Epidemiology of total hip arthroplasty: demographics, comorbidities and outcomes

Assessing osteoporosis screening compliance in total joint surgery: a retrospective chart review

CONTEXT

Osteoporosis is a prevalent concern, particularly among aging populations, leading to increased risk of fractures, including those related to hip and knee arthroplasty procedures. Screening for osteoporosis, especially with dual X-ray absorptiometry (DXA) scans, is crucial for early detection and management.

OBJECTIVES

This study aimed to assess adherence to osteoporosis screening guidelines among patients aged 65 and older undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) within a single health network. Factors influencing screening adherence were also explored.

METHODS

A retrospective chart review of 2,160 patients undergoing elective THA or TKA between January 2019 and January 2023 was conducted. Demographic data, osteoporosis screening status, and occurrence of periprosthetic fractures were analyzed. Statistical analysis included descriptive statistics and chi-square tests.

RESULTS

Only 24.1 % of eligible patients underwent a DXA scan prior to surgery. Females were more likely to undergo screening than males, and race was also associated with screening status. A total of 45 periprosthetic fractures were identified, with no significant correlation between osteoporosis status, DXA screening, and fracture occurrence.

CONCLUSIONS

Adherence to osteoporosis screening guidelines among geriatric patients undergoing elective total joint arthroplasty remains low within the studied health network. Despite the lack of correlation between screening and fracture occurrence in this study, the importance of screening and potential optimization in high-risk patients is emphasized. Further research is needed to assess outcomes associated with different care pathways in bone health screening and management for elective geriatric total joint patients.

Minimum 10-Year Follow-Up of Vitamin-E Diffused Highly Crosslinked Polyethylene Liners in Total Hip Arthroplasty: Comparative Evaluation from a Prospective, International, Multicenter Cohort Study

BACKGROUND

Total hip arthroplasty (THA) is a proven, effective treatment for end-stage osteoarthritis. The success of THA is due in part to highly crosslinked (XL) polyethylene implants. In 2007, a new generation of polyethylene liners entered clinical use. The new liners infused polyethylene with vitamin E (EP). The EP liner was hypothesized to prevent the loss of mechanical properties caused by oxidation, extending the lifetime of the implant. This international prospective study aimed to quantify the clinical outcomes of a 977-patient cohort receiving EP and XL liners 10 years after surgery.

METHODS

The prospective cohort study began in 2007, including eight countries and seventeen centers. The final cohort included 977 patients (EP liner: n = 520; XL liner: n = 457). Patients were followed preoperatively, postoperatively, and at 1, 3, 5, 7, and 10 years. Each follow-up visit involved clinical evaluation, radiography, and survey collection. Demographics and revisions were also recorded. Mann-Whitney U tests were used to evaluate statistical differences.

RESULTS

At ten years following surgery, 534 patients were eligible for follow-up. Of those eligible, 352 patients returned for clinical evaluation (65.9% eligible; 36.0% overall). No statistical differences were found (P > 0.05) in the demographics of the followed-up cohort. The linear wear rates were 0.00338 mm/year for XL liners and 0.0236 mm/year for EP liners using individual regression (P < 0.0001). No significant difference was observed in wear rates using cohort regression. Similarly, surveys suggested no significant outcomes between the EP and XL liner cohorts. The overall incidence of revision was 2.3% for EP and 2.0% for XL liners.

CONCLUSION

The EP liner demonstrated significantly lower wear than its XL counterparts at 10-years after implantation. Results are promising, as vitamin E polyethylene may improve the lifetime performance of THA implants and ensure arthroplasty innovations reflect the changing patient population.

The Sacroiliac Joint Fusion Patient Population and Its Prevalence of Total Hip Arthroplasty

INTRODUCTION

The prevalence of sacroiliac joint (SIJ) pathology generating lower back pain is increasing, often requiring SI joint fusion in refractory cases. Similarly, total hip arthroplasty (THA) is an increasing procedure in the older growing population. Prior SIJ fusion in patients undergoing THA has increased hip dislocation. This study aims to determine the prevalence of preexisting THA in SIJ fusion patients at our institution.

METHODS

After institutional review board approval, we completed a retrospective review of consecutive SIJ fusion cases performed by fellowship-trained orthopaedic spine surgeons between October 2019 and June 2022. The senior surgeon reviewed pelvis radiographs to determine whether a THA was present. Patient demographics, surgical history, SIJ fusion date, and laterality information from study participants' medical records were collected and analyzed.

RESULTS

We screened 157 consecutive cases and excluded 45 not meeting the inclusion criteria. One hundred twelve radiographs were reviewed, with seven additional patients excluded. The final analysis consisted of 105 patients (33M:72F). The mean age was 50.4 ± 13.8 years, and the mean body mass index was 29.1 ± 6.1 kg/m 2 . SIJ fusion laterality included 51 right (48.6%), 44 left (41.9%), and 10 bilateral (9.5%). One patient (0.95%) had a preexisting right THA, and two patients (1.9%) underwent ipsilateral THA after SIJ fusion.

CONCLUSIONS

This study demonstrated a low prevalence (0.95%) of preexisting THA in SIJ fusion patients at our institution, similar to the THA prevalence of the total US population. Additional research is needed to determine the outcomes of patients with preexisting THA undergoing SIJ fusion.

Patient Demographic Factors Affect Response Rates to Patient-Reported Outcome Measures for Total Hip Arthroplasty Patients

BACKGROUND

The Hip Disability and Osteoarthritis Outcome Score (HOOS JR) is a widely used patient-reported outcome measures questionnaire for total hip arthroplasty (THA). However, not all patients choose to complete HOOS JR, and thus, a subset of the THA population may be underrepresented. This study aims to investigate the association between patient demographic factors and HOOS JR response rates.

METHODS

This was a retrospective cohort study of adult, English-speaking patients who underwent primary THA by a fellowship-trained arthroplasty surgeon between 2017 and 2023 at a single, high-volume academic institution. The HOOS JR completion status-complete or incomplete-was recorded for each patient within 90 days of surgery. Standard statistical analyses were performed to assess completion against multiple patient demographic factors.

RESULTS

Of the 2,908 total patients, 2,112 (72.6%) had complete and 796 (27.4%) had incomplete HOOS JR questionnaires. Multivariate analysis yielded statistical significance (P < .05) for the distribution of patient age, race, insurance, marital status, and income quartile with respect to questionnaire completion. Patient sex or religion did not affect response rates. Failure to complete HOOS JR (all P < .001) was associated with patients aged 18 to 39 (59.8%), who identified as Black (36.4%) or "other" race (39.6%), were never married (38%), and were in the lower half income quartiles (43.9%, 35.9%) when compared to the overall incomplete rate.

