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Chondral injuries of the femoral head and their possible progression to osteoarthritis is well known. Regarding focal lesions in young patients, microfracturing or autologous chondrocyte implantation (ACI) are the most frequent used techniques to address them. Although ACI provides the better tissue quality, it is a two-step procedure and needs a lot of resources. Mincing cartilage is an old technique that has become popular again over the last few years, with good short-term results in threatening cartilage lesion in the knee. It seems intriguing to transfer this technique to the hip because you can harvest good-quality cartilage from the cam lesion, and it is a one-step procedure using autologous thrombin and fibrin. This technical note describes the repair of a parafoveal chondral defect using minced cartilage via surgical dislocation of the hip., Technique Video Video 1 Minced cartilage implantation for a cystic defect on the femoral head. Twenty-seven-year-old patient with a parafoveal chondral lesion, patient history (00:06 min), imaging (00:22), intraoperative findings (00:59), preparing of the cartilage defect (01:10), mincing and harvesting of the cartilage with the GraftNet device (Arthrex, Munich, Germany) (01:30), getting a membrane-like structure of the minced cartilage (01:46), implantation of the minced cartilage into the defect (01:58), sealing of the construct with PRP and autologous thrombin (02:16), and postoperative imaging and care (02:28).

Tibial plateau chondral defects can be difficult to diagnose and treat. Although grafting of femoral and patella chondral defects has become relatively commonplace, the tibial plateau offers unique challenges for some of the grafting techniques used in these locations, mostly because of limitations with exposure even in an open approach. Arthroscopic surgery makes treatment of these lesions more feasible, as it affords better access and visualization of tibial defects. The purpose of this article is to describe the arthroscopic management of a lateral tibial plateau chondral defect via autologous chondrocyte bone grafting. The technique consists of harvest of autologous cartilage from the intercondylar notch and repair of the tibial plateau defect with a slurry of autologous chondrocytes and bone marrow aspirate concentrate. In addition, CO2 is used as a medium to distend the joint in a tight compartment to keep the chondral defect dry. This technique is technically simple and does not require an extensive open technique or an expensive osteochondral allograft. It also avoids the staged management required in other types of autologous chondrocyte implantation, which require cartilage biopsy to produce a final product for implantation., Technique Video Video 1 This video demonstrates our arthroscopic technique for treatment of a tibial plateau osteochondral lesion via minced autologous chondrocytes harvested from the intercondylar notch. CO2 is used to aid in joint distension as well as to dry the bed of the defect.

Objective Cartilage repair strategies have seen improvement in recent years, especially with the use of scaffolds that serve as a template for cartilage formation. However, current fixation strategies are inconsistent with regards to retention, may be technically challenging, or may damage adjacent tissues or the implant itself. Therefore, the goal of this study was to evaluate the retention and repair potential of cartilage scaffolds fixed with an easy-to-implement bioresorbable pin. Design Electrospun hyaluronic acid scaffolds were implanted into trochlear groove defects in 3 juvenile and 3 adult pigs to evaluate short-term retention (2 weeks; pin fixation vs. press-fit and fibrin fixation) and long-term repair (8 months; scaffold vs. microfracture), respectively. Results For the retention study, press-fit and fibrin fixation resulted in short-term scaffold dislodgment ( n = 2 each), whereas pin fixation retained all scaffolds that were implanted ( n = 6). Pin fixation did not cause any damage to the opposing patellar surface, and only minor changes in the subchondral bone were observed. For long-term repair, no differences were observed between microfracture and scaffold groups, in terms of second-look arthroscopy and indentation testing. On closer visualization with micro computed tomography and histology, a high degree of variability was observed between animals with regard to subchondral bone changes and cartilage repair quality, yet each Scaffold repair displayed similar properties to its matched microfracture control. Conclusions In this study, pin fixation did not cause adverse events in either the short- or the long-term relative to controls, indicating that pin fixation successfully retained scaffolds within defects without inhibiting repair.

