No Change in Serum Metal Ions Levels After Primary Total Hip Replacement With an Additively Manufactured Dual Mobility Acetabular Construct.

Background: Modular junctions of mixed metals have been associated with fretting and corrosion, and in extreme circumstances, adverse local tissue reactions. Since modular dual mobility (MDM) hip constructs involve a titanium shell with a modular cobalt-chromium liner, the aim of this study was to evaluate serum metal ions at minimum 1 year following total hip arthroplasty (THA) in a cohort of patients with these types of implants. Methods: A single surgeon enrolled 30 patients in a prospective study in which all patients were evaluated preoperatively with serum cobalt, chromium, and titanium metal ion levels. Patients underwent primary THA with an additively manufactured titanium acetabular shell, MDM cobalt-chromium liner, titanium cementless stem, and ceramic head. A "Four Quadrant Test" was used to ensure proper liner seating intraoperatively. At minimum 1 year following surgery, clinical and radiographic evaluation was conducted, and repeat metal ion levels were collected. Patient-reported outcome measures were collected preoperatively and postoperatively. Results: Twenty-five patients completed 1-year follow-up. All patients had normal metal ion levels for cobalt (<1 µg/L), chromium (<5 µg/L), and titanium (sensitivity test) preoperatively and postoperatively. Patient-reported outcome measures improved significantly after primary THA: Veterans RAND-12 Physical Component Score (31.05 to 45.02, P < .001), Visual Analogue Scale Pain score (70.68 to 7.77, P < .001), Hip Disability and Osteoarthritis Outcomes Score, Joint Replacement (51.99 to 86.97, P < .001). Conclusions: No significant elevation was detected in serum metal ion levels 16 months following THA using an additively manufactured titanium acetabular shell, a cobalt-chromium MDM liner, and titanium stem with a ceramic head.

Multiacquisition Variable-Resonance Image Combination Magnetic Resonance Imaging to Study Detailed Bone Apposition and Fixation of Cementless Knee System Compared to Cemented Total Knee Replacements.

Background: The ability to utilize magnetic resonance imaging (MRI) to assess bony fixation may allow a better understanding of implant design and longevity. A new cementless total knee arthroplasty (TKA) was introduced, and we hypothesized that this cementless system would show similar fixation compared to a cemented system as assessed by multispectral MRI. Methods: Multiacquisition variable-resonance image combination selective MRI was performed in 20 patients implanted with a cementless TKA. A matched control group of 20 patients who had a cemented TKA was also evaluated. Each patellar, femoral, and tibial component was graded globally as well as by specific zones. The patella zones were medial, lateral, superior, and inferior. The femoral and tibial components were divided into 4 zones: anteromedial, anterolateral, posteromedial, and posterolateral. Integration grades were performed for each zone as follows: (1) normal, (2) fibrous tissue, (3) fluid interface, (4) osteolysis. A Chi-square test was performed to detect differences in level of integration grades between patients with cemented and those with cementless TKA. Results: At average 16-month follow-up, the cementless group grading noted 0/80 (0%) vs 2/76 (2.63%) patellar zones with fluid interface, 0/80 (0%) vs 26/80 (32.5%) femoral zones with fibrous tissue, and 10/80 (12.5%) vs 17/80 (21.25%) tibial zones with fibrous tissue. The analysis showed patellar (P < .001), femoral (P < .001), and tibial (P < .001) components had improved fixation and less percentage of fibrous tissue and fluid present in the cementless TKA. Conclusions: Utilizing metal suppression MRI, a newer cementless knee implant demonstrated excellent biologic fixation and improved fixation compared to the cemented group.

Manipulation under anaesthesia after primary total knee arthroplasty : minimal differences in intravenous sedation alone versus neuraxial anaesthesia.

AIMS: Manipulation under anaesthesia (MUA) remains an effective intervention to address restricted range of motion (ROM) after total knee arthroplasty (TKA) and occurs in 2% to 3% of primary TKAs at our institution. Since there are few data on the outcomes of MUA with different anaesthetic methods, we sought to compare the outcomes of patients undergoing MUA with intravenous (IV) sedation and neuraxial anaesthesia. METHODS: We identified 548 MUAs after primary TKA (136 IV sedation, 412 neuraxial anaesthesia plus IV sedation) from March 2016 to July 2019. The mean age of this cohort was 62 years (35 to 88) with a mean body mass index of 31 kg/m2 (18 to 49). The mean time from primary TKA to MUA was 10.2 weeks (6.2 to 24.3). Pre-MUA ROM was similar between groups; overall mean pre-MUA extension was 4.2° (p = 0.452) and mean pre-MUA flexion was 77° (p = 0.372). We compared orthopaedic complications, visual analogue scale (VAS) pain scores, length of stay (LOS), and immediate and three-month follow-up knee ROM between these groups. RESULTS: Following MUA, patients with IV sedation had higher mean VAS pain scores of 5.2 (SD 1.8) compared to 4.1 (SD = 1.5) in the neuraxial group (p < 0.001). The mean LOS was shorter in patients that received IV sedation (9.5 hours (4 to 31)) compared to neuraxial anaesthesia (11.9 hours (4 to 51)) (p = 0.009), but an unexpected overnight stay was similar in each group (8.6%). Immediate-post MUA ROM was 1° to 121° in the IV sedation group and 0.9° to 123° in the neuraxial group (p = 0.313). Three-month follow-up ROM was 2° to 108° in the IV sedation group and 1.9° to 110° in the neuraxial anaesthesia group (p = 0.325) with a mean loss of 13° (ranging from 5° gain to 60° loss), in both groups by three months. No patients in either group sustained a complication. CONCLUSION: IV sedation alone and neuraxial anaesthesia are both effective anaesthetic methods for MUA after primary TKA. Surgeons and anaesthetists should offer these anaesthetic techniques to match patient-specific needs as the orthopaedic outcomes are similar. Also, patients should be counselled that ROM following MUA may decrease over time. Cite this article: Bone Joint J 2021;103-B(6 Supple A):126-130.

