Search

Background: Medicare Advantage (MA) plans are popular among Medicare-eligible patients, but little is known about MA in lower-extremity total joint arthroplasty (TJA). The purpose of this study was to describe trends in MA utilization and analyze differences in patient characteristics and postoperative outcomes between patients undergoing primary TJA using traditional Medicare (TM) or MA plans.Methods: Patients ≥65 years of age who underwent primary total knee or total hip arthroplasty were identified using the Premier Healthcare Database. Patients were categorized into TM and MA cohorts. Data from 2004 to 2020 were used to describe trends in insurance coverage. Data from 2015 to 2020 were used to identify differences in patient characteristics and postoperative complications using ICD-10 codes. Multivariate analyses were performed using 2015 to 2020 data to account for potential confounders.Results: From 2004 to 2020, the proportion of patients with MA increased from 7.9% to 34.4%, while those with TM decreased from 83.7% to 54.0%. Of the 697,317 patients who underwent primary elective TJA from 2015 to 2020, 471,439 (67.6%) had TM coverage and 225,878 (32.4%) had MA coverage. The cohorts were similar in terms of age and sex. However, a higher proportion of Black patients (8.29% compared with 4.62%; p < 0.001) and a lower proportion of White patients (84.0% compared with 89.2%; p < 0.001) were enrolled in MA compared with TM. After controlling for confounders, patients with MA had higher odds of surgical site infection (adjusted odds ratio [aOR]: 1.15; 95% confidence interval [CI]: 1.04 to 1.47; p = 0.031), periprosthetic joint infection (aOR: 1.10; 95% CI: 1.03 to 1.18; p = 0.006), stroke (aOR: 1.15; 95% CI: 1.02 to 1.31; p = 0.026), and acute kidney injury (aOR: 1.08; 95% CI: 1.04 to 1.11; p < 0.001), but lower odds of urinary tract infection (aOR: 0.94; 95% CI: 0.90 to 0.98; p = 0.003).Conclusions: From 2004 to 2020, the number of patients utilizing MA increased markedly such that 1 in 3 were covered by MA in 2020. From 2015 to 2020, patients who were non-White were more likely to have MA than TM, and the MA group had a higher rate of several postoperative complications compared with the TM group. As TM claims data inform health-care policy and clinical decisions, this change portends future challenges, including limitations in arthroplasty registry research, an increase in the administrative burden of surgeons, and a potential worsening of social disparities in health care. [ABSTRACT FROM AUTHOR]

Anterior skin numbness from injury of the infrapatellar branch of saphenous nerve (IPBSN) and/or the anterior-inferior branch of the femoral cutaneous nerve (AIBFN) has been reported after TKA. A recent study has demonstrated no difference in skin numbness between minimally invasive and standard approach TKA. The purpose of our study was to compare the area of skin numbness following TKA in the diabetic and non-diabetic patient. 120 patients (41 type II diabetic and 74 non-diabetic) undergoing TKA were evaluated. Five diabetic patients with preoperative skin numbness were excluded. Area of anterior skin numbness was periodically evaluated with a minimum 2-year follow-up (FU). Clinically, there was no difference in prevalence of skin numbness (73.2% vs 68.9%, p = 0.36) and warmness (97.6% vs 97.3%, p = 1.00) between diabetics and non-diabetics. Average area of numbness was comparable. However, duration of numbness recovery was significantly longer in diabetics (8.6 vs 5.3 months, p = 0.001). Diabetics had a higher rate of global anterior numbness (48.3% vs 22.9%, p = 0.045). Prevalence of supero-lateral skin numbness (2.6%, n = 3) correlated with the skin incision extended proximally above upper pole of patella at least 4.0 cm The duration of numbness recovery following TKA was significantly longer in diabetic patients. [ABSTRACT FROM AUTHOR]

