Can Abnormal Spinopelvic Relationships be Identified by Anteroposterior Pelvic Radiographs?

BACKGROUND: Abnormal spinopelvic relationships may place patients at an increased risk for instability after primary total hip arthroplasty. The purpose of this study was to determine if radiographic markers on a standing anteroposterior (AP) pelvis radiograph could identify patients with sagittal spinopelvic imbalance or spinal stiffness. METHODS: Patients undergoing primary total hip arthroplasty at a single institution from 2017 to 2020 with standing AP pelvis radiographs and sitting/standing lateral radiographs were identified. AP pelvis radiographs were assessed for the following: lumbosacral hardware, spine osteophytes, disc space narrowing, scoliosis>5°, pelvic obliquity>5°, and overlap of the sacrococcygeal junction/pubic symphysis. Patients with spinopelvic imbalance and/or spinopelvic stiffness were identified. Univariate and multivariate analyses were performed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: Four hundred eighty-six patients were included. Prevalence of isolated sagittal spinopelvic imbalance and isolated spinopelvic stiffness was 12% and 21%, respectively; 11% of patients had sagittal imbalance and stiffness. Overlap of the sacrococcygeal junction/pubic symphysis (OR = 10.2, 95% CI = 5.3-19.8) and presence of lumbosacral hardware (OR = 4.4, 95% CI = 2.0-9.4) were markers of an increased risk of combined sagittal imbalance and stiffness. Seventy-nine percent of patients with overlap of the sacrococcygeal junction and pubic symphysis and 82% of patients with lumbosacral hardware had an abnormal spinopelvic relationship. CONCLUSION: Isolated sagittal imbalance and stiffness were difficult to predict on standing AP pelvis radiographs. Overlap of the sacrococcygeal junction/pubic symphysis and presence of lumbosacral hardware associated with a higher risk of combined sagittal imbalance/stiffness and were present in ≥79% of patients with an abnormal spinopelvic relationship. LEVEL OF EVIDENCE: IV; retrospective cohort study.

Observed Differences in Patient Comorbidities and Complications Undergoing Primary Total Joint Arthroplasty Between Non-orthopaedic and Orthopaedic Referral Patients.

BACKGROUND: Value-based total joint arthroplasty (TJA) has resulted in decreasing surgeon reimbursement which has created concern that surgeons are being incentivized to avoid medically complex patients. The purpose of this study was to determine if patients who underwent primary total knee (TKA) and total hip arthroplasty (THA) had different comorbidities and complication rates based on referral type: 1) non-orthopaedic referral (NOR), 2) outside orthopaedic referral (OOR) or 3) self-referral (SR). METHODS: At a single tertiary care centre, patients undergoing primary TJA between July 2019 and January 2020 were identified using current procedural codes. Data were abstracted from the Institutional National Surgical Quality Improvement Program (NSQIP) along with electronic medical records which included referral type, primary insurance, demographics, comorbidities, and comorbidity scores, including an American Society of Anesthesiology (ASA) score. Complications and outcomes were tracked for 90 days post-operatively. Referral groups were compared using Chi-square exact tests for categorical variables and t-tests or Wilcoxon Rank Sum tests for continuous variables, as appropriate. RESULTS: Of the 393 patients included in this study, there were 249 (63%) NOR, 104 (26%) OOR, and 40 (10%) SR. The OOR versus NOR group had a significantly greater proportion of patients with obesity (79 vs 64%, p=0.047) and an ASA score ≥3 (59 vs 43%, p=0.007). There was a significantly greater proportion of patients with wound complications (10 vs 4%, p=0.023) and ≥2 complications (14 vs 3%, p<0.001) in OOR versus NOR, respectively. CONCLUSION: Patients who underwent primary TJA and were referred by an orthopaedic surgeon tended to have more comorbid conditions and higher rates of severe complications. The observed difference in referrals may be explained by monetary incentivization in the context of current reimbursement trends. Organizations utilizing bundled payment programs to reimburse surgeons should use a risk-stratification model to mitigate incentivizing surgeons to avoid medically complex patients.

Discordance in Published 30-Day Readmission Rates Following Primary Total Hip and Total Knee Arthroplasty: Centers for Medicare and Medicaid Services (CMS) Versus the National Surgical Quality Improvement Program (NSQIP).

Background: 30-day readmission is an important quality metric evaluated following primary total joint arthroplasty (TJA) that has implications for hospital performance and reimbursement. Differences in how 30-day readmissions are defined between Centers for Medicare and Medicaid Services (CMS) and other quality improvement programs (i.e., National Surgical Quality Improvement Program [NSQIP]) may create discordance in published 30-day readmission rates. The purpose of this study was to evaluate 30-day readmission rates following primary TJA using two different temporal definitions. Methods: Patients undergoing primary total hip and primary total knee arthroplasty at a single academic institution from 2015-2020 were identified via common procedural terminology (CPT) codes in the electronic medical record (EMR) and institutional NSQIP data. Readmissions that occurred within 30 days of surgery (consistent with definition of 30-day readmission in NSQIP) and readmissions that occurred within 30 days of hospital discharge (consistent with definition of 30-day readmission from CMS) were identified. Rates of 30-day readmission and the prevalence of readmission during immortal time were calculated. Results: In total, 4,202 primary TJA were included. The mean hospital length of stay (LOS) was 1.79 days. 91% of patients were discharged to home. 30-day readmission rate using the CMS definition was 3.1% (130/4,202). 30-day readmission rate using the NSQIP definition was 2.7% (113/4,202). Eight readmissions captured by the CMS definition (6.1%) occurred during immortal time. Conclusion: Differences in temporal definitions of 30-day readmission following primary TJA between CMS and NSQIP results in discordant rates of 30-day readmission. Level of Evidence: III.

How Many Patients Qualify for Extended Oral Antibiotic Prophylaxis Infection Following Primary and Revision Hip and Knee Arthroplasties?

Extended oral antibiotic prophylaxis (EOAP) has been suggested to reduce rates of periprosthetic joint infection (PJI) postoperatively after total joint arthroplasty (TJA). The purpose of this multicenter study is to define how many TJA patients are considered high risk for developing PJI based on published EOAP criteria and determine whether this status is associated with socioeconomic or demographic factors. All primary and aseptic revision TJAs performed in 2019 at three academic medical centers were reviewed. High-risk status was defined based on prior published EOAP criteria. Area deprivation index (ADI) was calculated as a measure of socioeconomic status. Data were reported as means with standard deviation. Both overall and institutional differences were compared. Of the 2,511 patients (2,042 primary and 469 revision) in this cohort, 73.3% met criteria for high risk (primary: 72.9% [1,490] and revision: 74.6% [350]). Patient's race or age did not have a significant impact on risk designation; however, a larger proportion of high-risk patients were women (p = 0.002) and had higher Elixhauser scores (p < 0.001). The mean ADI for high-risk patients was higher (more disadvantaged) than for standard-risk patients (64.0 [20.8] vs. 59.4 [59.4]) (p < 0.001). Over 72% of primary and revision TJA patients at three medical centers met published criteria for EOAP. These patients were more often women, had more comorbidities, and lived in more disadvantaged areas. Our findings suggest that most patients qualify for EOAP, which may call for more stringent criteria on who would benefit extended antibiotic prophylaxis.