Mortality After Revision Total Hip Arthroplasty

Exploring needs, barriers to, and facilitators of rehabilitation exercise following revision hip replacement - A grounded theory study

PURPOSE

Evidence on rehabilitation after revision total hip replacement (THR) is inadequate and development of rehabilitation interventions is warranted. Even so, little is known about patients' experiences with revision THR rehabilitation. This study aimed to explore patients' rehabilitation exercise experiences after revision THR.

MATERIALS AND METHODS

Using constructivist grounded theory, we conducted semi-structured qualitative interviews with twelve patients with completed or almost completed rehabilitation exercise after revision THR. Data collection and analysis were a constant comparative process conducted in three phases; initial, focused, and theoretical.

FINDINGS

From the data, we generated a substantial theory of the participant's circumstances and ability to integrate rehabilitation exercise into their everyday life after revision THR. Four categories were constructed based on patients' experiences in different contexts: hesitance, fear avoidance, self-commitment, and fidelity.

CONCLUSIONS

This study highlighted that patients' expectations, past experiences, attitudes, trusts, and circumstances interact to influence engagement and adherence to rehabilitation exercise and described four categories relating to the integration of revision THR rehabilitation exercise into their everyday life. Clinicians should be aware of and account for these categories during rehabilitation exercise. Tailored individual rehabilitation exercise interventions and clinician approaches to optimize engagement and adherence are needed among patients with revision THR.

Preoperative Three-Dimensional Planning Using Computed Tomography Improves Screw Placement in Patients Undergoing Acetabular Revision Surgery

Background

Stable fixation of joint replacement implants is essential to achieve osseointegration in uncemented implants. In acetabular revisions, screws often need to be utilized in quadrants other than the historically so-called "safe" zones to attain sufficient stability. The primary aim of this study was to determine whether preoperative three-dimensional (3D) planning for acetabular revision surgery influences screw length, specifically in the superior pubic ramus (SPR).

Methods

Between March 2017 and December 2021, 20 patients underwent preoperative two-dimensional (2D) planning (2D group), and 30 patients underwent 3D planning following the implementation of a new 3D planning software into clinical practice in September 2019 (3D group). Two observers, blinded to the groups, measured the total screw length, screw penetration depth, and cup position on available postoperative computed tomography examinations. For statistical comparisons, the mean measurement from the 2 observers was used.

Results

The median total screw lengths in the SPR were 16 mm in the 2D group and 25 mm in the 3D group (P = .004) and 40.5 mm compared with 50.5 mm in the ilium (P = .019). Median screw penetration depths in the SPR were 0 mm in the 2D group and 1.25 mm in the 3D group (P = .049).

Conclusion

Longer screws were used in the SPR and ilium when preoperative 3D planning was conducted. Due to the study design, we were not able to evaluate whether longer screws lead to better fixation. Further studies are needed to elucidate this question.

Permissive Weight Bearing in Patients With Surgically Treated Periprosthetic Femoral Fractures Around Total Hip Arthroplasty: A Scoping Review

Periprosthetic femoral fractures (PPFF) around total hip arthroplasty (THA) are one of the leading causes of hip revision. High mortality rates are observed after revision in case of PPFF around THA. To modify risk factors, early postoperative mobilization is necessary. Permissive weight bearing (PWB) is designed to optimize clinical recovery in aftercare. This study aimed to perform a scoping review to summarize the current available evidence on postoperative weight bearing in late PPFF around THA and the implementation of PWB in aftercare. A systematic search was performed on the Cochrane Library, Web of Science, Ovid MEDLINE, EMBASE, and CINAHL databases on January 26th, 2023. Articles were screened in two stages by two independent reviewers. Studies describing adult patients with a history of primary THA who were surgically treated for late PPFF and mentioning prescribed postoperative weight-bearing protocols with relevant outcome measures were included. Seven studies were included, reporting data on 22 patients (age range 47-97 years, BMI range 19-32 kg/m2, ASA classification range 2-3). No studies used PWB in aftercare. The non-weight-bearing group showed no complications. The restricted weight-bearing group had one death and one implant failure. The full weight-bearing group experienced one deep infection and one plate removal because of impingement. The main finding was that, after an extensive systematic search, no articles could be included focusing on PWB in patients with a late PPFF after THA. Addressing this gap in the literature is essential to advancing the understanding of postoperative weight-bearing protocols and PWB for late PPFF around THA.

Risk of blood transfusion following total hip arthroplasty: A national database study from 367,894 patients

Purpose

A growing elderly population in the United States coupled with improvement in surgical techniques have resulted in more elderly individuals undergoing total hip arthroplasty (THA). As such, risk factors associated with increased risk of blood transfusion following THA, which has been linked to various detrimental outcomes, must be better understood. This study aims to identify co-morbidities associated with blood transfusion following THA.

