Viability of cultured human nasal septum chondrocytes after crushing

OBJECTIVE: To investigate how different degrees of crushing affect the viability of human nasal septum chondrocytes in adherent cell cultures. METHODS: Cartilage grafts were harvested from the nasal septa of 15 patients who underwent submucosal resection. Five cartilage pieces were prepared from each specimen as follows: the cartilage was left intact, slightly crushed, moderately crushed, significantly crushed, or severely crushed. Chondrocytes were isolated for trypan blue dye exclusion testing, and the numbers of viable cells were determined at 1, 2, 3, and 10 days after culturing. Comparisons were made among the groups. RESULTS: The day 1 viability rates for the intact, slightly crushed, moderately crushed, significantly crushed, and severely crushed cartilage preparations were 96%, 92%, 82%, 72%, and 54%, respectively. The corresponding rates on day 10 were 93%, 90%, 84%, 75%, and 68%. CONCLUSIONS: The viability and proliferative capacity of crushed human septal cartilage depend on the degree of crushing sustained. Slightly or moderately crushed cartilage grafts show good chondrocyte viability and proliferation and are valuable for fashioning soft nasal contours, filling defects, and concealing dorsal irregularities. However, significant or severe crushing reduces chondrocyte viability and proliferation and may result in unpredictable degrees of graft volume loss.     

Chin augmentation using diced cartilage

Eight patients with microgenia have undergone augmentation with diced nasal cartilage. Cartilage grafts were harvested from the nose during rhinoplasty. These grafts were cut into 0.5 to 1.0 mm pieces using a #11 blade and were wrapped in one layer of Surgicel (oxidized regenerated cellulose). This cartilage mass was inserted into the chin pocket. All patients underwent clinical evaluation, magnetic resonance imaging (MRI), and photography. These investigations showed that diced cartilage grafts maintained 75% of their dimensions at six months after implantation. The follow-up period was 12 months, and the aesthetic results were satisfactory. Received: 5 May 1997 / Accepted: 21 August 1997     

Radiologic and Histologic Assessment of Diced Cartilage Grafts for Cranial Bone Defects of Rabbits: An Experimental Study

This study was performed to experimentally evaluate the viability and coverage of diced cartilage grafts for cranial defects. Biparietal bone defects were prepared in each of 20 rabbits. Otogenous bone grafts were fixed to one side, whereas cartilage grafts taken from the right ear, diced, and wrapped with oxidized regenerated cellulose (Surgicel) were placed on other side. Parenchymal impression, contour, and ossification of all grafts in the 16 rabbits surviving after 8 weeks were evaluated with computed tomography and magnetic resonance imaging. The existence of ossification was examined pathologically. Parenchymal impression was significantly more frequent in bone grafts than in cartilage grafts (p < 0.05). This difference probably is attributable to the application technique. There was no significant radiographic difference in other parameters between the two groups. No significant difference in ossification was found. In conclusion, ossification was seen radiologically and pathologically in diced cartilage grafts. Because of autogenicity, ease of shaping, absence of postoperative warping, reduced resorption rates, and inherent viability and ossification properties, the authors suggest that diced cartilage grafts may be an alternative material for cranial defects, especially for frontal cranial reconstruction in which deformities may cause aesthetic and functional disabilities. The authors believe that further long-term studies also are needed.     

Study of rabbit septal cartilage grafts placed on the nasal dorsum

OBJECTIVE: To compare the reabsorption characteristics of fresh septal cartilage autografts, preserved homografts, and preserved autografts in the nasal dorsum of rabbits. METHODS: Rabbit nasal dorsum cartilage grafts were placed in 3 groups. The first group used fresh autologous cartilage; the second group, alcohol-preserved homologous cartilage; and the third group, alcohol-preserved autologous cartilage. Each rabbit received 2 grafts, one crushed and another noncrushed. After 16 weeks, the grafts were removed for analysis. RESULTS: No graft calcification occurred in any group. Chondrogenesis was observed in all groups. The fresh autograft group had the best results in the evaluation of the area of graft recovered and chondrocyte viability. The preserved autologous and homologous grafts did not differ in relation to any of the variables analyzed. Crushed grafts had inferior results in the area of graft recovered and chondrocyte viability compared with the noncrushed forms. No significant difference among the 3 groups was noted in the thickness of the fibrous capsule that developed around the graft. CONCLUSIONS: The fresh cartilage autograft was superior to the crushed and uncrushed preserved homografts and autografts; both types of preserved grafts had equivalent histological results. The uncrushed forms were superior to the crushed forms.     