Introduction Collagen scaffolds are a good surgical option for covering large focal osteochondral defects in the knee. In the recent literature there is a wide range of patient profiles and chondral defect treatments (chondral and osteochondral defects, associated procedures, etc.). The aim of the present study was to evaluate clinical and imaging outcomes with collagen scaffolds and to assess any correlation between medium-term clinical outcome and MRI features. The hypothesis was that there is no correlation between clinical outcome and MRI after 2 years postoperatively. Material and methods A single-center retrospective observational study included all patients receiving a MaioRegen® scaffold for large painful focal osteochondral defect of the femoral condyle. There were 17 patients, with a mean age of 28 ± 9 years. Defect locations comprised 12 medial femoral condyles, 4 lateral femoral condyles and 1 lateral tibial plateau. Mean defect area was 4.5 ± 1.4 cm2. All patients were evaluated clinically and on KOOS and objective and subjective IKDC scales, with MRI at last follow-up. Results At a mean follow-up of 46 ± 17 months, mean subjective IKDC was 67.8 ± 23; KOOS scores were: symptoms, 78 ± 22; pain, 78 ± 23; function, 85 ± 20; sports, 66 ± 27; and activities of daily living, 59 ± 25. MRI MOCART score revealed incomplete scaffold healing in 21.4% of cases, with variable signal intensity within regenerated tissue. Functional scores did not correlate with reconstruction aspect on MRI. Discussion/Conclusion 3D collagen scaffolds yield good medium-term clinical outcomes in large osteochondral defects of the knee. There is, however, a discrepancy between MRI features of the recipient site and objective and subjective clinical scores. These scaffolds may be a good option for treating large focal osteochondral defects in knees of young patients, but MRI does not provide satisfactory medium-term assessment.

Background Post-sprained ankles may sustain ligamentous tear, chondral defect, or osteochondral lesions (OCL). Being widely available and does not depend on high-end machine, the aim of this study was to assess the value of high resolution multi-detector CT arthrography (CTA) in detection of various ligamentous tears, chondral defects, and osteochondral lesions in case of sprain-related persistent ankle pain. Results There were 34 (68%) cases of ligamentous injury, most of which had single ligament affection whereas some cases demonstrated multi-ligamentous injury, and the total number of individual injured ligaments was 42 ligaments. There were 36 cases (72%) which had either chondral or osteochondral defects; the total number of OCL was 21 lesions and the total number of segmental cartilage defects was 20. Conclusion This study emphasized the diagnostic importance of multi-detector CTA in sprain-related ankle pain. In persistent post-sprained ankle pain, multi-detector CTA is a helpful imaging modality which could be utilized for detection of OCL, chondral defects, and various ligamentous tears.

Objective Hyaluronic acid–transglutaminase (HA-TG) is an enzymatically crosslinkable adhesive hydrogel with chondrogenic properties demonstrated in vitro and in an ectopic mouse model. In this study, we investigated the feasibility of using HA-TG in a collagen scaffold to treat chondral lesions in an ovine model, to evaluate cartilage regeneration in a mechanically and biologically challenging joint environment, and the influence of the surgical procedure on the repair process. Design Chondral defects of 6-mm diameter were created in the stifle joint of skeletally mature sheep. In a 3-month study, 6 defects were treated with HA-TG in a collagen scaffold to test the stability and biocompatibility of the defect filling. In a 6-month study, 6 sheep had 12 defects treated with HA-TG and collagen and 2 sheep had 4 untreated defects. Histologically observed quality of repair tissue and adjacent cartilage was semiquantitatively assessed. Results HA-TG adhered to the native tissue and did not cause any detectable negative reaction in the surrounding tissue. HA-TG in a collagen scaffold supported infiltration and chondrogenic differentiation of mesenchymal cells, which migrated from the subchondral bone through the calcified cartilage layer. Additionally, HA-TG and collagen treatment led to better adjacent cartilage preservation compared with empty defects (P < 0.05). Conclusions This study demonstrates that the adhesive HA-TG hydrogel in a collagen scaffold shows good biocompatibility, supports in situ cartilage regeneration and preserves the surrounding cartilage. This proof-of-concept study shows the potential of this approach, which should be further considered in the treatment of cartilage lesions using a single-step procedure., Cartilage, 13 (2), ISSN:1947-6035

One-step clinical therapies of articular cartilage defects remains a challenge. In this study, a strategy was proposed to utilize type II collagen (Col-II) gels with autologous bone marrow-derived cells (BMDCs) embedded to repair full-thickness chondral defects. Its feasibility and efficacy were further assessed in a minipig model. An 8-mm full-thickness chondral defect was created on the femoral trochlea of two knees in Guizhou minipigs. One knee received Col-II gels with BMDCs implantation versus the untreated one as control. After 1, 3, and 6 months operation, the animals were sacrificed, and the repair outcomes of chondral defects were evaluated using Magnetic Resonance Imaging (MRI), macro- and microscopic observation, and histological analysis. The treatment group showed significantly better repair outcomes of chondral defects than that in the control group at each time point (P < 0.01). Furthermore, the image showed that the repaired tissue in the treatment group was more similar to the surrounding healthy cartilage tissue. Based on the hyaline-like tissue regenerated ability, this one-step strategy provides a promising therapeutic potential for clinical application.

