Autologous Matrix-induced Chondrogenesis Research Articles

Mid-term results of autologous matrix-induced chondrogenesis for large chondral defects in hips with femoroacetabular impingement syndrome.

The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI). This single-centre study focused on a cohort of 24 patients with cam- or pincer-type FAI, full-thickness femoral or acetabular chondral lesions, or osteochondral lesions ≥ 2 cm2, who underwent surgical hip dislocation for FAI correction in combination with AMIC between March 2009 and February 2016. Baseline data were retrospectively obtained from patient files. Mid-term outcomes were prospectively collected at a follow-up in 2020: cartilage repair tissue quality was evaluated by MRI using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Patient-reported outcome measures (PROMs) included the Oxford Hip Score (OHS) and Core Outcome Measure Index (COMI). Clinical examination included range of motion, impingement tests, and pain. A total of 12 hips from 11 patients were included (ten males, one female, mean age 26.8 years (SD 5.0), mean follow-up 6.2 years (SD 5.2 months)). The mean postoperative MOCART score was 66.3 (SD 16.3). None of the patients required conversion to total hip arthroplasty. Two patients had anterior impingement. External hip rotation was moderately limited in four patients. There was a correlation between MOCART and follow-up time (rs = -0.61; p = 0.035), but not with initial cartilage damage, age, BMI, or imaging time delay before surgery. PROMs improved significantly: OHS from 37.4 to 42.7 (p = 0.014) and COMI from 4.1 to 1.6 (p = 0.025). There was no correlation between MOCART and PROMs. Based on the reported mid-term results, we consider AMIC as an encouraging treatment option for large cartilage lesions of the hip. Nonetheless, the clinical evidence of AMIC in FAI patients remains to be determined, ideally in the context of randomized controlled trials.

A randomized controlled trial demonstrating sustained benefit of autologous matrix-induced chondrogenesis (AMIC®) over microfracture: 10-year follow-up

A randomized controlled trial demonstrating sustained benefit of autologous matrix-induced chondrogenesis (AMIC®) over microfracture: 10-year follow-up

Enhancing precision in osteochondral lesions of the talus measurements and improving agreement in surgical decision-making using weight-bearing computed tomography and distance mapping.

Weight-bearing computed tomography (WBCT) enables the creation of a three-dimensional (3D) model that represents the ankle morphology in a standing position. Distance mapping (DM) is a complementary feature that uses color coding to represent the relative intraarticular distance and can be used to outline intraarticular defects. Consequently, DM offers a novel approach to delineating osteochondral lesions of the talus (OLT), allowing for the quantification of its surface, volume and depth. The reliability of DM for OLT measurements has yet to be thoroughly evaluated. This study primarily aims to determine the reliability of DM in measuring the surface, depth and volume of OLT. A secondary objective is to ascertain whether measurements obtained through DM, when integrated with a predefined treatment algorithm, can facilitate consensus among surgeons regarding the optimal surgical intervention. This cohort comprised 36 patients with 40 OLTs evaluated using WBCT and DM. Two raters used DM to determine the lesion boundary (LB) and lesion fundus (LF) and calculate the lesion depth, surface and volume. The raters were asked to choose between bone marrow stimulation, autologous matrix-induced chondrogenesis and osteochondral transposition based on the measurement. Inter-rater and intra-rater agreement was measured. Interclass correlation of the lesion's depth surface produced an excellent inter-rater and intra-rater agreement of 0.90-0.94 p < 0.001. Cohen's κ agreement analysis of the preferable preoperative plan produced a κ = 0.834, p < 0.001, indicating a near-perfect agreement. WBCT-based 3D modules and DM can be used to measure the lesion's surface, depth and volume with excellent inter-rater and inter-rater agreement; using this measurement and a predetermined treatment algorithm, a near-perfect inter-rater agreement for the preoperative planning was reached. WBCT in conjunction with AI capabilities could help determine the type of surgery needed preoperatively, evaluate the hindfoot alignment and assess if additional surgeries are needed. Level III.

