Partial meniscectomy patients have a greater likelihood for the development of early osteoarthritis (OA). To prevent the onset of early OA, patient-specific treatment algorithms need to be created that predict patient risk to early OA after meniscectomy. The aim of this work was to identify patient-specific risk factors in partial meniscectomy patients that could potentially lead to early OA. Partial meniscectomy patients operated between 01/2017 and 12/2019 were evaluated in the study (n=317). Exclusion criteria were other pathologies or surgeries for the evaluated knee and meniscus (n = 114). Following informed consent, an online questionnaire containing demographics and the “Knee Injury and Osteoarthritis Outcome Score” (KOOS) questionnaire was sent to the patient. Based on the KOOS pain score, patients were classified into “low” (> 75) and “high” (< 75) risk patients, indicating risk to symptomatic OA. The “high risk” patients also underwent a follow-up including an MRI scan to understand whether they have developed early OA. From 203 participants, 96 patients responded to the questionnaire (116 did not respond) with 61 patients considered “low-risk” and 35 “high-risk” patients. Groups that showed a significant increased risk for OA were patients aged > 40 years, females, overweight (BMI >25 kg/m2 ≤ 30 kg/m2), and smokers (*p < 0.05). The “high-risk”-follow-up revealed a progression of early osteoarthritic cartilage changes in seven patients, with the remaining nineteen patients showing no changes in cartilage status or pain since time of operation. Additionally, eighteen patients in the high-risk group showed a varus or valgus axis deviation. Patient-specific factors for worse postoperative outcomes after partial meniscectomy and indicators for an “early OA” development were identified, providing the basis for a patient-specific treatment approach. Further analysis in a multicentre study and computational analysis of MRI scans is ongoing to develop a patient-specific treatment algorithm for meniscectomy patients

This study was proposed to evaluate the efficacy of fibrin clot augmentation in meniscal tear using inside-out meniscal repair. A total of 35 patients with meniscus tears were operated on with inside-out meniscus repair and fibrin clot augmentation. Patients were evaluated preoperatively and postoperatively with clinical criteria, Lysholm knee scoring system, and MRI. Out of the total 35 cases, 5 cases were lost to follow up. Clinical improvement was observed in 29 out of 30 patients (96.6%). The mean Lysholm score improved significantly from 67.63 ± 6.55 points preoperatively to 92.0 ± 2.9 points postoperatively (P < 0.05) in 2 years follow-up. Follow-up MRI in all patients revealed complete healing except in 1 case where the patient presented with recurrence of symptoms such as pain and locking which resolved with partial meniscectomy. Paraesthesia in the anterior part of the knee was observed in 2 cases. (6.6%). We conclude that fibrin clot augmentation is a good cost-effective modality of treatment for repairable meniscus tears to preserve the meniscus and decrease the point contact pressure on the condyles which may prevent the early occurrence of osteoarthritis

Meniscus tears have been treated using partial meniscectomy to relieve pain in patients, although this leads to the onset of early osteoarthritis (OA). Cell-based therapies can help preserve the meniscus, although the presence of inflammatory cytokines compromises clinical outcomes. Anti-inflammatory drugs (e.g. celecoxib), can help to reduce pain in patients and in vitro studies suggest a beneficial effect on cytokine inhibited matrix content. Previously, we have demonstrated that the inhibitory effects of IL-1β can be countered by culture under low oxygen tension or physioxia. The present study sought to understand whether physioxia, celecoxib or combined application can counter the inhibitory effects IL-1β inhibited meniscus cells. Human avascular and vascular meniscus cells (n =3) were isolated and expanded under 20% (hyperoxia) or 2% (physioxia) oxygen. Cells were seeded into collagen scaffolds (Geistlich, Wolhusen) and cultured for 28 days either in the presence of 0.1ng/mL IL-1β, 5µg/mL celecoxib or both under their expansion oxygen conditions. Histological (DMMB, collagen I and collagen II immunostaining), GAG content and gene expression analysis was evaluated for the scaffolds. Under hyperoxia, meniscus cells showed a significant reduction in GAG content in the presence of IL-1β (*p < 0.05). Celecoxib alone did not significantly increase GAG content in IL-1β treated cultures. In contrast, physioxic culture showed a donor dependent increase in GAG content in control, IL-1β and celecoxib treated cultures with corresponding histological staining correlating with these results. Additionally, gene expression showed an upregulation in COL1A1, COL2A1 and ACAN and a downregulation in MMP13 and ADAMTS5 under physioxia for all experimental groups. Physioxia alone had a stronger effect in countering the inhibitory effects of IL-1β treated meniscus cells than celecoxib under hyperoxia. Preconditioning meniscus cells under physioxia prior to implantation has the potential to improve clinical outcomes for cell-based therapies of the meniscus

