Abstract Periprosthetic joint infection (PJI) represents substantial clinical and economic burdens. This study evaluated patient and procedure characteristics and resource utilization associated with ...revision arthroplasty for PJI. The Nationwide Inpatient Sample (Q4 2005–2010) was analyzed for 235,857 revision THA (RTHA) and 301,718 revision TKA (RTKA) procedures. PJI was the most common indication for RTKA, and the third most common reason for RTHA. PJI was most commonly associated with major severity of illness (SOI) in RTHA, and with moderate SOI in RTKA. RTHA and RTKA for PJI had the longest length of stay. Costs were higher for RTHA/RTKA for PJI than for any other diagnosis except periprosthetic fracture. Epidemiologic differences exist in the rank, severity and populations for RTHA and RTKA for PJI.
Background
Revision THA and TKA are growing and important clinical and economic challenges. Healthcare systems tend to combine revision joint replacement procedures into a single service line, and ...differences between revision THA and revision TKA remain incompletely characterized. These differences carry implications for guiding care and resource allocation. We therefore evaluated epidemiologic trends associated with revision THAs and TKAs.
Questions/purposes
We sought to determine differences in (1) the number of patients undergoing revision TKA and THA and respective demographic trends; (2) differences in the indications for and types of revision TKA and THA; (3) differences in patient severity of illness scoring between THA and TKA; and (4) differences in resource utilization (including cost and length of stay LOS) between revision THA and TKA.
Methods
The Nationwide Inpatient Sample (NIS) was used to evaluate 235,857 revision THAs and 301,718 revision TKAs between October 1, 2005 and December 31, 2010. Patient characteristics, procedure information, and resource utilization were compared across revision THAs and TKAs. A revision burden (ratio of number of revisions to total number of revision and primary surgeries) was calculated for hip and knee procedures. Severity of illness scoring and cost calculations were derived from the NIS. As our study was principally descriptive, statistical analyses generally were not performed; however, owing to the large sample size available to us through this NIS analysis, even small observed differences presented are likely to be highly statistically significant.
Results
Revision TKAs increased by 39% (revision burden, 9.1%–9.6%) and THAs increased by 23% (revision burden, 15.4%–14.6%). Revision THAs were performed more often in older patients compared with revision TKAs. Periprosthetic joint infection (25%) and mechanical loosening (19%) were the most common reasons for revision TKA compared with dislocation (22%) and mechanical loosening (20%) for revision THA. Full (all-component) revision was more common in revision THAs (43%) than in TKAs (37%). Patients who underwent revision THA generally were sicker (> 50% major severity of illness score) than patients who underwent revision TKA (65% moderate severity of illness score). Mean LOS was longer for revision THAs than for TKAs. Mean hospitalization costs were slightly higher for revision THA (USD 24,697 +/− USD 40,489 SD) than revision TKA (USD 23,130 +/− USD 36,643 SD). Periprosthetic joint infection and periprosthetic fracture were associated with the greatest LOS and costs for revision THAs and TKAs.
Conclusions
These data could prove important for healthcare systems to appropriately allocate resources to hip and knee procedures: the revision burden for THA is 52% greater than for TKA, but revision TKAs are increasing at a faster rate. Likewise, the treating clinician should understand that while both revision THAs and TKAs bear significant clinical and economic costs, patients undergoing revision THA tend to be older, sicker, and have greater costs of care.
Prior studies comparing unicompartmental knee arthroplasty (UKA) with total knee arthroplasty (TKA) in the elderly are limited by heterogeneity in arthritic disease patterns and patient selection. We ...report the results of UKA and TKA in patients 75 years and older with isolated medial compartmental arthritis, with special emphasis on immediate postoperative recovery, complications, reoperation rates, and implant survivorship at midterm follow-up.
A retrospective review was performed of all patients 75 years and older who underwent UKA or TKA at our institution between 2002 and 2012. All TKA preoperative X-rays were reviewed by a blind observer to identify knees with isolated medial compartmental arthritis considered acceptable candidates for UKA. Patients with less than 2 years of follow-up, flexion contracture greater than 10°, and rheumatoid arthritis were excluded. The final sample included 120 UKA (106 patients) and 188 TKA (170 patients) procedures. Patient records were reviewed to determine early postoperative recovery, complications, reoperations for any reason, and implant survivorship.
UKA patients experienced significantly shorter operative time, shorter hospital stay, lower intraoperative estimated blood loss, lower postoperative transfusions, greater postoperative range of motion, and higher level of activity at time of discharge. Two UKA and 2 TKA patients required revision surgery. There was no statistically significant difference in postoperative Knee Society Scores. There were no differences in 5-year survivorship estimates.