The introduction of mesenchymal stem cells (MSCs) into orthopedics has opened a variety of new evolving cellular treatments for treatment of chondral injuries. These cells are processed in one-step protocols or by cellular expansion to regenerate cartilage tissue and often combined with existing therapies such as microfracture. MSCs vary in their differentiation capacities, depending on their source, and cell harvest at each source yields varying numbers of cells. Recent literature has indicated MSCs to be safe and show positive results in producing superior cartilage tissue quality as well as better clinical patient outcomes. However, the main issue with MSC treatments is lack of standardization and quality control which has been a recent focus in stem cell medicine. Overall, the evidence in favor of MSC therapies is not definitive, and future research holds the key to determining their role in treatment. This chapter outlines the current characteristics MSCs have in repairing symptomatic cartilage defects.

The treatment of chondral defects using microdrilling often results in a mechanically weak fibrocartilagenous repair, rather than a more robust hyaline cartilage repair. Many different microfracture/microdrilling augmentation techniques have been described, including the use of cellular products to enhance healing. Autologous peripheral blood progenitor cells can be obtained via apheresis after administration of granulocyte colony stimulating factor (G-CSF) and have been used successfully augment microdrilling in clinical patients. The objective of this study was to use apheresis derived mononuclear blood cells to augment microdrilling treatment of a cartilage defect in an ovine model in order to determine the effect on healing. Forty adult female sheep were used in this study and were divided into a control group (microdrilling alone) and a treatment group (microdrilling, hyaluronic acid and apheretic product). Outcome measurements included weight bearing on the operated limb, macroscopic scoring of the joint, histology and immunohistochemistry. In addition, MRI was used to attempt to identify SPION labelled cells from the apheretic product in the operated limbs. The results showed a significant increase in healing as measured by the modified O'Driscoll sore in the treated group. No evidence of homing of SPION labelled cells to the defect was found and no correlation was found between the response to G-CSF administration or concentration of CD34+ve and outcome. A correlation was found between healing and the concentration of white blood cells and peripheral blood mononuclear cell numbers in the apheretic product. This article is protected by copyright. All rights reserved.

Chondral defects of the knee are prevalent and often encountered during arthroscopic procedures. Despite the limited healing potential of chondral defects, several treatment options have been proposed. However, microfracture, osteochondral autograft (or allograft) transfer, autologous chondrocyte implantation, and matrix-induced autologous chondrocyte implantation are all associated with their respective shortcomings. As such, the optimal treatment for chondral defects of the knee remains unclear. Recently, many authors have advocated treating chondral defects with biological therapies and scaffold-based treatments. Bone marrow aspirate concentrate, a cell-based injection, has gained particular attention because of its differentiation capacity and potential role in tissue regeneration. In addition, scaffold cartilage treatments have emerged and reached clinical practice. BioCartilage is one form of scaffold, which consists of extracellular matrix, and has been claimed to promote the regeneration of hyaline-like cartilage. This article presents our technique of arthroscopic chondral defect repair using BMAC and BioCartilage.

