Treatment Of Chondral Defects Research Articles

A review of current concepts in radiofrequency chondroplasty

Radiofrequency (RF) chondroplasty is a promising treatment of chondral defects. The purpose of this study is to summarize current literature reporting the use of radiofrequency energy as an alternative treatment to mechanical shaving in chondroplasty. This review depicts the basic understanding of RF energy in ablating cartilage while exploring the basic science, laboratory evidence and clinical effectiveness of this form of chondroplasty. Laboratory studies have indicated that RF energy decreases inflammatory markers in the cartilage as well as providing optimal results with smoothing of chondral clefts. There have been concerns of chondrolysis due to heat damage of chondrocytes; however, this is unsubstantiated in clinical studies. These clinical trials have highlighted that RF energy is a safe and efficacious method of chondroplasty when compared to the mechanical shaving technique.

The effect of lesion size on clinical outcomes after microfracture: a 2 to 8 year follow-up study

Purpose: Microfracture is often the first choice treatment for chondral defects in the knee, but some studies have suggested outcomes are influenced by lesion size at the time of the index surgery. Some authors have suggested that microfracture is suitable only for lesions up to 200 mm2, and other authors have placed an upper size limit of 400 mm2 for microfracture. The purpose of this study was to determine if there was a relationship between the size of the cartilage lesion treated with the appropriate microfracture surgical technique and rehabilitation protocols and patient-centered outcomes. We hypothesized that at a minimum of two years after microfracture patient-reported function, activity level, and satisfaction with outcomes would be similar regardless of the chondral lesion size at the time of index surgery. Methods: An ethics board-approved clinical data registry was queried for knees with contained focal chondral lesions and treated with microfracture by a single surgeon. Six hundred ninety-two (692) knees met the inclusion criteria. The lesions were on the femoral condyles, the tibial plateaus, or in the patellofemoral joint. The size of the chondral lesion was carefully measured and documented at the index surgery. Patients were assigned to one of four groups based on lesion size: Group I <100 mm2, Group II 100-300 mm2, Group III 301-400 mm2, and Group IV >400mm2. Previously published microfracture technique and rehabilitation protocols were used. Average follow-up was four (4) years with a range of 2 to 8 years. The patient-centered outcomes measures used for this study were the Lysholm function score, the Tegner activity level scale, and patient satisfaction with outcomes where 0 = totally dissatisfied and 10 = totally satisfied. Results: At the latest follow-up, data were available as follows: Group I contained 123 patients, Group II had 138, Group III included 161, and Group IV contained 138 patients. Preoperatively, Groups I-III had an average Lysholm score of 62, and Group IV had an average Lysholm score of 50. At an average 4 years after the index microfracture procedure (range, 2 to 8 years) with 80% (560 of 692) follow-up, there were no significant differences between groups for Lysholm, Tegner, or patient satisfaction values (Table I). These findings were the same regardless of lesion location (femur, tibia, or patellofemoral joint). Conclusions: In this large group of patients with an average 4-year follow-up, lesion size at the time of index microfracture had no effect on the patient-reported function (Lysholm), activity level (Tegner) or patient satisfaction with outcomes. These results were consistent regardless of lesion location. These findings confirm our hypothesis that patient-centered outcomes are the same for a contained chondral lesion of the knee regardless of lesion size. With the proper surgical technique and rehabilitation protocols, size of the lesion should not be a limitation for the use of microfracture.Tabled 1Outcomes by Defect SizeLesion Size (mm2)Group I <100Group II 100 to 300Group III 301 to 400Group IV >400N123138161138Lysholm86.987.186.587.5Tegner4.64.84.85.0Patietn Satisfaction7.98.18.08.2 Open table in a new tab

