Combining single-cell RNA sequencing and population-based studies reveals hand osteoarthritis-associated chondrocyte subpopulations and pathways.

Hand osteoarthritis is a common heterogeneous joint disorder with unclear molecular mechanisms and no disease-modifying drugs. In this study, we performed single-cell RNA sequencing analysis to compare the cellular composition and subpopulation-specific gene expression between cartilage with macroscopically confirmed osteoarthritis (n = 5) and cartilage without osteoarthritis (n = 5) from the interphalangeal joints of five donors. Of 105 142 cells, we identified 13 subpopulations, including a novel subpopulation with inflammation-modulating potential annotated as inflammatory chondrocytes. Fibrocartilage chondrocytes exhibited extensive alteration of gene expression patterns in osteoarthritic cartilage compared with nonosteoarthritic cartilage. Both inflammatory chondrocytes and fibrocartilage chondrocytes showed a trend toward increased numbers in osteoarthritic cartilage. In these two subpopulations from osteoarthritic cartilage, the ferroptosis pathway was enriched, and expression of iron overload-related genes, e.g., FTH1, was elevated. To verify these findings, we conducted a Mendelian randomization study using UK Biobank and a population-based cross-sectional study using data collected from Xiangya Osteoarthritis Study. Genetic predisposition toward higher expression of FTH1 mRNA significantly increased the risk of hand osteoarthritis (odds ratio = 1.07, 95% confidence interval: 1.02-1.11) among participants (n = 332 668) in UK Biobank. High levels of serum ferritin (encoded by FTH1), a biomarker of body iron overload, were significantly associated with a high prevalence of hand osteoarthritis among participants (n = 1 241) of Xiangya Osteoarthritis Study (P-for-trend = 0.037). In conclusion, our findings indicate that inflammatory and fibrocartilage chondrocytes are key subpopulations and that ferroptosis may be a key pathway in hand osteoarthritis, providing new insights into the pathophysiology and potential therapeutic targets of hand osteoarthritis.

Apoptotic Neutrophil Membrane-Camouflaged Liposomes for Dually Targeting Synovial Macrophages and Fibroblasts to Attenuate Osteoarthritis.

No current pharmacological approach is capable of simultaneously inhibiting the symptomatology and structural progression of osteoarthritis. M1 macrophages and activated synovial fibroblasts (SFs) mutually contribute to the propagation of joint pain and cartilage destruction in osteoarthritis. Here, we report the engineering of an apoptotic neutrophil membrane-camouflaged liposome (termed "NM@Lip") for precise delivery of triamcinolone acetonide (TA) by dually targeting M1 macrophages and activated SFs in osteoarthritic joints. NM@Lip has a high cellular uptake in M1 macrophages and activated SFs. Furthermore, TA-loaded NM@Lip (TA-NM@Lip) effectively repolarizes M1 macrophages to the M2 phenotype and transforms pathological SFs to the deactivated phenotype by inhibiting the PI3K/Akt pathway. NM@Lip retains in the joint for up to 28 days and selectively distributes into M1 macrophages and activated SFs in synovium with low distribution in cartilage. TA-NM@Lip decreases the levels of pro-inflammatory cytokines, chemokines, and cartilage-degrading enzymes in osteoarthritic joints. In a rodent model of osteoarthritis-related pain, a single intra-articular TA-NM@Lip injection attenuates synovitis effectively and achieves complete pain relief with long-lasting effects. In a rodent model of osteoarthritis-related joint degeneration, repeated intra-articular TA-NM@Lip injections induce no obvious cartilage damage and effectively attenuate cartilage degeneration. Taken together, TA-NM@Lip represents a promising nanotherapeutic approach for osteoarthritis therapy.

Pedicled iliac bone flap grafting in the treatment of late presentation Legg-Calvé-Perthes disease.