Background: BST-CarGel (CarGel) is an injectable chitosan scaffold that is mixed with fresh, autologous blood and injected into the site of microfracture (MF) to physically stabilize clots and enhance cartilage repair. Purpose: To evaluate short-term clinicoradiological outcomes of patients treated arthroscopically for acetabular chondral defects with CarGel in conjunction with MF compared with those treated with MF alone. Study Design: Cohort study; Level of evidence, 3. Methods: All patients who underwent hip arthroscopy and received MF with or without CarGel for acetabular chondral defects between 2014 and 2018 with a minimum 2-year clinicoradiological follow-up were included. Intraoperative details, postoperative complications, and clinical outcome scores, including the international Hip Outcome Tool–33 (iHOT-33), Hip Outcome Score (HOS)–Activities of Daily Living (HOS-ADL), and Hip Outcome Score–Sports Profile, were analyzed. Serial plain radiographs were assessed independently by 2 blinded observers. A survival analysis was performed to identify the number of cases converted to total hip arthroplasty (THA) in both groups, which was correlated with the cartilage defect size at the time of surgery. Results: Eighty patients (54 CarGel and 26 MF) were evaluated, including 56 men (70%) and 48 right hips (60%). Three patients were lost to follow-up. There were no major adverse events in either group. The average defect size was 3.63 and 4.97 cm2 in MF and CarGel, respectively ( P = .002). There was a statistically significant improvement in iHOT-33 (from 43.24 to 60.17 in MF and from 41.13 to 58.39 in CarGel) and HOS-ADL (from 62.25 to 76.75 in MF and from 44.69 to 79.16 in CarGel) scores. There was no difference between the 2 groups in the outcome scores after adjusting for covariates. Survival analysis showed 34.6% of MF cases and 5.9% of CarGel cases were converted to THA ( P = .001). The mean defect size of the failure group was higher in CarGel than in MF (8.83 and 3.72 cm2, respectively). Mean joint space reduction was 1.41 mm in MF and 0.19 mm in CarGel ( P < .001). Conclusion: Two-year clinicoradiological results were promising in these lesions that are difficult to treat. Arthroscopic treatment of chondral acetabular defects with CarGel demonstrated a significant decrease in progressive loss of joint space and conversion to THA compared with MF as an isolated procedure.

Over the past decade, arthroscopic microfracture has become increasingly popular to treat full-thickness (Outerbridge grade IV) chondral defects of the hip. This procedure borrows marrow stimulation treatment principles and techniques from knee arthroscopy, with similar mixed clinical outcomes that may be more favorable in the short term (

Objective To determine biomechanical effects of knee cartilage defect perimeter morphology based on cartilage strain and opposing subchondral bone contact. Design Articular cartilage defects were created in 5 bovine femoral condyles: group 1, 45° inner bevel with 8-mm rim; group 2, vertical with 8-mm rim; and group 3, 45° outer bevel with 8-mm base. Samples were placed into a custom-machined micro–computed tomography tube and subjected to 800 N of axial loading. DICOM data were used to calculate cartilage thickness 4 and 6 mm from the center, distance between tibial cartilage surface and femoral subchondral bone, and contact width between tibial cartilage and subchondral bone. Strain 4 mm from the center and both absolute and change in distance (mm) to subchondral bone were compared between groups 1 and 2 using paired t tests. Strain at 6 mm and distance changed, loaded distance, and contact width (mm) were compared between groups using the Friedman test with post hoc analysis using Wilcoxon signed rank test. Results No significant differences in rim strain were noted between groups 1 and 2 at 4 mm ( P = 0.10) and between groups 1, 2, and 3 at 6 mm ( P = 0.247) from the defect center. The loaded distance was significantly different between groups 1 and 3 ( P = 0.013). No significant change in distance to the subchondral bone was found between groups ( P = 0.156). The difference in subchondral bone contact area approached but did not reach significance ( P = 0.074). Conclusion When debriding focal articular cartilage defects, establishment of an inner bevel decreases tissue deformation and contact with opposing subchondral bone.

Cartilage disorders, including focal cartilage lesions, are among the most common clinical problems in orthopedic practice. Left untreated, large focal lesions may result in progression to osteoarthritis, with tremendous impact on the quality of life of affected individuals. Current management strategies have shown only a modest degree of success, while several upcoming interventions signify better outcomes in the future. Among these, stem cell therapies have been suggested as a promising new era for cartilage disorders. Certain characteristics of the stem cells, such as their potential to differentiate but also to support healing made them a fruitful candidate for lesions in cartilage, a tissue with poor healing capacity. The aim of this editorial is to provide an update on the recent advancements in the field of stem cell therapy for the management of focal cartilage defects. Our goal is to present recent basic science advances and to present the potential of the use of stem cells in novel clinical interventions towards enhancement of the treatment armamentarium for cartilage lesions. Furthermore, we highlight some thoughts for the future of cartilage regeneration and repair and to explore future perspectives for the next steps in the field.