提高自体软骨移植物活性的研究进展

软骨移植物主要包括自体软骨、同种异体软骨、冷冻同种胚胎软骨、骨膜、软骨膜和生物材料等。但软骨移植存在许多缺陷,如供区继发性病变、进行性供区结构异常、移植物弯曲变形,移植物吸收与存活等问题。本文就提高自体软骨移植物活性的方法,包括软骨碎片或颗粒移植和包裹技术等进行综述。     

Crushed cartilage grafts for concealing irregularities in rhinoplasty

OBJECTIVE: To assess the clinical outcome of crushed cartilage grafts used to conceal contour irregularities in rhinoplasty. METHODS: We reviewed the medical records of 462 patients in whom crushed autogenous cartilage grafts were used, selected from a total of 669 patients in whom rhinoplasty procedures were performed at our institution between June 1, 1999, and June 1, 2006. The grafts were used as slightly, moderately, significantly, or severely crushed. RESULTS: Eight hundred nine cartilage grafts (41 slightly crushed grafts [5%], 650 moderately crushed grafts [80%], and 118 significantly crushed grafts [15%]) were used in 462 patients. Resorption occurred in 11 of the 462 patients (2.4%). All of the resorbed grafts (6 moderately crushed grafts and 5 significantly crushed grafts) had been placed in the dorsal area. The resorption rate of those grafts was lower in the moderately crushed cartilage grafts (6 of 284 grafts [2.1%]) than in the significantly crushed grafts (5 of 38 grafts [13.1%]). There was no resorption of slightly crushed grafts. CONCLUSIONS: The degree of crushing applied is important for long-term clinical outcome of autogenous crushed cartilage grafts. Slight or moderate crushing of cartilage creates an outstanding graft material for concealing irregularities and provides both excellent long-term clinical outcome and predictable esthetic results.     

Radiologic and histological evaluation of otogenic sliced cartilage grafts at the tip of the chin of rabbits: an experimental study.

OBJECTIVES: Cartilage grafts have been commonly used in plastic and reconstructive surgery applications for many different goals, such as auricular reconstruction and rhinoplasty. The use of autologous cartilage is ideal for many reasons. An attempt was made to produce an experimental animal model to test the efficacy of otogenic Surgicel-wrapped sliced cartilage. METHODS: In this experimental study, cartilage grafts were harvested from rabbits' ears. These grafts were cut in pieces of 0.5 mm to 1 mm using a no. 11 blade. This cartilage mass was wrapped in one layer of Surgicel (oxidized regenerated cellulose) and inserted in the chin of the rabbits. MR analyses were made at 1 week and 6 months and histological analyses were made at 6 months. RESULTS: Cartilage grafts maintained approximately 80% of their dimensions in MRI. The proportion of necrosis was between 30% and 50% and the proportion of resorption was approximately 20% in the histological studies.     

Dorsal nasal augmentation with "open sandwich" graft consisting of conchal cartilage and retroauricular fascia

Background: Augmenting the nasal dorsum with conchal grafts can cause visible irregularities over time due to the morphological qualities of that material. Objectives: This study describes the senior authors' technique of dorsal nasal augmentation with chondrofascial "open sandwich" grafts consisting of pieces of conchal cartilage and retroauricular fascia. The authors assess the efficiency and reliability of this graft in nasal dorsal augmentation. Methods: The authors retrospectively reviewed the cases of 19 patients who underwent dorsal augmentation rhinoplasty with chondrofascial grafts. Both cartilage and fascia were harvested through the same incision in the retroauricular sulcus. The conchal graft was cut in 2 to 4 pieces and slightly crushed with tissue forceps. The pieces of cartilage were arranged and fixed to the fascia in different patterns according to the nasal dorsum contour. Results: The follow-up period ranged from 12 to 35 months in 16 patients who qualified for inclusion in the final data. The maximal thickness of the chondrofascial graft was 4.5 mm. There were no major complications in the recipient area, except 1 case of undercorrection. There were 2 complications in the donor area. In 1 case, a hematoma was treated conservatively. In another case, a strip of skin necrosis in the conchal area occurred and was treated by excision and direct suture with satisfactory resolution. Conclusions: The autologous chondrofascial graft is appropriate for slight to mild dorsal nasal augmentation. The method, as with most rhinoplasty techniques, requires careful and judicious preoperative examination, planning, and execution. The postoperative scar is inconspicuous and the donor site morbidity is minimal. Level of Evidence: 4.     