Autologous matrix-induced chondrogenesis versus osteochondral autograft transfer system in patellar chondral lesions: a comparative study with a 2-year follow-up

ObjectivesTo compare functional outcomes between patients who had undergone surgical treatment with osteochondral autograft transfer system (OATS) or autologous matrix-induced chondrogenesis (AMIC) for patellar chondral lesions preoperatively and after a 2-year follow-up. DesignForty-six patients who underwent AMIC (n = 12) or OATS (n = 34), participated in this retrospective study. Outcome measures, including the Lysholm, Kujala, Fulkerson, and Tegner scores, were collected before surgery and 2 years after surgery. ResultsSex, age, laterality, or location of the patellar lesion were not significantly different between groups. The mean lesion size was greater in the AMIC group (2.18 cm2) than in the OATS group (1.13 cm2) (P < .001). There was no difference between groups in Lysholm, Fulkerson, and Kujala scores preoperatively, although the OATS group showed a more favorable Tegner score compared to the AMIC group (6.59 vs 3.45, P < .001). Postoperatively, the AMIC group had a higher mean Lysholm score than the OATS group, (88.3 vs 79.5, P = .025). Mean values of almost all clinical tests significantly increased at the end of the 2-year follow-up, in both groups, except for the Tegner score in the OATS group, which showed a mean reduction from 6.59 preoperatively to 5.47 postoperatively (P = .006). ConclusionOATS and AMIC are effective treatments for patellar chondral lesions, with sustainable results after a minimum follow-up period of 2 years. Patients who underwent AMIC had better clinical and functional outcomes than patients who underwent OATS for patellar chondral lesions during the follow-up period.

Significant Clinical Improvement After Arthroscopic Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus: A 5-Year Follow-Up.

This study aims to evaluate the clinical outcomes of arthroscopic autologous matrix-induced chondrogenesis (A-AMIC) for osteochondral lesions of the talus (OLT) at 24 months and 60 months of follow-up. The secondary aim was to assess whether age, body mass index (BMI), and lesion surface affect outcomes. Sixty-three patients (32 males, 31 females) with a median age of 37 years [interquartile range (IQR): 25-48] were included. Preoperative and postoperative (24 months and 60 months) clinical outcomes were evaluated using a Visual Analog Score (VAS) for pain during walking, the American Orthopaedic Foot and Ankle Society (AOFAS), Short-Form Survey (SF-12), the Halasi, and the University of California, Los Angeles (UCLA) scores. Patients were categorized according to age, BMI, and lesion surface (1-1.5 cm2 and over 1.5 cm2). The effect of each category was evaluated. There were significant improvements in the VAS, AOFAS, SF-12, and UCLA, comparing the preoperative scores to the 60-month follow-up scores (P < 0.001). There were no significant differences in the above-mentioned outcomes between the follow-up periods. Patients older than 33 years had lower SF-12, Halasi, and UCLA scores (P = 0.005, 0.004, and <0.001, respectively). Overweight patients had lower VAS, SF-12, Halasi, and UCLA scores (P = 0.006, 0.002, 0.024, and 0.007, respectively). Lesion size was uninfluential. A-AMIC yielded clinical improvements at a minimum follow-up of 60 months in patients with symptomatic OLTs, with clinical improvement peaking in the first 2 years, followed by a plateau period. Increased age and BMI were significantly associated with inferior outcomes.

Polysaccharide hybrid scaffold encapsulated endogenous factors for microfracture enhancement by sustainable release and cell recruitment

Autologous matrix-induced chondrogenesis improves microfracture (MF), but the lack of functional cells and factors inhibit a curative effect. Here, inspired by the healing process of wounds, we prepared a polysaccharide hybrid scaffold (HDCP) to immobilize endogenous growth factors (eGFs), which were derived from platelet-rich plasma (PRP). Compared with the absence of PRP, the hybrid cross-linking network endowed this scaffold with a denser pore structure, enhanced mechanical properties, and slower protein mass transfer rate, thus ensuring the long-term sustainable release of eGFs. In vitro studies confirmed that HDCP promoted bone marrow mesenchymal stem cell recruitment, proliferation, and chondrogenic differentiation. In vivo implantation indicated that HDCP regenerated a smooth articular cartilage surface with a regular fibrous matrix arrangement structure, and the mechanical strength of the regenerated cartilage considerably improved. The obvious MF enhancement implied that PRP and polysaccharide scaffold hybridization could be used as an implantable matrix for cartilage repair.

Repair of Bone Defect of the Talus with Calcaneus Autograft and Autologous Matrix-Induced Chondrogenesis: A Case Report