Background: It is unclear whether chondral fragments without bone have the potential to heal after fixation. Controversy exists and opinions differ regarding the optimal treatment of chondral defects after pure chondral fracture. Purpose: To determine clinical and radiographic outcomes after internal fixation of traumatic chondral fragments repaired to bone in the knee. Study Design: Case series; Level of evidence, 4. Methods: A retrospective clinical and radiographic evaluation of 10 male patients with a mean age of 14.6 years (range, 10-25 years) at the time of surgery was performed. Eight of 10 patients were skeletally immature. Patients were selected by operating surgeons per the presence of a large displaced pure chondral fragment on magnetic resonance imaging and confirmed on intraoperative inspection. All patients had a diagnosed traumatic displaced pure chondral fracture of the knee (without bone) and underwent internal fixation with minimum 1-year follow-up. Validated patient-reported and surgeon-measured outcomes were collected pre- and postoperatively. All patients were evaluated at a mean 56 months postoperatively. Results: At surgery, the mean defect size that was primarily repaired with the displaced chondral fragment was 1.9 × 2.0 cm. With minimum 1-year follow-up, there were no clinical failures. All 8 patients who had subsequent magnetic resonance imaging follow-up had radiographic evidence of complete healing of the chondral fragment back to bone. At a mean follow-up of 56 months (range, 13-171 months; median, 36 months), patients had a mean International Knee Documentation Committee score of 94.74 (range, 87.4-100), a mean Marx Activity Scale score of 14.4 (range, 8-16), and a mean Tegner Activity Scale score of 7 (range, 5-9). At final follow-up, all patients except 1 returned to sports. Conclusion: The treatment of large traumatic chondral fragments is controversial. In this select series of 10 young patients who underwent primary repair with internal fixation, there were no failures clinically. Patients demonstrated excellent short-term clinical and radiographic results after fixation of these relatively large chondral fragments in the knee.

Articular cartilage is critical for painless and low-friction range of motion; however, disruption of articular cartilage, particularly in the knee joint, is common. Treatment options are based on the size and depth of the chondral defect, as well as involvement of subchondral bone. The gold standard for evaluation of articular cartilage is with arthroscopy, but it is limited by its ability to objectively judge the depth and severity of chondral damage. Optical reflection spectroscopy has been introduced to objectively assess the thickness of cartilage. We present a technique to systematically evaluate the articular cartilage of the knee using BioOptico optical reflection spectroscopy (Arthrex) to better evaluate those with visible chondral and subchondral defects.

Tibiofemoral cartilage defects are often found in concurrence with and may be secondary to malalignment. This case discusses the treatment and evaluation of a 34-year-old female with a history of 2 years of atraumatic medial knee pain with prior partial meniscectomy found to have varus malalignment of 6° and a 2 cm2 chondral defect in the medial femoral condyle with an intact subchondral bone plate. When determining the appropriate treatment for a patient with these or similar symptoms, factors to consider include the following: degree of malalignment, smoking status, BMI, contralateral defects, concomitant meniscal lesions, extent of arthritis, range of motion, and likelihood of postoperative compliance. This discussion uses a review of recent literature to address the process of choosing an appropriate treatment and determining whether or not to correct cartilage abnormalities in conjunction with misalignment correction.

Life 11(3), 244 (2021). doi:10.3390/life11030244 special issue: "Special issue "Focal chondral defects" / special issue editors: Filippo Migliorini, guest editor; Nicola Maffulli, guest editor", Published by MDPI, Basel

Tibial tubercle osteotomy (TTO) is a procedure that may be used to address a wide array of patellofemoral joint pathology. The most common indications for TTO include (1) patellar instability, including either a lateralized force vector or abnormal patellar alta, and (2) patellar focal cartilage defects or chondromalacia. Customization of the TTO can effectively address the patellofemoral joint pathology by modifying patellar tracking in the trochlear groove and/or altering the contact pressures experienced by the patellofemoral cartilage. TTO may be most successful when performed in conjunction with soft-tissue stabilization and/or biological augmentation of chondral injuries. Specifically, isolated anteromedialization is recommended for focal, distal lateral patellar lesions; combined anteromedialization and cartilage restoration are recommended for medial, central, and/or panpatellar cartilage pathology; medialization with soft-tissue stabilization is recommended for a lateralized tubercle position (elevated tibial tubercle-trochlear groove distance); and distalization with soft-tissue stabilization is recommended for patella alta. Clinical studies have shown good to excellent results at long-term follow-up when a TTO is performed for patellar instability, whereas TTO performed for chondral defects has shown good to excellent outcomes that correlate strongly with the size and location of the chondral defect. With appropriate patient selection, TTO is a valuable tool for the treatment of patellofemoral joint pathology.

