Shedding light on the effects of blood on meniscus tissue: the role of mononuclear leukocytes in mediating meniscus catabolism.

OBJECTIVE: Traumatic meniscal injuries can cause acute pain, hemarthrosis (bleeding into the joint), joint immobility, and post-traumatic osteoarthritis (PTOA). However, the exact mechanism(s) by which PTOA develops following meniscal injuries is unknown. Since meniscus tears commonly coincide with hemarthrosis, investigating the direct effects of blood and its constituents on meniscus tissue is warranted. The goal of this study was to determine the direct effects of blood and blood components on meniscus tissue catabolism. METHODS: Porcine meniscus explants or primary meniscus cells were exposed to whole blood or various fractions of blood for 3 days to simulate blood exposure following injury. Explants were then washed and cultured for an additional 3 days prior to collection for biochemical analyses. RESULTS: Whole blood increased matrix metalloproteinase (MMP) activity. Fractionation experiments revealed blood-derived red blood cells did not affect meniscus catabolism. Conversely, viable mononuclear leukocytes induced MMP activity, nitric oxide (NO) production, and loss of tissue sulfated glycosaminoglycan (sGAG) content, suggesting that these cells are mediating meniscus catabolism. CONCLUSIONS: These findings highlight the potential challenges of meniscus healing in the presence of hemarthrosis and the need for further research to elucidate the in vivo effects of blood and blood-derived mononuclear leukocytes due to both hemarthrosis and blood-derived therapeutics.

Low meniscus reoperation rates following meniscus repair during anterior cruciate ligament reconstruction in Turkey: an in-depth national analysis of 8-years.

BACKGROUND: Concomitant knee injuries, such as meniscal tears, are observed in up to 80% of cases and can have a detrimental impact on outcomes following anterior cruciate ligament reconstruction (ACLR). Over recent decades, there has been a growing recognition of the importance of preserving meniscal tissue. Consequently, the prevalence of meniscal-preserving procedures has been on the rise. PURPOSE: The objective of this study was to examine the prevalence of concurrent meniscal procedures, assess the success rate, and identify factors associated with the failure of meniscal repair in patients undergoing ACLR. METHODS: All patients who underwent ACLR due to anterior cruciate ligament (ACL) injury between January 2015 and December 2022 were extracted from the Republic of Türkiye National health system using operation-specific procedure codes. Patients with multiple ligament injuries, revision ACL patients, and patients with missing data were excluded from the study. The treatment methods were grouped into the subsets of meniscectomy, meniscal repair, transplantation, and meniscectomy + repair. The distribution of ACLR and meniscus treatment methods according to years, age and sex groups, hospital characteristics, and geographical regions was examined. A secondary analysis was performed to assess the effect of patient demographics and hospital healthcare level on revision meniscal procedures in the ACLR + concomitant meniscal repair group. RESULTS: A total of 91,700 patients who underwent ACLR between 2015 and 2022 were included in the study. A concomitant meniscal procedure was noted in 19,951(21.8%) patients (16,130 repair,3543 meniscectomy). In the 8 years studied, meniscus repair rates increased from 76.3%to87.9%, while meniscectomy rates decreased from 23.7%to12.1% (p < 0.001). The revision meniscus surgery rate following ACLR + meniscal repair was 3.7%at a mean follow-up of 50 ± 26 months. The interval between primary and revision surgery was 20.5 ± 21.2 months. The meniscectomy rates were higher in community hospitals, while private hospitals showed the lowest revision meniscus surgery rates. Younger age was associated with increased meniscus repair failure rates. CONCLUSION: The propensity towards using repair techniques to treat meniscal tears during concurrent ACLR has significantly increased in Turkey. Age and the healthcare level of the treating hospital affect the success of meniscal repair.

Rate of meniscal repair versus meniscectomy has improved, and should continue to improve.

As a result of research supporting meniscus preservation, evidence shows that internationally, there has been a rise in rates of meniscus repair, especially in younger population, and a decline in rates of partial meniscectomy. The decline in partial meniscectomy has been rather rapid and has outpaced the rise in meniscal repair, likely due to increasing evidence against routine partial meniscectomy in degenerative tears with coexistent arthritis. However, despite the rise in meniscus repair, close to 95% meniscus surgeries are still partial meniscectomies. Partial meniscectomy to meniscus repair ratio seems to be rather high. Optimistically, this will improve because successful repair outcomes have been demonstrated in situations previously considered "high-risk," including complex patterns, central tears, radial tears, and root and ramp tears. This may be due to multiple factors, many of which may be beyond the control of surgeons, including the fact that as many as 25% of repairs fail to heal. Yet, with improved techniques and instrumentation, the success rate of repair is improving. Cost of repair may be a limiting factor, especially in low-income countries with poor health insurance penetration and unfavorable reimbursement of repair cost. Every effort must be made to repair a tear which has potential to heal.

