Rates of total hip arthroplasty; a population-based study

Referral Bias in Primary Total Knee Arthroplasty: Retrospective Analysis of 22,614 Surgeries in a Tertiary Referral Center

BACKGROUND

Patients who travel a significant distance to obtain surgical treatment typically experience better outcomes. This is called the referral bias and can limit the generalizability of studies performed at large tertiary care centers. We explored the influence of referral bias by comparing the clinical characteristics and outcomes of total knee arthroplasty (TKA) at a large tertiary care hospital in the United States.

METHODS

The study cohort included 22,614 primary TKA procedures performed between 1985 and 2010. Patients were stratified into 5 groups using home address zip codes and according to travel distance from the hospital. Clinical characteristics and the risk of TKA complications and surgical outcomes (instability, surgical-site infections, and thrombovascular complications within the first year, reoperations, revisions, and mortality) were compared across the 5 groups.

RESULTS

Compared with local patients, patients who traveled from other parts of the United States were significantly younger (mean age 67.8 vs 68.5 years; P < .05), were more likely to be male (47% vs 38%, P < .001), had lower body mass index (mean 30.4 vs 31.8 kg/m²; P < .001), were more likely to have inflammatory arthritis or neoplasms as surgical indications (P < .05), and were more likely to have a history of prior surgeries on the same knee (20% vs 14%; P < .001). Referral patients also had significantly higher American Society of Anesthesiologists scores and longer operative times (mean 173 vs 156 minutes P < .001). Despite these differences, the risk of instability, surgical-site infections, thrombovascular complications, reoperations, and revision surgeries were similar across the 5 groups.

CONCLUSION

Although referral patients differ from local patients, the groups seem to experience largely similar complication and revision rates after TKA.

Epidemiology of hip replacements in Korea from 2007 to 2011

We analyzed national data collected by the Health Insurance Review and Assessment Service in Korea from 2007 to 2011; 1) to document procedural numbers and procedural rate of bipolar hemiarthroplasty (BH), primary and revision total hip arthroplasties (THAs), 2) to stratify the prevalence of each procedure by age, gender, and hospital type, and quantified, 3) to estimate the revision burden and evaluate whether the burden is changed over time. Our final study population included 60,230 BHs, 40,760 primary THAs, and 10,341 revision THAs. From 2007 to 2011, both the number and the rate of BHs, primary THAs increased steadily, whereas there was no significant change in revision THAs. Over the 5 yr, the rate of BHs and primary THAs per 100,000 persons significantly increased by 33.2% and 21.4%, respectively. The number of revision THAs was consistent over time. The overall annual revision burden for THA decreased from 22.1% in 2007 to 18.9% in 2011. In contrast to western data, there were no changes in the number and rate of revision THAs, and the rates of primary and revision THAs were higher for men than those for women. Although 5 yr is a short time to determine a change in the revision burden, there have been significant decreases in some age groups.

Spatial-temporal gait characteristics in individuals with hip osteoarthritis: a systematic literature review and meta-analysis

STUDY DESIGN

Systematic literature review and meta-analysis.

OBJECTIVE

To systematically review and critically evaluate the literature to determine how basic gait characteristics are altered in individuals with hip osteoarthritis (OA).

BACKGROUND

Hip OA is a progressive musculoskeletal condition that leads to pain, stiffness, and functional limitation in activities such as walking. Understanding gait dysfunction in people with hip OA may contribute to more effective management of the disease.

METHODS

Eleven electronic research databases were searched. Studies comparing basic gait parameters in individuals with hip OA to healthy controls and the affected to the contralateral limb of individuals with hip OA were included. The studies were critically appraised for methodological quality. Available data were extracted, and meta-analysis was performed, with standardized effect sizes (Cohen d) and corresponding 95% confidence intervals computed for gait speed, cadence, step and stride length, stance, swing and double-stance duration, and step width.

RESULTS

The final analysis included 30 articles. Self-selected gait speed was 26% slower in individuals with hip OA relative to controls, which was explained by shorter stride length. Consistent evidence was found for greater asymmetry in individuals with hip OA than controls, with shorter step length and stance duration in the affected compared to the contralateral limb.

CONCLUSION

Individuals with hip OA walk at a slower speed and exhibit greater gait asymmetry than controls. Gait speed and asymmetry can be readily assessed clinically and represent a simple way of objectively evaluating gait dysfunction and monitoring treatment progress in individuals with hip OA.

Epidemiology of knee and hip arthroplasty: a systematic review

We present a systematic review of epidemiologic studies of Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA). The studies summarized in this systematic review provide us with estimates of arthroplasty utilization rates, underlying disease frequency and its trends and differences in utilization rates by age, gender and ethnicity among other factors. Among these, many studies are registry-based that assessed utilization rates using data from major orthopedic centers that may provide some understanding of underlying diagnosis and possibly time-trends. Several studies are population-based cross-sectional, which provide estimates of prevalence of TKA and THA. Population-based cohort studies included in this review provide the best estimates of incidence and utilization rates, time-trends and differences in these rates by important patient characteristics (age, gender, ethnicity and others). This article reviews the current published literature in the area and highlights the main findings.

