Partial Cartilage Research Articles

Melatonin Attenuates the Progression of Osteoarthritis in Rats by Inhibiting Inflammation and Related Oxidative Stress on the Surface of Knee Cartilage.

ObjectiveTo investigate the correlation between melatonin and osteoarthritis (OA) in rats. To explore the relevant mechanisms in the occurrence and development of osteoarthritis in rats, and to further understand the disease of osteoarthritis.MethodsForty healthy 6‐month‐old male SD rats were randomly divided into two groups: sham and drug intervention groups. Pre‐OA modeling, enzyme‐linked immunosorbent assay was employed to detect the levels of IL‐1β, IL‐6, COX‐2, and melatonin in the serum of the rats in each group. For OA modeling, we administered an injection of papain into the knee cavity of all rats. The levels of IL‐1β, IL‐6, and COX‐2 in the serum of rats in each group were detected 2 weeks after the modeling. Additionally, 2 weeks after the modeling, the rats in the drug intervention group were intraperitoneally injected with melatonin antagonists. The rats in the sham group were intraperitoneally injected with normal saline for 2 weeks. The levels of IL‐1β, IL‐6, and COX‐2 in the serum of each group were measured at the second, third, and fourth weeks after the drug intervention, and the levels of melatonin in the serum were measured at the second week after the drug intervention. Finally, the rats were euthanized by cervical dislocation, and pathological sections were collected from the knee joint to observe the pathological tissue changes under a microscope, and Mankin score was determined. The independent samples t‐test method was used for analysis.ResultsThe imaging examination after the drug intervention showed that the modeling of knee osteoarthritis in rats was successful. In the pathological findings, HE staining showed a legible cartilage structure of each layer, with cartilage proliferation and partial cartilage tearing to the radial layer. The tide line was intact; toluidine blue staining revealed more obvious changes. The differences among the mean values of IL‐6, IL‐1β, and COX‐2 measured in each period were statistically significant (t = 5.50, p < 0.05). The measured mean values of IL‐6, IL‐1β, and COX‐2 revealed statistically significant differences among the groups (t = 2.01, p < 0.05). The intergroup comparison of the Mankin scores in each period showed statistically significant differences.ConclusionMelatonin may inhibit inflammation and associated oxidative stress on the surface of knee cartilage. It may be related to the repair and regeneration of articular surface cartilage during the development of OA in the rat knee joint.

Arthritis remission with partial cartilage restoration in a 9-year-old female with hip chondrolysis following treatment with adalimumab.

Hip chondrolysis is observed primarily or secondary to other diseases and is a rare but yet debilitating disease, characterised by loss of cartilage of the femoral epiphysis and significant restriction of motion. We present the case of a 9-year-old female diagnosed with hip chondrolysis associated with probable juvenile psoriatic arthritis. Avoidance of weight-bearing activities and treatment with corticosteroids, methotrexate, and adalimumab followed by aquatic therapy resulted in clinical and radiographic improvement as well as partial cartilage regeneration.

Stem Cells Promote the Regeneration of Knee Joint Degenerative Bone and Articular Cartilage.

Cartilage damage has a certain ability to spontaneously repair, but the repaired tissue often shows the phenomenon of cartilage terminal differentiation, which causes irreversible damage to its structure and function and seriously affects the quality of life and work of patients. It is of great significance to study the problems encountered in the process of cartilage damage repair. This article mainly studied stem cells to promote the regeneration of knee joint degenerative bone articular cartilage. First, the animal articular cartilage defect is modeled, 10 ml of animal venous blood is drawn, 0.5 ml of PRP is collected by centrifugation, mixed with cartilage fragments, and transplanted into the defect area into a gel. In the BMSCs group, 1 ml of BMSCs with a cell concentration of 107 cells/ml was injected intra-articularly. The histological chromosomes were observed after 6 weeks and 12 weeks, and the effect of cartilage tissue repair was analyzed and evaluated, and the related data were statistically analyzed. We evaluated the spontaneous repair ability of partial cartilage damage, full-thickness cartilage damage, and osteochondral damage. Furthermore, for partial cartilage damage repair, by using the cartilage damage in vitro model and biomaterials to simulate the in vivo microenvironment, the adhesion and cell morphology on the surface of partial- and full-thickness cartilage damage were evaluated, and the experiments were further used to evaluate the exogenous and internal induced migration effect of source on cultured cells in vitro. In the cell concentration study, the cartilage repair effect increased with the increase in concentration within a certain range, and the tissue repair ability remained stable when the concentration exceeded 107 cells/ml. Using ECM-oriented scaffolds to compound autologous BMSCs, tissue-engineered cartilage was successfully constructed, which had the histological and biochemical characteristics of normal cartilage tissue, and better repaired the damaged articular cartilage of large animals.