CONCLUSIONS

Multiple patient demographic factors may affect the HOOS JR response rate. Overall, our analyses suggest that older patients who identify as White and are of higher socioeconomic status are more likely to participate in the questionnaire. Efforts should focus on capturing patient groups less likely to participate to elucidate more generalizable trends in arthroplasty outcomes.

Medicaid Reimbursement for Total Hip and Knee Arthroplasty: A State-by-State Analysis Compared with Medicare

BACKGROUND

Medicare reimbursement for arthroplasty procedures has been declining, but little has been reported on Medicaid reimbursement. We sought to determine Medicaid reimbursement rates using state Medicaid data for nine arthroplasty procedure codes and compare them to Medicare rates.

METHODS

The Centers for Medicare & Medicaid Services physician fee schedule was used to collect Medicare reimbursement rates, and state Medicaid fee schedules were accessed to collect Medicaid rates for nine procedures encompassing primary and revision hip and knee arthroplasty surgery. State Medicare and Medicaid rates were compared to determine the mean dollar difference and dollar difference per relative value unit (RVU). A cost of living adjustment was performed using the Medicare Wage Index for each state. Coefficients of variation were calculated for each state to determine overall variability between the two systems.

RESULTS

The mean reimbursement rates for Medicaid were lower for eight of the nine codes used in the study. Medicaid reimbursed physicians an average of 11.3% less overall and 23.1% less when adjusted for cost of living. The amount of variability in the Medicare rates was low with a consistent coefficient of variation of 0.06, but was higher in the Medicaid rates with a range of 0.26 to 0.29 in the unadjusted rates and 0.34 to 0.37 in the adjusted rates. There was a mean $6.73 decreased reimbursement per RVU for Medicaid procedures.

CONCLUSION

For the most common arthroplasty procedures, Medicaid reimbursed physicians less than Medicare on average. Medicaid also demonstrated increased variability when compared to Medicare rates between states.

Usage of Tranexamic Acid for Total Hip Arthroplasty: A Matched Cohort Analysis of 144,344 Patients

Background: The literature is inconclusive regarding the potential complications of tranexamic acid (TXA), an antifibrinolytic drug, for total hip arthroplasty (THA). The purpose of this study is to compare complication rates and patient outcomes between THA patients administered TXA vs. THA patients not administered TXA. Methods: The TriNetX Research network was utilized to generate a cohort of adult patients who underwent THA between 2003 and 2024. These patients were categorized into two subgroups for the retrospective analysis: (1) patients who received TXA 24 h prior to THA (TXA), and (2) patients who did not receive TXA 24 h prior to total hip arthroplasty (no-TXA). The follow-up period was 30 and 90 days. Results: At 30 days following THA, the TXA patients had a reduced risk of transfusion (risk ratio (RR): 0.412; 95% confidence intervals (CI): 0.374, 0.453), reduced risk of DVT (RR: 0.856; CI: 0.768, 0.953), reduced risk of joint infection (RR: 0.808; CI: 0.710, 0.920), but a higher rate of periprosthetic fracture (RR: 1.234; CI: 1.065, 1.429) compared to patients who did not receive TXA. At 90 days following THA, TXA patients had a reduced risk of transfusion (RR: 0.446; CI: 0.408, 0.487), DVT (RR: 0.847; CI: 0.776, 0.924), and periprosthetic joint infection (RR: 0.894; CI: 0.815, 0.982) compared to patients who did not receive TXA. Patients who received TXA had higher rates of periprosthetic fracture (RR: 1.219; CI: 1.088, 1.365), acute postoperative anemia (RR: 1.222; CI: 1.171, 1.276), deep surgical site infection (SSI) (RR: 1.706; CI: 1.117, 2.605), and superficial SSI (RR: 1.950; CI: 1.567, 2.428) compared to patients who did not receive TXA. Conclusions: Patients receiving TXA prior to THA exhibited significantly reduced the prevalence of blood transfusions, DVT, and periprosthetic joint infection following THA. However, superficial SSI and periprosthetic fracture were seen with higher rates in the TXA cohort than in the no-TXA cohort.

Mid-term outcomes of total hip arthroplasty in patients younger than 30 years

INTRODUCTION

Total hip arthroplasty (THA) has predominantly been utilized to treat older patients with primary osteoarthritis. However, recent improvements in surgical technique and implant materials have increased implant longevity, making THA a viable option for younger patients (< 30 years old). While trend analyses indicate an expanding utilization of THA in younger patients with non-OA diagnoses, current data on mid- and long-term THA outcomes in this population are limited. This study aims to describe the demographics, perioperative data, and implant survivorship of patients younger than 30 years undergoing THA.

METHODS

A retrospective study across two large urban academic medical institutions identified 135 patients aged < 30 years who underwent 155 primary THAs between 2012 and 2017, with up to 10-year clinical follow-up. Baseline demographics, surgical indications, intraoperative details, and postoperative outcomes were analyzed.

RESULTS

The mean age at surgery was 24.9 years (range 18-29). Osteonecrosis of the femoral head (55.5%), developmental hip dysplasia (28.3%), and arthritis (15.5%) were the primary indications. Most surgeries utilized the posterior approach (64.5%), manual technique (65.8%), and Ceramic-on-Polyethylene articulation (71.6%). Seven patients (4.5%) were readmitted within 90-days of surgery, including three non-orthopedic-related readmissions (1.9%) and four orthopedic-related readmissions (2.6%). Dislocations were reported in two patients (1.3%). There were six all-cause revisions (3.9%), four aseptic (2.6%) and two septic (1.3%). Kaplan-Meier analysis showed 10-year survival from implant retaining reoperation was 98.7%, 10-year survival from all-cause revision was 96.1%, and 10-year survival from aseptic revision was 97.4%.

CONCLUSION

With a 10-year aseptic implant survivorship rate of 97.4%, THA is a reliable surgical intervention for patients younger than 30 years of age who have severe hip pathology. Further studies are warranted for a more comprehensive understanding of mid- and long-term survivorship risk factors in this demanding population, facilitating improved risk assessment and informed surgical decisions.

Etiology, Outcomes, and Complications of Total Hip Arthroplasty in Younger Patients: A Nationwide Big Data Analysis

Background: This study investigates the rising trend of total hip arthroplasty (THA) in patients under 55 years old, commonly referred to as "younger" THA patients. Traditionally a procedure for older adults with osteoarthritis, THA is increasingly performed on younger patients. Methods: Using data from the Nationwide Inpatient Sample (NIS) from 2016 to 2019, we analyze the factors driving this trend, including the causes of hip issues, patient characteristics, and coexisting medical conditions. The study examines in-hospital mortality, length of stay, post-surgical complications, and hospitalization costs for 231,630 THA patients aged 18-54.9, identified using ICD-10 codes. Results: Statistical analysis revealed that younger patients (aged 18-34.9) had higher rates of chronic anemia, inflammatory bowel disease, sickle cell disorders, connective tissue disorders, and coagulation defects compared to patients aged 35-44.9 and 45-54.9. They also experienced the longest hospital stays (2.08 days) and highest costs ($70,540). Significant odds ratios were found for sickle cell disorders (36.078), coagulation defects (1.566), inflammatory bowel disease (2.582), connective tissue disorders (11.727), hip dislocation (3.447), and blood transfusion (1.488) in younger patients compared to other THA patients. Conclusions: Comprehensive analysis of these unique needs is crucial for optimizing care, tailoring treatment, managing co-existing conditions, and personalizing recovery strategies to improve outcomes and quality of life for younger THA patients.

