Outcome of meniscal repairs in paediatric population:A tertiary centre experience

BACKGROUND Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis.However,there is limited data in the literature on meniscal repair outcomes in skeletally immature patients.AIM To evaluate the re-operation rate and functional outcomes of meniscal repairs in children and adolescents.METHODS We performed a retrospective review of all patients who underwent arthroscopic meniscal repair surgery between January 2007 and January 2018.All patients were under the age of 18 at the time of surgery.Procedures were all performed by a single surgeon.Information was gathered from our hospital Electronic Patient Records system.The primary outcome measure was re-operation rate(need for further surgery on the same meniscus).Secondary outcome measures were surgical complications and patient reported outcome measures that were International Knee Documentation Committee(IKDC),Tegner and Lysholm scores.RESULTS We identified 59 patients who underwent 66 All-inside meniscal repairs(32 medial meniscus and 34 Lateral meniscus).Meniscal repairs were performed utilizing FasT-Fix(Smith and Nephew)implants.There were 37 males and 22 females with an average age of 14 years(range 6-16).The average follow-up time was 53 months(range 26-140).Six patients had concomitant anterior cruciate ligament reconstruction surgery along with the meniscal repair.There were no requiring further meniscal repairs and 9 patients underwent partial meniscectomies.The mean postoperative IKDC score was 88(44-100),Tegner score was 7(2-10)and Lysholm score was 94(57-100).CONCLUSION Our results showed that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option that has a low failure rate and good postoperative clinical with the advantage of preserving meniscal tissues.

Failure rate,return-to-sports and magnetic resonance imaging after meniscal repair:119 patients with 7 years mean follow up

BACKGROUND One of the most important factors to consider in relation to meniscal repair is the high failure rate reported in the existing literature.AIM To evaluate failure rates,return to sports(RTS)rate,clinical outcomes and magnetic resonance image(MRI)evaluation after meniscus suture repair for longitudinal tears at a minimum 2-year-follow-up.METHODS We conducted a retrospective review of meniscal repairs between January 2004 and December 2018.All patients treated for longitudinal tears associated or not with an anterior cruciate ligament reconstruction(ACL-R)were included.Meniscal ramp lesions,radial and root tears,associated with multiligament injuries,tibial fracture and meniscal allograft transplants were excluded.Surgical details and failure rate,defined as symptomatic patients who underwent a revision surgery,were analyzed.As isolated bucket handle tears(BHTs)were usually associated with higher failure rates,we compared BHTs and not BHTs associated or not with an ACL-R.Since 2014,the inside-out technique using cannulas and suture needles with 2-0 Tycron began to predominate.In addition,the number of stitches per repair was increased.In view of differences in surgical technique,we compared two different cohorts:before and after 2014.We recorded the RTS according to the level achieved and the time to RTS.Lysholm and IKDC scores were recorded.Patients were studied with x-rays and MRI as standard postoperative control.RESULTS One hundred and nineteen patients were included with a mean follow up of 7 years(SD:4.08).Overall failure rate was 20.3%at a mean 20.1 mo.No statistically significant differences were found when comparing failure for medial and lateral meniscal repair(22.7%and 15.3%,P=0.36),BHTs and not BHTs(26%and 17.6%,P=0.27),isolated or associated with an ACL-R(22.9%and 18%,P=0.47),or when comparing only BHTs associated with an ACL-R(23%and 27.7%,P=0.9)or not.When comparing cohorts before and after 2014,we found a significant decrease in the overall failure rate from 26%to 11%(P<0.03).Isolated lesions presented a decrease from 28%to 6.6%(P=0.02),BHTs from 34%to 8%(P=0.09)and those associated with an ACL-R from 25%to 10%(P=0.09).Mean RTS time was 6.5 mo in isolated lesions and 8.64 mo when associated with an ACL-R.Overall,56%of patients returned to the same sport activity level.Mean pre and postoperative Lysholm scores were 64 and 85(P=0.02),and IKDC 58 and 70(P=0.03).Out of 84 asymptomatic patients evaluated with MRI,39%were classified as“not healed”and 61%as“healed”.CONCLUSION Even though the overall failure rate of our series was 20.3%,we found a statistically significant decrease from 26%to 11%,not only for isolated lesions,but also for BHT’s and those associated with an ACL-R when comparing our series in two different cohorts,most probably due to improvements in surgical technique.