Abstract. Objective. Meta-analysis of clinical trials highlights that non-operative management of degenerative knee meniscal tears is as effective as surgical management. Surgical guidelines though support arthroscopic partial meniscectomy which remains common in NHS practice. Physiotherapists are playing an increasing role in triage of such patients though it is unclear how this influences clinical management and patient outcomes. Methods. A 1-year cohort (July 2019–June 2020) of patients presenting with MRI confirmed degenerative meniscal tears to a regional orthopaedic referral centre (3× ESP physiotherapists) was identified. Initial clinical management was obtained from medical records alongside subsequent secondary care management and routinely collected outcome scores in the following 2-years. Management options included referral for surgery, conservative (steroid injection and rehabilitation), and no active treatment. Outcome scores collected at 1- and 2-years included the Forgotten Joint Score-12 (FJS-12) questionnaire and 0–10 numerical rating scales for worst and average pain. Treatment allocation is presented as absolute and proportional figures. Change in outcomes across the cohort was evaluated with repeated measures ANOVA, with Bonferroni correction for multiple testing, and post-hoc Tukey pair-wise comparisons. As treatment decision is discrete, no direct contrast is made between outcomes of differing interventions but additional explorative outcome change over time evaluated by group. Significance was accepted at p=0.05 and effect size as per Cohen's values. Results. 81 patients, 50 (61.7%) male, mean age 46.5 years (SD13.13) presented in the study timeframe. 32 (40.3%) received conservative management and 49 (59.7%) were listed for surgery. Six (18.8%) of the 32 underwent subsequent surgery and nine of the 49 (18.4%) patients switched from planned surgery to receiving non-operative care. Two post-operative complications were noted, one cerebrovascular accident and one deep vein thrombosis. The cohort improved over the course of 2-years in all outcome measures with improved mean FJS-12 (34.36 points), mean worst pain (3.74 points) average pain (2.42 points) scores. Overall change (all patients) was statistically significant for all outcomes (p<0.001), with sequential year-on-year change also significant (p<0.001). Effect size of these changes were large with all Cohen-d values over 1. Controlling for age and BMI, males reported superior change in FJS-12 (p=0.04) but worse pain outcomes (p<0.03). Further explorative analysis highlighted positive outcomes across all surgical, conservative and no active treatment groups (p<0.05). The 15 (18%) patients that switched between surgical and non-surgical management also reported positive outcome scores (p<0.05). Conclusion(s). In a regional specialist physiotherapy-led soft tissue knee clinic around 60% of degenerative meniscal tears assessed were referred for surgery. Over 2-years, surgical, non-operative and no treatment management approaches in this cohort all resulted in clinical improvement suggesting that no single strategy is effective in directly treating the meniscal pathology, and that perhaps none do. Clinical intervention rather is directed at individual symptom management based on clinical preferences. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction and Objective. The meniscus is composed of two distinct regions, a vascular outer zone and an avascular inner zone. Due to vascularization, tears within the vascular zone can be treated by suturing. However, tears in the avascular zone have a poor healing capacity and partial meniscectomy is used to prevent further pain, although this leads to early osteoarthritis. Previous studies have demonstrated that the vascular zone contains a progenitor population with multilineage differentiation potential. Isolation and propagation of these progenitors can be used to develop cell-based therapies for treating meniscal defects. In vivo, the meniscus resides under a low oxygen environment, also known as physioxia (2–7% oxygen) and previous work suggests that it promotes the meniscal phenotype. The objective of the study was to isolate progenitor populations from both meniscus regions and to examine their clonogenecity and differentiation potential under both hyperoxia (20% oxygen) and physioxia (2% oxygen). We hypothesize that physioxia will have a beneficial effect on colony formation and trilineage differentiation of meniscal cells. Materials and Methods. Human meniscus (n =4; mean age: 64 + 6) tissue was split into vascular and avascular regions, finely cut into small pieces and then sequentially digested in pronase (70U/mL) and collagenase (200U/mL) at 37. 0. C. Avascular and vascular meniscus cells were counted and split equally for expansion under hyperoxia and physioxia at a seeding density of 5 × 10. 3. cells/cm. 2. At passage 1, cells were seeded at 2, 5 and 20 cells/cm. 2. in 10cm dishes for observing colony formation using crystal violet assay. At passage 3, vascular and avascular meniscus cells were differentiated towards the chondrogenic, osteogenic and adipogenic lineage. Chondrogenesis was evaluated using DMMB staining for GAG deposition, osteogenesis was assessed using Alizarin Red staining for calcium deposition, whilst adipogenesis was observed using Oil-Red-O staining for fat droplets. Results. Expansion of vascular and avascular meniscus cells showed no difference in doubling time between hyperoxic or physioxic culture. However, physioxia significantly increased the number of colonies compared to hyperoxia for both meniscus cell types (p < 0.05). Both vascular and avascular meniscus cells differentiated towards the chondrogenic, osteogenic and adipogenic lineage under both oxygen tensions. Interestingly, we observed greater DMMB, alizarin red and oil-red-o staining for vascular meniscal cells under physioxia compared to corresponding hyperoxic cultures and avascular meniscal cells. Conclusions. Physioxia enhances the clonogenecity of vascular and avascular meniscus cells. Trilineage differentiation potential was observed from both regions with increased capacity detected under physioxia for vascular meniscal cells. Physioxic isolation of meniscal cells for the propagation of these progenitors can used be for the treatment of meniscal tears/defects

