Swarms of Enzyme-Powered Nanomotors Enhance the Diffusion of Macromolecules in Viscous Media.

Over the past decades, the development of nanoparticles (NPs) to increase the efficiency of clinical treatments has been subject of intense research. Yet, most NPs have been reported to possess low efficacy as their actuation is hindered by biological barriers. For instance, synovial fluid (SF) present in the joints is mainly composed of hyaluronic acid (HA). These viscous media pose a challenge for many applications in nanomedicine, as passive NPs tend to become trapped in complex networks, which reduces their ability to reach the target location. This problem can be addressed by using active NPs (nanomotors, NMs) that are self-propelled by enzymatic reactions, although the development of enzyme-powered NMs, capable of navigating these viscous environments, remains a considerable challenge. Here, the synergistic effects of two NMs troops, namely hyaluronidase NMs (HyaNMs, Troop 1) and urease NMs (UrNMs, Troop 2) are demonstrated. Troop 1 interacts with the SF by reducing its viscosity, thus allowing Troop 2 to swim more easily through the SF. Through their collective motion, Troop 2 increases the diffusion of macromolecules. These results pave the way for more widespread use of enzyme-powered NMs, e.g., for treating joint injuries and improving therapeutic effectiveness compared with traditional methods.

The HAR-index: a reliable method for evaluating the risk of total hip arthroplasty conversion after hip arthroscopy for femoroacetabular impingement.

PURPOSE: Hip arthroscopy is a growing technique in the treatment of femoroacetabular impingement (FAI), but can sometimes lead to unsatisfactory results such as the early conversion to total hip arthroplasty (THA). The purpose of this study is to describe a new tool for assessing the preoperative risk of THA conversion after hip arthroscopy in patients with FAI. METHODS: This study is a retrospective analysis of a prospective cohort of 584 patients with FAI who underwent hip arthroscopy at a single centre with a minimum 2 years follow-up. The preoperative variables of these patients were analysed to calculate the risk of each variable for THA. By selecting variables with an area under the receiver operating characteristic (ROC) curve greater than 0.7, a calculator was created to provide a risk index for each patient. RESULTS: Four variables (age, body mass index, Tönnis score and ALAD) were associated with an increased risk of THA conversion. The optimal cut-off points for each variable were determined, and a risk index was created. The Hip-Arthroplasty-Risk Index (HAR-Index) is a 0-4 points scale obtained from four binary scores of 0 or 1 depending on whether the cut-off point for each variable was reached or not. The increased risk of THA for each HAR-Index value was 1.1%, 6.2%, 17.9%, 55.1% and 79.3% respectively. The HAR-Index showed a very good predictive capacity with an area under the ROC curve of 0.89. CONCLUSION: The HAR-Index is a simple and practical tool for practitioners to make more informed decisions about performing hip arthroscopy in patients with FAI. With a very good predictive capacity, the HAR-Index can help to reduce the rate of conversion to THA. LEVEL OF EVIDENCE: Level III.

The Dual-Responsive Interaction of Particulated Hyaline Cartilage and Plasma Rich in Growth Factors (PRGF) in the Repair of Cartilage Defects: An In Vitro Study.

The treatment of chondral and osteochondral defects is challenging. These types of lesions are painful and progress to osteoarthritis over time. Tissue engineering offers tools to address this unmet medical need. The use of an autologous cartilage construct consisting of hyaline cartilage chips embedded in plasma rich in growth factors (PRGF) has been proposed as a therapeutic alternative. The purpose of this study was to dig into the potential mechanisms behind the in vitro remodelling process that might explain the clinical success of this technique and facilitate its optimisation. Chondrocyte viability and cellular behaviour over eight weeks of in vitro culture, type II collagen synthesis, the dual delivery of growth factors by hyaline cartilage and PRGF matrix, and the ultrastructure of the construct and its remodelling were characterised. The main finding of this research is that the cartilage fragments embedded in the three-dimensional PRGF scaffold contain viable chondrocytes that are able to migrate into the fibrin network, proliferate and synthesise extracellular matrix after the second week of in vitro culture. The characterization of this three-dimensional matrix is key to unravelling the molecular kinetics responsible for its efficacy.

