Miscoding in the Nationwide Inpatient Sample Database Raises Questions About Validity for Arthroplasty Research.

BACKGROUND: The use of administrative databases in arthroplasty research has increased over the past decade. The Nationwide Inpatient Sample (NIS) is one of the first and most frequently used. Despite many published articles using this dataset, there exists no standardization resource accounting for the potential of biased results. The purpose of our study was to assess the amount of discordant data between clinically relevant variables and propose a standard for using this database in primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: An initial set of patients undergoing total joint arthroplasty were identified from the NIS between 2016 and 2019 using the International Classification of Diseases, 10th Revision, Procedure Coding System. All records with THA and TKA in any of the procedure variables (PR1-PR20) were included. A total of 63 relevant and consistent variables were selected for individual comparison including diagnosis-related group (1), elective (1), procedure codes (20), day of main procedure (1), and diagnosis codes (40). Descriptive statistics were used. A total of 3,562,819 patients were included in the initial set. RESULTS: Using diagnosis-related groups, 5.3% were revision surgeries, 4.7% were not elective, 2.3% did not have THA or TKA as their primary procedure for hospitalization, and 2.9% of THA and 9.7% of TKA were bilateral. A total of 6.2% of the surgeries were done day(s) before or after admission, and 10.8% of THA and 6.3% of TKA were missing an orthopedic diagnosis for admission. Many had multiple orthopedic diagnoses for admission, 3.2% of THA and 0.7% of TKA. Overall miscoding was 23.3%. CONCLUSIONS: Using the NIS without standardized data processing to study elective, unilateral, primary THA and TKA introduces major bias. A logical and stepwise approach to curate the data before analysis is proposed to improve research quality when using this database in hip and knee arthroplasty studies.

Varying Complication Rates and Increased Costs in Technology-Assisted Total Hip Arthroplasty Versus Conventional Instrumentation in 1,372,300 Primary Total Hips.

BACKGROUND: The use of technology allows surgeons increased precision in component positioning in total hip arthroplasty (THA). The objective of this study was to compare (1) perioperative complications and (2) resource utilizations between robotic-assisted (RA) and computer-navigated (CN) versus conventional instrumenttaion (CI) THA. METHODS: A retrospective cohort study was performed using a large national database to identify patients undergoing unilateral, primary elective THA from January 1, 2016 to December 31, 2019 using RA, CN, or CI. There were 1,372,300 total patients identified and included RA (29,735), CN (28,480), and CI (1,314,085) THA. Demographics, complications, lengths of stay, dispositions, and costs were compared between the cohorts. Binary logistic regression analyses were performed. RESULTS: The use of RA THA led to lower rates of intraoperative fracture (0.22% versus 0.39%), delirium (0.1% versus 0.2%), postoperative anemia (14.4% versus 16.7%), higher myocardial infarction (0.13% versus 0.08%), renal failure (1.7% versus 1.6%), blood transfusion (2.0% versus 1.9%), and wound dehiscence (0.02% versus 0.01%) compared to CI THA. The use of CN led to lower rates of respiratory complication (0.5% versus 0.8%), renal failure (1.1% versus 1.6%), blood transfusion (1.3% versus 1.9%), and pulmonary embolism (0.02% versus 0.1%) compared to CI THA. Total costs were increased in RA ($17,729 versus $15,977) and CN ($22,529 versus $15,977). Lengths of hospital stay were decreased in RA (1.8 versus 1.9 days) and CN (1.7 versus 1.9 days). CONCLUSIONS: Perioperative complication rates vary in technology-assisted THA, with higher rates in RA THA and lower rates in CN THA, relative to CI THA. Both RA THA and CN THA were associated with more costs, shorter postoperative hospital stays, and higher rates of discharge home compared to CI THA.

Lower Perioperative Complication Rates and Shorter Lengths of Hospital Stay Associated With Technology-Assisted Total Knee Arthroplasty Versus Conventional Instrumentation in Primary Total Knee Arthroplasty.