Females show worse functional outcome and quality of life compared to males 2 years after meniscus surgery: Data analysis from the German Arthroscopy Registry.

PURPOSE: The purpose of this study was to investigate the impact of sex on knee function, activity and quality of life following meniscus surgery using data from the German Arthroscopy Registry. METHODS: This is a retrospective cohort study with data collected between 2017 and 2022. Patient-reported outcome measures (PROMs), namely Knee Injury and Osteoarthritis Outcome Score (KOOS), EuroQol Visual Analogue Scale (EQ Scale), and Marx Activity Rating Scale (MARS), were collected preoperatively and at 6, 12 and 24 months postoperatively. Data were analysed to examine differences between male and female patients regarding PROMs, pre-existing conditions, meniscus lesion types and surgical treatments. RESULTS: A total of 1106 female (36.6%) and 1945 male patients (63.7%) were included. Males were significantly younger than females and had a higher body mass index. Overall, there were four times more medial meniscus lesions (MMLs) (77.5%) than lateral meniscus lesions (LMLs) (27.9%). Degenerative LMLs were more frequent in females, while traumatic LMLs were more common in males. Frequencies of traumatic and degenerative MMLs were similar among males and females. Males had higher absolute KOOS irrespective of treatment or meniscus lesion type. Meniscus repair resulted in similar improvements in ΔKOOS for both sexes, while meniscus resection exhibited higher absolute KOOS for males at each time point. Males generally had higher EQ Scale and MARS than females. CONCLUSION: Greater improvements in knee function, activity and quality of life were observed in males. While MMLs appear to be comparable among sexes, the nature of LML differed significantly. These results may help surgeons to refine patient selection for specific treatments to improve overall clinical outcomes. LEVEL OF EVIDENCE: Level III.

Failure rate of isolated medial meniscus repair in the stable knee: Systematic review and meta-analysis.

PURPOSE: The present meta-analysis aims to determine the outcomes and failure rates for medial meniscus repairs in patients with stable knees. METHODS: A literature search was conducted using PubMed and Scopus with the terms '(medial meniscus OR medial meniscal) AND (repair)'. The search strategy was based on the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) protocol and included 93 articles assessed for eligibility. The search criteria were limited to studies reporting outcomes and failure rates. The exclusion criteria included languages other than English, biomechanical studies, letters to editors, non-full text, review articles, meta-analyses and case reports. RESULTS: In total, 10 studies with 595 patients were included. Degenerative tears or studies reporting meniscus repair outcomes on root repairs, revision or primary anterior cruciate ligament reconstruction, discoid menisci or ramp lesions were excluded. All studies included revision surgery and/or clinical symptoms as failure definitions. The overall medial meniscal repair failure rate was 26% with a 95% confidence interval (CI) [15%-37%]. The mean time to failure from isolated medial meniscus repair surgery was 27.7 months with 95% CI [18.5-36.9 months]. The postoperative Lysholm and IKDC scores were reported in three articles. At the final follow-up, the mean postoperative Lysholm and IKDC scores were 92.3 with 95% CI [84.5-100] and 88.6 with 95% CI [83.5-93.8], respectively. CONCLUSION: The current meta-analysis revealed an overall failure rate of 26% in the case of medial meniscus repair in a stable knee. For these reasons, the patient should be aware of the substantial risk of revision surgery (one out of four cases). Medial meniscus repair in a stable knee yielded good clinical results. LEVEL OF EVIDENCE: II.

Segond fracture: an indicator for increased risk of lateral meniscus injury in patients with acute anterior cruciate ligament ruptures.