Solitary Plasmacytoma of The Sternal Stalk: A Case Report and Literature Review

Background: It has been reported that sternal neoplasms are a rare disease, accounting for about 1% of primary bone neoplasms, of which about 60% are malignancy, mostly occurring in the manubrium sternum. Case presentation: We reviewed a 77-year-old man with a solitary plasmacytoma of the sternal stalk presenting with pain in the anterior chest wall by examining a preoperative diagnosis of sternal manubrium malignant bone tumor. We performed extensive sternal manubrium tumor resection + bilateral partial costal cartilage resection + bilateral clavicular head resection + cervical lymph node dissection + thoracic reconstruction, and the postoperative recovery was perfect. Conclusion: We report a rare case of solitary plasmacytoma of the manubrium sternum successfully treated by extensive radical surgery for the manubrium tumor. Although rare, the disease should be identified, examined, and treated early to avoid serious complications.

Effect of Systemic Administration of Granulocyte Colony-Stimulating Factor on a Chronic Partial-Thickness Cartilage Defect in a Rabbit Knee Joint.

Cartilage lesions in the knee joint can lead to joint mechanics changes and cause knee pain. Bone marrow stimulation (BMS) promotes cartilage regeneration by perforating the subchondral bone just below the injury and inducing bone marrow cells. This study aimed to investigate whether systemic administration of granulocyte colony-stimulating factor (G-CSF) with BMS improves repair of chronic partial-thickness cartilage defects (PTCDs). Eighteen 6-month-old New Zealand white rabbits were divided into 3 groups: control (C, n = 6), BMS alone (n = 6), and BMS + G-CSF (n = 6). Partial cartilage defects with 5 mm diameter were created in the trochlear region of both knees; after 4 weeks, the BMS alone and BMS + G-CSF groups underwent BMS; G-CSF (50 µg/kg) or saline was administered subcutaneously for 5 days starting from 3 days before BMS. At 8 and 16 weeks after cartilage defect creation, the area of cartilage defects was macroscopically and histologically evaluated. International Cartilage Repair Society (ICRS) grades for macroscopic assessment were 0, 0.7, and 0.7 at 8 weeks and 0, 1.2, and 1.3 at 16 weeks in the C, BMS, and BMS + G-CSF groups, respectively. Wakitani scores for histological assessment were 9.8, 8.7, and 8.2 at 8 weeks and 9.5, 9, and 8.2 at 16 weeks in the C, BMS, and BMS + G-CSF groups, respectively. The BMS + G-CSF group showed significantly more repair than the C group, but there was no difference from the BMS group. The effect of BMS and G-CSF on chronic PTCDs in mature rabbit knees was limited.

Decannulation after cricotracheostomy: a comparison of partial cricoid cartilage resection with conventional tracheostomy

Background Cricotracheostomy, a modified procedure to open the airway with partial cricoid cartilage resection, was recently reported to be useful in selected cases. Aims/objectives To examine decannulation outcomes in patients who underwent cricotracheostomy by comparing it with a conventional tracheostomy. Materials and methods Data from 127 consecutive adult patients, who underwent either conventional tracheostomy or cricotracheostomy between 2016 and 2019, were collected and analyzed with respect to subsequent decannulation with stoma closure. Results Conventional tracheostomy and cricotracheostomy were performed in 94 and 33 patients, respectively. The most frequent reason for choosing cricotracheostomy was a physiological low-lying larynx (n = 12). After excluding 30 patients who were considered ineligible due to their primary disease, subsequent decannulation with stoma closure was achieved in 35 (46%) of 76 cases with conventional tracheostomy and seven (33%) of 21 cases with cricotracheostomy, showing no significant difference (p = .33). Conclusions/significance Compared with a conventional tracheostomy, cricotracheostomy had an acceptable decannulation outcome. However, it should be emphasized that an appropriate selection of patients is required on considering the advantages of cricotracheostomy.