Background: Legg-Calvé-Perthes disease (LCPD) is a juvenile form of ischemic femoral head osteonecrosis affecting children. The lack of effective and timely treatment results in severe sequelae in children (especially older ones). Although LCPD has been widely studied, little is known about its etiology. As a result, its clinical management is still challenging. This study will investigate the clinical and radiological results of patients older than 6 years and treated with pedicled iliac bone flap grafting for LCPD. Materials and methods: A total of 13 patients (13 hips) with late presentation of LCPD were treated with pedicled iliac bone flap grafting. Of the 13 patients, 11 were male and 2 were female. The average age of the patients was 8.4 years (range 6-13). Preoperational radiographs and pain scores were analyzed for lateral pillar classification and the Oucher scale. The final follow-up radiograph was classified using a modified Stulberg classification. Limping, extremity length inequality, and range of motion were clinically assessed. Results: The average follow-up of the patients was 70 months (range 46-120). During the surgery, seven hips were found to be lateral pillar grade B, two were grade B/C, and four were grade C. In the final examination, 12 hips were evaluated as good (Stulberg class I or II) and one as medium (Stulberg class III). There was limb shortening in one patient who was Stulberg class III. There was a significant difference between the preoperational and postoperational radiographic values and the Ocher scale, regardless of the surgical staging (P < 0.05). Conclusions: Pedicled iliac bone flap graft can treat LCPD accompanied by pain and lateral pillar stage B, B/C, and C in children over 6 years. Level of Evidence: Level IV-case series.

Clinical application of polyfoliate anterolateral thigh perforator flap with single-perforator. / 旋股外侧动脉降支单穿支分叶皮瓣的临床应用.

OBJECTIVES: The polyfoliate anterolateral thigh perforator flap needs to dissect two or more perforators, which is an ideal choice for repairing wide and irregular wounds. However, the uncertainty of perforating vessels restricts the development of this operation. This study discusses the feasibility and clinical efficacy of the polyfoliate anterolateral thigh perforator flap with single-perforator. METHODS: Fifteen patients with skin and soft tissue defects in extremities, were treated with polyfoliate anterolateral thigh perforator flap with single-perforator. Based on the perforator detected by Doppler ultrasound or color Doppler ultrasonography before operation, a polyfoliate anterolateral thigh perforator flap with single-perforator was designed. The perforating point of perforator was near the boundary of the skin paddle. Following the perforating vessels and vascular pedicles free, the vessels in the deep layer of the superficial fascia were meticulously free under the microscope. After obtaining the appropriate length, the skinpaddles were separated and recombined. After confirming the blood supply of flap, the vascular pedicle was ligated and transplanted to the recipient area. RESULTS: In 15 cases, the area of the flap was 8.0 cm×5.0 cm+6.0 cm×5.5 cm to 16.0 cm× 9.5 cm+24.0 cm×9.0 cm. All flaps survived well without necrosis and had a satisfactory appearance. The donor area was closed directly. The patients were followed up for 3 to 12 months, with an average of 6 months. The skin flaps were normal in color and good in texture. CONCLUSIONS: It's a better method to repair the skin and soft tissue defects in extremities by the polyfoliate anterolateral thigh perforator flap with single-perforator because only one perforator needs to be dissected, a group of blood vessels need to be anastomosed, and only one donor area needs to be sacrificed.

microRNA-148a-3p in extracellular vesicles derived from bone marrow mesenchymal stem cells suppresses SMURF1 to prevent osteonecrosis of femoral head.

Extracellular vesicle (EV)-associated microRNAs (miRNAs) have been found as the important biomarkers participating in the development of osteonecrosis of the femoral head (ONFH). Consequently, this study sought to examine the underlying mechanism of bone marrow mesenchymal stem cell (BMSC)-derived EVs containing miR-148a-3p in ONFH. The ONFH rat models were established. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were applied to detect miR-148a-3p, Smad ubiquitination regulatory factor 1 (SMURF1), SMAD7 and B-cell CLL/lymphoma 2 (BCL2) expression, followed by determination of relationship between miR-148a-3p and SMURF1. BMSCs were isolated from normal rats and ONFH rats, and EVs were extracted from BMSCs of normal rats. BMSCs from ONFH rats were treated with mimic, inhibitor, small interfering RNA or EVs from miR-148a-3p mimic-treated BMSCs from normal rats (BMSC-EV-miR-148a-3p mimic). Cell Counting Kit-8 and alizarin red staining were utilized to detect cell viability and osteogenic differentiation of BMSCs. ONFH rats were injected with BMSC-EV-miR-148a-3p mimic to explore the function of BMSC-EV-delivered miR-148a-3p in vivo. miR-148a-3p was down-regulated in BMSCs and EVs from ONFH rats following decreased BMSCs viability and osteogenic differentiation. SMURF1 was a target gene of miR-148a-3p, and resulted in ubiquitination and degradation of SMAD7 to decreased BCL2 expression. The proliferation and differentiation of BMSCs were promoted by BMSC-EV-miR-148a-3p mimic or SMURF1 silencing. Additionally, BMSC-EV-miR-148a-3p mimic increased cell proliferation and osteogenic response, diminished SMURF1 expression, and elevated SMAD7 and BCL2 expression in ONFH rats. Collectively, miR-148a-3p overexpressed in BMSC-EVs promoted SMAD7 and BCL2 expression by inhibiting SMURF1, thus alleviating ONFH.

