Mid- to Long-Term Results of Total Knee Arthroplasty for Charcot Arthropathy of the Knee.

Background: Total knee arthroplasty (TKA) for Charcot arthropathy of the knee is considered controversial because of its higher complication rate compared with that of TKA for osteoarthritis. In this study, we investigated the clinical outcomes, survival rates, and complications of primary TKA for Charcot arthropathy. Methods: We conducted a retrospective analysis of nine patients (12 knees) with Charcot arthropathy who underwent TKA. The mean age of the patients was 63.9 ± 9.4 years (range, 52-83 years). The most frequent causative disease was diabetes mellitus (three patients). Patients' clinical outcomes, including the 2011 Knee Society Score and the range of motion, were compared between preoperative and the most recent postoperative data. The 5- and 10-year survival rates for aseptic revision, revision due to infection, and complications were examined. The mean follow-up period was 7.3 ± 3.9 years (range, 3-14 years). Results: The 2011 Knee Society Score and the knee flexion angle significantly improved after TKA surgery (P < 0.05). The 5-year survival rates for aseptic revision, revision due to infection, and complications were 100%, 91.7%, and 83.3%, respectively; the 10-year survival rates for these parameters were the same. One patient underwent revision for insert replacement due to periprosthetic infection, and the other patient had varus/valgus instability due to soft tissue loosening. Conclusions: The mid- to long-term results of TKA for Charcot arthropathy were generally favorable. Our findings indicate that TKA may be a viable treatment option for Charcot arthropathy.

Krüppel-like factor 15 deficiency exacerbates osteoarthritis through reduced expression of peroxisome proliferator-activated receptor gamma signaling in mice.

OBJECTIVE: Krüppel-like zinc finger transcription factors (KLFs) play diverse roles in mammalian cell differentiation and development. In this study, we investigated the function of KLF15 in the progression of osteoarthritis (OA). METHODS: 0Destabilization of the medial meniscus (DMM) surgery was performed in 10-week-old male wild-type control (WT) mice and cartilage-specific KLF15 knockout (KO) mice. Histological analysis, immunohistochemistry, and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling staining were performed. Morphological changes were measured using microcomputed tomography. Six mice from each group were analyzed (total number of mice analyzed: 60). In vitro, immunofluorescence, quantitative reverse transcription-polymerase chain reaction, and western blot analyses were performed. RESULTS: KLF15 KO DMM mice exhibited significant cartilage degradation compared to WT mice. According to the Osteoarthritis Research Society International cartilage OA-histopathology scoring system, the mean sum score in KLF15 KO mice was significantly higher than that in WT mice at 8 weeks after surgery. Immunohistochemistry results revealed KLF15 KO mice exhibited reduced peroxisome proliferator-activated receptor gamma (PPARγ) expression, increased pIKKα/ß, a disintegrin-like and metalloproteinase with thrombospondin motifs (ADAMTS) 5, and Matrix metalloproteinases (MMP13) expression, and reduced Forkhead box O (FOXO1) and Light chain 3B (LC3B) expression. Inhibition of PPARγ phosphorylation accelerated the effects of interleukin (IL) 1ß-treatment in both KLF15 KO and WT chondrocytes, and activation of PPARγ expression canceled the IL1ß-induced catabolic effects. CONCLUSION: Our results indicated that the OA phenotype of KLF15 KO DMM mice was influenced by reduced PPARγ expression, including enhanced pIKKα/ß, ADAMTS5, and MMP13 expression, reduced autophagy, and increased apoptosis. KLF15 regulation may constitute a possible therapeutic strategy for the treating OA.

P21 deficiency exhibits delayed endochondral ossification during fracture healing.