Arthroscopy and the dramatic increase in frequency of anterior acromioplasty from 1980 to 2005: an epidemiologic study

PURPOSE

The purposes of this study was to better understand the utilization of anterior acromioplasty over time, in the absence of rotator cuff repair; to examine the relation to patient characteristics (age, sex) and types of rotator cuff pathology (inflammation or fibrosis, partial-thickness tearing, full-thickness tearing undergoing debridement); and to assess the utilization of arthroscopy in this procedure.

METHODS

Using the resources of the Rochester Epidemiology Project, cataloging medical records of residents in Olmsted County, Minnesota, we identified 246 patients who underwent anterior acromioplasty between 1980 and 2005. It has previously been shown that rarely does a resident of Olmsted County undergo an orthopaedic procedure at a facility outside the county.

RESULTS

The incidence of anterior acromioplasty increased over time (P < .001), with crude rates of 3.3 per 100,000 persons in 1980 to 1985 and 19.0 per 100,000 persons in 2000 to 2005. Sex, age, and types of rotator cuff pathology did not significantly change over the 26-year period. There was a dramatic shift from use of the open approach to the arthroscopic approach over this time period (P < .001) and a decrease in the concomitant performance of distal clavicle resection (P < .001).

CONCLUSIONS

The frequency of anterior acromioplasty has dramatically increased over time. Increasing knowledge about this syndrome, including better imaging, has facilitated patient treatment for a stable spectrum of rotator cuff pathology (inflammation or fibrosis, partial-thickness tearing, full-thickness tearing undergoing debridement), as has the application of endoscopic surgery.

LEVEL OF EVIDENCE

Level III, epidemiologic study.

Are Critical Pathways and Implant Standardization Programs Effective in Reducing Costs in Total Knee Replacement Operations?

BACKGROUND

Total knee replacement (TKR) operation is one of the most effective procedures, both clinically and in terms of cost. Because of increased volume and cost for this procedure during the past 3 decades, TKRs are often targeted for cost reduction. The purpose of this study was to evaluate the efficacy of two cost reducing methodologies, establishment of critical clinical pathways, and standardization of implant costs.

STUDY DESIGN

Ninety patients (90 knees) were randomly selected from a population undergoing primary TKR during a 2-year period at a tertiary teaching hospital. Patients were assigned to three groups that corresponded to different strategies implemented during the evolution of the joint-replacement program. Medical records were reviewed for type of anesthesia, operative time, length of stay, and any perioperative complications. Financial information for each patient was compared among the three groups.

RESULTS

Data analysis demonstrated that the institution of a critical pathway significantly shortened length of hospital stay and was effective in reducing the hospital costs by 18% (p < 0.05). In addition, standardization of surgical techniques under the care of a single surgeon substantially reduced the operative time. Selection of implants from a single vendor did not have any substantial effect in additionally reducing the costs.

CONCLUSIONS

Standardized postoperative management protocols and critical clinical pathways can reduce costs and operative time. Future efforts must focus on lowering the costs of the prostheses, particularly with competitive bidding or capitation of prostheses costs. Although a single-vendor approach was not effective in this study, it is possible that a cost reduction could have been realized if more TKRs were performed, because the pricing contract was based on projected volume of TKRs to be done by the hospital.

Outcomes of shoulder arthroplasty in Olmsted County, Minnesota: a population-based study

Most studies on shoulder arthroplasty include a diverse group of patients presenting to a tertiary care center. Little information is available regarding outcomes in a community setting. We reviewed 98 residents (110 shoulders) of Olmsted County, Minnesota who had shoulder arthroplasties from 1976 to 2000. There were 65 total shoulder arthroplasties and 45 humeral head replacements. The most common indications were osteoarthritis for total shoulder arthroplasties (48/65) and acute fracture for hemiarthroplasties (27/45). The Neer ratings were excellent or satisfactory in 92% of total shoulder arthroplasties and 56% of hemiarthroplasties. The 10-year survival rate was 96%. The mean postoperative active forward elevation was greater in patients who had a total shoulder arthroplasty (132 degrees) compared with a hemiarthroplasty (113 degrees), as was external rotation (total shoulder arthroplasties = 58 degrees, humeral head replacements = 38 degrees). The outcomes for total shoulder arthroplasty and hemiarthroplasty compared favorably with outcomes reported in the literature. There was a high rate of satisfactory or excellent results after total shoulder arthroplasty for osteoarthritis. Hemiarthroplasty offered less satisfactory results, most likely related to the use of this procedure for trauma. This information will assist the community surgeon in counseling patients and weighing the risks and benefits of a shoulder arthroplasty.

Prothèse totale de hanche bilatérale en une session opératoire

PURPOSE OF THE STUDY

We conducted a prospective study of patients undergoing simultaneous bilateral total hip arthroplasty (THA) in order to assess perioperative complications. A review of the literature revealed the pertinence of surgical management of patients with invalidating bilateral degenerative hip disease using a single-stage procedure.

MATERIAL AND METHODS

Ten patients, four females and six males, mean age 57.8 years (range 33-71 year) were included in the study. The ASA classification was 1 for nine patients and 2 for one. The procedure was performed in the lateral reclining position using a posterolateral approach. Mean operative time was 212 minutes (range 165-270min) and mean blood loss as assessed by serum hemoglobin level was 9 mmol/l preoperatively and 5.93 mmol/l postoperatively. Three patients required transfusion. Mean hospital stay was 11 days (range 7-13 d). Leg length discrepancy improved from an average 4 mm preoperatively to 0.5 mm postoperatively.

