The Frank Stinchfield Award : Total Hip Arthroplasty for Femoral Neck Fracture Is Not a Typical DRG 470: A Propensity-matched Cohort Study

How Fast Should a Total Knee Arthroplasty Be Performed? An Analysis of 140,199 Surgeries

BACKGROUND

Although previous studies have shown that prolonged operative times can lead to an increased risk of complications after total knee arthroplasty (TKA), they only evaluated a few complications. It is also unclear whether a distinctive operative time exists after which complications increase. Therefore, this study was performed to (1) assess whether higher operative time increases the risk of complications within 30 days of TKA and (2) explore the relationship between operative time and various complications to identify possible operative times where complication rates increase.

METHODS

The National Surgical Quality Improvement Project database was queried from 2011 to 2015 to identify 140,199 primary TKAs. The effect of operative time (skin-to-skin) on various medical and surgical complications within 30 days was evaluated using multivariable logistic regression models. Spline regression models were created to further study the relationship between operative time and complications.

RESULTS

After adjusting for confounding factors, longer operative times were associated with higher risks of readmission (P < .001), reoperation (P < .001), surgical site infection (P < .001), wound dehiscence (P < .001), and transfusion (P < .001). The majority of the complications demonstrated an increase throughout the range of operative time, with a slightly pronounced increase in the risk of complications when the operative time was longer than 80 minutes.

CONCLUSION

Prolonged operative times were associated with an increased risk of a number of important complications such as readmissions, reoperations, surgical site infections, and wound complications. Based on our results, an operative time goal of less than 80 minutes is helpful for minimizing these complications after TKA.

Variation in Treatment Patterns Correlate With Resource Utilization in the 30-Day Episode of Care of Displaced Femoral Neck Fractures

BACKGROUND

We evaluated which treatment decisions in the management of displaced femoral neck fractures (FNFs) may associate with measures of resource utilization relevant to a value-based episode-of-care model.

METHODS

A total of 1139 FNFs treated with hip arthroplasty at 7 hospitals were retrospectively reviewed. Treatment choices were procedure (hemiarthroplasty vs total hip arthroplasty [THA]), surgeon training status, admitting service, and time to surgery. Dependent variables were length of stay, discharge disposition, 30-day readmission, and in-hospital mortality. Variation across hospitals was evaluated with analysis of variance and chi-square tests. Treatment choices were evaluated for the dependent variables of interest with univariable and multivariable regression.

RESULTS

There was significant variation between hospitals regarding proportion of cases treated with THA (range = 3.0%-73.2%, P < .001), proportion treated by arthroplasty fellowship-trained surgeons (range = 0%-74.9%, P < .001), proportion admitted to the orthopedic service (range = 2.8%-91.3%, P < .001), mean time to surgery (range = 0.9-2.1 days, P < .001), and proportion of discharge home (range = 63.9%-97.8%, P < .001). Multivariable analysis adjusting for age, gender, and Charlson Comorbidity Index demonstrated correlations between (1) decreased length of stay and admission to orthopedics (B = -1.256, P < .001); (2) lower 30-day readmission and THA (odds ratio [OR] = .376, P = .004), and (3) decreased discharge to a care facility and admission to orthopedics (OR = 0.402, P = <.001), THA (OR = 0.435, P = .002), and treatment by an arthroplasty fellowship-trained surgeon (OR = 0.572, P = .016). None of the treatment variables tested associated with in-hospital mortality.

CONCLUSION

We observed significant variation in the treatment of displaced FNF patients across 7 hospitals and identified treatment choices that associated with resource utilization within the episode of care. Future, prospective study is necessary to understand whether care pathways that adapt some combination of these characteristics may result in more value-based care.

Hip Fractures and the Bundle: A Cost Analysis of Patients Undergoing Hip Arthroplasty for Femoral Neck Fracture vs Degenerative Joint Disease

BACKGROUND

The purpose of this study is to determine whether episode Target Prices in the Bundled Payment for Care Improvement (BPCI) initiative sufficiently match the complexities and expenses expected for patients undergoing hip arthroplasty for femoral neck fracture (FNF) as compared to hip degenerative joint disease (DJD).

