Hypersensitive Reaction of Oxidized Regenerated Cellulose Powder in Total Knee Arthroplasty.

The powdered form of oxidized regenerated cellulose (ORC powder) is a widely used biodegradable hemostatic material in the field of surgery. There are several reports of its effectiveness and safety; however, excessive foreign body reactions remain a concern for surgeons in total knee arthroplasty (TKA). A 70-year-old woman who underwent unilateral TKA using ORC powder to control perioperative blood loss exhibited a skin rash around her operated knee at six days postoperatively. These reactions were potentially hypersensitive to ORC powder. After receiving antiallergic medication for 18 days, the skin rash disappeared. Although there are several reports on the safety of ORC powder, inadequate intraoperative lavage of the product may induce hypersensitive reactions such as skin rash.

Decision regret following opening wedge high tibial osteotomy: Older age as a risk factor.

BACKGROUND: Understanding risk factors that can predict decision regret after surgical procedures can potentially increase the quality of patient decision making and reduce decision regret after opening wedge high tibial osteotomy (OWHTO). The purpose of the present study was to identify the risk factors that predict the likelihood of decision regret after OWHTO. METHOD: Questionnaires were administered to 98 eligible OWHTO recipients more than one year post-operatively. They answered "Yes" or "No" to the question "Would you go for the same choice (OWHTO) if you had to do it over again?" Univariate and multivariate logistic regression analyses were conducted using the decision regret questionnaire as the dependent variable against patient characteristics and surgery related factors. A receiver operating characteristic curve and area under the curve were constructed and calculated for age at surgery. Cut-off values were determined using the Youden principle and receiver operating characteristic curves. RESULTS: Among the 98 respondents, 18 (18%) reported regretting their decision. Older age at surgery was the only predictive risk factor for decision regret (P < 0.01). The area under the curve for the model using age to predict failure was 0.722. The cut-off value was 71 years. Patients aged 71 years or more had a 7.841 odds ratio for decision regret (P < 0.01). CONCLUSIONS: Older age emerged as a predictive risk factor for decision regret after OWHTO. Patients aged 71 years or older had a higher decision regret rate after OWHTO than younger patients and should more carefully weigh the suitability of OWHTO against other options.

The role of substance P on maintaining ligament homeostasis by inhibiting endochondral ossification during osteoarthritis progression.

PURPOSE: Osteoarthritis (OA) is characterized by the degeneration of various tissues, including ligaments. However, pathological changes such as chondrogenesis and ossification in ligaments during OA are still unclear. Substance P (SP), a neuropeptide, has various functions including bone metabolism. This study aimed to analyze the expression and function of SP in OA ligaments, and the therapeutic potential of SP agonists in OA mice. MATERIALS AND METHODS: Expressions of SP, SOX9, and MMP13 were histologically analyzed in the posterior cruciate ligament (PCL) in humans with OA and Senescence-accelerated mouse-prone 8 (SAMP8) mice as a spontaneous OA model. The effect of SP agonists on chondrogenesis was evaluated using human ligament cells. Finally, SP agonists were administered intraperitoneally to destabilized medial meniscus (DMM) mice, and the PCL was histologically evaluated. RESULTS: In PCL of humans and mice, the expression of SP, SOX9, and MMP13 was upregulated as OA progressed, but their expression was downregulated in severe degeneration. SP and SOX9 were co-expressed in chondrocyte-like cells. In ligament cells, SP agonists downregulated SOX9, RUNX2, and COL10A1. On evaluating chondrogenesis in ligament cells, pellet diameter was reduced in those treated with the SP agonists compared to those untreated. Administration of SP agonists ameliorated PCL degeneration in DMM mice. The Osteoarthritis Research Society and ligament scores in mice with SP agonists were significantly lower than those without SP agonists. CONCLUSIONS: SP plays an important role in maintaining ligament homeostasis by inhibiting endochondral ossification during OA progression. Targeting SP has therapeutic potential for preventing ligament degeneration.

Modern cementless posterior stabilized mobile-bearing total knee arthroplasty shows comparable clinical and radiographical results to its cemented predecessor at 1-year follow-up.