Buechel-Pappas Total Ankle Replacement: Use of Highly Cross-Linked Polyethylene Meniscal Bearings over a 13 - 15 Year Interval

Background: The Buechel-Pappas (BP) meniscal bearing total ankle replace-ment was initially developed as a “shallow-sulcus” talar component device using cobalt-chromium-molybdenum alloy, in 1978, and later, modified to a “deep-sulcus” talar component device using titanium nitride (TiN) ceramic and porous coating in 1989. Wear related osteolytic cysts were noted in the tibia and talus surrounding these devices that compromised long term fixation and stability when using standard ultra-high molecular weight polyethylene (UHMWPe) as a bearing material. This study explores the use of highly cross-linked UHMWPe (HXLPe) to minimize osteolysis by replacing standard UHMWPe with this more wear-resistant material. Methods: There were 12 primary and 8 revision total ankle replacements followed for 13 to 15 years. HXLPe was used in all meniscal bearings, either as primary or revision implants. All stable metallic tibial and talar components were retained in revision cases. Osteolytic cysts greater than 10 mm in diameter were bone grafted with homologous morselized banked bone through cortical windows in the tibia or talus. No adjuvant screw fixation was used to stabilize any metallic implant. Results: No HXLPe bearings failed in this study, and no re-revisions were performed. No primary total ankle replacement failed in this study, and there were no substantial osteolytic cysts (>2 mm) observed in primary total ankle replacements on plain X-rays. All bone grafted osteolytic cysts in revision ankle replacements remained stable, even though partial resorption of the grafted material was identified in most of the ankles. No loosening of porous coated and TiN coated tibial and talar components were seen;the longest surviving metal components in the revision group was 24 years with the revised bearing at 15 years. Conclusions: HXLPe has greatly improved wear resistance in meniscal-bearing BP total ankle replacements in both primary and revision arthroplasties. Osteolytic cysts can be successfully bone grafted during bearing exchange revisions. Primary and revision, cementless BP metallic total ankle components have remained well-fixed to bone in the long term (greater than 20 years), without the use of adjuvant screw fixation.

Evaluation of the Early Functional Outcome Following Arthroscopic Partial Meniscectomy for Meniscal Tears

Meniscal tears are among the common knee pathologies which affect activities of daily living if not managed properly. Arthroscopic knee surgery is an evolving procedure in our environment and patient satisfaction with this procedure needs to be evaluated. This was a prospective study carried out between June 2017 and May 2018 with the aim to determine the effectiveness of Arthroscopic Partial Meniscectomy in the management of meniscal tears in our environment. The Western Ontario Meniscal Evaluation Tool (WOMET) Knee Score was used to assess patient satisfaction with this procedure. A total of thirty-one patients were recruited into the study consisting of eighteen males and thirteen females with an average age of thirteen years (17 - 48 years) who underwent arthroscopic partial meniscectomy. Preoperative and postoperative knee scores at 6 weeks and 12 weeks were compared using the Western Ontario Meniscal Evaluation Tool. At the end of the study period, data collated were analyzed using the specified tools. In terms of clinical outcomes, arthroscopic partial meniscectomy showed statistically significant improvement of symptoms as evidenced by a mean knee score of 75.6 (SD 9.3) at 6 weeks, 87.7 (SD 4.7) at 12 weeks compared with a preoperative knee score of 46.7. Medial meniscal tears were more common than lateral meniscal tears in all age groups and both sexes recruited into the study. The most common type of meniscal tear seen was the longitudinal type of tear while complex tear is the least type of tear seen. The surgery (arthroscopic partial meniscectomy) is an evolving area of sports medicine that requires sub-specialization, however solves the problem of increased mobility following open surgery. This study will tend to add to existing knowledge as patients who are mostly sports inclined can return to play very early with better outcome scores as regards pain and function.

