Reconstruction of medial meniscus posterior portion deficiency in pigs with an autologous patellar tendon graft: an experimental study.

OBJECTIVE: This study was performed to investigate the effectiveness of two surgical procedures, autologous patellar tendon graft reconstruction and trans-tibial plateau pull-out repair, using a pig model. The primary focus was to assess the repair capability of medial meniscus posterior portion (MMPP) deficiency, the overall structural integrity of the meniscus, and protection of the femoral and tibial cartilage between the two surgical groups. The overall aim was to provide experimental guidelines for clinical research using these findings. METHODS: Twelve pigs were selected to establish a model of injury to the MMPP 10 mm from the insertion point of the tibial plateau. They were randomly divided into three groups of four animals each: reconstruction (autologous tendon graft reconstruction of the MMPP), pull-out repair (suture repair of the MMPP via a trans-tibial plateau bone tunnel), and control (use of a normal medial meniscus as the negative control). The animals were euthanized 12 weeks postoperatively for evaluation of the meniscus, assessment of tendon bone healing, and gross observation of knee joint cartilage. The tibial and femoral cartilage injuries were evaluated using the International Society for Cartilage Repair (ICRS) grade and Mankin score. Histological and immunohistochemical staining was conducted on the meniscus-tendon junction area, primary meniscus, and tendons. The Ishida score was used to evaluate the regenerated meniscus in the reconstruction group. Magnetic resonance imaging (MRI) was used to evaluate meniscal healing. RESULTS: All 12 pigs recovered well after surgery; all incisions healed without infection, and no obvious complications occurred. Gross observation revealed superior results in the reconstruction and pull-out repair groups compared with the control group. In the tibial cartilage, the reconstruction group had ICRS grade I injury whereas the pull-out repair and control groups had ICRS grade II and III injury, respectively. The Mankin score was significantly different between the reconstruction and control groups; histological staining showed that the structure of the regenerated meniscus in the reconstruction group was similar to that of the original meniscus. Immunohistochemical staining showed that the degree of type I and II collagen staining was similar between the regenerated meniscus and the original meniscus in the reconstruction group. The Ishida score was not significantly different between the regenerated meniscus and the normal primary meniscus in the reconstruction group. MRI showed that the MMPP in the reconstruction and pull-out repair groups had fully healed, whereas that in the control group had not healed. CONCLUSION: Autologous patellar tendon graft reconstruction of the MMPP can generate a fibrocartilage-like regenerative meniscus. Both reconstruction and pull-out repair can preserve the structural integrity of the meniscus, promote healing of the MMPP, delay meniscal degeneration, and protect the knee cartilage.

Evaluation of Remodeling and Extrusion of Polyurethane Meniscal Implants after Meniscus Reconstruction using Ultrasonography.

INTRODUCTION: Meniscal tears are among the most common indications for knee arthroscopy. Artificial polyurethane scaffolds have demonstrated efficacy in reducing pain and promoting the growth of normal meniscal tissue, with high absorption rates facilitating full tissue regeneration. AIMS: This study aimed to evaluate the remodeling of polyurethane meniscal implants post-reconstruction using ultrasonography. This imaging technique not only assesses changes in implant properties, such as echogenicity, but also the shape changes during functional examination. METHODS: The assessment of meniscal extrusion, comparing size at rest and under weight-bearing, is an indirect parameter that provides insight into the physical properties of the remodeling implant, with greater extrusion indicating reduced stiffness and inferior physical properties of the meniscus. Ultrasonography has the valuable advantage of allowing for assessment of the blood supply to the meniscus through Power Doppler imaging. RESULTS: The presence of vessels within the meniscal implants serves as evidence of ongoing remodeling. The study included 35 patients (13 female, 22 male; mean age 41.6 years, range 18-66) who underwent arthroscopic meniscal reconstruction with polyurethane implants, with an average time from surgery of 2.8 years (range 0.3-4.5 years). Results showed complete (29.7%), significant (45.9%), or moderate (16.2%) remodeling into natural meniscal tissue in 91.8% of the implants. CONCLUSION: The mean values of extrusion in the supine position and during 90-degree flexion were significantly greater in the operated limb (2.603) compared to the contralateral limb (1.978; t(35) = 2.442; P < 0.05). No significant differences in extrusion were found between the limbs in a standing position, indicating favorable physical properties of the polyurethane meniscal implants. Further ultrasonography studies of meniscal scaffolds are deemed relevant.

Perioperative outcomes in isolated versus multiligamentous anterior cruciate ligament reconstruction: a retrospective cohort analysis.