Mesenchymal stem cell enhances chondral defects healing in horses

The purpose of this study was to evaluate the effect of intralesional Mesenchymal Stem Cells (MSC) on the treatment of experimentally induced articular chondral defects in horses, emphasizing the benefits of this application in veterinary medicine. Chondral defects were induced in the medial femoral trochlea of both hind limbs of four horses. Thirty days post induction; the horses were divided into two groups. The G1 was submitted to treatment with MSC and the G2 was the control group. Clinical evaluations, synovial fluid analysis and synovial Prostaglandin E2 (PGE2) assessment were performed prior to defects and fortnightly up to 120 and 150 days. Macroscopic, histopathological and histochemical evaluations were performed at the end of the experiment. The treatment with MSC reduced the intraarticular inflammatory process. The G1 showed lower PGE2 concentrations in the synovial fluid and greater percentage of mononuclear cells and lower percentages of lymphocytes and neutrophils. The treatment improved the macro and microscopic aspects of repair tissue. No difference was observed in the scores of lameness between the G1 and G2. The use of MSC in the treatment of chondral defects minimized joint inflammation, as confirmed by synovial fluid analysis. The treatment resulted in an improved repair tissue, verified by macroscopic examination, histochemical and histopathological analysis.

Matrix-associated stem cell transplantation (MAST) in chondral defects of foot and ankle is effective

The aim of the study was to assess the feasibility and clinical results of matrix-associated stem cell transplantation (MAST) and 2-year-follow-up in chondral defects of foot and ankle. In a prospective, consecutive, non-controlled clinical follow-up study, all patients with chondral defects, that were treated with MAST from April 1st to November 30th, 2009 were analyzed. The size and location of the chondral defects, method-associated problems and the Visual Analogue Scale Foot and Ankle (VAS FA) before treatment and at follow-up were registered and analyzed. Twenty-six chondral defects in 25 patients were included in the study. The mean age of the patients was 33 years (range, 16-48 years), 18 (72%) were male. The VAS FA before surgery was 49.2 on average (range, 24.3-68.4). The defects were located as follows: medial talar shoulder, n=9; lateral talar shoulder, n=13 (medial and lateral talar shoulder, n=1); distal tibia, n=1; posterior calcaneal facet, n=1; head of 1st metatarsal, n=2. The defect size was 1.1cm(2) on average (range, .5-6 cm(2)). All patients completed 2-year-followup. No complications or consecutive surgeries were registered. The mean VAS FA at follow-up was 94.5 (range, 73.4-100; t-test, p<.01). MAST led to good clinical scores. No complications were registered. Even though a control group is missing, we conclude that MAST is a safe and effective method for the treatment of chondral defects. The main advantage of MAST in comparison with ACI and MACI is the single procedure methodology. The advantage in comparison with AMIC is the potential higher concentration of stem cells.

Factors Influencing the Outcome of Autologous Chondrocyte Implantation: A Systematic Review

Autologous chondrocyte implantation (ACI) is an effective method of treatment of chondral defects of the knee. ACI outcomes are influenced by patient-, knee-, and lesion-specific factors. We compiled subject-level data from current studies on ACI and quantitatively analyzed this data set for associations between patient-, knee-, and lesion-specific factors and the outcome of ACI surgery. A systematic review of studies investigating ACI treatment outcomes in the knee was performed. Only studies that published subject-level data were included. Data on patient and lesion characteristics, as well as clinical outcome scores, were collected. Thirteen studies (305 defects) were included in this review. These studies showed that ACI treatment improves clinical outcomes in different patient populations. However, subject-specific variables such as patient age, gender, body mass index, duration of preoperative symptoms, as well as defect size and location were not associated with International Knee Documentation Committee score or visual analog scale score changes (p > 0.05 for all). Covariate analysis showed that patient age was related to symptom duration prior to surgery (p = 0.009). ACI surgery has been shown to improve outcomes in patients with chondral lesions of the knee. Despite evidence in the literature showing that multiple patient-, knee-, and lesion-specific factors may influence treatment outcomes, our review shows that these factors, solely, do not affect outcomes. However, together, they may synergistically affect outcomes.