Is There a Synergistic Effect of Topical Plus Intravenous Tranexamic Acid Versus Intravenous Administration Alone on Blood Loss and Transfusions in Primary Total Hip and Knee Arthroplasties?

BACKGROUND: The optimal route and dosing regimen of tranexamic acid (TXA) in primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unclear. As such, we sought to analyze if there was a synergistic effect of intravenous (IV) and topical TXA on blood loss and transfusions. METHODS: We retrospectively analyzed 6720 primary TKAs and 6559 THAs performed from February 1, 2016 to December 31, 2019 at a single institution in patients who received a double IV dose (6159 TKAs and 6276 THAs) compared with a combined single IV and topical dose (561 TKAs and 283 THAs) of TXA. Multivariate logistic regression models, adjusting for age, body mass index, American Society of Anesthesiologists class, preoperative hemoglobin, and TXA administration, were performed for significant variables from a univariate analysis. RESULTS: In the TKA cohort, the mean total blood loss was statistically similar for double IV (305 mL, 95% confidence interval [CI] = 301-310 mL) TXA compared with combined TXA (310 mL, 95% CI = 299-321 mL) (P = .43). Furthermore, there was no difference in the rate of transfusion (odds ratio = 1.23, 95% CI = 0.57-2.67, P = .598). In the THA cohort, there was statistically higher blood loss with double IV (328 mL, 95% CI = 323-333 mL) TXA than in the combined group (295 mL, 95% CI = 280-310 mL) (P < .001). The rate of transfusion was statistically similar at ~2% (P = .970). CONCLUSIONS: A double IV TXA dose and a combined single IV and topical TXA dose were equally effective in minimizing blood transfusions (~2%) at primary TKA and THA. We did not find a synergistic effect when combining a systemic IV TXA with a topical TXA. LEVEL OF EVIDENCE: Level III.

Simultaneous Bilateral Primary Total Knee Arthroplasty With TXA and Restrictive Transfusion Protocols: Still a 1 in 5 Risk of Allogeneic Transfusion.

BACKGROUND: Historically, there was up to a 60% risk of blood transfusion for patients undergoing simultaneous bilateral total knee arthroplasty (SBTKA). As such, the goal of this study was to analyze the rate and risk factors for allogeneic blood transfusions in patients undergoing SBTKA with tranexamic acid (TXA). METHODS: We retrospectively identified 475 patients who underwent SBTKA with a double dose TXA regimen at a single institution from 2016 to 2019. Mean age was 65 years. Two hundred fifty-seven patients (54%) were female. Mean body mass index was 30 kg/m2. Drains were utilized in 143 patients (30%). Mean preoperative hemoglobin (Hgb) was 13.7 g/dL. Multivariate logistic regression analysis adjusting for age ≥70 years, sex, body mass index, drain use, and preoperative Hgb of <12.5 g/dL was utilized to identify risk factors for transfusion. RESULTS: One hundred six patients (22%) received an allogeneic transfusion, including 28 patients (6%) who received ≥2 units. Multivariate analysis showed that preoperative Hgb <12.5 (OR = 3.99, P < .0001), female sex (OR = 2.34, P = .002), and drain use (OR = 2.13, P = .004) were risk factors for transfusion. Forty-two patients (42/83, 51%) with a preoperative Hgb <12.5 received a transfusion compared with 64 patients (64/392, 16%) with a Hgb ≥12.5 (P < .001). CONCLUSION: Patients undergoing SBTKA with contemporary blood management still have a 1 in 5 rate of allogeneic transfusion. Drain use independently increases transfusion risk by 2-fold and should be avoided. Patients with a preoperative Hgb <12.5 have a transfusion rate of 50% and, as such, should either not undergo SBTKA or have extensive perioperative blood optimization.

GoFish: A versatile nested PCR strategy for environmental DNA assays for marine vertebrates.

Here we describe GoFish, a strategy for single-species environmental DNA (eDNA) presence/absence assays using nested PCR. The assays amplify a mitochondrial 12S rDNA segment with vertebrate metabarcoding primers, followed by nested PCR with M13-tailed, species-specific primers. Sanger sequencing confirms positives detected by gel electrophoresis. We first obtained 12S sequences from 77 fish specimens for 36 northwestern Atlantic taxa not well documented in GenBank. Using these and existing 12S records, we designed GoFish assays for 11 bony fish species common in the lower Hudson River estuary and tested seasonal abundance and habitat preference at two sites. Additional assays detected nine cartilaginous fish species and a marine mammal, bottlenose dolphin, in southern New York Bight. GoFish sensitivity was equivalent to Illumina MiSeq metabarcoding. Unlike quantitative PCR (qPCR), GoFish does not require tissues of target and related species for assay development and a basic thermal cycler is sufficient. Unlike Illumina metabarcoding, indexing and batching samples are unnecessary and advanced bioinformatics expertise is not needed. From water collection to Sanger sequencing results, the assay can be carried out in three days. The main limitations to this approach, which employs metabarcoding primers, are the same as for metabarcoding, namely, inability to distinguish species with shared target sequences and inconsistent amplification of rarer eDNA. In addition, the performance of the 20 assays reported here as compared to other single-species eDNA assays is not known. This approach will be a useful addition to current eDNA methods when analyzing presence/absence of known species, when turnaround time is important, and in educational settings.