Background: Use of large clinical and administrative databases for orthopaedic research has increased exponentially. Each database represents unique patient populations and varies in their methodology of data acquisition, which makes it possible that similar research questions posed to different databases might result in answers that differ in important ways.Questions/purposes: (1) What are the differences in reported demographics, comorbidities, and complications for patients undergoing primary TKA among four databases commonly used in orthopaedic research? (2) How does the difference in reported complication rates vary depending on whether only inpatient data or 30-day postoperative data are analyzed?Methods: Patients who underwent primary TKA during 2010 to 2012 were identified within the National Surgical Quality Improvement Programs (NSQIP), the Nationwide Inpatient Sample (NIS), the Medicare Standard Analytic Files (MED), and the Humana Administrative Claims database (HAC). NSQIP is a clinical registry that captures both inpatient and outpatient events up to 30 days after surgery using clinical reviewers and strict definitions for each variable. The other databases are administrative claims databases with their comorbidity and adverse event data defined by diagnosis and procedure codes used for reimbursement. NIS is limited to inpatient data only, whereas HAC and MED also have outpatient data. The number of patients undergoing primary TKA from each database was 48,248 in HAC, 783,546 in MED, 393,050 in NIS, and 43,220 in NSQIP. NSQIP definitions for comorbidities and surgical complications were matched to corresponding International Classification of Diseases, 9 Revision/Current Procedural Terminology codes and these coding algorithms were used to query NIS, MED, and HAC. Age, sex, comorbidities, and inpatient versus 30-day postoperative complications were compared across the four databases. Given the large sample sizes, statistical significance was often detected for small, clinically unimportant differences; thus, the focus of comparisons was whether the difference reached an absolute difference of twofold to signify an important clinical difference.Results: Although there was a higher proportion of males in NIS and NSQIP and patients in NIS were younger, the difference was slight and well below our predefined threshold for a clinically important difference. There was variation in the prevalence of comorbidities and rates of postoperative complications among databases. The prevalence of chronic obstructive pulmonary disease (COPD) and coagulopathy in HAC and MED was more than twice that in NIS and NSQIP (relative risk [RR] for COPD: MED versus NIS 3.1, MED versus NSQIP 4.5, HAC versus NIS 3.6, HAC versus NSQIP 5.3; RR for coagulopathy: MED versus NIS 3.9, MED versus NSQIP 3.1, HAC versus NIS 3.3, HAC versus NSQIP 2.7; p < 0.001 for all comparisons). NSQIP had more than twice the obesity as NIS (RR 0.35). Rates of stroke within 30 days of TKA had more than a twofold difference among all databases (p < 0.001). HAC had more than twice the rates of 30-day complications at all endpoints compared with NSQIP and more than twice the 30-day infections as MED. A comparison of inpatient and 30-day complications rates demonstrated more than twice the amount of wound infections and deep vein thromboses is captured when data are analyzed out to 30 days after TKA (p < 0.001 for all comparisons).Conclusions: When evaluating research utilizing large databases, one must pay particular attention to the type of database used (administrative claims, clinical registry, or other kinds of databases), time period included, definitions utilized for specific variables, and the population captured to ensure it is best suited for the specific research question. Furthermore, with the advent of bundled payments, policymakers must meticulously consider the data sources used to ensure the data analytics match historical sources.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

ABSTRACT Multiple assessments are used clinically after total knee arthroplasty (TKA) including self-report, performance tasks, and physical activity levels. It is unclear if these different functional assessments are interchangeable or if they measure different constructs. The objective of this study was to characterize different functional measures before and after TKA. We characterized function before and after TKA using perceived function (KOOS ADL), physical performance (gait speed), and daily activity (steps/day via accelerometry); compared function in people undergoing TKA to age-matched healthy controls; and examined characteristics of those undergoing TKA for potential predictors of postoperative function. Prior to TKA, all three functional assessments were significantly lower for participants than those of healthy controls and each measure remained lower for participants than for controls postoperatively. All three functional assessments developed differently over time postoperatively. Each functional outcome had a unique set of predictors. Perceived function was predicted primarily by anxiety and depression, physical performance was most strongly predicted by age, and daily activity was chiefly predicted by BMI. Pressure pain threshold was a common predictor across all models. Functional limitations exist preoperatively and persist postoperatively across different measures in people undergoing TKA when compared to those measures in healthy controls. Functional outcomes after TKA are different depending on the functional measure utilized, implying that different constructs underlie each measure. Multiple functional measures should be assessed to provide a more comprehensive assessment of function after TKA. Further work should assess the impact of interventions designed to treat modifiable predictors of postoperative TKA function. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2790-2798, 2017. [ABSTRACT FROM AUTHOR]