For the treatment of irreparable meniscal injuries, we developed a novel multilayer meniscal scaffold, consisting of collagen, strontium and cellulose derived from Luffa Cylindirica; and we evaluated its effects on meniscal regeneration and arthritic changes in a rabbit partial meniscectomy model. The meniscus has a key role in shock absorbtion, load distribution, chondroprotection and stability of the knee joint. Meniscal injuries are one of the most common orthopedic injuries and may lead to degenerative cartilage changes and eventually osteoarthritis. Repair of the meniscal tissue is the treatment of choice for patients with a meniscus lesion, however, this is not always possible, especially for degenerative tears or injuries located on the inner avascular zone. To overcome the devastating outcomes of meniscectomy for such injuries, several materials have been developed and tried to replace the resected meniscal tissue. These scaffolds were designed primarily to relieve pain after meniscectomy, and later on were aimed to prevent osteoarthritis and cartilage damage that may develop in the future. In the quest for optimum scaffold material small intestine, tendons and other isolated tissues, collagen and polyurethane have been researched. Nevertheless, none of these materials have absolutely proven satisfying identical replacement of resected meniscal tissue. Therefore, we developed and investigated a novel multilayer meniscal scaffold, consisting of collagen, strontium and cellulose derived from Luffa Cylindirica (a cucumber shaped and sized plant, known as sponge gourd). The aim of the study was to evaluate the meniscal regeneration and arthritic changes after partial meniscectomy and application of novel multilayer meniscal scaffold in a rabbit model and to compare the results with clinically used polyurethane scaffold (Actifit, Orteq Ltd, London, UK). Sixteen male, mature, NewZealand rabbits weighing between 2600–3500 g were randomly divided into three groups. All groups underwent knee surgery via a medial parapatellar approach and a reproducible 1.5-mm cylindrical defect was created in the avascular zone of the anterior horn of the medial meniscus bilaterally. Defects were filled with the polyurethane scaffold in Group 1 and novel multilayer scaffold was applied to fill the defects in Group 2(n:6). Four rabbits in Group 3 did not receive any treatment and defects were left empty. Animals were sacrified after 8 weeks and bilateral knee joints were taken for macroscopic, biomechanical, and histological analysis. No signs of inflammation or infection were observed in all animals. Macroscopic evaluation of tibial plateaus after excision of menisci was performed with digital images of inked condylar surfaces. No significant degenerative changes were detected between groups. Digital photographs of excised menisci were also obtained and surface areas were measured by a computer software (Image J version 1.46, National Institute of Health, Bethesda, MD). There was a slightly larger meniscus area in the first two groups than the no treatment group, however, this was not found significant. Indentation testing of the tibial condyle and compression tests for the relevant meniscal areas with a diameter of 3mm was also performed in all groups. Histological analysis was made and all specimens were stained with safranin O and scored according to a scoring system. In this study, the initial evaluation of novel multilayer meniscal scaffold demonstrated promising biomechanical and histological results; besides no adverse events related to scaffold material was observed

Objectives

Meniscal injuries are often associated with an active lifestyle. The damage of meniscal tissue puts young patients at higher risk of undergoing meniscal surgery and, therefore, at higher risk of osteoarthritis. In this study, we undertook proof-of-concept research to develop a cellularized human meniscus by using 3D bioprinting technology.

We hypothesised that meniscal tears treated with mesenchymal stem cells (MSCs) together with a conventional suturing technique would show improved healing compared with those treated by a conventional suturing technique alone. In a controlled laboratory study 28 adult pigs (56 knees) underwent meniscal procedures after the creation of a radial incision to represent a tear. Group 1 (n = 9) had a radial meniscal tear which was left untreated. In group 2 (n = 19) the incision was repaired with sutures and fibrin glue and in group 3, the experimental group (n = 28), treatment was by MSCs, suturing and fibrin glue.

At eight weeks, macroscopic examination of group 1 showed no healing in any specimens. In group 2 no healing was found in 12 specimens and incomplete healing in seven. The experimental group 3 had 21 specimens with complete healing, five with incomplete healing and two with no healing. Between the experimental group and each of the control groups this difference was significant (p < 0.001).

The histological and macroscopic findings showed that the repair of meniscal tears in the avascular zone was significantly improved with MSCs, but that the mechanical properties of the healed menisci remained reduced.