The effect of hyaluronan combined with microfracture on the treatment of chondral defects: an experimental study in a rabbit model

Because articular hyaline cartilage has low potential for regeneration, numerous methods and techniques have been proposed to induce the reparation process. Microfracture is a convenient procedure for this purpose. However, the quality of the new cartilage after microfracture is still not as proper as original. In this experimental study, we used microfracture in combination with intraarticular application of hyaluronan in rabbit knee articular defect. Bilateral knee arthrotomies, chondral defects, and microfracture were created on each intercondylar notch in thirty rabbits. Rabbits received intraarticular injections of hyaluronan once a week for 3 weeks in the right knee, started from 1 week after injury. The left knees, which served as controls, were injected with normal saline. Biopsy was taken from both knees at the 4th and 6th weeks. In comparison with the control group, after 6 weeks we observed a higher potential for healing in the experimental group, with thicker and more organized repair tissue filling the defect. The current study reveals that application of hyaluronan after the microfracture might be beneficial in inducing articular cartilage defect reparation.

Operative treatment of chondral defects in the hip joint: a systematic review

Young patients with cartilage defects in the hip present a complex problem for the treating physician with limited treatment modalities available. Cartilage repair/replacement techniques have shown promising results in other joints, however, the literature regarding the hip joint is limited. The purpose of the current study is to conduct a systematic review of clinical outcomes following various treatments for chondral lesions of the hip and define the techniques for the treatment of these cartilage defects. The full manuscripts of 15 studies were reviewed for this systematic review including case studies, case series, and clinical studies. A variety of techniques have been reported for the treatment of symptomatic chondral lesions in the hip. Microfracture, cartilage repair, autologous chondrocyte implantation, mosaicplasty, and osteochondral allografting have all been used in very limited case series. Although good results have been reported, most studies lack both a control group and a large number of patients. However, the reported results in this article do provide a good foundation for treatments and stimulant for further study in an inherently difficult to treat young patient population with articular cartilage defects in the hip.

Operative Treatment of Chondral Defects in the Glenohumeral Joint

The objectives of this study were to conduct a systematic review of clinical outcomes after cartilage restorative and reparative procedures in the glenohumeral joint, to identify prognostic factors that predict clinical outcomes, to provide treatment recommendations based on the best available evidence, and to highlight literature gaps that require future research. We searched Medline (1948 to week 1 of February 2012) and Embase (1980 to week 5 of 2012) for studies evaluating the results of arthroscopic debridement, microfracture, osteochondral autograft or allograft transplants, and autologous chondrocyte implantation for glenohumeral chondral lesions. Other inclusion criteria included minimum 8 months' follow-up. The Oxford Level of Evidence Guidelines and Grading of Recommendations Assessment, Development and Evaluation (GRADE) recommendations were used to rate the quality of evidence and to make treatment recommendations. Twelve articles met our inclusion criteria, which resulted in a total of 315 patients. Six articles pertained to arthroscopic debridement (n = 249), 3 to microfracture (n = 47), 2 to osteochondral autograft transplantation (n = 15), and 1 to autologous chondrocyte implantation (n = 5). Whereas most studies reported favorable results, sample heterogeneity and differences in the use of functional and radiographic outcomes precluded a meta-analysis. Several positive and negative prognostic factors were identified. All of the eligible studies were observational, retrospective case series without control groups; the quality of evidence available for the use of the aforementioned procedures is considered "very low" and "any estimate of effect is very uncertain." More research is necessary to determine which treatment for chondral pathology in the shoulder provides the best long-term outcomes. We encourage centers to establish the necessary alliances to conduct blinded, randomized clinical trials and prospective, comparative cohort studies necessary to rigorously determine which treatments result in the most optimal outcomes. At this time, high-quality evidence is lacking to make strong recommendations, and decision making in this patient population is performed on a case-by-case basis. Level IV, systematic review of Level IV studies.

Repeated Platelet Concentrate Injections Enhance Reparative Response of Microfractures in the Treatment of Chondral Defects of the Knee: An Experimental Study in an Animal Model