Culture substrate-associated YAP inactivation underlies chondrogenic differentiation of human induced pluripotent stem cells.

Human induced pluripotent stem cells (hiPSCs) are a promising cell source for the creation of cartilage to treat articular cartilage damage. The molecular mechanisms that translate culture conditions to the chondrogenic differentiation of hiPSCs remain to be analyzed. To analyze the effects of culture substrates, we chondrogenically differentiated hiPSCs on Matrigel or laminin 511‐E8 while holding the composition of the chondrogenic medium constant. Cartilage was formed from hiPSCs on Matrigel, but not on laminin 511‐E8. On Matrigel, the hiPSCs were round and yes‐associated protein (YAP) was inactive. In contrast, on laminin 511‐E8, the hiPSCs were flat and YAP was active. Treating the laminin 511‐E8 hiPSCs in a bioreactor caused cell aggregates, in which the cells were round and YAP was inactive. Subsequent culture of the aggregates in chondrogenic medium resulted in cartilage formation. Transient knockdown of YAP in hiPSCs around the start of chondrogenic differentiation successfully formed cartilage on laminin 511‐E8, suggesting that the activation of YAP is responsible for the failure of cartilage formation from hiPSCs on laminin 511‐E8. Consistently, the addition of YAP inhibitors to laminin 511‐E8 hiPSCs caused partial cartilage formation. This study contributes to identifying the molecules that mediate the effects of culture substrates on the chondrogenic differentiation of hiPSCs as well as to developing clinically applicable chondrogenic differentiation methods.

Osteocyte TGFβ1‑Smad2/3 is positively associated with bone turnover parameters in subchondral bone of advanced osteoarthritis.

Subchondral sclerosis is considered the main characteristic of advanced osteoarthritis, in which bone remodeling mediated by transforming growth factor β (TGFβ) signaling plays an indispensable role in the metabolism. Osteocytes have been identified as pivotal regulators of bone metabolism, due to their mechanosensing and endocrine function. Therefore, the aim of the present study was to investigate the association between osteocyte TGFβ signal and subchondral sclerosis. Knee tibia plateau samples were collected from osteoarthritic patients and divided into three groups: The full cartilage, partial cartilage and full defect groups. Next, changes in osteocyte TGFβ signaling and subchondral bone structure underlying various types of cartilage erosion were detected. Bone mineral density (BMD) assay, histology [hematoxylin and eosin, Safranin-O/Fast green, and tartrate resistant acid phosphatase (TRAP) staining], and reverse transcription-quantitative PCR mainly detected structural alterations, osteogenic and osteo-clastic activity in the cartilage and subchondral bone. The activation of the TGFβ signaling pathway in the subchondral bone was detected by immunohistochemistry and western blotting. The association between osteocyte TGFβ and the regulation of bone metabolism was analyzed by correlation analysis, and further proven in vitro. It was confirmed that the BMD of the subchondral bone increased and underwent sclerosis in the partial cartilage and full defect groups. Additional observation included the thinning of the area of calcified cartilage, in which a bone island formed locally, with subchondral bone plate thickening and increased trabecular bone volume. TRAP staining suggested an increase in bone resorption in subchondral underlying areas of the partial cartilage and full defect groups. Immunohistochemistry results confirmed the activation of osteocyte TGFβ in subchondral underlying areas with severe cartilage erosion. Moreover, osteocyte phosphorylated-Smad2/3 was positively correlated with subchondral BMD, alkaline phosphatase and osteopontin mRNA expression, but it was negatively correlated with TRAP+ cells. Furthermore, it was confirmed in vitro that osteocyte TGFβ signaling could regulate the osteogenic and osteoclastic activity of the mesenchymal stem cells. This study illustrated that osteocyte TGFβ signaling is positively associated with the remodeling of subchondral bone in advanced osteoarthritis and provides a preliminary theoretical basis for further investigations of the role and mechanism of osteocyte TGFβ in subchondral of osteoarthritis.

