Search

ObjectivesGenerating and using real-world evidence (RWE) is a pragmatic solution for evaluating health technologies. RWE is recognized by regulators, health technology assessors, clinicians, and manufacturers as a valid source of information to support their decision-making. Well-designed registries can provide RWE and become more powerful when linked with electronic health records and administrative databases in coordinated registry networks (CRNs). Our objective was to create a framework of maturity of CRNs and registries, so guiding their development and the prioritization of funding.Design setting and participantsWe invited 52 stakeholders from diverse backgrounds including patient advocacy groups, academic, clinical, industry and regulatory experts to participate on a Delphi survey. Of those invited, 42 participated in the survey to provide feedback on the maturity framework for CRNs and registries. An expert panel reviewed the responses to refine the framework until the target consensus of 80% was reached. Two rounds of the Delphi were distributed via Qualtrics online platform from July to August 2020 and from October to November 2020.Main outcome measuresConsensus on the maturity framework for CRNs and registries consisted of seven domains (unique device identification, efficient data collection, data quality, product life cycle approach, governance and sustainability, quality improvement, and patient-reported outcomes), each presented with five levels of maturity.ResultsOf 52 invited experts, 41 (79.9%) responded to round 1; all 41 responded to round 2; and consensus was reached for most domains. The expert panel resolved the disagreements and final consensus estimates ranged from 80.5% to 92.7% for seven domains.ConclusionsWe have developed a robust framework to assess the maturity of any CRN (or registry) to provide reliable RWE. This framework will promote harmonization of approaches to RWE generation across different disciplines and health systems. The domains and their levels may evolve over time as new solutions become available.

Background: For the vast majority of displaced femoral neck fractures in older patients, cemented femoral fixation is indicated because it is associated with a lower risk of periprosthetic fracture than cementless fixation. Nevertheless, cementless fixation continues to be utilized with high frequency for hip fractures in the United States. It is therefore helpful to understand the performance of individual cementless brands and models. Although prior studies have compared femoral stems by design type or stem geometry, there may still be a difference in revision risk according to femoral stem brand given the potential differences within design groupings with regard to manufacturing, implantation systems, and implant design nuances among vendors. Questions/purposes: (1) Is there a difference in aseptic revision risk among femoral stem brands in patients ≥ 60 years of age who have displaced femoral neck fractures treated with cementless hemiarthroplasty? (2) Is there a difference in revision for periprosthetic fracture among femoral stem brands in patients ≥ 60 years of age with displaced femoral neck fractures treated with cementless hemiarthroplasty? Methods: A retrospective, comparative, large-database cohort study was conducted using data from Kaiser Permanente's Hip Fracture Registry. This integrated healthcare system covers more than 12 million members throughout eight regions in the United States; membership has been found to be representative of the general population in the areas served. The Hip Fracture Registry collects details on all patients who undergo hip fracture repair within the organization. These patients are then longitudinally monitored for outcomes after their repair, and all identified outcomes are manually validated through chart review. Patients ages ≥ 60 years who underwent unilateral hemiarthroplasty treatment of a displaced femoral neck fracture from 2009 to 2021 were identified (n = 22,248). Hemiarthroplasties for polytrauma, pathologic or open fractures, or patients who had additional surgeries at other body sites during the same stay, as well as those with prior procedures in the same hip, were excluded (21.4% [4768]). Cemented procedures and those with missing or inconsistent implant information (for example, cement used but cementless implant recorded) were further excluded (47.1% [10,485]). To allow for enough events for evaluation, the study sample was restricted to seven stems for which there were at least 300 hemiarthroplasties performed, including four models from DePuy Synthes (Corail®, Summit®, Summit Basic, and Tri-Lock®) and three from Zimmer Biomet (Medial-Lateral [M/L] Taper®, Trabecular Metal®, and