Background. The question of choosing a treatment strategy for full-thickness osteochondral defects of the tarsal bone remains relevant. When choosing a treatment strategy, two key points should be considered: restoring the architecture of the tarsal bone and achieving long-term restoration of cartilage-like coverage in the area of the osteochondral defect.&#x0D; Case report. A 34-year-old physically active patient sustained an ankle injury in 2011 and was treated conservatively. In 2020, he complained of pain and reduced activity. Initial assessment scores were: VAS (Visual Analog Scale) — 6 points, AOFAS-AHS (American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score) — 49 points, FAAM (Foot and Ankle Ability Measure) — 55 points. An MRI revealed an osteochondral defect in the medial part of the tarsal bone dome, measuring 16.4×9.4 mm and with a depth of 20.8 mm. The patient underwent the replacement of the bone defect with an autograft taken from the heel bone, using autologus matrix induced chondrogenesis (AMIC) procedure. After 6 months, a follow-up examination was performed, including ankle arthroscopy and removal of metal fixators. Arthroscopic findings showed that the chondroplasty area was almost identical to intact joint cartilage. One year after chondroplasty, the patient returned to his previous level of physical activity. Assessment scores were: VAS — 1 point, AOFAS-AHS — 94 points, FAAM — 83 points.&#x0D; Conclusion. The proposed method allows for the restoration of the architecture of the tarsal bone along with the cartilage surface. The use of a bone autograft helps to fill the tarsal bone defect, and covering the autograft with a collagen membrane contributes to the formation of hyaline-like cartilage tissue in the defect area.

Positive outcomes following Autologous Matrix-Induced Chondrogenesis (AMIC) in the treatment of retropatellar chondral lesions: a retrospective analysis of a patient registry

BackgroundThe patellofemoral joint is a challenging environment for treating chondral defects. Among the surgical options for the treatment of chondral defects, the single-stage Autologous Matrix-Induced Chondrogenesis (AMIC) procedure uses a porcine collagen I/III membrane to enhance bone-marrow stimulation. However, longer term outcomes data are rare for this specific indication. In order to provide real-world information, an ongoing registry has been established to record patient data and outcomes when AMIC is used to treat chondral and osteochondral lesions.MethodsPatient data were retrieved from an ongoing, prospective, multisite registry of patients who had undergone AMIC treatment of chondral defects. We identified 64 patients who had undergone AMIC for patellofemoral chondral defects and for whom pre-operative and at least 1 post-operative score were available were included in this retrospective data analysis. Outcomes were assessed via the KOOS, VAS pain, and the Lysholm scores. Outcomes at the post-operative time-points were analysed using a factorial ANOVA with post-hoc testing while linear regression was used to assess associations between the change in the Lysholm score and lesion size.ResultsThere was a significant improvement in Lysholm, VAS pain, and KOOS scores from pre-operative to the 1st year post-operative (p < 0.001), and this was maintained during the follow-up.ConclusionsThe forces exerted on the patellofemoral joint make this a challenging scenario for chondral repair. Our data demonstrates that the AMIC procedure with a collagen I/III membrane is an effective treatment for retropatellar cartilage lesions, and provides reliable results, with decreased pain and improved function. Importantly, these improvements were maintained through the follow-up period.

Mid-term results of impaction bone grafting and autologous matrix-induced chondrogenesis for knee osteochondral defects

Mid-term results of impaction bone grafting and autologous matrix-induced chondrogenesis for knee osteochondral defects

Does AMIC® provide improvements at least two years after surgery for knee osteochondral lesions? A multicentre retrospective study of 101 patients

BackgroundOsteochondral defects of the knee due to trauma or osteochondritis are associated with osteoarthritis in the medium term. Defects 2 to 8cm2 in size can be managed by autologous matrix-induced chondrogenesis (AMIC®), in which sub-chondral micro-fractures are created within the lesion and the defect is then covered by a matrix of type I and type III collagen to induce de novo cartilage formation. Although promising outcomes have been observed in small single-centre cohorts, the medium-term clinical and radiological effectiveness of AMIC® remains to be demonstrated in larger populations. The objective of this study was to evaluate outcomes of patients at least 2 years after AMIC® for knee osteochondral defects. HypothesisAMIC® is associated with clinical and radiological improvements after at least 2 years. Material and methodThis multicentre (16 centres), multisurgeon (18 senior orthopaedic surgeons), retrospective study included consecutive patients who underwent AMIC® with Chondro-Gide® membrane implantation between September 2011 and January 2020. The 36-item Short Form quality-of-life (SF-36) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) score were determined before the procedure and during follow-up. The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was assessed by magnetic resonance imaging 2 years after the procedure. ResultsIn total, 101 patients aged 12 to 60 years were included. Mean follow-up was 30 months. Mean defect size was 3.44cm2 (range, 2–8cm2). Significant improvements were documented in the SF-36 score, KOOS, and IKDC score. The mean MOCART score at 2 years was 75% (range, 20–100). DiscussionThe AMIC® procedure was associated with significant improvements at 2.5 years in patients treated for knee osteochondral defects measuring 2 to 8cm2. This method seems to provide similar outcomes to those of other available methods with the advantages of single-step surgery and elimination of osteochondral graft donor-site complications. Level of evidenceIV, retrospective observational cohort study.

