Oral Prednisone Use Following Primary Total Knee Arthroplasty Does Not Increase Infections, But Can be Associated with Higher Risk for Medical and Surgical Complications.

INTRODUCTION: Postoperative use of oral prednisone to augment the effect of multimodal pain regimens after total knee arthroplasty (TKA) has increased in popularity. However, data on the risks of its utilization, especially as it relates to infection, has been lacking. We tested the null hypothesis that perioperative prednisone use is not associated with the incidence of surgical and medical complications after TKA. METHODS: Using a national administrative claims database, we identified 949,555 patients undergoing primary TKA. We excluded patients who filled oral prednisone prescriptions within 90 days prior to surgery or between 90 and 364 days after surgery. Patients who had acute prednisone use were defined as those who filled prednisone prescriptions only within 30 days after surgery. Outcomes consisted of surgical and medical complications after TKA. Multivariable logistic regression models were used to evaluate the association between acute prednisone use and complications, adjusting for age, sex, region, insurance plan, and Elixhauser comorbidities. RESULTS: Patients in the acute prednisone cohort had greater adjusted odds of subsequent manipulation under anesthesia (adjusted OR [odds ratio] = 1.23 [95% CI (confidence interval): 1.09 to 1.38]; P < 0.001) and lysis of adhesions (adjusted OR = 1.58 [95% CI: 1.02 to 2.33]; P = 0.03) compared to patients who did not have acute prednisone use. Patients who had acute prednisone use also had greater adjusted odds of acute kidney injury (adjusted OR = 1.47 [95% CI: 1.25 to 1.71]; P < 0.001) and pneumonia (adjusted OR = 4.04 [95% CI: 3.53 to 4.59]; P < 0.001). There was no increased incidence of infection. CONCLUSION: Prednisone use shortly following TKA may be associated with a higher incidence of certain surgical and medical complications, but without increased risk for infection. However, given these risks, the optimal patient profile for postoperative prednisone use remains to be defined.

Body morphometry did not affect the accuracy of a second-generation, miniature imageless navigation system for total hip arthroplasty (THA) using a posterior approach.

Introduction: Some modern imageless navigation platforms for total hip arthroplasty (THA) rely on virtual frontal and sagittal planes determined with the patient in the lateral decubitus position. Body morphometry that changes with gender, body mass index, and other demographic factors may affect accuracy in patient positioning and consequently, navigation accuracy. The objective of this study was to analyze the influence of patient factors on the intraoperative accuracy of a second-generation imageless computer-assisted surgery platform. Methods: 325 consecutive patients undergoing posterior approach, navigated THA arthroplasty for primary osteoarthritis by a single surgeon were retrospectively reviewed. An optic-based imageless navigation system referenced off a generic sagittal and coronal plane was used to determine acetabular inclination and anteversion. Acetabular accuracy was determined by assessing differences between intraoperative values and those obtained from measuring standardized 6-week follow-up radiographs. The effect of age, gender, BMI, race, ethnicity, and laterality on acetabular accuracy was assessed via t-tests, Pearson correlation and ANOVA. Results: Gender had a significant impact on raw inclination accuracy (females and males had an average error of 1.41° and -1.03°, respectively - p < 0.001). There was a weak correlation between acetabular accuracy and patient age and BMI as a continuous variable (both absolute γ < 0.2). No difference was found between acetabular accuracy and BMI groups. Conclusion: This second-generation imageless computer assisted device provided accurate cup positioning regardless of patient's BMI. Gender was the only factor impacting inclination accuracy.

Clinical Outcomes of Isolated Polyethylene Exchange Versus Full Component Revision for the Management of Instability Following Total Knee Arthroplasty.