Total Hip Arthroplasty Outcomes in Patients with Gout: A Retrospective Analysis of Matched Large Cohorts

Background

Gout is the most prevalent form of inflammatory arthritis in the world. Total hip arthroplasty (THA) has emerged as a widely sought-after and highly effective surgical procedure for advanced hip diseases. However, there is a lack of research on the impact of gout on primary THA outcomes in large cohorts. This study aimed to address this gap by primarily investigating complications following THA in patients with or without gout.

Methods

Patients with records of gout in the 2 years leading up to their primary THA and who also have at least 2 years of follow-up were identified using a national insurance database and compared to a 5:1 matched control. A total of 32,466 patients with gout and 161,514 patients without gout undergoing THA were identified. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. In addition, 90-day emergency department (ED) visits and inpatient readmission were also documented.

Results

Patients with gout demonstrated higher rates of medical complications including deep vein thrombosis, transfusion, acute kidney injury, and urinary tract infection than non-gout patients (p < 0.001). Gout patients also showed higher rates of pulmonary embolism (p = 0.017). Increased incidences of surgical complications were identified in gout patients, specifically wound complications and periprosthetic joint infection (p < 0.001). There was an increased risk of revision for gout patients up to 90 days (p = 0.003), 1 year (p = 0.027), and 2 years (p = 0.039). There was also an increased risk of dislocation for gout patients up to 90 days (p = 0.022) and 1 year (p = 0.047), but not at 2 years. No significant difference was observed in aseptic loosening or periprosthetic fracture. Additionally, gout patients also demonstrated a higher likelihood of 90-day ED visits and readmission (p < 0.001).

Conclusions

Primary THA in gout patients is associated with increased risks of multiple medical and surgical complications. Our findings provide insights into the planning and expectation of THA for patients with gout. These insights have the potential to benefit the decision-making process for gout patients considering THA.

Risk Factors for Perioperative Nerve Injury Related to Total Hip Arthroplasty

Background

Nerve injury following total hip arthroplasty (THA) is a rare but serious adverse event. While prior studies have reported risk factors for nerve injury related to THA, they are limited to institutional data or small sample sizes. The current study aimed to leverage a large, national database to assess independent risk factors for sustaining nerve injury with THA.

Methods

The 2010-2021 PearlDiver M157 database was queried for adult THA cases. Those with nerve injury within 90 days of THA were identified. Patient age, sex, body mass index (BMI), Elixhauser comorbidity index (ECI), fracture indication, and surgery type (index vs revision) were assessed for correlation with nerve injury by multivariate analyses.

Results

Out of 750,695 THAs, 2659 (0.35%) had nerve injuries. Multivariate analysis revealed independent predictors of nerve injury in decreasing odds ratio (OR) order to include: revision procedure (OR: 2.13), female sex (OR 1.35), ECI (ECI 1-2 [OR 1.27], ECI 3-4 [OR 1.43], and ECI ≥5 [OR 1.59]) and age (OR 1.02 per decade decrease) (P < .05 for each). Pertinent negatives by multivariate analysis included underweight BMI (<20), and fracture indication. Individuals with morbidly obese BMI status (≥35) had a decreased risk of nerve injury (OR 0.84, P = .019).

Conclusions

THA-related nerve injury was found to be low at 0.35%. Factors independently associated with this adverse outcome were defined, of which the greatest risk was seen in revision procedures. These risk factors, derived from the largest cohort to date, may be helpful for risk stratification and patient counseling.

VDR Gene Polymorphisms (BsmI, FokI, TaqI, ApaI) in Total Hip Arthroplasty Outcome Patients

A total hip arthroplasty (THA) can improve quality of life, but loosening of the hip prosthesis is a complex problem in which vitamin D may also play a role. The Vitamin D Receptor (VDR) is involved in the response of cells to the action of vitamin D, and its genetic variability raises the question of whether individual differences could influence the risk of prosthesis loosening. The aim of this study was to investigate the relationship between VDR single nucleotide polymorphisms (SNPs) (ApaI, BsmI, FokI and TaqI) and the serum VDR and 25(OH)D levels in three groups of patients: (1) arthroscopy patients after THA without loosening of the prosthesis (CA-Control Arthroplasty), (2) patients after THA with loosened hip prostheses (L-Loosening) and (3) the control group (C-Control). Our results suggest that the genotypes tt of TaqI, BB of BsmI, and FF of FokI may influence the VDR effect in patients with loosened protheses. Our results showed that the ACAC haplotype (AtBF) was over two times more frequent in the L group than in CA + C: OR =2.35 [95% CI 1.44-3.83; p = 0.001]. There was no significant correlation between the VDR and serum 25(OH)D levels, but there were differences between studied groups.

Long-Term Outcomes and a Radiological Assessment of Hydroxyapatite-Tricalcium Phosphate-Coated Total Hip Arthroplasty (Trilogy/Zimmer): A Long-Term Follow-Up Study

Background and Objectives: Favorable short- and mid-term results for hydroxyapatite (HA)-tricalcium phosphate (TCP)-coated total hip arthroplasty (THA) (Trilogy/Zimmer) have been reported in the literature; however, the long-term results beyond 15 years have not been documented. Therefore, this study evaluated the long-term postoperative results, radiological bone changes, and implant fixation of the acetabular component of HA-TCP-coated THA. Materials and Methods: This is a retrospective cohort study of 212 patients who underwent primary HA-TCP-coated THA (Trilogy/Zimmer) at our institution between 1 October 2002, and 31 March 2008; 166 who were available for follow-up at least 15 years postoperatively were included (capture rate: 78.3%). All implants were Trilogy/Zimmer. We investigated the survival rate, with aseptic loosening as the endpoint. Clinical evaluations included the presence of dislocation and a modified Harris Hip Score (mHHS) preoperatively and at the final observation. Results: The mean age at surgery and at the follow-up period were 57.7 ± 9.6 and 17.1 ± 1.5 years, respectively. The survival rate was 99.4% (165/166), with aseptic loosening as the endpoint. Dislocation was observed in 4/166 (2.4%) patients. The mHHS improved significantly from 46.1 points preoperatively to 82.2 points during the last survey (p < 0.05). The results revealed that fixation was favorable in all cases except for one case of aseptic loosening. The Trilogy implant coated with HA-TCP was highly effective in bone induction, and bone ingrowth was considered to have occurred without failure, further indicating its usefulness. The long-term results of cementless THA using an HA-TCP coating (Trilogy/Zimmer), with a mean follow-up period of 17.1 years, revealed a commendable survival rate of 99.4%, considering aseptic loosening as the endpoint. Conclusions: HA-TCP-coated THA (Trilogy/Zimmer) had good long-term results. However, further long-term observation is required in patients who have undergone this surgery, and the stem side should be evaluated and investigated, including comorbidities.

