The Role of Bone Marrow Aspirate Concentrate for the Treatment of Focal Chondral Lesions of the Knee: A Systematic Review and Critical Analysis of Animal and Clinical Studies.

PURPOSE: To summarize currently available data regarding the use of bone marrow aspirate concentrate (BMAC) for the treatment of focal chondral lesions of the knee in experimental animal models and human clinical studies. METHODS: A systematic review searching for the terms "(bone marrow)" AND "(aspirate OR concentrate)" AND "(cartilage OR chondral OR osteochondral)" was performed in the databases PubMed, Cochrane Central Register of Controlled Trials, and Google Scholar regarding the use of BMAC for the treatment of focal chondral lesions of the knee. The inclusion criteria were animal and clinical studies published in English that used autologous BMAC to treat focal chondral defects of the knee. We excluded studies that evaluated nonconcentrated preparations of bone marrow aspirate or preparations that were culture expanded. RESULTS: A total of 23 studies were included: 10 studies performed in animal models and 13 human clinical studies. Animal studies showed inconsistent outcomes regarding the efficacy of BMAC for the treatment of chondral or osteochondral lesions, assessed by gross morphology, second-look arthroscopy, magnetic resonance imaging, histology, immunohistochemistry, mechanical testing, and micro-tomography. Chondral defect filling was achieved with fibrocartilage or "hyaline-like" cartilage. Cells present in BMAC did not meet the criteria to be characterized as mesenchymal stem cells according to the International Society for Cell Therapy because freshly isolated cells failed to show tri-lineage differentiation. Overall, all clinical studies, independent of the study group or level of evidence, reported improved clinical outcomes and higher macroscopic, magnetic resonance imaging, and histology scores. Comparative trials favored BMAC over microfracture and reported equivalent outcomes between BMAC and matrix-induced autologous chondrocyte implantation. However, clinical studies were scant and showed low scientific rigor, poor methodologic quality, and low levels of evidence on average. CONCLUSIONS: Although clinical success in short-term and midterm applications has been suggested for the application of BMAC for the restoration of cartilage defects in lesions of the knee, current study designs are generally of low scientific rigor. In addition, clinical applications of this technology in animal model investigations have shown inconsistent outcomes. Thus, clinicians should apply this technology cautiously. LEVEL OF EVIDENCE: Level IV, systematic review of Level II, III, and IV evidence studies.

Return to Sport and Sports-Specific Outcomes After Osteochondral Allograft Transplantation in the Knee: A Systematic Review of Studies With at Least 2 Years' Mean Follow-Up.

PURPOSE: To report current data on return-to-sport rates and sports-specific patient-reported outcomes after osteochondral allograft (OCA) transplantation for cartilage defects of the knee. METHODS: We performed a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines that included studies from 1975 to 2018 with a minimum 2-year mean follow-up that reported return-to-sport rates or sports-specific patient-reported outcomes. Outcomes, reoperations, and complications were provided in table format, and a subjective analysis was performed. RESULTS: This review included 13 studies with 772 patients who underwent OCA transplantation at a mean of 24 to 91 months' follow-up. The return-to-sport rate ranged from 75% to 82%. For patient-reported outcomes, the Knee Injury and Osteoarthritis Score Sport increased in 4 studies, the Tegner activity scale score increased in 3 studies but decreased in 1, and the Marx activity scale score increased in 1 study but decreased in 2. Studies reporting improvements in the Cincinnati Knee Score and Knee Injury and Osteoarthritis Score Sport reached the minimal clinically important difference. The reoperation rate was high (ranging from 34% to 53% in more than half of studies), with reoperations primarily performed for loose body removal or debridement. CONCLUSIONS: This systematic review of 13 studies suggests that OCA transplantation for cartilage defects allows most athletes to return to sport (range, 75%-82%). Most studies reported improvements in sports-specific patient-reported outcomes at follow-up and reached the minimal clinically important difference. However, the reoperation rate was high in several studies, with a large percentage of patients requiring loose body removal or debridement. The long-term survival of the allografts is largely unknown, but this study suggests OCA transplantation consistently improves function in athletes with chondral injuries. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Cartilage regeneration using a novel autologous growth factors-based matrix for full-thickness defects in sheep.