Satisfactory patient-reported outcomes in patients treated with impaction bone grafting and autologous matrix-induced chondrogenesis for osteochondral knee defects.

Osteochondral knee defects usually affect young, active patients and may alter knee biomechanics and progressively lead to joint degeneration. Various treatment options exist with autologous, impaction bone grafting in combination with autologous matrix-induced chondrogenesis (BG-AMIC) being a less-expensive, one-step, promising option. The purpose of this study is to evaluate the clinical and radiological mid-term outcomes of large osteochondral lesions treated with BG-AMIC, identify a possible correlation between the two and report postoperative complications and reoperation rate. A retrospective analysis of 25 patients treated with the BG-AMIC technique for knee osteochondral lesions was performed. Patients were assessed using the following PROMs: the IKDC, the KOOS and the Lysholm score, the Tegner activity scale and a patient acceptable symptom state (PASS). TheEQ-5D-5L score was used to assess health-related quality of life. Radiological assessment was performed using the MOCART 2.0 score on a 3T MRI. At a mean of 3.8 (± 0.8)-year follow-up, all functional scores increased significantly (p < 0.005) when compared to the preoperative baseline. IKDC increased from 44.5 (± 15.9) to 81.4 (± 14.7), KOOS from 41.5 (± 16.1) to 91.6 (± 11.6) and Lysholm from 54.4 (± 23) to 95.2 (± 5.5) (p < 0.005). The EQ-5D-5L score also revealed a significant improvement [59.9 (± 25) to 93.4 (± 10.2), p < 0.005]. Mean Tegner score reached pre-injury levels. The PASS was positive in 100% of patients. The minimum clinically important difference was reached in all PROMs except for the KOOS Sports subscale. There were no re-operations. Morphological evaluation of the repair tissue using the MOCART 2.0 score revealed a mean total score of 52.8 (± 30.5). A statistically significant, positive correlation was found between the MOCART 2.0 score and the IKDC score, the KOOS ADL subscale and the EQ-5D-5L (p < 0.05). BG-AMIC is a safe and reliable option for treating deep, knee osteochondral lesions, providing a statistically significant and clinically important improvement in patient-reported outcomes. No complications were noticed, and no re-operations were performed after the procedure. A moderate positive correlation between the MOCART 2.0 score and the IKDC, KOOS ADL and EQ-5D-5L was noticed. However, this correlation is not necessarily clinically relevant, and excellent clinical results can be expected even in patients with low MOCART scores. III.

Magnetothermal spider silk-based scaffolds for cartilage regeneration

Developing biocompatible, magnetically controlled polymers is a multifunctional solution to many surgical complications. By combining nanoparticle technology with the latest advancements in polymer materials science, we created a multicomponent hybrid system comprised of a robust native spider silk-based matrix; a Mn0.9Zn0.1Fe2O4 nanoparticles coating to provide a controlled thermal trigger for drug release; and liposomes, which act as drug carriers. Fluorescent microscope images show that the dye loaded into the liposomes is released when the system is exposed to an alternating magnetic field due to heating of ferromagnetic nanoparticles, which had a low Curie temperature (40–46°С). The silk matrix also demonstrated outstanding biocompatibility, creating a favorable environment for human postnatal fibroblast cell adhesion, and paving the way for their directed growth. This paper describes a complex approach to cartilage regeneration by developing a spider silk-based scaffold with anatomical mechanical properties for controlled drug delivery in a multifunctional autologous matrix-induced chondrogenesis.

One-stage cartilage repair using the autologous matrix-induced chondrogenesis combined with simultaneous use of autologous adipose tissue graft and adipose tissue mesenchymal cells technique: clinical results and magnetic resonance imaging evaluation at five-year follow-up

