Background: To assess clinical and functional outcomes of patients aged 40 years or older receiving PCL reconstruction surgery. Methods: All patients older than 40 years with isolated PCL rupture who underwent PCL reconstruction surgery were enrolled into the retrospective study. Associated meniscal injuries, osteochondral lesions, postoperative complications, and the rate of return to the preinjury level of activity were extracted. Outcomes included International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity score. The minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were used to evaluate the clinically relevant value of PCL reconstruction in this population. Results: In total, 41 patients with a mean age of 51.7 years were included. The mean follow-up time was 32.8 months. Associated lesions included meniscal injuries (48.8%) and osteochondral lesions (97.6%). Improvement in the IKDC score (from 46.5 preoperatively to 79.0 postoperatively, p < 0.0001), Lysholm score (from 65.5 to 88.3, p < 0.0001), and Tegner activity score (from 2.3 to 4.0, p < 0.0001) was recorded. The clinically relevant value based on the MCID showed that 34 of 41 patients (82.9%) had a ΔIKDC score exceeding 16.8; all patients (100%) showed a ΔLysholm score exceeding 8.9; and 35 of 41 patients (85.4%) showed a ΔTegner activity score exceeding 0.5. Regarding the PASS, none of the patients had an IKDC score exceeding 75.9 preoperatively, whereas 27 of 41 patients (65.9%) had a score of more than 75.9 postoperatively. All patient had ≥ grade II knee instability preoperatively. Postoperatively, 36 patients (87.8%) had no significant joint translation, and 5 patients (12.2%) had grade I instability. Twenty-one patients (51.2%) returned to their preinjury level of activity. Five patients (12.2%) developed Ahlbäck grade I radiographic osteoarthritis. No rerupture or other major perioperative complications were reported. Conclusions: PCL reconstruction is a reliable surgery for middle-aged patients suffering from persistent instability even after failed conservative treatment, with significant improvement in patient-reported outcomes that exceeded MCID in the majority of patients, restoration of subjective instability, and approximately half of the patients returned to preinjury activity levels. Level of evidence: Level IV, therapeutic case series.

Sample preparation is one of the essential processes for most on-chip biochemical applications. During this process, raw reactants are diluted to specific concentration values. Current sample preparation algorithms are generally created for digital microfluidic biochips with the (1:1) mixing model. For other biochip architectures supporting multiple mixing models, such as flow-based microfluidic biochips, there is still no dedicated solution yet. Hence, in this paper, we propose the first sample preparation method dedicated to microfluidic biochips with various mixing models, named tree pruning and grafting (TPG) algorithm. It starts with a dilution tree created by regarding the (1:1) mixing model only, and then applies TPG through a bottom-up dynamic programming strategy to obtain a solution with minimal reactant consumption. Experimental results show that our algorithm can save reactant amount by up to 69% against the well-known bit-scanning method on a biochip with a four-segment mixer. Even compared with the state-of-the-art reactant minimization algorithm, it still achieves a reactant reduction of 37%. Therefore, it is convincing that the TPG algorithm is a promising sample preparation solution for biochip architectures that support various mixing models.

Background and Objectives: The efficacy of tranexamic acid (TXA) in reducing perioperative blood loss during total knee arthroplasty (TKA) is well established. However, the potential synergistic blood-conservation effect of topical fibrin sealant (Tisseel@) remains unclear. This study aims to assess the effectiveness of the combination of Tisseel and TXA during TKA. Materials and Methods: A single-blinded, prospective, randomized controlled trial was conducted with 100 patients (100 knees) undergoing primary TKA. Participants were randomly assigned to either the TXA group (n = 50), receiving intravenous (IV) TXA, or the Tisseel@ + TXA group (n = 50), receiving intra-articular Tisseel@ combined with IV TXA. The primary outcomes included blood transfusion rate, decrease in Hb level, calculated blood loss, and estimated total postoperative blood loss. Secondary outcomes involved assessing clinical differences between the groups. Results: The transfusion rate was zero in both groups. The average estimated blood loss in the Tisseel@ + TXA group was 0.463 ± 0.2422 L, which was similar to that of the TXA group at 0.455 ± 0.2522 L. The total calculated blood loss in the Tisseel@ + TXA group was 0.259 ± 0.1 L, compared with the TXA group’s 0.268 ± 0.108 L. The mean hemoglobin reduction in the first 24 h postoperatively was 1.57 ± 0.83 g/dL for the Tisseel@ + TXA group and 1.46 ± 0.82 g/dL for the TXA-only group. The reduction in blood loss in the topical Tisseel@ + TXA group was not significantly different from that achieved in the TXA-only group. The clinical results of TKA up to the 6-week follow-up were comparable between the groups. Conclusions: The combination of the topical fibrin sealant Tisseel@ and perioperative IV TXA administration, following the described protocol, demonstrated no significant synergistic blood-conservation effect in patients undergoing TKR.