using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. Outcome measures included data on all components in situ beyond ten years, death occurring within ten years with components in situ, and all-cause revision surgery.

Results

A total of 829 stems in 745 patients were included in the dataset; 155 patients (20.8%) died within ten years, and of the remaining 664 stems, 648 stems (97.6%) remained in situ beyond ten years. For the 21 patients (2.5%) undergoing revision surgery, 16 femoral stems (1.9%) were revised and 18 acetabular components (2.2%) were revised. Indications for revision in order of decreasing frequency were infection (n = 6), pain (n = 6), aseptic component loosening (n = 3), periprosthetic fracture (n = 3), recurrent dislocation (n = 2), and noise production (ceramic-on-ceramic squeak) (n = 1). One patient was revised for aseptic stem loosening. The mean preoperative WOMAC score was 61 (SD 15.9) with a mean postoperative score of 20.4 (SD 19.3) (n = 732; 88.3%).

Conclusion

The Exeter V40 cemented femoral stem demonstrates excellent functional outcomes and survival when used in a high volume non-designer centre. Outcomes are comparable to those of its serially validated predecessor, the Exeter Universal stem.

Cite this article: Bone Jt Open 2020;1-12:743–748.

Achievement of optimal implant alignment using taper wedge stems with cup-first THA through the MIS antero-lateral approach

PURPOSE

Combined anteversion (CA) technique (stem-first procedure) has become generally accepted as an ideal means to achieve optimal CA value in THA. However, we hypothesized that CA technique for patients with various native femoral anteversions could pose a risk of anterior or posterior cup protrusion. In the present study, we examined whether it is possible to use the taper wedge stem to change the stem version to achieve optimal CA while avoiding cup protrusions with the cup-first procedure through minimally invasive (MIS) antero-lateral approach.

METHODS

Eighty-one patients underwent cup-first THA with a taper wedge stem. The acetabular cup was placed following the preoperative planning of the cup alignment to avoid anterior cup protrusions using CT-based navigation. Following the CA theory, anteversion of the taper wedge stem was changed to the target anteversion from the patient's native femoral anteversion. The native femoral anteversion, the change in version angle of the stem, postoperative CA and the length of anterior cup protrusions were evaluated in postoperative CT measurements.

RESULTS

The native femoral anteversion averaged 25.7° ± 8.9° (range 8°-45°). Cases with increased and decreased stem anteversion were observed in 42 hips (51.8%) and 33 hips (40.7%), respectively. The amount of increased and decreased version angles averaged 7.7° ± 4.8° (range 2°-21°) and 7.8° ± 5.1° (range 2°-20°), respectively. Postoperative CA values averaged 36.7° ± 3.4° (range 29.4°-44.2°) and anterior cup protrusion length averaged 2.0 mm ± 2.6 mm (0 ~ 8.8 mm) in axial view and 0.4 mm ± 1.0 mm (0 ~ 3.6 mm) in sagittal view. Anterior cup protrusion of more than 10 mm was not observed in any hips.

CONCLUSION

This procedure can be considered as an option to achieve optimal CA anteversion while avoiding anterior cup protrusion in THA.