INTRODUCTION: Endochondral ossification is a complex biological phenomenon involving a variety of factors and cells. Cyclin-dependent kinase inhibitor 1 (p21) inhibits cell cycle progression and is affected by external stress. We recently reported that embryonic endochondral ossification is unaffected by endogenous p21 deficiency. In this study, we evaluated whether p21 expression affects endochondral ossification during fracture healing. METHODS: Tibial fractures were introduced into p21 knockout (p21-/-) (n = 24) and wild-type C57BL/6 (p21+/+) (n = 24) mice at age 10 weeks. Fracture healing was evaluated using radiological, histological, and immunohistochemical (IHC) analyses. The effect of p21 small interfering RNA (siRNA) on ATDC5 cells was assessed in vitro. RESULTS: The Allen score for fracture healing was lower in p21-/- mice than in p21+/+ mice. In addition, p21-/- mice exhibited larger calluses and lower bone mineral density. IHC analyses showed that p21-/- mice exhibited delayed endochondral ossification via the Ihh-Runx2-Osterix pathway in vivo. Down-regulation of p21 expression in ATDC5 cells delayed endochondral ossification in vitro. CONCLUSIONS: p21 deficiency leads to delayed endochondral ossification by attenuating the Ihh-Runx2-Osterix pathway in vivo, and p21 deficiency in hypertrophic chondrocytes causes delayed differentiation of hypertrophic chondrocytes in vitro. p21 plays a role in endochondral ossification during fracture healing.

Second-Look Arthroscopic Findings and Clinical Outcomes after Adipose-Derived Regenerative Cell Injection in Knee Osteoarthritis.

Background: To evaluate the clinical outcomes and second-look arthroscopic findings after intra-articular adipose-derived regenerative cell (ADRC) injection as treatment for knee osteoarthritis (OA). Methods: ADRCs were administered to 11 patients (19 knees; mean age, 61.7 years) with knee OA. Subcutaneous adipose tissue was harvested by liposuction from both thighs, and arthroscopic lavage was performed, followed by ADRC injection (mean dose, 1.40 × 107 cells) into the synovial fluid. Outcome measures included the Knee Injury and Osteoarthritis Outcome Score, Lysholm score, and visual analog scale score. Arthroscopic examinations were performed to assess the International Cartilage Repair Society cartilage injury grade preoperatively and overall repair postoperatively. Noninvasive assessments were performed at baseline and at 1-, 3-, and 6-month follow-ups; arthroscopic assessments were performed at baseline and at 6 months. Results: All outcome measures significantly improved after treatment. This improvement was evident 1 month after treatment and was sustained until the 6-month follow-up. Data from second-look arthroscopy showed better repair in low-grade cartilage lesions than in lesions with a greater degree of damage. No patients demonstrated worsening of Kellgren-Lawrence grade, and none underwent total knee arthroplasty during this period. Conclusions: Clinical outcomes were improved in patients with knee OA after ADRC administration. Cartilage regeneration was more effective in smaller damaged lesions than in bigger lesions.

Paracrine effect of the stromal vascular fraction containing M2 macrophages on human chondrocytes through the Smad2/3 signaling pathway.

The adipose-derived stromal vascular fraction (SVF) is composed of a heterogeneous mix of adipose-derived stem cells (ADSCs), macrophages, pericytes, fibroblasts, blood, and other cells. Previous studies have found that the paracrine effects of SVF cells may be therapeutic, but their role in osteoarthritis treatment remains unclear. This study aimed to investigate the therapeutic effect of SVF cells on chondrocytes. Chondrocytes were seeded on culture plates alone (control) or cocultured with SVF or ADSCs on cell culture inserts. After 48 h of coculture, chondrocyte collagen II, tissue inhibitors of metalloproteinases-3 (TIMP-3), and matrix metalloproteinases-13 (MMP-13) messenger RNA (mRNA) expression levels were evaluated using reverse-transcription polymerase chain reaction, and the transforming growth factor-ß (TGF-ß) levels in the supernatant were measured using ELISA. Immunohistochemical staining and flow cytometry were used to evaluate the macrophages in the SVF. These macrophages were characterized according to phenotype using the F4/80, CD86, and CD163 markers. To determine whether the Smad2/3 signaling pathways were involved, the chondrocytes were pre-treated with a Smad2/3 phosphorylation inhibitor and stimulated with the SVF, and then Smad2/3 phosphorylation levels were analyzed using western blot. The mRNA expression levels of various paracrine factors and chondrocyte pellet size were also assessed. Collagen II and TIMP-3 expression were higher in the SVF group than in the ADSC group and controls, while MMP-13 expression was the highest in the ADSC group and the lowest in the controls. TGF-ß levels in the SVF group were also elevated. Immunohistochemical staining and flow cytometry revealed that the macrophages in the SVF were of the anti-inflammatory phenotype. Western blot analysis showed that the SVF increased Smad2/3 phosphorylation, while Smad2/3 inhibitors decreased phosphorylation. Smad2/3 inhibitors also reduced the expression of various other paracrine factors and decreased chondrocyte pellet size. These findings suggested that the paracrine effect of heterogeneous cells, such as anti-inflammatory macrophages, in the SVF partly supports chondrocyte regeneration through TGF-ß-induced Smad2/3 phosphorylation.