RESULTS

One patient developed a sacral pressure sore which resolved in 21 days. One patient developed a wound infection (Pseudomonas aeruginosa) which resolved with local treatment. No other complication (death, pulmonary embolism, dislocation, deep infection, stiffness, heterotopic ossification) was observed 17.6 at 15 months of follow-up. There were no revision procedures. The Postel-Merle-d'Aubigné score improved from 9.6 preoperatively to 15 at mean follow-up (range 10-24 months).

DISCUSSION

Bilateral implantation of THAs in a single-stage procedure is indicated for chronic invalidating bilateral degenerative disease. About 0.5% to 3% of hip replacement procedures concern simultaneous bilateral implantations. The complication rate is no higher than after sequential surgery or even after single THA procedures, including the risk of pulmonary embolism. The cost of the procedure and the mean hospital stay are reduced compared with two operations. Rehabilitation is facilitated. The operative time is however longer and the risk of bleeding is increased but can be compensated for preoperatively and minimized intra- and postoperatively. This attractive strategy is not currently sufficiently reimbursed by the current conditions of the French health care insurance system.

Brief report: Gender and total knee/hip arthroplasty utilization rate in the VA system

OBJECTIVE

Osteoarthritis (OA) is a leading cause of disability and is more prevalent in women than men. Total joint arthroplasty is an effective treatment option for end-stage OA. We examined gender differences in utilization rates of total knee/hip arthroplasty in the Veterans Administration (VA) system.

METHODS

The sample consisted of all VA patients for fiscal year (FY) 1999, 50 years of age or older, with or without the diagnosis of OA in any joint. We calculated the odds of patients undergoing total knee/hip arthroplasty adjusting for age, comorbidities, and presence of OA. We included the hospital site as a random effects variable to adjust for clustering.

RESULTS

Of the 1,968,093 (2.3% women) VA patients in FY 1999 who were 50 years of age or older, 329,461 (2.9% women) patients carried a diagnosis of OA. For women, 2-year adjusted odds of undergoing total knee or hip arthroplasty were 0.97 (0.83 to 1.14) and 1.00 (0.79 to 1.27), respectively.

CONCLUSION

Among patients potentially at risk for the procedure, men and women in the VA system were equally likely to undergo knee/hip arthroplasty.

Shoulder arthroplasty in Olmsted County, Minnesota, 1976-2000: a population-based study

Because little information is currently available on the epidemiology of shoulder arthroplasty, this study was designed to evaluate the characteristics of patients undergoing this procedure and changes in practice patterns. Residents of Olmsted County, Minnesota, who underwent shoulder arthroplasty between 1976 and 2000 were identified (98 residents, 112 procedures). A relatively lower initial rate of shoulder arthroplasty was followed by a statistically significant steady increase (P < .0001), with an age- and sex-adjusted annual operative incidence rate of 1.4 per 100,000 person-years (1976-1980) to 10.1 per 100,000 person-years (1996-2000). Increased utilization of shoulder arthroplasty during the last decade was mainly a result of its application in osteoarthritis. A significant need exists for examination of utilization patterns for shoulder arthroplasty. An aging population and an increased demand and awareness by the public regarding interventions to improve quality of life will shape the future of arthroplasty, reinforcing the need for future studies of this nature.

Access to health care resources in the UK: the case of care for arthritis

The paper uses new and detailed data from a population sample of individuals with arthritis to examine the impact of objective measures of need for treatment and individual measures of socio-economic position on the distribution of public and private health care. The quality of the data and the range of explanatory factors are more detailed than previously used to study of the allocation of NHS care. The results indicate that broadly the NHS appears to meet its equity goal of equal care for equal medical need, though there is evidence that education increases the amount of resources received. The results also show the importance of the interaction between the public and private sectors in the UK.

The impact of medicare reimbursement policies on simultaneous bilateral total hip and knee arthroplasty

In October of 1992, Medicare reimbursement decreased by 50% for a second total hip or knee arthroplasty performed as part of a simultaneous bilateral procedure. The Medicare records of 67726 patients who underwent total hip and knee arthroplasty were reviewed using data from the New York State Department of Health in the period from October 1, 1989, to September 30, 1996. Simultaneous bilateral total hip arthroplasties represented 1.8% of the total number of total hip replacements performed in fiscal year 1991 (60 of 3418) compared with 1.7% (77 of 4547) performed in fiscal year 1994 (P=.902). Similarly, the number of simultaneous bilateral total knee arthroplasties did not change significantly, with simultaneous bilateral procedures representing 5.9% of the total number of total knee replacements performed in fiscal year 1991 (214 of 3620) compared with 6.2% (369 of 5,931) performed in fiscal year 1994 (P=.568).

Total hip and knee replacement surgeries in Alberta utilization and associated outcomes

OBJECTIVE

Between 1994/95 and 1996/7, the healthcare system in Alberta underwent a radical transformation that saw the regionalization of service delivery and a reduction in overall healthcare funding. The aim of this study is to examine trends in utilization and associated post-operative complications and readmissions for two procedures, total hip arthroplasty (THA) and total knee arthroplasty (TKA) during this period of restructuring.