Due to its less invasive nature, patients older than 75 undergoing UKA demonstrated faster initial recovery when compared to TKA, while maintaining comparable complications and midterm survivorship. UKA should be offered as an option in the elderly patient who fits the selection criteria for UKA.
Background
Morbid obesity and malnutrition are thought to be associated with more frequent perioperative complications after TKA. However, morbid obesity and malnutrition often are co-occurring ...conditions. Therefore it is important to understand whether morbid obesity, malnutrition, or both are independently associated with more frequent perioperative complications. In addition, assessing the magnitude of an increase in complications and whether these complications are major or minor is important for both conditions.
Questions/purposes
We asked: (1) Is morbid obesity independently associated with more frequent major perioperative complications after TKA? (2) Are major perioperative complications after TKA more prevalent among patients with a low serum albumin?
Methods
The National Surgical Quality Improvement Program (NSQIP) database was analyzed from 2006 to 2013. Patients were grouped as morbidly obese (BMI ≥ 40 kg/m
2
) or nonmorbidly obese (BMI ≥ 18.5 kg/m
2
to < 40 kg/m
2
), or by low serum albumin (serum albumin level < 3.5 mg/dL) or normal serum albumin (serum albumin level ≥ 3.5 mg/dL). The study cohort included 77,785 patients, including 35,573 patients with a serum albumin level of 3.5 g/dL or greater and 1570 patients with a serum albumin level less than 3.5 g/dL. Therefore, serum albumin levels were available for only 37,173 of the 77,785 of the patients (48%). There were 66,382 patients with a BMI between 18.5 kg/m
2
and 40 kg/m
2
and 11,403 patients with a BMI greater than 40 kg/m
2
. Data were recorded on patient mortality along with 21 complications reported in the NSQIP. We also developed three composite complication variables to represent risk of any infections, cardiac or pulmonary complications, and any major complications. For each complication, multivariate logistic regression analysis was performed. Independent variables included patient age, sex, race, BMI, American Society of Anesthesiologists classification, year of surgery, and Charlson comorbidity index score.
Results
Mortality was not increased in the morbidly obese group (0.14% vs 0.14%; p = 0.942). Patients who were morbidly obese were more likely to have progressive renal insufficiency (0.30% vs 0.10%; odds ratio OR, 2.47; 95% CI, 1.27–4.29; p < 0.001), superficial infection (1.07% vs 0.55%; OR, 1.87; 95% CI, 1.39–2.51; p < 0.001), and sepsis (0.36% vs 0.23%; OR, 1.70; 95% CI, 1.04–2.53; p = 0.034) compared with patients who were not morbidly obese. Patients who were morbidly obese were less likely to require blood transfusion (8.68% vs 12.06%; OR, 0.70; 95% CI, 0.63–0.77; p < 0.001) compared with patients who were not morbidly obese. Morbid obesity was not associated with any of the other 21 perioperative complications recorded in the NSQIP database. With respect to the composite complication variables, patients who were morbidly obese had an increased risk of any infection (3.31% vs 2.41%; OR, 1.38; 95% CI, 1.16–1.64; p < 0.001) but not for cardiopulmonary or any major complication. The group with low serum albumin had higher mortality than the group with normal serum albumin (0.64% vs 0.15%; OR, 3.17; 95% CI, 1.58–6.35; p = 0.001). Patients in the low serum albumin group were more likely to have a superficial surgical site infection (1.27% vs 0.64%; OR, 1.27; 95% CI, 1.09–2.75; p = 0.020); deep surgical site infection (0.38% vs 0.12%; OR, 3.64; 95% CI, 1.54–8.63; p = 0.003); organ space surgical site infection (0.45% vs 0.15%; OR, 2.71; 95% CI, 1.23–5.97; p = 0.013); pneumonia (1.21 vs 0.29%; OR, 3.55; 95% CI, 2.14–5.89; p < 0.001); require unplanned intubation (0.51% vs 0.17%, OR, 2.24; 95% CI, 1.07–4.69; p = 0.033); and remain on a ventilator more than 48 hours (0.38% vs 0.07%; OR, 4.03; 95% CI, 1.64–9.90; p = 0.002). They are more likely to have progressive renal insufficiency (0.45 % vs 0.12%; OR, 2.71; 95% CI, 1.21–6.07; p = 0.015); acute renal failure (0.32% vs 0.06%; OR, 5.19; 95% CI, 1.96–13.73; p = 0.001); cardiac arrest requiring cardiopulmonary resuscitation (0.19 % vs 0.12%; OR, 3.74; 95% CI, 1.50–9.28; p = 0.005); and septic shock (0.38% vs 0.08%; OR, 4.4; 95% CI, 1.74–11.09; p = 0.002). Patients in the low serum albumin group also were more likely to require blood transfusion (17.8% vs 12.4%; OR, 1.56; 95% CI, 1.35–1.81; p < 0.001). In addition, among the three composite complication variables, any infection (5.0% vs 2.4%; OR, 2.0; 95% CI, 1.53–2.61; p < 0.001) and any major complication (2.4% vs 1.3%; OR, 1.41; 95% CI, 1.00–1.97; p = 0.050) were more prevalent among the patients with low serum albumin. There was no difference for cardiopulmonary complications.
