Chitosan based scaffold applied in patellar cartilage lesions showed positive clinical and MRI results at minimum 2 years of follow up.

PURPOSE: New scaffold-based cartilage regeneration techniques have been developed to improve the results of microfractures also in complex locations like the patello-femoral joint. The aim of this study was to analyse the results obtained in patellar lesions treated with a bioscaffold,  a mixture composed by a chitosan solution, a buffer, and the patient's whole blood  which forms a stable clot into the lesion. METHODS: Fifteen patients with ICRS grade 3-4 cartilage lesions of the patellar surface were treated with a chitosan bioscaffold. Fourteen patients were clinically and radiologically evaluated prospectively for a minimum follow-up of 2 years with IKDC, KOOS, Tegner score, and MRI. The mean age of patients at the time of surgery was 31.8 ± 11.9 and nine patients presented degenerative aetiology, four patients with previous trauma, and 1 patient with osteochondritis dissecans.  RESULTS: The IKDC subjective score improved from 46.2 ± 19.3 preoperatively to 69.5 ± 20.3 (p < 0.05) and 74.1 ± 23.2 (p < 0.05) at 12 and 24 months, respectively. Also KOOS Pain, KOOS Sport/Rec and KOOS QOL showed a significant improvement from baseline to 12 months and to the final follow-up. MRI evaluation showed a complete filling of the cartilage defect at the final follow-up in 70% of the lesions, obtaining a total MOCART 2.0 score of 71.5 ± 13.6 at 24 months after surgery. CONCLUSION: Chondral patellar lesions represent a complex pathology, with lower results compared to other sites. This bioscaffold represents a safe surgical treatment providing a significant clinical improvement at 24 months in the treatment of patellar cartilage lesions. LEVEL OF EVIDENCE: IV.

Does Bone Marrow Edema Influence the Clinical Results of Intra-Articular Platelet-Rich Plasma Injections for Knee Osteoarthritis?

Platelet-rich plasma (PRP) is increasingly used for the intra-articular treatment of knee osteoarthritis (OA). However, clinical studies on PRP injections reported controversial results. Bone marrow edema (BME) can cause symptoms by affecting the subchondral bone and it is not targeted by intra-articular treatments. The aim of this study was to investigate if the presence of BME can influence the outcome of intra-articular PRP injections in knee OA patients. A total of 201 patients were included in the study, 80 with and 121 without BME at the baseline MRI. BME area and site were evaluated, and BME was graded using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Patients were assessed with International Knee Documentation Committee (IKDC) score Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, the EuroQol-Visual Analogue Scale (EQ-VAS), and the Tegner score at baseline, 2, 6, and 12 months. Overall, the presence of BME did not influence the clinical results of intra-articular PRP injections in these patients treated for knee OA. Patients with BME presented a similar failure rate and clinical improvement after PRP treatment compared to patients without BME. The area and site of BME did not affect clinical outcomes. However, patients with a higher BME grade had a higher failure rate.

Microfragmented Adipose Tissue Versus Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Prospective Randomized Controlled Trial at 2-Year Follow-up.

BACKGROUND: Intra-articular microfragmented adipose tissue (MF-AT) injections have been proposed for the treatment of knee osteoarthritis (OA). PURPOSE: To compare a single injection of MF-AT or platelet-rich plasma (PRP) in terms of clinical outcomes and OA progression. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 118 patients with symptomatic knee OA were randomized to receive a single intra-articular injection of MF-AT or PRP. Patients were evaluated before the injection and at 1, 3, 6, 12, and 24 months with the International Knee Documentation Committee (IKDC) subjective score, Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, EuroQol visual analogue scale (EQ-VAS), EuroQol 5 dimensions (EQ-5D), and visual analogue scale (VAS) for pain. Primary outcomes were the IKDC subjective score and the KOOS pain subscore at 6 months. Knees were evaluated at baseline and at 6, 12, and 24 months with radiography and high-resolution magnetic resonance imaging (MRI) using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). RESULTS: Both MF-AT and PRP provided a statistically and clinically significant improvement up to 24 months. The improvement in the IKDC subjective score from baseline to 6 months was similar in both MF-AT (41.1 ± 16.3 to 57.3 ± 18.8) and PRP (44.8 ± 17.3 to 58.4 ± 18.1) groups (P < .0005). The improvement in the KOOS pain subscore from baseline to 6 months was similar in both the MF-AT (58.4 ± 15.9 to 75.8 ± 17.4) and PRP (63.5 ± 17.8 to 75.5 ± 16.1) groups (P < .0005). Overall, no differences were found between the MF-AT and PRP groups in terms of clinical outcomes, adverse events (18.9% and 10.9%, respectively), and failures (15.1% and 25.5%, respectively). Radiographic and MRI findings did not show changes after the injection. As a secondary outcome, more patients in the MF-AT group with moderate/severe OA reached the minimal clinically important difference for the IKDC score at 6 months compared with the PRP group (75.0% vs 34.6%, respectively; P = .005). CONCLUSION: A single intra-articular injection of MF-AT was not superior to PRP, with comparable low numbers of failures and adverse events and without disease progression. No differences were found in clinical and imaging results between the 2 biological approaches.