METHODS

This is a six-year retrospective analysis using hospital separation and healthcare insurance plan registry databases. During the study period, we looked at trends in inpatient procedure volumes, average lengths of stay, post-operative complications during the index hospital stay and readmissions within one year.

RESULTS

Over a six-year period, the age-sex standardized provincial rate of THAs increased by 18% while the rate of TKAs increased by 73%. Average lengths of stay decreased for both procedures by over 50%. The rate of procedures with at least one post-operative complication within the index episode of care decreased over the study period by 19% for THA and 21% for TKA. Readmissions due to complications of surgery increased overall by 32% for THA and 2% for TKA. Regional and sex differences were observed throughout the period.

CONCLUSIONS

While the overall rate of hospitalizations has decreased in Alberta, the rates of THA and TKA procedures have increased. The lengths of stay following these procedures have, at the same time, reduced dramatically. Adverse outcomes as measured by complication rates associated with these procedures have decreased, though readmissions due to complications after surgery have increased.

Incidence of total hip replacement for primary osteoarthrosis in Iceland 1982-1996

We report the incidence of total hip replacements performed in Iceland between 1982 and 1996. During this period, 3,403 hip arthroplasties were done. The annual number of procedures increased from 94 hips in 1982 to 323 hips in 1996. Annual rates of total hip replacements due to primary osteoarthrosis per 10(5) inhabitants were 68 in 1982-1986, 90 in 1987-1991, and 114 in 1992-1996. In the years 1992-1996, the age-standardized incidence of total hip replacements for primary osteoarthrosis was 3/10(5) among patients younger than 39 years of age, while it was 621/10(5) among those 70-79 years of age. The mean age at surgery for primary osteoarthrosis was 69 years in both men and women. Incidence rates in various countries are difficult to compare, but by using age-standardized data and correction for differences in population structures between Iceland and Sweden, we find that the incidence of total hip replacement for primary osteoarthrosis of the hip is at least 50% higher in Iceland than in Sweden. This difference is consistent with the higher prevalence of hip osteoarthrosis observed in Iceland than in Sweden.

Population requirement for primary hip-replacement surgery: a cross-sectional study

BACKGROUND

There has been a long-standing failure in many countries to satisfy the demand for several elective surgical treatments, including total hip replacement. We set out to estimate the population requirement for primary total hip replacement in England.

METHODS

We undertook a cross-sectional study of a stratified random sample of 28,080 individuals aged 35 and over from 40 general practices in inner-city, urban, and rural areas of Avon and Somerset, UK. Prevalent disease was identified through a two-stage process: a self-report screening questionnaire (22,978 of 26,046 responded) and subsequent clinical examination. Incident disease was estimated from the point prevalence by statistical modelling. The requirement for total hip replacement surgery was estimated on the basis of pain and loss of functional ability, with adjustment for evidence of comorbidity and patients' treatment preferences.

FINDINGS

3169 people reported hip pain on the screening questionnaire. 2018 were invited for clinical examination, and 1405 attended. The prevalence of self-reported hip pain was 107 per 1000 (95% CI 101-113) for men and 173 per 1000 (166-180) for women. The prevalence of hip disease severe enough to require surgery was 15.2 (12.7-17.8) per 1000 aged 35-85 years. The corresponding annual incidence of hip disease requiring surgery was estimated as 2.23 (1.56-2.90), which suggests an overall requirement in England of 46,600 operations per year for patients who expressed a preference for, and were suitable for, surgery; the recent actual provision in England was about 43,500.

INTERPRETATION

This research suggests that the satisfaction of demand for total hip replacement, given agreed criteria for surgery, is a realistic objective.

A comparison of the cost effectiveness of one-stage versus two-stage bilateral total hip replacement

Forty patients underwent 80 bilateral primary total hip replacements (THRs) under the same anesthesia (one-stage). Forty other patients who underwent unilateral primary THRs during the same time interval were selected to match the first 40 patients with regard to age, sex, diagnosis, weight, medical comorbidity, type of prosthesis used, and perioperative management protocol. An assumption was made in that each unilateral case represented the first side of bilateral THRs performed during two separate hospitalizations (two-stage). Analysis of the total hospital charges submitted to the insurance companies was made between the groups. On average, there was a 24% reduction (P<.05) for each case if bilateral THRs were done in one stage. This was primarily due to a significant decrease (P<.05) in the length of hospital stay in the one-stage group. There was no difference between the two groups in the operative time, estimated blood loss, or perioperative complications.