Treatment of meniscal tears: An evidence based approach

Treatment options for meniscal tears fall into three broad categories;non-operative,meniscectomy or meniscal repair.Selecting the most appropriate treatment for a given patient involves both patient factors(e.g.,age,co-morbidities and compliance)and tear characteristics(e.g.,location of tear/age/reducibility of tear).There is evidence suggesting that degenerative tears in older patients without mechanical symptoms can be effectively treated non-operatively with a structured physical therapy programme as a first line.Even if these patients later require meniscectomy they will still achieve similar functional outcomes than if they had initially been treated surgically.Partial meniscectomy is suitable for symptomatic tears not amenable to repair,and can still preserve meniscal function especially when the peripheral meniscal rim is intact.Meniscal repair shows 80%success at 2 years and is more suitable in younger patients with reducible tears that are peripheral(e.g.,nearer the capsular attachment)and horizontal or longitudinal in nature.However,careful patient selection and repair technique is required with good compliance to post-operative rehabilitation,which often consists of bracing and non-weight bearing for 4-6 wk.

Is traumatic meniscal lesion associated with acute fracture morphology changes of tibia plateau? A series of arthroscopic analysis of 67 patients

BACKGROUND Computed tomography(CT)has become a routine preoperative examination for tibial plateau fractures(TPFs).Assessing the location of the fragment and intercondylar eminence fracture can provide clinicians with valuable information;however,the evaluation of traumatic meniscal lesion(TML)and arthroscopic management are controversial.AIM To predict TML by three-dimensional skeletal anatomy changes in unilateral TPF and bilateral TPF on preoperative thin layer CT.METHODS Acute fracture of tibial plateau patients undergoing arthroscopic surgery between December 2017 and December 2019 were included in this retrospective study.The type,zone,and location of TMLs were diagnosed based on the operation records and/or arthroscopic videos.Measurement of three-dimensional fracture morphology included the following:Frontal fragment width of plateau,sagittal fragment subsiding distance(FSD),sagittal fracture line distance,sagittal posterior tibial slope,and transversal area ratio of fragment area)on preoperative CT three-dimensional plane.The correlation of TML with skeletal values was calculated according to unicondylar TPFs and bicondylar TPFs.RESULTS A total of 67 patients were enrolled in this study,among which 30 patients had TMLs,lateral/medial(23/7).FSD was a particularly positive factor to predict TML,with odds ratio of 2.31(1.26-5.63).On sagittal view of CT,FSD degree of 8 mm and posterior tibial slope exceeding 11.74°implied enhanced risk of TML in bicondylar TPFs.On coronal view,once fragment width of plateau surpassed 3 cm,incidence of TML reached 100%.On transverse view,area ratio of fragment as enhanced risk of 5.5%and FSD>4.3 mm for predicting TML were observed in unicondylar TPFs.CONCLUSION TML can be predicted by different parameters on preoperative CT views according to unicondylar fractures and bicondylar TPFs.

Natural History of Symptomatic Meniscal Tears: Arthroscopic Evaluation of Chondral Damage at 4-Year Minimum

Background: The natural history of meniscal tears is unclear. Studies have tried to clarify many aspects. Association with chondral injuries are of main relevance to the long-term status of the knee but evidence is limited. Objective: The aim of this study is to describe the intraarticular state of the knee focused on chondral injury in patients with persistent symptomatic meniscal tears that were untreated for a minimum period of 4 years. Methods: A total of 47 patients with symptomatic meniscal tears in whom surgery was indicated but was delayed mainly for administrative reasons, were recruited between January 1st, 2004 and April 30th, 2010 in a regional hospital. Follow up ended until circumstances allowed surgical resolution through arthroscopy. Only patients with meniscal tear in which diagnosis was confirmed and remained symptomatic were included. Patients with initial grade IV Kellgren-Lawrence osteo-arthritis were excluded. Statistical chi-square and logistic regression analysis were used. Results: Mean follow up period was 5.8 years (range: 4.3 - 10.2 years). 57 meniscal injuries were found in 47 patients. 25 were lateral and 32 medial meniscal tears. Overall, 29 patients had articular cartilage damage (51%). Chondral injuries were found in 15 of 25 lateral meniscal lesions (60%) and 14 of 32 medial lesions (44%). Patients with lateral compartment meniscal injury had a relative risk (RR) of 2.5 of developing chondral injury (p-value 0.05). Compared to 51% of patients with associated chondral and meniscal damage (n = 29), only 12% of patients with healthy meniscus (n = 7) had chondral injury (p-value 0.05). Conclusion: Persistent symptomatic meniscal tears after medium to long term (4 to 10 years) are associated with chondral damage in 51% of patients. Chondral damage associated with meniscal tears is usually deep and involves femur and tibial sides. Lateral menisci injury is significantly associated with articular cartilage damage in the ipsilateral compartment. This study demonstrates a significant association between meniscal injury and chondral damage.

