Understanding the causes of failure and the types of revision total hip arthroplasty performed is essential for guiding research, implant design, clinical decision-making, and health-care policy. The ...purpose of the present study was to evaluate the mechanisms of failure and the types of revision total hip arthroplasty procedures performed in the United States with use of newly implemented ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) diagnosis and procedure codes related specifically to revision total hip arthroplasty in a large, nationally representative population.
The Healthcare Cost and Utilization Project Nationwide Inpatient Sample database was used to analyze clinical, demographic, and economic data from 51,345 revision total hip arthroplasty procedures performed between October 1, 2005, and December 31, 2006. The prevalence of revision procedures was calculated for population subgroups in the United States that were stratified according to age, sex, diagnosis, census region, primary payer class, and type of hospital. The cause of failure, the average length of stay, and total charges were also determined for each type of revision arthroplasty procedure.
The most common type of revision total hip arthroplasty procedure performed was all-component revision (41.1%), and the most common causes of revision were instability/dislocation (22.5%), mechanical loosening (19.7%), and infection (14.8%). Revision total hip arthroplasty procedures were most commonly performed in large, urban, nonteaching hospitals for Medicare patients seventy-five to eighty-four years of age. The average length of hospital stay for all types of revision arthroplasties was 6.2 days, and the average total charges were $54,553. However, the average length of stay, average charges, and procedure frequencies varied considerably according to census region, hospital type, and type of revision total hip arthroplasty procedure performed.
Hip instability and mechanical loosening are the most common indications for revision total hip arthroplasty in the United States. As further experience is gained with the new diagnosis and procedure codes specifically related to revision total hip arthroplasty, this information will be valuable in directing future research, implant design, and clinical decision-making.
Abstract Introduction The purpose of this study was to evaluate the changing incidence of hip arthroscopy procedures among newly trained surgeons in the United States, the indications for hip ...arthroscopy, and the reported rate of post-operative complications. Methods The ABOS database was used to evaluate the annual incidence of hip arthroscopy procedures between 2006–2010. Procedures were categorized by indication and type of procedure. The rate of surgical complications was calculated and compared between the published literature and hip arthroscopy procedures performed for femoroacetabular impingement (FAI)/osteoarthritis (OA) and for labral tears among the newly trained surgeon cohort taking the ABOS Part II Board exam. Results The overall incidence of hip arthroscopy procedures performed by ABOS Part II examinees increased by over 600% during the 5-year period under study from approximately 83 in 2006 to 636 in 2010. The incidence of hip arthroscopy for FAI/OA increased steadily over the time period under study, while the incidence of hip arthroscopy for labral tears was variable over time. The rate of surgical complications was 5.9% for hip arthroscopy procedures for a diagnosis of FAI/OA vs. 4.4% for a diagnosis of labral tear ( P = 0.36). Conclusions The incidence of hip arthroscopy has increased dramatically over the past 5 years, particularly for the indication of FAI/OA. Reported surgical complication rates are relatively low, but appear higher than those rates reported in previously published series. Appropriate indications for hip arthroscopy remain unclear.
Abstract Periprosthetic joint infection (PJI) represents substantial clinical and economic burdens. This study evaluated patient and procedure characteristics and resource utilization associated with ...revision arthroplasty for PJI. The Nationwide Inpatient Sample (Q4 2005–2010) was analyzed for 235,857 revision THA (RTHA) and 301,718 revision TKA (RTKA) procedures. PJI was the most common indication for RTKA, and the third most common reason for RTHA. PJI was most commonly associated with major severity of illness (SOI) in RTHA, and with moderate SOI in RTKA. RTHA and RTKA for PJI had the longest length of stay. Costs were higher for RTHA/RTKA for PJI than for any other diagnosis except periprosthetic fracture. Epidemiologic differences exist in the rank, severity and populations for RTHA and RTKA for PJI.
Background
Revision THA and TKA are growing and important clinical and economic challenges. Healthcare systems tend to combine revision joint replacement procedures into a single service line, and ...differences between revision THA and revision TKA remain incompletely characterized. These differences carry implications for guiding care and resource allocation. We therefore evaluated epidemiologic trends associated with revision THAs and TKAs.
