Return to Cycling After Total Joint Arthroplasty.

BACKGROUND: As total joint arthroplasty (TJA) candidates become younger, patients' expectations continue to expand. We surveyed our patient population to determine rates of return to cycling after TJA so that we could provide more accurate counseling on performance and safety. METHODS: At our single institution, an online survey was generated and sent out to patients who had at least 3 months of follow-up. Patients were split into 4 categories based on surgery type: single total hip arthroplasty (THA), single total knee arthroplasty (TKA), multiple TJA, and revision TJA. RESULTS: A total of 1,029 surveys fit the inclusion criteria. The average age of the patient population was 69 years, with an average of 4.08 years from their time of most recent TJA surgery (maximum follow-up of 18.61 years). Nearly all those who were able to bike prior to surgery were able to return to cycling, with only 6% not being able to do so. There were 41.8% who returned to cycling less than three months after surgery. Most cyclists were able to return to their previous level. Patients who had a revision TJA had significantly lower rates of returning to cycling in comparison to single TKA, single THA, and multi-TJA (37.3%, 60.3%, 61.9%, and 60.3%, respectively, P < 0.005). Patients who never returned to cycling had higher revision rates in comparison to those who were able to get back on a bike (14.4 versus 9.2%, P = 0.01). CONCLUSIONS: A large proportion of patients who had prior cycling experience were able to return to bike riding within 3 to 6 months after TJA. Individuals who had revision TJA had lower rates of return to cycling in comparison to single TKA, single THA, and multi-TJA. Returning to cycling did not result in higher rates of revision.

Clinical and Computational Evaluation of an Anatomic Patellar Component.

INTRODUCTION: Anatomic patellar components for total knee arthroplasty (TKA) have demonstrated favorable in vivo kinematics. A novel failure mechanism in patients implanted with anatomic patella components was observed, prompting a clinical and computational investigation to identify patient and implant-related factors associated with suboptimal performance. METHODS: A retrospective evaluation was performed comparing 100 TKA patients implanted with anatomical versus 100 sex-, age-, and BMI-matched patients implanted with dome patellar components. All were implanted with the same posterior-stabilized (PS) TKA system with a minimum 1-year follow-up duration. Several radiographic parameters were assessed. A separate computational evaluation was performed using finite-element analysis, comparing components. Bone strain energy density was measured at the proximal and distal patellar poles. RESULTS: Patients who had anatomic patellar components had a significantly higher prevalence of anterior knee pain (AKP; 18 versus 2%, P < 0.001), chronic effusions (18 versus 2%, P < 0.001), and superior patellar pole fragmentation (36 versus 13%, P < 0.001) versus those who had dome patellar components. The anatomic group also demonstrated more lateral patellar subluxation (2.3 versus 1.1 mm, P < 0.001) and lateral tilt (5.4 versus 4.0 mm, P = 0.013). There was a higher, but not significant, number of revisions in the anatomic group (7 versus 3, P = 0.331). In computational evaluation, all simulations demonstrated increased bone strain energy density at the superior patellar pole for the anatomic patella. Resection thickness < 13 mm resulted in an over 2-fold increase in strain energy density, while a negative 7° resection angle resulted in a 6-fold higher superior pole strain energy. CONCLUSION: Patients who had this design of anatomic patellar component showed higher rates of AKP, effusion, and superior pole fragmentation than patients who had dome patellae, with higher superior patella pole strain energy confirmed on computational evaluation. Avoiding higher resection angles and excessive patellar resection may improve the performance and survivorship of the anatomic patella.

Commercial Synovial Antigen Testing is Inferior to Traditional Culture for the Diagnosis of Periprosthetic Joint Infection in Patients Undergoing Revision Total Knee Arthroplasty.