Secondary rhinoplasty: management of the overresected dorsum

Any discussion of grafting the dorsum in secondary rhinoplasty must take into account the different indications (aesthetic, augmentation, and structure) as well as recent changes in materials and techniques (fascia, diced cartilage). We have placed solid dorsal grafts with diced cartilage grafts either as an isolated diced cartilage graft in fascia graft or as the aesthetic dorsal contour layer of a composite reconstruction. The rational for this profound change in selection and indication of dorsal grafts for revising the overresected dorsum will become clear as the various alternative materials and techniques are analyzed. Currently, we only employ autogenous tissues.     

Diced ear cartilage with perichondrial attachment in rhinoplasty: a new concept

Background: Diced cartilage is a valuable material that has recently been added to the graft options in rhinoplasty. Shaping, fixation, and resorption are the main concerns with this material. Perichondrially attached diced conchal cartilage may be a new possibility to solve some of these problems. Objectives: The authors evaluate the outcome of perichondrially attached diced cartilage in a rabbit model and compare the results with injectable cartilage grafting. Methods: Ear cartilage was removed from 1 auricle in each of the 16 rabbits included in this study; samples were divided in 2 pieces. After precise weighing, both segments were diced. The perichondrium was left attached to 1 of the pieces. Both segments were inserted in 2 separate pockets in the dorsum of the animal. After a 3-month period, both samples were removed and measured for growth/resorption. Results: At the beginning of this study, the difference in weight between groups was statistically insignificant (P = .213), but 3 months after insertion, significant growth was observed in the perichondrial group (P = .019). Conclusions: The vascularization and significant growth in weight of the perichondrially attached diced cartilage samples are evidence of the viability of this material. The structural integrity and solid framework afforded by this option suggest that the material should be used more frequently in nasoskeletal augmentation.     

Chondrocyte viability in fresh and frozen large human osteochondral allografts: effect of cryoprotective agents

Chondrocyte survival is a major goal for the effective storage and clinical performance of human osteochondral allografts. The majority of animal and human cryopreservation studies conducted so far have been performed in small osteochondral cylinders. Using human tibial plateaus as a model for large osteochondral pieces, this work sought to evaluate the cryoprotective efficiency of glycerol and dimethylsulfoxide (DMSO), and to identify cryopreservation conditions suitable for use in tissue banks. Human tibial plateaus harvested from 7 cadaveric tissue donors were incubated in the presence or absence of cryoprotective agents (CPA): 10% or 15% glycerol and 10% DMSO in a Ham F-12 nutrient mixture. Chondrocyte viability was assessed immediately after thawing, using the MTT reduction assay and a fluorescence microscopic method. The tibial plateaus frozen in the absence of CPA showed a significant decrease in chondrocyte viability. The use of CPA significantly increased chondrocyte viability compared with cartilage frozen without CPA (nearly 50% versus 80% living chondrocytes with 10% glycerol versus 10% DMSO, respectively) relative to that in fresh cartilage. In this regard, 10% DMSO was slightly more effective than either 10% or 15% glycerol, eliciting the recovery of approximately 15% relative to the living chondrocyte content in fresh cartilage. In all conditions, fluorescence microscopic studies showed that surviving chondrocytes were restricted to the superficial cartilage layer. Human tibial plateaus seemed to be a good experimental model to establish cryopreservation methods applicable to large human osteochondral pieces in tissue banks.     