BACKGROUND: The use of technology allows increased precision in component positioning in total knee arthroplasty (TKA). The objectives of this study were to compare (1) perioperative complications and (2) resource utilization between robotic-assisted (RA) and computer-navigated (CN) versus conventional (CI) TKA. METHODS: A retrospective cohort study was performed using a national database to identify patients undergoing unilateral, primary elective TKA from January 2016 to December 2019. A total of 2,174,685 patients were identified and included RA (69,445), CN (112,225), or CI (1,993,015) TKA. Demographics, complications, lengths of stay, dispositions, and costs were compared between the cohorts. Binary logistic regression analysis was performed. RESULTS: The RA TKA cohort had lower rates of intraoperative fracture (0.05 versus 0.08%, P < .05), respiratory complications (0.6 versus 1.1%, P < .05), renal failure (1.3 versus 1.7%, P < .05), delirium (0.1 versus 0.2%, P < .05), gastrointestinal complications (0.04 versus 0.09%, P < .05), postoperative anemia (8.9 versus 13.9%, P < .05), blood transfusion (0.4 versus 0.9%, P < .05), pulmonary embolism, and deep vein thrombosis (0.1 versus 0.2%, P < .05), and mortality (0.01 versus 0.02%, P < .05) compared to conventional TKA, though the cohort did have higher rates of myocardial infarction (0.09 versus 0.07%, P < .05). The CN cohort had lower rates of myocardial infarction (0.02 versus 0.07%, P < .05), respiratory complications (0.8 versus 1.1%, P < .05), renal failure (1.5 versus 1.7%, P < .05), blood transfusion (0.8 versus 0.9%, P < .05), pulmonary embolism (0.08 versus 0.2%, P < .05), and deep vein thrombosis (0.2 versus 0.2%, P < .05) over CI TKA. Total cost was increased in RA (16,190 versus $15,133, P < .05) and CN (17,448 versus $15,133, P < .05). However, the length of hospital stay was decreased in both RA (1.8 versus 2.2 days, P < .05) and CN (2.1 versus 2.2 days, P < .05). CONCLUSIONS: Technology-assisted TKA was associated with lower perioperative complication rates and faster recovery.

Prevalence and Spectrum of Occupational Injury Among Orthopaedic Surgeons: A Cross-Sectional Study.

Orthopaedic surgeons are at increased risk for many occupational hazards, both physical and mental. The aim of this study was to evaluate a wide range of work-related injuries among orthopaedic surgeons in the United States. Methods: An electronic survey was developed to assess both physical and mental occupational hazards among orthopaedic surgeons. Descriptive statistics were analyzed for all survey items and compared using chi-square and paired t tests, as appropriate. Results: The 1,645 responding orthopaedic surgeons (7% response rate) reported a total of 2,702 work-related musculoskeletal injuries, 17.9% of which required surgical treatment. Of the 61 who filed a disability claim, only 66% returned to work and 34% retired early. Additionally, 17.4% of respondents reported having been diagnosed with cancer since starting practice, and 93.8% reported experiencing a finger stick at some point in their career. Over one-half (55.8%) had experienced feelings of psychological distress since beginning practice, and nearly two-thirds (64.4%) reported burnout from work. Conclusions: This study captured a spectrum of occupational injuries that pose longitudinal risks to an orthopaedic surgeon's physical and mental well-being. Our hope is that this analysis of occupational hazards will help to raise awareness among the orthopaedic and medical communities and lead to efforts to reduce these risks. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Relative frequency of primary total hip arthroplasty for avascular necrosis in the United States as compared to a regional center: A data review.

Background: The relative frequencies of indications for primary total hip arthroplasty (THA) are not well-established. This study aims to establish the incidence of THA performed for Avascular Necrosis of the hip (AVN), as well as the other most common indications for THA in the United States, as compared to the incidences at a high-volume tertiary referral center in Miami, Florida. We hypothesize that the relative incidence of AVN and each other indication for THA will vary significantly between the United States as a whole and the tertiary referral center. Methods: A query of the 2016-2017 National Inpatient Sample (NIS) and a tertiary referral center adult reconstruction registry was completed. The relative frequencies of each indication for THA, demographics, and behavioral risk factors were analyzed. Results: 225,061 primary THA patients in the National Inpatient Sample database and 447 in the Miami tertiary referral center database were included in the final analysis. The proportion of primary THA for AVN in the NIS database (5.97%) was significantly lower than the same proportion in the tertiary referral center database (22.2%), p < .001. There was no significant difference in the incidence of primary THA for osteoarthritis, inflammatory arthritis, or hip dysplasia between the two populations. Conclusion: The incidence of THA for AVN is significantly different between a tertiary referral center and the greater United States. Patient demographics, race, and behavioral risk factors are associated with the disparity. Orthopaedic surgeons should recognize the differences in THA indication between populations when counseling patients on treatments, outcomes, and the most current literature.