METHODS

Claims data under BPCI Model 2 were collected for patients undergoing hip arthroplasty at a single institution over a 2-year period. Payments from the index hospitalization to 90 days postoperatively were aggregated by Medicare Severity Diagnosis-Related Group (469 or 470), indication (DJD vs FNF), and categorized as index procedure, postacute services, and related hospital readmissions. Actual episode costs and Target Prices were compared in both the FNF and DJD cohorts undergoing hip arthroplasty to gauge the cost discrepancy in each group.

RESULTS

A total of 183 patients were analyzed (31 with FNFs, 152 with DJD). In total, the FNF cohort incurred a $415,950 loss under the current episode Target Prices, whereas the DJD cohort incurred a $172,448 gain. Episode Target Prices were significantly higher than actual episode prices for the DJD cohort ($32,573 vs $24,776, P < .001). However, Target Prices were significantly lower than actual episode prices for the FNF cohort ($32,672 vs $49,755, P = .021).

CONCLUSION

Episode Target Prices in the current BPCI model fall dramatically short of the actual expenses incurred by FNF patients undergoing hip arthroplasty. Better risk-adjusting Target Prices for this fragile population should be considered to avoid disincentives and delays in care.

Differences in Post-Operative Outcome Between Conversion and Primary Total Hip Arthroplasty

BACKGROUND

The demand for conversion of prior hip surgery to total hip arthroplasty (conversion THA) is likely to increase as a function of increasing US hip fracture burden in addition to its application in managing other conditions. Thus, outcome analysis is warranted to better inform value-based reimbursement schemes in the era of bundled payments.

METHODS

Via Current Procedural Terminology codes, the National Surgical Quality Improvement Project data files were queried for all patients who underwent primary THA and conversion of previous hip surgery to THA from 2005 to 2014. To better understand the isolated effect of procedure type on adverse outcomes, primary and conversion cohorts were then propensity-score matched via logistic regression modeling. Comparisons of the study's primary outcomes were drawn between matched cohorts. Statistical significance was defined by a P-value less than or equal to .05.

RESULTS

Relative to the primary THA group, the conversion THA group had statistically greater rates of Center Medicare and Medicaid Services (CMS) complications (7.5% vs 4.5%), non-home bound discharge (19.6% vs 14.7%), and longer length of hospital stay. Conversion THA was associated with increased likelihood of CMS complications (odds ratio 1.68, confidence interval 1.39-2.02) and non-home bound discharge (odds ratio 1.41, confidence interval 1.25-1.58). No statistically significant differences in mortality and readmission were detected.

CONCLUSION

The elevated risk for CMS-reported complications, increased length of hospital stay, and non-home bound discharge seen in our study of conversion THA indicates that it is dissimilar to elective primary THA and likely warrants consideration for modified treatment within the Comprehensive Care for Joint Replacement structure in a manner similar to THA for fracture.

Readmission, Reoperation, and Complications: Total Hip vs Total Knee Arthroplasty

BACKGROUND

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are currently grouped under the same Diagnosis-Related Group (DRG). With the introduction of bundled payments, providers are accountable for all the costs incurred during the episode of care, including the costs of readmissions and management of complications. However, it is unclear whether readmission rates and short-term complications are similar in primary THA and TKA.

METHODS

The National Surgical Quality Improvement Project database was queried from 2011 to 2015 to identify 248,150 primary THA/TKA procedures using Current Procedural Terminology codes. After excluding 1602 hip fractures and 5062 bilateral procedures, 94,326 THAs and 147,160 TKAs were included in the study. Length of stay, discharge disposition, and 30-day readmission, reoperation and complication rates were compared between THA and TKA using multivariate regression models.