Questions/purposes
We sought to determine differences in (1) the number of patients undergoing revision TKA and THA and respective demographic trends; (2) differences in the indications for and types of revision TKA and THA; (3) differences in patient severity of illness scoring between THA and TKA; and (4) differences in resource utilization (including cost and length of stay LOS) between revision THA and TKA.
Methods
The Nationwide Inpatient Sample (NIS) was used to evaluate 235,857 revision THAs and 301,718 revision TKAs between October 1, 2005 and December 31, 2010. Patient characteristics, procedure information, and resource utilization were compared across revision THAs and TKAs. A revision burden (ratio of number of revisions to total number of revision and primary surgeries) was calculated for hip and knee procedures. Severity of illness scoring and cost calculations were derived from the NIS. As our study was principally descriptive, statistical analyses generally were not performed; however, owing to the large sample size available to us through this NIS analysis, even small observed differences presented are likely to be highly statistically significant.
Results
Revision TKAs increased by 39% (revision burden, 9.1%–9.6%) and THAs increased by 23% (revision burden, 15.4%–14.6%). Revision THAs were performed more often in older patients compared with revision TKAs. Periprosthetic joint infection (25%) and mechanical loosening (19%) were the most common reasons for revision TKA compared with dislocation (22%) and mechanical loosening (20%) for revision THA. Full (all-component) revision was more common in revision THAs (43%) than in TKAs (37%). Patients who underwent revision THA generally were sicker (> 50% major severity of illness score) than patients who underwent revision TKA (65% moderate severity of illness score). Mean LOS was longer for revision THAs than for TKAs. Mean hospitalization costs were slightly higher for revision THA (USD 24,697 +/− USD 40,489 SD) than revision TKA (USD 23,130 +/− USD 36,643 SD). Periprosthetic joint infection and periprosthetic fracture were associated with the greatest LOS and costs for revision THAs and TKAs.
Conclusions
These data could prove important for healthcare systems to appropriately allocate resources to hip and knee procedures: the revision burden for THA is 52% greater than for TKA, but revision TKAs are increasing at a faster rate. Likewise, the treating clinician should understand that while both revision THAs and TKAs bear significant clinical and economic costs, patients undergoing revision THA tend to be older, sicker, and have greater costs of care.
Orthopaedic fellowships first gained popularity in the U.S. in the 1970s, and since that time, the percentage of orthopaedic residency graduates pursuing subspecialty fellowship training has ...increased. Prior reports have shown an increase in subspecialization from 1988 through 2002; however, the current number and proportion of graduates pursuing fellowship training since 2002 are unknown. The purpose of this study was to determine the percentage of recent graduates who pursue fellowship training and the proportion of procedures that these graduates perform within their area of fellowship training.
Data from the American Board of Orthopaedic Surgery Part II examination for board certification were used to determine the number and percentage of fellowship-trained and non-fellowship-trained applicants from 2003 to 2013. The percentage of cases performed by fellowship-trained applicants within their area of fellowship training was calculated and was analyzed as a function of time and a function of fellowship training category. Linear regression was used to determine trend as a function of time.
The percentage of fellowship-trained applicants increased from 76% in 2003 to 90% in 2013. Of the 1,257,161 procedures performed by fellowship-trained applicants, 981,077 (78%) were performed within the surgeon's area of fellowship training. Spine and hand-trained applicants performed more than 85% of their procedures within their area of fellowship training.
From 2003 to 2013, the percentage of fellowship-trained applicants taking the American Board of Orthopaedic Surgery Part II examination gradually increased to 90%. In the same time period, fellowship-trained surgeons performed an increasing proportion of procedures within their area of subspecialty training. Orthopaedic graduates have become increasingly subspecialized over the past decade.
