Younger age is associated with a higher risk of early periprosthetic joint infection and aseptic mechanical failure after total knee arthroplasty.

BACKGROUND: Although early aseptic mechanical failure after total knee arthroplasty has been reported in younger patients, it is unknown whether early revision due to periprosthetic joint infection is more or less frequent in this patient subgroup. The purpose of this study was to determine whether the incidence of early periprosthetic joint infection requiring revision knee surgery is significantly different in patients younger than fifty years of age compared with older patients following primary unilateral total knee arthroplasty. METHODS: A large population-based study was conducted with use of the California Patient Discharge Database, which allows serial linkage of all discharge data from nonfederal hospitals in the state over time. Patients undergoing primary unilateral total knee arthroplasty during 2005 to 2009 were identified. Principal outcomes were partial or complete revision arthroplasty due to periprosthetic joint infection or due to aseptic mechanical failure within one year. Multivariate analysis included risk adjustment for important demographic and clinical variables. The effect of hospital total knee arthroplasty volume on the outcomes of infection and mechanical failure was analyzed with use of hierarchical modeling. RESULTS: At one year, 983 (0.82%) of 120,538 primary total knee arthroplasties had undergone revision due to periprosthetic joint infection and 1385 (1.15%) had undergone revision due to aseptic mechanical failure. The cumulative incidence in patients younger than fifty years of age was 1.36% for revision due to periprosthetic joint infection and 3.49% for revision due to aseptic mechanical failure. In risk-adjusted models, the risk of periprosthetic joint infection was 1.8 times higher in patients younger than fifty years of age (odds ratio = 1.81, 95% confidence interval = 1.33 to 2.47) compared with patients sixty-five years of age or older, and the risk of aseptic mechanical failure was 4.7 times higher (odds ratio = 4.66, 95% confidence interval = 3.77 to 5.76). The rate of revision due to infection at hospitals in which a mean of more than 200 total knee arthroplasties were performed per year was lower than the expected (mean) value (p = 0.04). CONCLUSIONS: Patients younger than fifty years of age had a significantly higher risk of undergoing revision due to periprosthetic joint infection or to aseptic mechanical failure at one year after primary total knee arthroplasty.

Surgical treatment of trochanteric and cervical hip fractures in the United States: 2000-2009.

The objective of this study was to evaluate the most common treatments performed for hip fractures over the last decade in the United States. The leading treatment for trochanteric fractures was internal fixation, accounting for 96%-98% of surgical treatments each year. For cervical fractures, hemiarthroplasty (HA), total hip arthroplasty (THA), and internal fixation were performed nearly 61%, 5%, and 33% of the time, respectively, each year without any sign of change during the period assessed. The surgical choice for cervical fractures varied greatly by patient age. In 2009, two-thirds of patients younger than 60 years underwent internal fixation while two-thirds of patients 60 years or older underwent HA. Regardless of patient age, HA was performed more often than THA for cervical hip fractures.

Injection of the subacromial bursa in patients with rotator cuff syndrome: a prospective, randomized study comparing the effectiveness of different routes.