The current study aimed to examine the relationships between movement and resting pain intensity, pain-related distress, and psychological distress in participants scheduled for total knee arthroplasty (TKA). This study examined the impact of anxiety, depression, and pain catastrophizing on the relationship between pain intensity and pain-related distress. Data analyzed for the current study (N = 346) were collected at baseline as part of a larger Randomized Controlled Trial investigating the efficacy of TENS for TKA (TANK Study). Participants provided demographic information, pain intensity and pain-related distress, and completed validated measures of depression, anxiety, and pain catastrophizing. Only 58% of the sample reported resting pain >0 while 92% of the sample reported movement pain >0. Both movement and resting pain intensity correlated significantly with distress (rs = .86,p < .01 and .79,p < .01, respectively). About three quarters to two thirds of the sample (78% for resting pain and 65% for movement pain) reported different pain intensity and pain-related distress. Both pain intensity and pain-related distress demonstrated significant relationships with anxiety, depression, and catastrophizing. Of participants reporting pain, those reporting higher anxiety reported higher levels of distress compared to pain intensity. These findings suggest that anxious patients may be particularly distressed by movement pain preceding TKA. Future research is needed to investigate the utility of brief psychological interventions for pre-surgical TKA patients. [ABSTRACT FROM PUBLISHER]

Background: Infection after total knee arthroplasty (TKA) can result in disastrous consequences. Previous research regarding injections and risk of TKA infection have produced conflicting results and in general have been limited by small cohort size.Questions/purposes: The purpose of this study was to evaluate if intraarticular injection before TKA increases the risk of postoperative infection and to identify if time between injection and TKA affect the risk of TKA infection.Methods: The Humana data set was reviewed from 2007 to 2014 for all patients who received a knee injection before TKA. Current Procedural Terminology (CPT) codes and laterality modifiers were used to identify patients who underwent knee injection followed by ipsilateral TKA. Postoperative infection within 6 months of TKA was identified using International Classification of Diseases, 9th Revision/CPT codes that represent two infectious endpoints: any postoperative surgical site infection (encompasses all severities of infection) and operative intervention for TKA infection (surrogate for deep TKA infection). The injection cohort was stratified into 12 subgroups by monthly intervals out to 12 months corresponding to the number of months that had elapsed between injection and TKA. Risk of postoperative infection was compared between the injection and no injection cohorts. In total, 29,603 TKAs (35%) had an injection in the ipsilateral knee before the TKA procedure and 54,081 TKA cases (65%) did not. The PearlDiver database does not currently support line-by-line output of patient data, and so we were unable to perform a multivariate analysis to determine whether other important factors may have varied between the study groups that might have had a differential influence on the risk of infection between those groups. However, the Charlson Comorbidity index was no different between the injection and no injection cohorts (2.9 for both) suggesting similar comorbidity profiles