Conclusions
Morbid obesity is not independently associated with the majority of perioperative complications measured by the NSQIP and was associated only with increases in progressive renal insufficiency, superficial surgical site infection, and sepsis among the 21 perioperative variables measured. However, low serum albumin was associated with increased mortality and multiple additional major perioperative complications after TKA. Low serum albumin, more so than morbid obesity, is associated with major perioperative complications. This is an important finding, as low serum albumin may be more modifiable than morbid obesity in patients who are immobile or have advanced knee osteoarthritis.
Level of Evidence
Level III, prognostic study.
Severe metaphyseal and meta-diaphyseal bone loss poses important challenges in revision total knee arthroplasty. The best strategy for addressing massive tibial bone loss has not been determined. The ...purpose of this study was to assess the intermediate-term clinical and radiographic results of porous tibial cone implantation.
Sixty-six porous tantalum tibial cones (sixty-three patients) were reviewed at a mean follow-up time of seventy months (range, sixty to 106 months). According to the Anderson Orthopaedic Research Institute bone defect classification, twenty-four knees had a Type-3 defect, twenty-five knees had a Type-2B defect, and seventeen knees had a Type-2A defect.
The mean age at the time of the index revision was sixty-seven years (range, forty-one to eighty-three years), and 57% of patients were female. The mean American Society of Anesthesiologists Physical Status was 2.4 (range, 2 to 3), and the mean body mass index was 33 kg/m(2) (range, 25 to 53 kg/m(2)). Fifteen patients (24%) were on immunosuppressant medications, and eight patients (13%) were current smokers. The patients underwent a mean number of 3.4 prior knee surgical procedures (range, one to twenty procedures), and 49% of patients (thirty-one patients) had a history of periprosthetic infection. The mean Knee Society Scores improved significantly from 55 points preoperatively (range, 4 to 97 points) to 80 points (range, 28 to 100 points) at the time of the latest follow-up (p < 0.0001). One patient had progressive radiolucencies about the tibial stem and cone on radiographs. One patient had complete radiolucencies about the tibial cone, concerning for fibrous ingrowth. Three other cones were revised: one for infection, one for aseptic loosening, and one for periprosthetic fracture. Revision-free survival of the tibial cone component was >95% at the time of the latest follow-up.
Porous tantalum tibial cones offer a promising management option for severe tibial bone loss. At the intermediate-term follow-up (five to nine years), porous tantalum tibial cones had durable clinical results and radiographic fixation. The biologic ingrowth of these implants offers the potential for successful long-term structural support in complex knee reconstruction.
High body mass index (BMI) is associated with increased rates of complications after total knee arthroplasty. To date, to our knowledge, studies have examined risk as a dichotomous variable using ...specific BMI thresholds. The purpose of this investigation was to quantify implant survival and the risk of common complications after total knee arthroplasty using BMI as a continuous variable.
Using prospectively collected data from our institutional total joint registry, we analyzed 22,289 consecutive knees, in 16,136 patients, treated with primary total knee arthroplasty from 1985 to 2012. The mean BMI of these patients at the time of the surgical procedure was 31.3 kg/m (range, 11 to 69 kg/m). The Kaplan-Meier survival method was used to estimate survivorship, reoperations, and common complications, with associations of outcomes assessed using a Cox regression model.