PURPOSE: To investigate the chondrogenic-regenerative properties of a novel autologous-made matrix composed of hyaline cartilage chips combined with a growth factors-based clot for full-thickness defects in sheep. METHODS: A full-thickness, 8-mm diameter cartilage defect was created in the weight-bearing area of the medial femoral condyle in 6 sheep. Treatment consisted of surgical implantation of an autologous-based matrix of hyaline cartilage chips combined with a clot of plasma poor in platelets and intraarticular injection of plasma rich in growth factors. Outcome measures at 1, 3 and 6 months included macroscopic International Cartilage Repair Society (ICRS) score, histological and immunohistochemical analysis for collagen expression, and transmission electron microscopy study. RESULTS: The 6-month macroscopic evaluation showed nearly normal (11.1 ± 0.7) cartilage repair assessment. The ICRS score was significantly higher at 6 months compared to 3 months (5.5 ± 1.3; p < 0.0001) and 1 (1.1 ± 0.4; p < 0.0001) month. At 6 months, hyaline cartilage tissue filling the defect was observed with adequate integration of the regenerated cartilage at the surrounding healthy cartilage margin. At 6 months, mature chondrons and cartilage matrix contained collagen fibers with masked fibrillary structure, and the expression of collagen in the newly formed cartilage was similar in intensity and distribution pattern compared to the healthy adjacent cartilage. CONCLUSIONS: This novel treatment enhanced chondrogenesis and regenerated hyaline cartilage at 6 months with nearly normal macroscopic ICRS assessment. Histological analysis showed equivalent structure to mature cartilage tissue in the defect and a collagen expression pattern in the newly formed cartilage similar to that found in adjacent healthy articular cartilage. The present technique may have clinical application for chondral injuries in humans because this procedure is cheap (no need for allograft, or expensive instrumentation/biomaterials/techniques), easy and fast-performing through a small arthrotomy, and safe (no rejection possibility because the patients' own tissue, cells, and plasma are used).

Is There Any Correlation Between Short-Term MRI And Mid-Term Clinical Resultsin Patients Undergoing An Osteochondral Autograft In The Knee?

Thirthy three patients (mean age 32 years) undergoing OA were retrospectively evaluated. All patients had MRI at mean 6.6 months. Lysholm, International Knee Documentation Committee (IKDC), and Tegner scores. The aim is to evaluate Magnetic Resonance Imaging (MRI) in patients who underwent an Osteochondal Autograft (OA) and correlate them with their clinical results-evaluated at mean followup of 28 months (12-88). Tegner Pre-operatively: 6.6, Post-operative: 7.4 (p<0.001). Mean Lysholm: 87, mean IKDC: 86. MRI: complete filling of the lesion in 25 (75.7%) patients, complete integration of the graft in 5 (15.1%) and intact repair tissue in 22 (66.6%. Positive correlation between the degree of repair and filling of the defect and higher Lysholm and IKDC (p<0.05). There is a minor association between short-term MRI and mid-term clinical results after an OA being the degree of repair and filling of the chondral defect the only parameters correlated with patient´s evolution.

Mosaicplasty for the treatment of a large traumatic osteochondral femoral head lesion: a case report with 2 year follow-up and review of the literature.

Different joint-preserving techniques have been described for the treatment of traumatic osteochondral lesions of the femoral head especially in young active patients. Mosaicplasty with autologous transplantation of osteochondral cylinders is an established surgical technique in the knee. Little evidence, however, exists for the treatment of osteochondral lesions in the hip using this technique. Here, we report on the result of treatment of a traumatic 5 cm(2) osteochondral lesion of the femoral head in a young patient treated with mosaicplasty. Grafts were taken from the ipsilateral knee. After 2 years, the outcome was satisfactory with partial return to previous activity level.

Steroid-induced femoral head osteonecrosis in immune thrombocytopenia treatment with osteochondral autograft transplantation.