Evaluation of Accuracy of Clinical Examination and MRI on Diagnosing Anterior Cruciate Ligament and Meniscal Tears in Comparison to Diagnostic Arthroscopy among Patients Attending at Muhimbili Orthopedic Institute

Routine use of Magnetic Resonance Imaging (MRI) as screening test after clinical diagnosis for meniscal and/or anterior cruciate ligament (ACL) has a detrimental effect on patients in limited resourced countries. This study was done to compare accuracy of clinical examination and that of (MRI) on diagnosing meniscal and or (ACL) tears. Methodology: A cross-sectional-descriptive study was done on 57 knees of patients. Clinical examination, MRI and then diagnostic arthroscopy, as the gold standard, were done to all the cases. Results were recorded;the accuracies of MRI and clinical examination were evaluated and their results were compared. Results: Median age of patients was 40 years. Clinical examination had sensitivity of 93.62% and specificity of 40% for diagnosing meniscal tears;and sensitivity of 100%;and specificity of 97.67% for diagnosing ACL tear. MRI had sensitivity of 85.11%, and specificity of 40% for meniscal tear diagnosis and 71% and 100% respectively for ACL tear diagnosis. Diagnostic accuracy was 84.21% for meniscal and 98.24% for ACL tears by clinical examination and by MRI was 77.19% and 92.98% respectively. Conclusion: Clinical examination has higher accuracy than MRI on diagnosing both ACL and meniscal tear. Thus patients may be scheduled for diagnostic and interventional arthroscopy if clinical examination reveals meniscal and or ACL injuries. MRI use should be reserved when clinical evaluation is inconclusive or cannot be done.

Discoid meniscus:Treatment considerations and updates

A discoid meniscus is a morphological abnormality wherein the meniscus loses its normal‘C’shape.Although most patients are asymptomatic,patients might still present with symptoms such as locking,pain,swelling,or giving way.Magnetic resonance imaging is usually needed for confirmation of diagnosis.Based on a constellation of factors,including clinical and radiological,different approaches are chosen for the management of discoid meniscus.The purpose of this review is to outline the treatment of discoid meniscus,starting from conservative approach,to the different surgical options for this condition.The PubMed and Google Scholar databases were used for this review.Studies discussing the treatment of discoid meniscus from 2018 to 2023 were searched.Initially there were 369 studies retrieved,and after removal of studies using the exclusion criteria,26 studies were included in this review.Factors such as stability,presence of tear,and morphology can help with surgical planning.Many approaches have been used to treat discoid meniscus,where the choice is tailored for each patient individually.Postoperatively,factors that may positively impact patient outcomes include male sex,body mass index<18.5,age at symptom onset<25 years,and duration of symptoms<24 months.The conventional approach is partial meniscectomy with or without repair;however,recently,there has been an increased emphasis on discoid-preserving techniques such as meniscoplasty,meniscopexy,and meniscal allograft transplantation.

Early graft failure after meniscus allograft transplantation： an unusual cause of using all-inside meniscal repair device

Meniscal allograft transplantation （MAT） may offer .an attractive alternative to restore the normal biomechanical structure of knees. The mean early failure rate （≤2 years） of MAT is approximately 10%.1-3 A successful outcome of MAT depends on the ligamentous stability of knee, limb alignment, graft types, and graft fixation methodsY Graft fixations include the meniscal horns and the peripheral rim. Techniques for fixation of the peripheral rim include sutures or a meniscal repair device such as FasT-Fix （Smith ＆ Nephew Inc, Andover, MA, USA）. Here we present an unusual case of early graft failure using FasT-Fix sutured to the peripheral rim of the graft.