PURPOSE: The purpose of this study was to investigate the incidence and anatomic distribution of meniscus injury in patients who have sustained acute ACL injuries with and without concomitant Segond fracture. We hypothesized that patients who have sustained a torn ACL with a concomitant Segond fracture would have a higher incidence of lateral meniscal injuries than patients with an isolated ACL injury. METHODS: Patients who underwent ACL reconstruction from 2012 to 2022 were retrospectively reviewed. Segond fractures were identified on knee radiographs. Inclusion criteria were age 18-40, injury during sports activity, and reconstruction within 90 days of injury. Sports activity, anatomic location of meniscus injury, and meniscus treatment were documented. Multivariable regression was used to identify predictors of meniscus injury/treatment. RESULTS: There were 25 of 603 (4.1%) patients who had an ACL tear with concomitant Segond fracture. The incidence of lateral meniscus injury in the Segond group (72%) was significantly higher than in the non-Segond cohort (49%; p = 0.024). A significantly smaller proportion of medial meniscus injuries among patients with Segond fractures were repaired (23.1%) compared to the non-Segond group (54.2%; p = 0.043). Multivariate analysis found patients with Segond fractures to have increased odds of lateral meniscus injury (OR 2.68; [1.09, 6.60], p = 0.032) and were less likely to have medial meniscus injuries repaired (OR 0.35; [0.15, 0.81], p = 0.014). Additionally, males had increased odds of lateral meniscus injury (OR 1.54; [1.08 - 2.91], p = 0.017), which were more likely to require repair (OR 1.48; [1.02, 2.14], p = 0.038). CONCLUSIONS: Among acute ACL injuries, the incidence of lateral meniscus injury is greater among patients with Segond fractures. Patients with Segond fracture were less likely to undergo repair of medial meniscal injuries.

Patients with discoid menisci have similar clinical outcomes to those without discoid menisci when undergoing surgical intervention: a systematic review.

PURPOSE: To compare post-operative clinical outcomes of discoid meniscus tear procedures such as saucerization with or without repair with those of non-discoid meniscus tears such as meniscectomy or repair in skeletally mature patients with no concomitant injuries. METHODS: Three databases MEDLINE, PubMed and EMBASE were searched from inception to July 3rd, 2022 for literature describing patient-reported outcome measures after meniscus surgery in discoid or non-discoid meniscus tears. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Clinical outcome data on Lysholm, Tegner, International Knee Documentation Committee (IKDC), revision rates, and complications were recorded, with MINORS and Detsky scores used for quality assessment. RESULTS: A total of 38 studies comprising 2213 patients were included with a mean age of 38.6 years (range: 9.0-64.4). The mean follow-up time was 54.1 months (range: 1-234) and the average percentage of female participants was 46.8% (range: 9.5-95.5). The mean change between pre-operative and post-operative Lysholm scores ranged from 21.0-39.0, 7.4-24.1, and 24.2-48.4 in the discoid, non-discoid meniscectomy, and non-discoid repair groups, respectively. The mean change in Tegner scores ranged from 0.0 to 2.3, 1.3, and 0.4-1.3 in the discoid, non-discoid meniscectomy, and non-discoid repair groups, respectively. Pre-operative IKDC scores were not reported, however mean post-operative IKDC scores ranged from 77.4 to 96.0, 46.9 to 85.7, and 63.1 to 94.0 in discoid, non-discoid meniscectomy, and non-discoid repair groups, respectively. Revision rates for discoid procedures, non-discoid meniscectomies, and non-discoid meniscus repairs ranged from 3.2 to 44.0%, 8.3 to 56.0%, and 5.9 to 28.0%, respectively. The most common reasons for revision were acute trauma and persistent pain. CONCLUSION: Discoid saucerization procedures with or without repair leads to similar Lysholm scores as non-discoid repair procedures, and similar IKDC scores and revision rates compared to non-discoid meniscectomy or repair procedures. Patients undergoing discoid procedures appeared to have slightly higher Tegner activity scores compared to patients undergoing non-discoid procedures; however this is to be considered in the context of a younger population of patients undergoing discoid procedures than non-discoid procedures. This information can help guide surgeons in the decision-making process when treating patients with discoid menisci, and should guide further investigations on this topic. LEVEL OF EVIDENCE: IV.

Low early complication rates after arthroscopic meniscus repair and meniscectomy.