Osteonecrosis of the femoral head is a devastating complication of steroid administration and has rarely been observed in the treatment of immune thrombocytopenia. The treatment of osteochondral defects in advanced stages of avascular necrosis (AVN), characterized by collapse of the subchondral bone, remains an unsolved burden in orthopedic surgery. In this report, we present a case of a 19-year-old female that was admitted in the Emergency Department with walking disability and painful hip joint movement due to steroid-induced femoral head osteonecrosis. Two years before she was diagnosed with immune thrombocytopenia, for which she received pulse steroid therapy with high dose of dexamethasone and underwent a splenectomy. This case report is the first to describe the use of osteochondral autograft transplantation as a treatment of steroid-induced AVN of the femoral head due to immune thrombocytopenia at the age of 19 years with very good clinical and radiological results 3 years postoperatively.

Talocalcaneal Joint Middle Facet Coalition Resection With Interposition of a Juvenile Hyaline Cartilage Graft.

Talocalcaneal joint middle facet coalition is the most common tarsal coalition, occurring in ≤2% of the population. Fewer than 50% of involved feet obtain lasting relief of symptoms after nonoperative treatment, and surgical intervention is commonly used to relieve symptoms, increase the range of motion, improve function, reconstruct concomitant pes planovalgus, and prevent future arthrosis from occurring at the surrounding joints. Several approaches to surgical intervention are available for patients with middle facet coalitions, ranging from resection to hindfoot arthrodesis. We present a series of 4 cases, in 3 adolescent patients, of talocalcaneal joint middle facet coalition resection with interposition of a particulate juvenile hyaline cartilaginous allograft (DeNovo(®) NT Natural Tissue Graft, Zimmer, Inc., Warsaw, IN). With a mean follow-up period of 42.8 ± 2.9 (range 41 to 47) months, the 3 adolescent patients in the present series were doing well with improved subtalar joint motion and decreased pain, and 1 foot showed no bony regrowth on a follow-up computed tomography scan. The use of a particulate juvenile hyaline cartilaginous allograft as interposition material after talocalcaneal middle facet coalition resection combined with adjunct procedures to address concomitant pes planovalgus resulted in good short-term outcomes in 4 feet in 3 adolescent patients.

Fresh osteochondral allograft transplantation for the knee: current concepts.

Fresh osteochondral allograft (OCA) transplantation has been used to manage a wide spectrum of chondral and osteochondral knee disorders. Basic science and clinical studies support the safety and efficacy of the procedure. Transplantation of viable, mature hyaline cartilage into the affected area is an advantage of the procedure, which can be used to restore bone stock in complex or salvage scenarios. Indications for OCA transplantation in the knee include primary management of large chondral or osteochondral defects and salvage of previously failed cartilage repair. The procedure also can be used for complex biologic knee reconstruction in the setting of osteonecrosis, fracture malunion, or posttraumatic arthritis. Challenges associated with OCA transplantation include allograft storage and size matching, tissue availability, chondrocyte viability, the possibility of immunologic graft response, and a demanding surgical technique. Future research should focus on optimizing allograft viability and healing and refining current surgical indications and techniques.

Normal curvature of glenoid surface can be restored when performing an inlay osteochondral allograft: an anatomic computed tomographic comparison.

PURPOSE: The purpose of this study was to quantitatively measure the morphology of the glenoid and to assess feasibility of using the medial tibial plateau surface as a donor for osteoarticular allograft reconstruction of the glenoid. METHODS: Using computed tomography (CT), 10 tibias and 10 scapular models from our database (5 males and 5 females in each group) were randomly selected. Commercial software (Mimics, Materialize, Inc., Plymouth, MI) was used to extract the bone contours from the CT images and to reconstruct the 3-dimensional (3D) geometry of the scapula and tibia. By utilizing the software Creo Elements/Pro 5.0 (Parametric Technology Corp., Needham, MA), mean length and width of both the glenoid and medial tibial plateau were calculated. Radius of curvature was then measured in each 3D CT model at three intermediate segment points that were established within the length line at 25, 50, and 75 percent from superior to inferior in the glenoid and from posterior to anterior in the medial tibial plateau. Statistical analysis was performed and determined to be significant for P < 0.05. RESULTS: The mean (± SD) radius of curvature values at the established 25, 50, and 75 percent segments of the glenoid were 47.4 ± 17.5 mm, 51.2 ± 12.4 mm, and 45.9 ± 17.0 mm, respectively. For the medial tibial plateau, the radius of curvature at 25, 50, and 75 percent were 43.5 ± 9.7 mm, 37.4 ± 14.3 mm and 52.3 ± 21.5 mm, respectively. Values of the glenoid length were 34.0 ± 2.9 mm, and width values were 24.4 ± 2.3 mm. For the medial tibial plateau, the length was 42.6 ± 2.7 mm, and the width was 23.3 ± 4.3 mm. There was no statistical difference in the radius of curvature and dimensional surface area between the glenoid and medial tibial plateau surfaces. CONCLUSION: The 3D CT-based anatomic study found that there is a statistically similar relationship in the radius of curvature of the glenoid and the medial tibial plateau surface. This concept may allow the medial tibial plateau to be used as a donor for osteoarticular allograft reconstruction of the glenoid, especially in young patients where previous studies have demonstrated that the success rate in shoulder replacements is not as good as in older patients.