Methods

Using the Nationwide Inpatient Sample (NIS) database, we selected patients that received a THA from 2016 to 2019 using ICD-10CMP codes. Patients were classified into a "blood transfusion" or "no transfusion" groups and data pertaining to demographics, co-morbidities, and events during hospital stays were compared between the groups.

Results

Our study dataset included 367,894 patients from the NIS database that underwent a THA from 2016 to 2019. 12,900 (3.5 %) patients received a blood transfusion after their THA and were classified as "blood transfusion group." The remaining 354,994 patients were classified as the "no transfusion group." Elective admission was found to decrease the odds of a blood transfusion following a THA (compared to nonelective THA: odd's ratio 0.283; p value < 0.001). Multivariate analysis demonstrated sickle cell disease, liver cirrhosis, and dialysis exhibited the greatest increase in odds of blood transfusion after a THA by 4.81- (p < 0.001), 3.02- (p < 0.001), and 2.22-fold (p < 0.001), respectively. Looking at patient demographics, male sex increased odds of postoperative transfusion by 1.99 (p < 0.001) while Caucasian ethnicity decreased odds of postoperative transfusion by 0.65 (p < 0.001).

Conclusion

Blood transfusion has a low occurrence in the early post-operative period following THA (3.6 % of patients). Sickle cell disease, liver cirrhosis, dialysis, SLE, and heart pathologies were the comorbidities found to be most significantly associated with an increased risk of blood transfusion after a THA. Additionally, both mortality and non-elective admissions were significantly more prevalent in the "blood transfusion" group.

Patient-Reported Outcomes Following Revision Total Hip Arthroplasty Demonstrate Less Improvement and Significantly Higher Rates of Worsening Compared to Primaries

BACKGROUND

Patient-reported outcome measures (PROMs) provide the patient's perspective following total hip arthroplasty (THA), although differences between primary THA (pTHA) and revision THA (rTHA) remain unclear. Thus, we compared the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W) in pTHA and rTHA patients.

METHODS

Data from 2,159 patients (1,995 pTHAs/164 rTHAs) who had completed Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF10a), PROMIS Global-Mental, or PROMIS Global-Physical questionnaires were analyzed. The PROMs and MCID-I/MCID-W rates were compared using statistical tests and multivariate logistic regressions.

RESULTS

Compared to the pTHA group, the rTHA group had lower rates of improvement and higher rates of worsening for almost all PROMs, including HOOS-PS (MCID-I: 54 versus 84%, P < .001; MCID-W: 24 versus 4.4%, P < .001), PF10a (MCID-I: 44 versus 73%, P < .001; MCID-W: 22 versus 5.9%, P < .001), PROMIS Global-Mental (MCID-W: 42 versus 28%, P < .001), and PROMIS Global-Physical (MCID-I: 41 versus 68%, P < .001; MCID-W: 26 versus 11%, P < .001). Odds ratios supported rates of worsening following revision for the HOOS-PS (Odds Ratio (OR): 8.25, 95% Confidence Interval (CI): 5.62 to 12.4, P < .001), PF10a (OR: 8.34, 95% CI: 5.63 to 12.6, P < .001), PROMIS Global-Mental (OR: 2.16, 95% CI: 1.41 to 3.34, P < .001), and PROMIS Global-Physical (OR: 3.69, 95% CI: 2.46 to 5.62, P < .001).

CONCLUSION

Patients reported higher rates of worsening and lower rates of improvement following rTHA than pTHA, with significantly less score improvement and lower postoperative scores for all PROMs after revision. Most patients reported improvements following pTHA, with few worsening postoperatively.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

What enhances the in-hospital mortality following total hip arthroplasty? A national inpatient sample-based study

PURPOSE

With prolonged life expectancy and advancements in prosthetic designs, the proportion of patients belonging to diverse age groups undergoing total hip arthroplasty (THA) has progressively increased. In this context, the details regarding risk factors associated with mortality after THA, and its prevalence need to be clearly understood. This study sought to identify the possible co-morbidities associated with post-THA mortality.

METHODS

Based on Nationwide Inpatient Sample (NIS) database, patients undergoing THA from 2016 to 2019 (using ICD-10CMP) were identified. The included cohort was stratified into two groups: "early mortality" and "no mortality" groups. The data regarding patients' demographics, co-morbidities, and associated complications were compared between the groups.

