Biomechanical characteristics of the meniscocapsular junction of the posterior segment of the medial meniscus.

PURPOSE: Despite extensive literature available on the mechanical properties of knee ligaments and menisci, research on the mechanical properties of the meniscus-capsular junction (MCJ) is lacking. This study aims to investigate the biomechanical behavior of the MCJ of the medial meniscus using a tensile failure test. MATERIALS AND METHODS: Seven dissected cadaveric knees were used for biomechanical analysis. Tensile failure tests were performed using an INSTRON ElectroPuls E1000 stress system to measure stress/strain curves, maximum load at failure, elastic limit load, elongation at break, elongation at the elastic limit, and linear stiffness, were collected and analyzed. RESULTS: All ruptures occurred at the MCJ. The MCJ displayed similar mechanical properties to knee ligaments. Average values were: maximum load at failure (63.9 ± 3.2 N), yield load (52.9 N ± 2.6 N), elongation at break (2.5 mm ± 0.3 mm), elongation at the elastic limit (1.25 mm ± 0.15 mm), strain at break (47.0% ± 3.5%), strain at yield (23.2% ± 2.3%), and stiffness (56.6 ± 9. N/mm-1). CONCLUSION: The meniscus-capsular junction's mechanical properties are similar to other knee ligaments and may play a role in knee stability. The findings provide insights into the the behavior of the meniscus-capsular junction could have clinical implications for diagnosing and surgical treatment of meniscocapsular lesions.

Construction and validation of a functional diagnostic score in anterior cruciate ligament ruptures of the knee in the immediate post-traumatic period. Preliminary results of a multicenter prospective study.

INTRODUCTION: Knee ligament injuries are frequent and their number is constantly increasing with the development of sports activities. Dynamic knee maneuvers usually make it possible to diagnose anterior cruciate ligament (ACL) injuries but they remain difficult to perform in the early post-traumatic phase. This leads to the almost systematic use of MRI scans, many of which turn out to be superfluous. The aim of this study was to construct a screening score based solely on history-taking, in order to help diagnose ACL injuries, and to define thresholds that could help inform recommendations for MRI usage. The hypothesis was that this score could distinguish a population of patients with a ruptured ACL from a population of patients with other knee injuries. MATERIAL AND METHODS: This prospective multicenter study included 166 patients. Patients were included if they were between 18 and 55 years of age, with knee trauma that had occurred in the last 10 days, and without a bone fracture on standard radiographs. They were excluded if the trauma required immediate surgical management and if they had a history of knee trauma. The screening score was completed by the physician. The score included the following items: assessment of pain, immediate post-traumatic functional impairment, notion of a "pop", feeling of instability and presence of a swelling. An MRI was systematically performed and the patient consulted a referring physician to compare the initial score with the diagnosis. RESULTS: Eighty-six patients had an injured ACL and 80 had a healthy ACL. Two thresholds could be identified. For a score lower than 4, the risk of an ACL injury was low with a sensitivity of 96% and a negative predictive value of 87%. For a score above 8, the ACL injury was highly probable with a specificity of 88% and a positive predictive value of 83%. DISCUSSION/CONCLUSION: The score was able to distinguish a population of patients with a ruptured ACL from a population of patients with other knee injuries. These preliminary results confirm that the selected items are relevant and that the score can help improve the diagnostic orientation of patients with recent knee trauma. Increasing the sample size in combination with an analysis of influencing factors will determine whether the performance of this score can be refined. LEVEL OF EVIDENCE: II prospective multicenter study.

ACTIfit™: 38% full resorption at 8 years in a cohort of 18 cases.