To assess the histology and biomechanics of repair cartilage after microfractures with and without repeated local injections of platelet concentrate for the treatment of full-thickness focal chondral defects of the knee. A full-thickness chondral lesion on the medial femoral condyle was created in 30 sheep and treated with microfractures. Animals were divided into 2 groups, according to postoperative treatment: in group 1 we performed 5 weekly injections of autologous conditioned plasma, whereas group 2 did not undergo further treatments. Animals were killed at 3, 6, and 12 months after treatment. Macroscopic, histologic, and biomechanical evaluations were performed. Differences between groups at each time interval and differences over time within groups were analyzed for each outcome. Significance was set at P < .05. Group 1 showed significantly better macroscopic, histologic, and biomechanical results than group 2 at each time interval. Analysis of time effect within groups showed that in group 1, quality of repair tissue significantly improved from 3 to 6 months after treatment and remained stable over time for all the outcomes; in group 2 a significant histologic and mechanical deterioration was observed between 6 and 12 months' follow-up. Five repeated local injections of autologous conditioned plasma after microfractures in the treatment of full-thickness cartilage injuries promoted a better and more durable reparative response than isolated microfractures, although they did not produce hyaline cartilage. Periodical intra-articular injections of platelet concentrate after microfractures may improve cartilage repair and prevent further degenerative changes.

Bone marrow-derived mesenchymal stem cells versus bone marrow nucleated cells in the treatment of chondral defects

The aim of this study was to compare bone marrow-derived mesenchymal stem cells (MSCs) with bone marrow nucleated cells (BNCs) as seed cells in the treatment of cartilage defects. Twenty Guizhou minipigs were used to create full-thickness chondral defects of 6.0 mm in diameter in the knee joints and divided between two time points (four and eight weeks) for final assessment. At every time point, animals were separated into four groups: the CON group which underwent no implantation; the collagen type II hydrogel group (COL); the collagen type II hydrogel + bone marrow-derived MSCs group; and the collagen type II hydrogel + BNCs group. The samples were grossly examined, observed through a stereo microscope, histologically analysed and evaluated with the O'Driscoll scoring system, respectively. The cartilage repair of the two cell-treated groups was improved markedly compared to the CON and the COL groups, while the repair tissues of the two cell-treated groups showed no significant difference eight weeks after surgery. These data indicate that BNCs contribute to the repair of cartilage with collagen type II hydrogel as scaffolds, which have comparable results with bone marrow-derived MSCs. Moreover, the transplantation of autologous BNCs as seed cells may be a more economical and convenient technique for cartilage repair in clinical applications.

Paper # 98: Bone Marrow-Derived Culture-Expanded Mesenchymal Stem Cells in Conjunction with Microfracture to Treat Chondral Lesions in an Equine Model

ObjectiveMicrofracture is often the first choice treatment for chondral defects, but results might be enhanced. We tested the potential of bone marrow-derived culture-expanded mesenchymal stem cells (BMSC) to augment healing after full-thickness cartilage defects were microfractured. We hypothesized that the combined effects of intraarticular injection of autogenous BMSC with microfracture would enhance healing in full-thickness chondral defects compared to microfracture alone in an equine model.

A mathematical model of cartilage regeneration after cell therapy

Autologous Chondrocyte Implantation (ACI) is a cell-based therapy used mainly for the treatment of chondral defects in the knee. It involves surgically inserting isolated chondrocytes or mesenchymal stem cells (MSCs), previously expanded in culture, into the defect region. These chondrocytes then proliferate and migrate in the process forming extracellular matrix (ECM) and new cartilage. In the case of MSCs, the process of forming new cartilage is initiated only after differentiation of the stem cells into chondrocytes. Many details of the repair process following insertion in humans are unknown. To enable better understanding of the repair process, we present a mathematical model of cartilage regeneration after cell therapy. The key mechanisms involved in the regeneration process are simulated by modelling cell migration, proliferation and differentiation, nutrient diffusion and depletion, and ECM synthesis and degradation at the defect site, both spatially and temporally. The model successfully simulates the progression of cartilage regeneration. The model predicts a time frame of about 18 months for the defect to reach full maturation which corresponds with results from clinical studies and demonstrates that cartilage regeneration is a slow process. Moreover, the model also suggests that regeneration using stem cells alone is no better than that using chondrocytes. The stem cells need to first differentiate into chondrocytes before forming ECM and new cartilage, a process that is initiated only after the stem cell density exceeds a threshold value. Furthermore, with chondrocytes alone, the matrix seems to develop from the subchondral bone interface as compared to the normal cartilage interface, in the case of stem cells alone. The influence of initial conditions and parameters, such as the initial cell seeding densities and cell proliferation rates, is shown to not significantly influence the general evolution characteristics other than accelerating the initial growth process. The model presented here is a first approach towards better understanding of cartilage regeneration after cell therapy techniques.