PURPOSE: To evaluate the 30-day complication rates after arthroscopic meniscus repair and meniscectomy using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, with subgroup analysis of patients aged > 40 years. METHODS: NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing arthroscopic meniscus repair (CPT 29882, 29883) and meniscectomy (29880, 29881). The following 30-day complications were assessed: pulmonary embolism (PE), venous thromboembolism (VTE), surgical site infection (SSI), reoperation, and readmission. Complications rates between treatment groups were compared using multivariate logistic regression analyses adjusted for sex, age, steroid use, and smoking/dyspnoea/COPD. A subgroup analysis was performed for patients aged > 40 years. RESULTS: A total 6354 meniscus repairs and 99,372 meniscectomies were identified. Complication rates were < 1% for both meniscus repair and meniscectomy. Meniscus repair was associated with significantly higher rates of PE, VTE, and readmission compared to meniscectomy: PE (0.2% vs 0.1%, p < 0.001), VTE (0.8% vs 0.4%, p < 0.001), superficial SSI (0.1% vs 0.2%, n.s), deep SSI (0.07% vs 0.1%, n.s), reoperation (0.5% vs 0.4%, n.s), and readmission (0.9% vs 0.8%, p = 0.003). Among patients aged > 40 years, complication rates were < 1.3% for both meniscus repair and meniscectomy. Similar trends and rates were found in patients aged > 40 years undergoing meniscus repair versus meniscectomy: PE (0.38% vs 0.12%, p < 0.001), VTE (1.07% vs 0.46%, p < 0.001), superficial SSI (0.03% vs 0.19%, n.s), deep SSI (0.1% vs 0.06%, n.s), reoperation (0.48% vs 0.43%, n.s), and readmission (1.2% vs 0.85%, p = 0.01). CONCLUSION: Arthroscopic meniscus repair and meniscectomy are both low-risk procedures with 30-day complication rates < 1% overall and < 1.3% among patients aged > 40 years. These findings support meniscus repair whenever feasible in the setting of preserved articular cartilage. Understanding of the short-term complication rates after arthroscopic meniscus repair and meniscectomy can aid surgeons in providing comprehensive preoperative counselling to patients considering such treatments, specifically when discussing the risks and benefits of meniscus repair. LEVEL OF EVIDENCE: III.

Management after acute injury of the anterior cruciate ligament (ACL), part 2: management of the ACL-injured patient.

PURPOSE: The aim of this consensus project was to create a treatment algorithm for the management of the ACL-injured patient which can serve as an aid in a shared decision-making process. METHODS: For this consensus process, a steering and a rating group were formed. In an initial face-to-face meeting, the steering group, together with the expert group, formed various key topic complexes for which various questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement. RESULTS: During this consensus process, 15 key questions were identified. The literature search for each key question resulted in 24 final statements. Of these 24 final statements, all achieved consensus. CONCLUSIONS: This consensus process has shown that ACL rupture is a complex injury, and the outcome depends to a large extent on the frequently concomitant injuries (meniscus and/or cartilage damage). These additional injuries as well as various patient-specific factors should play a role in the treatment decision. The present treatment algorithm represents a decision aid within the framework of a shared decision-making process for the ACL-injured patient. LEVEL OF EVIDENCE: Level V.

Low reoperation rate following lateral meniscus root repair: clinical outcomes at 2 years follow-up.

PURPOSE: The aim of this study was to review the outcomes of lateral meniscus posterior root tears repair at the time of ACL reconstruction at a minimum 2-year follow-up. METHODS: Between March 2015 and August 2018, 2017 patients underwent primary ACL reconstruction and were considered for study eligibility. Lateral meniscus posterior root tears were identified arthroscopically, and repair was performed with a transtibial pull-out suture technique or a side-to-side suture technique. Clinical outcomes were recorded at the time of physical examination. At the end of the study period, patients were contacted to determine whether they had required reoperation. RESULTS: Lateral meniscus posterior root tears were identified in 153 out of the 2,017 primary ACL reconstructions (7.6%). Ninety-nine patients were included for analysis: 23 transtibial pull-out sutures and 76 side-to-side repairs. At a mean follow-up of 42 ± 10 months, one patient (1%) had undergone reoperation for failure of the side-to-side repair. There were 11 reoperations in 10 patients (10.1%), including 6 cyclops syndrome, 1 graft rupture, 1 tibial bone cyst, 1 medial and 1 lateral meniscus repair failure, and 1 arthrolysis. Postoperatively, ninety (90.9%) patients were graded A for the IKDC objective score and 9 (9.1%) patients were graded B, with an IKDC subjective score of 86.9 ± 7.6, a Lysholm score of 90.7 ± 6.7 and a median Tegner Activity Scale of 6 (3-9). All of their objective and subjective evaluations improved after surgery (p < 0.001) except for the Tegner Activity Scale. Ten patients underwent second look arthroscopy (10.1%), lateral meniscus healing was observed in 9 out of 10 patients (90%). CONCLUSION: This study demonstrated that lateral meniscus posterior root tear repair is a safe procedure with a very low reoperation rate at a minimum follow-up of 2 years. LEVEL OF EVIDENCE: IV.

Arthroscopic repair of degenerative medial meniscus tears in patients aged over 45 years resulted in favorable clinical outcomes and low clinical failure rates at a minimum 2-year follow-up.

