Cemented Versus Cementless Femoral Fixation for Total Hip Arthroplasty Following Femoral Neck Fracture in Patients Aged 65 and Older.

BACKGROUND: Femoral neck fractures are common in individuals over 65, necessitating quick mobilization for the best outcomes. There's ongoing debate about the optimal femoral component fixation method in total hip arthroplasty (THA) for these fractures. Recent U.S. data shows a preference for cementless techniques in over 93% of primary THAs. Nonetheless, cemented fixation might offer advantages like fewer revisions, reduced periprosthetic fractures, lesser thigh pain, and enhanced long-term implant survival for those above 65. This study compares cementless and cemented fixation methods in THA, focusing on postoperative complications in patients aged 65 and older. METHODS: We analyzed a national database to identify patients aged 65+ who underwent primary THA for femoral neck fractures between 2016 and 2021, using either cementless (n = 2,842) or cemented (n = 1,124) techniques. A 1:1 propensity-matched analysis was conducted to balance variables such as age, sex, and comorbidities, resulting in two equally sized groups (n = 1,124 each). We evaluated outcomes like infection, venous thromboembolism (VTE), wound issues, dislocation, periprosthetic fracture, etc., at 90 days, 1 year, and 2 years post-surgery. A P-value < 05 indicated statistical significance. RESULTS: The cemented group initially consisted of older individuals, more females, and higher comorbidity rates. Both groups had similar infection and wound complication rates, and aseptic loosening. The cemented group, however, had lower periprosthetic fracture rates (2.5 versus 4.4%, P = .02) and higher VTE rates (2.9 versus 1.2%, P = .01) at 90 days. After 1 and 2 years, the cementless group experienced more aseptic revision surgeries. CONCLUSIONS: This study, using a large, national database and propensity-matched cohorts, indicates that cemented femoral component fixation in THA leads to fewer periprosthetic fractures and aseptic revisions, but a higher VTE risk. Fixation type choice should consider various factors, including age, sex, comorbidities, bone quality, and surgical expertise. This data can inform surgeons in their decision-making process.

Symptomatic Benign Prostatic Hyperplasia Is Not Associated With a Higher Risk of Periprosthetic Joint Infections and Periprosthetic Joint Infection-related Revisions After Primary THA.

BACKGROUND: Symptomatic benign prostatic hyperplasia (sBPH) is a potential risk factor for periprosthetic joint infection (PJI), a leading cause of implant failure and revision THA. However, the available evidence is mixed on whether this is the case. QUESTIONS/PURPOSES: (1) What is the prevalence of sBPH in male recipients of primary THA by age group? (2) Do patients with sBPH compared with those without sBPH have higher 30-day, 90-day, and 2-year odds of PJI and higher 30-day and 90-day odds of urinary catheterization, urinary tract infection (UTI), and sepsis after primary THA? (3) Do patients with sBPH compared with those without sBPH have lower survivorship free from PJI-related revision at 5 years after THA? METHODS: The PearlDiver database was used as it provided the largest sample of patients across all payer types to perform longitudinal research. Between January 2010 and April 2021, 1,056,119 patients who underwent primary THA were identified. After applying the inclusion criteria (that is, male sex, minimum age of 18, and diagnosis of hip osteoarthritis) and exclusion criteria (that is, history of asymptomatic BPH or any other joint arthroplasty), 16% (172,866) of patients remained. A further 6% (59,500) of patients were excluded as they did not meet the minimum study follow-up of 2 years, leaving 11% (113,366) for analysis. Of those, patients with sBPH were matched to those without in a 1:4 ratio by age and comorbidities, including alcohol abuse, anemia, cardiovascular disorders, chronic pulmonary disease, diabetes mellitus, depression, obesity, peripheral vascular disorders, renal failure, and rheumatoid arthritis. Age and comorbidities of the two groups postmatch were balanced. Logistic regression was performed to analyze the odds for 30-day, 90-day, and 2-year postoperative complications. Survivorship free from PJI-related revision at 5 years after THA was estimated using the Kaplan-Meier method and compared with the log-rank test. RESULTS: Among male recipients of primary THA ages 65 or older, 24% (11,319 of 47,426) had a medical history of sBPH. We found no difference in the odds of PJI at 30 days, 90 days, and 2 years after primary THA between the two groups. PJI occurred in 0.5% (62 of 11,819), 0.8% (97 of 11,819), and 1.3% (150 of 11,819) of patients with sBPH versus in 0.5% (227 of 47,103), 0.8% (360 of 47,103), and 1.2% (570 of 47,103) of those without sBPH within 30 days (OR 1.09 [95% CI 0.82 to 1.43]), 90 days (OR 1.07 [95% CI 0.85 to 1.34]), and 2 years (OR 1.05 [95% CI 0.87 to 1.25]) after THA, respectively. Patients with sBPH compared with those without had higher odds of 30-day and 90-day urinary catheterization (OR 5.00 [95% CI 3.64 to 6.88] and OR 5.36 [95% CI 4.04 to 7.13], respectively), 30-day and 90-day UTI (OR 2.18 [95% CI 1.88 to 2.54] and OR 2.55 [95% CI 2.26 to 2.87], respectively), and 30-day and 90-day sepsis (OR 1.55 [95% CI 1.11 to 2.13] and OR 1.43 [95% CI 1.10 to 1.83], respectively). We found no difference in survival free from PJI-related revision at 5 years after THA between patients with and without sBPH (98.3% [95% CI 98.1% to 98.6%] versus 98.1% [95% CI 98.1% to 98.2%]; p = 0.10). CONCLUSION: sBPH is common among THA recipients, and surgeons should be aware of the added risk of postoperative urinary complications and sepsis in this subset that could lead to additional postoperative care requirements. Surgeons may consider perioperative measures such as preoperative use of short-form questionnaires to assess urinary symptoms, urology clearance or referral, and closer follow-up to improve care of sBPH patients undergoing THA. As currently available tools for assessing sBPH are limited and lack sensitivity as well as specificity, future studies may develop validated tools that can be used to quickly assess risk in sBPH patients before surgery. LEVEL OF EVIDENCE: Level III, therapeutic study.