BACKGROUND: Preserving meniscal tissue is a major priority in young, physically active patients. Extensive meniscal defects may result in exercise pain and premature osteoarthritis. ACTIfit™ is a synthetic meniscal substitute that may improve short-term functional scores via biological integration with meniscal tissue regeneration. However, long-term data on the lifespan and chondroprotective effect of this newly formed tissue are lacking. The primary objective of this study was to assess the biological integration of ACTIfit™ based on magnetic resonance imaging (MRI) findings. The secondary objective was to evaluate long-term clinical outcomes. HYPOTHESIS: The ACTIfit™ meniscal substitute undergoes biological integration over time, suggesting chondroprotective potential. MATERIALS AND METHODS: A 2014 report by Baynat et al. described the 2-year clinical and radiological outcomes of 18 patients after ACTIfit™ implantation at the Clermont-Tonnerre military teaching hospital (Brest, France). The patients had chronic knee pain of at least 6 months' duration after failure of primary meniscal surgery with segmental meniscal defects. Mean age was 34.0±7.9 years. A concomitant procedure was performed in 13 (60%) patients, including osteotomy in 8 and ligament reconstruction in 5. For the current study, the clinical and radiological follow-up was at least 8 years. Assessments were with the Genovese grading scale for substitute morphology on MRI scans, International Cartilage Research Society (ICRS) score for osteoarthritis progression, and Lysholm score for clinical outcome. Failure was defined as total substitute resorption (Genovese morphology grade 1) or revision surgery with implant removal, conversion to meniscus allografting, or arthroplasty. RESULTS: MRI scans were available for 12 (66%) patients. The reason for not having long-term MRI scans was surgery for substitute removal or arthroplasty in 3 of the remaining 6 patients. Complete implant resorption (Genovese grade 1) was noted in 7/12 (58%) patients and osteoarthritis progression to ICRS grade 3 in 4/12 (33%) patients. At last follow-up, the mean Lysholm score was significantly improved vs. baseline (79±15 vs. 55±13, P=0.005). CONCLUSION: The frequency of complete ACTIfit™ resorption 8 years after implantation was high. This finding argues against ability of this substitute to induce the regeneration of durable meniscal tissue with a chondroprotective effect. The clinical outcome score was significantly improved at last follow-up. However, no conclusions can be drawn regarding the effectiveness of ACTIfit™ given the high frequency of concomitant surgical procedures. LEVEL OF EVIDENCE: IV, retrospective observational cohort.

The SFA datalake platform and anterior cruciate ligament tear registry of the French Society of Arthroscopy (SFA): Rationale, statutes and plans.

SFA Datalake is the registry platform of the French Society of Arthroscopy (SFA). It was designed to collect and store data on arthroscopic orthopedic surgery and joint-sparing surgery in French-speaking countries. The anterior cruciate ligament (ACL) tear registry is the first registry to be set up based on SFA Datalake. Registries are intended to enable systematic standardized data collection, and provide information for surgeons to improve clinical practice and results. The ACL tear registry was designed in the light of guidelines, the literature and existing registries. Data are collected prospectively on a secure on-line application accessible via a computer or smartphone. Data collection is organized according to clinical examination results, preoperative findings, and follow-up data based on patient-administered subjective quality of life questionnaires. The pilot committee consists of 5 SFA board members, appointed for 2 years. LEVEL OF EVIDENCE: IV.

Consensus statement on data to be entered in the ACL tear registry: SFA-DataLake.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction is a frequent procedure, with room for improvement by rehabilitation measures and associated peripheral and meniscal surgeries that are currently under assessment, requiring follow-up. Outside France, there have been ACL registries for 20 years now. The French Arthroscopy Society (SFA) decided to set up an ACL tear registry within its SFA DataLake registry platform. MATERIAL AND METHOD: This article presents the methodology underlying the ACL Tear Registry: i.e., identification, definition and coding of essential and relevant data. A test phase comprised an initial assessment to improve data quality and overall coherence, to optimize data-entry time for patients and practitioners, who are the guarantors of the registry's use and efficacy. RESULTS: The SFA DataLake ACL Tear Registry was made available to SFA members in December 2021. It aims to enable a review of practices for surgeons, early detection of failure of procedures and implants, with rates of failure and abnormal complications, and identification of prognostic factors for outcome, especially regarding original items that do not figure in previous registries. CONCLUSION: SFA DataLake strikes a balance between "indispensable" and "original" items. The choice of contents and data quality is founded on a robust methodology with overall coherence, enabling analysis of large cohorts and comparisons with the literature and other registries. However, it remains to assess rates of data entry and item relevance as the Registry progresses. LEVEL OF EVIDENCE: IV.

The hamstrings are more impacted than the quadriceps after severe ankle sprain.