BACKGROUND: Rotator cuff syndrome is often treated with subacromial injection of corticosteroid and local anesthetic. It has not been established if the common injection routes of the bursa are equally accurate. METHODS: We conducted a prospective clinical trial involving seventy-five shoulders in seventy-five patients who were randomly assigned to receive a subacromial injection through an anterior, lateral, or posterior route with respect to the acromion. An experienced physician performed the injections, which contained radiopaque contrast medium, corticosteroid, and local anesthetic. After the injection, a musculoskeletal radiologist, blinded to the injection route, interpreted all of the radiographs. RESULTS: The rate of accuracy varied with the route of injection, with a rate of 56% for the posterior route, 84% for the anterior route, and 92% for the lateral route (p = 0.006; chi-square test). The accuracy of injection through the posterior route was significantly lower than that through either the anterior or the lateral route (p < 0.05 for both comparisons; Poisson regression). In addition, the accuracy of injection was significantly lower in females than in males (p < 0.006; chi-square test). Among males, no differences between the routes were noted (with accuracy rates of 89% for the posterior route, 92% for the anterior route, and 93% for the lateral route). Among females, however, the accuracy of injection was lower for the posterior route than for either the anterior or the lateral route (with accuracy rates of 38% for the posterior route, 77% for the anterior route, and 91% for the lateral route) (p < 0.05). CONCLUSIONS: The anterior and lateral routes of subacromial bursal injection were more accurate than the posterior route. The accuracy of subacromial bursal injection was significantly different between males and females, mainly because of a lower accuracy of bursal injection with use of the posterior route in females. The present study suggests that the posterior route is the least accurate method for injection of the subacromial bursa in females.

Epidemiology of primary hip and knee arthroplasties in Germany: 2004 to 2008.

The objective of this study was to describe the trend in utilization of primary joint arthroplasties in Germany. Between 2004 and 2008, the number of total knee arthroplasties (TKAs) increased faster than that of total hip arthroplasties (THAs). In 2008, 159000 primary THAs and 146000 primary TKAs were performed. This represented a 15% increase in THAs and a 33% increase in TKAs compared to 2004. The annual increase in number of surgeries was 4500 for THAs and 9,000 for TKAs. Although older adults remained the main recipients of joint arthroplasties, incidence rate increased faster in non-elderly(18-64 years) compared with elderly (≥65 years) in both THAs and TKAs. Obesity, more strongly associated with TKAs than with THAs, could be a contributor to the recent steeper growth in TKAs in Germany.

Incidence of carpal tunnel release: trends and implications within the United States ambulatory care setting.

PURPOSE: To investigate the changes, trends, and implications of carpal tunnel release (CTR) surgery within an ambulatory setting over the past decade in the United States. METHODS: We undertook an analysis of ambulatory surgery center CTR cases using data from the National Survey of Ambulatory Surgery. The Centers for Disease Control and Prevention carried out this survey in 1996, and again in 2006. We searched the cases with the procedure codes indicative of CTR. RESULTS: The number of CTR procedures increased by 38% (from 360,000 to 577,000) between 1996 and 2006. In 1996, 16% of all ambulatory CTRs were performed in freestanding ambulatory surgery centers (hospital-based centers were 84%), and the proportion increased to 49% in 2006. By 2006, greater than 99% of CTRs were performed in an ambulatory setting. There was a significant increase in women aged 50 to 59 years of age undergoing CTR. CONCLUSIONS: The minimal invasiveness of CTR combined with the advent of ambulatory care facilities has made CTR a predominantly outpatient procedure. In contrast to other reports, our study demonstrated a higher incidence of CTR within the United States in 2006 compared with 1996. Elderly women, in particular, with CTS were 3 times more likely to be treated surgically than other age groups. Further study is needed to better define factors influencing CTR indications. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Epidemiology of humerus fractures in the United States: nationwide emergency department sample, 2008.

OBJECTIVE: To evaluate the occurrence of emergency department (ED) visits due to humerus fractures in the US. METHODS: We analyzed the 2008 Nationwide Emergency Department Sample, which contained approximately 28 million ED records. We identified the cases of interest using diagnostic codes for proximal, shaft, and distal humerus fractures. RESULTS: In 2008, approximately 370,000 ED visits in the US resulted from humerus fractures. Proximal humerus fractures were the most common, accounting for 50% of humerus fractures. The incidence rate of proximal humerus fractures followed the shape of an exponential function in the age groups 40-84 years for women (R(2) = 97.9%) and 60-89 years for men (R(2) = 98.2%). After the exponential increase in these age intervals, the growth rate of proximal humerus fracture slowed and eventually decreased. The peak occurrence of distal humerus fractures was in children ages 5-9 years; however, elderly women had an increased risk. As the baby boomer generation ages, unless fracture prevention programs improve, more than 490,000 ED visits due to humerus fractures are expected in 2030 when the youngest of the baby boomers turn age 65 years. CONCLUSION: Compared to epidemiologic studies in Japan and European countries, the incidence rates of humerus fractures are substantially higher in the US. The high incidence rate of humerus fractures in the expanding elderly population may contribute to the recent trend of rapid increase in shoulder arthroplasty in the US. Rigorous safety measures to reduce falls and improved preventive treatments of osteoporosis are needed.