Heart Failure is Associated with Early Medical and Surgery-Related Complications Following Total Hip Arthroplasty: A Propensity-Scored Analysis.

INTRODUCTION: There is a paucity of literature that examines how heart failure (HF) impacts surgery-related complications following total hip arthroplasty (THA). We hypothesized that patients who had HF will be at increased risk of early medical- and surgery-related complications following THA. METHODS: Patients who had HF and underwent primary THA between 2010 and 2019 were identified using a large national insurance database. Ninety-day incidence of various medical complications, surgery-related complications, and hospital utilizations were evaluated for patients who did and did not have HF, as well as subgroup analyses were performed on patients who were prescribed mortality-benefitting medications for HF 1 year prior to THA. Propensity score matching resulted in 34,000 HF patients who underwent primary THA and 340,000 matching patients. RESULTS: The HF cohort was associated with a higher 90-day incidence of pulmonary embolism (PE), deep vein thrombosis (DVT), transfusion, pneumonia, cerebrovascular accident (CVA), myocardial infarction (MI), sepsis, acute post hemorrhagic anemia, acute renal failure (ARF), and urinary tract infection (UTI), as well as 1-year risk of revision THA, periprosthetic joint infection (PJI), aseptic loosening, and dislocation compared to controls. The HF cohort was associated with a higher 90-day incidence of emergency department visits, readmissions, lengths of stay (LOS), and 1-year costs of care. The medication cohort was at decreased risk of PE, DVT, CVA, return to ED, readmission and MI within 90 days of surgery, and 1-year risk of revision THA and aseptic loosening. DISCUSSION: These findings may help to better risk-stratify patients who have HF and are scheduled to undergo THA, as well as call for additional surveillance of these patients in the immediate and early postoperative period. This study also helps surgeons and internists understand how chronic medications used to treat HF can impact medical- and surgery-related outcomes following THA.

The Effect of Preoperative Bisphosphonate Use on Total Hip Arthroplasty Outcomes.