BACKGROUND: Instability following total knee arthroplasty (TKA) is a common cause for revision. Isolated polyethylene exchange (IPE) can be performed to increase knee joint stability, but results have been mixed. The purpose of this study was to compare the survivorship and patient-reported outcomes of patients undergoing revision TKA for instability with IPE versus full component revision. METHODS: We reviewed 280 primary TKAs undergoing revision TKA for instability. There were 181 knees that underwent revision with IPE, compared to 99 knees treated with full component revision. The mean follow-up was 32.8 months (range, 24.8 to 82.5). Patient demographics, radiographic parameters, prosthesis constraints, reoperations for instability, and patient-reported outcomes were compared. RESULTS: The survivorship for instability was significantly higher at 2 years (99 versus 92%, P = .024) and 5 years (94 versus 84%, P = .024) for patients undergoing full component revision. Although there was no difference in Knee Injury and Osteoarthritis Outcome Score for Joint Replacements and Veterans RAND 12 physical component scores between the 2 groups at 6 weeks, 1 year, and 2 years after surgery, full revision patients reported greater pain relief (P = .006) and greater improvements in Veterans RAND 12 physical component scores (P = .027) at 1 year and Knee Injury and Osteoarthritis Outcome Score for Joint Replacements scores at 2 years (P = .017) compared to IPE patients. Men were associated with an increased risk for recurrent instability following IPE (hazard ratio 3.3, 95% confidence interval: [1.0 to 10.6]). CONCLUSIONS: Isolated polyethylene exchange was not as reliable or durable compared to full component revision for the management of postoperative instability. These procedures should only be reserved in cases with competent collaterals and when component position, offset, and rotation are optimized.

Should Chronological Age be a Consideration in Patients Undergoing Elective Primary Total Knee Arthroplasty?

BACKGROUND: The optimal time for total knee arthroplasty (TKA) requires a balance between patient disability and health state to minimize complications. While chronological age has not been shown to be predictive of complications in elective surgical patients, there is a point beyond which even optimized elderly patients would be at increased risk for complications. The purpose of this study was to examine the impact of chronological age on complications following primary TKA. METHODS: Using an administrative database, the records of 2,129,191 patients undergoing elective unilateral TKA between 2006 and 2021 were reviewed. The primary outcomes of interest were cardiac and pulmonary complications, and their relationship to the Charlson-Deyo Comorbidity Index (CDI) and chronological age. Secondary outcomes included risk of renal, neurologic, infection, and intensive care utilization postoperatively. The results were analyzed using a graphical method. The impact of chronological age as a modifier of overall risk for complications was modeled as a continuous variable. An age cutoff threshold of 80 years was also assigned for clinical convenience. RESULTS: The risk of complications correlated more closely to the CDI (odds ratio (OR) 1.37 to 2.1) than chronological age (OR 1.0 to 1.1) across the various complications [Table 1. However, beyond age 80 years, the risks of cardiac, pulmonary, renal, and cerebrovascular complications were significantly increased for all CDI categories (OR 1.73 to 3.40) compared to patients below age 80 years [Table 2] [Figures 1A and 1B]. CONCLUSIONS: Chronologic age can impact the risk of complications even in well-optimized elderly patients undergoing primary TKA. As arthroplasty continues to transition to outpatient settings and inpatient denials increase, these results can help patients, physicians, and payors mitigate risk while optimizing the allocation of resources.

Contemporary Isolated Bearing Exchange for the Management of Hip Instability Following Primary Total Hip Arthroplasty.

BACKGROUND: Isolated ball and liner exchanges (IBLEs) can be performed to increase hip joint stability, but historical results have been mixed due to a lack of head size options or dual mobility articulations. The purpose of this study was to evaluate the contemporary results of IBLEs in patients who have instability following primary total hip arthroplasty (THA). METHODS: We retrospectively reviewed 65 primary THAs from 2016 to 2020 with hip instability undergoing IBLE or conversion to dual mobility articulation. There were 31 men and 34 women who had an average age of 70 years (range, 26 to 92). The mean time to revision from primary was 40.1 months (range, 1 to 120). In 52 cases, IBLE was performed using conventional bearings, while 13 hips were converted to dual mobility. Radiographic factors, including acetabular component orientation, reproduction of hip joint offset, leg lengths, and outcomes such as recurrent instability requiring subsequent revision and patient-reported outcome measure, were recorded and compared. RESULTS: There were 12 (18.4%) hips that experienced subsequent instability and required another revision (17.3% ball and liner exchange versus 23.1% dual mobility articulation, P = .615). The mean time to rerevision for instability was 17.1 months. There were no significant differences in either acetabular component anteversion (P = .25) or restoration of hip joint offset (P = .87) in patients who required another revision for instability compared to those who did not, respectively. At 1 year, patients undergoing conventional bearing exchange reported higher Hip Dysfunction Osteoarthritis Outcome Score for Joint Replacements (P = .002) and Veterans Rand physical component (P = .023) scores compared to those who underwent a conversion to dual mobility articulation. Only age > 75 years at the time of surgery was associated with increased risk for dislocation (odds ratio 7.2, confidence interval 1.2 to 43.7, P = .032). CONCLUSIONS: Isolated bearing exchanges for instability following THA remained at high risk for subsequent instability. Conversion to dual mobility articulations did not reduce the risk of reoperation.