Outcomes of Total Hip Arthroplasty in Patients Who Have Ehlers-Danlos Syndrome: A Matched Cohort Study

BACKGROUND

Total hip arthroplasty (THA) is an effective surgical treatment for severe osteoarthritis of the hip. While THA is considered a reliable and safe procedure, outcome data on patients who have Ehlers-Danlos syndrome (EDS) is limited. The purpose of this study was to compare rates of postoperative complications after primary THA in patients who have EDS against matched controls.

METHODS

A large national database was searched to identify patients who underwent THA between 2009 and 2020. Patients younger than 18 years, those who have a history of prior THA, and those undergoing THA for a hip fracture were excluded from analysis. Propensity score matching was utilized to match patients who had EDS with patients who did not have EDS at a 1:4 ratio. Rates of medical and surgical complications at 90 days and 2 years were queried and compared between the cohorts using multivariable logistic regression. We identified 118 patients who had EDS and underwent primary THA, who were then matched with 418 controls.

RESULTS

At 90 days, the EDS cohort had greater rates of dislocation (8.5 versus 3.8%, P = 0.038). At 2 years, the EDS cohort had greater odds of dislocation (OR [odds ratio] 2.47, P = 0.018), aseptic loosening (OR 6.91, P = 0.002), and aseptic revision (OR 2.66, P = 0.02).

CONCLUSIONS

Patients who have EDS possess significantly higher odds of complications after THA compared to matched controls, including dislocation, aseptic loosening, and aseptic revision. Careful surgical planning in these patients should be made to prevent dislocation and potentially minimize the risk of other prosthesis-related complications leading to revision.

Risk factors for complications in total hip arthroplasty

INTRODUCTION AND OBJECTIVE

Hip arthroplasty represents a significant advancement in the treatment of refractory chronic joint pain, improving quality of life and functionality. The objective of this study is to identify the risk factors associated with local and systemic complications in patients treated with total hip arthroplasty.

METHODS

Observational, analytical, retrospective cohort study, which included 304 participants treated with total hip replacement. Comparison of variables between two groups was performed; 38 participants in the group with complications and 266 participants in the group without complications.

RESULTS

The mean age in the complication group was 66 years (SD 18.7) and in the uncomplicated group it was 67,1 years (SD 15.1) (p 0,686). Female sex was observed in 73.3% of the group with complications and 65% in the group without complications. (p 0.292). Risk factors were: hip fracture as an indication for arthroplasty RR 1.33 [95% CI 1.004;1.775 p 0.047], coronary heart disease RR 1.31 [95% CI 1.067;1.616 p 0.010] and surgical bleeding equal to or greater than 400 cc RR 1.11 [95% CI 1.012;1.218 p 0.028].

CONCLUSIONS

The risk factors for complications in total hip arthroplasty were: hip fracture as the indication for arthroplasty, coronary artery disease, and surgical bleeding equal to or greater than 400 cc.

Total Joint Arthroplasty Is a Viable Treatment Option for Patients With Osteonecrosis and Osteoarthritis After Bone Marrow Transplantation

Background

Long-term survival in patients who receive bone marrow transplantation (BMT) is increasing. However, osteonecrosis and secondary osteoarthritis (OA) of the hip and knee are common complications in this population due to post-transplant steroid treatment to prevent graft vs host disease. The purpose of this study was to evaluate the outcomes of total joint arthroplasty (TJA) in patients with prior BMT and compare them to those of patients undergoing TJA for primary OA.

Methods

Patients with a history of BMT undergoing primary TJA from 2013 to 2021 were retrospectively reviewed. Patients were matched 1:1 by surgical site, sex, age, body mass index, American Society of Anesthesiologists score, and Elixhauser Comorbidity Index to patients undergoing TJA for primary OA. Demographics, intraoperative blood loss, perioperative transfusion requirements, hospital length of stay, 90-day emergency department visits and readmissions, all-cause revisions, and 2-year mortality were compared between cohorts.

Results

There were 17 patients undergoing total knee arthroplasty (TKA) after BMT (TKA-BMT) and 43 patients undergoing total hip arthroplasty (THA) after BMT (THA-BMT). More TKA-BMT and THA-BMT patients were immunosuppressed preoperatively compared to 17 matched TKA-OA and 43 THA-OA patients (P = .018 and P < .001). There were no other significant perioperative differences between BMT and OA groups. Two-year patient and implant survivorship for TKA-BMT and THA-BMT patients were high and not statistically different from TKA-OA and THA-OA cohorts.

Conclusions

TJA after BMT provides satisfactory perioperative and short-term outcomes and is a viable treatment option for patients with osteonecrosis and secondary OA after BMT treatment.

Differences in Reimbursements, Procedural Volumes, and Patient Characteristics Based on Surgeon Gender in Total Hip Arthroplasty

BACKGROUND

Prior studies have suggested there may be differences in reimbursement and practice patterns by gender. The purpose of this study was to comprehensively evaluate differences in reimbursement, procedural volume, and patient characteristics in total hip arthroplasty (THA) between men and women surgeons from 2013 to 2021.

METHODS

The Medicare Physician and Other Practitioners database from 2013 to 2021 was queried. Inflation-adjusted reimbursement, procedural volume, surgeon information, and patient demographics were extracted for surgeons performing over 10 primary THAs each year. Wilcoxon, t-tests, and multivariate linear regressions were utilized to compare men and women surgeons.

RESULTS

Only 1.4% of THAs billed to Medicare between 2013 and 2021 were billed by women surgeons. Men surgeons earned significantly greater reimbursement nationally in 2021 compared to women surgeons per THA ($1018.56 versus $954.17, P = 0.03), but no difference was found when assessing each region separately. Reimbursement declined at similar rates for both men and women surgeons (-18.3 versus -19.8%, P = 0.38). An increase in the proportion of women surgeons performing THA between 2013 and 2021 was seen in all regions except the South. In 2021, the proportion of all THAs performed by women surgeons was highest in the West (3.5%) and lowest in the South (1.0%). Women surgeons had comparable patient populations in terms of age, race, comorbidity status, and Medicaid eligibility to their men counterparts, but performed significantly fewer services per beneficiary (5.6 versus 8.1, P < 0.001) and fewer unique services (51.1 versus 69.6, P < 0.001).