Hip arthroscopy is a successful treatment for femoroacetabular impingement in under-16 competitive football players: a prospective study with minimum 2-year follow-up.

INTRODUCTION: Femoroacetabular impingement is considered a spectrum disease affecting multiple hip structures and it is especially prevalent in football players. Hip arthroscopy has shown good results in this population. However, little attention has been given to its efficacy in children and adolescent players. The aim of this study is to evaluate the outcomes of hip arthroscopy in under-16 football players. MATERIALS AND METHODS: Between 2008 and 2019, all under-16 competitive football players who underwent hip arthroscopy for the treatment of femoroacetabular impingement were recruited for this prospective study. Hip pain and function were measured through the VAS, HOS, mHHS and WOMAC scores before the surgery, at 1-year after the surgery and at minimum 2-years after surgery. Preoperative and postoperative scores were compared to  establish the evolution of hip pain and function. Additionally, rate and time to return to play were recorded. RESULTS: 14 subjects were included in the analysis. All subjects attended to the last follow-up, at mean 3.21 years after the surgery (range 2-10). Mean ± SD VAS (0-100) scores were 60.14 ± 15.88 before the surgery, 6.43 ± 5.19 at 1-year follow-up and 5.07 ± 4.05 at final follow-up (p < 0.05). Significant improvements were observed in HOS ADL, HOS SS, mHHS and WOMAC (p < 0.05) between preoperative values and 1-year follow-up. No significant differences were found in knee pain or function between 1-year and final follow-up assessments (p > 0.05). All subjects (100%) were playing football 1-year after the surgery, with a mean ± SD time to return to play of 5.93 ± 2.09 months. 13 subjects (92.86%) were still playing at final follow-up. CONCLUSIONS: Hip arthroscopy is a safe and effective surgical procedure for the treatment of FAI in under-16 competitive football players, improving hip pain and function with excellent rates to return to play.

Arthroscopic resection as a rapid recovery treatment for Os acetabuli in soccer players who had undergone hip arthroscopy: a case series with 1-year follow-up.

INTRODUCTION: Os acetabuli (OSA) is defined as a radiopaque structure located around the acetabular rim highly related to Femoroacetabular Impingement (FAI). Its treatment depends on the perspective of post-surgical joint instability. Ossicle resection is recommended if the femoral head is covered enough by the labrum. Previous research has described the results of this technique in general population. The aim of this study is to describe the outcomes and the time and rate of return to play (RTP) after hip arthroscopy and OSA removal in soccer players. METHODS: This study is a retrospective analysis of a prospective database containing all the consecutive soccer players who had undergone hip arthroscopy between 2018 and 2019. The subjects diagnosed with OSA and a center-edge angle (CEA) > 25 ° were included in the analysis. All the patients were treated with arthroscopic removal of the OSA and femoral osteoplasty. Hip function was assessed using the Modified Harris Hip Score (MHHS) before and at 3 and 12 months after surgery. Rate of RTP and competitive level at RTP were assessed at a 1-year follow-up. RESULTS: Between 2018 and 2019, 90 soccer players were treated with hip arthroscopy in our facilities. Six of them (6.6%) were diagnosed with OSA. Mean (SD) MHHS values were 69.7 (12.1) before the surgery, 89.7 (6.7) at 3 months post-surgery and 95.7 (5.1) at 12 months post-surgery. All the subjects reported significant improvements in their MHHS scores at 3 and 12 months post-surgery compared with pre-surgery levels (p < 0.01). Non-significant differences were found between 3 and 12 months post-surgery (p > 0.05). All the subjects (100%) returned to previous competitive levels. CONCLUSIONS: After surgery, all the soccer players returned to previous competitive level. Preoperative MHHS improved significantly at 3 months maintained for up to 12 months.

Treatment of Aneurysmal Bone Cyst with Endoscopic Resection and Bone Allograft with Platelet-Rich Plasma: A Case Report.