Bipolar fresh osteochondral allograft for the treatment of glenohumeral post-traumatic arthritis.

PURPOSE: Surgical management of end-stage glenohumeral osteoarthritis represents a challenge in young patients. Bipolar fresh osteochondral allograft (BFOA) represents a fascinating option to prosthetic substitution. Aim of this report is to describe an original technique for BFOA implantation in the shoulder and to describe the clinical and histological results at 30-month follow-up. METHODS: A 47-year-old man received BFOA of the shoulder. Clinical and radiographical evaluations were carried out periodically up to 30 months. RESULTS: The clinical score increased from 40 to 78 points (Constant Score), decreased from 64 points to 10 (DASH Disability/Symptom Score) and from 94 points to 0 (DASH Work module Score). Radiographically arthritis and partial reabsorption of the implanted surfaces were evident. CONCLUSIONS: The clinical result obtained in this patient seems to support the applicability of BFOA in the shoulder with severe post-traumatic arthritis and with intact rotator cuff. Although unrelated to the clinical result, the occurrence of arthritis of the implanted surfaces is cause of concern. LEVEL OF EVIDENCE: Case report, Level V.

Osteochondral transplantation using autografts from the upper tibio-fibular joint for the treatment of knee cartilage lesions.

PURPOSE: Treatment of large cartilage lesions of the knee in weight-bearing areas is still a controversy and challenging topic. Autologous osteochondral mosaicplasty has proven to be a valid option for treatment but donor site morbidity with most frequently used autografts remains a source of concern. This study aims to assess clinical results and safety profile of autologous osteochondral graft from the upper tibio-fibular joint applied to reconstruct symptomatic osteochondral lesions of the knee. METHODS: Thirty-one patients (22 men and 9 women) with grade 4 cartilage lesions in the knee were operated by mosaicplasty technique using autologous osteochondral graft from the upper tibio-fibular joint, between 1998 and 2006. Clinical assessment included visual analog scale (VAS) for pain and Lysholm score. All patients were evaluated by MRI pre- and post-operatively regarding joint congruency as good, fair (inferior to 1 mm incongruence), and poor (incongruence higher than 1 mm registered in any frame). Donor zone status was evaluated according to specific protocol considering upper tibio-fibular joint instability, pain, neurological complications, lateral collateral ligament insufficiency, or ankle complaints. RESULTS: Mean age at surgery was 30.1 years (SD 12.2). In respect to lesion sites, 22 were located in weight-bearing area of medial femoral condyle, 7 in lateral femoral condyle, 1 in trochlea, and 1 in patella. Mean follow-up was 110.1 months (SD 23.2). Mean area of lesion was 3.3 cm2 (SD 1.7), and a variable number of cylinders were used, mean 2.5 (SD 1.3). Mean VAS score improved from 47.1 (SD 10.1) to 20.0 (SD 11.5); p = 0.00. Similarly, mean Lysholm score increased from 45.7 (SD 4.5) to 85.3 (SD 7.0); p = 0.00. The level of patient satisfaction was evaluated, and 28 patients declared to be satisfied/very satisfied and would do surgery again, while 3 declared as unsatisfied with the procedure and would not submit to surgery again. These three patients had lower clinical scores and kept complaints related to the original problem but unrelated to donor zone. MRI score significantly improved at 18-24 months comparing with pre-operative (p = 0.004). No radiographic or clinical complications related to donor zone with implication in activity were registered. CONCLUSIONS: This work corroborates that mosaicplasty technique using autologous osteochondral graft from the upper tibio-fibular joint is effective to treat osteochondral defects in the knee joint. No relevant complications related to donor zone were registered. LEVEL OF EVIDENCE: Case series, Level IV.