between the groups.Results: The proportion of TKAs developing any postoperative infection was higher among TKAs that received an injection before TKA than in those that did not (4.4% versus 3.6%; odds ratio [OR], 1.23; 95% confidence interval [CI], 1.15-1.33; p < 0.001). Likewise, the proportion of TKAs developing infection resulting in return to the operating room after TKA was also higher among TKAs that received an injection before TKA than those that did not (1.49% versus 1.04%; OR, 1.4; 95% CI, 1.3-1.63; p < 0.001). Month-by-month analysis of time between injection and TKA revealed the odds of any postoperative infection remained higher for the injection cohort out to a duration of 6 months between injection and TKA (ORs ranged 1.23 to 1.46 when 1-6 months between injection and TKA; p < 0.05 for all) as did the odds of operative intervention for TKA infection when injection occurred within 7 months of TKA (OR ranged from 1.38 to 1.88 when 1-7 months between injection and TKA; p < 0.05 for all). When the duration between injection and TKA was longer than 6 or 7 months, the ORs were no longer elevated at these endpoints, respectively.Conclusions: Injection before TKA was associated with a higher risk of postoperative infection and appears to be time-dependent with closer proximity between injection and TKA having increased odds of infection. Further research is needed to better evaluate the risk injection before TKA poses for TKA infection; a more definitive relationship could be established with a multivariate analysis to control for other known risk factors for TKA infection.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Total joint arthroplasty is the most frequently performed orthopaedic procedure in the United States. The purpose of the present study was to identify differences in thirty-day morbidity and mortality following primary total hip and total knee arthroplasty according to smoking status and pack-year history of smoking. Methods: We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database to identify patients who had undergone primary total hip or total knee arthroplasty between 2006 and 2012. Patients were stratified by smoking status and pack-year history of smoking. Thirty-day rates of mortality, wound complications, and total complications were compared with use of univariate and multivariate analyses. Results: We identified 78,191 patients who had undergone primary total hip or total knee arthroplasty. Of these, 81.8% (63,971) were nonsmokers, 7.9% (6158) were former smokers, and 10.3% (8062) were current smokers. Current smokers had a higher rate of wound complications (1.8%) compared with former smokers and nonsmokers (1.3% and 1.1%, respectively; p < 0.001). Former smokers had a higher rate of total complications (6.9%) compared with current smokers and nonsmokers (5.9% and 5.4%, respectively; p < 0.001). Multivariate analysis identified current smokers as being at increased risk of wound complications (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.21 to 1.78), particularly deep wound infection, while both current smokers (OR, 1.18; 95% CI, 1.06 to 1.31) and former smokers (OR, 1.20; 95% CI, 1.08 to 1.34) were at increased total complication risk. Increasing pack-year history of smoking resulted in increasing total complication risk. Conclusions: On the basis of our findings, current smokers have an increased risk of wound complications and both current and former smokers have an increased total complication risk following total hip or total knee arthroplasty. [ABSTRACT FROM AUTHOR]