The Fate of Diced Cartilage Grafts of Traumatized Versus Nontraumatized Origin

Background Diced cartilage grafts have long been used in rhinoplasty. Along with their various reported advantages, they also have some disadvantages. The irregular resorption rate of the engrafted mass is one of the major issues noted with diced cartilage grafts. An explanation for the unpredictable resorption rate has not yet been elucidated. This study aimed to determine the role of traumatized versus nontraumatized cartilage as the source of diced cartilage grafts. Methods This study included the noses of 32 patients (19 traumatized noses and 13 nontraumatized noses) who underwent surgery using Surgicel-wrapped diced cartilage grafts. Results The most remarkable result noted in this study was that a Surgicel-wrapped diced cartilage graft, if prepared from traumatized cartilage (in 19 patients), failed to maintain a stable long-term volume. Partial volume loss was noted in 100% of these patients. However, the rate of this partial resorption was different for every individual and could not be predicted. The highest retention of cartilage graft volume was seen primarily over the nasal osseocartilaginous junction. In nontraumatized patients, however, the engrafted mass maintained long-term volume stability. These patients evidenced no visible external irregularities, and only a few very slight imperfections were noted with finger palpation. Conclusion Diced cartilage of traumatic origin is not recommended for any purpose. In such cases, the authors’ engrafting algorithm consists of autobone or ear conchal cartilage grafts for dorsal augmentation, columellar struts from the nontraumatized part of the septum, and spreader grafts from the nontraumatized part of the septum or ear concha.     

Immunological response against allogeneic chondrocytes transplanted into joint surface defects in rats

Rat chondrocytes isolated from the articular-epiphyseal cartilage complex were transplanted into defects prepared in articular cartilage and subchondral bone. Transplants were taken for examination after 3 and 8 wk. Cartilage formed by syngeneic chondrocytes did not evoke formation of infiltrations. Contrary to that, in the vicinity of cartilage produced by allogeneic chondrocytes numerous infiltrating cells were present and cartilage resorption could be observed. Cyclosporine-A (CsA) treatment of recipients of allogeneic chondrocytes only partially suppressed accumulation of infiltrating cells and matrix resorption. Antichondrocyte immune response of chondrocyte graft recipients was studied by evaluation of spleen mononuclear cells (SMC) stimulation in mixed splenocytechondrocyte cultures and by evaluation of antichondrocyte cytotoxic antibodies. No difference in stimulation of SMC from intact rats by syngeneic and allogeneic chondrocytes was observed. Stimulation by allogeneic chondrocytes was slightly but significantly higher in recipients of syngeneic grafts. SMC of allogenic chondrocyte recipients were strongly stimulated by allogeneic chondrocytes. This response was absent in recipients treated with CsA. Spontaneous antichondrocyte cytotoxic antibody activity was detected in intact rats and in recipients of syngeneic grafts. In recipients of allogeneic chondrocytes the antibody response against allogeneic chondrocytes was raised but was statistically not significant owing to the considerable variation in the level of spontaneously occurring antichondrocyte antibodies.     

The use of diced cartilage as a testicular replacement in rabbits

Silicone prostheses have primarily been used for cosmesis after orchiectomy, but complications have been reported. In this experimental study, diced cartilage graft has been used for testicular replacement in rabbits. Although later reduction of the volume was seen in the MRI studies, diced cartilage grafts can be used for testicular prostheses but overcorrection of the volume seems to be desirable. Received: 21 February 1997 / Accepted: 2 September 1997     

Cartilage graft resorption: An animal model

Background: Autologous cartilage grafts have become an integral part of aesthetic and reconstructive plastic surgery. However, little objective information is available about the actual quantitative resorption of cartilage. Objective: This study sought to objectively quantify and compare the resorption of auricular and costal cartilage in an animal model over a 1-year time period. Methods: Autologous auricular and costal cartilage was harvested from New Zealand white rabbits. Each of the auricular and costal cartilage specimens was divided into 6 pieces. Two of the 6 pieces from each donor site were crushed, 2 were carved, and 2 were left untouched. One set of crushed, carved, and untouched cartilage from each site (auricular and costal) was placed into the subcutaneous tissues of the nasal dorsum, and a second set from each site was placed in the occiput as a control. In all, 12 pieces were placed into each of 7 rabbits, for a total of 84 grafts. Before placement, the mass and volume of each graft were measured through use of an analytic balance. After 1 year, the pieces were harvested and the mass and volume were measured again. Results: The resorption of ear cartilage was determined to be 16.4% ± 4.8% (P < .0001). For the costal cartilage group, an overall slight weight gain of 2.79% ± 8.61% (P = .1032) was observed; this was not statistically significant. No statistically significant difference in resorption of cartilage occurred between the untouched (native), carved, and crushed cartilage. The reduction in cartilage volume approximately mirrored the observed weight reductions. No difference in volume reduction was observed between the nasal snout groups and the occipital controls. Conclusions: This preliminary animal study found that ear cartilage resorbs more than costal cartilage and that carving does not affect the amount of resorption.     