Return to Play Following Arthroscopic Microfracture of the Hip in Elite Athletes (SS-40)

Introduction Microfracture technique has become increasingly popular among orthopaedic surgeons for the treatment of chondral defects in several joints due to its effectiveness, low cost, and ease of performance. Arthroscopic microfracture for full thickness chondral defects of the knee has been reported in elite athletes with good clinical outcomes and adequate return to sport percentages. Very few data have been reported regarding return to sport following arthroscopic microfracture in the hip in elite level athletes. Methods Forty-one elite level athletes were initially identified who underwent arthroscopic microfracture performed by a single surgeon (MJP) between 1999 and 2008. Thirty-four elite level athletes met the inclusion criteria of a discrete Outerbridge grade IV chondral lesion either on the femoral head (N=3), acetabulum (N=27), or both (N=4), which was amenable to microfracture, and had a desire to return to a professional career. Sports played at the elite level included hockey, soccer, football, baseball, tennis, and golf. All patients underwent concomitant labral debridement (N=8), repair (N=23), or reconstruction (N=3). Data were obtained including number of games played and number of seasons played at an elite level following arthroscopic microfracture. Results Seventy-nine percent (27 of 34) of elite athletes who underwent microfracture surgery returned to play at an elite level. Twenty-seven athletes returned to play for an average of 4 seasons following the index procedure (range: 1-11 seasons). Twenty-six (96%) athletes returned to play the same season or the season following the index procedure. The six of the seven athletes (2 soccer, 3 hockey, 1 baseball, 1 football) who did not return to play underwent a concomitant labral repair, and one underwent a labral reconstruction. Conclusion Professional athletes with a discrete, full thickness chondral defect of the hip are able to return to the elite level following an arthroscopic microfracture procedure. Microfracture technique has become increasingly popular among orthopaedic surgeons for the treatment of chondral defects in several joints due to its effectiveness, low cost, and ease of performance. Arthroscopic microfracture for full thickness chondral defects of the knee has been reported in elite athletes with good clinical outcomes and adequate return to sport percentages. Very few data have been reported regarding return to sport following arthroscopic microfracture in the hip in elite level athletes. Forty-one elite level athletes were initially identified who underwent arthroscopic microfracture performed by a single surgeon (MJP) between 1999 and 2008. Thirty-four elite level athletes met the inclusion criteria of a discrete Outerbridge grade IV chondral lesion either on the femoral head (N=3), acetabulum (N=27), or both (N=4), which was amenable to microfracture, and had a desire to return to a professional career. Sports played at the elite level included hockey, soccer, football, baseball, tennis, and golf. All patients underwent concomitant labral debridement (N=8), repair (N=23), or reconstruction (N=3). Data were obtained including number of games played and number of seasons played at an elite level following arthroscopic microfracture. Seventy-nine percent (27 of 34) of elite athletes who underwent microfracture surgery returned to play at an elite level. Twenty-seven athletes returned to play for an average of 4 seasons following the index procedure (range: 1-11 seasons). Twenty-six (96%) athletes returned to play the same season or the season following the index procedure. The six of the seven athletes (2 soccer, 3 hockey, 1 baseball, 1 football) who did not return to play underwent a concomitant labral repair, and one underwent a labral reconstruction. Professional athletes with a discrete, full thickness chondral defect of the hip are able to return to the elite level following an arthroscopic microfracture procedure.

The treatment of chondral and osteochondral defects of the knee with autologous matrix-induced chondrogenesis (AMIC): method description and recent developments

Articular resurfacing by treatment of chondral defects may include chondral abrasion, autologous chondrocyte Implantation (ACI), matrix-induced chondrocyte transplantation (MACT) or osteochondral autologous transplantation (OATS). This technical note describes the method of autologous matrix-induced chondrogenesis (AMIC), a one-step procedure combining subchondral microfracture with the fixation of a collagen I/III membrane with fibrin glue or sutures. This is a technical note on the AMIC procedure and its further development. This method is applied primarily in chondral or osteochondral lesions of the knee. Indications and contraindications are provided; the technique is described. The further development of AMIC is described with an increased focus on the subchondral zone and the complex of cartilage and bone, the osteochondral unit, which receives increased attention in cartilage research. IV.