Top 50 most cited articles in revision total hip arthroplasty research.

Background: Bibliometric analysis is a useful tool for measuring the scholarly impact of a topic. To date, there is no such review analyzing the characteristics and trends of publications focused on revision total hip arthroplasty (rTHA). The purpose of this study is to use bibliometric analysis to comprehensively analyze the 50 most cited articles in rTHA research. Methods: This is a cross-sectional study that used the ISI Web of Knowledge database to identify articles published before September 2021. Articles were sorted in descending order by number of citations and those with a focus of rTHA were identified. Of these, the top 50 most cited articles were carried forward for evaluation. Results: The 2000s (50%) and the 1990s (32%) had the greatest volume of contribution. 9 of the top 10 most cited articles were published in the 2000s. The highest impact article had 4702 citations. The level of evidence (LOE) published with the greatest frequency was LOE II (40%) followed by LOE III and LOE IV both recording 24%. The Journal of Bone and Joint Surgery-American Volume had the greatest productivity (46%) followed by The Journal of Bone and Joint Surgery-British Volume (18%). The United States was the country with the highest number of contributions to this list with 56% followed by England (12%), and Sweden and Canada both with 8%. Conclusion: The most impactful articles focusing on rTHA research were comprehensively and objectively analyzed. The most common article type was clinical outcomes (46%) followed by natural history/epidemiology (24%) and surgical technique (16%). While this topic is highly studied with significant level of evidence to support the studies, there is a lack of influential research regarding imaging and clinical guidelines. This analysis can be used by researchers to develop further discussions and build research questions.

Increased Morbidity With Diagnosis and Treatment of Pulmonary Embolism After Total Joint Arthroplasty: A Matched Control Analysis of 30,000 Patients.

BACKGROUND: Currently, the risks associated with the diagnosis of pulmonary embolism (PE) and subsequent treatment are not well known. The purpose of our study is to quantify the specific in-hospital complications and resource utilization of patients with PE following total joint arthroplasty when compared to a matched cohort. METHODS: The Nationwide Inpatient Sample database was used to identify patients undergoing primary hip and knee arthroplasty from January 1993 to December 2008. PE was determined using International Classification of Diseases, Ninth Revision, Clinical Modification codes. In-hospital complications, costs, and length of stay for patients with PE were compared to patients without PE, matched on the basis of age, gender, procedure (total hip arthroplasty vs total knee arthroplasty), year of surgery, morbid obesity, and all 28 comorbid-defined elements of the Elixhauser Comorbidity Index. RESULTS: Of 8,634,038 procedures, 30,281 (0.4%) patients had a PE after total joint arthroplasty. In total, 29,917 (98%) were matched one-to-one with patients without PE. Patients with PE had a substantially higher risk of all postoperative in-hospital complications: deep vein thrombosis (odds ratio [OR] 17), peripheral vascular (OR 34), hematoma (OR 3.7), and gastrointestinal bleeding (OR 7.0) (all P < .001). Mortality was significantly higher in patients with PE compared to patients without PE (3.4% vs 0.1%, OR 30), along with total hospital costs, lengths of stay, and rates of discharge to rehabilitation facilities. CONCLUSION: After controlling for comorbidities patients with PE have a significantly higher risk for complications including in-hospital mortality and higher hospital costs when compared to patient without PE.

Time-Driven Activity-Based Costing in Preoperative Tasks for Total Hip and Knee Arthroplasty.