Alignment is only part of the equation: High variability in soft tissue distractibility in the varus knee undergoing primary TKA.

PURPOSE: The purpose of this study is to evaluate the in vivo medial and lateral joint laxities across various total knee arthroplasty (TKA) alignment categories correlated to (1) hip-knee-ankle angle, (2) proximal tibial angle and (3) distal femoral angle in a consecutive group of patients undergoing robotic-assisted TKA. METHODS: Using ligament tensions acquired during 805 robotic-assisted TKA with a dynamic ligament tensor under a load of 70-90 N, the relationship between medial and lateral collateral ligament laxity and overall limb alignment was established. Only knees with neutral or mechanical varus alignment were included and divided into five groups: neutral (0°-3°), varus 3°-5°, varus 6°-9°, varus 10°-13° and varus ≥14°. Groups were further subdivided by the intraoperative medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). The distraction of the medial and lateral sides was compared across the various alignments using an analysis of variance. RESULTS: The ability to distract the medial collateral ligament in extension and flexion was proportional to the degree of varus deformity, increasing from 4.0 ± 2.3 mm in the neutral group to 8.7 ± 3.2 mm in the varus ≥14° group (p < 0.0001). On the lateral side, the distraction of the lateral collateral ligament decreased in both extension (2.2 ± 2.4 vs. 1.2 ± 2.7, p < 0.0001) and flexion (2.8 ± 2.8 to 1.7 ± 3.0, p < 0.0001) with increasing native varus deformity. MPTA and LDFA had similar effects, where increasing MPTA varus and LDFA valgus increased medial distractibility in extension and flexion. There was significant variability of the stretch of the ligaments within and across all alignment categories, in which the standard deviation of the groups ranged from 2.0 to 3.0 mm. CONCLUSION: This study demonstrates increased medial ligament distractibility with increasing varus deformity. However, there was significant variability in ligamentous laxity within various limb alignment categories suggesting the anatomy and soft tissue identity of the knee is complex and highly variable. TKAs seeking to be more anatomic will not only need to restore alignment but also native soft tissue tensions. LEVEL OF EVIDENCE: Level III, prognostic.

Defining the Learning Period of a Novel Imageless Navigation System for Posterior Approach Total Hip Arthroplasty: Analysis of Surgical Time and Accuracy.

Introduction: The use of imageless navigation in total hip arthroplasty (THA) is frequently associated with prolonged surgical times, predominantly during the learning period. The purpose of the present study was to characterize the learning period of a novel imageless navigation system, specifically as it related to surgical time and acetabular navigation accuracy. Materials and Methods: This was a retrospective observational study of a consecutive group of 158 patients who underwent primary unilateral THA for osteoarthritis by a team headed by a single surgeon. All procedures used an imageless navigation system to measure acetabular cup inclination and anteversion angles, referencing a generic sagittal and frontal plane. Navigation accuracy was determined by assessing differences between intraoperative inclination and anteversion values and those obtained from standardized 6-week follow-up radiographs. Operative time and navigation accuracy were assessed by plotting moving averages of 7 consecutive cases. The learning period was defined using Mann-Kendall trend analyses, student t-tests and nonlinear regression modeling based on surgical time and navigation accuracy. Alpha error was 0.05. Results: The average surgical time was 67.3 min (SD:9.2) (range 45-95). The average navigation accuracy for inclination was 0.01° (SD:4.2) (range - 10 to 10), and that for anteversion was - 4.9° (SD:3.8) (range - 14 to 5). Average surgical time and navigation accuracy were similar between the first and final cases in the series with no learning period detected. Conclusions: There was no discernible learning period effect on surgical time or system measurement accuracy during the early phases of adoption for this imageless navigation system.

The John N. Insall Award: Does Melatonin Improve Subjective Sleep Quality After Total Knee Arthroplasty? A Randomized, Placebo-Controlled Trial.