Hip fractures in the United States: 2008 nationwide emergency department sample.

OBJECTIVE: To evaluate the recent epidemiology of hip fractures in the US. METHODS: We identified hip fracture cases from the 2008 Nationwide Emergency Department Sample, which contains more than 28 million emergency department (ED) records. RESULTS: In 2008, approximately 341,000 (95% confidence interval 323,000-358,000) patients visited EDs with hip fractures. Of those, 90% were age >60 years. Between ages 60-85 years, the risk of fracture doubled for every 5- to 6-year increase in age. However, the hip fracture risk increased slowly after age 85 years. The overall trochanteric-to-cervical fracture ratio was nearly 2:1. The risk of trochanteric fracture increased faster with age compared with the risk of cervical fracture. At age 85 years, the rates of trochanteric and cervical fractures (per 100,000) were 1,300 and 700, respectively, among women and 800 and 500, respectively, among men. CONCLUSION: The slowed growth of hip fracture risk after age 85 years suggests that the eldest old group may have a distinct hip fracture risk. Our study showed that trochanteric fractures were twice as common as cervical fractures. Because trochanteric fractures are more closely related to severe and generalized bone loss than cervical fractures, we hypothesize that the high incidence rate of trochanteric fractures in the US suggests that osteoporosis is a health problem that is linked to hip fracture. In addition to improved safety measures to reduce falls, rigorous preventive treatments of osteoporosis may be needed.

Comparison of surgical outcomes and implant wear between ceramic-ceramic and ceramic-polyethylene articulations in total hip arthroplasty.

The results of a prospective multicenter trial comparing 357 hips randomized to total hip arthroplasty with either ceramic-ceramic or ceramic-polyethylene couplings are presented. No statistically significant difference in clinical outcomes scores between the ceramic-ceramic and ceramic-polyethylene groups was observed at any time interval. The mean linear rate was statistically lower (P < .001) in the ceramic-ceramic group (30.5 µm/year) when compared with the ceramic-polyethylene group (218.2 µm/year). The rates of ceramic implant fracture (2.6%) and audible component-related noise (3.1%) were statistically higher in the ceramic-ceramic group when compared with the ceramic-polyethylene group (P < .05). Lastly, there was no statistically significant difference in the dislocation or revision rate between the groups at the time of last clinical follow-up.

Intermediate-term radiographic and patient outcomes in revision hip arthroplasty with a modular calcar design and porous plasma coating.

This study is a retrospective evaluation of the intermediate-term results of 26 consecutive revision total hip arthroplasties performed with a modular titanium, uncemented femoral component. The average patient age at the time of revision total hip arthroplasty was 72 years, and there were an equal number of males and females. The mean follow-up was 5.7 years (ranging from 4 to 11 years). No re-revision was necessary during this follow-up time. The mean Harris hip score improved significantly (preoperative and postoperative score was 50.7 and 89.6, respectively; P < .001). Postoperatively, Short Form 36 functional scores averaged 67.7 across 9 functional parameters. Our observed low revision rate and favorable patient-reported outcome scores support the continuous use of modular titanium, uncemented femoral components in revision total hip arthroplasty.

Increasing incidence of shoulder arthroplasty in the United States.