RESULTS

After adjusting for baseline characteristics, length of stay (P = .055) and discharge disposition (P = .304) were similar between THA and TKA. But the 30-day rates of readmission (P < .001) and reoperation (P < .001) were higher in THA. Of the 18 complications evaluated in the study, 7 were higher in THA, 3 were higher in TKA, and 8 were similar between THA and TKA.

CONCLUSION

THA patients had higher 30-day rates of readmission and reoperation. As both readmissions and reoperations can result in higher episode costs, a common target price for both THA and TKA may be inappropriate. Further studies are required to fully understand the extent of differences in the episode costs of THA and TKA.

Association Between Body Mass Index and Thirty-Day Complications After Total Knee Arthroplasty

BACKGROUND

Although previous studies have evaluated the effect of obesity on the outcomes of total knee arthroplasty (TKA), most considered obesity as a binary variable. It is important to compare different weight categories and consider body mass index (BMI) as a continuous variable to understand the effects of obesity across the entire range of BMI. Therefore, the objective of this study is to analyze the effect of BMI on 30-day readmissions and complications after TKA, considering BMI as both a categorical and a continuous variable.

METHODS

The National Surgical Quality Improvement Project database was queried from 2011 to 2015 to identify 150,934 primary TKAs. Thirty-day rates of readmissions, reoperations, and medical/surgical complications were compared between different weight categories (overweight: BMI >25 and ≤30 kg/m²; obese: BMI >30 and ≤40 kg/m²; morbidly obese: BMI >40 kg/m²) and the normal weight category (BMI >18.5 and ≤25 kg/m²) using multivariate regression models. Spline regression models were created to study BMI as a continuous variable.

RESULTS

Obese patients were at increased risk of pulmonary embolism (PE) (P < .001), while morbidly obese patients were at increased risk of readmission (P < .001), reoperation (P < .001), superficial infection (P < .001), periprosthetic joint infection (P < .001), wound dehiscence (P < .001), PE (P < .001), urinary tract infection (P = .003), reintubation (P = .004), and renal insufficiency (P < .001). Transfusion was lower in overweight (P < .001), obese (P < .001), and morbidly obese (P < .001) patients. BMI had a nonlinear relationship with readmission (P < .001), reoperation (P < .001), periprosthetic joint infection (P = .041), PE (P < .001), renal insufficiency (P = .046), and transfusion (P < .001).

CONCLUSION

Obesity increased the risk of readmission and various complications after TKA, with the risk being dependent on the severity of obesity. Relationships between BMI and complications showed considerable variations with some outcomes like readmission and reoperation showing a U-shaped relationship. Based on our findings, a potential BMI goal in weight management for obese patients could be established around 29-30 kg/m², in order to decrease the risk of most TKA postoperative complications.

Refining Risk Adjustment for the Proposed CMS Surgical Hip and Femur Fracture Treatment Bundled Payment Program

BACKGROUND

The U.S. Centers for Medicare & Medicaid Services (CMS) has been considering the implementation of a mandatory bundled payment program, the Surgical Hip and Femur Fracture Treatment (SHFFT) model. However, bundled payments without appropriate risk adjustment may be inequitable to providers and may restrict access to care for certain patients. The SHFFT proposal includes adjustment using the Diagnosis-Related Group (DRG) and geographic location. The goal of the current study was to identify and quantify patient factors that could improve risk adjustment for SHFFT bundled payments.

METHODS

We retrospectively reviewed a 5% random sample of Medicare data from 2008 to 2012. A total of 27,898 patients were identified who met SHFFT inclusion criteria (DRG 480, 481, and 482). Reimbursement was determined for each patient over the bundle period (the surgical hospitalization and 90 days of post-discharge care). Multivariable regression was performed to test demographic factors, comorbidities, geographic location, and specific surgical procedures for associations with reimbursement.