PurposeTo evaluate medium-term outcomes of knee cartilage defects repair by autologous matrix-induced chondrogenesis combined with simultaneous use of autologous adipose tissue graft and adipose tissue mesenchymal cells, defined as LIPO-AMIC technique.MethodsThe LIPO-AMIC technique has been used in ICRS degree III–IV knee defects. Eighteen patients have been prospectively evaluated during two and five years both clinically and by MRI.ResultsPatients showed progressive significant improvement of all scores starting early at six months, and further increased values were noted till the last follow-up at 60 months. Mean subjective pre-operative IKDC score of 36.1 significantly increased to 86.4 at 24 months and to 87.2 at 60 months. Mean pre-operative Lysholm score of 44.4 reached 93.5 at two years and 93.5 at five years. MRI examination showed early subchondral lamina regrowth and progressive maturation of repair tissue and filling of defects. The mean total MOCART score showed that a significative improvement from two year follow-up (69.1 points) to last follow-up was 81.9 points (range, 30–100 points, SD 24). Complete filling of the defect at the level of the surrounding cartilage was found in 77.8%.ConclusionsAdipose tissue can represent ideal source of MSCs since easiness of withdrawal and definite chondrogenic capacity. This study clearly demonstrated the LIPO-AMIC technique to be feasible for treatment of knee cartilage defects and to result in statistically significant progressive clinical, functional and pain improvement in all treated patients better than what reported for the AMIC standard technique, starting very early from the 6-month follow-up and maintaining the good clinical results more durably with stable results at mid-term follow-up.

Mid-term results of autologous matrix-induced chondrogenesis surgery with or without scaffolds for arthroscopic treatment of deep talus osteochondral lesions: A comparative study.

This study aims to investigate the effectiveness of arthroscopic autologous matrix-induced chondrogenesis (AMIC) procedure with or without polyglycolic acid-hyaluronic acid (PGA-HA)-based cell-free scaffold (CFS) in Bristol Stage 4 and Stage 5 osteochondral lesion of the talus (OLT) ranging between 1.5 and 3 cm2 . Between March 2018 and March 2021, a total of 47 patients with OLTs (29 males, 18 females; mean age: 22.8±2.3 years; range, 18 to 65 years) were retrospectively analyzed. The patients were divided into two groups based on the procedures applied. Patients in the first group (Group 1, n=23) underwent the AMIC procedure alone (curettage, microfracture, and grafting), while patients in the second group (Group 2, n=24) underwent AMIC procedure with PGA-HA-based CFS. The localization of the lesions was evaluated. All OLTs were diagnosed with preoperative radiography and magnetic resonance imaging (MRI). During the preoperative period, lesion stages were evaluated based on the Bristol staging system, and the postoperative results were evaluated based on the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. The mean follow-up was 36.2±5.6 months. In the early period, the three-month functional scores were comparable between the groups. While a significant increase was observed in the American Orthopaedic Foot and Ankle Society (AOFAS) scores from the mean preoperative of 62.71±4.44 points to the postoperative of 86.00±6.58 points in Group 1, a significant increase in the AOFAS score was observed from 65.28±7.91 points to 95.42±4.41 points in Group 2 at 12-month follow-up (p=0.016, p=0.011, respectively). The functional scores tended to progress after 12 months. Radiologically, a complete defect filling was observed in a mean of 10.5±2.7 months. No graft hypertrophy was recorded in any patients. The AOFAS and MOCART scores in Group 2 were found to be statistically significantly higher than that in Group 1 (p=0.034 for AOFAS 1/AOFAS 2 and p=0.006 for MOCART 1/MOCART 2). Overall, there was a positive, but weak, significant correlation between the final AOFAS scores and MOCART scores (r=0.347, p<0.001). Arthroscopic AMIC procedure in deep OLTs between 1.5 cm2 and 3 cm2 can yield a statistically significant improvement both clinically and radiologically; however, the use of a PGA-HA-based CFS in addition to this procedure can improve the clinical and radiological recovery.

Outcomes of arthroscopy of the hip for femoroacetabular impingement based on intraoperative assessment using the Outerbridge classification.

Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system. A systematic search was performed on four databases. Studies which involved HA as the primary management of FAI and reported on chondral lesions as classified according to the Outerbridge classification were included. The study was registered on PROSPERO. Demographic data, patient-reported outcome measures (PROMs), complications, and rates of conversion to total hip arthroplasty (THA) were collected. A total of 24 studies were included with a total of 3,198 patients (3,233 hips). Patients had significantly less improvement in PROMs if they had Outerbridge grade III and IV lesions (p = 0.012). Compared with microfracture, autologous matrix-induced chondrogenesis (AMIC) resulted in significantly reduced rates of conversion to THA (p = 0.042) and of revision arthroscopy (p = 0.038). Chondral repair procedures in these patients also did not significantly reduce the rates of conversion to THA (p = 0.931), or of revision arthroscopy (p = 0.218). However, compared with microfracture, AMIC significantly reduced the rates of conversion to THA (p = 0.001) and of revision arthroscopy (p = 0.011) in these patients. Those with Outerbridge grade III and IV lesions also had significantly increased rates of conversion to THA (p = 0.029) and of revision arthroscopy (p = 0.023) if they had associated lesions of the acetabulum and femoral head. Those who underwent labral debridement had a significantly increased rate of conversion to THA compared with those who underwent labral repair (p = 0.015). There is universal improvement in PROMs following HA in patients with FAI and associated chondral lesions. However, those with Outerbridge grade III and IV lesions had significantly less improvement in PROMs and a significantly increased rate of conversion to THA than those with Outerbridge grade I and II. This suggests that the outcome of HA in patients with FAI and severe articular cartilage damage may not be favourable.