Reconstructive surgery for foot and ankle defects in pediatric patients: Comparison between anterolateral thigh perforator flaps and deep inferior epigastric perforator flaps.

BACKGROUNDS: Due to the delicate tissue, small blood vessels and incomplete development of interarticular ligaments, skin and soft-tissue defects of the foot and ankle in pediatric patients remain a challenge for orthopedic and plastic surgeons. Anterolateral thigh perforator (ALTP) flap and deep inferior epigastric perforator (DIEP) flap are the most commonly used flaps for the repair of lower-extremity soft-tissue defects. The literature contains a shortage of evidence involving the differences between ALTP and DIEP flaps in the reconstruction of young patients with complex foot and ankle defects. This study was designed to determine which type of flap is better for foot and ankle repair in pediatric patients. METHODS: From January 2004 to January 2018, 79 children younger than 14 years treated with DIEP flap (41 cases) or ALTP flap (38 cases) for composite defects of the feet and ankles were retrospectively investigated. The two groups were homogeneous in terms of age, the location of the defect, etiology, and flap area. Complications, scarring, cosmetic appearance, flap sensory recovery, and functional outcome were analyzed, and statistical analysis was performed. RESULTS: The ALTP group had shorter operation time (155.0 ±â€¯12.0 min vs 212.2 ±â€¯23.9 min), flap harvested time (39.6 ±â€¯5.1 min vs 57.2 ±â€¯10.4 min), and operative blood loss (143.4 ±â€¯23.7 ml vs 170.7 ±â€¯44.7 ml) than the DIEP group (P <  0.05). In short-term follow-up, ALTP group showed a lower flap necrosis rate (5.3% vs 24.4%) and vascular insufficiency rate (2.6% vs 19.5%) than DIEP group (P <  0.05). In long-term follow-up, ALTP group showed a lower late complication rate and better cosmetic, functional, scar outcomes than DIEP group (P <  0.05). CONCLUSIONS: The study showed that an ALTP flap may brings better results than a DIEP flap in terms of short- and long-term complications, scarring, and morpho-functional outcomes for pediatric patients undergoing reconstruction of foot and ankle defects.

[Repair of resurfacing soft tissue defect of hand with radial collateral artery polyfoliate perforator flap].

OBJECTIVE: To explore the feasibility and effectiveness of radial collateral artery polyfoliate perforator flap in repair of resurfacing soft tissue defect of hand. METHODS: Between September 2017 and September 2018, the radial collateral artery polyfoliate perforator flaps were transplanted to repair 5 cases of two adjacent wounds of hand and wide or irregular wounds. All patients were male, aged from 27 to 52 years, with an average of 42.5 years. The time from injury to admission was 4 hours to 3 weeks, with an average of 7.3 days. Causes of injury included traffic accident in 2 cases, crushing injury in 2 cases, and paint injection injury in 1 case. The wounds were located at the dorsum of hand in 3 cases, the dorsum of finger in 1 case, and the thumb and thumb web in 1 case. The area of wound ranged from 8 cm×6 cm to 10 cm×8 cm. The area of skin flap ranged from 6.0 cm×3.0 cm to 11.0 cm×4.5 cm, all of which carried the posterior cutaneous nerve of the arm, and the donor site was closed directly. RESULTS: All flaps survived and healed by first intention. All patients were followed up 3-11 months (mean, 6.5 months). The patients were satisfied with the appearance of hands. The flaps were not bulky, and the color and texture were similar to the hand. There was only linear scar in the donor site, no radial nerve injury occurred, and elbow joint function was not affected. One patient underwent finger-splitting and skin flap thinning at 6 months after operation. CONCLUSION: The radial collateral artery polyfoliate perforator flap is a good method for repairing two adjacent wounds and wide or irregular wounds of hand.

[Repair of skin and soft tissue defects in extremities with the superior lateral genicular artery perforator flap].