A Comparison Between Polyurethane and Collagen Meniscal Scaffold for Partial Meniscal Defects: Similar Positive Clinical Results at a Mean of 10 Years of Follow-Up.

PURPOSE: To compare, at long-term follow-up, the clinical outcomes and failures of collagen and polyurethane meniscal scaffolds for the treatment of partial meniscal defects. METHODS: Patients affected by partial meniscal defect with intact anterior and posterior meniscal attachments and an intact rim at the circumference of the missing meniscus were included, treated with a collagen meniscal implant or with polyurethane scaffold, and clinically evaluated by analysis of the subjective International Knee Documentation Committee score, the visual analog scale score for the evaluation of knee function and symptoms, and the Tegner score to assess the activity level. RESULTS: After 3 patients dropped out, a total of 47 patients, comprising 31 men and 16 women, with a mean age of 43 ± 14.1 years and mean body mass index of 25 ± 1.4, were clinically evaluated up to a mean of 10 years' follow-up. The International Knee Documentation Committee score improved from 42.9 ± 15.9 to 67.4 ± 12.4 (P < .0005) in the polyurethane implant group and from 46.8 ± 16.7 to 62.1 ± 22.6 (P < .0005) in the collagen meniscal implant group. The visual analog scale score decreased significantly from baseline values of 5.4 ± 2.3 and 4.4 ± 1.7, to 3.4 ± 2.5 and 2.7 ± 2.4, respectively, at final follow-up in the polyurethane implant (P = .002) and collagen meniscal implant (P < .0005) groups. The Tegner score improved in both groups without reaching the preinjury activity level. No significant differences in the scores were found between the polyurethane and collagen scaffold groups. A total of 10 implants failed, 5 per group, for a cumulative failure rate of 21.3%, with no differences between the 2 scaffolds. CONCLUSIONS: The long-term comparison showed positive and similar results for both polyurethane- and collagen-based meniscal scaffolds, with an implant survival rate of about 80% at 10 years of follow-up and no differences in terms of pain, function, and activity level. LEVEL OF EVIDENCE: Level IV, case-control comparative study.

Bone marrow aspirate concentrate injections provide similar results versus viscosupplementation up to 24 months of follow-up in patients with symptomatic knee osteoarthritis. A randomized controlled trial.

PURPOSE: The purpose of this double-blind randomized controlled trial (RCT) was to compare clinical improvement and radiographic findings up to 2 years of follow-up of a single intra-articular injection of bone marrow aspirate concentrate (BMAC) versus hyaluronic acid (HA) for the treatment of knee osteoarthritis (OA). The hypothesis was that BMAC injection could lead to better clinical and radiographic results compared to viscosupplementation. METHODS: Patients with bilateral knee OA were randomized to one intra-articular injection of tibial-derived BMAC in one knee and one HA injection in the contralateral knee. Sixty patients were enrolled, and 56 were studied up to the final follow-up (35 men, 21 women, mean age 57.8 ± 8.9 years), for a total of 112 knees. Patients were evaluated before the injection and at 1, 3, 6, 12, and 24 months with the IKDC subjective score, VAS for pain, and the KOOS score. Minimal clinically important difference (MCID), patient treatment judgement, and adverse events were documented, as well as bilateral X-Rays (Rosenberg view) before and after treatment. RESULTS: No severe adverse events nor differences were reported in terms of mild adverse events (7.1% vs 5.4%, p = ns) and treatment failures (10.7% vs 12.5%, p = ns) in BMAC and HA groups, respectively. The IKDC subjective score improved from baseline to all follow-ups for BMAC (p < 0.0005), while it improved up to 12 months (p < 0.0005) and then decreased at 24 months (p = 0.030) for HA. Compared to HA, BMAC showed a higher improvement for VAS pain at 12 (2.2 ± 2.6 vs 1.7 ± 2.5, p = 0.041) and 24 months (2.2 ± 2.6 vs 1.4 ± 2.8, p = 0.002). The analysis based on OA severity confirmed this difference only in Kellgren-Lawrence 1-2 knees, while comparable results were observed in moderate/severe OA. Radiographic evaluation did not show knee OA deterioration for both treatment groups, without intergroup differences. CONCLUSION: BMAC did not demonstrate a clinically significant superiority at short-term compared to viscosupplementation, reporting overall comparable results in terms of clinical scores, failures, adverse events, radiographic evaluation, MCID achievement, and patient treatment judgment. However, while HA results decreased over time, BMAC presented more durable results in mild OA knees. LEVEL OF EVIDENCE: Level I.