PURPOSE: This study aimed to investigate clinical and radiological results of arthroscopic repair for isolated medial degenerative meniscus tears (DMTs) in patients over 45 years old at a minimum 2-year follow-up. METHODS: From 2013 to 2017, patients aged over 45 years with isolated medial DMT refractory to conservative management or with true mechanical symptoms who had undergone arthroscopic repair were retrospectively reviewed. Arthroscopic meniscus repair was performed using all-inside or all-inside and inside-out technique in combination with bone marrow venting procedure. Tear patterns were classified according to arthroscopic findings. Magnetic resonance imaging (MRI) and outcome evaluations, including Lysholm score, Tegner activity score, and International Knee Documentation Committee (IKDC) score, were evaluated preoperatively and at the final follow-up. International Cartilage Repair Society grades of the medial compartments and MRI signal at tear sites were assessed preoperatively and at the final follow-up. A grade 0 to 2 signal at the repair site suggested a healed meniscus, whereas a grade 3 signal suggested an unhealed meniscus. Clinical failure was determined according to Barrett criteria. RESULTS: Twenty-seven patients (mean age, 57.7 ± 7.4 years) were enrolled. The mean follow-up was 52.0 ± 15.6 months. Among tear patterns, 48% were complex tears, 30% were horizontal tears, and 22% were other patterns. The mean Lysholm score and IKDC score significantly improved from 53 ± 25 to 89 ± 15 (p < 0.001) and 34 ± 24 to 72 ± 15 (p < 0.001) at the final follow-up, respectively. The median Tegner activity score significantly improved from 1 (range 1-4) to 4 (range 2-7, p < 0.001). Three (11%) patients were considered clinical failures, and five patients (19%) had cartilage lesion progression. At the final follow-up, MRI showed grade 0 in one (4%) patient, grade 1 in nine (33%) patients, grade 2 in six (22%) patients, and grade 3 in eleven (41%) patients. CONCLUSION: Arthroscopic repair of isolated medial DMT refractory to conservative management or with true mechanical symptoms in patients aged over 45 years had good to excellent clinical outcomes with low clinical failure rates, despite unhealed menisci being observed on MRI in 41% of patients at a mean 4.3-year follow-up. Arthroscopic repair could be a treatment option for these patients. LEVEL OF EVIDENCE: IV.

Incidence and type of meniscal tears in multilligament injured knees.

PURPOSE: Meniscal injuries occurring during multi-ligament knee injuries (MLKI) are underreported. The purpose of this study was to compare the incidence and type of meniscal tears seen at the time of multi-ligament reconstruction surgery compared to those occurring during isolated anterior cruciate ligament (ACL) surgery. METHODS: Patients undergoing surgical treatment for MLKI and ACL-only injuries between 2010 and 2020 were reviewed. Two-hundred and thirty-five patients were included in the MLKI group. There were 131 chronic injuries and 104 acute injuries. Two-hundred and twenty-two ACL-only chronic injuries were used as a control group for comparison with the chronic MLKI group. Demographic data, type of meniscal tears, ligament injury patterns (Schenck classification) and time from injury to surgery were recorded. A delayed procedure was defined by a 4-week interval after the knee injury. RESULTS: A meniscus was torn in 69 knees (29.4%): 36 knees (15.3%) with an isolated medial meniscus tear, 33 knees (17.9%) with an isolated lateral meniscus tear,.Nine knees (3.8%) had both menisci torn. MLKI with medial or lateral-sided bicruciate ligament injuries (KDIIIM-KDIIIL) were significantly associated with a lower rate of meniscal tears than knee injuries involving the ACL-only and medial/lateral-sided ligament injuries (KDI) (medial-sided injuries p = 0.025; lateral-sided injuries p = 0.049). Lateral-sided injuries had significantly less meniscal damage than medial-sided injuries: 22/124 (17.7%) vs. 41/100 (41%); (p < 0.001). No significant differences were found for frequency, type and distribution of meniscal tears between acute and chronic MLKI surgery. ACL-only chronic injuries were associated with a higher rate of meniscal tears: 123/222 knees (55.4%) vs. 35/131 (26.9%) chronic MLKI; (p < 0.001), mainly involving the medial meniscus: 102/222 (46%) vs. 18/131 (13.7%); (p < 0.001). CONCLUSIONS: Meniscal tears were less common in the MLKI group than in the isolated ACL injury group. The degree of ligament injury patterns and the side of the injured collateral ligament influenced the type and incidence of meniscal damage. Contrary to isolated ACL injuries, a delayed procedure was not associated with a higher rate of meniscal lesions but did influence the type of treatment. Understanding of meniscal tears patterns in MLKI helps to improve the treatment management of these complex injuries.

Meniscus repair via collagen matrix wrapping and bone marrow injection: clinical and biomolecular study.