BACKGROUND: The number of total shoulder arthroplasties performed in the United States increased slightly between 1990 and 2000. However, the incidence of shoulder arthroplasty in recent years has not been well described. The purpose of the present study was to examine recent trends in shoulder hemiarthroplasty and total shoulder arthroplasty along with the common reasons for these surgical procedures in the United States. METHODS: We modeled the incidence of shoulder arthroplasty from 1993 to 2008 with use of the Nationwide Inpatient Sample. On the basis of hemiarthroplasty and total shoulder arthroplasty cases that were identified with use of surgical procedure codes, we conducted a design-based analysis to calculate national estimates. RESULTS: While the annual number of hemiarthroplasties grew steadily, the number of total shoulder arthroplasties showed a discontinuous jump (p < 0.01) in 2004 and increased with a steeper linear slope (p < 0.01) since then. As a result, more total shoulder arthroplasties than hemiarthroplasties have been performed annually since 2006. Approximately 27,000 total shoulder arthroplasties and 20,000 hemiarthroplasties were performed in 2008. More than two-thirds of total shoulder arthroplasties were performed in adults with an age of sixty-five years or more. Osteoarthritis was the primary diagnosis for 43% of hemiarthroplasties and 77% of total shoulder arthroplasties in 2008, with fracture of the humerus as the next most common primary diagnosis leading to hemiarthroplasty. CONCLUSIONS: The number of shoulder arthroplasties, particularly total shoulder arthroplasties, is growing faster than ever. The use of reverse total arthroplasty, which was approved by the United States Food and Drug Administration in November 2003, may be part of the reason for the greater increase in the number of total shoulder arthroplasties. A long-term follow-up study is warranted to evaluate total shoulder arthroplasty in terms of patient outcomes, safety, and implant longevity.

Morbid obesity and excessive hospital resource consumption for unilateral primary hip and knee arthroplasty.

Two objectives of this study were (i) to estimate the number of primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) performed on morbidly obese people in the United States, and (ii) to estimate the economic impact of morbid obesity on hospital resource use. In 2006, approximately 2.9% (6713 cases) of primary THA and 4.2% (20,964 cases) of primary TKA recipients were diagnosed as morbidly obese. Despite the controversy associated with increased infection risk and failure rate, a large number of morbidly obese people seem to consider that the benefits outweigh the risks. When sex, age, race, and primary payer were held constant, the hospital resource consumption for unilateral primary THA and TKA was 9% ($1432) and 7% ($1025) higher among morbidly obese patients than among nonobese patients, respectively.

Medical visits among adults with symptoms commonly associated with an overactive bladder.

OBJECTIVES: To examine nationally representative data and thus obtain estimates of the use of healthcare providers associated with the overactive bladder (OAB) symptoms, a condition characterized by frequency, urgency and nocturia, with or with no urge incontinence, as although it is ranked among the 10 most common chronic medical conditions in the USA, the level of OAB-associated medical treatment remains largely unknown. METHODS: To estimate the number of annual OAB-associated medical visits among patients aged > or =18 years, three national databases in the USA (year 2000) were examined: the National Ambulatory Medical Care Survey, the National Hospital Ambulatory Medical Care Survey, and the National Hospital Discharge Survey. Population estimates were constructed using design-based statistical analyses to account for the complex survey designs of data. RESULTS: During 2000, adult Americans made 1.4 million (95% confidence interval 1.1-1.8 million) ambulatory visits to non-Federal office-based physicians with International Classification of Disease (ICD-9) coding indicative of OAB symptoms. Accounting for emergency and outpatient department visits, as well as non-Federal short-stay hospital discharges, the estimated number of medical visits with OAB-associated ICD-9 coding was <1.5 million. CONCLUSION: The prevalence of OAB was estimated to be 34 million adult Americans. When 1.4 million ambulatory visits were compared with this prevalence, as few as 4% of adult Americans with OAB sought medical treatment during the year 2000. The present results therefore suggest a large unmet medical need among the population of adult Americans with OAB.