BACKGROUND: Patients undergoing total hip arthroplasty (THA) commonly have osteoporosis for which bisphosphonates (BPs) are Food and Drug Administration (FDA)-approved for treatment. Bisphosphonate use post-THA is associated with decreased periprosthetic bone loss or revisions, and increased longevity of implants. However, evidence is lacking for preoperative bisphosphonate use in THA recipients. This study investigated the association between bisphosphonate use pre-THA and outcomes. METHODS: A retrospective review of a national administrative claims database was conducted. Among THA recipients who had a prior diagnosis of hip osteoarthritis and osteoporosis/osteopenia, the treatment group (BP-exposed) consisted of patients who had a history of bisphosphonate use at least 1 year before THA; controls (BP-naive) comprised patients who did not have preoperative bisphosphonate use. The BP-exposed were matched to BP-naive in a 1:4 ratio by age, sex, and comorbidities. Logistic regressions were used to calculate the odds ratio for intraoperative and 1-year postoperative complications. RESULTS: The BP-exposed group had significantly higher rates of intraoperative and 1-year postoperative periprosthetic fractures (odds ratio (OR): 1.39, 95% confidence interval (CI): 1.23, 1.57) and revisions (OR: 1.14, 95% CI: 1.04, 1.25) compared with the BP-naive controls. BP-exposed also experienced higher rates of aseptic loosening, dislocation, periprosthetic osteolysis, and stress fracture of the femur or hip/pelvis compared to the BP-naive controls, but these values were not statistically significant. CONCLUSION: The use of bisphosphonates in THA patients preoperatively is associated with higher rates of intraoperative and 1-year postoperative complications. These findings may impact the management of patients undergoing THA who have a prior diagnosis of osteoporosis/osteopenia and use of bisphosphonates. LEVEL OF EVIDENCE: Retrospective Cohort Study (Level 3).

Home Health Care Is Associated With an Increased Risk of Emergency Department Visit, Readmission, and Cost of Care Without Reducing Risk of Complication Following Total Hip Arthroplasty: A Propensity-Score Analysis.

BACKGROUND: Home health services have long been implemented for patients to receive additional professional care and supervision following discharge from the hospital to theoretically reduce the risk of complications and health care utilizations. The aim of this investigation was to determine if patients assigned home health services exhibited lower rates of medical and surgical complications, health care utilizations, and costs of care following total hip arthroplasty. METHODS: A large national database was retrospectively reviewed to identify all primary total hip arthroplasty patients from 2010 to 2019. Patients who received home health services were matched using a propensity score algorithm to a set of similar patients who were discharged home under self-care. We compared medical and surgical complication rates, emergency room visits, readmissions, and 90-day costs of care between the groups. Multivariate regression analyses were performed to determine the independent effect of home health services on all outcomes. There were 7,243 patients who received home health services and were matched to 72,430 patients who were discharged home under self-care. RESULTS: Patients who received home health services had higher rates of emergency department visits at 30 days (Odds Ratio [OR] R statistical programming software v 3.6.1 [Lucent Technologies, New Providence, RJ] 1.1544; P = .002) as well as increased readmissions at 30 days (OR 1.137; P = .039); complication rates were similar between groups. Episode-of-care costs for home health patients were higher than those discharged under self-care ($14,236.97 versus $12,817.12; P < .001). CONCLUSION: Patients assigned home health care services exhibited higher costs of care without decreased risk of complications and had increased risk of early returns to the emergency department and readmissions.

Cushing's Syndrome Is Associated With Early Medical- and Surgical-Related Complications Following Total Joint Arthroplasty: A National Database Study.

BACKGROUND: Cushing's syndrome (CS) is a disorder characterized by exposure to supraphysiologic levels of glucocorticoids. The purpose of this study was to evaluate the association between CS and postoperative complication rates following total joint arthroplasty (TJA). METHODS: Patients diagnosed with CS undergoing TJA for degenerative etiologies were identified from a large national database and matched 1:5 to a control cohort using propensity scoring. Propensity score matching resulted in 1,059 total hip arthroplasty (THA) patients with CS matched to 5,295 control THA patients and 1,561 total knee arthroplasty (TKA) patients with CS matched to 7,805 control TKA patients. Rates of medical complications occurring within 90 days of TJA and surgical-related complications occurring within 1 year of TJA were compared using odds ratios (ORs). RESULTS: The THA patients with CS had higher incidences of pulmonary embolism (OR 2.21, P = .0026), urinary tract infection (UTI) (OR 1.29, P = .0417), pneumonia (OR 1.58, P = .0071), sepsis (OR 1.89, P = .0134), periprosthetic joint infection (OR 1.45, P = .0109), and all-cause revision surgery (OR 1.54, P = .0036). The TKA patients with CS had significantly higher incidences of UTI (OR 1.34, P = .0044), pneumonia (OR 1.62, P = .0042), and dislocation (OR 2.43, P = .0049) and a lower incidence of manipulation under anesthesia (MUA) (OR 0.63, P = .0027). CONCLUSION: CS is associated with early medical- and surgical-related complications following TJA and a reduced incidence of MUA following TKA.

Barriers and facilitators to deprescribing before surgery: A qualitative study of providers and older adults.