Utilizing smoothing spline parameterization, we found that reoperation (p < 0.001) and implant revision or removal rates (p < 0.001) increased with increasing BMI after total knee arthroplasty. Increasing BMI also was associated with increased rates of wound infection (hazard ratio HR, 1.07; p < 0.001) and deep infection (HR, 1.08; p < 0.001) per unit of BMI over 35 kg/m. A BMI of 35 to 40 kg/m was associated with a higher rate of implant revision for aseptic loosening (p < 0.001) and for polyethylene wear (p < 0.001) compared with a BMI of 18 to 24.99 kg/m. There was no correlation between BMI and risk of venous thromboembolism, tibiofemoral instability, or need for knee manipulation.
The rates of reoperation, implant revision or removal, and many common complications after total knee arthroplasty were strongly associated with BMI.
Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Background and purpose — Systematic comparisons of anterior approach (A) versus posterior approach (P) in primary total hip arthroplasty (THA) have largely focused on perioperative outcomes. In this ...systematic review with meta-analysis, we compared complication risk of A versus P in studies of primary THA with at least 1-year mean follow-up. Patients and methods — We performed a systematic review of prospective and retrospective studies with at least 1-year mean follow-up that reported complications of A and P primary THA. Complications included infection, dislocation, reoperation, thromboembolic event, heterotopic ossification, wound complication, fracture, and nerve injury. Random effects meta-analysis was used for all outcomes. Complication risk was reported as rate ratio (RR) to account for differential follow-up durations; values >1 indicated higher complication risk with A and values <1 indicated lower risk with A. Results — 19 studies were included; 15 single-center comparative studies with 6,620 patients (2,278 A; 4,342 P) and 4 multicenter registries with 157,687 patients (18,735 A; 138,952 P). Median follow-up was 16 (12–64) months) with A and 18 (12–110) months with P. Anterior approach was associated with lower rate of infection (RR =0.55, p = 0.002), dislocation (RR =0.65, p = 0.03), and reoperation (RR =0.84, p < 0.001). No statistically significant differences were observed in rate of thromboembolic event (RR =0.59, p = 0.5), heterotopic ossification (RR =0.63, p = 0.1), wound complication (RR =0.93, p = 0.8), or fracture (RR =1.0, p = 0.9). There was a higher rate of patient-reported nerve injury with A (RR =2.3, p = 0.01). Interpretation — Comparing A with P in primary THA, A was associated with lower risk of reoperation, dislocation, and infection, but higher risk of patient-reported nerve injury.
The choice between anterior approach (AA) and posterior approach (PA) in primary total hip arthroplasty (THA) is controversial. Previous reviews have predominantly relied on data from retrospective ...studies.
This systematic review included prospective studies comparing postoperative outcomes through 90 days of AA vs PA in primary THA. Outcomes were pain severity, narcotic usage, hip function using Harris Hip Score, and complications. Random effects meta-analysis was performed for all outcomes. Efficacy data were reported as standardized mean difference (SMD) where values of 0.2, 0.5, 0.8, and 1.0 were defined as small, medium, large, and very large effect sizes, respectively. Complications were reported as the absolute risk difference (RD) where a positive value implied higher risk with AA and a lower value implied lower risk with AA.
A total of 13 prospective comparative studies (7 randomized) with patients treated with AA (n = 524) or PA (n = 520) were included. The AA was associated with lower pain severity (SMD = −0.37, P < .001), lower narcotic usage (SMD = −0.36, P = .002), and improved hip function (SMD = 0.31, P = .002) compared to PA. No differences between surgical approaches were observed for dislocation (RD = 0.2%, P = .87), fracture (RD = 0.2%, P = .87), hematoma (RD = 0%, P = .99), infection (RD = 0.2%, P = .85), thromboembolic event (RD = −0.9%, P = .42), or reoperation (RD = 1.3%, P = .26). Conclusions of this study were unchanged when subjected to sensitivity analyses.
In this systematic review and meta-analysis of prospective studies comparing postoperative outcomes through 90 days of AA vs PA in primary THA, patients treated with AA reported less pain, consumed fewer narcotics, and reported better hip function. No statistical differences in complication rates were detected between AA and PA. Ultimately, the choice of surgical approach in primary THA should consider preference and experience of the surgeon as well as preference and anatomy of the patient.
A lack of racial and ethnic representation in clinical trials may limit the generalizability of the orthopaedic evidence base as it applies to patients in underrepresented minority populations and ...perpetuate existing disparities in use, complications, or functional outcomes. Although some commentators have implied the need for mandatory race or ethnicity reporting across all orthopaedic trials, the usefulness of race or ethnic reporting likely depends on the specific topic, prior evidence of disparities, and individualized study hypotheses.