Chondral defects of the knee are frequently encountered during arthroscopy. For symptomatic lesions, several surgical options exist. Determining the best surgical option for a patient can be challenging for the treating surgeon. Autologous chondrocyte implantation (ACI) is an articular cartilage–restoring procedure that is commonly used to treat medium-to-large full-thickness cartilage lesions of the knee. It is a 2-stage procedure requiring cartilage biopsy, 4-6 weeks of in vitro chondrocyte expansion, followed by reimplantation. Short- and long-term outcome studies have been promising regarding patient satisfaction and durability. Realignment procedures, as indicated, have been shown to improve clinical outcome and longevity of the transplanted grafts. As newer generation techniques evolve, complications have been minimized.

Damage to articular cartilage can over time cause degeneration to the tissue surrounding the injury. To address this problem, scaffolds that prevent degeneration and promote neotissue growth are needed. We introduce a new hybrid scaffold that combines a stereolithography-based three-dimensional printed support structure with an injectable and photopolymerizable hydrogel for delivering cells to treat focal chondral defects. In this proof of concept study, we demonstrate the ability to a) infill the support structure with an injectable hydrogel precursor solution, b) incorporate cartilage cells during infilling using a degradable hydrogel that promotes neotissue deposition, and c) minimize damage to the surrounding cartilage when the hybrid scaffold is placed in situ in a focal chondral defect in an osteochondral plug that is cultured under mechanical loading. With the ability to independently control the properties of the structure and the injectable hydrogel, this hybrid scaffold approach holds promise for treating chondral defects.

Isolated, full-thickness articular cartilage lesions of the glenohumeral joint can cause pain, mechanical symptoms, and impaired function. Reports on operative management of these injuries with arthroscopic techniques, such as marrow stimulation, have shown improvement in patient symptoms. In cases where the subchondral bone is involved, osteochondral allograft (OCA) transplantation has shown positive results for contained, focal cartilage defects. The technique for OCA transplantation to treat Hill-Sachs lesions has been reported in detail, and there are multiple case series reporting on the outcomes of OCA used for this purpose. This Technical Note shows the application of OCA to treat a case of anchor arthropathy where a glenoid anchor placed during arthroscopic stabilization causes iatrogenic damage to the humeral head. This type of injury can result in cartilage lesions in uncommon locations, such as on the posterior humeral head. In this description, the technical pearls and pitfalls of managing difficult-to-access posterior humeral head lesions are presented along with the senior authors' general technique for OCA to treat focal lesions of the humeral head cartilage.

The use of three-dimensional (3D) printing has seen a vast expansion over recent years, with an increased application for its use in orthopaedics. This report details the use of 3D printing technology to aid in the treatment of a medial femoral condyle osteochondral defect in a 26-year-old female who had previously undergone a failed autograft procedure. A preoperative computed tomography scan of the knee and chondral defect was used to generate a 3D printed, one-to-one scale replica of the distal femur. This replica was then used to size a patient-specific allograft plug for the osteochondral transplantation procedure. The patient recovered well, and 1 year postoperatively the allograft was well incorporated into the medial femoral condyle and healed. This report illustrates the advantages of using a 3D printed model to allow for tactile feedback and improved visualization that will allow for improved understanding of complex surgical procedures. Level of evidence V.

The management of chondral defects is a challenging topic of current interest for scientists and surgeons. Chondral defects caused by tumor, trauma, infection, congenital malformations are very common in clinical, which seriously affect the patient’s function and quality of life. Even several centuries after its first observation, this problem has still not found a satisfactory and definitive answer. Cartilage tissue engineering, which involves novel natural scaffolds, has emerged as a promising strategy for cartilage regeneration and repair. In this chapter, we aimed to review the application of the scaffold materials in cartilage tissue engineering, including the conditions needed to meet the ideal stent, the preparation of scaffold materials, preparation methods and so on.