Total hip replacement rates are higher among Caucasians than Asians in Hawaii

The etiology of hip osteoarthritis remains unknown but may involve genetic or lifestyle factors. Most cases of total hip replacement are performed because of osteoarthritis. To examine possible ethnic differences, hospital records in Hawaii from 1985 to 1989 were reviewed. Preoperative radiographs were reviewed for a subset of patients to ascertain the reason for total hip replacement. Osteoarthritis accounted for a greater percentage of total hip replacements among whites (59% for women and 66% for men) than among Japanese (36% of women and 30% of men). The incidence of total hip replacement for whites was three to 25 times greater than that of other ethnic groups (Japanese, Chinese, Filipino, and Hawaiians). For example, the risk of total hip replacement for white women 40 years to 84 years of age was 4.4%, compared with 1.1% for Japanese women and 1.7% for Chinese women of the same age group. Compared with published data, the incidence was similar for Chinese in Hawaii and San Francisco; however; whites in Hawaii had a total hip replacement incidence less than half that of whites in San Francisco. Lifestyle differences might account for the lower incidence of total hip replacement for whites in Hawaii, compared with those in San Francisco. The lower incidence among Asians suggests a possible genetic basis for osteoarthritis.

Total hip arthroplasty: use and select complications in the US Medicare population

Use and outcomes of primary total hip arthroplasty among US Medicare recipients more than 65 years of age were investigated by means of physician and hospital claims for a 5% random sample during 1986 through 1989. Cases involving hip fracture or evidence of existing orthopedic devices in the hip were omitted. Use rates were higher for women than for men and were substantially lower for Blacks than Whites. Major complications (death, further hip surgery, infection pulmonary embolism) were uncommon. These data document the frequent use of total hip arthroplasty, and confirm the rarity of serious adverse outcomes. Further studies should investigate the lower use of total hip arthroplasty among Blacks.

Lack of evidence for gender bias in the utilization of total hip arthroplasty among Olmsted County, Minnesota residents with osteoarthritis

OBJECTIVE

To evaluate whether women have more advanced osteoarthritis (OA) than men prior to total hip arthroplasty (THA).

METHODS

Preoperative clinical and radiographic severity of hip OA was determined among Olmsted County, Minnesota residents who underwent THA. The time from first radiographic changes and first symptoms to THA was compared between genders.

RESULTS

Fifty men and 80 women underwent their first THA between 1985 and 1990. Men had higher disease activity levels preoperatively; however, 16 other clinical severity variables and 2 summary measures of OA severity were similar for both genders. Men had radiographically more advanced hip OA preoperatively. The time from first symptom of hip OA to THA was similar for both genders, while the time from first radiographic change to THA was significantly longer for men.

CONCLUSION

These results fail to support the hypothesis that hip OA prior to THA is more severe among women compared with men.

Differences between men and women undergoing major orthopedic surgery for degenerative arthritis

OBJECTIVE

To determine whether women have worse functional status than men at the time of laminectomy for degenerative spinal stenosis or total joint arthroplasty for degenerative arthritis of the hip and knee.

METHODS

Consecutive patients undergoing laminectomy for degenerative lumbar spinal stenosis or unilateral, primary hip or knee arthroplasty for advanced degenerative arthritis were recruited. Functional status was measured with self-administered questionnaires. We compared preoperative functional status scores of men and women, using linear regression models that adjusted for age, comorbid conditions, work status, education, living arrangement, and body mass index. We also compared the rates of in-hospital complications and 6-month followup functional status scores for men and women.

RESULTS

Women had much worse functional status than men prior to laminectomy for spinal stenosis (P < 0.01) and prior to total hip arthroplasty (P < 0.001) and total knee arthroplasty (P < 0.0001). These differences persisted after statistical adjustment for demographic and clinical characteristics. Women had comparable or greater functional improvement following surgery and experienced a similar number of complications compared with men.

CONCLUSIONS

The observed gender differences in functional status prior to major orthopedic surgery indicate that women are operated on at a more advanced stage in the course of their disease. These results are not due to gender differences in demographic or clinical characteristics of the patients, and cannot be justified by differences between men and women in the outcome of surgery. The role of patient preferences and differential access to these procedures should be explored in future studies.

Sterilisation of implantable devices

The pathogenesis and rates of infection associated with the use of a wide variety of implantable devices are described. The multi-factorial nature of post-operative periprosthetic infection is outlined and the role of sterilisation of devices is explained. The resistance of bacterial spores is highlighted as a problem and a full description is given of the processes of sterilisation by heat, steam, ethylene oxide, low temperature steam and formaldehyde, ionising radiation and liquid glutaraldehyde. Sterility assurance and validation are discussed in the context of biological indicators and physical/chemical indicators. Adverse effects upon the material composition of devices and problems of process control are listed. Finally, possible optimisations of the ethylene oxide process and their potential significance to the field of sterilisation of implants is explored.

Urban vs rural increase in hip fracture incidence. Age and sex of 901 cases 1980-89 in Olmsted County, U.S.A

To determine if hip fracture incidence rates are greater in urban than in rural areas of the United States, as they appear to be in Scandinavia, we undertook a study in Olmsted County, Minnesota. During the decade 1980-89, the age- and sex-adjusted incidence of proximal femur fractures among urban residents of the central city of Rochester was 36 percent greater than among residents of the rural remainder of Olmsted County. The difference was almost entirely accounted for by an excess of fractures due to moderate trauma in elderly urban women. These first detailed results from the United States confirm earlier observations from Scandinavia that hip fracture rates are lower in rural areas.