Weightbearing ovine osteochondral defects heal with inadequate subchondral bone plate restoration: implications regarding osteochondral autograft harvesting.

PURPOSE: It is unknown what causes donor site morbidity following the osteochondral autograft transfer procedure or how donor sites heal. Contact pressure and edge loading at donor sites may play a role in the healing process. It was hypothesized that an artificially created osteochondral defect in a weightbearing area of an ovine femoral condyle will cause osseous bridging of the defect from the upper edges, resulting in incomplete and irregular repair of the subchondral bone plate. METHODS: To simulate edge loading, large osteochondral defects were created in the most unfavourable weightbearing area of 24 ovine femoral condyles. After killing at 3 and 6 months, osteochondral defects were histologically and histomorphometrically evaluated with specific attention to subchondral bone healing and subchondral bone plate restoration. RESULTS: Osteochondral defect healing showed progressive osseous defect bridging by sclerotic circumferential bone apposition. Unfilled area decreased significantly from 3 to 6 months (P = 0.004), whereas bone content increased (n.s.). Complete but irregular subchondral bone plate restoration occurred in ten animals. In fourteen animals, an incomplete subchondral bone plate was found. Further common findings included cavitary lesion formation, degenerative cartilage changes and cartilage and subchondral bone collapse. CONCLUSIONS: Osteochondral defect healing starts with subchondral bone plate restoration. However, after 6 months, incomplete or irregular subchondral bone plate restoration and subsequent failure of osteochondral defect closure is common. Graft harvesting in the osteochondral autograft transfer procedure must be viewed critically, as similar changes are also present in humans. LEVEL OF EVIDENCE: Prognostic study, Level III.

Effectiveness and limitations of autologous osteochondral grafting for the treatment of articular cartilage defects in the knee.

PURPOSE: To evaluate the effectiveness and limitations of autologous osteochondral grafting for the treatment of articular cartilage defects in the knee. METHODS: The subjects were 40 patients who had undergone autologous osteochondral grafting. Fifteen knees had cartilage defects combined with anterior cruciate ligament tears (ACL group), 15 knees had cartilage defects combined with osteoarthritis (OA group), and 10 knees had cartilage defects combined with osteochondral dissecans (OCD group). From one to five osteochondral pegs were harvested from the less-weight-bearing periphery of the articular surface of the femoral condyle and grafted to cartilage defects. The clinical results were assessed based on the Lysholm score and radiographic and magnetic resonance imaging (MRI) image assessment. RESULTS: The median follow-up duration was 24 months (range from 12 to 41 months). The mean Lysholm score following treatment was improved in all groups. The patients who had cartilage defects combined with OA had a significantly poorer prognosis than did those with cartilage defects combined with ACL or OCD. In the OA group, advanced stage and an alignment abnormality were correlated with poor prognosis. Advanced age was correlated with poor prognosis. Other parameters showed no significant difference in prognosis. CONCLUSION: Autologous osteochondral grafting was found to be an effective technique for treating relatively young patients who had cartilage defects combined with ACL injury or OCD, but this technique showed limited results in treating cartilage defects based on advanced patient age and degenerative changes in the cartilage. LEVEL OF EVIDENCE: Diagnostic studies-investigating a diagnostic test, Level III.

New classification for correction of alar retraction using the alar spreader graft.