PURPOSE: The outcomes of anterior cruciate ligament reconstruction in the setting of multiligamentous knee injury (M-ACLR) have not been well characterized compared to isolated ACLR (I-ACLR). This study aims to characterize and compare short-term outcomes between I-ACLR and M-ACLR. METHODS: This is a retrospective cohort analysis of the American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2017. Current Procedural Terminology codes were used to identify and compare elective I- and M-ACLR patients, excluding patients undergoing concomitant meniscal or chondral procedures. Patient demographics and outcomes after I- and M-ACLR were compared using bivariate analysis. Multiple logistic regression analyzed if multiligamentous ACLR was an independent risk factor for adverse outcomes. RESULTS: There was a total of 13,131 ACLR cases, of which 341 were multiligamentous cases. The modified fragility index-5 was higher in multiligamentous ACLR (p < 0.001). Multiligamentous ACLR had worse perioperative outcomes, with higher rate of all complications (3.8%, p = 0.013), operative time > 1.5 h (p < 0.001), length of stay (LOS) ≥ 1 day (p < 0.001), wound complication (2.1%, p = 0.001), and intra- or post-op transfusions (p < 0.001). In multiple logistic regression, multiligamentous ACLR was an independent risk factor for LOS ≥ 1 (odds ratio [OR] 5.8), and intra-/post-op transfusion (OR 215.1) and wound complications (OR 2.4). M-ACLR was not an independent risk factor for any complication, reoperation at 30 days, readmission, urinary tract infection (UTI), or venous thromboembolism (VTE). CONCLUSION: M-ACLR generally had worse outcomes than I-ACLR, including longer LOS, need for perioperative transfusions, and wound complications.

Optimized Allogenic Decellularized Meniscal Scaffold Modified by Collagen Affinity Stromal Cell-Derived Factor SDF1α for Meniscal Regeneration: A 6- and 12-Week Animal Study in a Rabbit Model.

BACKGROUND: Total meniscectomy for treating massive meniscal tears may lead to joint instability, cartilage degeneration, and even progressive osteoarthritis. The meniscal substitution strategies for advancing reconstruction of the meniscus deserve further investigation. HYPOTHESIS: A decellularized meniscal scaffold (DMS) modified with collagen affinity stromal cell-derived factor (C-SDF1α) may facilitate meniscal regeneration and protect cartilage from abrasion. STUDY DESIGN: Controlled laboratory study. METHODS: The authors first modified DMS with C-SDF1α to fabricate a new meniscal graft (DMS-CBD [collagen-binding domain]). Second, they performed in vitro studies to evaluate the release dynamics, biocompatibility, and differentiation inducibility (osteogenic, chondrogenic, and tenogenic differentiation) on human bone marrow mesenchymal stem cells. Using in vivo studies, they subjected rabbits that received medial meniscectomy to a transplantation procedure to implement their meniscal graft. At postoperative weeks 6 and 12, the meniscal regeneration outcomes and chondroprotective efficacy of the new meniscal graft were evaluated by macroscopic observation, histology, micromechanics, and immunohistochemistry tests. RESULTS: In in vitro studies, the optimized DMS-CBD graft showed notable biocompatibility, releasing efficiency, and chondrogenic inducibility. In in vivo studies, the implanted DMS-CBD graft after total meniscectomy promoted the migration of cells and extracellular matrix deposition in transplantation and further facilitated meniscal regeneration and protected articular cartilage from degeneration. CONCLUSION: The new meniscal graft (DMS-CBD) accelerated extracellular matrix deposition and meniscal regeneration and protected articular cartilage from degeneration. CLINICAL RELEVANCE: The results demonstrate that the DMS-CBD graft can serve as a potential meniscal substitution after meniscectomy.

Single- or two-stage revision after failed ACL reconstruction: No differences in re-revision rates and clinical outcomes.