Meniscus treatment: biological augmentation strategies: a narrative review.

Objective: An up-to-date description on the biological augmentation strategies for meniscal repair procedures was performed to highlight the main preclinical and clinical evidence available in the literature. Background: Meniscal repair is a key surgical procedure to preserve as much meniscal tissue as possible to limit the development of knee osteoarthritis (OA). Unfortunately, the results of meniscal repair procedures are not always satisfactory, reporting an overall risk of failure of 25%, likely conditioned due to the poor vascularization of the meniscal tissue. For this reason, several biologic augmentation techniques have been developed to improve the meniscal healing process, ranging from mechanical stimulations to biological products. Methods: A literature review was conducted on the main biological augmentation procedures combined to the meniscal repair process. A description of the rationale, surgical technique, and preclinical and clinical evidence was performed. Conclusions: Mechanical stimulations and fibrin clot were the first techniques applied showing several limitations and not exciting results. Recently, platelet-rich plasma (PRP) augmentation to meniscal repair is slowly spreading in the clinical practice. Early evidence from comparative studies showed a significantly lower failure rate in patients treated with PRP augmentation compared with controls. Conversely, the current few and low-level data on mesenchymal stem/stromal cells (MSCs) for meniscal augmentation repair make this a promising but anecdotal topic. Further high-quality clinical studies are needed to support and guide the use of biological strategies for the augmentation of meniscus repair, PRP.

Multi-layer cell-free scaffolds for osteochondral defects of the knee: a systematic review and meta-analysis of clinical evidence.

PURPOSE: The aim of this study was to analyze the clinical results provided by multi-layer cell-free scaffolds for the treatment of knee osteochondral defects. METHODS: A systematic review was performed on PubMed, Web of Science, and Cochrane to identify studies evaluating the clinical efficacy of cell-free osteochondral scaffolds for knee lesions. A meta-analysis was performed on articles reporting results of the International Knee Documentation Committee (IKDC) and Tegner scores. The scores were analyzed as improvement from baseline to 1, 2, and ≥ 3 years of follow-up. The modified Coleman Methodology Score was used to assess the study methodology. RESULTS: A total of 34 studies (1022 patients) with a mean follow-up of 35 months was included. Only three osteochondral scaffolds have been investigated in clinical trials: while TruFit® has been withdrawn from the market for the questionable results, the analysis of MaioRegen and Agili-C™ provided clinical improvements at 1, 2, and ≥ 3 years of follow-up (all significantly higher than the baseline, p < 0.05), although with a limited recovery of the sport-activity level. A low rate of adverse events and an overall failure rate of 7.0% were observed, but the overall evidence level of the available studies is limited. CONCLUSIONS: Multi-layer scaffolds may provide clinical benefits for the treatment of knee osteochondral lesions at short- and mid-term follow-up and with a low number of failures, although the sport-activity level obtained seems to be limited. Further research with high-level studies is needed to confirm the role of multi-layer scaffold for the treatment of knee osteochondral lesions.

Biologic Augmentation Reduces the Failure Rate of Meniscal Repair: A Systematic Review and Meta-analysis.