Trends in the utilization of primary total hip arthroplasty, 1969 through 1990: a population-based study in Olmsted County, Minnesota

Using the unique data resources of the Rochester Epidemiology Project, we identified the residents of Olmsted County, Minnesota, who underwent total hip arthroplasty (THA) between 1969, when this technique was introduced, and 1990. During this period, 735 residents underwent 859 primary THAs. An initial dramatic upsurge in utilization of THA soon after its introduction was followed by a lower rate of increase, to an age- and sex-adjusted rate of 59.9 per 100,000 person-years in 1987 through 1990. In Olmsted County, the procedure was used more often in women than in men, but men underwent THA at a younger age than did women. THAs were performed for various conditions of the hip, but the increased utilization during the last decade of the study was mainly attributable to its application in primary degenerative hip disease among patients (male more often than female) from a wider age range; utilization of THA for hip fractures decreased during the study period. Most THAs were of the cemented variety (86.1%); however, the rate of use of noncemented THAs, first performed in 1984, is increasing. The overall upward trend in Olmsted County was consistent with European data but less than the rate of increase observed for the United States as a whole between 1983 and 1987. Olmsted County utilization rates, if projected nationally, suggest a need for more than 139,000 primary THAs each year at an annual direct cost of more than $2.7 billion. An urgent need exists for detailed examination of national utilization patterns and clarification of the role of cementless implants and of THA for hip fractures.

Hip arthroplasty in Jutland, Denmark. Age and sex-specific incidences of primary operations

During the 10-year period 1981-90, 1752 primary total hip arthroplasties were performed in the County of South Jutland, Denmark. The annual number increased to a steady state during 1988-90. In this period, the incidence was highest in the age group 70-79 years for both women and men, with 485 and 410 arthroplasties per 100,000 inhabitants, respectively; the overall incidence was 82 per 100,000 inhabitants. During the next 30 years, the demand for primary hip arthroplasties in Denmark is expected to increase because of demographic changes.

Total knee arthroplasty: a population-based study

Total knee arthroplasty (TKA) is being used increasingly for the management of chronic arthritis of the knee. In this report, we review the frequency of application of TKA in the population of Olmsted County, Minnesota, from 1971 through 1986. The utilization rate of TKA increased from 20.5 per 100,000 person-years for 1971 through 1974 to 60.8 per 100,000 for 1983 through 1986. Although rates were higher in women, they increased with advancing age in both sexes. Rates between the urban and rural populations of Olmsted County did not differ. The two most common underlying diseases that necessitated TKA were osteoarthritis and rheumatoid arthritis; they were the cause of more than 90% of all operations. By extrapolating the rates of TKA in Olmsted County to the total 1986 US population, we estimate a need for at least 143,000 TKAs annually at a direct cost of more than $2.3 billion each year.

Idiopathic symptomatic osteoarthritis of the hip and knee: a population-based incidence study

We identified all residents of Rochester, Minnesota, who sought medical assistance for the first time in 1985 because of symptomatic osteoarthritis of the hip or knee that was unrelated to a specific disease. Of these residents, 98 (59 women and 39 men) had 122 symptomatic joints (95 knees and 27 hips), for age- and sex-adjusted incidence rates of 205 new patients and 255 newly affected joints per 100,000 person-years. The incidence of osteoarthritis of the hip was greater in women than in men, whereas the sex ratio for occurrence of osteoarthritis of the knee approached unity. Rates at both sites increased steadily with aging in men but plateaued after the menopause in women; similar patterns were seen whether or not grade 1 disease was included. Projected nationally, these first population-based data indicate that as many as approximately half a million new symptomatic cases of idiopathic osteoarthritis of the knee and hip may arise annually in the white population of the United States. With increasing longevity, osteoarthritis may exact an even greater toll in the future.

Appropriateness of acute medical care for the elderly: an analysis of the literature

Over the past 30 years, an explosion in health care expenditures has occurred. Prior to 1960, health care accounted for 4.4% of the U.S. Gross National Product; today it is 11%. Before rational solutions to controlling this rise can be proposed, we must determine whether the care that we are currently paying for is appropriate to the needs of the elderly. This paper analyzes the literature regarding appropriateness of acute care provided to the elderly. We identified 17 articles that explicitly cited appropriate or inappropriate care (including under-, over- and misuse) provided in hospital and ambulatory settings and for procedures, and 19 articles that presented data on the appropriateness of medication use in the elderly. Virtually every study included in this review found at least double-digit levels of inappropriate care. Perhaps as much as one-fifth to one-quarter of acute hospital services or procedures were felt to be used for equivocal or inappropriate reasons, and two-fifths to one-half of the medications studied were overused in outpatients. The few studies that examined underuse or misuse of services also documented the existence of these phenomena. This was especially true for the ambulatory care of chronic physical and mental conditions and concerned the use of low-cost technologies (visits, preventive services, some medications). Thus, we conclude that there appears to be a substantial problem in the matching of acute services to the needs of elderly patients. This mismatch occurs both in terms of overuse and underuse, at least for areas where research has been conducted.