The effects of cryopreserved human amniotic membrane on fracture healing: Animal study

ObjectiveThe aim of this study was to investigate the effects of human amniotic membrane (HAM) on fracture healing in an animal model. MethodsStandard tibial diaphysial fractures were created in twenty-eight Wistar-Albino rats and treated with intramedullary Kirschner wire (K-wire) and HAM (HAM (+) group) or K-wire only (HAM (–) group). Fracture healing was evaluated by histological analysis, radiologic X-ray views and callus diameter measurements at 3rd and 6th weeks postoperatively. ResultsFracture healing was histologically better in the HAM (+) group and the difference was statistically significant at both 3rd and 6th weeks postoperatively (p < 0.05). The highest histologic scores and entire woven bone formation (Huo Stage 8–9) were obtained at 6th weeks postoperatively in the HAM (+) group. Histological examination also revealed predominant fibrous tissue and partial cartilage formation (Huo Stage 2) at the postoperative 3rd week in the HAM (-) group. Equal amounts of woven bone and cartilage formation (Huo Stage 6–7) were observed at 3rd weeks postoperatively in the HAM (+) group and at 6th weeks postoperatively in the HAM (-) group. The callus diameters were greater in the HAM (+) group and the difference was statistically significant (p < 0.05) at 3rd and 6th weeks postoperatively. Although there was only a statistically significant difference (p < 0.05) at the postoperative 3rd week, radiological scores tended to be higher in the HAM (+) group at both the 3rd and 6th weeks postoperatively. ConclusionHAM is a cheap and easily accessible alternative biological material. HAM may be used to support surgical treatment of fractures, particularly where bone healing is expected to last longer.

The related parameters of cartilage and subchondral bone of femoral condyle in bama minipig

Objective To measure the size and thickness of cartilage in femoral condyle and femoral trochlea of mature bama minipig, thus providing a reference for the doable cartilage defect size and depth. Methods The measuring objects were 10 mature female minipigs, scale was used to measure the size of medial and lateral femoral condyle and femoral trochlea, using needle penetration test method for measuring the thickness of cartilage, microCT scanning was applied to measure the bone mineral density, bone volume fraction and trabecular thickness of subchondral bone. Results The thickness of subchondral bone plate and trabeculae were similar in human and minipig. The width of medial femoral condyle was (16.4±1.2) mm, lateral femoral condyle was (15.11±0.95) mm, the width of trochlear medial facet was (11.1±0.6) mm, the lateral facet was (9.0±0.6) mm, cartilage thickness [medial femoral condyle: (1.5±0.2) mm, lateral femoral condyle: (1.55±0.08) mm, medial trochlear facet: (0.8±0.2) mm, lateral trochlear facet: (0.85±0.03) mm], subchondral bone plate thickness [medial condyle: (207±95) μm, trochlea: (95±36) μm], bone mineral density [medial condyle: (0.72±0.12) g/cm3, trochlea: (0.77±0.15) g/cm3], bone volume fraction [medial condyle: (46±7) %, trochlea: (35±11) %], trabecular thickness [medial condyle: (149±15) μm, trochlea: (141±12) μm]; The arrangement and structure of trabeculae in minipig were consistent with that of human. Conclusion Larger cartilage defect with more than 10 mm in diameter can be made in bama minipig due to its advantage of wider medial femoral condyle. Partial full-thickness cartilage defect can also be made owing to its thicker cartilage. Key words: Femoral condyle size; Trochlear groove size; Thickness of cartilage; MicroCT scanning; Osteochondral injury; Minipig

Partial Costal Cartilage Harvest for Rhinoplasty.

Partial Costal Cartilage Harvest for Rhinoplasty.