RESULTS

Overall, 337,249 patients underwent THA, among whom, 332 (0.1%) died during their hospital admission ("early mortality" group). The remaining patients were included under "no mortality" group (336,917 patients). There was significantly higher mortality in the patients, who underwent emergent THA (as compared with elective THA: odd's ratio 0.075; p < 0.001). Based on multivariate analysis, presence of liver cirrhosis, chronic kidney disease (CKD) and previous history of organ transplant increased the odds of mortality {odds ratio [Exp (B)]} after THA by 4.66- (p < 0.001), 2.37-fold (p < 0.001) and 1.91-fold (p = 0.04), respectively. Among post-THA complications, acute renal failure (ARF), pulmonary embolism (PE), pneumonia, myocardial infarction (MI), and prosthetic dislocation increased the odds of post-THA mortality by 20.64-fold (p < 0.001), 19.35-fold (p < 0.001), 8.21-fold (p < 0.001), 2.71-fold (p = 0.05) and 2.54-fold (p < 0.001), respectively.

CONCLUSION

THA is a safe surgery with low mortality rate during early post-operative period. Cirrhosis, CKD, and previous history of organ transplant were the most common co-morbidities associated with post-THA mortality. Among post-operative complications, ARF, PE, pneumonia, MI, and prosthetic dislocation substantially enhanced the odds of post-THA mortality.

Defining Clinically Meaningful Subgroups for Risk Stratification in Patients Undergoing Revision Total Hip Arthroplasty: A Combined Unsupervised and Supervised Machine Learning Approach

BACKGROUND

Studies developing predictive models from large datasets to risk-stratify patients under going revision total hip arthroplasties (rTHAs) are limited. We used machine learning (ML) to stratify patients undergoing rTHA into risk-based subgroups.

METHODS

We retrospectively identified 7,425 patients who underwent rTHA from a national database. An unsupervised random forest algorithm was used to partition patients into high-risk and low-risk strata based on similarities in rates of mortality, reoperation, and 25 other postoperative complications. A risk calculator was produced using a supervised ML algorithm to identify high-risk patients based on preoperative parameters.

RESULTS

There were 3,135 and 4,290 patients identified in the high-risk and low-risk subgroups, respectively. Each group significantly differed by rate of 30-day mortalities, unplanned reoperations/readmissions, routine discharges, and hospital lengths of stay (P < .05). An Extreme Gradient Boosting algorithm identified preoperative platelets < 200, hematocrit > 35 or < 20, increasing age, albumin < 3, international normalized ratio > 2, body mass index > 35, American Society of Anesthesia class ≥ 3, blood urea nitrogen > 50 or < 30, creatinine > 1.5, diagnosis of hypertension or coagulopathy, and revision for periprosthetic fracture and infection as predictors of high risk.

CONCLUSION

Clinically meaningful risk strata in patients undergoing rTHA were identified using an ML clustering approach. Preoperative labs, demographics, and surgical indications have the greatest impact on differentiating high versus low risk.

LEVEL OF EVIDENCE

III.

Increased mortality after total hip prosthetic joint infection is mainly caused by the comorbidities rather than the infection itself

BACKGROUND AND PURPOSE

Periprosthetic joint infection (PJI) is a feared complication of arthroplasty surgery. There is controversy as to whether PJI also correlates with increased mortality. Our aim was to investigate in a nationwide cohort if PJI is an independent risk factor for dying.

PATIENTS AND METHODS

We performed a retrospective cohort study based on data from the Swedish Hip Arthroplasty Register (SHAR). All patients with a revision THA performed between 1998 and 2017 were included. The outcome is mortality; exposure is PJI according to SHAR. The control group was study participants who underwent aseptic revision. Confounders were age, sex, diagnosis, and comorbidity according to the Elixhauser index. The outcome was analyzed with a Cox proportional hazards model.

RESULTS

4,943 PJI revisions and 12,529 non-infected revisions were included in the analysis. The median follow-up time was 4.1 years. In the PJI group, 1,972 patients died and in the control group, 4,512. The incidence rate ratio was 1.19 (95% confidence interval [CI] 1.13-1.25), the crude hazard ratio (HR) 1.19 (CI 1.13-1.25), and the adjusted HR 1.05 (CI 0.99-1.12) for the exposed versus the unexposed group. The strongest confounder was comorbidity.

CONCLUSION

The increased mortality risk after revision due to PJI is mainly caused by the comorbidity of the patient, rather than by the infection itself.

Revision Total Hip Arthroplasty in Octogenarians Compared with Septuagenarians: Is There a Real Difference?