PURPOSE: The surgeons' choice of a single-stage or a two-stage procedure in revision anterior cruciate ligament reconstruction (ACLr) is based on the possibility of reuse of the tibia and femoral bone tunnels after primary ACLr. The purpose of this study was to compare failure rates and clinical outcomes following single-stage and two-stage ACL revisions in a cohort of patients from The Danish Knee Ligament Reconstruction Registry. METHODS: Patients identified from 2005 to 2022 with ACL revision and met the following criteria: minimum 2-year follow-up, isolated ACL revision and registered single- or two-stage ACL revision. The primary outcome was ACL re-revision rate. Secondary outcomes were arthrometer sagittal knee laxity (side-to-side difference) and pivot shift (rotational stability difference) evaluated at 1-year follow up. RESULTS: One thousand five hundred seventy-four ACL revisions were included in the study (1331 = single-stage and 243 = two stage). Baseline characteristics showed no difference in relation to age, gender, knee laxity, pivot shift, meniscus injury, cartilage damage or injury mechanism between the two groups. Significant differences were found in relation to the type of graft. No statistical difference in 2-years revision rates between single-stage group 2.79 (95% CI 2.03-3.84) and two-stage group 2.93 (95% CI 1.41-6.05) was found. No significant difference was seen in knee laxity and pivot shift between stage-groups at 1-year follow up. Both groups demonstrated significant improvements in knee stability from baseline to 1-year follow-up. CONCLUSION: The present study found that ACL revision outcomes were similar in terms of rerevision rates and knee laxity for patients managed with a single- or a two-stage surgical strategy. LEVEL OF EVIDENCE: Level III.

Short-Term but Not Long-Term Knee Symptoms and Functional Improvements of Tissue Engineering Strategy for Meniscus Defects: A Systematic Review of Clinical Studies.

PURPOSE: To investigate the up-to-date clinical outcomes of tissue-engineered meniscus implants for meniscus defects. METHODS: A search was performed by 3 independent reviewers on PubMed, MEDLINE, EMBASE, and Cochrane from 2016 to June 18, 2023, with the term "meniscus" with all the following terms: "scaffolds," "constructs," "implant," and "tissue engineering." Inclusion criteria included "Clinical trials" and "English language articles" that involved isolated meniscus tissue engineering strategies for meniscus injuries. Only Level I to IV clinical studies were considered. The modified Coleman Methodology score was used for quality analysis of included clinical trials. The Methodological Index for Non-Randomized Studies was employed for analysis of the risk of study bias and methodological quality. RESULTS: The search identified 2,280 articles, and finally 19 original clinical trials meeting the inclusion criteria were included. Three types of tissue-engineered meniscus implants (CMI-Menaflex, Actifit, and NUsurface) have been clinically evaluated for meniscus reconstruction. Lack of standardized outcome measures and imaging protocols limits comparison between studies. CONCLUSIONS: Tissue-engineered meniscus implants can provide short-term knee symptom and function improvements, but no implants have been shown to propose significant long-term benefits for meniscus defects. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Functional performance tests, clinical measurements, and patient-reported outcome measures do not correlate as outcomes 1 year after anterior cruciate ligament reconstruction.

PURPOSE: The results after anterior cruciate ligament reconstruction (ACLR) are evaluated by laxity measures, functional tests, and patients' perception by patient-reported outcome measures (PROMs). It is not known, if one of these evaluation instruments is representative or if outcome scores from all must be reported to obtain a full evaluation of the condition. The aim was to study the correlations between these three types of outcomes 1 year after primary ACLR. METHOD: All adult patients (range 18-45 years) who had an ACLR between 1.1.2019 and 31.12.2021 were offered 1-year follow-up by an independent observer. Preoperative information about knee laxity and peroperative information about the condition of menisci and cartilage were registered. At 1-year follow-up clinical and instrumented knee stability and function assessed by four different hop tests were registered. Patients completed four PROMs (the Subjective International Knee Documentation Committee (IKDC) score, the Knee Numeric-Entity Evaluation Score (KNEES-ACL), the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Lysholm score) and Tegner activity scale and answered anchor questions regarding satisfaction and willingness to repeat the operation. RESULTS: A total of 190 adults attended the 1-year follow-up and 151 had all assessments. There were only a few positive and weak correlations between performance tests and PROMS and between clinical measurements and PROMS (r = 0.00-0.38), and the majority were of negligible strength. Tegner score had in general the highest correlation (low to moderate). The highest correlation was 0.53 (moderate) between the anchor question about patient satisfaction and Lysholm/IKDC scores. There was no difference in the correlations depending on meniscal condition. CONCLUSIONS: In ACLR patients there was no clinically relevant correlation between scores obtained by PROMs, a battery of functional performance tests and instrumented laxity of the knee at 1-year follow-up. Therefore, one type of outcome cannot represent the others. This is an argument for always to include and report all three types of outcomes, and conclusions based on one type of outcome may not be sufficient. LEVEL OF EVIDENCE: II.

Rates of subsequent surgeries after meniscus repair with and without concurrent anterior cruciate ligament reconstruction.