Partial Costal Cartilage Harvest for Rhinoplasty.

Partial Costal Cartilage Harvest for Rhinoplasty.

Bone marrow mesenchymal stem cells combined with biomimetic hydrogel for repair of articular cartilage defect in porcine

Objective To investigate the feasibility of bone marrow mesenchymal stem cells (BMSCs) combined with type Ⅱ collagen- hyaluronic acid- oxidized chondroitin sulfate (Col Ⅱ-HA-OCS) biomimetic hydrogel to repair articular cartilage defect in porcine and the role of the transplanted cells played in the process of cartilage repair. Methods A articular cartilage defect model which remaining cartilage calcified zone was created in the knee of Bama minipigs, the autologous BMSCs was used as seeds for transplantation and was labeled by the 5, 6-carboxyfluorescein diacetate succinimidyl ester (CFDA SE). Animals were randomly divided into three groups: Group A (blank group) was left untreated, group B (cell-free biomimetic hydrogel group) was filled with biomimetic hydrogel and group C (BMSCs combined with biomimetic hydrogel group) was filled with the CFDA SE labeled autologous BMSCs combined with biomimetic hydrogel. One month after the operation, BrdU labeled liquid was injected intravenously into the animals 24 h and 48 h before specimens were taken from the executed animals. Partial cartilage repaired tissue in Group C was taken, cryosectioned and stained with DAPI and BrdU immunofluorescence. Confocal laser scanning microscope was used to observe and count the cells. Specimens of the three groups were analyzed through gross observation and histological staining, and scored according to the international cartilage repair society (ICRS) gross morphological score and ICRS histological score. Results Laser scanning confocal microscopy showed (97.3±2.6)% of the cells were derived from the implanted BMSCs in repaired tissue and that the ratio of these cells with proliferative capacity was (76.6±2.5)%. Gross observation suggested most of the cartilage defect areas in Group C were filled with ivory tissue, but those in Group A and B were still obvious depression. Histological staining showed the cartilage defect areas in Group C were filled with cartilage like tissue, which was well integrated with the surrounding normal cartilage, presented a few cartilage lacunas could be seen, and had contents of Col Ⅱ and glycosaminoglycan similar with the adjacent normal cartilage. There was almost no filler in the defect area in Group A. There was little fibrous tissue in the defect area in Group B. ICRS gross score was (8.3±1.0)points in Group C, higher than that in Group A [(0.5±0.6)points] and Group B [(2.3±0.5)points] (P<0.05). ICRS histological score was (10.3±2.4)points in Group C, higher than that in Group A [(0.5±0.6)points] and Group B [(4.5±1.0)points] (P<0.05). Conclusions BMSCs combined with Col Ⅱ-HA-OCS biomimetic hydrogel for repairing porcine articular cartilage defects can achieve satisfactory results. Implanted BMSCs are the main component of the cell composition in the repaired tissue and gradually differentiated into chondrocytes. Key words: Cartilage; Mesenchymal stem cells; Collagen type Ⅱ; Bone regeneration

A Modified Suction-Assisted Technique of Transfer of Diced Cartilage Graft to Carrier Material and Outcome of Direct Injection of Unwrapped Diced Cartilage in Rhinoplasty.

To describe a modified suction-assisted technique (MSAT) of transfer of diced cartilage (DC) graft to a carrier material and to determine the clinical outcome of direct injection of unwrapped diced cartilage (UDC) in rhinoplasty. Department of Plastic Surgery, KEMU, Mayo Hospital, Lahore from February 2011 to January 2015 METHODS:: Forty-seven patients of both genders with types 0 to 3 saddle nose deformity were included. Patients with types 4 and 5 saddle nose deformity, diabetes, hypertension, hepatic or renal disorders were excluded. Open tip rhinoplasty was performed in all patients. Eighth and/or ninth costal cartilage was harvested. Cartilage graft was diced into 1 to 2 mm pieces. The DC graft was transferred to carrier material (1-mL syringe) with MSAT. The UDC was then injected into nose and clinical outcome was determined. Out of 47 patients included in the study 62% were females with mean (standard deviation [SD]) age 22 (4) years. Thirty-four (72%) procedures were primary rhinoplasties while 13 (28%) were secondary rhinoplasties. Mean (SD) carrier material filling time was 12±3 seconds. All operating surgeons involved in study were satisfied with modified suction technique and declared it better than the traditional manual technique of filling the carrier material. Most of the patients were satisfied with their postoperative nasal appearance and complications were minimal. One patient required revision of surgery due to dorsal contour irregularities and another due to partial cartilage absorption at 13 ± 2 months follow-up. Our MSAT of transfer of DC and injection of UDC is simple, easy to perform, reduces operative time and produces acceptable cosmetic outcome as regard patient's satisfaction.