Ankle sprains (AS) are common in the military population, with a prevalence 5 to 8 times higher than that for civilians. The aim of this study was to evaluate in patients with severe AS the impact of disuse on thigh muscle induced by unloading and immobilization due to care. This study focused on muscle trophicity and dynamometric strength. In this observational prospective study, assessments were repeated at 3 visits: close to injury, 15 and 30 days following the sprain. The injured limb was compared to the contralateral limb. A dynamometer assessment was used to monitor changes in strength and fatigue of the thigh muscles of both limbs. Isometric and isokinetic concentric evaluation of peak torque (PTiso and PTdyn), total work (Wt), and peak torque time integral (IPT) of thigh muscles. Full follow-up was obtained in 30 subjects. The injured limbs showed significant deficits in the mean (SD). The quadriceps PTiso and IPT deficits were -12.6% ± 1.9% (P < .0001) and -13.27% ± 1.8% (P < .0001), respectively. The quadriceps PTdyn showed a significant deficit since V2 (-12.2.5% ± 2.0). The quadriceps Wt presented a significant deficit of -4.2% ± 2.4 (P < .0007) at 1 month. The hamstring PTdyn deficit presented a mean loss of -16.5% ± 2.4% (P < .0001). The hamstring Wt deficit was -13.7% ± 2.3% (P < .001). The analysis of variance showed that the grade of the sprain had a significant effect on the quadriceps PTq deficit (P < .016) but not the type of discharge. Our study showed that disuse leads to a significant deficit in the strength of knee muscles within 1 month. It is noteworthy that the hamstrings are more affected than the quadriceps. The rehabilitation protocol to prevent the risk of iterative ankle injuries and secondary knee injuries should incorporate early training of both quadriceps and hamstrings.

Ramp Lesions of the Posterior Segment of the Medial Meniscus: What Is Repaired? A Qualitative Histological Study of the Meniscocapsular and Meniscotibial Attachments.

BACKGROUND: Lesions of the posterior segment of the medial meniscus are the most common intraarticular lesions associated with ACL injuries. Ramp lesions are tears in the peripheral attachment of the posterior horn of the medial meniscus. Such injuries are difficult to detect on preoperative MRI. Arthroscopically, the prevalence of these lesions can reach 24%. Anatomical descriptions of the posterior horn of the medial meniscus are becoming clearer, however, histological descriptions are lacking, especially with regard to the presence or absence of capillaries. QUESTIONS/PURPOSES: The present qualitative histologic study focused on the posterior segment of the medial meniscus and the meniscocapsular and meniscotibial junctions. Specifically, the objective of this study was to analyze the posterior segment of the medial meniscus and the meniscosynovial junction and to determine whether the meniscus tibial ligament exists. METHODS: We dissected 10 unpaired cadaveric knees (five male, five female, age range 55 to 66 years), five left and five right, from the French "Don du corps" body donation program via a posterior approach to the posteromedial capsule. We excluded specimens with intra-articular abnormalities (ACL rupture, meniscal tear, arthrosis) preceding dissection by arthrotomy. We thus accessed the posterior segment of the medial meniscus and the meniscosynovial junction. The proximal capsule, posterior segment of the medial meniscus, entire meniscal capsular-tibial junction, and a fragment of the tibia were removed en bloc. For each knee, three sagittal spaced sections of the posterior segment of the medial meniscus (Zone 4 as defined by Smigielski) were performed. Two experienced pathologists performed qualitative histological analysis on the 30 samples after Hematoxylin and eosin staining, and Safranin O staining. RESULTS: Macroscopically, the meniscotibial attachments were pellucid and homogeneous, as were the meniscocapsular attachments; however, the meniscocapsular attachments appeared to be denser in both the anterior and posterior regions of the capsule. Microscopy of the meniscosynovial junction revealed loose collagen fibers that were partially oriented but not parallel, a cellular network featuring a few fibroblasts and adipocytes, and several capillaries. No between-attachment histologic differences were apparent; both tissues shared a site of attachment to the posterior horn of the medial meniscus. We did not detect the meniscotibial ligament, macroscopically or microscopically. CONCLUSIONS: A ramp lesion may not be a ligamentous injury because the meniscotibial ligament was not detected. Rather, it appears that a ramp lesion is a tear in the common attachment point between the posterior horn of the medial meniscus and meniscocapsular and meniscotibial junctions. This structure is vascularized, and contains nonoriented low cellularity collagen of moderate density. CLINICAL RELEVANCE: Based on our results, a better rationale for the recommendation of surgical repair of a ramp appears to be needed, given the absence of a meniscotibial ligament, and the presence of capillaries in the meniscocapsular and meniscotibial attachments.

Excellent outcomes for lateral unicompartmental knee arthroplasty: Multicenter 268-case series at 5 to 23 years' follow-up.