RESULTS

The average reimbursement was $23,632 ± $17,587. On average, reimbursements for male patients were $1,213 higher than for female patients (p < 0.01). Younger age was also associated with higher payments; e.g., reimbursement for those ≥85 years of age averaged $2,282 ± $389 less than for those aged 65 to 69 (p < 0.01). Most comorbidities were associated with higher reimbursement, but dementia was associated with lower payments, by an average of $2,354 ± $243 (p < 0.01). Twenty-two procedure codes are included in the bundle, and patients with the 3 most common codes accounted for 98% of the cases, with average reimbursement ranging from $22,527 to $24,033. Less common procedures varied by >$20,000 in average reimbursement (p < 0.01). DRGs also showed significant differences in reimbursement (p < 0.01); e.g., DRG 480 was reimbursed by an average of $10,421 ± $543 more than DRG 482. Payments varied significantly by state (p ≤ 0.01). Risk adjustment incorporating specific comorbidities demonstrated better performance than with use of DRG alone (r = 0.22 versus 0.15).

CONCLUSIONS

Our results suggest that the proposed SHFFT bundled payment model should use more robust risk-adjustment methods to ensure that providers are reimbursed fairly and that patients retain access to care. At a minimum, payments should be adjusted for age, comorbidities, demographic factors, geographic location, and surgical procedure.

Same-Day Discharge Compared with Inpatient Hospitalization Following Hip and Knee Arthroplasty

BACKGROUND

Discharge from the hospital on the day of (same-day) hip and knee arthroplasties has become more common; however, to our knowledge, few studies have compared morbidity between same-day and inpatient surgical procedures. The aims of this study were to compare matched cohorts of patients who underwent same-day and inpatient hip or knee arthroplasty in terms of postoperative complications and 30-day readmission rates.

METHODS

Patients who underwent primary elective total hip arthroplasty, total knee arthroplasty, or unicompartmental knee arthroplasty from 2005 to 2014 were identified from the National Surgical Quality Improvement Program registry. Patients discharged the day of the surgical procedure were matched 1:1 with patients who had an inpatient stay using propensity scores. The rates of 30-day adverse events and readmission were compared between matched cohorts using the McNemar test. Risk factors for 30-day readmission following same-day procedures were identified using multivariate regression.

RESULTS

Of 177,818 patients identified, 1,236 (0.70%) underwent a same-day surgical procedure. After matching, there were no differences in overall adverse events or readmission between same-day and inpatient groups, although inpatients had increased thromboembolic events (p = 0.048) and same-day patients had an increased rate of return to the operating room (p = 0.016). When procedures were assessed individually, the only difference identified was that the same-day total knee arthroplasty cohort had an increased return to the operating room compared with the inpatient total knee arthroplasty cohort (p = 0.046). Body mass index of ≥35 kg/m (p = 0.035), insulin-dependent diabetes (p = 0.041), non-insulin-dependent diabetes (p = 0.013), and age of ≥85 years (p = 0.039) were associated with 30-day readmission following same-day surgical procedures. Infection was the most common reason for reoperation and readmission following same-day procedures.

CONCLUSIONS

No significant differences in overall postoperative complications or readmission were found between matched cohorts of patients who underwent same-day and inpatient hip and knee arthroplasties, although inpatients had a higher rate of thromboembolic events and same-day patients had a higher rate of reoperation. Patients with a body mass index of ≥35 kg/m, diabetes, and an age of ≥85 years had an increased risk of 30-day readmission following same-day procedures, which was most commonly due to infection.

LEVEL OF EVIDENCE

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

Femoral Nerve Catheters Improve Home Disposition and Pain in Hip Fracture Patients Treated With Total Hip Arthroplasty

BACKGROUND

Opioids have been the mainstay of treatment in the physiologically young geriatric hip fracture patient undergoing total hip arthroplasty (THA). However opioid-related side effects increase morbidity. Regional anesthesia may provide better analgesia, while decreasing opioid-related side effects. The goal of this study was to examine the effect of perioperative continuous femoral nerve blockade with regards to pain scores, opioid-related side effects and posthospital disposition in hip fracture patients undergoing THA.