BACKGROUND: Sleep disturbance is a common problem following total knee arthroplasty (TKA). The objective of this study was to determine if exogenous melatonin improves sleep quality following primary TKA. METHODS: A randomized, double-blind, placebo-controlled trial was conducted. A total of 172 patients undergoing unilateral TKA for primary knee osteoarthritis were randomized to receive either 5 mg melatonin (n = 86) or 125 mg vitamin C placebo (n = 86) nightly for 6 weeks. The primary outcome was the Pittsburgh Sleep Quality Index (PSQI) at 6 weeks and 90 days postoperatively. Secondary outcomes included 6-week and 90-day patient-reported outcome measures (PROMs), morphine milligram equivalents prescribed, medication compliance, adverse events, and 90-day readmissions. RESULTS: Mean PSQI scores worsened at 6 weeks before returning to the preoperative baseline at 90 days in both groups. There were no differences in PSQI scores between melatonin and placebo groups at 6 weeks (10.2 ± 4.2 versus 10.5 ± 4.4, P = .66) or 90 days (8.1 ± 4.1 versus 7.5 ± 4.0, P = .43). Melatonin did not improve the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Lower Extremity Activity Scale, Visual Analog Scale for pain, or Veterans Rand 12 Physical Component Score or Mental Component Score at 6 weeks or 90 days. Poor sleep quality was associated with worse PROMs at 6 weeks and 90 days on univariate and multivariable analyses, but melatonin did not modify these associations. There were no differences in morphine milligram equivalents prescribed, medication compliances, adverse events, or 90-day readmissions between both groups. CONCLUSIONS: Exogenous melatonin did not improve subjective sleep quality or PROMs at 6 weeks or 90 days following TKA. Poor sleep quality was associated with worse patient-reported function and pain. Our results do not support the routine use of melatonin after TKA.

Long-Acting Local Anesthetics for Total Knee Arthroplasty: Past, Present, and Future.

Pain management remains a challenge in the optimization of outcomes after total knee arthroplasty. Multimodal analgesia is commonplace for modern elective joint replacement, combining various medications and anesthetics along the pain pathway. Local analgesics have the advantage of avoiding systemic effects and offering concentrated local delivery of medications. Long-acting local anesthetics provide the added advantage of providing sustained pain relief when other treatment options may no longer be effective. It is important to provide an update on current local analgesic strategies available with a review of the current literature, outlining the potential benefits and unique considerations of each treatment. Novel medications in development targeting pain management following total knee arthroplasty are possible options in the future.

Preoperative Evaluation, Anesthetic Considerations, and Perioperative Oral and Parenteral Medications in Total Knee Arthroplasty.

Effective pain management protocol is critical to early mobilization, early discharge, and increasing patient satisfaction for hip and knee arthroplasty. Surgeons have tried to minimize dependence on opioids and opioid-related adverse events through multimodal protocols that use periarticular injections as well as oral and parenteral medications. The efficacy, cost, and adverse effects of each of these components need to be considered when formulating an evidence-based multimodal pain protocol. Recent advancements have changed understanding of the variability in metabolism of commonly given agents around the time of surgery. It is important to provide a systematic approach to the preoperative evaluation, anesthetic considerations, and the administration of oral and parenteral medications routinely used in total knee arthroplasty.

Why and What Happens to Patients Younger Than 60 Years Who Need Revision Total Knee Arthroplasty?

BACKGROUND: With the increasing number of young patients undergoing primary total knee arthroplasty (TKA), there will be an increase in the number of patients who require revision. While the results of TKA in younger patients are well known, there is little information regarding to the outcomes of revision TKA in this population. The purpose of this study was to evaluate the clinical outcomes in patients <60 years of age undergoing aseptic revision TKA. METHODS: We retrospectively reviewed 433 patients undergoing aseptic revision TKA between 2008 and 2019. There were 189 patients <60 years compared to a group of 244 patients >60 years undergoing revision TKA for aseptic failures in terms of implant survivorships, complications, and clinical outcomes. Patients were followed for a mean of 48 months (range, 24 to 149). RESULTS: A total of 28 (14.8%) patients less than 60 years of age required repeat revision compared to 25 (10.2%) 60 years or older (odds ratio (OR) 1.94, 95% confidence interval (CI) 0.73-5.22, P = .187). There were no differences regarding postprocedural Patient-Reported Outcomes Measurement Information System (PROMIS) physical health scores (72.3 ± 13.7 versus 72.0 ± 12.0, P = .66) and PROMIS mental health scores (66.6 ± 17.4 versus 65.8. ± 14.7, P = .72), at an average of 32.9 and 30.7 months, respectively. Postoperative infection occurred in 3 (1.6%) patients <60 years of age, while 12 (4.9%) postoperative infections occurred in patients 60 years or older (OR 0.75, 95% CI 0.06-10.2, P = .83). CONCLUSION: There were no statistically significant differences in clinical outcomes between patients <60 versus > 60 years of age undergoing aseptic revision TKA.