INTRODUCTION: Deprescribing, the collaborative process between providers and patients to streamline medication regimen, may reduce the risk of adverse events following surgery among older adults with multimorbidity. However, barriers and facilitators to deprescribing for surgery has not been explored. METHODS: We conducted a qualitative study of Primary Care Providers (PCP) and patients aged 65 and older who were scheduled for surgery. We used the Theoretical Domains Framework, which informed the interview guide and analysis. RESULTS: A total of 16 participants (n=8 providers, n=8 patients) were included. Themes were regarding: 1) attitudes towards deprescribing before surgery, 2) perceived benefits of deprescribing before surgery, 3) patient-provider relationship and shared decision-making, 4) hope for surgery, 5) barriers to deprescribing before surgery, and 6) preferences for deprescribing follow-up. CONCLUSION: Our study findings regarding provider- and patient-related barriers and facilitators for deprescribing and desired processes before surgery may inform future deprescribing intervention targets before surgery.

Innovative Devices Did Not Provide Superior Total Knee Arthroplasty Outcomes in Post-Operative Rehabilitation: Results From a Four-Arm Randomized Clinical Trial.

BACKGROUND: Orthopedic surgeons face an increasing array of post-TKA (total knee arthroplasty) rehabilitation interventions that entail innovative equipment and devices, but their relative effectiveness remains unknown. The study compared patient outcomes among primary unilateral TKA patients participating in one of 4 post-TKA rehabilitation interventions-a standard-of-care intervention and 3 more recently developed physical therapy interventions. METHODS: The Knee Arthroplasty Rehabilitation Outcomes Study is a 4-arm randomized clinical trial conducted across 15 outpatient rehabilitation clinics. The trial evaluated 4 alternative interventions: (1) a stationary recumbent bike (control intervention); (2) a body weight-adjustable treadmill; (3) a recumbent bike and use of a patterned electrical neuromuscular stimulation device; and (4) a body weight-adjustable treadmill and a patterned electrical neuromuscular stimulation device. The study's outcome measures were patient walking speed and the Knee injury and Osteoarthritis Outcome Score (KOOS) measured at therapy discharge and at follow-up. RESULTS: The study enrolled 363 TKA patients with 90-92 patients in each of the 4 study arms. Participants were similar across the 4 groups: They were about 63 years old, 61% female, 67% white, living at home, overweight (mean body mass index = 31.6), with mostly private insurance (61%) or Medicare (32%). Walking speed was similar at admission and discharge; KOOS scores were similar at admission, discharge, and follow-up across the 4 intervention groups. CONCLUSION: The study found no statistical or clinically meaningful differences across the 4 study arms in walking speed or KOOS outcomes. Clinicians, payers, and policy makers will want to encourage providers and patients to use the least expensive intervention since each provide similar outcomes. TRIAL REGISTRATION: NCT02426190; https://clinicaltrials.gov/ct2/show/NCT02426190?term=NCT02426190&cntry=US&rank=1.

Juvenile Idiopathic Arthritis is Associated With Early Medical and Surgical Complications Following Primary Total Hip Arthroplasty: A National Database Study.

Background: Juvenile idiopathic arthritis (JIA) is an inflammatory arthropathy that classically affects children but can cause long-term deformity to the femoral head and hip joint, which may require an arthroplasty procedure. There is a paucity of data surrounding the medical and surgical outcomes of total hip arthroplasty (THA) in patients with JIA compared to a control cohort. Methods: Patients with JIA who underwent THA from 2010 to 2019 were identified in a large national insurance database. A propensity score matching algorithm was used to obtain a control cohort who did not have JIA based upon age, sex, and Elixhauser Comorbidity Index in a 1:10 ratio. Seven hundred sixty-three patients with JIA and 7434 patients without JIA were identified who underwent THA. Ninety-day medical outcomes, 1-year surgical outcomes, and 90-day return to the emergency department and readmission were calculated. Results: Patients with JIA were at increased risk of 90-day transfusion (odds ratio [OR] 1.79; P < .001), pneumonia (OR 2.68; P < .001), urinary tract infection (OR 2.64; P < .001), and wound disruption (OR 2.72; P < .001), as well as 1-year risk of revision THA (OR 2.27; P < .001), periprosthetic joint infection (OR 2.98; P < .001), periprosthetic fracture (OR 2.93; P < .001), aseptic loosening (OR 3.92; P < .001), dislocation (OR 2.61; P = .001), and debridement, antibiotics, and implant retention procedure (OR 2.71; P < .001). Patients with JIA were also at increased risk of 90-day emergency department visit (OR 2.54; P < .001) and readmission (OR 2.59; P < .001). Conclusions: Patients with JIA were at increased risk of early medical and surgical complications following THA. These findings are imperative for surgeons to consider and may warrant tailored perioperative decision-making to avoid the aforementioned medical and surgical complications.