BACKGROUND: Despite its limitations, a culture remains the "gold standard" for pathogen identification in patients who have periprosthetic joint infection (PJI). Recently, a synovial fluid antigen test has been introduced by a commercial entity. The purpose of this multicenter study was to determine the accuracy of the antigen test in the diagnosis of PJI. METHODS: This retrospective study identified 613 patients undergoing revision total knee arthroplasty who had undergone preoperative synovial fluid analysis. A PJI was defined using the 2018 International Consensus Meeting (ICM) criteria. Patients who had an extended period (> 180 days) from aspiration to revision procedure (n = 62), those presenting within 90 days of their index arthroplasty procedure (n = 17), and patients who had an inconclusive ICM score (n = 8) were excluded. Using receiver operator characteristic curve analyses, we examined the utility of the microbial identification (MID) antigen test and any positive culture (either preoperative or intraoperative) in the diagnosis of PJI. RESULTS: A total of 526 patients were included. Of these, 125 (23.8%) were ICM positive and 401 (76.2%) were ICM negative. Culture demonstrated an area under the curve (AUC) of 0.864, sensitivity of 75.2%, and specificity of 97.5%. On the other hand, the MID test exhibited an AUC of 0.802, sensitivity of 61.6%, and specificity of 98.8%. The AUC of culture was significantly higher than that of the MID test (P = .037). The MID test was positive in 41.9% of culture-negative PJI cases. We also observed a high rate of discordance (29.7%) when both culture and the MID test were positive in the ICM-positive group. CONCLUSIONS: Synovial fluid antigen testing does not provide additional clinical benefit when compared to traditional cultures for the diagnosis of PJI. The antigen test had low sensitivity in the diagnosis of PJI and a relatively high rate of discordance with culture. LEVEL OF EVIDENCE: Level III.

Prevalence of Depressive Symptoms in Aseptic Revision Total Knee Arthroplasty Based on the Mode of Failure.

Background: Complications following total knee arthroplasty (TKA) that necessitate revision cause considerable psychological distress and symptoms of depression, which are linked to poorer postoperative outcomes, increased complications, and increased healthcare utilization. We aimed to identify the prevalence of mental health disorders and symptoms preoperatively and postoperatively in patients undergoing aseptic revision TKA and to stratify these patients based on their mechanism of failure. Methods: All patients undergoing aseptic revision TKA from 2008 to 2019 with a minimum 1-year follow-up were retrospectively reviewed at a single institution. Patients (n = 394) were grouped based on 7 failure modes previously described. Patients were considered to have depressive symptoms if their Veterans RAND-12 mental component score was below 42. Preoperative and postoperative Veterans RAND-12 mental component scores at the latest follow-up were evaluated. Results: Overall comparative prevalence of preoperative to postoperative depressive symptoms was 23.4%-18.8%. By mode of failure are as follows: arthrofibrosis (25.8%-16.7%), aseptic loosening (25.3%-18.9%), extensor mechanism disruption (25%-50%), failed unicompartmental knee arthroplasty (8.6%-14.3%), instability (25.7%-17.1%), osteolysis or polyethylene wear (23.1%-23.1%), and patellar failure (11.8%-23.5%). There was no difference in depressive symptoms among failure modes preoperatively (P = .376) or at the latest postoperative follow-up (P = .175). Conclusions: The prevalence of depressive symptoms in revision TKA patients appears to be independent of failure mode. Surgeon awareness and screening for depressive symptoms in this patient population preoperatively with referral for potential treatment may improve early postoperative outcomes.

Perioperative Sleep Quality Disturbances in Total Joint Arthroplasty is Multifactorial.

BACKGROUND: Sleep quality following arthroplasty procedures is important for patient recovery and satisfaction, but remains poorly understood. The purpose of this study was to report risk factors for sleep disturbances in the perioperative period in patients undergoing primary total joint arthroplasty procedures. METHODS: Sleep surveys were prospectively collected on 751 consecutive patients undergoing total joint arthroplasty at our institution between June 2019 and February 2021 at their preoperative and postoperative visits (2 and 6 weeks). Data were collected on patient demographics, opioid use (preoperatively and postoperatively) as well as tobacco and alcohol use, and specific medical diagnosis that may influence sleep patterns (ie, depression). Statistical analyses were performed using the Student's t-tests and 1-way analysis of variances. RESULTS: For both total hip and total knee patients, worse sleep patterns preoperatively were found in patients who used opioids prior to surgery (P < .001), were current smokers (P < .001), and were aged less than 65 years (P < .001). Postoperative persistent opioid use (more than 3 months) was seen in patients who had worse reported sleep quality preoperatively (P < .001). In comparison to total hip arthroplasty, patients who underwent total knee arthroplasty were more likely to report less sleep in the postoperative period. Patients who were current smokers (compared to nonsmokers or previous smokers) (P = .014) had worse sleep quality at all time points that persisted at 6 weeks, although these differences were seen more in total hip patients than in total knee patients (P = .006 versus P = .059). CONCLUSIONS: Sleep quality disturbances around the time of surgery appear to be multifactorial. LEVEL OF EVIDENCE: Therapeutic Level III.