PURPOSE: The functional outcomes of arthroscopic matrix-based meniscus repair (AMMR) in patients two and five years after the treatment clearly show that the use of the collagen matrix and bone marrow aspirate creates favorable biological conditions for meniscus healing. This study not only provides ten follow-up results but also investigates biomolecular mechanisms governing the regenerative process. METHODS: Case series was based on data collected from patients who underwent AMMR procedure, starting with preoperatively through two-year and five-year till ten-year follow-up. The outcomes are presented as IKDC and the Lysholm subjective scores as well as the imaging results. Biomolecular investigation of the membranes utilized in the AMMR procedure include DNA content analysis, cell viability and proliferation study of bone marrow and bone marrow concentrate-derived cells, and cytokine array performed on monocytes cultured on the membranes. CONCLUSION: Data collected from patients who underwent AMMR procedure, starting with pre-operatively through two year and five year till ten year follow-up, indicate the possibility for long-term, stable meniscus preservation. Outcomes are manifested with a visible improvement of the IKDC and the Lysholm subjective scores as well as in the imaging results. The type of the meniscal tear or complexity of the knee injury (isolated AMMR vs. AMMR + ACL) did not affect the clinical outcomes. The study highlighted the role of the membrane in facilitating cell adhesion and proliferation. Additionally, several cytokines were selected as potentially crucial products of the membrane vs. monocyte interactions, driving the tissue regeneration and remodeling. Interestingly, thresholds of what constitutes a safe and well-decellularized membrane according to relevant literature have been significantly breached, but ultimately did not elicit detrimental side effects.

Coronal extrusion of the lateral meniscus does not increase after pullout repair of the posterior root of the lateral meniscus at short-term follow-up.

PURPOSE: Posterior lateral meniscus root (PLMR) tears are injuries that commonly occur together with anterior cruciate ligament (ACL) tears. The aim of this study was to evaluate the clinical and radiological outcome of PLMR repair accompanying ACL reconstruction. Specifically, PLMR healing rates, meniscal extrusion behavior and their influence on patient-reported outcome measures (PROMs) were analyzed. It was hypothesized that PLMR repair shows satisfactory healing rates and coronal meniscal extrusion does not increase significantly following PLMR repair. METHODS: Patients that underwent PLMR repair between 2014 and 2019 were evaluated at least 12 months postoperatively. At follow-up, magnetic resonance imaging (MRI) was performed in order to evaluate the PLMR healing behavior (complete vs. partial vs. no healing) as well as the coronal and sagittal meniscal extrusion in comparison with the preoperative MRI. Additionally, patient-reported outcome measures (PROMs; Lysholm score, International Knee Documentation Committee subjective knee form [IKDC]) were compiled. Pre- and postoperative meniscal extrusion were tested for statistical significance using the paired t test. The Kruskal-Wallis test was used to compare extrusion values and PROMs in relation to different healing states. A correlation analysis was conducted using the Pearson correlation coefficient between differences in meniscal extrusion and PROMs. RESULTS: Out of 25 patients, 18 patients (72.0%; 11 male and seven female) were available for final assessment at a mean follow-up of 40.8 ± SD 17.5 months. One revision PLMR repair was performed five months after the initial repair. In 14 cases (77.8%), healing of the lateral meniscus was observed (6 × complete, 8 × partial). Coronal extrusion of the lateral meniscus did not increase significantly following PLMR repair (2.0 ± 1.5 mm vs. 2.1 ± 1.3 mm; p = 0.645). Sagittal extrusion increased significantly (25.7 ± 2.4 mm vs. 27.0 ± 1.4 mm; p < 0.001). The healing status of the PLMR showed no significant association with meniscal extrusion or PROMs (p > 0.05). But a higher increase in coronal meniscal extrusion negatively affected PROMs (Lysholm score: p = 0.046, r = - 0.475; IKDC: p = 0.003, r = - 0.651). CONCLUSION: High healing rates of the PLMR and no significant increase in coronal extrusion may be expected following combined PLMR repair and ACL reconstruction. But a greater increase in postoperative coronal meniscal extrusion correlates with less favorable clinical results. A greater increase in sagittal extrusion was observed, but this did not influence the clinical outcome. LEVEL OF EVIDENCE: Retrospective Case Series; IV.

True all inside meniscus repair using the popliteus tendon.