CONCLUSIONS

Average reimbursement per THA has declined at a similar rate for men and women physicians between 2013 and 2021. Women's representation in THA surgery nationwide has nearly doubled between 2013 and 2021, with the greatest increase in the West. However, there are notable differences in billing practices between genders.

Incidence and Predictors of Subsidence Using Modular, Tapered, Fluted Titanium Femoral Stems in Aseptic Revision Total Hip Arthroplasty

BACKGROUND

Tapered, fluted titanium (TFT) femoral stems have become the gold standard in revision total hip arthroplasty (rTHA). However, there is a paucity of data on TFT stem subsidence rates following aseptic rTHA. Subsidence can lead to instability, mechanical failure, leg-length discrepancy, and may require revision surgery. This study evaluated the incidences and predictors of TFT subsidence in aseptic rTHA.

METHODS

A total of 102 TFT femoral stems of 4 designs were retrospectively reviewed. Stem subsidence was measured on digital radiographs taken immediately after surgery and at standard clinical follow-up. Patient characteristics, risk factors for subsidence, revision etiologies, and implant characteristics were recorded. Patient-reported outcome measures were also evaluated for a subset of cases.

RESULTS

Overall, 12% of stems subsided >1 cm, and subsidence was minimal (<3 mm) in ≥64% of cases. From immediate postoperative to 1-month radiographic follow-up, 79% of stems subsided a mean of 2.9 mm (range, 0.1 to 12 mm). Beyond 1 month, subsidence was minimal for ≥77% of cases. In multivariate analyses, women and less femoral implant canal fill were associated with greater subsidence (P ≤ .034). The TFT stem design was not associated with early subsidence (P = .816). There were no modular junction fractures. There were 2 fractures and 2 subsidence-related revisions for aseptic loosening that occurred postoperatively.

CONCLUSIONS

The amount of subsidence in TFT stems was low and was detectable in the early (less than 1 year) postoperative period. Maximizing TFT stem fill within the femoral canal appears to reduce the risk of subsidence without increasing femoral fracture rates and should be the goal with implantation of these devices.

LEVEL OF EVIDENCE

IV-Case Series, No Control Group.

A Novel Digital Templating Method for Total Hip Arthroplasty in Patients With Unilateral Hip Arthrosis

BACKGROUND

Identification of the hip center of rotation (HCOR) before total hip arthroplasty (THA) is crucial for achieving optimal implant position and size, and for restoring native biomechanics around the hip joint. Current techniques for determining the HCOR in cases of abnormal hip anatomy are limited and unreliable. This study presents a novel technique using open-access software for preoperative THA templating for patients with significantly abnormal hip anatomy due to unilateral hip arthrosis. The aim is to reliably predict the HCOR and acetabular implant size compared with a traditional intraoperative method.

MATERIALS AND METHODS

This retrospective study involved 20 patients with unilateral hip arthrosis who underwent THA. Preoperative templating was performed using the experimental technique, and the position of the HCOR was measured on preoperative and postoperative radiographs. The positions of the predicted and actual HCOR were compared, along with the inclination and size of the acetabular component.

RESULTS

The difference between the predicted and actual HCOR positions was insignificant (0.43±0.22 mm vertically and 0.18±0.20 mm horizontally), and there was a positive correlation between them (r=0.78, P<.005; r=0.72, P<.005). The agreement between the predicted and actual acetabular implant sizes was 85%, with near-perfect interobserver agreement (Cohen's kappa=0.827).

CONCLUSION

This novel technique provides a reliable method for predicting HCOR and acetabular implant size for THA in cases of unilateral hip arthrosis. This technique may help optimize biomechanics and improve outcomes in challenging cases. Further research and validation are warranted to establish its broader applicability. [Orthopedics. 2024;47(3):e139-e145.].

Oral as compared to intravenous tranexamic acid to limit peri-operative blood loss associated with primary total hip arthroplasty: A randomised noninferiority trial

BACKGROUND

Oral as compared to intravenous tranexamic acid (TXA) is an attractive option, in terms of cost and safety, to reduce blood loss and transfusion in total hip arthroplasty. Exclusion criteria applied in the most recent randomised trials may have limited the generalisability of oral tranexamic acid in this indication. Larger and more inclusive studies are needed to definitively establish oral administration as a credible alternative to intravenous administration.

OBJECTIVES

To assess the noninferiority of oral to intravenous TXA at reducing intra-operative and postoperative total blood loss (TBL) in primary posterolateral approached total hip arthroplasty (PLTHA).

DESIGN

Noninferiority, single centre, randomised, double-blind controlled study.

SETTING

Patients scheduled for primary PLTHA. Data acquisition occurred between May 2021 and November 2022 at the University Hospital of Liège, Belgium.

PATIENTS

Two hundred and twenty-eight patients, randomised in a 1 : 1 ratio from a computer-generated list, completed the trial.

INTERVENTIONS

Administration of 2 g of oral TXA 2 h before total hip arthroplasty and 4 h after incision (Group oral) was compared to the intravenous administration of 1 g of TXA 30 min before surgery and 4 h after incision (Group i.v.).

MAIN OUTCOME MEASURES

TBL (measured intra-operative and drainage blood loss up to 48 h after surgery, primary outcome), decrease in haemoglobin concentration, D-Dimer at day 1 and day 3, transfusion rate (secondary outcomes).

RESULTS

Analyses were performed on 108 out of 114 participants (Group i.v.) and 104 out of 114 participants (Group oral). Group oral was noninferior to Group i.v. with regard to TBL, with a difference between medians (95% CI) of 35 ml (-103.77 to 33.77) within the noninferiority margins. Median [IQR] of estimated TBL was 480 ml [350 to 565] and 445 ml [323 to 558], respectively. No significant interaction between group and time was observed regarding the evolution of TBL and haemoglobin over time.

CONCLUSIONS

TXA as an oral premedication before PLTHA is noninferior to its intravenous administration regarding peri-operative TBL.

TRIAL REGISTRATION

European Clinical Trial Register under EudraCT-number 2020-004167-29 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-004167-29/BE ).

Short stem hip arthroplasty with the optimys prosthesis is a safe and effective option for obese patients: a mid-term follow-up multicenter study

INTRODUCTION

Short stems are a valuable option in young patients undergoing total hip arthroplasty (THA) because of their bone stock preserving properties facilitating revision hip arthroplasty. Although the effect of obesity on conventional THA is well studied, data about short stem THA in obese patients are lacking. Therefore, this study aimed to investigate the influence of obesity on complications, revisions, and outcome after short stem THA.