The patient-related risk factors for periprosthetic joint infection and postoperative mortality in elderly patients undergoing total hip arthroplasty are poorly understood. The purpose of this study ...was to identify the specific patient comorbidities that are associated with an increased risk of periprosthetic joint infection and of ninety-day postoperative mortality in U.S. Medicare patients undergoing total hip arthroplasty.
The Medicare 5% sample claims database was used to calculate the relative risk of periprosthetic joint infection and of ninety-day postoperative mortality as a function of preexisting comorbidities in 40,919 patients who underwent primary total hip arthroplasty between 1998 and 2007. The impact of twenty-nine comorbid conditions on periprosthetic joint infection and on postoperative mortality was examined with use of Cox regression, controlling for age, sex, census region, public assistance, and all other baseline comorbidities. The adjusted hazard ratios for all comorbid conditions were evaluated, and the Wald chi-square statistic was used to rank the degree of association of each condition with periprosthetic joint infection and with postoperative mortality. The Bonferroni-Holm method was used to adjust for the multiple comparisons resulting from the number of comorbid conditions analyzed.
Comorbid conditions associated with an increased adjusted risk of periprosthetic joint infection (in decreasing order of significance, p < 0.05 for all comparisons) were rheumatologic disease (hazard ratio HR = 1.71), obesity (HR = 1.73), coagulopathy (HR = 1.58), and preoperative anemia (HR = 1.36). Comorbid conditions associated with an increased adjusted risk of ninety-day postoperative mortality (in decreasing order of significance, p < 0.05 for all comparisons) were congestive heart failure (HR = 2.11), metastatic cancer (HR = 3.14), psychosis (HR = 1.85), renal disease (HR = 1.98), dementia (HR = 2.04), hemiplegia or paraplegia (HR = 2.62), cerebrovascular disease (HR = 1.40), and chronic pulmonary disease (HR = 1.32).
We identified specific patient comorbidities that were independently associated with an increased risk of periprosthetic joint infection and of ninety-day postoperative mortality in Medicare patients who had undergone total hip arthroplasty. This information is important when counseling elderly patients regarding the risks of periprosthetic joint infection and mortality following total hip arthroplasty, as well as for risk adjustment of publicly reported total hip arthroplasty outcomes.
Understanding the cause of failure and type of revision total knee arthroplasty (TKA) procedures performed in the United States is essential in guiding research, implant design, and clinical decision ...making in TKA. We assessed the causes of failure and specific types of revision TKA procedures performed in the United States using newly implemented ICD-9-CM diagnosis and procedure codes related to revision TKA data from the Nationwide Inpatient Sample (NIS) database. Clinical, demographic, and economic data were reviewed and analyzed from 60,355 revision TKA procedures performed in the United States between October 1, 2005 and December 31, 2006. The most common causes of revision TKA were infection (25.2%) and implant loosening (16.1%), and the most common type of revision TKA procedure reported was all component revision (35.2%). Revision TKA procedures were most commonly performed in large, urban, nonteaching hospitals in Medicare patients ages 65 to 74. The average length of hospital stay (LOS) for all revision TKA procedures was 5.1 days, and the average total charges were $49,360. However, average LOS, average charges, and procedure frequencies varied considerably by census region, hospital type, and procedure performed.
Level of Evidence:
Level II, economic and decision analysis. See Guidelines for Authors for a complete description of levels of evidence.