Comparison of AlloDerm, fat, fascia, cartilage, and dermal grafts in rabbits

OBJECTIVE: To compare various graft materials in the rabbit model, including autologous cartilage, dermal tissue, fat, and AlloDerm (a cadaver-derived material). METHODS: Twenty-five New Zealand white rabbits were used. Equally sized autogenous (fat, fascia, cartilage, and dermal) grafts and AlloDerm were implanted into subcutaneous dorsal pockets on the rabbits. Animals were killed 1, 2, 3, and 4 months after surgery. The grafts were examined microscopically for thickness, resorption, fibrosis, neovascularization, inflammation, eosinophilia, and the presence of multinucleated giant cells or microcysts. RESULTS: The cartilage grafts revealed excellent viability with no resorption. The fascial grafts showed negligible volume loss. The dermal grafts developed epidermoid cysts. The AlloDerm grafts demonstrated graft thickening at 1 month and total resorption at 3 and 4 months. The fat grafts demonstrated 30% to 60% partial resorption. CONCLUSIONS: The major disadvantage of using an autogenous fat graft was partial resorption, whereas cyst formation was observed with dermal grafts. AlloDerm caused tissue reaction and resorption. The best graft material was cartilage, with a low absorption rate, good biocompatibility, and minimal tissue reaction or fibrosis, followed by fascia, with a minimal shrinkage capacity and tissue reaction.     

Effect of impact on chondrocyte viability during insertion of human osteochondral grafts

BACKGROUND: Osteochondral grafts, used to treat chondral and osteochondral defects, require high insertional forces that may affect the viability of chondrocytes in the graft. The objectives of this study were to (1) measure the loading impact during insertion of osteochondral grafts, (2) evaluate the effect of insertional loading on chondrocyte viability, and (3) assess this effect on chondrocyte apoptosis and activation of caspase-3. METHODS: The distal parts of twelve fresh femora from six adult human cadavers were harvested within seventy-two hours after the death of the donor. From each femur, four 15-mm-diameter cylindrical osteochondral grafts were isolated; two of these grafts (a total of twenty-four grafts in the study) were transplanted with standard impact insertion into recipient sockets in the other condyle of the ipsilateral femur. The other two grafts served as unloaded controls. Loads were measured during the insertion of ten of the twenty-four transplanted grafts. Full-thickness cartilage disks were then removed from the grafts, incubated for up to forty-eight hours, and analyzed for cell viability, TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling)-positive reactivity, and caspase-3 activation, each as a function of the depth from the articular surface. RESULTS: The insertion of an osteochondral graft was characterized, on the average (and standard deviation), by 10 +/- 4 impacts, each generating 2.4 +/- 0.9 kN of load and 13.3 +/- 4.9 MPa of stress for a duration of 0.57 +/- 0.13 ms with a 0.62 +/- 0.25 N.s impulse. Impact insertion increased cell death in the superficial 500 mum to 21% at one hour (p < 0.001) and 47% at forty-eight hours (p < 0.001) and also increased cell death in deeper layers at forty-eight hours. Some cell death was due to apoptosis, as indicated by an increase in caspase-3 activation at eight hours (p < 0.01) and TUNEL-positive cells at forty-eight hours (p < 0.05) in the superficial 500 mum of impacted cartilage. CONCLUSIONS: Impact insertion of osteochondral grafts generates damaging loads that cause chondrocyte death, particularly in the superficial zone, mainly as a result of apoptosis mediated by the activation of caspases. CLINICAL RELEVANCE: Chondrocyte death that occurs during impact insertion of osteochondral grafts may lead to compromised function. Understanding the mechanisms and consequences of such impact loading may provide insights into potential therapeutic interventions, or lead to changes in the insertion technique, to decrease the cell injury associated with impact loading.     

Cryopreserved tracheal grafts: a review of the literature.