Histopathological changes of synovial tissue in rheumatoid arthritis patients treated with TNF-α inhibitors or IL-6 inhibitors.

OBJECTIVES: To investigate the cell types that undergo apoptosis in TNF-α inhibitor (TNFI)- and IL-6 inhibitor (IL-6I)-treated synovia of RA patients, and to observe and compare histological changes in them. METHODS: Synovial tissue was collected during total knee arthroplasty from 20 RA patients who were divided into three groups based on RA treatment received: conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs, control group), TNFI, or IL-6I. Tissue samples were subjected to haematoxylin and eosin staining, terminal deoxynucleotidyl transferase fluorescein-deoxyuridine triphosphate nick end labelling (TUNEL), immuno-histochemistry (IHC) and immunofluorescence staining for, respectively, histopathological assessment, apoptosis detection and IHC evaluation and scoring. RESULTS: TUNEL-positive cells were detected surrounding the discoid fibrosis unique to the TNFI group, while those in the IL-6I group were distributed widely, especially surrounding the blood vessels. IHC revealed that in TNFI-treated tissue, CD86- and CD80-positive cells were detected only in the lining and sublining layer, while CD163- and CD206-positive cells were detected more broadly; in the IL-6I-treated tissue, all four were detected widely but their levels were lower than in the control group. Immunofluorescence also revealed macrophages mainly were the apoptotic cells in the lining and sublining layers of TNFI group. TUNEL Expression levels of CD20- and CD3-positive cells were remarkably lower in the IL-6I group, compared with the control and TNFI groups. CONCLUSIONS: TNFIs and IL-6Is target different action sites and synovial cell types, resulting in histopathological features of synovium distinct from one another.

Second-look arthroscopic findings of cartilage and meniscus repair after injection of adipose-derived regenerative cells in knee osteoarthrits: Report of two cases.

BACKGROUND: The purpose of this study was to use second-look arthroscopic findings and clinical assessment to determine outcome in two cases of knee osteoarthritis treated by intra-articular knee injection of adipose-derived regenerative cells (ADRCs). CASE PRESENTATION: This study involved two patients who received ADRC therapy for knee osteoarthritis and completed the six-month post-treatment follow-up period. For each treatment, 130 mL of subcutaneous adipose tissue was harvested using tumescent liposuction technique and manual aspiration of tissue from the thigh using a suction cannula under local anesthesia in the operating room. The adipose tissue harvested was processed using the Celution® Centrifuge in a dedicated cell processing room. The ADRCs were injected into the articular cavity of both knees for one patient and into a single affected knee in the second patient (three joints). Pain and knee function were assessed using a Visual Analogue Scale (VAS) and the Knee Outcome in Osteoarthritis Score (KOOS) respectively. The cartilage defect was assessed by direct visualization (arthroscopy). No serious adverse events were reported throughout follow-up. Pain and knee function were significantly improved from baseline in all treated knees at one, three and six months after ADRCs. At six-months after ADRCs treatment, the second-look arthroscopy showed that almost all the cartilage defect areas were covered by regenerated cartilage, some cartilage fibrillation area was reduced, and meniscus tear areas were repaired. CONCLUSIONS: Cartilage and meniscus repair were observed six-months after ADRCs therapy under second-look arthroscopy. It was shown that a single administration of ADRCs might be effective as a treatment for knee osteoarthritis.