Medical problems in joint replacement patients: a retrospective study of 243 total hip arthroplasties

Two hundred and forty-three total hip arthroplasties were performed in 217 patients over a five-year period in one institution. Seventy-one per cent had one or more significant preoperative medical problems, 22% being referred for preoperative management to a specialist physician. Thirty per cent of patients experienced re-activity of medical problems after operation; in 41% of patients a physician review was sought while in a further 40% the problems were apparently unnoticed or not acted upon. There was a positive correlation between preoperative and postoperative medical problems (P less than 0.001). Fifteen per cent of patients developed complications and one patient died. There was a highly significant trend towards longer hospital stay in patients with medical problems and complications (P less than 0.001). It is concluded that there is a high incidence of medical problems in joint replacement patients, that these problems have an influence on the morbidity and cost of the procedure, and that management of these problems can be improved.

Infections associated with indwelling devices: concepts of pathogenesis; infections associated with intravascular devices

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Anaesthesia for hip surgery in the elderly

Surgical repair of hip fracture and total hip arthroplasty are primarily performed on elderly patients. Patients presenting for hip fracture surgery have a high prevalence of preoperative medical problems and may require medical stabilization before surgery. Regional anaesthesia for hip fracture repair may be contraindicated due to perioperative pharmacologic prophylaxis for deep venous thrombosis. The use of regional anaesthesia increases the magnitude and frequency of hypotensive episodes when compared with general anaesthesia. Intraoperative blood losses, averaging 250-300 ml, are not affected by anaesthetic technique. Following hip fracture surgery under spinal anaesthesia, patients exhibit better oxygenation in the early postoperative period than those after general anaesthesia. The frequency of postoperative confusion is unrelated to anaesthetic technique. The incidence of deep venous thrombosis is reduced following spinal anaesthesia as compared with general anaesthesia. The one-month mortality rate, approximately eight per cent, is unrelated to anaesthetic technique. Spinal, epidural and general anaesthesia have been used successfully for total hip arthroplasty. Intraoperative blood loss of 0.5-1.5 litres is reduced with regional anaesthesia. General anaesthesia with controlled hypotension also significantly reduces blood loss. Intraoperative instability with hypoxaemia, hypotension and cardiac arrest may follow impaction of the femoral prosthesis and are related to absorption of acrylic cement monomers and pulmonary embolism of fat, air, and platelet-fibrin aggregates. Postoperative deep venous thrombosis is common and the incidence may be reduced with epidural anaesthesia. Operative mortality is less than one per cent and pulmonary embolism is the commonest cause of death.(ABSTRACT TRUNCATED AT 250 WORDS)

Secular trends in the incidence of hip fractures

To explore possible changes in proximal femur (hip) fracture incidence over time, an earlier study among Rochester, Minnesota residents for 1928-1977 was updated through 1982. Reanalysis of data demonstrated rising age-adjusted rates for men over this time. Crude rates rose for women as well, but age adjusted rates leveled off in the mid-1950s, as did overall rates, since the majority of hip fractures were in women. Secular trends were primarily due to changes in the incidence of initial hip fractures associated with moderate trauma, the sort usually attributed to osteoporosis. No differences were noted in trends for cervical vs. intertrochanteric femur fractures; and, excluding the low values for 1928-1942, no significant trends were noted for women within various age groups. Our results for women conflict with estimates from a number of other studies, but these differences may provide a basis for hypothesis development.

Incidence of hip replacement in southern Sweden

During the years 1981-1982, 1,729 hip replacements were performed in the population of 943,000 persons in the nine southernmost orthopedic districts of Sweden. This is equivalent to 7,600 hip replacements per annum in the 8.3 million Swedish population. Based on the highest annual district incidence, the national equivalent increases to 12,500. Arthrosis accounted for 57 per cent of the arthroplasties, hip fracture for 23 per cent, and failed total hip replacement for 10 per cent.

Social and health policy issues in total joint replacement surgery

Total joint replacement has restored function and provided comfort to many patients who would otherwise have suffered. However, success and widespread diffusion of this procedure pose a number of important questions. The patient's and the doctor's criteria of success may not be the same: Which are to be used? Health resources are becoming limited: Should money be spent to restore function and for pain relief to those late in life or past their work life? Who makes this choice? A medical technology is tested in the best of settings but routinely practiced in many: How should society and health care professionals monitor the results of surgery? Who should do surgery and where should it be done?

Use of gastroscopy in a community: a population-based study in Olmsted County, Minnesota

We determined the use of gastroscopy in a defined population (Olmsted County, Minnesota) during the 3-year period 1978 through 1980. In slightly more than 271,000 person-years of observation, 418 residents underwent gastroscopy on 487 separate occasions. When age- and sex-adjusted to the structure of the US white population in 1980, the utilization rate was 215.9 per 100,000 person-years. With extrapolation of these data, approximately 500,000 gastroscopies would be expected to be performed in the United States each year.

Cost-effectiveness of total joint arthroplasty in osteoarthritis

Although total joint replacement (TJR) is a major advance in the treatment of patients with osteoarthritis, its cost-effectiveness has been questioned. We report the results of a study of the costs and benefits of TJR in consecutive osteoarthritis patients, 6 months after the surgery. Health status was measured by the Index of Well-Being. Costs of services for arthritis were determined by interview and billing records. Six months after TJR, significant improvements were seen in global health and in functional status. The average cost of care for the 6 months prior to TJR was $933. The average cost during the 6 months beginning with the TJR was $22,730 per patient--due almost entirely to costs of surgery. In general, the surgery did not change work status, probably because the mean age of the patients was 66.4 years. There were large effectiveness/cost differentials (the larger the effectiveness/cost differential, the higher the degree of cost-effectiveness [CE]). At 6 months, for all patients, the CE was associated with initial health status. The highest CE was observed in 10 patients who initially had the poorest health. TJR is more cost-effective for patients with the most to gain and less effective for those with better preoperative health status.