Focal chondral lesions of the glenohumeral joint, though less common than chondral defects in the knee or ankle, can be a significant source of pain in an active population. For patients in whom nonsurgical management fails, promising results have been reported after arthroscopic microfracture surgery to treat such lesions. However, microfracture leads to growth of fibrocartilage tissue and is biomechanically less durable than native hyaline cartilage. Recently, augmentation of the microfractured defect with micronized allogeneic cartilage and platelet-rich plasma has been described to restore hyaline-like cartilage and potentially protect the subchondral bone from postsurgical fracture biology within the base of the defect. We present a simple arthroscopic technique of implanting dehydrated, micronized allogeneic cartilage scaffold to treat an isolated chondral lesion of the glenoid.

Clinical trials of various procedures, including bone marrow stimulation, mosaicplasty, and autologous chondrocyte implantation, have been explored to treat articular cartilage defects. However, all of them have some demerits. We focused on autologous culture-expanded bone marrow mesenchymal stem cells (BMSC), which can proliferate without losing their capacity for differentiation. First, we transplanted BMSC into the defective articular cartilage of rabbit and succeeded in regenerating osteochondral tissue. We then applied this transplantation in humans. Our previous reports showed that treatment with BMSC relieves the clinical symptoms of chondral defects in the knee and elbow joint. We investigated the efficacy of BMSC for osteoarthritic knee treated with high tibial osteotomy, by comparing 12 BMSC-transplanted patients with 12 cell-free patients. At 16-month follow-up, although the difference in clinical improvement between both groups was not significant, the arthroscopic and histological grading score was better in the cell-transplanted group. At the over 10-year follow-up, Hospital for Special Surgery knee scores improved to 76 and 73 in the BMSC-transplanted and cell-free groups, respectively, which were better than preoperative scores. Additionally, neither tumors nor infections were observed in all patients, and in the clinical study, we have never observed hypertrophy of repaired tissue, thereby guaranteeing the clinical safety of this therapy. Although we have never observed calcification above the tidemark in rabbit model and human histologically, the repair cartilage was not completely hyaline cartilage. To elucidate the optimum conditions for cell therapy, other stem cells, culture conditions, growth factors, and gene transfection methods should be explored.

Recently, many clinical studies have been published regarding platelet-rich plasma (PRP) injection for early degenerative joint disease. We evaluated the cartilage repair potential of platelet-rich plasma when injected into the knee joint. Articular, cartilage defects 4 mm in diameter and circular in shape were made in the trochlear region of 20 knees in 10 New Zealand white rabbits who were divided into two groups. The left knees in the control group underwent microfracture, and the right knees in the experimental group underwent microfracture with subsequent injection of platelet-rich plasma. At week 12 following the surgery, the cartilage was observed macroscopically and histologically compared in the two groups. The control group showed incomplete and irregular fibrous tissue formation in the defect. The experimental group showed nearly complete defect coverage with neo-cartilage. In the histologic scoring, comparison of the control group and the experimental group differed significantly (p < 0.05).Therefore, injection of platelet-rich plasma used to treat articular cartilage defects of the knee appears to have some effect for cartilage regeneration.

Previous studies report professional athletes return to play following arthroscopic microfracture of the hip for chondral defects. Our hypothesis is that professional hockey players undergoing arthroscopic microfracture for chondral defects of the hip achieve the same performance they had pre-injury and compared to matched controls. Seventeen professional hockey players underwent arthroscopic microfracture for an Outerbridge grade IV chondral lesion. Concomitant procedures for labral pathology or FAI were included. Performance data for the full season preceding and following index procedure were analysed, in addition to two matched control players per subject. Data were collected at two points, 2 years apart. Eighty-two per cent (14/17) of players who underwent arthroscopic microfracture returned to play. The year prior to injury for the 14 players who returned was compared to the average of their individual controls. There was no statistical difference between the groups for age, number of seasons in the league, games played, time on ice, points, save percentage, and shots against goal. Post-operatively, there was no statistical difference between the treatment and control groups regarding performance measures. There was a trend towards a decrease in games played and points post-operatively compared with controls. The treatment group decreased 11 games played, while the controls decreased five games. The treatment group also decreased 14 points, while the controls decreased three points for the season. Professional hockey players with a discrete, full-thickness chondral defect of the hip are able to return to elite performance level following an arthroscopic microfracture procedure when compared to pre-injury outcomes and controls. III.