The Microbiome of Osteoarthritic Hip and Knee Joints: A Prospective Multicenter Investigation.

BACKGROUND: Recent advances in high-throughput DNA sequencing technologies have made it possible to characterize the microbial profile in anatomical sites previously assumed to be sterile. We used this approach to explore the microbial composition within joints of osteoarthritic patients. METHODS: This prospective multicenter study recruited 113 patients undergoing hip or knee arthroplasty between 2017 and 2019. Demographics and prior intra-articular injections were noted. Matched synovial fluid, tissue, and swab specimens were obtained and shipped to a centralized laboratory for testing. Following DNA extraction, microbial 16S-rRNA sequencing was performed. RESULTS: Comparisons of paired specimens indicated that each was a comparable measure for microbiological sampling of the joint. Swab specimens were modestly different in bacterial composition from synovial fluid and tissue. The 5 most abundant genera were Escherichia, Cutibacterium, Staphylococcus, Acinetobacter, and Pseudomonas. Although sample size varied, the hospital of origin explained a significant portion (18.5%) of the variance in the microbial composition of the joint, and corticosteroid injection within 6 months before arthroplasty was associated with elevated abundance of several lineages. CONCLUSIONS: The findings revealed that prior intra-articular injection and the operative hospital environment may influence the microbial composition of the joint. Furthermore, the most common species observed in this study were not among the most common in previous skin microbiome studies, suggesting that the microbial profiles detected are not likely explained solely by skin contamination. Further research is needed to determine the relationship between the hospital and a "closed" microbiome environment. These findings contribute to establishing the baseline microbial signal and identifying contributing variables in the osteoarthritic joint, which will be valuable as a comparator in the contexts of infection and long-term arthroplasty success. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Spine or Hip First? Outcomes in Patients Undergoing Sequential Lumbar Spine or Hip Surgery.

BACKGROUND: Lumbar spine pathology frequently coexists in patients who have hip arthrosis. There is controversy on whether lumbar or hip pathology should be first addressed. The purpose of this study was to evaluate the outcomes of sequential lumbar spine (LSP) or hip arthroplasty (THA). METHODS: Using a large national database from 2010 to 2020, we reviewed the records of 241,279 patients who had concurrent hip arthritis and lumbar spine disease defined as spinal stenosis, lumbar radiculopathy, or degenerative disc disease. During the study period, 6,458 (2.7%) patients with concurrent hip/spine disease underwent sequential operative treatment of either the hip joint or lumbar spine within 2 years. The rates of subsequent surgery in either the hip or the spine, opioid requirements, and rates of hip dislocation were determined and analyzed using compared Chi-squared analyses. RESULTS: Patients undergoing THA first had lower risk of subsequent spinal procedure compared to patients who had spinal procedures first (5.7 versus 23.7%, P < .001). This disparity was maintained up to 5 years (P < .001). Opioid requirements at 1 year were highest in patients who underwent spinal procedures only (836 pills/patient) compared to any other group THA only (566 pills/patient), LSP and then THA (564 pills/patient), THA and LSP (586 pills/patient). Also, THA following LSP was associated with significantly higher rates of dislocation compared to patients undergoing THA first (3.2 versus 1.9%, P < .001). CONCLUSION: Total hip arthroplasty first in patients who have concurrent spine disease was associated with lower risk of subsequent surgery, opioid requirement, and risk of postoperative instability compared to patients having lumbar procedure first.

Wound complications following revision total knee arthroplasty: Prevalence and outcomes.