Component Rotation in Well-Functioning, Gap Balanced Total Knee Arthroplasty Without Navigation.

BACKGROUND: Malalignment of total knee arthroplasty (TKA) components is a potential cause of clinical failure following TKA. Since the goal of a gap balancing (GB) technique is equal flexion and extension gaps secondary to soft-tissue balancing, and not necessarily component alignment, variation in component placement may exist. Our purpose was (1) to evaluate precision of component alignment in well-functioning GB TKAs performed without the aid of navigation using computed tomographic evaluation and (2) to determine any relationship between femoral version and/or tibial torsion and TKA component positioning. METHODS: There were 93 well-functioning TKAs performed with an extension gap first GB technique with a minimum 2-year follow-up evaluated using computed tomography to assess component rotational alignment, as well as osseous femoral version and tibial torsion. Femoral and tibial rotational alignment was assessed by previously described methods. RESULTS: The mean Knee Society Score was 185.7 ± 21.7. The mean range of motion was 128.5 ± 7.8°. Femoral posterocondylar axis (relative to the transepicondylar axis) values ranged from -8.3 to 4.1° with a mean of -0.78 ± 2.7° (internal rotation). Mean tibial rotation was 17.2 ± 7.9° internal rotation relative to the tibial tubercle. No correlation was found between native femoral version and femoral component rotational alignment (Pearson's correlation coefficient, r, 0.007). Weak correlation was found between native tibial torsion and tibial component alignment (r = 0.24). CONCLUSION: Despite being only a secondary objective with the GB technique, most components evaluated were within the desired range of rotation. Alignment was not influenced by native osseous rotational geometry. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Self-Reported Cannabis Use Is Associated With a Lower Rate of Persistent Opioid Use After Total Joint Arthroplasty.

Background: Legalization of cannabis, along with concern over prescription opiate use, has garnered interest in cannabis for adjuvant pain control. This study examines the relationship between cannabis and opioid consumption after total hip (THA) or knee (TKA) arthroplasty. Methods: Patients undergoing primary THA or TKA with minimum 6-month follow-up who self-reported cannabis use were retrospectively reviewed. A total of 210 patients (128 TKAs and 82 THAs) were matched by age; gender; type of arthroplasty; Charlson Comorbidity Index; and use of nicotine, antidepressants, or benzodiazepines to patients who did not self-report cannabis use. Patients receiving an opioid prescription after 90 days postoperatively were classified as persistent opioid users (POUs). Duration of opioid use (DOU) was calculated for non-POU patients as the time between surgery and their last opioid prescription. Differences in inpatient morphine milligram equivalents (MMEs), outpatient MMEs, POU, and DOU were analyzed. Results: Cannabis users required equivalent inpatient and outpatient MMEs. There was no difference in DOU. There was a significant difference in POU between cannabis users and matched controls (1.4% [n = 3] vs 9.5% [n = 20], P < .001, respectively). Grouping patients by TKA or THA, there remained a difference in POU for TKA (1.5% [n = 2] vs 10.9% [n = 14], P = .002) and THA (1.2% [n = 1] vs 7.3% [n = 6], P = .04). There was no difference in inpatient or outpatient MMEs or DOU for THA and TKA patients. Conclusions: There is a reduced rate of POU in patients who self-report perioperative cannabis use. Prospective studies are needed to clarify the role of cannabis as an adjunct to perioperative pain control.

Effectiveness of Manual Terminal Cleaning Varies on High-Touch Surfaces Near the Operative Field.