MATERIALS AND METHODS

This multicenter, observational cohort study included patients undergoing short stem THA with the optimys prosthesis. Follow-up examinations were performed at specific intervals up to 7 years postoperatively. Operation characteristics, general and specific complications, revisions, VAS rest pain, VAS load pain, VAS patient satisfaction, and Harris Hip Score (HHS) were recorded and statistically compared between obese (BMI ≥ 30 kg/m2) and non-obese (BMI < 30 kg/m2) patients.

RESULTS

Of the 224 patients included with a mean follow-up of 87.2 months (range 81.9-104.0), 69 were assigned to the OB group and 155 to the non-OB group. A minimally invasive approach was significantly less often selected in obese patients (p = 0.049), whereas operating time and length of hospital stay were not significantly different. The rate of general and specific complications did not significantly differ between both groups. Survival of the optimys prosthesis was 99.1% at 7-year follow-up and one patient per group had to undergo revision surgery. VAS rest pain, load pain, and satisfaction improved from preoperatively to postoperatively in both groups without a significant difference between both groups. While the HHS was improved from preoperatively to postoperatively, obese patients showed a significantly lower HHS at the 7-year follow-up (p = 0.01) but still exhibited an excellent scoring above the PASS threshold.

CONCLUSION

Short stem THA with the optimys prosthesis is a safe and effective option also in obese patients with an excellent clinical outcome and a low complication rate.

Impact of Demographic Variables on Recovery After Total Hip Arthroplasty

BACKGROUND

Several patient factors affect recovery after total hip arthroplasty (THA). However, the impact of these variables on patient-reported outcome measure recovery curves following THA has not been defined. Our goal was to quantify the influence of multiple variables on recovery after primary THA.

METHODS

There were 1,724 patients in a multicenter study included. Variables included sex, race/ethnicity, anxiety/depression, body mass index, tobacco, and preoperative opioid use. The Hip disability and Osteoarthritis Score for Joint Replacement (HOOS JR) was recorded at multiple time points. Recovery curves were created using longitudinal estimating equations.

RESULTS

Patients who were women, obese, or smokers demonstrated lower HOOS JR scores at all time points. Preoperative opioid use was also correlated with lower HOOS JR scores, but this difference diminished after 6 months. Black patients demonstrated lower HOOS JR scores compared to Caucasians, and this relative difference increased out to 1-year postoperatively (P = .018). Hispanics also had lower HOOS JR scores, but scores recovered at similar rates compared to non-Hispanics. Patients who had only anxiety or depression had similar HOOS JR scores compared to patients who did not have anxiety or depression. However, patients who had both anxiety and depression had lower HOOS JR scores compared to patients who had neither (P = .049), and this relative difference became greater at 1-year postoperatively (P = .002).

CONCLUSIONS

Several factors including race/ethnicity, opioid use, and mental health influence recovery trajectory following THA. This information helps provide more individualized counseling about expectations after THA and focus targeted interventions to improve outcomes in at-risk groups.

A modified frailty index predicts complication, readmission, and 30-day mortality following the revision total hip arthroplasty

INTRODUCTION

This study aimed to develop a modified frailty index (MFI) to predict the risks of revision total hip arthroplasty (THA).

METHODS

Data from the American College of Surgeons - National Surgical Quality Improvement Program were analyzed for patients who underwent revision THA from 2015 to 2020. An MFI was composed of the risk factors, including severe obesity (body mass index > 35), osteoporosis, non-independent function status prior to surgery, congestive heart failure within 30 days of surgery, hypoalbuminemia (serum albumin < 3.5), hypertension requiring medication, type 1 or type 2 diabetes, and a history of chronic obstructive pulmonary disease or pneumonia. The patients were assigned based on the MFI scores (MFI0, no risk factor; MFI1, 1-2 risk factors; MFI2, 3-4 risk factors; and MFI3, 5+ risk factors). Confidence intervals were set at 95% with a P value less than or equal to 0.05 considered statistically significant.

RESULTS

A total of 17,868 patients (45% male, 55% female) were included and had an average age of 68.5 ± 11.5 years. Odds of any complication, when compared to MFI0, were 1.4 (95% CI [1.3, 1.6]) times greater for MFI1, 3.2 (95% CI [2.8, 3.6]) times greater for MFI2, and 10.8 (95% CI [5.8, 20.0]) times greater for MFI3 (P < 0.001). Odds of readmission, when compared to MFI0, were 1.4 (95% CI [1.3, 1.7]) times greater for MFI1, 2.5 (95% CI [2.1, 3.0]) times greater for MFI2, and 4.1 (95% CI [2.2, 7.8]) times greater for MFI3 (P < 0.001).

CONCLUSION

Increasing MFI scores correlate with increased odds of complication and readmission in patients who have undergone revision THA. This MFI may be used to predict the risks after revision THA.

Total hip arthroplasty in patients with colostomy: impact on inpatient complications, hospital costs, and length of stay

INTRODUCTION

The presence of permanent end-colostomy is traditionally thought of as a risk factor for complications following orthopedic joint replacement; however, literature supporting this association is scarce. This study aims to discern how length of stay, cost of stay, and inpatient complications following total hip arthroplasty (THA) are impacted by presence of colostomy.

METHODS

Data from the National Inpatient Sample was analyzed by International Classification of Diseases, 10th Revision, Clinical Modification regarding THA in patients with and without end-colostomy. Unmatched and matched analyses comparing length of stay, cost of stay, and post-operative adverse outcomes between the two groups were conducted. In the unmatched analysis, 445 THA patients with colostomy were compared to 367,449 THA patients without colostomy. The colostomy patients were then matched for age, sex, race, diabetes, obesity, and the matched groups consisted of 445 patients with and 425 patients without colostomy, respectively.

RESULTS

Compared to the THA without colostomy group, the colostomy group was significantly older, had longer hospital stays, and greater cost of stay. When matched for age and comorbidities, length of hospital stay (p < 0.001) and cost of stay (p = 0.002) remained significantly higher. The colostomy group was at significantly increased risk for periprosthetic fracture, dislocation, and infection compared to all THA patients. When matched for age and common comorbidities, the colostomy group had significantly higher risk in only periprosthetic dislocation [p = 0.003, OR 11.8 (1.6-4.6, 95% CI)] and periprosthetic infection [p < 0.05, OR 2.7 (0.97-7.7 95% CI)].

CONCLUSION

Patients with colostomy are at risk of longer hospital courses and greater incurred costs following THA compared to patients without colostomy. They are additionally at significantly increased risk of periprosthetic dislocation and periprosthetic infection, warranting treatment as high-risk patients.

STUDY DESIGN

Retrospective cohort study.