An aneurysmal bone cyst (ABC) is a rare bone tumor usually observed in long bones. The surgical treatment of this pathology is often related to high recurrence rates, so novel biological techniques can help to enhance tissue regeneration and bone consolidation. We present a case of a patient with ABC of the calcaneus treated with an endoscopic resection followed by grafting with an autologous-based matrix composed of allograft bone chips and autologous platelet-rich plasma (PRP) in semisolid and liquid states. Patient demonstrated excellent defect filling in both magnetic resonance imaging and radiologic exams and returned to pre-injury activity with no recurrence at 2 years follow-up. Endoscopic curettage together with allograft bone and autologous PRP is effective in treating ABC patients and could be a good adjuvant treatment to prevent reinjury and enhance consolidation.

Particulated Autologous Chondral-Platelet-Rich Plasma Matrix Implantation (PACI) for Treatment of Full-Thickness Cartilage Osteochondral Defects.

Articular hyaline cartilage injuries can occur as a result of either traumatic of progressive degeneration. When the articular cartilage in a joint is damaged, it can cause joint pain and dysfunction, predisposing patients for the development of early-onset osteoarthritis. There are many restoration procedures available to treat these injuries, such as bone marrow-stimulation techniques, osteoarticular auto/allograft transplants, and autologous chondrocyte implantation. Each of these techniques has its own limitations, which led researchers to explore new regenerative and repair techniques to produce normal hyaline cartilage. The purpose of this Technical Note is to describe in detail the particulated autologous chondral-platelet-rich plasma matrix implantation (PACI) technique that could be used as a single-stage cartilage restoration procedure for treatment of full-thickness cartilage and osteochondral defects.

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

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

Effects of autologous adipose-derived regenerative stem cells administered at the time of anterior cruciate ligament reconstruction on knee function and graft healing.

PURPOSE: To compare the healing and clinical outcomes of anterior cruciate ligament (ACL) reconstruction between patients with or without intraoperative administration of adipose-derived regenerative stem cells (ADRC). METHODS: Between 2013 and 2014, the outcomes of 20 soccer players undergoing ACL reconstruction using bone-patellar tendon-bone autograft infiltrated with ADRC at the end of the procedure were compared to a historical, matched cohort of 19 soccer players undergoing the same procedure without ADRC. Outcomes were obtained at baseline, and 6 and 12 months postop for IKDC (International Knee Documentation Committee), Lysholm, and Lequesne, and at 2, 4, 6, and 12 months postop for VAS (visual analogue scale) for pain and graft maturation to evaluate the ligamentization process (magnetic resonance imaging (MRI)-based). RESULTS: Both groups significantly improved the IKDC (p < 0.001 in both groups), Lysholm (p < 0.001 in both groups), Lequesne index (p < 0.001 in both groups), VAS for pain (p = 0.002 for the ADRC and p < 0.001 for the control group), and MRI scores (p < 0.001 in both groups) in the 12 months postop compared to baseline scores. However, there were no significant differences in the improvement of the outcomes between groups across time (p > 0.05). All patients returned to sports after surgery, but 8 (40%) patients in the ADRC and 13 (68.4%) patients in the control group had lower Tegner activity score at 12 months postop. CONCLUSIONS: Patients receiving ADRC at the time of ACL reconstruction significantly improved knee function and healing/maturation of the graft at 12 months. However, this improvement was not statistically significant compared to a control group undergoing ACL reconstruction alone.

Treatment of Knee Osteochondral Lesions Using a Novel Clot of Autologous Plasma Rich in Growth Factors Mixed with Healthy Hyaline Cartilage Chips and Intra-Articular Injection of PRGF.

Knee cartilage or osteochondral lesions are common and challenging injuries. To date, most symptomatic lesions warrant surgical treatment. We present two cases of patients with knee osteochondral defects treated with a one-step surgical procedure consisting of an autologous-based matrix composed of healthy hyaline cartilage chips, mixed plasma poor-rich in platelets clot, and plasma rich in growth factors (PRGF). Both patients returned to playing soccer at the preinjury activity level and demonstrated excellent defect filling in both magnetic resonance imaging and second-look arthroscopy (in one of them). The use of a clot of autologous plasma poor in platelets with healthy hyaline cartilage chips and intra-articular injection of plasma rich in platelets is an effective, easy, and cheap option to treat knee cartilage injuries in young and athletic patients.