OBJECTIVE: To investigate the feasibility and effectiveness of the superior lateral genicular artery perforator flap for repairing of soft tissue defects in extremities. METHODS: Between September 2010 and October 2017, 11 cases of skin and soft tissue in extremities were repaired with the superior lateral genicular artery perforator flap. There were 10 males and 1 female, with an average age of 37.6 years (range, 6-72 years). The causes of injury were traffic accident in 6 cases, machine injury in 1 case, falling down injury in 1 case, falling from height in 1 case, crushing injury in 1 case, and electric injury in 1 case. The defects located at the forearm in 1 case, knee in 5 cases, popliteal fossa in 2 cases, shank in 1 case, and foot and ankle in 2 cases. The area of the wound ranged from 8.0 cm×4.5 cm to 27.0 cm×8.0 cm. The interval from injury to admission was 6 days on average (range, 3-12 days). The area of perforator flap ranged from 9.0 cm×5.5 cm to 28.0 cm×9.0 cm. There were 8 cases of pedicle flap and 3 cases of free flap. All the donor sites were closed directly. RESULTS: Eight flaps survived without any complications and the donor sites healed by first intention. Two flaps had arterial crisis and 1 flap had venous crisis after operation, and the wounds healed after symptomatic treatment. There was no hematoma and secondary infections in all patients after operation. Ten patients were followed up 2-48 months (mean, 13.1 months). All flaps had satisfied appearance and texture. There was no motion limitations in the hip and knee joints of the operated legs. CONCLUSION: The superior lateral genicular artery perforator flap not only can be used to repair the soft tissue defect around the knee joint as pedicle flap, but also can be used to repair the forearm and foot skin and soft tissue defects as free flap, which is a feasible way to repair soft tissue defects in extremities.

[Clinical application of Flow-through chimeric anterolateral thigh perforator flap].

Objective: To investigate the feasibility and efficacy of the Flow-through chimeric anterolateral thigh perforator (ALTP) flap for one-stage repair and revascularization in complex defects of the extremities. Methods: Between May 2014 and June 2017, 6 patients with soft tissue defects on the limbs combined with dead space, bone defects, or tendon and joint exposure, were reconstructed with the Flow-through chimeric ALTP flap. All 6 patients were male. The patients' mean age was 44 years (range, 26-60 years). The mechanisms of injury were traffic accidents in 4 cases, wringer injury in 1 case, and bruise injury caused by heavy object in 1 case. The defects located at the lower extremity in 5 cases and at the upper extremity in 1 case. The area of the wound ranged from 7 cm×4 cm to 26 cm×10 cm. There were 3 cases of bone defect, 3 cases of joint and tendon exposure, 2 cases of chronic osteomyelitis, and 2 cases of main artery injury. The muscle flap was inserted into the deep dead space, with perforator flap for superficial defect. The area of perforator flap ranged from 10 cm×5 cm to 28 cm×11 cm and the area of muscle flap ranged from 5 cm×2 cm to 20 cm×5 cm. The defects on the donor sites were closed directly. Results: All the flaps were survival without infection and vascular crisis. The wounds of recipient and donor sites healed at first intention. The patients were followed up 3- 24 months (mean, 10 months). Good color and texture of flaps was achieved. The reconstructed main artery patency was achieved and the end of the affected limb was well transported. Only linear scar left on the donor site on thigh with no malfunction. Conclusion: The Flow-through chimeric ALTP flap can construct three-dimensional soft tissue defects without sacrificing the recipient vessels. The Flow-through chimeric ALTP flap is an reliable and ideal method for reconstruction of complex wounds in the limbs with dead space and with or without recipient major vessels injury.

Utilization of Microdissected Thin Perforator Flap Technique in the Treatment of Bulky and Deformed Skin Flaps.

BACKGROUND: This study investigates the feasibility and clinical impact of the microdissected thin perforator skin flap strategy on bulky and deformed skin flaps during second-stage revision surgery. METHODS: Seventeen patients were selected and underwent the microdissected thin perforator skin flap technique to treat bulky and deformed skin flaps after free flap reconstruction between October 2013 and October 2015. Perforator vessels were isolated and protected under a microscope. Subdermal fat with a thickness of 4 mm to 7 mm was preserved, and excess adipose tissue was resected. RESULTS: No skin flap necrosis was observed after the operation in all 17 patients, and all wounds healed without complications. Patients were followed up for 3 to 24 months, with an average follow-up time of 10 months. The skin flaps maintain normal color and texture. Both appearance and function of the recipient sites were improved significantly. CONCLUSIONS: The utilization of microdissected thin perforator flap technique to further thin bulky skin flaps at the second stage can be effective in a single operation. The blood supply of all free flaps was preserved, with no evidence of necrosis or healing complications. This technique offers an effective approach for secondary thinning of bulky free flaps.