Cryopreserved tracheal grafts have been used in several experimental models of long segment replacement. The clinical application of the procedure has been limited due to the fact that contradictory results have been reported. The purpose of this article is to present a review of the literature on tracheal cryopreservation. Despite the fact that most authors indicate that cryopreserved tracheal allografts retain viability and have a low immunological response, though they continue to function after transplantation with good epithelialization and patency, cryopreservation leads to significant damage to cartilage, the degree of which is based on the freezing-storage methods that affect the function and durability of a graft. The long-term storage of cartilage must therefore be investigated in more detail in basic research models of cartilage viability: the evaluation of chondrocyte apoptosis, and the use of different solutions for tracheal cryopreservation other than RPMI-1640, Dulbecco's modified Eagle's, Eurocollins, and TC-199. Furthermore, problems that involve improving the blood supply to the graft after extensive resection and immunosuppression must be resolved before tracheal cryopreservation can become a clinically established method for tracheal grafts.     

In-vitro-Studie zum Einfluss von Fibrin in Knorpelkonstrukten auf der Basis von PGA-Vliesstoffen

BACKGROUND: The matrix component in autologous chondrocyte implantation plays an important role. In this study the influence of an additional fibrin component in cartilage constructs based on polyglycolide polymers (PGA) was investigated. METHODS: Human chondrocytes of femoral heads were isolated and cultured using a serum-free technique. The cells were seeded on PGA-91 scaffolds with and without an additional fibrin component; the constructs were cultured for 2 weeks in vitro. Besides cell viability, DNA content, pH, aggrecan production, mRNA expression of aggrecan, and collagen types I and II were determined by real-time PCR. Furthermore, cartilage grafts were histologically analyzed. RESULTS: All constructs contained viable, metabolically active cells in the investigated time period. There was no cell proliferation within the graft, and the DNA content was decreased over time. The pH level constantly remained within a physiologic range. The Alcian blue staining of the constructs showed the homogeneous cell distribution and a cell-associated proteoglycan production. Aggrecan concentration in the supernatants of fibrin-containing constructs was significantly lower compared to fibrin-free grafts (-24%), a result that correlated with diminished aggrecan mRNA expression (-80%). mRNA expression of collagen type II increased in the fibrin-free constructs over time and was 57% higher than in the fibrin-containing grafts. The immunohistochemical detection of collagen type II was possible in all constructs. CONCLUSION: Cartilage constructs based on carbohydrate matrices are suitable for matrix-associated chondrocyte implantation. The results of this study suggest a partially inhibitory effect of an additional fibrin component in PGA constructs for chondrogenic differentiation.     

Value of autologous chondrocyte transplantation in experimental cartilage defects reconstruction. Part IV--Microscopic analysis of repair tissue degenerative changes (cellularity and signs of necrosis)]

Articular cartilage cells are immersed in semi-solid matrix and isolated from the rest of the body because of lack of nervous fibres, and blood and lymphatic vessels. Trauma and aging processes result in cartilage ultrastructure disorders. Those changes leads to progressive decreasing of durability and rigidity of cartilage. Research on articular cartilage reconstruction focuses on, among other things, reaching by newly formed tissue optimal amount of vital cells. The aim of this part of the study was microscopic evaluation of repair tissue degenerative changes (cellularity and signs of necrosis). MATERIAL AND METHODS: Repair of partial thickness cartilage defect (III tertiary grade) on distal femur joint surface was evaluated (25 adolescent rabbits). Procedures were performed in two groups: I--autologous chondrocyte transplantation under periosteal flap, II--periosteal graft. Chondrocytes were isolated from the cartilage specimens by enzymatic digestion and cultured in vitro. The follow-up periods were established at 4, 8 and 12 weeks. Repair tissue was evaluated microscopically according to modified O'Driscoll scale. RESULTS: Repair tissue cellularity. In group I (with chondrocytes), 4 weeks after the procedure tissue of high cellularity was formed, corresponding in amount of cells to the structure of early differentiated hyaline-like cartilage. Amount of cells slightly decreased with time, as it occurs in maturing cartilage. In group II (without chondrocytes), 4 weeks after the procedure the repair tissue was characterized by small amount of cells, which was decreasing with time. Signs of necrosis. In group I, 4, 8 and 12 weeks after the procedure moderate intensity of necrotic signs was observed. In group II, significant intensity of necrosis signs in all observation periods was observed. CONCLUSION: Obtained results indicate, that autologous chondrocyte transplantation in treatment of partial thickness cartilage defects effects with forming tissue of high cellularity, not degenerating with time, much better as compared to untreated defect.