Macroscopic and Histological Evaluations of Meniscal AIIograft Transplantation Using Gamma Irradiated Meniscus： A Comparative in Vivo Animal Study

Background：Many studies suggest that the gamma irradiation decreases allograft strength in a dose-dependent manner.However,no study has demonstrated that this decrease in strength translates into higher failure rate in meniscal allograft transplantation （MAT）.The aim of this study was to investigate the effects of gamma irradiation on macroscopic and histological alterations of transplanted meniscal tissue and joint cartilage after MAT.Methods：Medial total meniscectomies were performed on the right knees of 60 New Zealand white rabbits.All meniscal allografts were divided into three groups （20 in each group） and then sterilized with 0 Mrad,1.5 Mrad,or 2.5 Mrad of gamma irradiation.For each group,5 menisci were randomly chosen for scanning electron microscopic （SEM） analysis and the remaining 15 were prepared for MAT surgeries.Forty-five right knees received MAT surgeries （0 Mrad group,1.5 Mrad group,2.5 Mrad group,15 in each group）,whereas the remaining 15 only received medial meniscectomy （Meni group）.The left knees of the Meni group were chosen as the Sham group （n =15）.All the rabbits were sacrificed at week 24 postoperatively.Cartilage of the medial compartment of each group was evaluated macroscopically using the International Cartilage Repair Society （ICRS） score and then histologically using the Mankin score based on the Masson Trichrome staining.Results：The SEM analysis confirmed that the meniscal collagen fibers would be significantly damaged as the dose of gamma irradiation increased.At week 24,the overall scores of macroscopic evaluations of the transplanted meniscal tissue showed no significant differences among the three groups receiving MAT surgeries,except for 2 in the 2.5 Mrad group presented partial radial tears at midbody.The ICRS scores and the Mankin scores showed the lowest in the Sham group and the highest in the Meni group （P 〈 0.05）.For the three groups receiving MAT surgeries,the 2.5 Mrad group showed significant higher ICRS scores and Mankin scores than both the 0 Mrad group and the 1.5 Mrad group （P 〈 0.05）.Whereas the 1.5 Mrad group presented similar results to the 0 Mrad group concerning both the ICRS scores and the Mankin scores.Conclusions：The current in vivo animal study proved that although the meniscal collagen fibers were damaged after gamma irradiation,the failure rate of MAT surgeries might not significantly increase if the irradiation dose was 〈1.5 Mrad for New Zealand white rabbits.

Biosynthetic scaffolds for partial meniscal loss:A systematic review from animal models to clinical practice

Acute or degenerative meniscus tears are the most common knee lesions.Meniscectomy provides symptomatic relief and functional recovery only in the short-to mid-term follow-up but significantly increases the risk of osteoarthritis.For this reason,preserving the meniscus is key,although it remains a challenge.Allograft transplants present many disadvantages,so during the last 20 years preclinical and clinical research focused on developing and investigating meniscal scaffolds.The aim of this systematic review was to collect and evaluate all the available evidence on biosynthetic scaffolds for meniscus regeneration both in vivo and in clinical studies.Three databases were searched:46 in vivo preclinical studies and 30 clinical ones were found.Sixteen natural,15 synthetic,and 15 hybrid scaffolds were studied in vivo.Among them,only 2 were translated into clinic:the Collagen Meniscus Implant,used in 11 studies,and the polyurethane-based scaffold Actifit®,applied in 19 studies.Although positive outcomes were described in the short-to mid-term,the number of concurrent procedures and the lack of randomized trials are the major limitations of the available clinical literature.Few in vivo studies also combined the use of cells or growth factors,but these augmentation strategies have not been applied in the clinical practice yet.Current solutions offer a significant but incomplete clinical improvement,and the regeneration potential is still unsatisfactory.Building upon the overall positive results of these“old”technologies to address partial meniscal loss,further innovation is urgently needed in this field to provide patients better joint sparing treatment options.