Scoliosis Without Fusion and Increased Risk of Early Medical and Surgery-Related Complications After Total Hip Arthroplasty: A Propensity-score Analysis.

INTRODUCTION: There is a paucity of literature that examines how the abnormal spinopelvic alignment of scoliosis affects outcomes after total hip arthroplasty (THA) in the absence of a lumbar fusion. METHODS: Patients with a history of scoliosis (idiopathic, adolescent, degenerative, or juvenile) without fusion and those without a history of scoliosis who underwent primary THA were identified using a large national database. Ninety-day incidence of various medical complications, emergency department (ED) visit, and readmission and 1-year incidence of surgery-related complications and cost of care were evaluated in both the scoliosis and control cohorts. Propensity score matching was used to control for patient demographic factors and comorbidities as covariates. RESULTS: After propensity matching, 21,992 and 219,920 patients were identified in the scoliosis and control cohorts, respectively. Patients with scoliosis were at increased risk of several 90-day medical complications, including pulmonary embolism (odds ratio [OR] 1.96; P < 0.001), deep vein thrombosis (1.49; P < 0.001), transfusion (OR, 1.13; P < 0.001), pneumonia (OR, 1.37; P < 0.001), myocardial infarction (OR, 1.38; P = 0.008), sepsis (OR, 1.59; P < 0.001), acute anemia (OR, 1.21; P < 0.001), and urinary tract infection (OR, 1.1; P = 0.001). Patients with a history of scoliosis were at increased 1-year risk of revision (OR, 1.31; P < 0.001), periprosthetic joint infection (OR, 1.16; P = 0.0089), dislocation (OR, 1.581; P < 0.001), and aseptic loosening (OR, 1.39; P < 0.001) after THA. Patients with scoliosis without a history of fusion were more likely to return to the emergency department (OR, 1.26; P < 0.001) and be readmitted (OR, 1.78; P < 0.001) within 90 days of THA. DISCUSSION: Patients with even a remote history of scoliosis without fusion are at increased risk of 90-day medical and surgery-related complications after hip arthroplasty. Hip and spine surgeons should collaborate in future studies to best understand how to optimize these patients for their adult reconstructive procedures.

Previous Extensor Mechanism Repair Is Associated With Increased Rates of Surgical Complications Following Total Knee Arthroplasty: A Propensity-matched Analysis.

Background: Although extensor mechanism failure following total knee arthroplasty (TKA) is a devastating complication and has been heavily studied in the literature, the impact of extensor mechanism rupture and concomitant repair prior to TKA has not previously been evaluated. The purpose of this investigation was to evaluate how quadriceps and/or patellar tendon repairs prior to TKA would impact medical and surgery-related complications following TKA. Methods: The PearlDiver database was retrospectively reviewed to identify all primary TKA patients from 2010 to 2019. Patients who underwent quadriceps or patellar tendon repair prior to TKA were matched using a propensity score algorithm to a control cohort. We compared medical and surgical complication rates, emergency room visits, readmissions, and 90-day cost of care between the groups. Results: A total of 1197 patients underwent extensor mechanism repair prior to TKA and were matched to 11,970 patients who did not undergo repair prior to TKA. Patients who underwent extensor mechanism repair had higher rates of 90-day medical complications, as well as 1-year surgery-related complications including revision TKA (odds ratio [OR] 6.06; P < .001), lysis of adhesions (OR 2.18; P = .026), aseptic loosening (OR 2.21; P = .018), infection (OR 7.58; P < .001), and fracture (OR 8.53; P < .001). Patients with prior extensor mechanism repair were more likely to return to the emergency department (OR 1.66; P < .001) and become readmitted (OR 4.15; P < .001) within 90 days. Conclusions: Patients with previous extensor mechanism repair exhibited higher medical and surgery-related complications, including lysis of adhesions, following TKA than a control cohort. These findings may suggest that patients may require additional surveillance in the early postoperative period to avoid these disastrous complications following primary TKA.

Payor Type is Associated With Increased Rates of Reoperation and Health-care Utilization Following Unicompartmental Knee Arthroplasty: A National Database Study.