The popliteus tendon is a useful anchor point to repair the posterior horn of the lateral meniscus. We describe a new, economical technique that does not violate the neurovascular structures, using an antegrade suture passer and a 2-0 fiberwire to repair the posterior segment including posterior horn of the lateral meniscus taking bites through the capsule and meniscus or the popliteus tendon and meniscus with no anchors in the capsule or popliteus. 9 patients were operated upon using this technique and the mean IKDC score improved from 24.2 to 84, p < 0.01, mean pre op Tegner improved from 1.88 to 6.63 p < 0.01, median hop test from 0 to 4, p = 0 at a mean 15.2 months post surgery. 8 patients had a negative Lachman and 1 grade 2 Lachman at 12 months follow up but was asymptomatic. The Barret's criteria was negative for all 9 patients at latest follow up.

[Concerns of Technical Evaluation on Registration of All-inside Meniscus Suture System].

OBJECTIVE: To summarize the product registration declaration ideas and registration technical review of the all-inside meniscal suture system, and to systematically think about of the technical review concerns of the all-inside meniscal suture system products to provide technical guidance for improving the quality of registration and application and regulatory efficiency. METHODS: Consult the public information of such products at home and abroad, and summarize the experience of registration review of such products. RESULTS: The technical review of the all-inside meniscus suture system registration mainly focuses on product basic information, pre-clinical research, clinical evaluation and product technical requirements. CONCLUSIONS: The difficulty of product registration and declaration of the all-inside meniscus suture system lies in the provision of pre-clinical research data of the product, and the applicant needs to strengthen the basic research ability, formulate scientific technical indicators and test methods to ensure the safety and effectiveness of the product, and also provide sufficient supporting data for the registration declaration.

Clinical outcome and healing rate after meniscal bucket handle tear repair.

BACKGROUND: Reports combining patient-reported outcome measures, clinical evaluation, and radiographic assessment of postoperative healing after arthroscopic repair of bucket-handle meniscal tears (BHMT) are scarce. METHODS: Patients who underwent arthroscopic repair for acute traumatic BHMTs between October 2011 and March 2016 with a minimum follow-up of two years were included. Postoperative outcome scores comprised the International Knee Documentation Society Score (IKDC), Lysholm score, Tegner activity score (TAS), and visual analog scale (VAS) for pain. Clinical meniscal healing failure was assessed according to Barrett's criteria. Side-to-side difference in knee laxity was measured using KT-2000. Radiographic healing was assessed by 3-Tesla magnetic resonance imaging (MRI) and classified according to Henning's criteria at final follow-up. RESULTS: Forty patients with a mean age of 32.0 ± 11.5 years were available for follow-up after 51.8 ± 14.3 months. Revision surgery by means of arthroscopic partial meniscectomy was performed in four patients (10%) prior to the follow-up visit. The clinical healing rate was 83.3% at final follow-up. Mean IKDC score was 82.8 ± 13.8 and Lysholm score was 77.4 ± 24.8. Of all patients, 87.5% reached or exceeded the patient-acceptable symptomatic state (PASS) criteria for the IKDC score at final follow-up. The median TAS was 6 and VAS for pain was 0.46 ± 0.9. Side-to-side difference in knee laxity was higher in patients with concomitant ACL reconstruction (2.1 ± 2.7 mm) compared to isolated BHMTs (1.0 ± 2.0 mm). MR examination showed 69.4% healed, 25.0% partially healed, and 5.6% unhealed menisci. CONCLUSION: Patients who underwent repair for acute traumatic BHMTs achieved good to excellent clinical outcome along with a high rate of meniscal healing at a minimum follow-up of two years. Clinical and radiological healing rates were similarly satisfactory and most patients exceeded the PASS criteria for the IKDC score. Patients were able to reach a high postoperative activity level. LEVEL OF EVIDENCE: Case Series; IV.

Biomechanical assessment of disease outcome in surgical interventions for medial meniscal posterior root tears: a finite element analysis.

BACKGROUND: The adverse consequences of medial meniscus posterior root tears have become increasingly familiar to surgeons, and treatment strategies have become increasingly abundant. In this paper, the finite element gait analysis method was used to explore the differences in the biomechanical characteristics of the knee joint under different conditions. METHODS: Based on CT computed tomography and MR images, (I) an intact knee (IK) model with bone, cartilage, meniscus and main ligaments was established. Based on this model, the posterior root of the medial meniscus was resected, and (ii) the partial tear (PT) model, (iii) the entire radial tear (ERT) model, and (iv) the entire oblique tear (EOT) model were established according to the scope and degree of resection. Then, the (v) meniscus repair (MR) model and (vi) partial meniscectomy (PM) model were developed according to the operation method. The differences in stress, displacement and contact area among different models were evaluated under ISO gait loading conditions. RESULTS: Under gait loading, there was no significant difference in the maximum stress of the medial and lateral tibiofemoral joints among the six models. Compared with the medial tibiofemoral joint stress of the IK model, the stress of the PM model increased by 8.3%, while that of the MR model decreased by 18.9%; at the same time, the contact stress of the medial tibiofemoral joint of the ERT and EOT models increased by 17.9 and 25.3%, respectively. The displacement of the medial meniscus in the ERT and EOT models was significantly larger than that in the IK model (P < 0.05), and the tibial and femoral contact areas of these two models were lower than those of the IK model (P < 0.05). CONCLUSIONS: The integrity of the posterior root of the medial meniscus plays an important role in maintaining normal tibial-femoral joint contact mechanics. Partial meniscectomy is not beneficial for improving the tibial-thigh contact situation. Meniscal repair has a positive effect on restoring the normal biomechanical properties of the medial meniscus.