Genetic Risk Factors for End-Stage Hip Osteoarthritis Treated With Total Hip Arthroplasty: A Genome-wide Association Study

BACKGROUND

Although a genetic component to hip osteoarthritis (OA) has been described, focused evaluation of the genetic components of end-stage disease is limited. We present a genomewide association study for patients undergoing total hip arthroplasty (THA) to characterize the genetic risk factors associated with end-stage hip osteoarthritis (ESHO), defined as utilization of the procedure.

METHODS

Patients who underwent primary THA for hip OA were identified in a national patient data repository using administrative codes. Fifteen thousand three hundred and fifty-five patients with ESHO and 374,193 control patients were identified. Whole genome regression of genotypic data for patients who underwent primary THA for hip OA corrected for age, sex, and body mass index (BMI) was performed. Multivariate logistic regression models were used to evaluate the composite genetic risk from the identified genetic variants.

RESULTS

There were 13 significant genes identified. Composite genetic factors resulted in an odds ratio 1.04 for ESHO (P < .001). The effect of genetics was lower than that of age (Odds Ratio (OR): 2.38; P < .001) and BMI (1.81; P < .001).

CONCLUSION

Multiple genetic variants, including 5 novel loci, were associated with end-stage hip OA treated with primary THA. Age and BMI were associated with greater odds of developing end-stage disease when compared to genetic factors.

A multi-branch network to detect post-operative complications following hip arthroplasty on X-ray images

Background: Postoperative complications following total hip arthroplasty (THA) often require revision surgery. X-rays are usually used to detect such complications, but manually identifying the location of the problem and making an accurate assessment can be subjective and time-consuming. Therefore, in this study, we propose a multi-branch network to automatically detect postoperative complications on X-ray images. Methods: We developed a multi-branch network using ResNet as the backbone and two additional branches with a global feature stream and a channel feature stream for extracting features of interest. Additionally, inspired by our domain knowledge, we designed a multi-coefficient class-specific residual attention block to learn the correlations between different complications to improve the performance of the system. Results: Our proposed method achieved state-of-the-art (SOTA) performance in detecting multiple complications, with mean average precision (mAP) and F1 scores of 0.346 and 0.429, respectively. The network also showed excellent performance at identifying aseptic loosening, with recall and precision rates of 0.929 and 0.897, respectively. Ablation experiments were conducted on detecting multiple complications and single complications, as well as internal and external datasets, demonstrating the effectiveness of our proposed modules. Conclusion: Our deep learning method provides an accurate end-to-end solution for detecting postoperative complications following THA.

Trabecular titanium cups in hip revision surgery: a systematic review of the literature

Background

Hip revision surgery in extensive acetabular bone defects represents a complex challenge for hip surgeons. The primary goal is to obtain a stable acetabular component and restore the hip biomechanics. Through the years, different prosthetic implants have been developed to perform acetabular revision depending on bone loss location and extension. This systematic review aims to summarize the clinical outcomes and complications reported with trabecular titanium (TT) cups in hip revision surgery.

Methods

A literature search of four databases (PubMed, Embase, Scopus and the Cochrane Database of systematic reviews) was performed according to the PRISMA guideline from January 2008 to December 2022. All studies written in English and reporting the clinical outcome of patients undergoing revision total hip arthroplasty using Delta TT cups were included. The initial screening identified 378 studies. Each eligible clinical article was analyzed according to the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence (LoE), and the papers' methodological quality was evaluated using The Methodological Index for Non-Randomized Studies Criteria (MINORS) score.

Results

Eight clinical studies were included in the analysis. A total of 523 hip revisions were analyzed. Delta TT cups were used in 3.9%, Delta TT one cups in 46.8%, and Delta TT revisions in 49.3%. Paprosky IIIa was the most frequent acetabular bone defect reported in 26.4% of cases. The overall survival rate of TT cups was 93.4%. The dislocation was the most frequent complication in 4.1% of patients, while the prevalence of aseptic loosening was 1.5.

Conclusions

Managing severe acetabular bone defects remains a complex challenge for hip surgeons. Since their introduction, TT cups have exhibited good clinical results, with complication rates in line with or lower than those reported by similar implants.

Bone Cement Implantation Syndrome: A Rare Disaster Following Cemented Hip Arthroplasties-Clinical Considerations Supported by Case Studies

Severe symptoms such as hypoxemia, hypotension, and unexpected loss of consciousness may develop during surgical interventions that use polymethyl methacrylate (PMMA), or as it is commonly known, bone cement. Physicians recognize this amalgam of clinical manifestations more and more as a distinct entity that bears the name of bone cement implantation syndrome (BCIS). Trauma cases, especially hip fractures, are seen to have a higher incidence of developing this complication compared to orthopedic elective ones. This research aims to present a detailed description of six severe BCIS cases in order to raise awareness and to emphasize its importance. Five of them had fatal outcomes, which demonstrate the necessity of future research on this topic, as little is known about it presently. In the Discussion section, a narrative overview from the scientific literature is performed on potential risk factors, prevention measures, and management strategies. The experience gathered through this case series may aid medical staff in the development of diagnostic and therapeutic protocols, thus improving safety when cemented surgical techniques are used on a high-risk group of patients.

Development and validation of a novel nomogram to predict the risk of the prolonged postoperative length of stay for lumbar spinal stenosis patients

BACKGROUND

Lumber spinal stenosis (LSS) is the increasingly reason for spine surgery for elder patients since China is facing the fastest-growing aging population. The aim of this research was to create a model to predict the probabilities of requiring a prolonged postoperative length of stay (PLOS) for lumbar spinal stenosis patients, minimizing the healthcare burden.

METHODS

A total of 540 LSS patients were enrolled in this project. The outcome was a prolonged PLOS after spine surgery, defined as hospitalizations ≥ 75th percentile for PLOS, including the day of discharge. The least absolute shrinkage and selection operator (LASSO) was used to identify independent risk variables related to prolonged PLOS. Multivariable logistic regression analysis was utilized to generate a prediction model utilizing the variables employed in the LASSO approach. The receiver operating characteristic (ROC) curve's area under the curve (AUC) and the calibration curve's respective curves were used to further validate the model's calibration with predictability and discriminative capabilities. By using decision curve analysis, the resulting model's clinical effectiveness was assessed.

RESULTS

Among 540 individuals, 344 had PLOS that was within the usual range of P75 (8 days), according to the interquartile range of PLOS, and 196 had PLOS that was above the normal range of P75 (prolonged PLOS). Four variables were incorporated into the predictive model, named: transfusion, operation duration, blood loss and involved spine segments. A great difference in clinical scores can be found between the two groups (P < 0.001). In the development set, the model's AUC for predicting prolonged PLOS was 0.812 (95% CI: 0.768-0.859), while in the validation set, it was 0.830 (95% CI: 0.753-0.881). The calibration plots for the probability showed coherence between the expected probability and the actual probability both in the development set and validation set respectively. When intervention was chosen at the potential threshold of 2%, analysis of the decision curve revealed that the model was more clinically effective.