Versys® Low Demand Fracture [LD/FX]). The final sample included 5676 cementless hemiarthroplasties: 653 Corail, 402 M/L Taper, 1699 Summit, 1590 Summit Basic, 384 Tri-Lock, 637 Trabecular Metal, and 311 Versys LD/FX. Procedures were performed by 396 surgeons at 35 hospitals. The mean age and BMI for the cohort was 81 years and 24 kg/m2, respectively; most were women (66% [3733 of 5676]) and White (79% [4488 of 5676]). Based on standardized mean differences, we controlled for age, race/ethnicity, American Society of Anesthesiologist (ASA) classification, anesthesia technique, operative year, average annual surgeon hemiarthroplasty volume, and operative year across the seven stem groups. Of the 5676 patients, 7% (378 of 5676) were lost to follow-up through membership termination at a median time of 1.6 years, and 56% (3194 of 5676) of the patients died during study follow-up. A multivariable cause-specific Cox proportional hazards regression model was used to evaluate the risk for aseptic revision with adjustment for age, gender, ASA classification, depression, operating surgeon, deficiency anemias, time from admission to surgery, and average annual surgeon hemiarthroplasty volume. A random intercept was included to address effects from hemiarthroplasties performed by the same surgeon. Risk for revision for periprosthetic fracture was also evaluated as a secondary outcome. Results: In the adjusted analysis, the Summit Basic (HR 1.91 [95% confidence interval 1.34 to 2.72]; p < 0.001), the M/L Taper (HR 1.91 [95% CI 1.15 to 3.15]; p = 0.01), and the Versys LD/FX (HR 2.12 [95% CI 1.25 to 3.61]; p = 0.005) had higher aseptic revision risks during follow-up when compared with the Summit. No differences were observed for the Corail (HR 0.57 [95% CI 0.29 to 1.10]; p = 0.09), the Tri-Lock (HR 1.13 [95% CI 0.62 to 2.07]; p = 0.68), or the Trabecular Metal (HR 1.14 [95% CI 0.69 to 1.89]; p = 0.61) compared with the Summit. A higher risk for revision because of periprosthetic fracture was observed with the M/L Taper (HR 2.43 [95% CI 1.29 to 4.58]; p = 0.006) and the Summit Basic (within 3 months of follow-up: HR 1.16 [95% CI 0.60 to 2.25]; p = 0.66; after 3 months of follow-up: HR 2.84 [95% CI 1.36 to 5.94]; p = 0.006) stems when compared with the Summit. Conclusion: In a cohort of 5676 cementless hemiarthroplasties, we found differences in revision risks among different femoral stem brands. Based on our findings, we recommend against utilization of the Zimmer M/L Taper, DePuy Summit Basic, and Zimmer Versys LD/FX in the treatment of displaced geriatric femoral neck fractures with cementless hemiarthroplasty. Future large registry studies are needed to further elucidate differences in aseptic revision risk among higher performing cementless femoral stems. Although cemented fixation remains the recommended approach based on the best available evidence in hemiarthroplasty treatment of hip fractures, our findings may help to mitigate aseptic revision risk should cementless fixation be chosen. Level of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Although the majority of intertrochanteric femoral fractures in the United States are now treated with cephalomedullary nailing, it remains uncertain whether differences in clinical performance by nail type exist. The purpose of this study was to compare the aseptic revision rates associated with the 3 most commonly utilized cephalomedullary nails in the United States today: the Gamma nail (Stryker), the INTERTAN (Smith+Nephew), and the Trochanteric Fixation Nail/Trochanteric Fixation Nail Advanced (TFN/TFNA; DePuy Synthes). Methods: Using an integrated health-care system's hip fracture registry, patients ≥60 years of age who were treated with 1 of these 3 commonly used cephalomedullary nail devices were identified. Potential confounders were identified and controlled for, including age, gender, race or ethnicity, body mass index, smoking status, American Society of Anesthesiologists classification, anesthesia type, Elixhauser comorbidities, and the operating surgeon. Multivariable Cox proportional-hazards regression was used to evaluate the risk of aseptic revision (the primary outcome measure) by cephalomedullary nail type, with mortality and revisions unrelated to the index fracture considered as competing events. Results: There were 19,215 patients included in the study sample (71.4% female, 77.0% White), including 4,421 in the Gamma nail group, 2,350 in the INTERTAN nail group, and 12,444 in the TFN/TFNA nail group. In the multivariable analysis involving nails of all lengths, the INTERTAN group was found to have a higher risk of aseptic revision compared with the TFN/TFNA group (8-year crude revision rate, 2.9% compared with 1.8%; hazard ratio [HR], 1.62 [95% confidence interval (CI), 1.15 to 2.27]; p = 0.006). The increased risk associated with the INTERTAN nail was primarily seen among the long nails (HR, 1.83 [95% CI, 1.16 to 2.87]; p = 0.009) rather than the short nails (HR, 1.36 [95% CI, 0.87 to 2.11]; p = 0.18). There were no differences in aseptic revision observed between the Gamma group and the TFN/TFNA group. Conclusions: In this study of 19,215 patients with a hip fracture treated with cephalomedullary nailing, the INTERTAN nail was found to have a significantly higher risk of aseptic revision. Further research is required to determine whether these results could be related to the unique design of this implant. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

BackgroundThe most common bearing surface used among primary THAs worldwide is a metal or ceramic femoral head that articulates against a highly crosslinked ultrahigh-molecular-weight polyethylene (HXLPE) acetabular liner. Despite their widespread use, relatively little is known about the comparative effectiveness of ceramic versus metal femoral heads with respect to risk of revision and dislocation as well as the role of head size in this relationship.Questions/purposesThe purpose of this study was to evaluate the risk of (1) all-cause revision in metal versus ceramic femoral heads when used with an HXLPE liner, including an evaluation of the effect of head size; and (2) dislocation in metal versus ceramic femoral heads when used with an HXLPE liner as well as an assessment of the effect of head size.MethodsData were collected as part of the Kaiser Permanente Total Joint Replacement Registry between 2001 and 2013. Patients in this study were on average overweight (body mass index = 29 kg/m2), 67 years old, mostly female (57%), and had osteoarthritis (93%) as the primary indication for surgery. The material of the femoral head (metal, ceramic) was crossed with head size (< 32, 32, 36, > 36 mm), yielding eight device groupings. Only uncemented devices were evaluated. The primary outcome was all-cause revision (n = 28,772) and the secondary outcome was dislocation within 1 year (n = 19,623). Propensity scores were used to adjust for potential confounding at the implant/patient level using between-within semiparametric survival models that control for surgeon and hospital confounding and adjust estimates for the within-cluster correlation among observations on the response.ResultsFor all-cause revision, there was no difference between ceramic versus metal (reference) heads in combination with an HXLPE liner (hazard ratio [HR] = 0.82 [0.65-1.04], p = 0.099). Smaller metal head sizes of < 32 mm were associated with increased risk of revision relative to 36 mm (HR = 1.66 [1.20-2.31], p = 0.002, adjusted p = 0.025). For dislocation, ceramic heads increased risk relative to metal at < 32 mm only (HR = 4.39 [1.72-11.19], p = 0.002, adjusted p = 0.020). Head sizes < 32 mm were associated with increased risk of dislocation relative to 36 mm for metal (HR = 2.99 [1.40-6.39], p = 0.005, adjusted p = 0.047) and ceramic heads (HR = 15.69 [6.07-40.55], p < 0.001, adjusted p < 0.001).ConclusionsThe results did not provide evidence for use of one femoral head material over another when used with HXLPE liners for the outcome of revision, but for dislocation, metal performed better than ceramic with < 32-mm heads. Overall, the findings suggest increased risk of revision/dislocation with head sizes < 32 mm.Level of evidenceLevel III, therapeutic study.

Background and purposeAseptic revisions comprise 80% of revision total knee arthroplasties (TKAs). We determined the incidence of re-revision TKA, the reasons for re-revision, and risk factors associated with these procedures.Patients and methodsWe conducted a retrospective cohort study of 1,154 patients who underwent aseptic revision TKA between 2002 and 2013 and were followed prospectively by a total joint replacement registry in the USA. Revision was defined as any operation in which an implanted component was replaced. Patient-, surgeon-, and procedure-related risk factors were evaluated. Survival analyses were conducted.ResultsThere were 114 re-revisions (10%) with a median time to reoperation of 3.6 years (interquartile range (IQR): 2.6-5.2). The infection rate was 2.9% (34/1,154) and accounted for 30% of re-revisions (34 of 114). In adjusted models, use of antibiotic-loaded cement was associated with a 50% lower risk of all-cause re-revision surgery (hazard ratio (HR) = 0.5, 95% CI: 0.3-0.9), age with a 20% lower risk for every 10-year increase (HR = 0.8, CI: 0.7-1.0), body mass index (BMI) with a 20% lower risk for every 5-unit increase (HR = 0.8, CI: 0.7-1.0), and a surgeon's greater cumulative experience (≥ 20 cases vs.