BACKGROUND: Wound complications following revision TKA can be catastrophic and can compromise joint and even limb. The purpose of this study was to determine the prevalence of superficial wound complications requiring return to the OR in revision TKA, rates of subsequent deep infection, factors that increase the risk of superficial wound complications, and the outcomes of revision TKA following development of superficial wound complications. METHODS: We retrospectively reviewed 585 consecutive TKA revisions with at least two years follow-up, including 399 aseptic revisions and 186 reimplantations. Superficial wound complications without deep infection requiring return to the OR within 120 days were compared to controls. RESULTS: Fourteen patients following revision TKA (2.4%) required return to the OR for a wound complication, including 7 of 399 (1.8%) patients who underwent aseptic revision TKA and 7 of 186 (3.8%) patients undergoing reimplantation TKA (p = 0.139). Aseptic revisions with wound complications were more likely to develop subsequent deep infection (HR 10.04, CI 2.24-45.03, p = 0.003), but this did not hold true for reimplantations (HR 1.17, CI 0.28-4.91, p = 0.829). Risk factors for wound complication included atrial fibrillation when all patients were combined (RR 3.98, CI 1.15-13.72, p = 0.029), connective tissue disease in the aseptic revision group (RR 7.1, CI 1.1-44.7, p = 0.037), and a history of depression in the re-implantation group (RR 5.8, CI 1.1-31.5, p = 0.042).

What is the Value of a Balanced Total Knee Arthroplasty? Getting It Right the First Time.

BACKGROUND: Instability is a leading cause of early failure following total knee arthroplasty (TKA). Enabling technologies can improve accuracy, but their clinical value remains undetermined. The purpose of this study was to determine the value of achieving a balanced knee joint at the time of TKA. METHODS: A Markov model was developed to determine the value from reduced revisions and improved outcomes associated with TKA joint balance. Patients were modeled for the first 5 years following TKA. The threshold to determine cost-effectiveness was set at an incremental cost effectiveness ratio of $50,000/quality-adjusted life year (QALY). A sensitivity analysis was performed to evaluate the influence of QALY improvement (ΔQALY) and Revision Rate Reduction on additional value generated compared to a conventional TKA cohort. The impact of each variable was evaluated by iterating over a range of ΔQALY (0 to 0.046) and Revision Rate Reduction (0% to 30%) and calculating the value generated while satisfying the incremental cost effectiveness ratio threshold. Finally, the impact of surgeon volume on these outcomes was analyzed. RESULTS: The total value of a balanced knee for the first 5 years was $8,750, $6,575, and $4,417 per case, for low, medium, and high-volume surgeons, respectively. Change in QALY accounted for greater than 90% of the value gain with a reduction in revisions making up the rest in all scenarios. The economic contribution of revision reduction was relatively constant regardless of surgeon volume ($500/case). CONCLUSION: Achieving a balanced knee had the greatest impact on ΔQALY over early revision rate. These results can help assign value to enabling technologies with joint balancing capabilities.

Dual-Mobility Articulations in Total Hip Arthroplasty: A Durable Game Changer or the Next Cause for Concern?

The use of dual-mobility articulations in total hip arthroplasty (THA) is increasing. The appeal of dual-mobility implants rests in their ability to increase the effective ball head size for a given THA construct compared with conventional bearings, thereby reducing the risk of postoperative instability. Although the concept of dual-mobility articulation in THA is not new and early clinical experience dates back to the 1970s, its widespread use is a relatively recent phenomenon. Furthermore, unlike European surgeons who routinely use monoblock dual-mobility acetabular components in THA, the most common dual-mobility implants used in North America and worldwide are of a modular nature in which a metallic liner is coupled to a multibearing acetabular component and thus creating a metal-on-metal interface. It is important to review the evidence for the indications for dual-mobility implants in both primary and revision THA; present basic science data on the risk of corrosion in modular dual-mobility implants; and highlight the possible ongoing questions and concerns with dual-mobility implants. The goal is to provide a balanced critical review of this technology and define its current place in the hip surgeon's armamentarium.

HTX-011 in Combination with Multimodal Analgesic Regimen Minimized Severe Pain and Opioid Use after Total Knee Arthroplasty in an Open-Label Study.

