Ultracongruent Polyethylene Liners Do Not Affect Survival of Total Knee Arthroplasty for Valgus Deformity.

BACKGROUND: Valgus knee deformity is observed in nearly 10% of patients undergoing total knee arthroplasty (TKA). The degree of polyethylene constraint required to balance a valgus knee remains controversial, and historically, posterior-stabilized (PS) designs have been favored. This study evaluated the survivorship of TKA done in valgus knees based on implant design and specifically compared posterior-stabilized (PS) and ultracongruent (UC) liners. METHODS: A total of 549 primary TKAs performed on valgus knees by fellowship-trained arthroplasty surgeons from 2013 to 2019 were reviewed. Demographics, comorbidities, degrees of preoperative deformity, implants used, and all-cause revisions until final follow-up were recorded. Cox regression analyses evaluated survival to all-cause revision in each cohort. The mean follow-up was 4.9 years (range, 2 to 9). RESULTS: There were 403 UC liners compared to 146 PS liners. There was no difference in patient age (68 versus 67 years; P = .30), body mass index (30.9 versus 30.4; P = .36), or degree of deformity (8.6 versus 8.8 degrees; P = .75) between the cohorts. At final follow-up, there were 5 revisions in the PS cohort (3.4%) versus 11 revisions in the UC cohort (2.7%) (P = .90). The most common reason for revision in both cohorts was periprosthetic joint infection (4 PS; 8 UC). Multivariable regression analyses controlling for age, body mass index, Elixhauser comorbidity score, sex, and degree of deformity demonstrated UC polyethylene liners were not associated with revision (hazard ratio 0.76; 95% confidence interval [CI] 0.26 to 2.21; P = .62). There was no difference in eight-year survivorship to all-cause revision, including aseptic and septic failure. CONCLUSIONS: Alternative polyethylene liners from the historically utilized PS liners for TKA for valgus deformity did not reduce survivorship. With modern polyethylene designs, UC inserts can be utilized for this deformity without increasing the risk of failure.

Salivary Thiocyanate as a Biomarker of Cystic Fibrosis Transmembrane Regulator Function.

Improved methods are needed to reliably assess Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) function in vivo in light of recent therapeutic developments targeting the CFTR protein. Oral fluid from patients with cystic fibrosis (CF) and healthy controls (HCs) were studied using colorimetry and nonresonant Raman spectroscopy. Colorimetry experiments showed only a 36% decrease in thiocyanate (SCN-) concentration, but a sharp Raman peak at 2068 cm-1, attributable to (SCN-) vibrations, normalized to C-H peak, was on average 18 times higher for HC samples. Samples from patients undergoing treatment with CFTR modulators including ivacaftor, lumacaftor, and tezacaftor showed a high normalized peak in response to therapy. The peak intensity was consistent in longitudinal samples from single donors and in stored samples. The Raman peak ratio is a more sensitive, convenient, noninvasive biomarker for assessments of the therapeutic efficacy of drugs targeting CFTR and provides a value that is in much better agreement with theoretical expectations of saliva SCN- concentrations compared to colorimetry. This insight may greatly facilitate assessments of CFTR modulator efficacy in individual patients.

Efficacy of Common Antiseptic Solutions Against Clinically Relevant Planktonic Microorganisms.

Prosthetic joint infections (PJIs) are among the most devastating complications after joint replacement. There is limited evidence regarding the efficacy of different antiseptic solutions in reducing planktonic microorganism burden. The purpose of this study was to test the efficacy of different antiseptic solutions against clinically relevant planktonic microorganisms. We designed an experiment examining the efficacy of several antiseptic solutions against clinically relevant planktonic microorganisms in vitro. Regarding planktonic microorganisms, povidone-iodine had 99.9% or greater reduction for all microorganisms tested except for methicillin-resistant Staphylococcus aureus, which was reduced by 60.44%. Irrisept (Irrimax Corp) had 99.9% or greater reduction for all microorganisms except Staphylococcus epidermidis (98.31%) and Enterococcus faecalis (48.61%). Bactisure (Zimmer Surgical Inc) had 99.9% or greater reduction for all microorganisms tested. Various measures exist for PJI prevention, one of which is intraoperative irrigation. We tested irrigants against clinically relevant planktonic microorganisms in vitro and found significant differences in efficacy among them. Further clinical outcome data are necessary to determine whether these solutions can impact PJI in vivo. [Orthopedics. 2022;45(2):122-127.].