CONCLUSIONS

The individualized prediction nomogram incorporating five common clinical features for LSS patients undergoing surgery can be suitably used to smooth early identification and improve screening of patients at higher risk of prolonged PLOS and minimize health care.

Epidemiological Characteristics and Trends of Primary Hip Arthroplasty in Five Tertiary Hospitals: A Multicenter Retrospective Study

OBJECTIVE

The number of primary hip arthroplasty (PHA) has increased sharply in recent years. Whether the epidemiological characteristics and trends of PHA have changed are unknown. This study aims to analyze the epidemiological characteristics and trends of those patients are urgent for public health institutions.

METHODS

The data of patients who underwent PHA in five tertiary hospitals from January 2011 to December 2020 were retrospectively reviewed. A total of 21,898 patients were included, most of whom were aged 60-69 years (25.1% males and 31.5% females). According to the hospitalization date, the patients were divided into two groups (Group A and Group B). The patients admitted between January 2011 and December 2015 were designated as Group A (7862), and those admitted between January 2016 and December 2020 were designated as Group B (14036). The patient data of the two groups, including sex, age, disease causes, body mass index (BMI), comorbidities, surgical procedures, hospital stay duration, and hospitalization costs, were analyzed by Pearson chi-Square test, Student t test or Mann-Whitney U test.

RESULTS

More women were included in Group B than in Group A (58.5% vs 52.5%, P < 0.001). The mean age of Group B was less than that of Group A (62.27 ± 14.77 vs 60.69 ± 14.44 years, P < 0.001). Femoral head necrosis was the primary pathogenic factor in both groups, with a higher proportion in Group B than in Group A (55.5% vs 45.5%, P < 0.001). Significant differences were found between the two groups in BMI, comorbidities, surgical procedures, hospital stay duration, and hospitalization costs. Total hip arthroplasty (THA) was the most common surgical procedure in both groups, with a higher proportion in Group B than in Group A (89.8% vs 79.3%, P < 0.001). The proportion of patients with one or more comorbidities was significantly higher in Group B than in Group A (69.2% vs 59.9%, P < 0.001). In addition, Group B had a shorter hospital stay duration and higher hospitalization costs than Group A.

CONCLUSION

Femoral head necrosis was the primary etiology for PHA in this study, followed by femoral neck fracture and hip osteoarthritis. Patients who underwent PHA exhibited a higher percentage of femoral head necrosis; underwent THA more often; and had larger BMIs, more comorbidities, higher medical costs, and younger age in the past decade.

Updates on Biomaterials Used in Total Hip Arthroplasty (THA)

One of the most popular and effective orthopedic surgical interventions for treating a variety of hip diseases is total hip arthroplasty. Despite being a radical procedure that involves replacing bone and cartilaginous surfaces with biomaterials, it produces excellent outcomes that significantly increase the patient's quality of life. Patient factors and surgical technique, as well as biomaterials, play a role in prosthetic survival, with aseptic loosening (one of the most common causes of total hip arthroplasty failure) being linked to the quality of biomaterials utilized. Over the years, various biomaterials have been developed to limit the amount of wear particles generated over time by friction between the prosthetic head (metal alloys or ceramic) and the insert fixed in the acetabular component (polyethylene or ceramic). An ideal biomaterial must be biocompatible, have a low coefficient of friction, be corrosion resistant, and have great mechanical power. Comprehensive knowledge regarding what causes hip arthroplasty failure, as well as improvements in biomaterial quality and surgical technique, will influence the survivability of the prosthetic implant. The purpose of this article was to assess the benefits and drawbacks of various biomaterial and friction couples used in total hip arthroplasties by reviewing the scientific literature published over the last 10 years.

Is the construct stability of the acetabular cup affected by the acetabular screw configuration in bone defect models?

BACKGROUND

In revision surgery with significant segmental acetabular defects, adequate implant selection and fixation methods are critical in determining successful bony ingrowth. Commercially available total hip prosthesis manufacturers generally offer additional multi-hole options of acetabular shells with identical designs for use in revision THAs where screw holes configurations vary from product to product. This study aims to compare the mechanical stability of the two types of acetabular screw constructs for the fixation of acetabular components: spread-out and pelvic brim-focused configurations.

METHODS

We prepared 40 synthetic bone models of the male pelvis. In half of the samples with acetabular defects, identical curvilinear bone defects were manually created using an oscillating electrical saw. On the right side, multi-hole-cups in which the direction of the screw holes are centered on the pelvic brim (brim-focused) and, on the left side, multi-hole-cups with the direction of the screw hole spread throughout the acetabulum (spread-out) were implanted into the pelvic synthetic bones. Coronal lever-out and axial torsion tests were performed with a testing machine, measuring load versus displacement.

RESULTS

The average torsional strengths were significantly higher in the spread-out group over the brim-focused group regardless of the presence of the segmental defect of the acetabulum (p < 0.001). But for the lever-out strength, the spread-out group exhibited significantly higher average strength over the brim-focused group for the intact acetabulum (p = 0.004), whereas the results were reversed in the brim-focused group when the defects were generated (p < 0.001). The presence of acetabular defects reduced the average torsional strengths of the two groups by 68.66% versus 70.86%. In comparison, the decrease in the average lever-out strength was less significant for the brim-focused group than the spread-out group (19.87% vs. 34.25%) (p < 0.001).

CONCLUSION

Constructs of multi-hole acetabular cups with the spread-out screw holes configuration exhibited statistically better axial torsional strength and coronal lever-out strength. With the presence of posterior segmental bone defects, the spread-out constructs demonstrated significantly better tolerance to axial torsional strength. Still, they exhibited inverted results of higher lever-out strength in the pelvic brim-focused constructs.

The Challenge of Periprosthetic Joint Infection Diagnosis: From Current Methods to Emerging Biomarkers

Due to the increase in the life span and mobility at older ages, the number of implanted prosthetic joints is constantly increasing. However, the number of periprosthetic joint infections (PJIs), one of the most severe complications after total joint arthroplasty, also shows an increasing trend. PJI has an incidence of 1-2% in the case of primary arthroplasties and up to 4% in the case of revision operations. The development of efficient protocols for managing periprosthetic infections can lead to the establishment of preventive measures and effective diagnostic methods based on the results obtained after the laboratory tests. In this review, we will briefly present the current methods used in PJI diagnosis and the current and emerging synovial biomarkers used for the prognosis, prophylaxis, and early diagnosis of periprosthetic infections. We will discuss treatment failure that may result from patient factors, microbiological factors, or factors related to errors during diagnosis.