BackgroundTotal hip arthroplasty (THA) is often performed in patients who are older and may take bisphosphonates to treat a variety of conditions, most commonly osteoporosis. However, the clinical effects of bisphosphonate use on patients who have undergone THA are not well described.Questions/purposes(1) Is bisphosphonate use in patients with osteoarthritis undergoing primary THA associated with a change in the risk of all-cause revision, aseptic revision, or periprosthetic fracture compared with patients not treated with bisphosphonates? (2) Does the risk of bisphosphonate use and revision and periprosthetic fracture vary by patient bone mineral density and age?MethodsA retrospective cohort study of 12,878 THA recipients for the diagnosis of osteoarthritis was conducted; 17.8% of patients were bisphosphonate users. Data sources for this study included a joint replacement registry (93% voluntary participation) and electronic health records and an osteoporosis screening database with complete capture of cases as part of the Kaiser Permanente integrated healthcare system. The endpoints for this study were revision surgery for any cause, aseptic revision, and periprosthetic fracture. The exposure of interest was bisphosphonate use; patients were considered users if prescriptions were continuously refilled for a period equal to or longer than 6 months. Bone quality (based on dual-energy x-ray absorptiometery ordered based on the National Osteoporosis Foundation's clinical guidelines taken within 5 years of the THA) and patient age (< 65 versus ≥ 65 years) were evaluated as effect modifiers. Patient, surgeon, and hospital factors were evaluated as confounders. Cox proportional hazards models were used. Hazard ratios (HRs) and 95% confidence intervals (CIs) were determined.ResultsAge- and sex-adjusted risks of all-cause (HR, 0.50; 95% CI, 0.33-0.74; p < 0.001) and aseptic revision (HR, 0.53; 95% CI, 0.34-0.81; p = 0.004) was lower in bisphosphonate users than in nonusers. The adjusted risk of periprosthetic fractures in patients on bisphosphonates was higher than in patients not on bisphosphonates (HR, 1.92; 95% CI, 1.13-3.27; p = 0.016). Lower risks of all-cause revision and aseptic revision were observed in patients with osteopenia (HR, 0.49; 95% CI, 0.29-0.84; and HR, 0.53; 95% CI, 0.29-0.99, respectively) and osteoporosis (HR, 0.22; 95% CI, 0.08-0.62; and HR, 0.33; 95% CI, 0.11-0.99, respectively).ConclusionsPatients considered bisphosphonate users who underwent THA had a lower risk for revision surgery. Bisphosphonate use was associated with a higher risk of periprosthetic fractures in younger patients with normal bone quantity. Evaluation of bone quality and bisphosphonate use for the diagnosis of osteoporosis is encouraged in patients with osteoarthritis who are candidates for primary THA. Further research is required to determine the optimal duration of therapy because long-term bisphosphonate use has been associated with atypical femur fractures.Level of evidenceLevel III, therapeutic study.