OBJECTIVES: The purpose of this study was to compare the rates of secondary knee surgery for patients undergoing meniscus repair with or without concurrent anterior cruciate ligament reconstruction (ACLr). METHODS: Utilizing a large national database, patients with meniscal repair with or without concurrent arthroscopic ACLr were identified. The two cohorts were then queried for secondary surgical procedures of the knee within the following 2 years. Frequency, age distribution, rates of secondary surgery, and type of secondary procedures performed were compared. RESULTS: In total, 1,585 patients were identified: meniscus repair with ACLr was performed for 1,006 (63.5%) and isolated meniscal repair was performed for 579 (36.5%). Minimum of two year follow up was present for 487 (30.7% of the overall study population). Secondary surgery rates were not significantly different between meniscus repair with concurrent ACLr and isolated meniscus repairs with an overall mean follow up of 13 years (1.5-24 years) (10.6% vs. 13.6%, p = 0.126). For the 2 year follow up cohort, secondary surgery rates were not significantly different (19.3% vs. 25.6%, p = 0.1098). There were no differences in survivorship patterns between the two procedures, both in the larger cohort (p = 0.2016), and the cohort with minimum 2-year follow-up (p = 0.0586). CONCLUSION: The current study assessed secondary surgery rates in patients undergoing meniscus repair with or without concurrent ACLr in a large patient database. Based on this data, no significant difference in rates of secondary knee surgery was identified.

Graft failure within 2 years of isolated anterior cruciate ligament reconstruction is associated with increased risk of secondary meniscus tears.

PURPOSE: A debilitating complication following anterior cruciate ligament reconstruction is a secondary meniscus tear. Currently, the literature is mixed regarding the risk factors associated with the incidence of secondary meniscus tears. The aim of this study was to investigate risk factors associated with meniscus tears following an isolated primary anterior cruciate ligament reconstruction. ACL graft failure was hypothesized to be the strongest risk factor for secondary meniscal injury occurrence. METHODS: A retrospective cohort analysis was performed using the PearlDiver Database. Patients with a primary anterior cruciate ligament reconstruction were identified in the database. Patients with concomitant knee ligament injury or meniscus injury present at the time the index procedure were excluded. Patients were grouped to those who had a secondary meniscus tear within 2 years following anterior cruciate ligament reconstruction and those who did not. Univariate analysis and multivariable regression analysis was conducted to identify significant risk factors for a secondary meniscus tear. RESULTS: There were 25,622 patients meeting criteria for inclusion in this study. Within 2 years from the primary anterior cruciate ligament reconstruction, there were 1,781 patients (7.0%) that experienced a meniscus tear. Graft failure had the highest odds of having a postoperative meniscus tear within 2 years (OR: 4.1; CI 3.5-4.8; p < 0.002). Additional significant risk factors included tobacco use (OR: 2.0; CI 1.0-3.1; p < 0.001), increased Charlson Comorbidity Index (OR: 1.2; CI 1.1-1.4), male gender (OR: 1.1; CI 1.1-1.2; p < 0.001), obesity (OR: 1.1; CI 1.1-1.2; p < 0.001), delayed surgery (OR:1.1; CI 1.1-1.2; p < 0.002), and patients age 30 and older (OR: 1.0; CI 1.0-1.0; p < 0.001). CONCLUSIONS: This study found that anterior cruciate ligament graft failure is the strongest predictor of post-operative meniscus tears. Other risk factors, including tobacco use, increased CCI, male gender, obesity, delayed surgery, and age 30 and older, were established, with several being modifiable. Therefore, targeted preoperative optimization of modifiable risk factors and postoperative protocols may reduce the risk of secondary meniscus tears. LEVEL OF EVIDENCE: Level III, prognostic trial.

Editorial Commentary: Meniscal Extrusion.

With the improved recognition of meniscal root tears over the past decade, it has become clear that root repairs are necessary in most patients indicated for a repair to prevent the further progression of osteoarthritis. Root repairs are cost beneficial to and prevent the early need for a total knee arthroplasty. As further postoperative follow-up occurs for root repairs, we have found that most patients have significantly improved patient-reported outcomes, while it is still clear that further clinical outcome study as well as further refinement of surgical technique is necessary. The next thing that we have to investigate is how to prevent recurrent meniscal extrusion after a root repair. Nonanatomic repair significantly alters tibiofemoral biomechanics and results in notably increased meniscal extrusion. In contrast, biomechanical studies show anatomic repair of the meniscus attachment within 1 cm of the meniscus attachment site restores joint loading close to normal.

Knee Injury and Osteoarthritis Outcome Score Interpretation Thresholds at 3 and 12 Months After Arthroscopic Meniscal Surgery. What Changes, and What Stays the Same?