Background: Unicompartmental knee arthroplasty (UKA) is a common orthopedic procedure with overall good clinical outcomes; however, more recent literature has identified disparities in treatment access and outcomes based on sociodemographic factors. There is a paucity of literature examining whether payor type, including Medicare, Medicaid, and commercial insurance types, impacts early medical complications and rates of reoperation following a UKA. Methods: Patients with Medicare, Medicaid, or commercial payor type who underwent primary medial or lateral UKA between 2010 and 2019 were identified using a large national database. Ninety-day incidence of emergency department visit and 1-year incidence of revision, revision to arthroplasty, reimbursement, and cost of care were evaluated. Propensity score matching was used to control for patient demographic factors and comorbidities as covariates. Results: Medicaid insurance was associated with an increased risk of emergency room visit (odds ratio [OR] 2.77; P < .001), revision surgery (OR 1.85; P < .001), and conversion to total knee arthroplasty (OR 1.50; P = .0292) compared to commercially insured patients. Medicaid insurance was associated with an increased risk of emergency room visit (OR 3.58; P < .001), revision surgery (OR 1.97; P < .001), and conversion to total knee arthroplasty (OR 1.80; P = .003). Medicaid patients were associated with a higher overall cost of care and lower reimbursement than commercial and Medicare patients (P < .001 and P < .001, respectively). Conclusions: These findings demonstrate that payor type is associated with increased rates of reoperation and health-care utilization following UKA despite controlling for covariates. Additional work is required to understand the complex relationship between socioeconomic status and outcomes to ensure appropriate health-care access for all patients and pursue appropriate risk stratification. Level of Evidence: III, retrospective chart review.

The Use of Continuous Positive Airway Ventilation for Patients With Obstructive Sleep Apnea is Associated With Early Medical and Surgery-related Complications Following Total Hip Arthroplasty: A National Database Study.

Background: The objective of this study was to determine the effect size of the use of continuous positive airway pressure (CPAP), as a surrogate in cases of active and more severe diseases, on early medical and surgery-related complications following total hip arthroplasty (THA) within an obstructive sleep apnea (OSA) patient population. Methods: Patients with OSA who underwent primary THA between 2010 and 2019 were identified using a large national insurance database. Ninety-day incidence of various medical and surgery-related complications and hospital utilization were evaluated for OSA patients who had used CPAP prior to THA and those who did not. Propensity score matching was used to control for patient demographic factors and comorbidities as covariates. Results: Propensity score matching resulted in 7351 OSA patients who had used CPAP within 6 months of primary THA and 7351 OSA patients who had not. Patients who had used CPAP were at increased 90-day risk of medical complications, as well as 1-year risk of periprosthetic fracture (OR 1.5429; P = .0356), osteolysis (OR 2.4488; P = .0237), aseptic loosening (OR 2.4057; P < .001), and dislocation (OR 1.283; P = .016). Conclusions: Our findings suggest that OSA patients on CPAP are at increased risk of several 90-day medical complications, 1-year surgical complications, and health-care utilization compared to OSA patients not recently using CPAP. Level of Evidence: III, Retrospective review.

A biomechanical comparison between robotic and conventional total knee arthroplasty (TKA) in resection accuracy: a meta-analysis on cadaveric specimens.

PURPOSE: Robotic total knee arthroplasty (TKA) has seen a rapid increase in utilization with recent literature suggesting that implant accuracy and resection are better optimized than in conventional TKA. The purpose of this study was to evaluate the biomechanical properties of robotic-assisted versus conventional TKA in minimizing biplanar femoral and tibial resection error in cadaveric specimens. METHODS: A systematic review and meta-analysis was performed by searching through PubMed, Cochrane library, and Embase to identify studies that analyzed the biomechanical properties of robotic assisted and conventional TKA, according to standard PRISMA guidelines. Evaluated outcomes included femoral coronal resection error (deg), femoral sagittal resection error (deg), tibial coronal resection error (deg), and tibial sagittal resection error (deg). RESULTS: Seven studies met inclusion criteria, including a total of 140 cadaveric specimens (robotic: 70, conventional: 70), for resection accuracy between robotic and conventional TKA. Pooled analysis from seven studies revealed a significant difference in femoral coronal and sagittal resection error in favor of robotic systems compared to conventional systems (p < 0.001 & p < 0.001, respectively). The pooled analysis from seven studies revealed a significant difference in tibial sagittal resection error in favor of robotic systems compared to conventional systems following TKA (p = 0.012). Posthoc power analysis revealed a power of 87.2%. CONCLUSION: The use of robotic TKA is associated with lower femoral coronal, lower femoral sagittal and tibial sagittal resection error compared to conventional TKA. It should be noted that these findings are purely biomechanical - surgeons should interpret these findings along with clinical differences between conventional and robotic systems to determine which system is best for each patient.