In a systematic review, we asked: (1) What proportion of orthopaedic clinical trials report race or ethnicity data, and of studies that do, how many report data regarding social covariates or genomic testing? (2) What trends and associations exist for racial and ethnic reporting among these trials between 2000 and 2020? (3) What is the racial or ethnic representation of United States trial participants compared with that reported in the United States Census?
We performed a systematic review of randomized controlled trials with human participants published in three leading general-interest orthopaedic journals that focus on clinical research: The Journal of Bone and Joint Surgery, American Volume; Clinical Orthopaedics and Related Research; and Osteoarthritis and Cartilage. We searched the PubMed and Embase databases using the following inclusion criteria: English-language studies, human studies, randomized controlled trials, publication date from 2000 to 2020, and published in Clinical Orthopaedics and Related Research; The Journal of Bone and Joint Surgery, American Volume; or Osteoarthritis and Cartilage. Primary outcome measures included whether studies reported participant race or ethnicity, other social covariates (insurance status, housing or homelessness, education and literacy, transportation, income and employment, and food security and nutrition), and genomic testing. The secondary outcome measure was the racial and ethnic categorical distribution of the trial participants included in the studies reporting race or ethnicity. From our search, 1043 randomized controlled trials with 184,643 enrolled patients met the inclusion criteria. Among these studies, 21% (223 of 1043) had a small (< 50) sample size, 56% (581 of 1043) had a medium (50 to 200) sample size, and 23% (239 of 1043) had a large (> 200) sample size. Fourteen percent (141 of 1043) were based in the Northeast United States, 9.2% (96 of 1043) were in the Midwest, 4.7% (49 of 1043) were in the West, 7.2% (75 of 1043) were in the South, and 65% (682 of 1043) were outside the United States. We calculated the overall proportion of studies meeting the inclusion criteria that reported race or ethnicity. Then among the subset of studies reporting race or ethnicity, we determined the overall rate and distribution of social covariates and genomic testing reporting. We calculated the proportion of studies reporting race or ethnicity that also reported a difference in outcome by race or ethnicity. We calculated the proportion of studies reporting race or ethnicity by each year in the study period. We also calculated the proportions and 95% CIs of individual patients in each racial or ethnic category of the studies meeting the inclusion criteria.
During the study period (2000 to 2020), 8.5% (89 of 1043) of studies reported race or ethnicity. Of the trials reporting this factor, 4.5% (four of 89) reported insurance status, 15% (13 of 89) reported income, 4.5% (four of 89) reported housing or homelessness, 18% (16 of 89) reported education and literacy, 0% (0 of 89) reported transportation, and 2.2% (two of 89) reported food security or nutrition of trial participants. Seventy-eight percent (69 of 89) of trials reported no social covariates, while 22% (20 of 89) reported at least one. However, 0% (0 of 89) of trials reported genomic testing. Additionally, 5.6% (five of 89) of these trials reported a difference in outcomes by race or ethnicity. The proportion of studies reporting race or ethnicity increased, on average, by 0.6% annually (95% CI 0.2% to 1.0%; p = 0.02). After controlling for potentially confounding variables such as funding source, we found that studies with an increased sample size were more likely to report data by race or ethnicity; location in North America overall, Europe, Asia, and Australia or New Zealand (compared with the Northeast United States) were less likely to; and specialty-topic studies (compared with general orthopaedics research) were less likely to. Our sample of United States trials contained 18.9% more white participants than that reported in the United States Census (95% CI 18.4% to 19.4%; p < 0.001), 5.0% fewer Black participants (95% CI 4.6% to 5.3%; p < 0.001), 17.0% fewer Hispanic participants (95% CI 16.8% to 17.1%; p < 0.001), 5.3% fewer Asian participants (95% CI 5.2% to 5.4%; p < 0.001), and 7.5% more participants from other groups (95% CI 7.2% to 7.9%; p < 0.001).
Reporting of race or ethnicity data in orthopaedic clinical trials is low compared with other medical fields, although the proportion of diseases warranting this reporting might be lower in orthopaedics.
Investigators should initiate discussions about race and ethnicity reporting in the early stages of clinical trial development by surveying available published evidence for relevant health disparities, social determinants, and, when warranted, genomic risk factors. The decision to include or exclude race and ethnicity data in study protocols should be based on specific hypotheses, necessary statistical power, and an appreciation for unmeasured confounding. Future studies should evaluate cost-efficient mechanisms for obtaining baseline social covariate data and investigate researcher perspectives on current administrative workflows and decision-making algorithms for race and ethnicity reporting.
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