Surgical techniques for the articular cartilage repair: literature review and meta-analysis

Objective. To evaluate the clinical efficacy and safety of implementing the extracellular matrix (ECM), Autologous Matrix Induced Chondrogenesis (AMIC), adipose tissue derived mesenchymal stem cell (AD-MSCs), as well as bone marrow mesenchymal stem cells (BM-MSCs) for treating the osteochondral defects of knee joint and the talocrural one. Methods. Investigating by the facilities of PubMed, Embase and the manual searches, implemented from 2018 till January, 2022. There have been included articles with the І‒ІV level of evidence, studying the osteochondral defects over 0.5 сm2, with at least one-year duration of monitoring more than 10 patients, defining the scores on VAS (Visual Analogue Scale), Tegner Activity Scale, FAOS (Foot and Ankle Outcome Score). The results were evaluated after 1–2, 3–5 and over 5 years-period of monitoring. Meta-analysis was applied by the facilities of RStudio. Results. 14 investigations with 720 patients were incorporated. ECM, AMIC, AD-MSCs and BM-MSCs represented significantly better functional outcomes in comparison with the bone marrow stimulation procedures (MSP) on the VAS, Tegner Activity Scale, and FAOS scales. Patients treated according to the AMIC+BMAC (bone marrow aspirate concentrate) method showed better functional results compared to the standard AMIC technique. The rate of unsuccessful manipulations followed by revision operations in the MSP group is significantly higher than in others after 4 or more years of monitoring. The results obtained in a long-term investigation showed no deterioration after 5 years or more. Conclusions. Modern methods of cartilage repair in comparison with the creation of microfractures and microdrilling provide better quality regeneration, better long-term results, fewer complications, and higher rates of return to activity. Future studies should be longer-lasting and include more representative populations to determine the efficacy and safety of these methods.

Autologous surface repair: autologous matrix-induced chondrogenesis and minced cartilage implantation

<h2>ABSTRACT</h2><h3>Introduction</h3> The treatment of cartilage damage remains challenging. There are several procedures described. Microfracturing is considered one of the most established procedures, but long-term results are unsatisfactory, especially for larger defects. Autologous Matrix-Induced Chondrogenesis (AMIC), in which bone marrow-stimulated areas are covered with a membrane, has been introduced to address some of the limitations of microfracture with a number of long-term outcomes studies reporting satisfactory results. Minced cartilage Implantation (MCI), in which cartilage tissue is minced and inserted into cartilage defects has also been shown to have satisfactory results at 5-year results although longer-term results are still pending. <h3>Technique</h3> Both procedures can be performed arthroscopically. In the AMIC procedure, bone at the base of the chondral lesion is debrided to the subchondral plate and a bone marrow stimulation or microfracture is performed. Arthroscopic fluid is drained and the area covered with a membrane and fixed using fibrin glue or stiches either arthroscopically or using a mini-open approach. In MCI, the defect is also first debrided. Cartilage tissue removed from the affected joint is then cut into small pieces. In the open procedure, this is done with a scalpel; in the arthroscopic procedure, it is done with a shaver. The tissue is then inserted into the defcet and fixed using an allogeneic or autologous fibrin glue. <h3>Discussion</h3> AMIC and the minced cartilage technique represent a relatively simple, safe and reproducible evolution of cartilage repair techniques. Long-term studies (up to 9 years) support the satisfactory outcomes of the AMIC procedure. Five-year results for MCI procedure, report a decrease in pain and improved function, but long-term results are awaited. Well designed level one studies are now required to evaluate these techniqeus in the longer term.

Typical Complications After Cartilage Repair of the Ankle Using Autologous Matrix-Induced Chondrogenesis (AMIC).