BACKGROUND: Substantial work in the preoperative phase of total hip arthroplasty (THA) and total knee arthroplasty (TKA) is unaccounted for in current Relative Value Scale Update Committee methodology. A Time-Driven Activity-Based Costing (TDABC) analysis allows for an accurate assessment of the preoperative costs associated with total joint replacement surgery. METHODS: The mean time that clinical staff members spent on preoperative tasks per patient was multiplied by the hourly salary. Clinical staff members included orthopedic surgeons, nurse practitioners or physician assistants, nurses, medical assistants, and surgical coordinators. Mean time spent on preoperative tasks was obtained from the most recent literature. Salaries were obtained from the nationwide database provided by Glassdoor Inc. RESULTS: Total time spent among clinical staff involved in preoperative tasks for each arthroplasty patient was 8.45 hours (2.96-13.94). Total TDABC was calculated to be $348.17 (132.46-562.64). Accounting for preoperative tasks, the TDABC for TKA/THA increases from $13321.5 to $13669.67. Preoperative tasks are composed of 2.6% of total TKA/THA TDABC. In 2020, an estimated $544,189,710 of preoperative TKA/THA work was completed. CONCLUSION: Surgeons, providers, and ancillary staff involved in THA/TKA spend a cumulative preoperative work time of approximately 8.5 hours per patient, which equates to $348.17 that is currently unaccounted for in Relative Value Scale Update Committee methodology.

All-Cause Versus Complication-Specific Readmission Following Total Knee Arthroplasty.

BACKGROUND: Unplanned readmissions have become an important quality indicator, particularly for reimbursement; thus, accurate assessment of readmission frequency and risk factors for readmission is critical. The purpose of this study was to determine (1) the frequency of and (2) risk factors for readmissions for all causes or procedure-specific complications within 30 days after total knee arthroplasty (TKA) as well as (3) the association between hospital volume and readmission rate. METHODS: The Statewide Planning and Research Cooperative System (SPARCS) database from the New York State Department of Health was used to identify 377,705 patients who had undergone primary TKA in the period from 1997 to 2014. Preoperative diagnoses, comorbidities, and postoperative complications were determined using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Readmission was defined as all-cause, due to complications considered by the Centers for Medicare & Medicaid Services (CMS) to be TKA-specific, or due to an expanded list of TKA-specific complications based on expert opinion. Multivariable logistic regression analysis was utilized to determine the independent predictors of readmission within 30 days after surgery. RESULTS: There were 22,076 all-cause readmissions-a rate of 5.8%, with a median rate of 3.9% (interquartile range [Q1, Q3] = 1.1%, 7.2%]) among the hospitals-within 30 days after discharge. Of these, only 11% (0.7% of all TKAs) were due to complications considered to be TKA-related by the CMS whereas 31% (1.8% of all TKAs) were due to TKA-specific complications on the expanded list based on expert opinion. Risk factors for TKA-specific readmissions based on the expanded list of criteria included an age of >85 years (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.15 to 1.52), male sex (OR = 1.41, 95% CI = 1.34 to 1.49), black race (OR = 1.24, 95% CI = 1.14 to 1.34), Medicaid coverage (OR = 1.40, 95% CI = 1.26 to 1.57), and comorbidities. Several comorbid conditions contributed to the all-cause but not the TKA-specific readmission risk. Very low hospital volume (<90 cases per year) was associated with a higher readmission risk. CONCLUSIONS: The frequency of readmissions for TKA-specific complications was low relative to the frequency of all-cause readmissions. Reasons for hospital readmission are multifactorial and may not be amenable to simple interventions. Health-care-quality measurement of readmission rates should be calculated and risk-adjusted on the basis of procedure-specific criteria. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Total Joint Arthroplasty: A Granular Analysis of Outcomes in the Economically Disadvantaged Patient.

BACKGROUND: Poor patients experience more serious complications and worse outcomes after surgery than higher-income patients. Our objective was to study detailed patient sociodemographic characteristics and preoperative/postoperative patient-oriented outcomes in economically disadvantaged and non-economically disadvantaged primary total joint arthroplasty patients. METHODS: From a consecutive series, 213 economically disadvantaged patients and 1940 non-economically-disadvantaged patients were statistically analyzed. Baseline sociodemographic characteristics and pain visual analog scale, Quality of Well-Being Index 7, Short Form 36, and Western Ontario and McMaster Universities Arthritis Index scores recorded before and after surgery were compared between both groups controlling for baseline differences. Minimum follow-up was 1 year. RESULTS: Economically disadvantaged patients were significantly younger, more likely to be disabled, and had worse preoperative and postoperative scores. CONCLUSION: When compared with non-economically disadvantaged patients, economically disadvantaged patients consistently had lower function and worse quality of life before and after total joint arthroplasty.