BACKGROUND: Identifying the cause of alar retraction is essential for proper correction of this deformity. In secondary surgery, aimed primarily at cephalic orientation and medialization of the lateral crus, corrections involving spreading and lateralization of the lateral crus can achieve a more horizontal orientation. In their clinic, the authors have practiced the use of an alar spreader graft to support the spread of the lateral crus. For the lateral crus to move freely without any resistance, it is critical to release the nasal hinge and pyriform ligament. A frontal view of the alar notching and the direction of the lateral crus are highly important factors needed to determine the cause of alar retraction. This report describes a new classification system for alar retractions viewed from the front to aid in determining the cause of the retraction and the surgical management. METHODS: From March 2008 to July 2010, 31 alar retractions were corrected using alar spreader grafts for patients showing clear alar retractions in frontal views. RESULTS: Satisfactory results without severe complications were obtained in 30 cases, with undercorrection in only 1 case. The alar cartilage was completely released to facilitate lateralization and caudal mobilization. An alar spreader graft then was used to support the lateral crus until a biologic scar cast was formed. CONCLUSION: The use of alar spreader grafts to correct alar retractions provided consistently good results. The attempt also was made to enhance the treatment strategy based on this classification system derived from frontal views of alar retraction. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266 .

Hypoplastic lateral crus causing alar retraction and underprojected nasal tip: correction with multiple grafts.

A case of severe alar retraction and underprojected nasal tip due to hypoplastic lateral crura was successfully treated using a columellar strut graft, lateral crus replacement graft, and lateral crus caudalization graft and Medpor implant. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266.

Superlarge living hyaline cartilage graft contributed by the scale-changed porous 3D culture system for joint defect repair.

It is known that an excellent hyaline cartilage phenotype, an internal microstructure with safe crosslinking and available size flexibility are the key factors of cartilage grafts that allow for clinical application. Living hyaline cartilage grafts (LhCGs) constructed by phase-transfer hydrogel (PTCC) systems were reported to have a hyaline phenotype and bionic microstructure. By employing chondrocytes to secrete matrix in the hydrogel and then removing the material to obtain material-free tissuein vitro, LhCG technology exhibited superior performance in cartilage repair. However, PTCC systems could only produce small-sized LhCGs because of medium delivery limitations, which hinders the clinical application of LhCGs. In this study, we prepared three different noncrosslinked gelatin microspheres with diameters from 200 µm to 500 µm, which replaced the original pore-forming agent. The new PTCC system with the mixed and gradient porous structure was used for the preparation of superlarge LhCGs with a continuous structure and hyaline phenotype. Compared to the original technique, the porous gradient structure promoted nutrient delivery and cartilage matrix secretion. The small size of the microporous structure promoted the rapid formation of matrix junctions. The experimental group with a mixed gradient increased cartilage matrix secretion significantly by more than 50% compared to the that of the control. The LhCG final area reached 7 cm2without obvious matrix stratification in the mixed gradient group. The design of the scale-changed porous PTCC system will make LhCGs more promising for clinical application.

A novel autologous-made matrix using hyaline cartilage chips and platelet-rich growth factors for the treatment of full-thickness cartilage or osteochondral defects: Preliminary results.

PURPOSE: To report the clinical, functional, and magnetic resonance imaging (MRI)-based outcomes of a novel autologous-made matrix consisting of hyaline cartilage chips combined with mixed plasma poor rich in platelets clot and plasma rich in growth factors (PRGF) for the treatment of knee full-thickness cartilage or osteochondral defects. METHODS: Between July 2015 and January 2018, all patients with full-thickness cartilage or osteochondral defects undergoing this novel cartilage restoration surgical technique were approached for eligibility. Indications for this procedure included traumatic or atraumatic full-thickness knee cartilage defects or osteochondritis dissecans. Patients were included if they had no concomitant use of stem cells, previous ipsilateral cartilage repair procedure, or follow-up was less than 10 months. The outcomes included data on current symptoms, physical exam, patient-reported, and functional outcomes (visual analogue scale (VAS) for pain, Lysholm score, Tegner activity scale, International Knee Documentation Committee (IKDC) subjective form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Lequesne index, and short form-12 (SF-12)) and the magnetic resonance observation of cartilage repair tissue (MOCART) score. These outcomes were compared to preoperative values, except for the MOCART score. RESULTS: Fifteen patients were included in this preliminary study: mean (standard deviation (SD), range) follow-up 15.9 months (7.2, 10-32), age 26.8 years (12.1, 16-58), and body mass index 23.2 (2.1, 19.3-26.9). There were 14 men (93%) and 1 woman (7%). There was a statistically significant improvement between pre- and postoperative periods for VAS for pain (p = 0.003), Lysholm score (p = 0.002), IKDC subjective form (p = 0.003), WOMAC for pain (p = 0.005), WOMAC for stiffness (p = 0.01), WOMAC for function (p = 0.002), Lequesne Index (p = 0.002), and SF-12 physical component summary (p = 0.007). The postoperative mean (SD; range) MOCART score was 70 (12.4; 40-85). CONCLUSIONS: The use of this novel cartilage restoration surgical technique provides excellent clinical, functional, and MRI-based outcomes in young, active individuals with full-thickness cartilage or osteochondral defects. LEVEL OF EVIDENCE: Level IV-Therapeutic case series.