Background: Periprosthetic joint infection may result from pathogen to patient transmission within the environment. The purpose of this study is to evaluate the contamination level of selected high-touch surfaces in the operating room (OR) using a blacklight fluorescent marking system after a manual terminal clean. Methods: Prior to the manual terminal clean, 16 high-touch surfaces were marked using a blacklight fluorescent gel. The marked areas were assessed the next morning for thoroughness of cleaning. Surfaces were categorized based on the average percent of the marks removed as "clean" (>75%), "partially clean" (26%-74%), or poorly cleaned (<25%). This process was repeated randomly 12 times. Terminal cleaning was done in the standard fashion, and the perioperative team was unaware of the initiation of this study. Results: A total of 936 marks were analyzed. There was a significant difference in the number of marks completely clean (29.1%, 272/936) vs marks that were not touched (40.8%, 382/936), P < .001. Only the OR back table (75%) had a rating of clean. Partially clean areas included Mayfield table (72%), overhead lights (70.1%), infusion pump (61.1%), clock reset button (58.3%), table remote control (50%), tourniquet machine (50%), and the OR table (33.3%). Poorly cleaned surfaces included anesthesia medication cart (21.8%), door handles (20.8%), phone (16.7%), electrocautery unit (16.7%), foot pedal (16.7%), anesthesia cart (16.2%), nurses' station (14.1%), and supply cabinet doors (6%). Conclusions: Effectiveness of manual terminal cleaning varied greatly across surfaces. In general, surfaces further from the operative field were less likely to have markings removed.

Alpha-Defensin Offers Limited Utility in Work-Up Prior to Reimplantation in Chronic Periprosthetic Joint Infection in Total Joint Arthroplasty Patients.

BACKGROUND: Alpha-defensin (AD) is a synovial biomarker included in the 2018 consensus criteria for diagnosing periprosthetic joint infection (PJI). Its value in assessing eradication of infection prior to second stage reimplantation is unclear. The purpose of this study was to evaluate the impact of AD on eligibility for reimplantation following resection for chronic PJI. METHODS: This study included patients who previously underwent resection arthroplasty for PJI. Synovial fluid aspirated from 87 patients was retrospectively reviewed. All patients completed a 6-week course of intravenous antibiotics and an appropriate drug holiday. Synovial white blood cell count, percentage neutrophils, and culture from the AD immunoassay laboratory were reviewed with serum erythrocyte sedimentation rate and C-reactive protein values from our institution. A modified version of the 2018 consensus criteria was used, including white blood cell count, percentage neutrophils, erythrocyte sedimentation rate, and C-reactive protein. AD was then added to determine if it changed diagnosis or clinical management. RESULTS: Four patients were categorized as "infected" (score >6), none exhibited a positive AD or positive culture. Sixty eight patients were diagnosed as "possibly infected" (score 2 to 5), none had a positive AD, and one had a positive culture (Cutibacterium acnes). AD did not change the diagnosis from "possibly infected" to "infected" in any case or alter treatment plans. Fifteen patients had a score of <2 (not infected) and none had a positive AD. CONCLUSION: The routine use of AD in the work-up prior to a second-stage arthroplasty procedure for PJI may not be warranted.

Use of Cannabis Does Not Decrease Opioid Consumption in Patients Who Underwent Total Joint Arthroplasty.

Background: The primary purpose of this study was to determine if cannabis use decreases narcotic consumption in patients undergoing total joint arthroplasty (TJA). Material and methods: Forty-six patients undergoing a primary unilateral TJA, who self-reported the use of cannabis, were prospectively enrolled and completed this study between July 2015 and November 2019. This cohort was prospectively matched to patients who did not report cannabis use. Morphine equivalents (MEs) were averaged and recorded at 1 and 2 weeks postoperatively. Secondary outcomes and complications were recorded and reported. Results: There were no differences noted in ME during the hospitalization between the user (78.7 ± 58.5) and nonusers (70.4 ± 46.3), P = .455. ME daily average did not differ between the cohorts (user [36.8 ± 30.7] and nonuser [31.7 ± 25.6] at 1 week (P = .389) or user [22.5 ± 26.3] and nonusers [15.9 ± 18.3] at 2 weeks, P = .164, postoperatively). The total ME at 2 weeks did not differ between the user and nonuser groups (415 ± 375 vs 333 ± 275, P = .235). Pain scores at 1 week were significantly higher in patients who used cannabis (4.1 ± 1.9 vs 3.4 ± 1.6, P = .05). No differences in pain were noted during the patient's hospitalization or at 2- (P = .071) or 6-week (P = .111) follow-up. No differences in secondary outcomes or complications were noted. Conclusion: We were unable to show a decrease in narcotic consumption in patients who use cannabis undergoing primary unilateral joint replacement. These findings do not support the routine use of cannabis to decrease or supplement narcotic use after primary TJA. Level of evidence: Level II therapeutic.