BACKGROUND

The increasing frequency of total hip arthroplasty (THA) as well as an aging population indicate that the need for revision THA will continue to grow, especially in older and potentially medically complex patients. The purpose of this study was to compare THA revision indications, perioperative complications, and readmissions between octogenarian and septuagenarian patients. We hypothesized that patients aged 80 to 89 years would have similar outcomes to patients aged 70 to 79 years undergoing revision THA.

METHODS

Between 2008 and 2019, 572 revision THAs were performed at a single tertiary care hospital. Patients were stratified by age group: 70 to 79 years (n = 407) and 80 to 89 years (n = 165). Indication for revision, perioperative medical complications, and 90-day readmission were identified for each patient. Chi-square tests and t-tests were used to compare the groups. Logistic regression was used to assess medical complications and readmissions.

RESULTS

Aseptic loosening was a more common indication for revision in patients aged 70 to 79 years (33.4% versus 26.7%; p < 0.001), while periprosthetic fracture was a more common indication for revision in those aged 80 to 89 years (30.9% versus 13.0%). Perioperative medical complications occurred more often in octogenarians (10.9% versus 3.0%; p = 0.001), with arrythmia being the most common type. Patients aged 80 to 89 years were at increased risk for medical complications (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.5 to 7.3; p = 0.004) and readmission (OR, 3.2; 95% CI, 1.7 to 6.3; p < 0.001) when adjusting for body mass index (BMI) and indication for revision. Octogenarians had a higher rate of reoperation following first-time revision than septuagenarians (10.3% versus 4.2%, p = 0.009).

CONCLUSIONS

Octogenarians more commonly underwent revision THA for periprosthetic fracture and had higher rates of perioperative medical complications, 90-day readmissions, and reoperations than septuagenarians. Such findings should be considered when counseling patients on both primary and revision THAs.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Understanding the 30-day mortality burden after revision total hip arthroplasty

BACKGROUND

Revision total hip arthroplasty (THA) is a challenging procedure that burdens the healthcare system. Despite being associated with worse outcomes relative to its primary counterpart, postoperative mortality after revision THA remains ill-defined. The present study aimed to (1) establish the overall 30-day mortality rate after revision THA and (2) explore the mortality rate stratified by age, comorbidity burden, and aseptic versus septic failure.

METHODS

The American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) database was retrospectively reviewed for all patients who underwent revision THA from 2011 to 2019. A total of 23,501 patients were identified and grouped into mortality (n = 161) and mortality-free (n = 23,340) cohorts. Patient demographics, comorbidities, and aseptic/septic failure were evaluated.

RESULTS

The overall 30-day mortality was 0.69%. The mortality rate by age group (normalised per 1000 patients) was 0 (18-39 years [Y]), 0.67 (40-49 Y), 1.10 (50-59 Y), 2.58 (60-69 Y), 6.15 (70-79 Y) 19.32 (80-89 Y), and 58.22 (90+Y) (p < 0.001). The mortality rate by ASA classification (normalised per 1000 patients) was 0 (ASA I), 1.47 (ASA II), 6.94 (ASA III), 45.42 (ASA IV), and 200 (ASA V) (p < 0.001). The 30-day mortality rate for the septic and aseptic cohorts was 1.03% and 0.65%, respectively (p = 0.038). CCI scores (p < 0.001), diabetes (p < 0.001), systematic sepsis (p < 0.001), poor functional status (p < 0.001), BMI < 24.9 kg/m2 (p < 0.001), and dirty/infected wounds (p < 0.001) were all associated with increased mortality risk.

CONCLUSIONS

1 in 145 patients will suffer mortality during the 30 days after revision THA. PJI-related revision THA was associated with 1.5-fold increase in 30-day mortality rate compared to its aseptic counterpart. Certain patient determinants and baseline comorbidities, as measured by ASA and CCI scores, were associated with higher 30-day mortality rates. Therefore, it is imperative to identify such risk factors and implement perioperative patient optimisation pathways to mitigate the risk among vulnerable patients.

Hepatitis C Is Associated With Higher Short-Term Complication Rates After Initial Aseptic and Septic Revision Total Hip Arthroplasty: A Matched Cohort Study

BACKGROUND

It is unclear if hepatitis C virus (HCV) negatively impacts outcomes of revision total hip arthroplasty (rTHA). The purpose of this study is to trend recent rTHA utilization in patients who have HCV and compare postoperative complication rates versus a matched cohort.

METHODS

All patients who underwent rTHA were retrospectively identified in a national database. Patients who had HCV (n = 1,746) were matched 1:3 with a matching group (n = 5,238) for age, gender, and several comorbidities. Cochran-Armitage tests were used to analyze trends in the annual proportion of rTHA performed in patients who had HCV from 2010 to 2019. Rates of 90-day medical and prosthesis-related complications within 2 years postoperatively were compared with multivariable logistic regressions.