Autologous matrix-induced chondrogenesis (AMIC) for the treatment of osteochondral lesions of the talus (OLT) results in favorable clinical outcomes, yet high reoperation rates. The aim of this study was to report and analyze typical complications and their risk factors after AMIC for OLT. A total of 127 consecutive patients with 130 AMIC procedures for OLT were retrospectively assessed. All AMIC procedures were performed in an open fashion with 106 (81.5%) cases requiring a malleolar osteotomy (OT) to access the OLT. Seventy-one patients (54.6%) underwent subsequent surgery. These cases were evaluated at a mean follow-up of 3.1 years (±2.5) for complications reviewing postoperative imaging and intraoperative findings during revision surgery. Six patients (8.5%) were lost to follow-up. Regression model analysis was conducted to identify factors that were associated with AMIC-related complications. Among the 65 (50%) patients who required revision surgery, 18 patients (28%) demonstrated AMIC-related complications with deep fissuring (83%) and thinning (17%) of the AMIC graft. Conversely, 47 patients (72%) underwent subsequent surgery due to AMIC-unrelated reasons including isolated removal of symptomatic hardware (n = 17) and surgery addressing concomitant pathologies with (n = 25) and without hardware removal (n = 5). Previous prior cartilage repair surgery was significantly associated with AMIC graft-associated complications in patients undergoing revision surgery (P = .0023). Among age, body mass index, defect size, smoking, and bone grafting, smoking was the only factor showing statistical significance with an odds ratio of 3.7 (95% CI 1.24, 10.9; P = .019) to undergo revision surgery due to graft-related complications, when adjusted for previous cartilage repair surgery. The majority of revision surgeries after AMIC for OLT are unrelated to the performed AMIC graft but frequently address symptomatic hardware and concomitant pathologies. Both smoking and previous cartilage repair surgery seem to significantly increase the risk of undergoing revision surgery due to AMIC-related complications. Level IV, case series.

Harvest and Application of Bone Marrow Aspirate Concentrate to Address Acetabular Chondral Damage During Hip Arthroscopy.

During hip arthroscopy, managing concomitant cartilage damage and chondrolabral junction breakdown remains an ongoing challenge for orthopaedic surgeons, as previous studies have associated such lesions with inferior postoperative outcomes1-7. Although higher-level studies are needed to fully elucidate the benefits, recent literature has provided supporting preliminary evidence for the utilization of bone marrow aspirate concentrate (BMAC) in patients with moderate cartilage damage and full-thickness chondral flaps undergoing acetabular labral repair7,8. Thus, as the incorporation of orthobiologics continues to advance, there is a clinical demand for an efficient and reliable BMAC-harvesting technique that utilizes an anatomical location with a substantial concentration of connective tissue progenitor (CTP) cells, while avoiding donor-site morbidity and minimizing additional operative time. Thus, we present a safe and technically feasible approach for harvesting bone marrow aspirate from the body of the ilium, followed by centrifugation and application during hip arthroscopy. After induction of anesthesia and appropriate patient positioning, a quadrilateral arrangement of arthroscopic portals is established to perform puncture capsulotomy9. Upon arthroscopic visualization of cartilage/chondrolabral junction injury, 52 mL of whole venous blood is promptly obtained from an intravenous access site and combined with 8 mL of anticoagulant citrate dextrose solution A (ACD-A). The mixture is centrifuged to yield approximately 2 to 3 mL of platelet-rich plasma (PRP) and 17 to 18 mL of platelet-poor plasma (PPP). Then, approaching along the coronal plane and aiming toward the anterior-superior iliac spine under fluoroscopic guidance, a heparin-rinsed Jamshidi bone marrow biopsy needle is driven through the lateral cortex of the ilium just proximal to the sourcil. Under a relative negative-pressure vacuum, bone marrow is aspirated into 3 separate heparin-rinsed 50 mL syringes, each containing 5 mL of ACD-A. Slow and steady negative pressure should be used to pull back on the syringe plunger to aspirate a total volume of 40 mL into each syringe. To avoid pelvic cavity compromise and minimize the risk of mobilizing marrow-space contents, care should be taken to ensure that no forward force or positive pressure is applied during the aspiration process. A total combined bone marrow aspirate/ACD-A mixture of approximately 120 mL is consistently harvested and subsequently centrifuged to yield roughly 4 to 6 mL of BMAC. The final mixture containing BMAC, PRP, and PPP is combined with thrombin to generate a megaclot, which is then applied to the central compartment of the hip. Currently, strategies to address acetabular cartilage lesions may include microfracture, autologous chondrocyte implantation, matrix-induced autologous chondrocyte implantation, autologous matrix-induced chondrogenesis, osteochondral allografts, and orthobiologics10. Orthobiologics have shown mixed yet promising results for addressing musculoskeletal injuries and may include bone-marrow-derived mesenchymal stromal cells, adipose tissue derivatives, and PRP7,8,11,12. Specifically, bone marrow aspirate can be harvested from numerous locations, such as the iliac crest, the proximal aspect of the humerus, the vertebral body, and the distal aspect of the femur. Moreover, alternative approaches have utilized multiple-site and/or needle-redirection techniques to optimize cellular yield16,17, while also appreciating the potentially variable cellular characteristics of aspirated and/or processed samples18. However, previous literature has demonstrated that the body of the ilium contains a CTP cell concentration that is similar to or greater than other harvest locations when utilizing this outlined single-site and unidirectional aspirating technique13,14. This versatile and updated technique is a safe and reproducible method for BMAC harvesting, processing, and application that avoids donor-site morbidity, obtains a substantial concentration of CTP cells, minimizes additional operative time, and limits the hip arthroscopy and aspiration to a single procedure15. Specifically, this technique details an evidence-supported approach to addressing chondral injury in patients undergoing acetabular labral repairs7,8. Patients with moderate cartilage damage treated with BMAC at the time of labral repair experienced significantly greater improvements in functional outcomes at 12 and 24 months postoperatively compared with similar patients without BMAC augmentation7. Furthermore, patients with full-thickness chondral flaps treated with BMAC at the time of arthroscopic labral repair demonstrated significantly greater improvements in functional outcomes at 12 months compared with microfracture. Moreover, 77.6% of the BMAC cohort reached the minimal clinically important difference threshold for the International Hip Outcome Tool-33 (iHOT-33) compared with 50.0% in the microfracture group8. Utilize the previously established Dienst arthroscopic portal for the bone marrow aspiration in order to avoid secondary donor site morbidity.Under fluoroscopic guidance, approach the ilium along the coronal plane, aiming toward the anterior superior iliac spine.With a heparin-rinsed Jamshidi bone marrow biopsy needle, penetrate the lateral cortex of the ilium just proximal to the sourcil in order to consistently harvest a total combined bone marrow aspirate/ACD-A volume of approximately 120 mL.Simultaneously perform the bone marrow aspirate and whole venous blood centrifugation during the hip arthroscopy procedure in order to minimize additional operative time.Bone marrow aspiration should be performed without applied traction in order to minimize the risk of neurovascular complications associated with extended traction time. ACD-A = anticoagulant citrate dextrose solution AADSCs = adipose-derived stem cellsASIS = anterior superior iliac spineBMAC = bone marrow aspirate concentrateCI = confidence intervalCTP = connective tissue progenitorDVT = deep vein thrombosisHOS-ADL = Hip Outcome Score, Activities of Daily LivingiHOT-33 = International Hip Outcome Tool-33MCID = minimal clinically important differenceMRA = magnetic resonance arthrogramMSCs = mesenchymal stromal cellsPPP = platelet-poor plasmaPRP = platelet-rich plasmaRBCs = red blood cellsSD = standard deviationT1 = longitudinal relaxation timeT2 = transverse relaxation timeWBCs = white blood cells.