All-Polyethylene Tibia: An Opportunity for Value-Based Care in Bundled Reimbursement Initiatives.

Surgeons play a critical role in making cost-effective decisions that maintain high-quality patient outcomes, which is the current focus of the Centers for Medicare & Medicaid Services. All-polyethylene tibial (APT) components often cost less during total knee arthroplasty (TKA). The authors sought to determine the relative cost savings of APT, as well as their effect on 90-day quality outcome metrics. This was a retrospective review of primary TKAs performed at a single tertiary referral center participating in the Comprehensive Care for Joint Replacement model, by 2 surgeons, from 2015 to 2017. Patient demographic data and direct hospital costs were collected, and patients were stratified by APTs vs metal-backed components. Univariable and multivariable analyses were performed for all outcome metrics. A total of 188 primary TKAs were included (92 APT, 96 metal-backed). Patients receiving APT components were older (P<.001) and had a lower body mass index (P<.001), but there was no difference in sex or American Society of Anesthesiologists score between groups. Operative time was significantly less (mean, 13 minutes) and direct surgery costs were significantly lower for APTs (P<.001). A multivariable regression model for surgical costs demonstrated significant savings (P<.001), and total hospital cost demonstrated a 6.2% average savings with APT. There was no difference in 90-day emergency department visits or re-admissions. This study demonstrates that the use of an APT is able to significantly affect not only the surgical cost but also the total hospital admission cost while maintaining equivalent 90-day outcome metrics. Strategies like this should be considered in appropriately selected patients as the incidence of TKA continues to expand. [Orthopedics. 2021;44(1):e114-e118.].

Efficacy of common antiseptic solutions against clinically relevant microorganisms in biofilm.

AIMS: Periprosthetic joint infections (PJIs) are among the most devastating complications after joint arthroplasty. There is limited evidence on the efficacy of different antiseptic solutions on reducing biofilm burden. The purpose of the present study was to test the efficacy of different antiseptic solutions against clinically relevant microorganisms in biofilm. METHODS: We conducted an in vitro study examining the efficacy of several antiseptic solutions against clinically relevant microorganisms. We tested antiseptic irrigants against nascent (four-hour) and mature (three-day) single-species biofilm created in vitro using a drip-flow reactor model. RESULTS: With regard to irrigant efficacy against biofilms, Povidone-iodine treatment resulted in greater reductions in nascent MRSA biofilms (logarithmic reduction (LR) = 3.12; p < 0.001) compared to other solutions. Bactisure treatment had the greatest reduction of mature Pseudomonas aeruginosa biofilms (LR = 1.94; p = 0.032) and a larger reduction than Vashe or Irrisept for mature Staphylococcus epidermidis biofilms (LR = 2.12; p = 0.025). Pooled data for all biofilms tested resulted in Bactisure and Povidone-iodine with significantly greater reductions compared to Vashe, Prontosan, and Irrisept solutions (p < 0.001). CONCLUSION: Treatment failure in PJI is often due to failure to clear the biofilm; antiseptics are often used as an adjunct to biofilm clearance. We tested irrigants against clinically relevant microorganisms in biofilm in vitro and showed significant differences in efficacy among the different solutions. Further clinical outcome data is necessary to determine whether these solutions can impact PJI outcome in vivo. Cite this article: Bone Joint J 2021;103-B(5):908-915.