OBJECTIVE: To evaluate the change in minimal important change (MIC), patient acceptable symptom state (PASS), and treatment failure (TF) thresholds for the Knee injury and Osteoarthritis Outcome Score (KOOS) from 3 to 12 months following arthroscopic meniscus surgery. DESIGN: Retrospective cohort study. METHODS: We included patients from the Knee Arthroscopy Cohort Southern Denmark who had meniscus surgery between 2013 and 2015. We calculated the interpretation threshold values for MIC, PASS, and TF using an anchor-based adjusted predictive modeling method. Thresholds at 3 and 12 months postoperatively were compared to evaluate changes over time. RESULTS: The proportions of people who reported a clinically relevant improvement, or their symptoms being acceptable, increased by 10% to 15% points from 3 to 12 months after surgery. MIC thresholds for the 5 KOOS subscales remained stable from 3 to 12 months with statistically nonsignificant differences (95% confidence intervals) ranging from -0.3 (-3.0, 2.6) to -2.4 (-6.1, 1.3). All PASS thresholds except for quality of life (QOL) decreased by -6.5 (-11.8, -1.5) to -3.7 (-7.1, -0.4) points, indicating that higher symptom levels were accepted at 12 months. In contrast, the proportion reporting their treatment to have failed remained stable over time (19% and 17%). For QOL, a 7.4 (2.0, 13.2) higher TF threshold at 12 months suggested that improved QOL was required to not consider that the treatment had failed. CONCLUSION: More patients reported being improved at 1 year compared to at 3 months following meniscus surgery. The KOOS MIC thresholds were stable over time, whereas time-specific PASS values should be applied after meniscus surgery. J Orthop Sports Phys Ther 2023;53(11):685-702. Epub 3 October 2023. doi:10.2519/jospt.2023.11993.

Availability of Consumer Prices for Arthroscopic Meniscus Surgery.

The purpose is to examine the availability of consumer pricing information for arthroscopic meniscal surgery in the United States. Secondary objectives were comparing the price of meniscal repair to meniscectomy and regional pricing differences. Orthopaedic sports medicine clinics were sorted by state and randomly selected from American Orthopaedic Society for Sports Medicine's online directory. Following standardized script, each clinic was called a maximum of three times to obtain pricing information for meniscal surgery. A total of 1,008 distinct orthopaedic sport medicine practices were contacted. Six (6%) clinics were able to provide complete bundle pricing, and 183 (18.2%) clinics were able to provide physician-only fees for either meniscectomy or meniscal repair. Physician-only fees and bundle pricing were significantly less for meniscal repairs as compared to meniscectomies. There were no geographic regional differences in pricing for physician-only fees. There is a paucity of information regarding price transparency for arthroscopic meniscal surgery. (Journal of Surgical Orthopaedic Advances 32(2):083-087, 2023).

Efficacy of meniscus suture absorbability on meniscus healing success rate via second-look arthroscopy after meniscal repair: a systematic review and meta-analysis.

BACKGROUND: To preserve the meniscus's function, repairing the torn meniscus has become a common understanding. After which, the search for the ideal suture material is continuous. However, it is still controversial about the efficacy of suture absorbability on meniscus healing. METHODS: This review is designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. INCLUSION CRITERIA: (1) Studies on meniscus repair; (2) Second-look arthroscopy was performed; (3) The meniscus was repaired by absorbable and non-absorbable sutures; (4) The healing condition of repaired meniscus via second-look arthroscopy was described. EXCLUSION CRITERIA: (1) Animal studies, cadaveric studies, or in vitro research; (2) Meniscus transplantation; (3) Open meniscus repair; (4) Reviews, meta-analysis, case reports, letters, and comments; (5) non-English studies. MEDLINE, Embase, and Cochrane Database were searched up to October 2022. Risk of bias and methodology quality of included literature were assessed according to ROBINS-I and the modified Coleman Methodological Scale (MCMS). Descriptive analysis was performed, and meta-analysis was completed by RevMan5.4.1. RESULTS: Four studies were included in the systematic review. Among them, three studies were brought into the meta-analysis, including 1 cohort study and 2 case series studies about 130 patients with meniscal tears combined with anterior cruciate ligament injury. Forty-two cases were repaired by absorbable sutures, and 88 were repaired by non-absorbable sutures. Using the fixed effect model, there was a statistical difference in the healing success rate between the absorbable and the non-absorbable groups [RR1.20, 95%CI (1.03, 1.40)]. CONCLUSION: In early and limited studies, insufficient evidence supports that non-absorbable sutures in meniscus repair surgery could improve meniscal healing success rate under second-look arthroscopy compared with absorbable sutures. In contrast, available data suggest that absorbable sutures have an advantage in meniscal healing. TRIAL REGISTRATION: The review was registered in the PROSPERO System Review International Pre-Registration System (Registration number CRD42021283739).