Evaluation of Low-Dose Versus High-Dose Opioid Pathway in Opioid-Naïve Patients After Total Knee Arthroplasty.

BACKGROUND: Pain control after total knee arthroplasty (TKA) remains challenging. Tramadol is a weak opioid with potentially lower side effects and risk for dependency than stronger opioids. The purpose of this study was to evaluate efficacy and safety of tramadol after TKA in opioid-naïve patients compared with stronger opioids. METHODS: A retrospective review of patients who underwent primary TKA was performed. In September 2018, opioid-naïve patients were prescribed tramadol instead of oxycodone. Patients receiving tramadol (low-opioid group) were matched to patients discharged with oxycodone before this transition (high-opioid group). We compared morphine milligram equivalent (MME) consumption and outcomes up to 3 months postoperatively. RESULTS: Two-hundred and five patients underwent TKA, with 126 receiving tramadol. Fourteen patients were converted to stronger opioid (11.2% conversion rate). Seventy patients from the low-opioid group were matched to 70 patients in the high-opioid group. Average daily inpatient MME consumption was higher in the high-opioid group (40.0 ± 27.4 vs 16.3 ± 10.9, P = .000). Outpatient prescribed MME was significantly higher in the high-opioid group (135.5 ± 71.5 vs 75.3 ± 51.3, P = .000) along with a higher number of refills (0.53 ± 1.1 vs 0.886 ± 0.94, P = .041). Knee range of motion was not statistically different at any timepoint postoperatively. There was higher adverse event rate in the low-opioid group (8.6% vs 5.7%) but not statically significant. CONCLUSIONS: Low opioid regimen following TKA showed lower MME consumption than high opioid regimen with no effect on outcomes up to 3 months. Use of low opioid regimen should be considered for TKA surgery.

Incidence and Risk Factors of Orthostasis After Primary Hip and Knee Arthroplasty.

BACKGROUND: Postoperative orthostatic intolerance can limit mobilization after hip and knee arthroplasty. The literature is lacking on the incidence and risk factors associated with orthostatic intolerance after elective arthroplasty. METHODS: A retrospective case-control study of primary total hip, total knee, and unicompartmental knee arthroplasty patients was conducted. Patients with orthostatic events were identified, and potential demographic and perioperative risk factors were recorded. Orthostatic intolerance was defined as postoperative syncope, lightheadedness, or dizziness, limiting ambulation and/or requiring medical treatment. Statistical analysis was completed using Pearson's chi-square test for categorical data and t-tests for continuous data. Binary logistic regression was performed. RESULTS: A total of 500 consecutive patients were included. The overall incidence of orthostatic intolerance was 18%; 25% in total hip arthroplasty (THA) and 11% in total knee arthroplasty. On univariate analysis, significant risk factors for developing postoperative orthostatic intolerance include older age, female gender, THA surgery, lower American Society of Anesthesiologists class, absence of recreational drug use, lower estimated blood volume, lower preoperative diastolic blood pressure, spinal with monitored anesthesia care (MAC), posterior approach for THA, bupivacaine use in spinal, percent of blood loss, postoperative oxycodone or tramadol use, higher postoperative intravenous fluid volume, and lower postoperative hemoglobin. Multivariate analysis demonstrated persistent significance of female gender, THA surgery, spinal with MAC, bupivacaine use in spinal, and more intravenous fluid administered postoperatively. CONCLUSION: Orthostatic intolerance affects a significant number of arthroplasty patients. Awareness of risk factors and modification of perioperative variables linked to orthostatic intolerance may assist the surgeon in choosing the appropriate surgical setting, educating patients, and improving early postoperative recovery.