METHODS

Twenty-nine consecutive geriatric hip fracture patients (22 women/7 men) underwent THA. Average follow-up was 8.3 months (6 weeks-39 months). Fifteen patients were treated with standard analgesia (SA). Fourteen patients received an ultrasound-guided insertion of a femoral nerve catheter after radiographic confirmation of a hip fracture. All complications and readmissions that occurred within 6 weeks of surgery were noted.

RESULTS

Continuous femoral nerve catheter (CFNC) patients were discharged home more frequently than SA patients (43% for CFNC vs 7% for SA; P = .023). CFNC patients reported lower average pain scores preoperatively (P < .0001), on postoperative day 1 (P = .005) and postoperative day 2 (P = .037). Preoperatively, CFNC patients required 61% less morphine equivalent (P = .007). CFNC patients had a lower rate of opioid-related side effects compared with SA patients (7% vs 47%; P = .035).

CONCLUSION

CFNC patients were discharged to home more frequently. Use of a CFNC decreased daily average patient-reported pain scores, preoperative opioid usage, and opioid-related side effects after THA for hip fracture. Based on these data, we recommend routine use of perioperative CFNC in hip fracture patients undergoing THA.

The Lawrence D. Dorr Surgical Techniques & Technologies Award: Differences in Postoperative Outcomes Between Total Hip Arthroplasty for Fracture vs Osteoarthritis

BACKGROUND

Hip fracture is an increasingly common expanded indication for total hip arthroplasty (THA) and warrants outcome analysis so as to best inform risk assessment models, public reporting of outcome, and value-based reimbursement schemes.

METHODS

The National Surgical Quality Improvement Program data file from 2011 to 2014 was used to identify all patients undergoing THA via current procedural terminology code 27130. Propensity score matching in a 1:5 fashion was used to compare 2 cohorts: THA for osteoarthritis and THA for fracture. Primary outcomes included Centers for Medicare and Medicaid Services (CMS) reportable complications, unplanned readmission, postsurgical length of stay, and discharge destination. χ² tests for categorical variables and Student t test for continuous variables were used to compare the 2 cohorts and adjusted linear regression analysis used to determine the association between hip fracture and THA outcomes of interest.

RESULTS

A total of 58,302 patients underwent elective THA for osteoarthritis and 1580 patients underwent THA for hip fracture. Rates of CMS-reported complications (4.0% vs 10.7%; P < .001), non-homebound discharge (39.8% vs 64.7%; P < .001), readmission (4.7% vs 8.0%; P < .001), and mean days of postsurgical hospital stay (3.2 vs 4.4; P < .001) were greater in the hip fracture cohort. THA for hip fracture was significantly associated with increased risk of CMS-reportable complications (odds ratio [OR], 2.67; 95% confidence interval [CI], 2.17-3.28), non-homebound discharge (OR, 1.73; 95% CI, 1.39-2.15), and readmission (OR, 2.78; 95% CI, 2.46-3.12).

CONCLUSION

Our findings support recent advocacy for the exclusion of THA for fracture from THA bundled pricing methodology and public reporting of outcomes.

Hip Arthroplasty for Fracture vs Elective Care: One Bundle Does Not Fit All

BACKGROUND

To quantify how baseline differences in patients undergoing hip arthroplasty for fracture vs elective care potentially lead to significant differences in immediate health care outcomes and whether these differences affect feasibility of current bundled payment models.

METHODS

New York Statewide Planning and Research Cooperative System database for the years 2000-2014.

RESULTS

A total of 76,654 patients underwent total hip arthroplasty or hemiarthroplasty between 2010 and 2014; 82.8% of the sample was for elective care and 17.2% for fracture-related etiology. Fracture patients were significantly older, more likely to be female, Caucasian, reimbursed by Medicare, and receive general anesthesia. Comorbidity burden and postoperative complications were significantly higher in the fracture group, and hospital charges were significantly greater for fracture patients as compared with those of the elective cohort.