Matrix-Associated and Autologous Chondrocyte Transplantation in the Ankle: Clinical and MRI Follow-up after 2 to 11 Years.

Background:New matrix-associated autologous chondrocyte transplantation (MACT) techniques may facilitate the treatment of chondral defects in talar cartilage and provide good clinical outcome in the long term. The aim of this prospective case series was to monitor the clinical outcome after autologous chondrocyte transplantation (ACT) and MACT in the ankle to gain data on the mid-term efficacy of the procedure.Methods:Seventeen cases of talar cartilage defects were assessed with the American Orthopaedic Foot and Ankle Score (AOFAS), a modified Cincinnati score, and a subjective ankle-hindfoot score (AHS) at a mean of 61 (24-135) months after surgery. Nine patients consented to an additional magnetic resonance imaging (MRI) exam, including T2 mapping at 3T. ACT was carried out with a periosteal flap (4 cases) or with a matrix-assisted ACT technique (Hyalograft C; 13 cases).Results:Significant improvement was found in all cases. The AOFAS improved from 50.0 to 87.3, the AHS from 43.8 to 84.1, and the modified Cincinnati score from 2.9 to 6.9. MRI data demonstrated good defect filling, and T2 mapping results indicated that the collagen and water content of the repair tissue was comparable to adjacent cartilage.Discussion:MACT and ACT in the ankle can provide good and excellent long-term outcome and resulted in repair tissue with T2 properties similar to native cartilage in the majority of cases. Matrix-assisted implantation with the hyaluronan matrix allows for a less invasive surgical procedure.Level of evidence:4; prospective case series study.

We do not have evidence based methods for the treatment of cartilage defects in the knee

The aim of this study was to perform a systematic review of studies concerning current treatment of chondral defects of the knee. The relevance for evidence based data and for successful surgical treatment of cartilage defects was evaluated. From 56,098 evaluated studies, 133 studies could be further pursued. These supplied data concerning microfracturing, the osteochondral autograft transplantation system (OATS), the autologous chondrocyte implantation (ACI) and the matrix induced chondrocyte implantation (MACI). The modified Coleman Methodical Score (CMS) and the Level of Evidence (LOE) were applied to evaluate the quality. In these studies, a total of 6,920 patients were reviewed with a median of 32 patients per study and a mean follow-up of 24months. The mean CMS was 58 of 100 points. No study reached 100 points in the CMS. Three studies reached a level above 90. Ten studies were Level I, five studies reached Level II. Seven studies reached Level III, 111 studies Level IV. MRI scans to verify the clinical data were used by only 72 studies. The means in the modified CMS were for the different procedures as follows: ACI 58 points, MACI 57 points, microfracturing 68 points and OATS 50 points. 24 studies applied the Lysholm Score (LS) for clinical evaluation of cartilage surgery. All operative procedures yielded comparable improvements of the LS (n.s.) meaning that no operative procedure proved superior. As the majority of studies evaluated by this review is insufficient for EBM purposes more coherent studies with LOE of I or II are needed. Co-relating the systems of CMS and LOE and validating the applied scores seems desirable.

Treatment of chondral defects of the knee with one step matrix-assisted technique enhanced by autologous concentrated bone marrow: In vitro characterisation of mesenchymal stem cells from iliac crest and subchondral bone