BackgroundAlthough total hip arthroplasty (THA) is a successful procedure, 4% to 11% of patients who undergo THA are readmitted to the hospital. Prior studies have reported rates and risk factors of THA readmission but have been limited to single-center samples, administrative claims data, or Medicare patients. As a result, hospital readmission risk factors for a large proportion of patients undergoing THA are not fully understood.Questions/purposes(1) What is the incidence of hospital readmissions after primary THA and the reasons for readmission? (2) What are the risk factors for hospital readmissions in a large, integrated healthcare system using current perioperative care protocols?MethodsThe Kaiser Permanente (KP) Total Joint Replacement Registry (TJRR) was used to identify all patients with primary unilateral THAs registered between January 1, 2009, and December 31, 2011. The KPTJRR's voluntary participation is 95%. A logistic regression model was used to study the relationship of risk factors (including patient, clinical, and system-related) and the likelihood of 30-day readmission. Readmissions were identified using electronic health and claims records to capture readmissions within and outside the system. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated. Of the 12,030 patients undergoing primary THAs included in the study, 59% (n = 7093) were women and average patient age was 66.5 years (± 10.7).ResultsThere were 436 (3.6%) patients with hospital readmissions within 30 days of the index procedure. The most common reasons for readmission were infection and inflammatory reaction resulting from internal joint prosthetic (International Classification of Diseases, 9(th) Revision, Clinical Modification [ICD-9-CM] 996.66, 7.0%); other postoperative infection (ICD-9-CM 998:59, 5.5%); unspecified septicemia (ICD-9-CM 038.9, 4.9%); and dislocation of a prosthetic joint (ICD-9-CM 996.42, 4.7%). In adjusted models, the following factors were associated with an increased likelihood of 30-day readmission: medical complications (OR, 2.80; 95% CI, 1.59-4.93); discharge to facilities other than home (OR, 1.89; 95% CI, 1.39-2.58); length of stay of 5 or more days (OR, 1.80; 95% CI, 1.22-2.65) versus 3 days; morbid obesity (OR, 1.74; 95% CI, 1.25-2.43); surgeries performed by high-volume surgeons compared with medium volume (OR, 1.53; 95% CI, 1.14-2.08); procedures at lower-volume (OR, 1.41; 95% CI, 1.07-1.85) and medium-volume hospitals (OR, 1.81; 95% CI, 1.20-2.72) compared with high-volume ones; sex (men: OR, 1.51; 95% CI, 1.18-1.92); obesity (OR, 1.32; 95% CI, 1.02-1.72); race (black: OR, 1.26; 95% CI, 1.02-1.57); increasing age (OR, 1.03; 95% CI, 1.01-1.04); and certain comorbidities (pulmonary circulation disease, chronic pulmonary disease, hypothyroidism, and psychoses).ConclusionsThe 30-day hospital readmission rate after primary THA was 3.6%. Modifiable factors, including obesity, comorbidities, medical complications, and system-related factors (hospital), have the potential to be addressed by improving the health of patients before this elective procedure, patient and family education and planning, and with the development of high-volume centers of excellence. Nonmodifiable factors such as age, sex, and race can be used to establish patient and family expectations regarding risk of readmission after THA. Contrary to other studies and the finding of increased hospital volume associated with lower risk of readmission, higher volume surgeons had a higher risk of patient readmission, which may be attributable to the referral patterns in our organization.Level of evidenceLevel III, therapeutic study.

BackgroundThe survivorship of implants after revision total hip arthroplasty and risk factors associated with re-revision are not well defined. We evaluated the re-revision rate with use of the institutional total joint replacement registry. The purpose of this study was to determine patient, implant, and surgeon factors associated with re-revision total hip arthroplasty.MethodsA retrospective cohort study was conducted. The total joint replacement registry was used to identify patients who had undergone revision total hip arthroplasty for aseptic reasons from April 1, 2001, to December 31, 2010. The end point of interest was re-revision total hip arthroplasty. Risk factors evaluated for re-revision total hip arthroplasty included: patient risk factors (age, sex, body mass index, race, and general health status), implant risk factors (fixation type, bearing surface, femoral head size, and component replacement), and surgeon risk factors (volume and experience). A multivariable Cox proportional hazards model was used.ResultsSix hundred and twenty-nine revision total hip arthroplasties with sixty-three (10%) re-revisions were evaluated. The mean cohort age (and standard deviation) was 57.0 ± 12.4 years, the mean body mass index (and standard deviation) was 29.5 ± 6.1 kg/m(2), and most of the patients were women (64.5%) and white (81.9%) and had an American Society of Anesthesiologists score of

We examined the assumption that patients undergoing same-day bilateral total knee arthroplasty (TKA) have a higher incidence of major peri-operative complications than patients who stage their procedures over the course of a year. Between April 2001 and March 2007, prospective data were collected using a total joint registry. Patients undergoing primary, bilateral, same-day, TKAs were compared to patients undergoing primary, staged, bilateral TKAs within 12 months of the index operation. A total of 2441 TKAs were performed on the same day, while 4231 were staged. There were no significant differences in 90-day mortality, thrombotic events and infections between the two groups. Performing same-day bilateral TKA does not predispose patients to increased cumulative incidence of major complications over staged arthroplasty.