Increased Prevalence of Depressive Symptoms in Patients Undergoing Revision for Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty. Patients undergoing revision for PJI may experience psychological distress and symptoms of depression, both of which are linked to poor postoperative outcomes. We, therefore, aim to identify the prevalence of depression and depressive symptoms in patients before treatment for PJI and their link to functional outcomes. METHODS: Patients undergoing either debridement with implant retention (DAIR) or 2-stage exchange for PJI with minimum 1-year follow-up were retrospectively reviewed. The 2-stage (n = 37) and single-stage (n = 39) patients that met inclusion criteria were matched based off age (±5 years), gender, and body mass index (±5) to patients undergoing aseptic revisions. Outcomes evaluated included a preoperative diagnosis of clinical depression and preoperative and postoperative Veterans RAND 12 Item Health Survey mental component score and physical component score. RESULTS: Compared to matched controls, the prevalence of depressive symptoms was significantly greater in patients undergoing 2-stage exchange preoperatively (40.5% vs 10.8%, P < .01) but not postoperatively (21.6% vs 10.8%, P = .20). Patients undergoing DAIR with either preoperative depressive symptoms (31.3 vs 40.9, P = .05) or a preoperative diagnosis of depression (27.7 vs 43.1, P < .01) had significantly lower physical component scores postoperatively. CONCLUSIONS: Patients undergoing 2-stage exchange for PJI have a four times higher prevalence of preoperative depressive symptoms than patients undergoing aseptic revision. Patients undergoing DAIR with depression or preoperative depressive symptoms have lower functional scores postoperatively. Orthopedic surgeon screening of PJI patients with referral for treatment of depression may help improve outcomes postoperatively.

A back table ultraviolet light decreases environmental contamination during operative cases.

BACKGROUND: The purpose of this study is to assess the impact of a germicidal ultraviolet light-emitting diode (LED) on the contamination level of a back table in the operating room (OR) during total joint arthroplasty procedures. METHODS: Eight Tryptic Soy Agar petri plates were placed on a table located near the operative field and exposed to air. One plate was removed on the hour over an 8-hour time span. The back table had either an UV-LED for disinfection or a sham UV-LED. This process was repeated in 12 different ORs (6 with UV light, 6 with sham device). The plates were then incubated for 48 hours at 36°C ± 1°C . Colony forming units (CFU) were recorded 24 and 48 hours after incubation. RESULTS: There was a statistically significant difference in total CFUs between the intervention vs sham at 24-hours (27 vs 95, P = .0001) and 48-hours (38 vs 122, P < .0001). The multivariate analysis revealed that the 24-hour and 48-hour count, the predictors UV light (P = .002) and hour of plate removal (P = .050) were statistically significantly associated with CFU counts. Together, the predictor variables explained 15.8% and 23.0% of the variance in CFU counts at 24- and 48-hours, respectively. CONCLUSIONS: A back table UV-LED may decrease environmental contamination near the operative field. This has potential to lead to a decrease in joint infection.

Ten-Year Follow-Up of High-Flexion Versus Conventional Total Knee Arthroplasty: A Matched-Control Study.

BACKGROUND: High-flexion total knee arthroplasty (HF-TKA) prostheses were designed with hopes of improving knee function. Studies have suggested increased failure with HF-TKAs. The purpose is to compare clinical results of HF-TKA versus conventional TKA (C-TKA) from the same implant system with long-term follow-up. METHODS: This review of prostheses implanted between 2004 and 2007 matched 145 of 179 possible HF-TKAs with 145 of 1347 possible C-TKAs. Mean follow-up was 121.5 ± 20.3 months. We were unable to match 12 HF-TKAs. HF-TKAs with less than 8-year follow-up were excluded. The primary outcome was failure requiring revision. Secondary outcomes included range of motion (ROM), Knee Society Scores (KSS), and radiolucent lines. RESULTS: In the matched cohort, there were 15 HF-TKA reoperations, 8 of which involved component revisions. There were 12 reoperations in the C-TKA cohort but no component revisions (P = .001). The analysis of the unmatched cohorts revealed a higher revision rate for HF-TKAs (P = .039) (HF-TKA: 10/179 vs C-TKA: 27/1347). At final follow-up, HF-TKAs exhibited more prosthesis radiolucent lines without evidence of loosening. Particularly, HF-TKAs demonstrated more femoral zone IV radiolucencies (38.7%) at final follow-up compared with C-TKAs (13.8%) (P < .001). There were no differences found between cohorts in ROM or KSS. CONCLUSION: This study found an increased incidence of failure requiring revision with the HF-TKA in the matched and unmatched analyses. Higher incidences of radiolucent lines were found with HF-TKA. With no observed differences in ROM or KSS and a higher rate of failure with HF-TKA, there appears to be no advantage for use of the HF-TKA.

Incidence and Predictive Risk Factors of Postoperative Urinary Retention After Primary Total Knee Arthroplasty.