BACKGROUND: Clinical results after isolated meniscal repair are not always satisfactory, with an overall failure rate of around 25%. To improve the success rate of meniscal repair, different biologic augmentation techniques have been introduced in clinical practice, but their real efficacy is still controversial. PURPOSE/HYPOTHESIS: To evaluate the safety, clinical results, and failure rate of biologic augmentation techniques for meniscal repair. The hypothesis was that biologic augmentation would improve the results of meniscal repair. STUDY DESIGN: Systematic review and meta-analysis of comparative studies. METHODS: A systematic review of the literature was performed in March 2020 of 3 electronic databases (PubMed, Scopus, and the Cochrane Library) regarding meniscal repair combined with biologic augmentation techniques. Articles combining biologic augmentation with other surgical procedures besides meniscal suture were excluded. The quality of the included studies was assessed using a modified Coleman Methodology Score, and the risk of bias was evaluated using the ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) and the RoB 2.0 (Revised Tool for Risk of Bias in Randomized Trials) for nonrandomized and randomized controlled trials, respectively. RESULTS: A total of 11 studies were included in the qualitative analysis: platelet-rich plasma (PRP) augmentation in 6 comparatives studies, fibrin clot augmentation in 2 case series, and mesenchymal stem cells augmentation in 2 case series and 1 case report. One severe adverse event of septic arthritis was reported for PRP 1 month after surgery. The quality of evidence evaluated with the modified Coleman Methodology Score was low overall. Five studies reporting on 286 patients (111 PRP augmentation, 175 control) were included in the quantitative synthesis. A significantly lower risk of failure was documented in the PRP augmentation group as compared with the control group: 9.9% (4.5%-19.1%) versus 25.7% (12.7%-38.7%) (P < .0005). CONCLUSION: The literature on biologic meniscal augmentation is recent and scarce. Only a few comparative trials are available, all focusing on the potential of PRP. The meta-analysis documented that PRP is safe and useful in improving the survival rate, with a 9.9% rate of failure versus 25.7% for the control group. Further high-level studies are needed to confirm these findings and identify the most effective biologic augmentation strategy to improve the outcome of meniscal repair.

Matrix-assisted chondrocyte transplantation with bone grafting for knee osteochondritis dissecans: stable results at 12 years.

PURPOSE: To document clinical and radiological results of arthroscopic matrix-assisted autologous chondrocyte transplantation (MACT) combined with bone grafting for the treatment of knee osteochondritis dissecans (OCD) at long-term follow-up. METHODS: Thirty-one knees in 29 patients (20.4 ± 5.7 years) were treated for symptomatic unfixable OCD lesions (2.6 ± 1.1 cm2) and prospectively evaluated at 2, 5, and 12 years (average, minimum 10 years). Patients were evaluated over time with IKDC subjective score, EQ-VAS, and Tegner scores. Failures were also documented. At the final follow-up, MRI evaluation was performed in 14 knees with the MOCART 2.0 score. RESULTS: Beside 4 early failures, an overall clinical improvement was documented: the IKDC subjective score improved from 39.9 ± 16.8 to 82.1 ± 17.0 and 84.8 ± 17.2 at 2 and 5 years, respectively (p < 0.0005), and remained stable for up to 12 years (85.0 ± 20.2). EQ-VAS and Tegner scores presented similar trends, but patients did not reach their original activity level. Worse results were obtained for lesions bigger than 4 cm2. At MRI evaluation, subchondral bone abnormalities were detected in over 85% of knees at long-term follow-up. CONCLUSIONS: Arthroscopic bone grafting followed by MACT for unfixable knee OCD can offer a promising and stable clinical outcome over time in lesions smaller than 4 cm2, with a low failure rate of 13%. Persistent subchondral alterations were documented at long-term MRI evaluation, suggesting the limits of this approach to regenerate the osteochondral unit in patients affected by knee OCD. LEVEL OF EVIDENCE: IV.

Outpatient total knee arthroplasty leads to a higher number of complications: a meta-analysis.

BACKGROUND: Careful pre- and post-operative management can allow surgeons to perform outpatient TKA, making this a more affordable procedure. The aim of the present meta-analysis is to compare outpatient and inpatient TKA. METHODS: A systematic search of the literature was performed in July 2020 on PubMed, Web of Science, Cochrane library, and on the grey literature databases. The papers collected were used for a meta-analysis comparing outpatient and inpatient TKA in terms of complication and readmission rates. Risk of bias and quality of evidence were defined according to Cochrane guidelines. RESULTS: The literature search resulted in 4107 articles; of these, 8 articles were used for the meta-analysis. A total of 212,632 patients were included, 6607 of whom were TKA outpatients. The overall complication rate for outpatient TKAs was 16.1%, while inpatient TKAs had an overall lower complication rate of 10.5% (p = 0.003). The readmission rate was 4.9% in outpatient TKAs and 5.9% in inpatient TKAs. Only 3 studies reported the number of deaths, which accounted for 0%. The included studies presented a moderate risk of bias, and according to GRADE guidelines, the level of evidence for complications and readmissions was very low. CONCLUSIONS: This meta-analysis documented that outpatient TKA led to an increased number of complications although there were no differences in the number of readmissions. However, future high-level studies are needed to confirm results and indications for the outpatient approach, since the studies currently available have a moderate risk of bias and a very low quality of evidence.