Background: Knee arthroplasty has emerged as an effective treatment for end-stage gonarthrosis. Although total knee arthroplasty remains the gold standard, unicompartmental knee arthroplasty is an appropriate alternative for select patients. We sought to use a large, heterogeneous national database to identify differences in thirty-day complication rates between unicompartmental and total knee arthroplasty as well as to identify risk factors for complications. Methods: Patients in the ACS NSQIP (American College of Surgeons National Surgical Quality Improvement Program) database who had undergone total or unicompartmental knee arthroplasty from 2005 to 2011 were identified. CPT (Current Procedural Terminology) codes were used to select cases of elective primary knee arthroplasty. Statistical models employing univariate and multivariate logistic regression identified risk factors associated with the thirty-day incidence of morbidity and mortality after total and unicompartmental knee arthroplasty. Propensity score matching addressed demographic differences between the total and unicompartmental knee arthroplasty cohorts. Results: A total of 29,333 patients were identified; 27,745 (94.6%) underwent total knee arthroplasty and 1588 (5.41%) underwent unicompartmental knee arthroplasty. Prior to matching, the total knee arthroplasty cohort was 63.7% female and had a mean BMI of 32.8 ± 7.3 kg/m2, whereas the values for the unicompartmental cohort were 55.3% and 31.5 ± 6.5 kg/m2 (p < 0.0001). The mean ages of these cohorts were 67.2 ± 10.1 and 64.0 ± 10.7 years, respectively (p < 0.0001). A previously developed and implemented propensity score matching algorithm was used to address the demographic differences. Following matching, the total complication rate did not differ significantly between the total and unicompartmental knee arthroplasty cohorts (5.29% compared with 4.16%, p = 0.35), whereas the rate of deep venous thrombosis (1.50% compared with 0.50%, p = 0.02) and the duration of hospital stay (3.4 compared with 2.2 days, p < 0.0001) were significantly higher in the total knee arthroplasty cohort. Conclusions: Comparison of total and unicompartmental knee arthroplasty revealed no differences in overall short-term (thirty-day) morbidity and mortality. Although this study does not address long-term subjective outcomes or implant survival, these findings should provide helpful information for surgeons counseling patients considering total and/or unicompartmental knee arthroplasty. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Most long-term followup studies of younger patients who underwent TKA include a relatively high percentage of rheumatoid patients, whose function and implant durability may differ from those with osteoarthritis (OA). Questions/purposes: The purpose of this study was to evaluate the minimum 10 year followup of TKA performed in more active patients with OA, using modular tibial components, to determine the durability of that construct. Specifically, we determined (1) survivorship; (2) revision rates; (3) functional scores; and (4) rates of radiographic failure at a minimum 10 year followup. Methods: We retrospectively reviewed 59 patients (67 knees) with OA who underwent primary total knee arthroplasty with posterior cruciate retaining (27%) or posterior cruciate substituting (73%) components which had modular tibial trays. Patients were evaluated clinically for need of revision and Knee Society, SF-36 and WOMAC scores as well as UCLA and Tegner activity scores. Radiographs were evaluated for loosening and osteolysis. The minimum followup of living patients was 10 years (mean, 12.4 years; range, 10 to 18.4 years). Ten patients (11 knees) died; two patients (2 knees) were lost to followup. Results: Ten patients (11 knees; 16%) had revisions for aseptic loosening and/or osteolysis. Thirty-one patients (65%) were still performing moderate labor or sports activities. The average UCLA score was 5.5 (range, 2-9). No nonrevised knee demonstrated radiographic loosening. Conclusion: Most patients in this active patient population continued to have acceptable function although 16% underwent revision for wear and/or osteolysis. Isolated tibial insert exchange alone was performed in four of the 11 (36%) revised knees. These data should provide comparison for total knee arthroplasties performed in younger patients with newer designs and newer bearing materials. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Liner exchange and bone grafting are commonly performed for wear and osteolysis around well-fixed modular acetabular components that otherwise would require structural allografting and revision THA. However, liner exchange in the face of substantial lysis around TKA has been performed rarely with reports of failure rates of up to 25% at 3 year followup. Questions/purposes: We therefore evaluated the technique of liner exchange and bone grafting for cases of wear and extensive osteolysis around TKAs in which the components were well-fixed and well-aligned to determine (1) rerevision rates; (2) fate of the bone graft; (3) radiographic loosening rates; and (4) functional scores. Methods: We retrospectively reviewed 22 patients (25 knees) who underwent revision TKA with exchange of the modular polyethylene insert and bone grafting in cases with well-fixed components and large areas of osteolysis (up to 54 cm on a single projection) at the time of revision. The average area of osteolysis was 21 cm and 10 cm on the AP projection of the femur and tibia, respectively. On the lateral projection, the average area of osteolysis for the femur and tibia was 22 cm and 9.3 cm. Minimum clinical and radiographic followup was 22 and 22 months (average, 61 and 59; range, 22-142 and 22-130, respectively). Results: One of the 25 knees was revised for aseptic loosening or recurrence of osteolysis. On radiographs, 84.6% and 70% of femoral and tibial osteolytic lesions, respectively, showed evidence of complete or near complete graft incorporation. The remaining lesions showed evidence of partial graft incorporation with the exception of one tibial lesion, which was in the revised case. All other components were well fixed with no evidence of radiographic loosening. Conclusions: In this selected series of cases with extensive osteolysis around well-fixed and well-aligned TKAs, liner exchange and bone grafting provided durable midterm results with extensive graft incorporation. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