Stabilized albumin coatings on engineered xenografts for attenuation of acute immune and inflammatory responses.

Xenogeneic grafts are promising candidates for transplantation therapy due to their easily accessible sources. Nevertheless, the immune and inflammatory responses induced by xenografts need to be addressed for clinical use. A novel and facile method was introduced for the attenuation of immune and inflammatory responses by extending the immune evasion potential of albumin to the tissue engineering field and coating albumin, which could passivate biomaterial surfaces, onto xenografts. Albumin was first modified by dopamine to enhance its adhesion on graft surfaces. Porcine chondrocytes derived living hyaline cartilage graft (LhCG) and decellularized LhCG (dLhCG) were applied as xenograft models implanted in the omentum of rats. Both LhCG which contained porcine chondrocytes as well as secreted ECM and dLhCG which was mainly composed of the porcine source ECM showed alleviated immune and inflammatory responses after being coated with albumin at cell, protein and gene levels, respectively. Significantly less inflammatory cells including neutrophils, macrophages and lymphocytes were recruited according to pathological analysis and immunohistochemistry staining with lower gene expression encoding inflammation-related cytokines including MCP-1, IL-6 and IL-1ß after employing LhCG and dLhCG with albumin passivation coating.

Full-Scale Osteochondral Regeneration by Sole Graft of Tissue-Engineered Hyaline Cartilage without Co-Engraftment of Subchondral Bone Substitute.

In this study, full-scale osteochondral defects are hypothesized, which penetrate the articular cartilage layer and invade into subchondral bones, and can be fixed by sole graft of tissue-engineered hyaline cartilage without co-engraftment of any subchondral bone substitute. It is hypothesized that given a finely regenerated articular cartilage shielding on top, the restoration of subchondral bones can be fulfilled via spontaneous self-remodeling in situ. Hence, the key challenge of osteochondral regeneration lies in restoration of the non-self-regenerative articular cartilage. Here, traumatic osteochondral lesions to be repaired in rabbit knee models are endeavored using novel tissue-engineered hyaline-like cartilage grafts that are produced by 3D cultured porcine chondrocytes in vitro. Comparative trials are conducted in animal models that are implanted with living hyaline cartilage grafts (LhCG) and decellularized LhCG (dLhCG). Sound osteochondral regeneration is gradually revealed from both LhCG and dLhCG-implanted samples 50-100 d after implantation. Quality regeneration in both zones of articular cartilage and subchondral bones are validated by the restored osteochondral composition, structure, phenotype, and mechanical property, which validate the hypothesis of this study.

Hyaline cartilage surface study with an environmental scanning electron microscope. An experimental study.

To obtain images of the articular surface of fresh osteochondral grafts using an environmental scanning electron microscope (ESEM). To evaluate and compare the main morphological aspects of the chondral surface of the fresh grafts. To develop a validated classification system on the basis of the images obtained via the ESEM. The study was based on osteochondral fragments from the internal condyle of the knee joint of New Zealand rabbits, corresponding to fresh chondral surface. One hundred images were obtained via the ESEM and these were classified by two observers according to a category system. The Kappa index and the corresponding confidence interval (CI) were calculated. Of the samples analysed, 62-72% had an even surface. Among the samples with an uneven surface 17-22% had a hillocky appearance and 12-16% a knobbly appearance. As regards splits, these were not observed in 92-95% of the surfaces; 4-7% showed superficial splits and only 1% deep splits. In 78-82% of cases no lacunae in the surface were observed, while 17-20% showed filled lacunae and only 1-2% presented empty lacunae. The study demonstrates that the ESEM is useful for obtaining and classifying images of osteochondral grafts.