Medial Meniscotibial Ligament of the Knee: A Step by-Step Dissection / Ligamento meniscotibial medial do joelho: Uma dissecção passo a passo

Abstract Objective Considerable attention has been paid to meniscotibial ligaments (MTLs), also known as coronary ligaments, especially after the "Save the Meniscus" initiative gained importance among knee surgeons. Technically challenging, the diagnosis and treatment of ramp lesion show the importance of MTLs. These ligaments were discovered long ago, but their contribution to knee stability has only recently been studied and still lacks information. Thus, the aim of the present study was to describe step-by-step an dissection technique of the medial MTL, efficient, reproducible and that may lead to further research. Method Twenty fresh cadaver knees were used, with no preference for sex or age. The knees were dissected using the same technique standardized by our team. Each dissection step was recorded digitally. Results The medial MTL was found in all 20 knees studied using the aforementioned technique. In our sample, the medial MTL exhibited an average length of 70.0 ± 13.4 mm and width of 32.25 ± 3.09 mm, thickness of 35.3 ± 2.7 mm and weight of 0.672 ± 0.134 g. In all the cases, the medial MTL originated proximally and deeply to the deep MTL in the tibia. Conclusion We describe a simple effective and reproducible medial MTL dissection technique that makes it possible to identify the ligament over the entire medial extension of the knee.

Resumo Objetivo Considerável atenção tem sido dada aos ligamentos meniscotibiais (LMT), também conhecidos como ligamentos coronários, especialmente depois que a iniciativa "Salve o Menisco" ganhou importância entre os cirurgiões de joelho. Tecnicamente desafiadores, o diagnóstico e o tratamento da lesão em rampa são importantes nos LMTs. Esses ligamentos foram descobertos há muito tempo, mas sua contribuição para a estabilidade do joelho foi recentemente estudada e ainda carece de informações. Assim, o objetivo deste estudo foi descrever passo a passo uma técnica de dissecção medial do LMT que é eficiente, reprodutível e que possa levar a novas pesquisas. Métodos Foram utilizados 20 joelhos de cadáveres frescos, sem preferência por sexo ou idade. Os joelhos foram dissecados com a mesma técnica padronizada por nossa equipe. Cada etapa da dissecação foi gravada digitalmente. Resultados O LMT medial foi encontrado em todos os 20 joelhos estudados com a técnica supracitada. Em nossa amostra, o LMT medial apresentou comprimento médio de 70,0 ± 13,4 mm e largura de 32,25 ± 3,09 mm, além de espessura de 35,3 ± 2,7 mm e peso de 0,672 ± 0,134 g. Em todos os casos, a origem do LMT medial era proximal e profunda em relação ao LMT profundo na tíbia. Conclusão Descrevemos uma técnica de dissecção simples do LMT medial que é eficaz, reprodutível e permite a identificação do ligamento em toda a extensão medial do joelho.

Horizontal Cleavage Meniscus Tears: Biomechanics, Indications, Techniques, and Outcomes.

¼ Accounting for up to 24% of all meniscus tears, horizontal cleavage tears (HCTs) are a common pathology orthopaedic practitioners should be comfortable managing.¼ Historically, HCTs were treated with partial meniscectomy; however, recent studies have demonstrated that these procedures have an adverse biomechanical effect, while HCT repairs restore the knee's natural biomechanics.¼ Indications for the surgical repair of HCTs remain disputed, but surgery is generally considered for young, active patients and older patients without significant concomitant osteoarthritis.¼ Early clinical findings surrounding HCT repair are promising. They suggest that this treatment adequately restores meniscus mechanics, leads to good knee functional outcomes, and results in a high likelihood of return to preinjury activity levels.

Ten-Year Outcomes of Second-Generation, All-Inside Meniscal Repair in the Setting of ACL Reconstruction.