Degenerative meniscus: Pathogenesis, diagnosis, and treatment options

The symptomatic degenerative meniscus continues to be a source of discomfort for a significant number of patients. With vascular penetration of less than onethird of the adult meniscus, healing potential in the setting of chronic degeneration remains low. Continued hoop and shear stresses upon the degenerative meniscus results in gross failure, often in the form of complex tears in the posterior horn and midbody. Patient history and physical examination are critical to determine the true source of pain, particularly with the significant incidence of simultaneous articular pathology. Joint line tenderness, a positive Mc Murray test, and mechanical catching or locking can be highly suggestive of a meniscal source of knee pain and dysfunction. Radiographs and magnetic resonance imaging are frequently utilized to examine for osteoarthritis and to verify the presence of meniscal tears, in addition to ruling out other sources of pain. Non-operative therapy focused on nonsteroidal anti-inflammatory drugs and physical therapy may be able to provide pain relief as well as improve mechanical function of the knee joint. For patients re-fractory to conservative therapy, arthroscopic partial meniscectomy can provide short-term gains regarding pain relief, especially when combined with an effective, regular physiotherapy program. Patients with clear mechanical symptoms and meniscal pathology may benefit from arthroscopic partial meniscectomy, but surgery is not a guaranteed success, especially with concomitant articular pathology. Ultimately, the long-term outcomes of either treatment arm provide similar results for most patients. Further study is needed regarding the short and long-term outcomes regarding conservative and surgical therapy, with a particular focus on the economic impact of treatment as well.

Surgical treatment for a combined anterior cruciate ligament and posterior cruciate ligament avulsion fracture: A case report

BACKGROUND Independent avulsion fractures with anterior cruciate ligament(ACL)or posterior cruciate ligament(PCL)attachment are relatively common among tibial intercondylar eminence fractures,and their postoperative outcomes are generally favorable.Conversely,huge avulsion fractures of the intercondylar eminence containing the attachment site of both the ACL and the PCL are extremely rare,and the reported clinical outcomes are poor.CASE SUMMARY We describe a 30-year-old Japanese male's huge avulsion fracture of the intercondylar eminence of a tibia containing the attachment site of both the ACL and PCL,together with a complete tear of the medial collateral ligament and a partial tear of both the medial and lateral menisci caused by a fall from a high place.All of these injuries were treated surgically,with anatomical reduction and stable fixation.The limb function at 1 year post-surgery was excellent(Lysholm score:100 points).CONCLUSION Although this patient's complete surgical repair was complex,it should be performed in similar cases for an excellent final clinical outcome.

Controversial role of arthroscopic meniscectomy of the knee: A review

The role of arthroscopic partial meniscectomy(APM) in reducing pain and improving function in patients with meniscal tears remains controversial. Five recent highquality randomized controlled trials(RCTs) compared non-operative management of meniscal tears to APM, with four showing no difference and one demonstrating superiority of APM. In this review, we examined the strengths and weaknesses of each of these RCTs, with particular attention to the occurrence of inadvertent biases. We also completed a quantitative analysis that compares treatment successes in each treatment arm, considering crossovers as treatment failures. Our analysis revealed that each study was an excellent attempt to compare APM with non-surgical treatment but suffered from selection, performance, detection, and/or transfer biases that reduce confidence in its conclusions. While the RCT remains the methodological gold standard for establishing treatment efficacy, the use of an RCT design does not in itself ensure internal or external validity. Furthermore, under our alternative analysis of treatment successes, two studies had significantly more treatment successes in the APM arm than the non-operative arm although original intention-totreat analyses showed no difference between these two groups. Crossovers remain an important problem in surgical trials with no perfect analytical solution. With the studies available at present, no conclusion can be drawn concerning the optimal treatment modality for meniscal tears. Further work that minimizes significant biases and crossovers and incorporates sub-group and cost-benefit analyses may clarify therapeutic indications.