PURPOSE: The purpose of this study was to evaluate perioperative and short-term clinical and radiographical results of a modern PS mobile-bearing cementless TKA system. METHODS: A retrospective review of a consecutive series of TKAs was performed by a single surgeon using a cementless or cemented TKA of the same design (Attune, DePuy Synthes, Massachusetts, USA). The 2011 Knee Society Score, Forgotten Joint Score-12, Hip-Knee-Ankle angle, and the presence of radiolucent lines (RLLs) were reviewed 1-year postoperatively with 1:1 matching performed for age, gender, body mass index, and preoperative UCLA score. Fisher's exact test or independent Student's t-test were used for statistical analyses. RESULTS: Forty-five cementless and 45 cemented TKAs were reviewed after 1:1 matching. The mean operative time was 8.8 min shorter (P < .01), and the mean amount of drainage was 40.0 ml greater (P = .04) in the cementless cohort. At 1-year postoperatively, there were no significant differences in both cohorts in 2011 Knee Scores and Forgotten Joint Scores-12, with no patients requiring revision surgery (NS). The incidence of RLLs was significantly higher in cementless TKAs (51%) than that in cemented TKAs (22%, P < .01). However, the mean width of RLLs in the cementless TKAs (0.2 mm) was significantly smaller (P < .01) than that in the cemented TKAs (0.8 mm) at 1-year postoperatively with no progression. CONCLUSION: A recently introduced cementless PS mobile-bearing TKA design demonstrated comparable postoperative and radiographical results to its cemented predecessor at 1-year follow-up. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Therapeutic effect of targeting Substance P on the progression of osteoarthritis.

OBJECTIVES: Substance P (SP) modulates NK1 and has various functions such as regulation of pain response, bone metabolism, and angiogenesis, which are recognized as important factors in osteoarthritis (OA). We aimed to evaluate the therapeutic effect of targeting SP on OA progression. METHODS: SP expression patterns were analysed histologically in articular cartilage and subchondral bone of human knees from OA patients and autopsy donors as non-OA samples and in mouse articular cartilage. Moreover, to examine the effect of SP on the progression of OA, we administered drugs to mice following the surgical destabilization of the medial meniscus: Phosphate-buffered saline (PBS), septide (NK1 receptor agonist), or aprepitant (NK1 receptor antagonist). Histological analysis and bone morphologic analysis using micro-computed tomography were performed. RESULTS: In human analysis, the expression of SP in mild OA samples was significantly higher than that in severe OA, and that in healthy cartilage was significantly higher than that in OA. In mouse analysis, Osteoarthritis Research Society International scores in the septide group were significantly lower than those in the control group. Computed tomography analysis showed that the subchondral bone's epiphysis in the control group had sclerotic change, not observed in the septide group. CONCLUSIONS: The administration of septide ameliorates OA progression through preventing subchondral bone sclerosis.

Role of vasoactive intestinal peptide in the progression of osteoarthritis through bone sclerosis and angiogenesis in subchondral bone.

OBJECTIVE: Osteoarthritis (OA) is a progressive joint disorder, with abnormal remodeling of subchondral bone linked to the disruption of cartilage metabolism. Nerves also play an important role in bone remodeling in OA progression, and vasoactive intestinal peptide (VIP), one of the neuropeptides, plays an important role in bone metabolism. The aim of this study was to analyze the expression pattern of VIP in subchondral bone, and its potential as a therapeutic target for OA progression. DESIGN: The pattern of VIP expression in the human tibia was histologically evaluated. The effect of VIP on angiogenesis was investigated using human umbilical vein endothelial cells (HUVECs). Knee OA was induced by the resection of the medial meniscotibial ligament in C57BL/6 mice. A VIP receptor antagonist was intraperitoneally administered postoperatively, and therapeutic effects were analyzed at 4 and 8 weeks. RESULTS: VIP expression in the subchondral bone increased as OA progressed in human tibia. VIP was also expressed in the vascular channels into the cartilage layer. The total length and branch points were significantly increased, due to the VIP receptor agonist in HUVECs. In OA mice, the VIP receptor antagonist could prevent cartilage degeneration and subchondral bone sclerosis. The Osteoarthritis Research Society International score in the VIP receptor antagonist group was significantly lower than in the control group. CONCLUSION: VIP is involved in the progression of OA through its effect on subchondral bone sclerosis and angiogenesis. Inhibition of VIP signaling has the potential to be a therapeutic target to prevent OA progression.