Purpose To analyze a large national private payer population in the United States for trends over time in hip arthroscopy by age groups and to determine the rate of conversion to total hip ...arthroplasty (THA) after hip arthroscopy. Methods We performed a retrospective analysis using the PearlDiver private insurance patient record database from 2007 through 2011. Hip arthroscopy procedures including newly introduced codes such as osteochondroplasty of cam and pincer lesions and labral repair were queried. Hip arthroscopy incidence and conversion rates to THA were stratified by age. Chi-squared analysis was used for statistical comparison. Conversion to THA was evaluated using Kaplan-Meier analysis. Results From 2007 through 2011, 20,484,172 orthopaedic patients were analyzed. Hip arthroscopy was performed in 8,227 cases (mean annual incidence, 2.7 cases per 10,000 orthopaedic patients). The incidence of hip arthroscopies increased over 250% from 1.6 cases per 10,000 in 2007 to 4.0 cases per 10,000 in 2011 ( P < .0001). Patients in the 40 to 49 age group made up 28% of cases, followed by patients ages 30 to 39 (22%) and 50 to 59 (19%). Patients under 30 years old showed the greatest increase in incidence from 2007 to 2011 (335%), but patients over 60 still had over a 200% increase. Labral debridement was the most common procedure (6,031 cases), and approximately 1.6 procedural codes were billed for every case performed. Labral repair was more common in patients under 30, while labral debridement was more common in older age groups ( P = .046). Within 24 months of hip arthroscopy, 17% of patients older than 50 required conversion to THA, compared with <1% of patients under 30 ( P < .0001). Conclusions Hip arthroscopy procedures are increasing in popularity across all age groups, with patients ages 40 to 49 having the highest incidence in this large cross-sectional population, despite a high rate of early conversion to THA within 2 years in patients over 50. Level of Evidence IV, cross-sectional study.
Background
Total knee arthroplasty (TKA) and related interventions such as revision TKA and the treatment of infected TKAs are commonly performed procedures. Hospital readmission rates are used to ...measure hospital performance, but risk factors (both medical and surgical) for readmission after TKA, revision TKA, and treatment for the infected TKA have not been well characterized.
Questions/purposes
We measured (1) the unplanned hospital readmission rate in primary TKA and revision TKA, including antibiotic-spacer staged revision TKA to treat infection. We also evaluated (2) the medical and surgical causes of readmission and (3) risk factors associated with unplanned hospital readmission.
Methods
This retrospective cohort study included a total of 1408 patients (1032 primary TKAs, 262 revision TKAs, 113 revision of infected TKAs) from one institution. All hospital readmissions within 90 days of discharge were evaluated for timing and cause. Diagnoses at readmission were categorized as surgical or medical. Readmission risk was assessed using a Cox proportional hazards model that incorporated patient demographics and medical comorbidities.
Results
The unplanned readmission rate for the entire cohort was 4% at 30 days and 8% at 90 days. At 90 days postoperatively, revision of an infected TKA had the highest readmission rate, followed by revision TKA, with primary TKA having the lowest rate. Approximately three-fourths of readmissions were the result of surgical causes, mostly infection, arthrofibrosis, and cellulitis, whereas the remainder of readmissions were the result of medical causes. Procedure type (primary TKA versus revision TKA or staged treatment for infected TKA), hospital stay more than 5 days, discharge destination, and a fluid/electrolyte abnormality were each associated with risk of unplanned readmission.
Conclusions
Patients having revision TKA, whether for infection or other causes, are more likely to have an unplanned readmission to the hospital than are patients having primary TKA. When assessing hospital performance for TKA, it is important to distinguish among these surgical procedures.
Level of Evidence
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Abstract Background Degenerative hip disorders often coexist with degenerative changes of the lumbar spine. Limited data on this patient population suggests inferior functional improvement and pain ...relief after surgical management. The purpose of this study is to compare the rates of prosthetic-related complication following primary total hip arthroplasty (THA) in patients with and without prior lumbar spine arthrodesis (SA). Methods 811,601 Medicare patients undergoing primary THA were identified and grouped by length of prior SA (no fusion, 1-2 levels fused S-SAHA, ≥3 levels fused L-SAHA). Results Compared to controls, patients with prior SA had significantly higher rates of complications including dislocation (control:2.36%; S-SAHA:4.26%; L-SAHA:7.51%), revision (control:3.43%, S-SAHA:5.55%, L-SAHA:7.77%), loosening (control:1.33%, S-SAHA:2.10%, L-SAHA:3.04%) and any prosthetic-related complication (control:7.33%, S-SAHA:11.15% (RR 1.52), L-SAHA:14.16% (RR 1.93)) within 24 months (p<0.001). Conclusion The interplay of coexisting degenerative hip and spine disease deserves further attention of both arthroplasty and spine surgeons.
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