BACKGROUND: Meniscal repair is the goal, whenever possible, for the treatment of meniscal injury. The purpose of this study was to evaluate the long-term clinical success of meniscal repair performed with a second-generation, all-inside repair device with a concomitant anterior cruciate ligament (ACL) reconstruction. METHODS: This was a retrospective review of prospectively collected patients who underwent meniscal repair by a single surgeon using the all-inside FAST-FIX Meniscal Repair System (Smith & Nephew) in conjunction with a concurrent ACL reconstruction. Eighty-one meniscal repairs (81 patients) were identified: 59 medial repairs and 22 lateral repairs. Clinical failure was defined as repeat surgical intervention involving resection or revision repair. Clinical outcomes were assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, and Marx Activity Rating Scale score. RESULTS: Ten-year follow-up was obtained for 85% (69) of 81 patients. Nine patients (13% of 69) underwent a failed meniscal repair (6 medial, 3 lateral), corresponding to a failure rate of 12% (6 of 50) for medial repairs and 16% (3 of 19) for lateral repairs. The mean time to failure was 2.8 years (range, 1.2 to 5.6 years) for the medial repairs and 5.8 years (range, 4.2 to 7.0 years) for the lateral repairs (p = 0.002). There was no difference in mean patient age, sex, body mass index, graft type, or number of sutures utilized between successful repairs and failures. Postoperative KOOS and IKDC outcome scores significantly improved over baseline scores (p < 0.001). There was no significant difference in patient-reported outcomes at 10 years between the group with successful repairs and those who had a failed repair. CONCLUSIONS: This report of long-term follow-up results of primary second-generation, all-inside meniscal repair demonstrates its relative success when it is performed with concurrent ACL reconstruction. After a minimum follow-up of 10 years, 84% to 88% of the patients continued to demonstrate successful repair. Failure of medial meniscal repairs occurred significantly earlier compared with lateral meniscal repairs. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Potential causal role of synovial complement system activation in the development of post-traumatic osteoarthritis after anterior cruciate ligament injury or meniscus tear.

Anterior cruciate ligament (ACL) injury and meniscal tear (MT) are major causal factors for developing post-traumatic osteoarthritis (PTOA), but the biological mechanism(s) are uncertain. After these structural damages, the synovium could be affected by complement activation that normally occurs in response to tissue injury. We explored the presence of complement proteins, activation products, and immune cells, in discarded surgical synovial tissue (DSST) collected during arthroscopic ACL reconstructive surgery, MT-related meniscectomy and from patients with OA. Multiplexed immunohistochemistry (MIHC) was used to determine the presence of complement proteins, receptors and immune cells from ACL, MT, OA synovial tissue vs. uninjured controls. Examination of synovium from uninjured control tissues did not reveal the presence of complement or immune cells. However, DSST from patients undergoing ACL and MT repair demonstrated increases in both features. In ACL DSST, a significantly higher percentage of C4d+, CFH+, CFHR4+ and C5b-9+ synovial cells were present compared with MT DSST, but no major differences were seen between ACL and OA DSST. Increased cells expressing C3aR1 and C5aR1, and a significant increase in mast cells and macrophages, were found in ACL as compared to MT synovium. Conversely, the percentage of monocytes was increased in the MT synovium. Our data demonstrate that complement is activated in the synovium and is associated with immune cell infiltration, with a more pronounced effect following ACL as compared to MT injury. Complement activation, associated with an increase in mast cells and macrophages after ACL injury and/or MT, may contribute to the development of PTOA.

Repair of a meniscus tear within 3 weeks after trauma significantly reduces the likelihood of a recurrent tear compared with later repairs.

PURPOSE: To evaluate the potential benefit of meniscus tear repair within 3 weeks after rupture compared with more than 3 weeks after rupture. METHODS: Ninety-one patients (95 menisci) underwent repair within 3 weeks after meniscus rupture [Group 1] and 15 patients (17 menisci) [Group 2] underwent repair more than 3 weeks after rupture. The posterior part of the ruptured meniscus was repaired with Contour Arrows®, using a Crossbow as the insertion instrument, whereas the middle third was repaired by inserting PDS 2.0 stitches using a Meniscus Mender® outside-in device. The patients were followed-up for a mean(SD) 8.9 years (range: 1-12 years). RESULTS: Of the 91 patients (95 menisci) in Group 1, 88 (96.7%) healed without complications. One meniscus in one patient did not heal after 11 months, requiring resection. Two other menisci in two other patients showed partially healed tears. This part was removed while preserving most of the meniscus (failure rate: 3/91 patients: 3.3%). The other 88 patients recovered without complaints and participated in sports without restraint. Four menisci in four patients experienced a second sports-related incident, resulting in a renewed tear between 12 months and 3 years. These tears were repaired successfully again. Of the 15 patients in Group 2, 12 (80.0%) healed without complications. The ruptured part of the remaining menisci in the other three patients, (20%) was removed, with all patients remaining symptom-free until the end of follow-up. Rates of treatment failure differed significantly in these two groups (3.3% vs 20.0%, p = 0.04). CONCLUSIONS: The overall failure rate was significantly lower in patients who underwent meniscus repair within 3 weeks than in those who underwent repair at 3 weeks (or more) after the trauma. Thus, early repair of meniscus tears is beneficial, and can prevent failure of meniscus repair surgery. LEVEL OF EVIDENCE: III.