Assessment of Damage on a Dual Mobility Acetabular System.

BACKGROUND: Dual mobility designs were introduced to increase stability and reduce the risk of dislocation, both being common reasons for surgical revision after total hip arthroplasty. The in vivo behavior of dual mobility constructs remains unclear, and to our knowledge, no data have been published describing in vivo surface damage to the polyethylene bearing surfaces. METHODS: We used surface damage assessed on the inner and outer polyethylene bearing surfaces in 33 short-term retrieved dual mobility liners as evidence of relative motion at the 2 bearings. A lever out test was performed to determine the force required for dislocation of the cobalt-chromium femoral head from the polyethylene liner. RESULTS: Both bearings showed damage; however, the inner polyethylene bearings had higher damage scores, lower prevalence of remaining machining marks, and higher incidence of concentric wear, all consistent with more motion at the inner polyethylene bearing. The inner polyethylene bearings also had a higher occurrence of embedded titanium debris. The damage sustained in vivo was insufficient to lead to intraprosthetic dislocation in any of the retrieved components. Lever out tests of 12 retrievals had a mean dislocation load of 261 ± 52 N, which was unrelated to the length of implantation. CONCLUSION: Our short-term retrieval data of 33 highly cross-linked polyethylene dual mobility components suggest that although motion occurs at both bearing articulations, the motion of the femoral head against the inner polyethylene bearing dominates. Although damage was not severe enough to lead to intraprosthetic dislocation, failure may occur long term and should be assessed in future studies.

Lack of early dislocation following total hip arthroplasty with a new dual mobility acetabular design.

Dual mobility implant designs minimise the risk of dislocation without sacrificing range of motion. Between 1st September 2008 and 31st July 2011, 5 institutions examined early clinical outcomes of a new dual mobility bearing hip system implanted in 485 primary THAs in 452 patients. Patient demographics were 46% female, a mean age of 67 years and a mean BMI of 30. Complications at a minimum of 2 years after surgery included 1 femur fracture, 1 DVT and 4 unrelated deaths. There were no dislocations. For functional outcomes, Harris Hip Scores increased from 41 to 86 (p<0.001), while VAS pain scores decreased from 5.9 to 0.7 (p<0.001). Minimal complications, excellent early clinical outcomes and the absence of early dislocations demonstrate the improved stability of this dual mobility implant system.

Medicaid payer status is associated with in-hospital morbidity and resource utilization following primary total joint arthroplasty.

BACKGROUND: Previous reports suggest that there are major disparities in outcomes following total joint arthroplasty among patients with different payer statuses. The explanation for these differences is largely unknown and may result from confounding variables. The Affordable Care Act expansion of Medicaid coverage in 2014 makes the examination of these disparities particularly relevant. METHODS: The Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database was used to identify patients who had undergone primary hip or knee arthroplasty from 2002 through 2011. Complications, costs, and length of hospital stay for patients with Medicaid were compared with those for non-Medicaid patients. Each Medicaid patient was matched to a non-Medicaid patient according to age, sex, race, type of total joint arthroplasty, procedure year, hospital characteristics, smoking status, and all twenty-nine comorbidities defined in the NIS-modified Elixhauser comorbidity measure. RESULTS: It was determined that 191,911 patients who underwent total joint arthroplasty had Medicaid payer status (2.8% of the entire total joint arthroplasty population), and 107,335 (56%) of these Medicaid patients were matched one to one to a non-Medicaid patient for all variables for the adjusted analysis. After matching, Medicaid patients were found to have a higher prevalence of postoperative in-hospital infection (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.3 to 2.1), wound dehiscence (OR, 2.2; 95% CI, 1.4 to 3.4), and hematoma or seroma (OR, 1.3; 95% CI, 1.2 to 1.4) but a lower risk of cardiac complications (OR, 0.7; CI, 0.6 to 0.9). The length of the hospital stay was longer, total cost was higher, and discharge to an inpatient facility was more frequent for patients with Medicaid status (p < 0.01). CONCLUSIONS: Compared with non-Medicaid patients, Medicaid patients have a significantly higher risk for certain postoperative in-hospital complications and consume more resources following total joint arthroplasty even when the two groups have been matched for patient-related factors and comorbid conditions commonly associated with low socioeconomic status. Additional work is needed to understand the complex interplay between socioeconomic status and outcomes, to ensure appropriate resources are allocated to maintain access for this patient population, and to develop appropriate risk stratification.