We previously evaluated 119 consecutive total knee arthroplasties performed by a single surgeon in eighty-six patients with use of the cemented LCS (low contact stress) mobile-bearing, rotating-platform system and an all-polyethylene patellar component. The average age of the patients at the time of surgery was seventy years. The patients were contacted as part of their routine follow-up and were asked to participate in this study. The purpose of the present study was to report the updated results at a minimum follow-up of twenty years. Twenty patients (twenty-six knees) were living, and one was lost to follow-up. Three knees required a reoperation (two for periprosthetic fractures and one for infection). No component was revised as a part of the reoperations. No knee required revision since the fifteen-year follow-up evaluation. Osteolysis was present in six knees compared with only three knees at the time of the fifteen-year follow-up. One knee had radiographic signs of femoral component loosening, which was associated with osteolysis. It occurred after the fifteen-year follow-up study. The average range of motion was from 1° of extension to 105° of flexion. The average clinical and functional Knee Society scores were 43 and 49 points, respectively, at the preoperative evaluation and 89 and 67 points at the time of the final follow-up. We concluded that the cemented LCS rotating-platform knee performed well, with durable clinical and radiographic results at a minimum follow-up of twenty years. However, the prevalence of osteolysis continues to increase with a longer duration of follow-up in these patients. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Abstract: We previously evaluated 119 consecutive total knee arthroplasties that were performed in eighty-six patients with use of the cemented LCS (low contact stress) rotating-platform system with an all-polyethylene patellar component. The average age of the patients at the time of surgery was seventy years (range, thirty-seven to eighty-eight years). The purpose of this study was to report the updated results at a minimum follow-up of fifteen years. Thirty-seven patients (fifty-three knees) were living, and no patient was lost to follow-up. No knee was revised because of loosening, osteolysis, or wear. Three knees required a reoperation (two for periprosthetic fractures and one for infection). No component was revised as a part of the reoperations. Osteolysis was present in three knees. No knee had radiographic signs of component loosening, and there were no dislocated bearings. The average range of motion was from 1 ° of extension to 105 ° of flexion. The average clinical and functional Knee Society scores were 43 and 49, respectively, at the preoperative evaluation and 85 and 58 at the time of the final follow-up. We concluded that the cemented LCS rotating-platform knee performed well, with durable clinical and radiographic results at a minimum follow-up of fifteen years. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate the types and prevalence of complications associated with bilateral total knee replacement performed four to seven days apart during a single hospitalization and to compare them with those associated with bilateral knee replacement performed sequentially under the same anesthetic session or staged unilateral replacements performed during separate hospitalizations. Methods: Using a computerized database and medical records, we retrospectively evaluated 332 consecutive patients who underwent bilateral total knee replacement performed by two surgeons. A total of 241 patients underwent staggered bilateral knee replacement with the procedures performed four to seven days apart during one hospitalization, twenty-six underwent sequential bilateral total knee replacement, and sixty-five underwent staged bilateral knee replacement performed during two separate hospitalizations. The data on major complications, including death, return to operating room, myocardial infarction, and pulmonary embolism, and on minor complications, including atrial fibrillation, deep-vein thrombosis, and urinary tract infection, were evaluated. Results: Patients undergoing sequential bilateral total knee replacement and staged bilateral knee replacement had an overall rate of complications that was 2.5 times higher than that of the staggered group. Major complications were rare in all groups, but they occurred most often in the staged bilateral replacement group. The overall rate of complications for the patients who had staggered bilateral knee replacement (13%) was significantly less (p = 0.0009) than that for the patients who had sequential bilateral knee replacement (35%) or staged bilateral knee replacement (31%). The length of inpatient stay for those with staggered total knee arthroplasty was four days longer than that for the sequential arthroplasty group (p = 0.0001). Conclusions: Staggered bilateral total knee replacement, with the procedures performed four to seven days apart in a single hospitalization, is a safe and practical method for performing bilateral total knee replacement. [ABSTRACT FROM AUTHOR]