BACKGROUND: Postoperative urinary retention (POUR) after total knee arthroplasty (TKA) may cause urologic injury and delay patient discharge. This study measures the incidence of POUR and identifies predictive risk factors. METHODS: Two-hundred seventy-one consecutive patients undergoing primary unilateral TKA were prospectively enrolled. Bladder scans were performed in the postanesthesia care unit (PACU) and every four hours thereafter. POUR was defined as >400cc with inability to void and was treated with catheterization. Patient demographics, urologic history, operative data, perioperative medications, and bladder scanner volumes were investigated with the univariate and multivariate logistic regression analysis. RESULTS: Fifty-five patients (20%) developed POUR. Compared with non-POUR patients, PACU bladder scan volumes were greater in patients who developed POUR (344cc vs 120cc, P < .001). POUR patients had lower BMI (27.8 vs 29.4, P = .03), longer operative duration (83.9 vs 76.0 minutes, P = .002), and lower ASA scores (2.2 vs 2.4, P = .02). Total intravenous fluid was equivalent between groups (1134cc vs 1185cc, P = .41). POUR patients received less narcotics measured by morphine milligram equivalents (16.1 vs 23.9, P < .001). Fifteen variables including spinal type (bupivacaine and ropivacaine) and paralytic use were not predictive of POUR. Potentially predictive variables included anesthetic types administered (spinal, general, regional, and combination) and perioperative administration of nonsteroidal anti-inflammatory drugs (NSAIDs), glycopyrrolate, and muscle relaxants. The multivariate analysis showed that NSAIDs (P = .05) and glycopyrrolate (P = .04) were significant predictors. CONCLUSION: A significant percentage of patients develop POUR after TKA. Select patient demographics and PACU bladder scanning may identify those at risk. Appropriate pain control and judicious use of perioperative NSAIDs and glycopyrrolate may help minimize the risk of POUR.

Alpha-Defensin Is Not Superior to Traditional Diagnostic Methods for Detection of Periprosthetic Joint Infection in Total Hip Arthroplasty and Total Knee Arthroplasty Patients.

BACKGROUND: Synovial fluid alpha-defensin (AD) may improve diagnostic accuracy of periprosthetic joint infection (PJI) following total knee (TKA) and hip (THA) arthroplasty but is only available as send-out test. This study evaluated laboratory result accuracy between send-out test vs hospital labs and if AD made a difference in treatment plan. METHODS: A retrospective review was performed of 152 consecutive patients with a TKA or THA joint aspiration for painful or clinically concerning joint. Synovial fluid was sent to our institution (hospital-based labs, HBL) and send-out immunoassay laboratory (Synovasure). Patients were scored with specific criteria from validated scoring system for PJI using HBL and Synovasure results. The score with and without AD test was compared to determine if AD impacted patient management. RESULTS: Overall, there was strong agreement between institutions for PJI diagnosis (Cohen's kappa score 0.96). Twenty-nine patients had PJI diagnosis (score ≥6), of which 28 (97%) had positive AD with 1 false-negative result. Sixty-three patients had inconclusive score (between 2 and 5) and 60 patients had negative PJI diagnosis (score ≤1). Of these patients, 5 underwent surgery for infection. Two patients had surgery for positive AD, 2 for positive culture, and 1 because of elevated HBL results. The AD test changed the PJI diagnosis and influenced decision for surgery in only 1.3% (2/152) of patients. CONCLUSION: Minimal differences were found in laboratory values between institutions. The addition of AD may be useful in cases of equivocal laboratory results but does not appear to be necessary for routine diagnosis of PJI after TKA/THA. LEVEL EVIDENCE: Level III.

Tourniquet Use Improves Cement Penetration and Reduces Radiolucent Line Progression at 5 Years After Total Knee Arthroplasty.