Background: The reported incidence of posttraumatic knee osteoarthritis (PTOA) after primary anterior cruciate ligament reconstruction (ACLR) varies considerably. Further, there are gaps in identifying which patients are at risk for PTOA after ACLR and whether there are modifiable factors. Purpose: To (1) determine the incidence of PTOA in a primary ACLR cohort and (2) identify patient and perioperative factors associated with the development of PTOA after primary ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: Data from the Kaiser Permanente ACLR Registry were used to conduct a cohort study. Patients who had undergone primary ACLR without a previous diagnosis of osteoarthritis were identified (2009-2020). The crude incidence of PTOA was calculated using the Aalen-Johansen estimator with a multistate model. The association of patient and operative factors with the development of PTOA after primary ACLR was modeled as a time to event using multistate Cox proportional hazards regression. Models stratified by age (<22 and ≥22 years) were also conducted because of the effect modification of age. Results: The study sample included 41,976 cases of primary ACLR. The incidence of PTOA was 1.7%, 5.1%, and 13.6% at 2, 5, and 10 year follow-ups, respectively. Risk factors for PTOA that were consistently identified in the overall cohort and age-stratified groups included a body mass index ≥30 versus <30 and an allograft or quadriceps tendon autograft versus a hamstring tendon autograft. Patients presenting with knee pain after ACLR were further identified when considering postoperative factors. Other risk factors for PTOA in the overall cohort included age ≥22 versus <22 years, bone–patellar tendon–bone autograft versus hamstring tendon autograft, hypertension, cartilage injury, meniscal injury, revision after primary ACLR with concomitant meniscal/cartilage surgery, multiligament injury, other activity at the time of injury compared with sport, and tibial tunnel drilling technique rather than the anteromedial portal. Conclusion: Knee pain after ACLR may be an early sign of PTOA. Surgeons should consider the adverse associations of a higher body mass index and an allograft or quadriceps tendon autograft with the development of PTOA, as these were factors identified with a higher risk, regardless of a patient's age at the time of primary ACLR. [ABSTRACT FROM AUTHOR]

BackgroundPoor glycemic control in patients with diabetes may be associated with adverse surgical outcomes. We sought to determine the association of diabetes status and preoperative glycemic control with several surgical outcomes, including revision arthroplasty and deep infection.MethodsWe conducted a retrospective cohort study in five regions of a large integrated health-care organization. Eligible subjects, identified from the Kaiser Permanente Total Joint Replacement Registry, underwent an elective first primary total knee arthroplasty during 2001 through 2009. Data on demographics, diabetes status, preoperative hemoglobin A1c (HbA1c) level, and comorbid conditions were obtained from electronic medical records. Subjects were classified as nondiabetic, diabetic with HbA1c < 7% (controlled diabetes), or diabetic with HbA1c ≥ 7% (uncontrolled diabetes). Outcomes were deep venous thrombosis or pulmonary embolism within ninety days after surgery and revision surgery, deep infection, incident myocardial infarction, and all-cause rehospitalization within one year after surgery. Patients without diabetes were the reference group in all analyses. All models were adjusted for age, sex, body mass index, and Charlson Comorbidity Index.ResultsOf 40,491 patients who underwent total knee arthroplasty, 7567 (18.7%) had diabetes, 464 (1.1%) underwent revision arthroplasty, and 287 (0.7%) developed a deep infection. Compared with the patients without diabetes, no association between controlled diabetes (HbA1c < 7%) and the risk of revision (odds ratio [OR], 1.32; 95% confidence interval [CI], 0.99 to 1.76), risk of deep infection (OR, 1.31; 95% CI, 0.92 to 1.86), or risk of deep venous thrombosis or pulmonary embolism (OR, 0.84; 95% CI, 0.60 to 1.17) was observed. Similarly, compared with patients without diabetes, no association between uncontrolled diabetes (HbA1c ≥ 7%) and the risk of revision (OR, 1.03; 95% CI, 0.68 to 1.54), risk of deep infection (OR, 0.55; 95% CI 0.29 to 1.06), or risk of deep venous thrombosis or pulmonary embolism (OR, 0.70; 95% CI, 0.43 to 1.13) was observed.ConclusionsNo significantly increased risk of revision arthroplasty, deep infection, or deep venous thrombosis was found in patients with diabetes (as defined on the basis of preoperative HbA1c levels and other criteria) compared with patients without diabetes in the study population of patients who underwent elective total knee arthroplasty.