Repairing Avascular Meniscal Lesions by Recruiting Endogenous Targeted Cells Through Bispecific Synovial-Meniscal Aptamers.

BACKGROUND: Tissue engineering is a promising treatment option for meniscal lesions in the avascular area, but a favorable cell source and its utilization in tissue-engineered menisci remain uncertain. Therefore, a more controllable and convenient method for cell recruitment is required. HYPOTHESIS: Circular bispecific synovial-meniscal (S-M) aptamers with a gelatin methacryloyl (GelMA) hydrogel can recruit endogenous synovial and meniscal cells to the site of the defect, thereby promoting in situ meniscal regeneration and chondroprotection. STUDY DESIGN: Controlled laboratory study. METHODS: Synovial and meniscal aptamers were filtered through systematic evolution of ligands by exponential enrichment (SELEX) and cross-linked to synthesize the S-M aptamer. A GelMA-aptamer system was constructed. An in vitro analysis of the bi-recruitment of synovial and meniscal cells was performed, and the migration and proliferation of the GelMA-aptamer hydrogel were also tested. For the in vivo assay, rabbits (n = 90) with meniscal defects in the avascular zone were divided into 3 groups: repair with the GelMA-aptamer hydrogel (GelMA-aptamer group), repair with the GelMA hydrogel (GelMA group), and no repair (blank group). Regeneration of the repaired meniscus and degeneration of the cartilage were assessed by gross and histological evaluations at 4, 8, and 12 weeks postoperatively. The mechanical properties of repaired menisci were also evaluated. RESULTS: In vitro synovial and meniscal cells were recruited simultaneously by the S-M aptamer with high affiliation and specificity. The GelMA-aptamer hydrogel promoted the migration of targeted cells. Compared with the other groups, the GelMA-aptamer group showed enhanced fibrocartilaginous regeneration, lower cartilage degeneration, and better mechanical strength at 12 weeks after meniscal repair. CONCLUSION/CLINICAL RELEVANCE: Bispecific S-M aptamers could be used for avascular meniscal repair by recruiting endogenous synovial and meniscal cells and promoting fibrocartilaginous regeneration.

Survival of anterior cruciate ligament reconstructions in active-duty military populations.

PURPOSE: Anterior cruciate ligament tears and anterior cruciate ligament reconstruction (ACLR) are common in young athletes. The modifiable and non-modifiable factors contributing to ACLR failure and reoperation are incompletely understood. The purpose of this study was to determine ACLR failure rates in a physically high-demand population and identify the patient-specific risk factors, including prolonged time between diagnosis and surgical correction, that portend failure. METHODS: A consecutive series of military service members with ACLR with and without concomitant procedures (meniscus [M] and/or cartilage [C]) done at military facilities between 2008 and 2011 was completed via the Military Health System Data Repository. This was a consecutive series of patients without a history of knee surgery for two years prior to the primary ACLR. Kaplan-Meier survival curves were estimated and evaluated with Wilcoxon test. Cox proportional hazard models calculated hazard ratios (HR) with 95% confidence intervals (95% CI) to identify demographic and surgical factors that influenced ACLR failure. RESULTS: Of the 2735 primary ACLRs included in the study, 484/2,735 (18%) experienced ACLR failure within four years, including (261/2,735) (10%) undergoing revision ACLR and (224/2,735) (8%) due to medical separation. The factors that increased failure include Army Service (HR 2.19, 95% CI 1.67, 2.87), > 180 days from injury to ACLR (HR 1.550, 95% CI 1.157, 2.076), tobacco use (HR 1.429 95% CI 1.174, 1.738), and younger patient age (HR 1.024, 95% CI 1.004, 1.044). CONCLUSION: The overall clinical failure rate of service members with ACLR is 17.7% with minimum four-year follow-up, where more patients are likely to fail due to revision surgery than medical separation. The cumulative probability of survival at 4 years was 78.5%. Smoking cessation and treating ACLR patients promptly are modifiable risk factors impacting either graft failure or medical separation. LEVEL OF EVIDENCE: Level III.