RESULTS

The annual proportion of rTHA performed in patients who had HCV significantly increased from 2010 to 2019 (P < .001). Patients who had HCV exhibited significantly higher rates of acute kidney injuries (7.6% versus 4.4%; odds ratio [OR] 1.50), transfusions (20.6% versus 14.6%; OR 1.38), and re-revisions for prosthetic joint infection (10.9% versus 6.5%; OR 1.73). In subgroup analyses, rates of re-revision for prosthetic joint infection after initial aseptic rTHA (7.1% versus 3.8%; OR 1.82) and periprosthetic fracture after initial septic rTHA (4.5% versus 1.6%; OR 2.77) were significantly higher in the HCV cohort.

CONCLUSION

Similar to primary THA, patients who have HCV exhibit significantly increased complication rates after rTHA. With growing utilization in recent years, these data suggest that this population will comprise an increasingly larger proportion of rTHA procedures performed in the coming years.

Sarcopenia Is Associated with an Increased Risk of Postoperative Complications Following Total Hip Arthroplasty for Osteoarthritis

Sarcopenia is a state of catabolic muscle wasting prevalent in geriatric patients. Likewise, osteoarthritis is an age-related musculoskeletal disease affecting patients with similar demographics. Late-stage hip osteoarthritis is often treated with total hip arthroplasty (THA). As sarcopenia influences the surgical outcomes, this study aimed to assess the impact of sarcopenia on the outcomes of THA. A 1:3 matched case-control study of sarcopenic to control patients was performed using a large national database. In total, 3992 patients were analyzed. Sarcopenic patients undergoing THA were more likely to experience dislocation (odds ratio (OR) = 2.19, 95% confidence interval (CI) 1.21-3.91) within 1 year of THA. Furthermore, sarcopenic patients had higher urinary tract infection rates (OR = 1.79, CI 1.32-2.42) and a greater risk of 90-day hospital readmission (hazard ratio (HR) = 1.39, CI 1.10-1.77). Sarcopenic patients experienced more falls (OR = 1.62, CI 1.10-2.39) and fragility fractures (OR = 1.77, CI 1.34-2.31). Similarly, sarcopenic patients had higher day of surgery costs (USD 13,534 vs. USD 10,504) and 90-day costs (USD 17,139 vs. USD 13,394) compared with the controls. Ultimately, sarcopenic patients undergoing THA experience higher rates of postoperative complications and incur greater medical costs. Given the potential risks, orthopedic surgeons may consider treating or reducing the severity of sarcopenia before surgery.

[Postoperative outcomes and survival rates after aseptic revision total hip arthroplasty : What can patients expect from revision surgery?]

BACKGROUND

In 2020, more than 14,000 aseptic revision procedures for total hip arthroplasty (THA) were registered in Germany. Patient expectations of revision hip arthroplasty are not substantially different from expectations of primary hip replacement.

OUTCOME

However, revision surgery is associated with increased complication rates and a higher proportion of dissatisfied patients. In particular, poorer postoperative function and mobility as well as increased pain levels following revision THA have been described compared to the outcome after primary THA. Quality of life and return-to-work can also be impaired.

SURVIVAL RATE

Implant survival is influenced by age, BMI, and comorbidities of the patients, but also by the size and complexity of bone defects, the extent of periprosthetic soft tissue compromise and the choice of revision implant(s). In addition, the number of previous revision surgeries inversely correlates with the survival rates. Previous revisions have been shown to be associated with increased risks of aseptic loosening, instability and periprosthetic infection.

Diagnosis and Detection of Subtle Aseptic Loosening in Total Hip Arthroplasty

Aseptic loosening is a common cause of revision total hip arthroplasty (rTHA), and with the rising number of primary THAs, revisions for aseptic loosening represent a significant burden for arthroplasty surgeons. Aseptic loosening remains a diagnostic and management challenge. Loosening can occur as a result of inadequate initial fixation, mechanical loss of fixation over time, or a biological loss of fixation over time. However, in most cases, etiology is multifactorial, involving all 3 factors. The diagnosis of aseptic loosening involves a careful history, focused clinical exam, and thorough evaluation of imaging using several diagnostic modalities. The careful evaluation of serial radiographs remains the cornerstone of diagnosis with additional input from advanced imaging modalities such as FDG-PET, DEXA, MRI, and several others, each offering unique advantages and disadvantages. In certain patients, history and physical exam might be the only initial obvious signs of loosening, and thus, unexplained continuous pain augmented by imaging findings serves as an indication for revision surgery.

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.