The centralization of operations and access to treatment: total hip replacement in Manitoba

The impact of centralized facilities on access to care was tested by studying total hip arthroplasty in the Province of Manitoba, Canada. Data from the Manitoba Health Services Commission, which insures costs of all medical services in the Province, show that the availability of this surgical procedure has increased steadily over the 1973-78 period at a rate similar to that elsewhere in North America. Although Manitoba's population is geographically dispersed, specialized orthopedic services are concentrated in two urban centers. No important difference in access to care for this condition was found between urban center residents and residents distant from the surgical facilities.

The measurement iterative loop: a framework for the critical appraisal of need, benefits and costs of health interventions

A framework for organizing health services data is presented that subdivides the spectrum of health information into subgroups that constitute a logical progression from quantifying the burden of illness, through identifying its likely causes, to validating interventions that prevent or ameliorate it and evaluating their efficiency, to monitoring the application of these interventions and coming full-circle to determine whether the burden of illness has been reduced.

Clinical and microbial features of prosthetic joint infection

A one-year experience with prosthetic joint infection, in which 63 cases were identified, is reviewed. Thirty cases (48 percent) were early infections, in the first postoperative year, and 33 cases (52 percent) were late, occurring more than one year after implantation. Pain was the predominant symptom, but clinical clues suggesting infection were frequently absent, with fever in 43 percent and leukocytosis in only 10 percent. The radiographic appearance was more frequently abnormal in late infections (67 versus 37 percent, p less than 0.02). Staphylococci were predominant organisms, constituting 59 percent of prosthetic joint infections, and S. epidermidis was the predominant species in both early and later infections. Of the hematogenous infections, 11 of 13 occurred in the group with late infections; these were mostly nonstaphylococcal . Antigenic proteins of S. epidermidis were characterized by gel electrophoresis, but no infection-specific antigens could be identified when patient serum was compared with normal samples. Precipitating antibodies to the extracellular proteins of S. epidermidis were present in 50 percent of patients with S. epidermidis prosthetic joint infections, 27 percent of patients with nonstaphylococcal infections, 20 percent of patients with S. aureus infections, and 11 percent of normal subjects. In view of the increasing importance of prosthetic joint infection, further study of the pathogenesis of the infection and the host immune response is warranted.

Pathogenesis of foreign body infection. Evidence for a local granulocyte defect

Implanted foreign bodies are highly susceptible to pyogenic infections and represent a major problem in modern medicine. In an effort to understand the pathogenesis of these infections, we studied the phagocytic function in the vicinity of a foreign body by using a recently developed guinea pig model of Teflon tissue cages subcutaneously implanted (Zimmerli, W., F.A. Waldvogel, P. Vaudaux, and U.E. Nydegger, 1982, J. Infect. Dis., 146:487-497). Polymorphonuclear leukocytes (PMN) purified from tissue cage fluid had poor bactericidal activity against a catalase-positive microorganism. When compared with blood or exudate PMN, they exhibited a significant reduction in their ability to generate superoxide in response to a particulate or a soluble stimulus (72 and 57%, respectively, P less than 0.001). Not only their total contents in myeloperoxidase, beta-glucuronidase, lysozyme, and B12 binding protein were significantly reduced (by 62, 21, 47, and 63%, respectively, P less than 0.01), but also their capability for further secretion of residual B12 binding protein upon stimulation. Ingestion rates of endotoxin-coated opsonized oil particles were reduced by 25% (P less than 0.05). In an effort to reproduce these abnormalities in vitro, fresh peritoneal exudate PMN were incubated with Teflon fibers in the presence of plasma. Interaction of PMN with the fibers led to significant increases in hexose monophosphate shunt activity and exocytosis of secondary granules (P less than 0.01). PMN eluted after such interaction showed defective bactericidal activity, oxidative metabolism, and granular enzyme content similar to those observed in tissue cage PMN. The local injection of fresh blood PMN into tissue cages at the time of, or 3 h after, inoculation with 100 microorganisms (Staphylococcus aureus Wood 46) reduced the infection rate from 50 to 56 cages to 1 of 21 (P less than 0.001) and 3 of 8 cages (P less than 0.001), respectively. These results suggest that the in vivo as well as in vitro interaction of PMN with a nonphagocytosable foreign body induces a complex PMN defect, which may be partly responsible for the high susceptibility to infection of foreign bodies.

Secondary osteonecrosis in osteoarthritis of the femoral head

Secondary osteonecrosis was found by pathologic examination in nine (6 per cent) of 150 femoral heads removed surgically for osteoarthritis. The changes were morphologically distinct from the remodeling deformities that supervene late in steroid-induced or idiopathic osteonecrosis. They appeared as infarcts confined to previously eburnated tissue. There were no distinctive clinical or radiologic characteristics. The findings do not lend weight to the hypothesis that unrecognized osteonecrosis is a major etiologic factor in apparently primary osteoarthritis.