Background: Most intermediate and long-term studies of cemented posterior-cruciate-substituting total knee prostheses were performed with nonmodular tibial components. The purpose of this study was to evaluate the intermediate-term results of posterior-cruciate-substituting total knee arthroplasties in which a cemented modular tibial component had been used, with a particular focus on evaluating the prevalence of radiographic osteolysis. Methods: Between 1992 and 1995, 176 consecutive primary total knee arthroplasties with use of the Insall-Burstein II system were performed in 134 patients at our institution. A modular metal-backed tibial component was inserted in 145 knees, and an all-polyethylene tibial component of the same design was inserted in thirty-one. Standard-terminology questionnaires were completed or Knee Society and The Hospital for Special Surgery scores were determined preoperatively and at the time of final follow-up, at an average of 6.4 years (range, 5.0 to 7.9 years). Initial postoperative radiographs were compared with those made at the time of final follow-up to assess component position, wear, radiolucent lines, and osteolysis. Results: Ninety-two patients (128 knees) treated with the modular tibial component were alive at the time of final follow-up. No patient was lost to follow-up. Radiographs were available for 105 knees (82%). Three knees had been revised because of instability or infection; none had been revised because of loosening or osteolysis. The mean Knee Society clinical and functional scores were 85 points (range, 41 to 100 points) and 79 points (range, 30 to 100 points), respectively, at the time of final follow-up. According to The Hospital for Special Surgery score, 94% of the knees had a good or excellent result. Knee flexion averaged 113° (range, 90° to 130°) at the time of final follow-up. Osteolysis was present in seventeen (16%) of the knees with radiographic follow-up. Osteolysis did not develop in any... [ABSTRACT FROM AUTHOR]

Discusses key issues relevant to mobile-bearing total knee replacement. Reasons behind the clinical interest in mobile-bearing knees; Advantages of mobile-bearing knees over fixed-bearing total knee replacement; Theoretical significance to bone and joint surgery.

Background: Although the LCS (low contact stress) rotating-platform mobile-bearing knee replacement has been used extensively, there have been few intermediate or long-term clinical and radiographic follow-up studies evaluating the device. The purpose of this study was to report the nine to twelve-year results of a consecutive series of patients who had a primary total knee replacement performed with this device. Methods: Between November 1985 and November 1988, the senior author (R. C. J.) performed 119 consecutive total knee arthroplasties in eighty-six patients with LCS rotating-platform femoral and tibial components and a Townley all-polyethylene dome patellar component. All components were fixed with cement. The average age of the patients at the time of the operation was seventy years (range, thirty-seven to eightyeight years). Fifty-two patients (seventy-six knees) were female, and thirty-four patients (forty-three knees) were male. The patients were evaluated with clinical knee ratings and radiographic analysis nine to twelve years following the knee replacement. Results: At the time of the nine to twelve-year follow-up, sixty-four patients (eighty-six knees) were alive, eighteen patients (twenty-eight knees) had died, and four patients (five knees) had been lost to followup. Of the 114 knees in the eighty-two patients for whom the final outcome was known, none required a reoperation and none had a dislocation of the mobilebearing prosthesis. For the forty-five patients (sixty-six knees) who returned for final clinical and radiographic follow-up examinations at nine to twelve years, the average clinical and functional Knee Society ratings were 30 points (range, 2 to 70 points) and 44 points (range, 0 to 80 points) preoperatively and 90 points (range, 63 to 102 points) and 75 points (range, 30 to 100 points) at the final follow-up evaluation. The average Hospital for Special Surgery knee rating was 57 points (range, 28 to 80 points) preoperatively and 84... [ABSTRACT FROM AUTHOR]