BACKGROUND: Although the effect of tourniquet use during total knee arthroplasty (TKA) on functional outcomes is controversial, there are little data examining cement penetration and implant stability. This study examines the effect of tourniquet use on cement penetration and radiolucent line (RLL) progression. METHODS: Patients undergoing primary total knee arthroplasty with a single surgeon, implant, and cement with minimum 5-year follow-up were retrospectively reviewed. Tourniquet use was defined as 30 minutes minimum, while no tourniquet was 0 minutes. Patients were 1:1 matched (n = 61 per group) by age (±5), gender, body mass index (±5), and follow-up (±2 years). Cement penetration and RLL were measured on the tibia at 6 weeks, and RLL at 1, 2, and 5 years postoperatively using the Knee Society Radiographic Evaluation System. RESULTS: Cement penetration was significantly increased in the tourniquet group in anterior-posterior zones 1 (2.16 vs 1.03 mm, P < .0005), 2 (2.23 vs 1.51 mm, P < .0005), and 5 (8.56 vs 6.3 mm, P = .009), and lateral zones 1 (2.89 vs 2.17 mm, P < .0005), 2 (2.86 vs 2.12 mm, P < .0005), 3P (3.99 vs 3.5 mm, P = .039), and 5 (8.18 vs 5.93 mm, P = .006). Cumulative cement penetration averaged 34.48 vs 43.33 mm in the tourniquet group (P < .005). Progression of RLL >2 mm was observed in 27.8% (17/61) vs 11.4% (7/61) of patients in the tourniquet group (P < .005). There were 2 failures for aseptic tibial loosening in the no tourniquet group. CONCLUSION: Tourniquet use improves cement penetration and reduces RLL progression. Dryer surfaces during cementation may improve penetration, resulting in superior initial fixation strength and potentially reducing the long-term risk of aseptic loosening.

Alpha-Defensin Offers Limited Utility in Routine Workup of Periprosthetic Joint Infection.

BACKGROUND: Alpha-defensin (AD) is a synovial biomarker included as a minor criterion in the scoring system for diagnosing periprosthetic joint infection (PJI). The purpose of this study is to study the impact of AD on diagnosis and management of PJI. METHODS: Synovial fluid from 522 patients after total knee and hip arthroplasty was retrospective reviewed. Synovial white blood cell count, percentage of neutrophils, and culture from the AD immunoassay laboratory were reviewed with serum erythrocyte sedimentation rate and C-reactive protein values from our institution. A modified version of the 2018 scoring system for diagnosis of PJI was used, only scoring white blood cell count, percentage of neutrophils, erythrocyte sedimentation rate, and C-reactive protein. AD was then analyzed with these scores to determine if AD changed diagnostic findings or clinical management. RESULTS: Eight-two patients were categorized as "infected" (score ≥6), of which 76 patients had positive AD. Of the 6 "infected" patients with negative AD, 2 had positive cultures (Staphylococcus epidermidis). Two-hundred thirteen patients were diagnosed as "possibly infected" (score 2-5). Fourteen of these patients had positive AD, of which 5 had positive cultures assisting with the diagnosis. The AD test changed the diagnosis from "possibly infected" to "infected" in 8 patients (1.5%) but only altered treatment plan in 6 patients (1.1%). A score <2 (not infected) was calculated in 227 patients with no patients having positive AD. CONCLUSION: AD may be beneficial in some cases where laboratory values are otherwise equivocal; however, its routine use for the diagnosis of PJI may not be warranted.

Metal Artifact Reduction Sequence Magnetic Resonance Imaging Abnormalities in Asymptomatic Patients With a Ceramic-on-Ceramic Total Hip Replacement.

BACKGROUND: Metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) has recently gained increased utilization as a screening modality in patients with a total hip arthroplasty (THA). Fluid collections have been documented in asymptomatic patients with various bearing surfaces. The purpose of this study is to determine the frequency and types of MARS MRI-documented abnormalities in asymptomatic patients with a ceramic-on-ceramic (CoC) THA. METHODS: Thirty-seven patients (42 hips) with a minimum 2-year follow-up after THA with CoC THA implants were enrolled in this study. The inclusion criteria were the absence of hip pain and the availability of appropriate follow-up radiographs. All patients underwent a MARS MRI. Abnormalities were documented using a previously described method. RESULTS: Fluid collections were observed in 8 (19%) asymptomatic hips in this cohort. Four of the 8 hips demonstrated intracapsular synovitis, and 3 of these hips had a thickened synovium. Extra-articular fluid collections with direct intra-articular communication were identified in 4 hips, with 2 of these hips demonstrating synovial thickening. No signs of osteolysis were noted on radiographs or the MARS MRI scans. CONCLUSION: Asymptomatic fluid collections occur in patients after CoC THA similar to other bearing surfaces. We continue to follow these patients in an effort to determine the clinical significance and natural history of these findings. LEVEL OF EVIDENCE: Diagnostic Level IV.