INTRODUCTION: Isolated lateral compartment osteoarthritis of the knee (LCOA) is 10 times less frequent than medial compartment involvement. Long-term assessments of unicompartmental knee arthroplasty (UKA) in this indication are rare, with small series. HYPOTHESIS: Survival and functional outcome of lateral UKA in a large series are quite acceptable; the strategy is suited for isolated LCOA. MATERIAL AND METHOD: A multicenter retrospective study in 6 French health establishments included all lateral UKAs performed between January 1988 and September 2014. Clinical data (range of motion, International Knee Society (IKS) knee and function scores, satisfaction), paraclinical data (radiologic angles) and complications were prospectively entered in medical files during follow-up and analyzed retrospectively at end of follow-up. RESULTS: During the study period, 311 lateral UKAs were performed in 295 patients, using 5 fixed-bearing implant models. Twenty-eight patients died within 5 years, and 15 (4.8%) were lost to follow-up. The series thus comprised 268 lateral UKAs in 63 male and 205 female patients, with a mean age of 68.8±10.5 years, including 7 cases of post-traumatic osteoarthritis and 4 of aseptic osteonecrosis. Mean follow-up was 9.1 years (range, 5-23 years), implant survivorship with failure defined as all-cause revision surgery was 85.4% at 10 years and 79.4% at 20 years. At last follow-up, IKS knee score was 87.0 and IKS function score 80.2. Maximal flexion was 125°. 94.3% of patients were satisfied or very satisfied. The main cause of revision surgery was osteoarthritis in another knee compartment (66,7%, n=26). CONCLUSION: Lateral UKA showed good survivorship, comparable to medial UKA, with good functional results and excellent long-term satisfaction. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Hidden lesions of the posterior horn of the medial meniscus: a systematic arthroscopic exploration of the concealed portion of the knee.

BACKGROUND: Anterior cruciate ligament (ACL) tears are frequently associated with meniscal lesions. Despite improvements in meniscal repair techniques, failure rates remain significant, especially for the posterior horn of the medial meniscus. PURPOSE: To determine whether a systematic arthroscopic exploration of the posterior horn of the medial meniscus with an additional posteromedial portal is useful to identify otherwise unrecognized lesions. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: In a consecutive series of 302 ACL reconstructions, a systematic arthroscopic exploration of the posterior horn of the medial meniscus was performed. The first stage of the exploration was achieved through anterior visualization via a standard anterolateral portal. In the second stage, the posterior horn of the medial meniscus was visualized posteriorly via the anterolateral portal with the scope positioned deep in the notch. In the third stage, the posterior horn was probed through an additional posteromedial portal. A χ2 test and logistic regression analysis were performed to determine if the time from injury to surgery was associated with the meniscal tear pattern. RESULTS: A medial meniscal tear was diagnosed in 125 of the 302 patients (41.4%). Seventy-five lesions (60%) located in the meniscal body were diagnosed at the first stage of the arthroscopic exploration. Fifty lesions located in the ramp area were diagnosed: 29 (23.2%) at the second stage and 21 lesions (16.8%) at the third stage after minimal debridement of the superficial soft tissue layer. The latter type of lesion is called a "hidden lesion." Altogether, the prevalence of ramp lesions in this population was 40%. Meniscal body lesions (odds ratio, 2.6; 95% confidence interval, 1.18-5.18; P < .02) were found to be significantly correlated with a longer delay between injury and surgery. CONCLUSION: Posterior visualization and posteromedial probing of the posterior horn of the medial meniscus can help in discovering a higher rate of lesions that could be easily missed through a standard anterior exploration. In numerous cases, these lesions were "hidden" under a membrane-like tissue and were discovered after minimal debridement through a posteromedial portal.

[Progress in surgery of limb's wounds during the Great War]. / L'evolution de la chirurgie des plaies de guerre des membres en 1914-1918.

The prominent tenets of limb's wound surgery have been improved during the Great War. Before 1914, traditional treatment of war injuries was usually applied on the ground because injuries caused by firearms were supposedly trivial while the threatening infection refrained surgeons from acting. From the very start of 1914, gangrene and septicaemia were the terrible consequences of new types of injuries provoked by shrapnel, all the more dangerous that the wounded men were numerous and the injuries were nursed after a too important delay. New surgical facilities have been organised by the French Military Health Service which created the "Ambulances Chirurgicales Automobiles", improved the selection procedures and the mobilization of many surgeons. New surgical treatments such as lancing, continuous use irrigation, delayed suture of wounds allowed improvement of results and saved more than one soldier. Finally, the excision of dead and contaminated tissues is still nowadays the most important progress in war surgery.