Abstract: A number of investigators have demonstrated, in their hands, the potential for computer-assisted navigation to improve precision and accuracy in obtaining optimal knee alignment in the total knee arthroplasty construct. However, it will be difficult to demonstrate improvement in revision and loosening rates. In addition, there are concerns for computer glitches, training of personnel, extra time requirements, and cost and ability to demonstrate improvements in clinical results to warrant these concerns. Reproducibility of these improvements in precision and accuracy in the hands of the less experienced surgeon must be documented. [Copyright &y& Elsevier]

Presents the results of a study on the number of unicompartmental knee replacement surgeries performed between July 1975 and January 1982. Average patient age at surgery; Percentage of knees that were revised for loosening; Long-term durability of the treatment based on the study.

The development of patient profiles to subgroup individuals on a variety of variables has gained attention as a potential means to better inform clinical decision making. Patterns of pain sensitivity response specific to quantitative sensory testing (QST) modality have been demonstrated in healthy subjects. It has not been determined whether these patterns persist in a knee osteoarthritis population. In a sample of 218 participants, 19 QST measures along with pain, psychological factors, self-reported function, and quality of life were assessed before total knee arthroplasty. Component analysis was used to identify commonalities across the 19 QST assessments to produce standardized pain sensitivity factors. Cluster analysis then grouped individuals who exhibited similar patterns of standardized pain sensitivity component scores. The QST resulted in 4 pain sensitivity components: heat, punctate, temporal summation, and pressure. Cluster analysis resulted in 5 pain sensitivity profiles: a "low pressure pain" group, an "average pain" group, and 3 "high pain" sensitivity groups who were sensitive to different modalities (punctate, heat, and temporal summation). Pain and function differed between pain sensitivity profiles, along with sex distribution; however, no differences in osteoarthritis grade, medication use, or psychological traits were found. Residualizing QST data by age and sex resulted in similar components and pain sensitivity profiles. Furthermore, these profiles are surprisingly similar to those reported in healthy populations, which suggests that individual differences in pain sensitivity are a robust finding even in an older population with significant disease. [ABSTRACT FROM AUTHOR]

This study evaluated the efficacy of transcutaneous electrical nerve stimulation (TENS) in reducing pain and hyperalgesia and increasing function after total knee arthroplasty (TKA). We hypothesized that participants using TENS during rehabilitation exercises would report significantly lower pain during range-of-motion (ROM) activity and fast walking but not at rest, would have less hyperalgesia, and would have better function than participants receiving placebo-TENS or standard care. We also hypothesized that change in ROM pain would differ based on psychological characteristics (trait anxiety, pain catastrophizing, and depression) and treatment group. This prospective, randomized study used intent-to-treat analyses in 317 participants after primary, unilateral TKA. Assessors, blinded to treatment allocation, measured pain, function (ROM and gait speed), and hyperalgesia (quantitative sensory tests) postoperatively and 6 weeks after surgery. Analgesic intake, anxiety, depression, and pain catastrophizing were also assessed. TENS participants used it 1 to 2 times per day at 42 mA (on average) and had less pain postoperatively during active knee extension ( P = .019) and fast walking ( P = .006) than standard care participants. TENS and placebo-TENS were not significantly different. TENS participants who scored low on anxiety and pain catastrophizing had a greater reduction in ROM pain at 6 weeks than those who scored high on these factors ( P = .002 and P = .03). Both TENS and placebo-TENS participants had less postoperative mechanical hyperalgesia ( P = .03–.01) than standard care participants. Supplementing pharmacologic analgesia with TENS during rehabilitation exercises reduces movement pain postoperatively, but a placebo influence exists and the effect is gone by 6 weeks. Patients with low anxiety and pain catastrophizing may benefit most from TENS. [ABSTRACT FROM AUTHOR]