Freiberg`s disease of lesser metatarsals treated with bone grafting and autologous matrix induced chondrogenesis (AMIC) membrane – A series of 10 cases

BackgroundFreiberg’s infraction is osteonecrosis of lesser metatarsal heads most commonly affecting adolescent females. They usually present with pain and swelling of the forefoot. MRI is useful investigation in the early diagnosis. It is a self-limiting disease and the main stay of treatment is non operative. Surgery is indicated in failed conservative management which include open debridement, cheilectomy, micro fracture, osteotomies and excision arthroplasty with varying success. MethodsA retrospective analysis of ten patients with Freiberg`s disease of the lesser metatarsals treated with open debridement, microfracture, bone grafting and application of AMIC (Autologous Matrix induced Chondroplasty) membrane was carried out. The patients were followed up to five years and the outcome measures were scored using Manchester-Oxford Foot Questionnaire (MOxFQ) and EQVAS best health scores. ResultsThe mean age was 42.7 years and follow-up time was 36.4 months. The most common site was second metatarsal, eight (80%) followed by third metatarsal, two (20%). The mean base line MOxFQ was 72.5 (95% CI- 45 ± 100) which improved to 42.5 (95%CI- 2.5 ± 82.5) at one year. The mean baseline VAS improved from 26.4(10.2 ± 42.6) to 30.3 (95%CI- 2.1 ± 58.5) at one year. The mean MOxFQ and VAS at the end of 36 months was 31.4(95%CI-6.6 ± 57.2) and47.3(4.3 ± 80.3) respectively. ConclusionsOpen debridement of the Freiberg`s disease combined with microfracture of the defect, bone grafting and application of AMIC membrane shows reliable functional and radiological outcomes at short term follow up.