Relative head size increase using an anatomic dual mobility hip prosthesis compared to traditional hip arthroplasty: impact on hip stability.

Smaller head sizes and head/cup ratios make cups smaller than 50mm and larger than 58mm, more prone to dislocation. Using computer modeling, we compared average head sizes and posterior horizontal dislocation distance (PHDD) in two 78-patient matched cohorts. Cup sizes were small (≤50mm) or large (≥58mm). The control cohort had conventional fixed bearing prostheses, while the experimental cohort had anatomical dual mobility (ADM) hip prostheses. ADM cups have larger average head sizes and PHDD than traditional fixed bearing prostheses by 11.5mm and 80% for cups ≤50mm, and 16.3mm and 90% for cups ≥58mm. Larger head sizes and increased head/cup ratio may allow the ADM prosthesis to reduce the incidence of dislocation.

Obstructive sleep apnea as a risk factor for postoperative complications after revision joint arthroplasty.

Although current evidence is limited, obstructive sleep apnea (OSA) has been suggested as a risk factor for morbidity after primary joint arthroplasty. Our objective was to determine if patients with OSA have a higher likelihood of postoperative in-hospital complications or increased costs after revision arthroplasty. The Nationwide Inpatient Sample was used to identify 258,455 patients who underwent revision total hip arthroplasty or revision total knee arthroplasty between 2006 and 2008. Of these patients, 16,608 (6.4%) had been diagnosed with OSA. Multivariate analysis with logistic regression modeling was used to compare patients with and without OSA. Obstructive sleep apnea was associated with increased in-hospital mortality (odds ratio, 1.9; P = .002), pulmonary embolism (odds ratio, 2.1; P = .001), wound hematomas or seromas (odds ratio, 1.36; P < .001), and increased postoperative charges ($61,044 vs $58,813; P < .001). Further research is warranted.

Management of failed metal-on-metal total hip arthroplasty.

The theoretical advantages of metal-on-metal (MOM) bearing couples in total hip arthroplasty (THA) have been recently balanced by concerns regarding adverse local and systemic effects. Higher than anticipated early revision rates have been reported by several joint registries. Failed MOM hips present with a spectrum of symptoms and findings and traditional methods of failure must be considered in addition to the failure modes that appear to be unique to the MOM bearing couple. Metal hypersensitivity and soft tissue immune reactions remain incompletely understood and require careful ongoing study. The tools available to evaluate MOM THAs and the indications for revision surgery remain to be defined. Outcomes following revision of MOM hips appear to depend on appropriate evaluation, early identification, and appropriate surgical management.

Primary total knee arthroplasty in patients with fibromyalgia.

No data on the results of total knee arthroplasty (TKA) in patients with fibromyalgia have been published. The purposes of this study were to review a cohort of patients with fibromyalgia undergoing TKA to determine the level of postoperative pain and satisfaction with the surgery, the incidence of postoperative surgical complications, and revision rates and their relationship to TKA design. One hundred ten patients with fibromyalgia (141 knees) who underwent primary TKA between 1990 and 2001 were studied. The average age was 64 years (range, 39-86 years), and the average follow-up was 7 years (range, 2-16 years). Forty-five knees were cruciate retaining, and 96 had a posterior stabilized design. Clinical outcome was assessed using the Knee Society Knee Score and satisfaction regarding the results of the procedure. Postoperative surgical complications and reoperations were obtained from the registry. Sixty-two patients (44%) continued with some pain after TKA. Eighty-five patients (82%) were satisfied with the results. The most common complications were arthrofibrosis and symptomatic instability. The revision rate was 6% (8 knees). Survivorship free from revision at 7 years was 89% for cruciate retaining knees and 98% for posterior stabilized knees. Patients with fibromyalgia undergoing primary TKA have a high prevalence of complications and pain. Despite continued pain, the majority of patients were satisfied with the results and reported improvements after TKA. This data should be used to counsel patients with fibromyalgia preoperatively regarding limited goals with respect to pain relief and suggests that a multimodal individualized treatment program may be necessary to achieve optimal outcomes in patients with fibromyalgia.