CONCLUSION

Patients undergoing hip arthroplasty for fracture care are significantly older and have more medical comorbidities than patients treated on an elective basis, leading to more in-hospital complications, greater length of stay, increased hospital costs, and significantly more hospital readmissions. The present bundled payment system, even with the recent modification, still unfairly penalizes hospitals that manage fracture patients and has the potential to incentivize hospitals to defer providing definitive surgical management for these patients. Future amendments to the bundled payment system should consider further separating hip arthroplasty patients based on etiology and comorbidities, allowing for a more accurate reflection of these distinct patient groups.

Short-Term Outcomes Following Hip Fractures in Patients at Least 100 Years Old

BACKGROUND

The number of hip fractures is rising as life expectancy increases. As such, the number of centenarians sustaining these fractures is also increasing. The purpose of this study was to determine whether patients who are ≥100 years old and sustain a hip fracture fare worse in the hospital than those who are younger.

METHODS

Using a large database, the New York Statewide Planning and Research Cooperative System (SPARCS), we identified patients who were ≥65 years old and had been treated for a hip fracture over a 12-year period. Data on demographics, comorbidities, and treatment were collected. Three cohorts were established: patients who were 65 to 80 years old, 81 to 99 years old, and ≥100 years old (centenarians). Outcome measures included hospital length of stay, estimated total costs, and in-hospital mortality rates.

RESULTS

A total of 168,087 patients with a hip fracture were identified, and 1,150 (0.7%) of them had sustained the fracture when they were ≥100 years old. Centenarians incurred costs and had lengths of stay that were similar to those of younger patients. Despite the similarities, centenarians were found to have a significantly higher in-hospital mortality rate than the younger populations (7.4% compared with 4.4% for those 81 to 99 years old and 2.6% for those 65 to 80 years old; p < 0.01). Male sex and an increasing number of medical comorbidities were found to predict in-hospital mortality for centenarians sustaining extracapsular hip fractures. No significant predictors of in-hospital mortality were identified for centenarians who sustained femoral neck fractures. An increased time to surgery did not influence the odds of in-hospital mortality.

CONCLUSIONS

Centenarians had increased in-hospital mortality, but the remaining short-term outcomes were comparable with those for the younger cohorts with similar fracture patterns. For this extremely elderly population, time to surgery does not appear to affect short-term mortality rates, suggesting a potential benefit to preoperative optimization.

LEVEL OF EVIDENCE

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

The Association Between Hospital Length of Stay and 90-Day Readmission Risk for Femoral Neck Fracture Patients: Within a Total Joint Arthroplasty Bundled Payment Initiative

BACKGROUND

Hip arthroplasty is increasingly performed as a treatment for femoral neck fractures (FNFs). However, these cases have higher complication rates than elective total hip arthroplasties (THAs). The Center for Medicare and Medicaid Services has created the Comprehensive Care for Joint Replacement model to increase the value of patient care. This model risk stratifies FNF patients in an attempt to appropriately allocate resources, but the formula has not been disclosed. The goal of this study was to ascertain if patients with FNFs have different readmission rates compared to patients undergoing elective THA so that the resource utilization can be assessed.

METHODS

We analyzed all patients undergoing THA at our institution during a 21-month period. Patients classified by a diagnosis-related group of 469 or 470 were included. Multivariate and survival analyses were performed to determine risk of 90-day readmission.

RESULTS

Patients admitted for FNFs were older, had higher body mass indices, longer lengths of stay, and were more likely to be discharged to inpatient facilities than patients who underwent elective THA. Increased American Society of Anesthesiologists scores and FNF were also independent risk factors for 90-day readmission, and these patient were more likely to be readmitted during the latter 60 days following admission.

CONCLUSION

Results suggest that patients who undergo an arthroplasty following urgent or emergent FNFs have inferior outcomes to those receiving an arthroplasty for a diagnosis of arthritis. Fracture patients should either be risk stratified to allow appropriate resource allocation or be excluded from alternative payment initiatives such as Comprehensive Care for Joint Replacement.