Association between Wnt inhibitory factor-1 expression levels in articular cartilage and the disease severity of patients with osteoarthritis of the knee.

Wnt inhibitory factor (WIF)-1 is a potent extracellular Wnt antagonist which may be used as a potential molecular therapy for the treatment of inflammatory and autoimmune diseases. Although previous studies have demonstrated that WIF-1 has a protective role in experimental studies of arthritis, its role in the various disease grades of osteoarthritis (OA) remains unclear. A total of 40 patients with various stages of primary OA of the knee and 10 control subjects were enrolled in the present study. Articular cartilage specimens were harvested from subjects following total knee arthroplasty or knee above amputation. Disease severity was determined according to Modified Mankin score and cartilage tissues were ascribed to four groups: Normal, mild, moderate and severe lesions. WIF-1 expression levels in articular cartilage were measured using immunohistochemical techniques. WIF-1 expression levels were detected in all cartilage tissues. As compared with the controls, patients with OA exhibited significantly decreased WIF-1 expression levels in the articular cartilage (0.19±0.05 vs. 0.26±0.04; P<0.01). Furthermore, articular cartilage WIF-1 expression levels in the moderate and severe lesion groups were significantly reduced, as compared with the controls (P<0.01) and mild lesion group (P<0.05). Subsequent analysis demonstrated that articular cartilage WIF-1 expression levels were negatively correlated with the severity of disease (r=-0.896, P<0.001). In conclusion, the results of the present study suggested that WIF-1 expression levels in articular cartilage may be negatively associated with progressive joint damage in patients with OA of the knee; therefore, WIF-1 expression may be a potential indictor for monitoring OA disease severity.

[Propeller flap with adipofascial tissue based on peroneal artery perforator for repairing the wound with a dead space in foot and ankle].

Objective: To explore the feasibility of the propeller flap withadipofascial tissue based on peroneal artery perforator for repairing the wound with a dead space in foot and ankle. Methods: Between January 2013 to December 2014,12 wounds with a dead space in foot and ankle were treated with the propeller flap with adipofascial tissue based on peroneal artery perforator after thorough debridement. The adipofascial tissue was used to fill the dead space, the propeller flap was used to cover the superficial wound. The defect at donor site was closed directly. Results: The size of the propeller flap based on peroneal artery perforator ranged from 4 cm × 10 cm to 7 cm × 16 cm, the size of the adipofascial flap ranged from 2 cm × 4 cm to 5 cm × 7 cm. All flaps survived completely and the wounds healed primarily. The defects at donor sites got primary healing without complications. All patients were followed up for 5 to 21 months with an average of 8 months without recurrence of infection during the follow-up period. The appearance, texture, and color of the flaps were similar to those of the recipient sites. Good function of ankle was achieved. Conclusions: The propeller flap with adipofascial tissue based on peroneal artery perforator is a good option for reconstruction of foot and ankle wounds with dead space.

Relationship between Serum Magnesium Concentration and Radiographic Knee Osteoarthritis.

OBJECTIVE: To establish whether there is a relationship between serum magnesium (Mg) concentration and radiographic knee osteoarthritis (OA). METHODS: There were 2855 subjects in this cross-sectional study. Serum Mg concentration was measured using the chemiluminescence method. Radiographic OA of the knee was defined as changes consistent with Kellgren-Lawrence (K-L) grade 2 on at least 1 side. Mg concentration was classified into 1 of 4 quartiles: ≤ 0.87, 0.88-0.91, 0.92-0.96, or ≥ 0.97 mmol/l. Multivariable logistic analysis was used to test the association between serum Mg and radiographic knee OA after adjustment for potentially confounding factors. The OR with 95% CI for the association between radiographic knee OA and serum Mg concentration were calculated for each quartile. The quartile with the lowest value was regarded as the reference category. RESULTS: Significant association between serum Mg concentration and radiographic knee OA was observed in the model after adjustment for age, sex, and body mass index, as well as in the multivariable model. The multivariable-adjusted OR (95% CI) for radiographic knee OA in the second, third, and fourth serum Mg concentration quartiles were 0.90 (95% CI 0.71-1.13), 0.92 (95% CI 0.73-1.16), and 0.72 (95% CI 0.57-0.92), respectively, compared with the lowest (first) quartile. A clear trend (p for trend was 0.01) was observed. The relative odds of radiographic knee OA was decreased by 0.72 times in the fourth serum Mg quartile compared with the lowest quartile. CONCLUSION: Serum Mg concentration may have an inverse relationship with radiographic OA of the knee.