Accuracy of magnetic resonance imaging to detect cartilage loss in severe osteoarthritis of the first carpometacarpal joint: comparison with histological evaluation

BackgroundMagnetic resonance imaging (MRI) is increasingly used for research in hand osteoarthritis, but imaging the thin cartilage layers in the hand joints remains challenging. We therefore assessed the accuracy of MRI in detecting cartilage loss in patients with symptomatic osteoarthritis of the first carpometacarpal (CMC1) joint.MethodsTwelve patients scheduled for trapeziectomy to treat severe symptomatic osteoarthritis of the CMC1 joint underwent a preoperative high resolution 3D spoiled gradient (SPGR) MRI scan. Subsequently, the resected trapezium was evaluated histologically. The sections were scored for cartilage damage severity (Osteoarthritis Research Society International (OARSI) score), and extent of damage (percentage surface area). Each MRI scan was scored for the area of normal cartilage, partial cartilage loss and full cartilage loss. The percentages of the total surface area with any cartilage loss and full-thickness cartilage loss were calculated using MRI and histological evaluation.ResultsMRI and histological evaluation both identified large areas of overall cartilage loss. The median (IQR) surface area of any cartilage loss on MRI was 98% (82–100%), and on histological assessment 96% (87–98%). However, MRI underestimated the extent of full-thickness cartilage loss. The median (IQR) surface area of full-thickness cartilage loss on MRI was 43% (22–70%), and on histological evaluation 79% (67–85%). The difference was caused by a thin layer of high signal on the articulating surface, which was interpreted as damaged cartilage on MRI but which was not identified on histological evaluation.ConclusionsThree-dimensional SPGR MRI of the CMC1 joint demonstrates overall cartilage damage, but underestimates full-thickness cartilage loss in patients with advanced osteoarthritis.

Co-expression of DKK-1 and Sclerostin in Subchondral Bone of the Proximal Femoral Heads from Osteoarthritic Hips

BackgroundOsteoarthritis (OA) is a progressively degenerative joint disease influenced by structural and metabolic factors. There is growing evidence that subchondral bone is involved in both symptomatic and structural progression in OA. The Wnt pathway has been implicated in the progression of OA but the expression and function of the Wnt inhibitors, Dikkopf (DKK-1) and sclerostin (SOST), are unclear.MethodsWe examined the regional distribution of DKK-1 and SOST in subchondral bone of the femoral head using resection specimens following arthroplasty in patients presenting with end-stage OA. Cylindrical cores for immunohistochemistry were taken through midpoint of full thickness cartilage defect, partial cartilage defect, through base of osteophyte and through macroscopically normal cartilage.ResultsSubchondral bone was thickest in cores taken from regions with full cartilage defect and thinnest in cores taken from osteophyte regions. In subchondral bone, expression of both DKK-1 and SOST was observed exclusively in osteocytes. Expression was highest in subchondral bone in cores taken from regions with partial but not full thickness cartilage defects. DKK-1 but not SOST was expressed by chondrocytes in cores with macroscopically normal cartilage.ConclusionThe current study describes the regional cellular distribution of SOST and DKK-1 in hip OA. Expression was highest in the osteocytes in bone underlying partial thickness cartilage defects. It is however not clear if this is a cause or a consequence of alterations in the overlying cartilage. However, it is suggestive of an active remodeling process which might be targeted by disease-modifying agents.