Statistical Fragility of Venous Thromboembolism Prophylaxis Following Total Joint Arthroplasty.

Background: Statistical fragility is a quantitative measure of the robustness of the statistical conclusions drawn in a study. Although statistical fragility has been comprehensively evaluated in the arthroplasty literature, the statistical fragility of large-scale randomized trials evaluating venous thromboembolism (VTE) prophylaxis has not been evaluated. The purpose of this study was to determine the utility of applying the fragility index (FI) and the fragility quotient (FQ) analysis to randomized controlled trials (RCTs) evaluating VTE prophylaxis following total joint arthroplasty. Methods: A systematic review was performed by searching multiple databases to identify RCTs that evaluated VTE prophylaxis following total joint arthroplasty from 2000 to 2020. The FI was determined by manipulating each reported dichotomous outcome event until a reversal of significance was appreciated with 2 × 2 contingency tables. The associated FQ was determined by dividing the FI by the sample size. Results: Thirty-two RCTs were ultimately included for analysis. The overall FI incorporating all 32 RCTs was only 7 (interquartile range 3-9), suggesting that the reversal of only 7 events is required to change study significance. The associated FQ was determined to be 0.01. Of the RCTs that reported lost-to-follow-up data, the majority of studies had lost-to-follow-up numbers greater than 7. Conclusions: Our findings suggest that RCTs evaluating VTE prophylaxis following total hip arthroplasty and total knee arthroplasty may lack statistical stability as few outcome events are required to reverse the significance of outcomes. Future randomized trials should consider reporting FI and FQ along with the P value analysis to provide better context to the integrity of statistical stability.

Where Do Orthopaedic Surgery Applicants Match on Their Rank Lists? A Survey of Incoming Residents.

The National Resident Matching Program reports match results by rank list position for all specialties in aggregate, but these data have not been previously reported for orthopaedic surgery specifically. The purpose of this study was to determine where orthopaedic applicants match on their rank lists in comparison to the national average for all specialties and to evaluate which factors may influence match results. Methods: This was a cross-sectional survey study distributed to all applicants to a single institution's orthopaedic surgery residency program. Metrics such as match result, USMLE scores, Alpha Omega Alpha (AOA) status, and research productivity, in addition to other applicant-specific traits were captured. Results were stratified by match status and rank list position, with subgroup analyses completed for applicants matching at highly ranked programs (1-3) vs. lower ranked programs (≥ 4). Results: The survey was distributed to 698 applicants with a response rate of 32% (n = 224), with a match rate of 85% (n = 191). Thirty-four percent of respondents matched at their top choice program, 15.2% at their second choice, 9.9% at their third, and 40.8% at their fourth or lower. When comparing the matched to unmatched applicant cohorts, there was a significant difference in number of programs ranked, AOA status, and sex. When comparing applicants who matched at highly ranked (1-3) vs. lower ranked (≥ 4) programs, there was a significant difference in USMLE board scores. Conclusions: Orthopaedic surgery residency applicants are significantly less likely to match at their first choice or within their top 3 choices when compared to the national average for all specialties. Number of contiguous ranks, AOA status, and female sex were found to be associated with successfully obtaining an orthopaedic residency position, whereas USMLE board scores were associated with matching higher on one's rank list, thus resulting in greater match satisfaction. Level of Evidence: III.

Hormone replacement therapy does not increase thrombosis risk following THA: a national database study.