Potential Association between Anterior Cruciate Ligament Tear and “Bi-Collateral” Ligamentous Rupture: A Retrospective Study

Background: Anterior cruciate ligament (ACL) tears are common complications of knee trauma. This entity can be reliably diagnosed by Magnetic Resonance Imaging. There is a lack of data on the epidemiology of ACL tears in Sub-Saharan Africa. The aim of this study is to describe the radiological aspects of post traumatic ACL tears in a black African setting (Yaounde Teaching Hospital). Methods: ninety six (96) MR studies of the knee were retrospectively reviewed. They were realized on a low field device (0.2T) from July 2012 to December 2013. All the examinations were indicated for knee trauma. Ligamentous, meniscal, bony and joint lesions were sought on coronal and sagittal sections. Results: the sample consists of 70% (68/96) of men. The mean age is 35.36 ± 11.86 years. The prevalence of ACL tears is 45.8% (44/96) of which 36 (81.81%, 36/44) are total tears. 23 (24%) have associated meniscal lesion and 8 (8.3%) have a simultaneous damage of the collateral ligaments. The most frequently injured part of the meniscus is its posterior horn (12/23 cases). Meniscal and “bi-collateral” ligament injuries are independently associated to ACL tears. Conclusion: The prevalence of ACL tears at the Yaounde Teaching Hospital is 45.8%. It is independently associated to meniscal tears and concomitant injury of the tibial and fibular collateral ligaments.

Taenidium barretti ichnofabric and rainfall seasonality:Insights into dryland suites of Scoyenia ichnofacies

The present work analyzes the monotypic Taenidium barretti ichnofabric developed in abandoned channels and floodplains to understand its paleoecological significance in highly seasonal fluvial systems.The data come from the Cretaceous paleosols of the Marília Formation(Bauru Basin,SE Brazil),in which the T.barretti ichnofabric and rhizoliths represent the biotic record.Beetle larvae are considered to be the most likely T.barretti tracemakers in these paleosols.The intensity and recurrence of bioturbation suggest that the windows of opportunity for beetle population growth were very short and controlled by the progressive substrate desiccation after flood cessation.The characteristics of the trace fossil assemblage suggest soil colonization by r-strategic organisms triggered by flooding events that provided the resource inputs necessary for their living during rainy seasons.The results also show that in fluvial systems with high discharge variations,the boundaries between a“pre-desiccation suite”and a“desiccation suite”in the Scoyenia ichnofacies can be diffuse due to the short duration of colonization windows and progressive terrestrialization of floodplains and channels.Therefore,the frequency of flooding events,the lowered water table,and the rapidity of substrate desiccation constrained colonization by other burrowers and may be considered as firstorder factors controlling the generation of a monotypic T.barretti ichnofabric.Thus,the monotypic Taenidium ichnofabric in the Scoyenia ichnofacies context is an ichnomarker of brief windows for colonization in highly seasonal environments.

Injectable ECM hydrogel for delivery of BMSCs enabled full-thickness meniscus repair in an orthotopic rat model

Meniscal injuries have poor intrinsic healing capability and are associated with the development of osteoarthritis.Decellularized meniscus extracellular matrix(mECM)has been suggested to be efficacious for the repair of meniscus defect.However,main efforts to date have been focused on the concentration,crosslinking density and anatomical region dependence of the mECM hydrogels on regulation of proliferation and differentiation of adult mesenchymal stem cells(MSCs)in vitro 2D or 3D culture.A systematic investigation and understanding of the effect of mECM on encapsulated MSCs response and integrative meniscus repair by in vivo rat subcutaneous implantation and orthotopic meniscus injury model will be highly valuable to explore its potential for clinical translation.In this study,we investigated the in situ delivery of rat BMSCs in an injectable mECM hydrogel to a meniscal defect in a SD rat model.Decellularized mECM retained essential proteoglycans and collagens,and significantly upregulated expression of fibrochondrogenic markers by BMSCs versus collagen hydrogel alone in vitro 3D cell culture.When applied to an orthotopic model of meniscal injury in SD rat,mECM is superior than collagen I scaffold in reduction of osteophyte formation and prevention of joint space narrowing and osteoarthritis development as evidenced by histology and micro-CT analysis.Taken together,these results indicate mECM hydrogel is a highly promising carrier to deliver MSCs for long-term repair of meniscus tissue,while preventing the development of osteoarthritis.