Is postoperative function after hip or knee arthroplasty influenced by preoperative functional levels?

Our objective was to evaluate functional outcomes after surgery in a subgroup of patients presenting for hip and knee surgery who had low functional scores before surgery. One hundred twenty-seven unilateral total hip and knee arthroplasty patients were assessed preoperatively and 3 consecutive years after arthroplasty using: Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Short Form 36 (SF-36), and the Quality of Well-Being index scales. Patients were placed into 2 groups based on preoperative WOMAC function scores; 51 points or more, worse functioning group, and less than 51 points, higher functioning group. Regardless of time, the worse functioning group in both procedures performed worse on the Quality of Well-Being index, SF-36 (function score), SF-36 (social score), and WOMAC total and pain scores (P < or = .0001). The greatest change (range, 2%-638%) for all variables in both groups for both procedures occurred during the first year. Patients that had severe/extreme functional impairment had worse 3-year outcomes compared with patients getting surgery when their functional levels were better.

Revision total hip arthroplasty in octogenarians. A case-control study.

BACKGROUND: Revision total hip arthroplasty in the very elderly is believed to be associated with a high complication rate. We evaluated the early outcomes and prevalence of complications following revision total hip arthroplasty in patients older than eighty years of age and compared them with those in a younger patient population. METHODS: We retrospectively reviewed the results of 170 revision total hip arthroplasties that had been performed in 159 octogenarians in our institute between 1992 and 1999. The mean patient age at the time of surgery was 83.8 years, and the mean follow-up time was 6.8 years. We then compared these results with those of 170 revision total hip arthroplasties, done with the same surgical technique and prosthesis, in 162 patients who were seventy years old or younger and followed for a mean of six years. The functional outcome and the quality of life following the arthroplasties were assessed with use of the Harris hip score and the Short Form-36 (SF-36), respectively. Risk factors for complications and mortality were identified, and Kaplan-Meier analysis was used to determine survivorship. RESULTS: The octogenarians had a significant improvement in the mean Harris hip score, from 47 points preoperatively to 85 points at the time of the latest follow-up. In the control group, the Harris hip score also improved significantly, from a preoperative mean of 44.3 points to a mean of 87.9 points at the time of the latest follow-up. There was no significant difference between the two groups in the magnitude of improvement of the Harris hip score. There were 100 deaths (a rate of 58.8%) at a mean of 5.3 years postoperatively in the octogenarian group compared with twelve deaths (7.1%) in the control group (p < 0.0001). There were no intraoperative deaths in either group. Of the 100 octogenarian patients who died, 94% had a well-functioning hip at the time of death. Perioperative medical complications developed in thirty patients (thirty-eight hips [22.4%]) in the octogenarian group and in twenty-five patients (twenty-six hips [15.3%]) in the control group (p > 0.05). There were thirteen repeat revisions and four other types of reoperations in the octogenarian group and twenty-three repeat revisions and six other types of reoperations in the control group (p = 0.08). A dislocation was sustained by four patients in the octogenarian group and sixteen patients in the control group (p = 0.01). CONCLUSIONS: Revision total hip arthroplasty can provide substantial clinical benefit to patients over eighty years of age. The medical complication rate for octogenarians may not differ significantly from that for patients seventy years of age or younger, and the prevalence of technical complications and dislocations can be expected to be lower than that for younger patients.

Patellar meniscus in total knee arthroplasty.

Twenty-four clinically successful, autopsy retrieved porous-coated anatomic total knee arthroplasty (TKA) specimens were evaluated to determine the structure and function of the patellar meniscus. Mean implant duration was 76 months (range: 11-135 months). Histological examination showed the patellar meniscus to be composed of dense fibrous tissue with scattered regions of chronic granulomatous response to polyethylene debris. Patellar wear and polyethylene exposed patellar surface area were correlated with implant duration (r = 0.47, P = .03; r = 0.52, P = .06). Postoperative patellar tilt was also associated with patellar component wear (r = 0.64, P = .03). No other clinical measures were significantly associated with patellar wear or exposed surface area. Additional research is needed to determine what role, if any, the patellar meniscus plays in TKA outcomes.