Preliminary investigations on therapy thresholds for laser dosimetry, cryogen spray cooling duration, and treatment cycles for laser cartilage reshaping in the New Zealand white rabbit auricle.

Previous studies have demonstrated the feasibility of laser irradiation (λ = 1.45 μm) in tandem with cryogen spray cooling (CSC) to reshape rabbit auricular cartilage using a total energy density of 14 J/cm(2). The aim of this study was to further explore and identify the dosimetry parameter space for laser output energy, CSC duration, and treatment cycles required to achieve shape change while limiting skin and cartilage injury. Ten New Zealand white rabbits were treated with the 1.45 μm diode laser combined with cryogen spray cooling (Candela Smoothbeam™, Candela Co., Wayland, MA, USA). The ear's central portion was bent around a cylindrical jig and irradiated in consecutive spots of 6 mm diameter (13 or 14 J/cm(2) per spot) along three rows encompassing the bend. CSC was delivered during irradiation in cycles consisting of 25-35 ms. At thin and thick portions of the ear, 4-7 and 6-10 treatment cycles were delivered, respectively. After surgery, ears were examined and splinted for 6 weeks. Treatment parameters resulting in acceptable (grades 1 and 2) and unacceptable (grade 3) skin injuries for thick and thin regions were identified, and shape change was observed. Confocal and histological analysis of cartilage tissue revealed several outcomes correlating to laser dosimetry, CSC duration, and treatment cycles. These outcomes included expansion of cartilage layers (thickening), partial cartilage injuries, and full-thickness cartilage injuries. We determined therapy thresholds for laser output energy, cryogen spray cooling duration, and treatment cycles in the rabbit auricular model. These parameters are a starting point for future clinical procedures aimed at correcting external ear deformities.

Chondrogenic differentiation of bone marrow-derived mesenchymal stem cells induced by acellular cartilage sheets

Acellular cartilage sheets (ACSs) have been used as scaffolds for engineering cartilage with mature chondrocytes. In this study we investigated whether ACSs possess a chondrogenic induction activity that may benefit cartilage engineering with multipotent stem cells. Bone marrow-derived mesenchymal stem cells (BMSCs) isolated from newborn pigs were expanded in vitro and seeded on ACSs that were then stacked layer-by-layer to form BMSC-ACS constructs. Cells seeded on polyglycolic acid/polylactic acid (PGA/PLA) scaffolds served as a control. After 4 weeks of culture with or without additional chondrogenic factors, constructs were subcutaneously implanted into nude mice for another 4 weeks. Cartilage-like tissues were formed after 4 weeks of culture. However, formation of cartilage with a typical lacunar structure was only observed in induced groups. RT-PCR showed that aggrecan, COMP, type II collagen and Sox9 were expressed in all groups except the non-induced BMSC-PGA/PLA group. At 4 weeks post-implantation, cartilage formation was achieved in the induced BMSC-ACS group and partial cartilage formation was achieved in the non-induced BMSC-ACS group, confirmed by safranin O staining, toluidine blue staining and type II collagen immunostaining. In addition, enzyme-linked immunosorbent assay demonstrated the presence of transforming growth factor-β1, insulin-like growth factor-1 and bone morphogenic protein-2 in ACSs. These results indicate that ACSs possess a chondrogenic induction activity that promotes BMSC differentiation.

Direct transplantation of mesenchymal stem cells into the knee joints of Hartley strain guinea pigs with spontaneous osteoarthritis.