Cartilage repair is still an unsolved problem. In the last years many cell-based treatments have been proposed, in order to obtain good regeneration of cartilage defects. The Autologous Matrix-Induced Chondrogenesis technique (AMIC ®) combines the micro-fracture procedure with the use of a specific biological membrane. The phenotypic feature of bone marrow cell population, harvested from iliac crest and knee subchondral bone of patients treated with the AMIC ® technique, enhanced by autologous concentrated bone marrow, was analysed to evaluate potential variations of the cell population. Samples of eleven patients, with isolated chondral lesions grade III or IV were treated with the AMIC ® technique, enhanced by the use of autologous concentrated bone marrow. A small fraction of bone marrow samples, both from iliac crest and from the created micro-fractures, was analysed by FACS analysis and then cultured to verify their proliferative and differentiation potential. An average of 0.04% of concentrated bone marrow cells harvested from the iliac crest, presented mesenchymal stem cell phenotype (CD34 −/CD45 low/CD271 high), whereas just 0.02% of these cells were identified from the samples harvested during the creation of micro-fractures at the knee. After two passages in culture, cells expressed a peculiar profile for MSC. Only MSC from bone marrow could be long-term propagated and were able to efficiently differentiate in the cultures. Although the AMIC ® approach has many advantages, the surgical technique in the application of the microfracture technique remains essential and affects the final result.

Autologous chondrocyte implantation (ACI): an innovative technique for articular cartilage defects

Abstract Articular cartilage lesions can hardly be regenerated spontaneously in vivo, remain a challenging problem for orthopedic surgeons. Various techniques have been used to treat this pathology with variable success rates. In recent years, however, regenerative techniques, such as autologous chondrocyte implantation, have emerged as possible solutions for the treatment of chondral defects. The use of classic autologous chondro-cyte implantation (first generation) has been associated with several limitations. To overcome these problems, a recent powerful cell based tissue engineering therapy has developed, Chondron™ as a commercial product of third generation autologous chondrocyte implantation. It consists of mixture of biodegradable and biocompatible gel with in vitro cultured autologous chondrocytes. This procedure avoids the use of periosteal flap, further simplifies the surgical procedure with limited time of operation with an arthroscopic procedure. Thus, the surgical morbidity and the recovery time for the patient are extremely reduced with no complications related to septic conditions and periosteal flap. The clinical outcomes of Chondron™ ACI have shown positively significant results.

The effect of platelet rich plasma combined with microfractures on the treatment of chondral defects: an experimental study in a sheep model

To evaluate the effect of autologous platelet rich plasma (PRP) combined with microfractures on the treatment of chondral defects. The hypothesis of the study was that PRP can enhance cartilage repair after microfractures. A chronic full-thickness chondral lesion of the medial femoral condyle was performed in 15 sheep. Animals were divided into three groups, according to treatment: group 1: microfractures; group 2: microfractures+PRP and fibrin glue gel; group 3: microfractures+liquid-PRP injection. Animals were sacrificed at 6 months after treatment. Macroscopic appearance was evaluated according to International Cartilage Repair Society (ICRS) score; cartilage stiffness was analyzed with an electromechanical indenter (Artscan 200); histological appearance was scored according to a modified O'Driscoll score. Comparison between groups for each outcome was performed with Kruskal-Wallis test, and Tukey's test for pairwise comparisons. Macroscopic ICRS score of group 2 was significantly better than those of the other groups, and score of group 1 was significantly lower than those of the other groups. Scores of group 1 and 3 were significantly lower than that of normal cartilage. Mean cartilage stiffness of groups 1 and 3 was significantly lower than that of normal cartilage. Histological total scores of group 2 and 3 were significantly better than that of group 1. PRP showed a positive effect on cartilage repair and restoration after microfractures. The procedure was more effective when PRP was used as a gel in comparison with liquid intra-articular injection. Histological analysis revealed that none of experimental treatments produced hyaline cartilage.

Treatment of Chondral Defects in the Patellofemoral Joint

Patellofemoral disease is one of the most controversial management issues in orthopedic surgery. Nonoperative management as a prerequisite first line treatment is successful in the majority of cases. However, a small subset of patients with persistent pain after adequate rehabilitation will be potential candidates for surgical intervention. Careful assessment of the underlying pathomechanics is critical for a successful outcome; these include malalignment of the extensor mechanism, trochlear dysplasia, soft-tissue imbalance, and chondral damage. As the pathology is multifactorial, the planning and treatment must be multifaceted. With careful patient selection, the options of titrated limited lateral release, restoration of MPFL function, tibial tubercle osteotomy, cartilage repair, and patellofemoral resurfacing provide improved functionality and pain relief for the young patient suffering from patellofemoral pain.