Nineteen percent of meniscus repairs are being revised and failures frequently occur after the second postoperative year: a systematic review and meta-analysis with a minimum follow-up of 5 years.

PURPOSE: Meniscus repair has gained increasing interest over the last two decades as loss of meniscus tissue predisposes to early onset knee arthritis. Although there are many reports of meniscus repair outcome in short-term studies, data on the long-term outcome of meniscus repair are still scarce. The purpose of this meta-analysis was to evaluate the overall failure rate of meniscus repair with a minimum follow-up of 5 years. Additionally, possible factors influencing meniscus repair outcome were assessed. METHODS: PubMed and Scopus were searched for studies of the last 20 years reporting on meniscus repair outcome with a minimum follow-up of 5 years. The study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search terms used for this study were ([meniscus OR meniscal] AND repair). Titles and abstracts were evaluated by two authors independently. Using meta package of R (version 3.6.2), random-effect models were performed to pool failure rates. Subgroup analyses were performed and effect estimates in form of an odds ratio with 95% CIs were established. RESULTS: In total, 12 studies with 864 patients were included. Degenerative tears were excluded in two studies and one study only included traumatic meniscus tears. Other studies did not state whether the cause of meniscus tear was degenerative or traumatic. Studies reporting meniscus repair outcome on root repairs, revision anterior cruciate ligament reconstruction, discoid menisci or ramp lesions were excluded. Revision surgery was used as failure definition in all included studies. The overall failure rate of meniscal repair at a mean follow-up of 86 months was 19.1%. There was no significant difference in meniscus repair outcome when performed in combination with anterior cruciate ligament reconstruction compared to isolated meniscus repair (18.7% vs. 28%; n.s.) or when performed on the lateral meniscus compared to the medial meniscus (19.5% vs. 24.4%; n.s.). There was no significant difference of meniscus repair outcome between vertical/longitudinal tears and bucket-handle tears (n.s.). Thirty-six percent of meniscus repair failures occur after the second postoperative year. The only significant finding was that inside-out repair results in a lower failure rate compared to all-inside repair (5.6% vs. 22.3%; p = 0.009) at 5 years. CONCLUSION: The overall meniscus repair failure rate remains nineteen percent in long-term studies. The cause of failure is poorly documented, and it remains unclear whether failure of the meniscus repair itself or additional adjacent tears lead to revision surgery. Despite the given technical advantages of all-inside repair devices, this meta-analysis cannot demonstrate superior outcomes compared to inside-out or outside-in repair at 5 years. LEVEL OF EVIDENCE: IV.

Autologous semitendinosus tendon graft could function as a meniscal transplant.

PURPOSE: Meniscectomy results in poor knee function and increased risk for osteoarthritis. Meniscal allograft transplantation is not widely used due to costs and availability. The semitendinosus tendon (ST) has the potential to remodel and revascularize in an intraarticular environment, such as ACL reconstruction. The objective for this pilot study was to investigate whether the ST graft could function as a meniscal transplant. METHODS: The ST was doubled and sutured with running sutures and pull-out sutures in each end. Bone tunnels were used for root anchorage and the graft was sutured with allinside, inside-out and outside-in technique. The pull-out sutures were fixed over a button. Partial weight bearing was allowed with limited range of motion in a brace for the first 6 weeks. Evaluation was assessed using clinical examination, radiology and patient reported outcome. RESULTS: A total of seven patients have been included between January 2018 and June 2020. Six medial transplants and one lateral transplant were performed. Mean age was 29 years. Four patients had completed the 12-month follow-up. Improvements were noted for IKDC Global Score, KOOS pain subscale and Lysholm. MRI indicated that the transplant become more wedge-like with visible roots and minor protrusion. CONCLUSIONS: Even though this is primarily a technical report the follow-up data indicate that the transplant survives and adapts in shape and capabilities to an original meniscus. There were no adverse events and the patients seem to improve in terms of pain and quality of life.