IntroductionMesenchymal stem cells (MSCs) can differentiate into various connective tissue cells. Several techniques have been used for the clinical application of MSCs in articular cartilage repair; however, there are many issues associated with the selection of the scaffold material, including its ability to support cell viability and differentiation and its retention and degradation in situ. The application of MSCs via a scaffold also requires a technically demanding surgical procedure. The aim of this study was to test the outcome of intra-articular transplantation of mesenchymal stem cells suspended in hyaluronic acid (HA) in the knee joints of Hartley strain guinea pigs with spontaneous osteoarthritis (OA).MethodsCommercially available human MSCs were cultured, labeled with carboxyfluorescein diacetate succinimidyl ester (CFDA-SE), suspended in either PBS or HA, and injected into the knee joints of 7-month-old animals. The control animals were injected with either PBS or HA alone. The animals were sacrificed at 1, 3, and 5 weeks post transplantation, the knee joints harvested, and fluorescent microscopic analysis was performed. Histological and immunohistochemical analysis were performed at 5 weeks post transplantation.ResultsAt 5 weeks post transplantation, partial cartilage repair was noted in the HA-MSC group but not in the other groups. Examination of CFDA-SE-labeled cells demonstrated migration, differentiation, and proliferation of MSC in the HA-MSC group. There was strong immunostaining for type II collagen around both residual chondrocytes and transplanted MSCs in the OA cartilage.ConclusionThis scaffold-free and technically undemanding technique appears to result in the regeneration of articular cartilage in the spontaneous OA animal model. Although further examination of the long-term effects of transplantation is necessary, the findings suggest that intra-articular injection of HA-MSC mixture is potentially beneficial for OA.

The Split Frontalis Muscle Flap Endoscopically Harvested for Nasal Soft-Tissue Defect Reconstruction

Sir: Postoncologic nasal reconstruction can be a challenge for the plastic surgeon who has to ensure tumor-free margins while recreating the normal appearance in an aesthetically pleasing fashion. The split frontalis muscle flap endoscopically harvested is a practical approach for reconstruction of nasal soft-tissue defects in patients with multiple skin carcinomas of the nasal root that require skeletization and in a selected group of patients in which local flaps or cheek and forehead skin flaps are not available.1 Hydrodissection with tumescent anesthesia is carried out. Then, the endoscopic tools are introduced through a mediofrontal skin access anteriorly to the hairline and two lateral access points in the frontotemporal region (Fig. 1).Fig. 1.: Preoperative appearance in a 73-year-old man affected by two carcinomas beside the root of the nose. In the preoperative markings, the skin access points and the muscle dissection area and its limits are shown.After accurate dissection of the skin flap, the frontalis muscle is detached from the periosteal plane forward to the superior margins of the eyebrow corrugator muscles and divided by a cephalic horizontal and two vertical craniocaudal incisions, turned over 180 degrees on its stalk, tunneled trough the glabella area, laid out on the recipient area, sutured to the healthy skin margins, and grafted with full-thickness skin (Fig. 2).Fig. 2.: The frontal muscle flap has been harvested, turned over on its stalk by 180 degrees, and tunneled trough the glabella.Twenty-nine patients underwent this procedure over a 6-year period. The most common histopathologic diagnosis was basal cell carcinoma. The mean size of the defect was 188 mm2 (range, 89 to 290 mm2). Four patients had partial cartilage resection repaired with conchal cartilage, and the intranasal lining was always preserved. In 22 patients (80 percent), the defects were limited to the upper two-thirds of the nasal pyramid, and the success rate was 100 percent. The mean follow-up was 17 months (range, 8 to 36 months). This technique is indicated in patients with multiple skin carcinomas of the root of the nose requiring skeletization; patients with multiple precancerous lesions or previous scars on the forehead area for which the traditional forehead skin flaps cannot be used; and patients who refuse evident scars on the forehead area or on the face, a condition that should not be underestimated. Therefore, the split frontalis muscle flap has the following advantages: its arc of rotation does not cause any distortion of the medial eyebrow, a probable condition using forehead skin flaps1,2; it is a single-stage procedure; and satisfactory morphologic-aesthetic results can be achieved, with minimal scarring at the donor site and stable outcomes.3 The split frontalis muscle flap endoscopically harvested can be considered an adequate and practical approach for nasal soft-tissue defect reconstruction. Luca Gentile, M.D. Michele Di Candia, M.D. Christian Pascone, M.D. Vincenzo Bucaria, M.D. Michele Pascone, M.D. Department of Plastic and Reconstructive Surgery Policlinico University Hospital Bari, Italy PATIENT CONSENT The patient provided written consent for the use of his image.