Total knee arthroplasty (TKA) can be associated with significant postoperative pain despite multimodal analgesic (MMA) protocols, and most patients require the use of opioids postoperatively. HTX-011 is a dual-acting local anesthetic containing bupivacaine and low-dose meloxicam in an extended-release polymer. In a prior randomized controlled trial (RCT), HTX-011 reduced pain and opioid use through 72 hours after TKA compared with bupivacaine hydrochloride. This open-label study (NCT03974932) evaluated the efficacy and safety of HTX-011 combined with an MMA regimen in patients undergoing TKA under spinal anesthesia. All patients received intraoperative HTX-011 (400 mg bupivacaine/12 mg meloxicam) in combination with an MMA regimen consisting of preoperative acetaminophen, celecoxib, and pregabalin and postoperative acetaminophen and celecoxib until discharge. Opioid rescue was allowed upon patient request for additional pain control. Pain scores, opioid consumption, discharge readiness, and adverse events were recorded. Fifty-one patients were treated. Compared with the prior RCT, HTX-011 with this MMA regimen further lowered pain scores and reduced opioid use. Mean patient-reported pain scores remained in the mild range, and 82% of patients or more did not experience severe pain at any individual time point through 72 hours after surgery. Mean total opioid consumption was low over 72 hours: 24.8 morphine milligram equivalents (1-2 tablets of oxycodone 10 mg/day). Approximately 60% of patients were ready for discharge by 12 hours, and 39% were discharged without an opioid prescription and did not call back for pain management. The treatment regimen was well tolerated, and no added risk was observed with the addition of MMA. HTX-011 with an MMA regimen reduced postoperative pain and opioid use following TKA.

Personalizing Revision Tibial Baseplate Position and Stem Trajectory With Custom Implants Using 3D Modeling to Optimize Press-fit Stem Placement.

Background: A common tibial construct for revision total knee arthroplasty includes a long diaphyseal engaging press-fit stem. Due to tibial canal bowing, compromises are often necessary to match patient anatomy when choosing stemmed implants. The objective of this study is to determine through 3-D modeling whether current implant press-fit options appropriately fit patient anatomy, or whether an alternative angle between the stem and baseplate could increase the cortical engagement of long press-fit tibial stems. Methods: Preoperative computerized tomography scans from 100 patients undergoing TKA were imported into an image-processing software program. Three-dimensional models were created with tibial stems placed at a fixed perpendicular angle and a custom angle to the revision tibial baseplate. Stem diameter, depth, offset, and contact surface area were measured and analyzed between the 2 groups. Results: Significantly more cortical contact, larger stem diameter, and smaller offset of the custom keel from the center of the baseplate were associated with free custom tibial stem placement vs a fixed perpendicular baseplate-stem interface (P < .001). Statistically significant differences were also found between different patient demographics. Conclusions: Custom free-angle stem placement allows for increased stem diameter and cortical contact of press-fit tibial stems compared to existing constructs that must interface with the baseplate at a 90-degree angle. Current revision tibia implants limit fixation of tibial press-fit stems and often mismatch with patient anatomy. Alternative ways to fit patient anatomy may be beneficial for patients with extreme mismatch. In the future, custom keel angles may help to resolve this problem.

An Enhanced Understanding of Culture-Negative Periprosthetic Joint Infection with Next-Generation Sequencing: A Multicenter Study.

BACKGROUND: The challenges of culture-negative periprosthetic joint infection (PJI) have led to the emergence of molecular methods of pathogen identification, including next-generation sequencing (NGS). While its increased sensitivity compared with traditional culture techniques is well documented, it is not fully known which organisms could be expected to be detected with use of NGS. The aim of this study was to describe the NGS profile of culture-negative PJI. METHODS: Patients undergoing revision hip or knee arthroplasty from June 2016 to August 2020 at 14 institutions were prospectively recruited. Patients meeting International Consensus Meeting (ICM) criteria for PJI were included in this study. Intraoperative samples were obtained and concurrently sent for both routine culture and NGS. Patients for whom NGS was positive and standard culture was negative were included in our analysis. RESULTS: The overall cohort included 301 patients who met the ICM criteria for PJI. Of these patients, 85 (28.2%) were culture-negative. A pathogen could be identified by NGS in 56 (65.9%) of these culture-negative patients. Seventeen species were identified as common based on a study-wide incidence threshold of 5%. NGS revealed a polymicrobial infection in 91.1% of culture-negative PJI cases, with the set of common species contributing to 82.4% of polymicrobial profiles. Escherichia coli, Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus ranked highest in terms of incidence and study-wide mean relative abundance and were most frequently the dominant organism when occurring in polymicrobial infections. CONCLUSIONS: NGS provides a more comprehensive picture of the microbial profile of infection that is often missed by traditional culture. Examining the profile of PJI in a multicenter cohort using NGS, this study demonstrated that approximately two-thirds of culture-negative PJIs had identifiable opportunistically pathogenic organisms, and furthermore, the majority of infections were polymicrobial. LEVEL OF EVIDENCE: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.