PURPOSE: Hormone replacement therapy (HRT) causes a significant increase in the risk of venous thrombosis. The risk of medical and surgery-related complications among women taking HRT following total hip arthroplasty (THA) is poorly understood, and there are currently no guidelines in place regarding venous thromboembolism prophylaxis in this patient population. The purpose of this study was to evaluate the frequency of early medical and surgery-related complications following THA among women taking HRT. METHODS: Women aged > 40 years of age who underwent primary THA were identified from a retrospective database review. A control group of non-HRT users was matched using propensity scoring to HRT users. Rates of 90-day medical complications and 1-year surgery-related complications were compared between cohorts using odds ratios. Postoperative anticoagulation regimens were also compared. RESULTS: There were 3,936 patients in the HRT cohort who were matched to 39,360 patients not taking HRT. There were no significant differences in rates of DVT (OR 0.94, p = 0.6601) or PE (OR 0.80, p = 0.4102) between cohorts. Patients on HRT were more likely to sustain a dislocation (OR 1.35, p = 0.0269) or undergo revision surgery (OR 1.23, p = 0.0105). HRT patients were more likely to be prescribed warfarin (OR 1.21, p = 0.0001) or enoxaparin (OR 1.18, p = 0.0022) and less likely to be prescribed rivaroxaban (OR 0.62, p < 0.0001) compared to controls. CONCLUSIONS: HRT was not found to be an independent risk factor for thromboembolism following THA. Further research is warranted to better delineate the ideal perioperative medical management of HRT users undergoing THA.

The Use of Continuous Positive Airway Pressure for Patients With Obstructive Sleep Apnea is Associated With Early Medical and Surgery-Related Complications Following Total Knee Arthroplasty: A National Database Study.

Background: Obstructive sleep apnea (OSA) has been shown to increase the risk of complications following total knee arthroplasty (TKA) although prior studies were limited by their ability to stratify OSA patients by disease severity. The objective of this study was to determine the effect size of the use of continuous positive airway pressure (CPAP) on early medical and surgery-related complications following TKA among patients with OSA. Methods: Patients with OSA who underwent primary TKA were identified using the PearlDiver Mariner database. Ninety-day incidences of medical complications and 1-year incidences of surgery-related complications as well as hospital utilization were evaluated for OSA patients who had used CPAP prior to TKA compared to those who did not. Results: CPAP patients were at increased 90-day risk of emergency department presentation (odds ratio [OR] 1.61; P < .0001), hospital admission (OR 1.33; P < .001), ICU admission (OR 1.45, P < .0001), pulmonary embolism (OR 1.68, P < .0001), deep vein thrombosis (OR 1.31, P < .0001), transfusion (OR 1.89, P < .0001), pneumonia (OR 1.63, P < .0001), cerebrovascular accident (OR 1.92, P < .0001), myocardial infarction (OR 1.57, P = .0015), sepsis (OR 1.35, P = .0025), blood loss anemia (OR 1.67, P < .0001), acute kidney injury (OR 1.65, P < .0001), and urinary tract infection (OR 1.99, P < .0001), as well as increased 1-year risk of undergoing revision surgery (OR 1.14, P = .0028), compared to OSA patients not using CPAP. Conclusions: OSA patients on CPAP undergoing TKA have significantly increased complication rates compared to OSA patients not using CPAP. Level of Evidence: III, Retrospective review.

Robotic-assisted technology does not influence functional outcomes among obese and morbidly obese total knee arthroplasty patients.

PURPOSE: Despite benefits of total knee arthroplasty (TKA) on function and quality of life, obese patients have less improved functional outcomes following TKA compared to their normal weight counterparts. Furthermore, obesity is a risk factor for aseptic loosening and revision surgery following TKA. With known benefits of robotic-assisted TKA (RaTKA) in precision and patient satisfaction, we aimed to evaluate the differences in patient reported outcome and early complication rates for patients undergoing RaTKA versus conventional TKA among patients of varying BMI groups. METHODS: This study was a retrospective cohort study of patients who underwent conventional versus RaTKA. Patients were grouped by BMI range (< 30 kg/m2, 30-40 kg/m2, and > 40 kg/m2). Patient-reported outcomes were measured by Oxford Knee Scores and 12-Item Short Form Survey scores preoperatively, 6-month, 1-year, and 2-year postoperatively. Mixed-effects linear models were built for each patient-reported outcome to assess the interaction between type of surgery and BMI while adjusting for known confounders such as demographic variables. RESULTS: A total of 350 patients (n = 186 RaTKA, n = 164 conventional TKA) met inclusion criteria. SF-12 physical scores were significantly higher at 2-year follow-up among non-obese patients compared to obese and morbidly obese patients (p = 0.047). There was no statistically significant interaction between the type of surgery performed (RaTKA versus conventional TKA) and obesity regarding their effects on patient reported outcomes. CONCLUSIONS: This study demonstrates no differences in functional outcomes among patients undergoing RaTKA compared to conventional TKA. Furthermore, obesity had no significant effect on this association. LEVEL OF EVIDENCE: III.