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 Śmigielski) 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.

Objectives Coronavirus disease-19 (COVID-19) has spread worldwide and poses various challenges to healthcare services. The limited supply of medical and personal-protective equipment has affected the ability of many countries to respond to the crisis. Three-dimensional printing (3DP) is well suited to addressing these shortages. We assessed the medical role of 3DP during the COVID-19 outbreak in hospitals in France. Design Retrospective survey. Setting and intervention We included and questioned all French level-1 and -2 COVID-certified centers. Participants One hundred and thirty-eight COVID-certified centers were contacted across France: 38 (27.5 %) level 1 and 100 (72.5 %) level 2 centers. The analysis focused on 133 centers (96.37 %), among which 98 (73.68 %) used 3DP. Main outcome measures The primary endpoint was the number of pieces printed in 3D. The secondary endpoints were the mode, type, and benefits of 3DP. Results The total number of pieces printed in 3D nationwide was 84,886: 76,000 pieces of individual protective equipment (IPE) (89.53 %), 6335 pieces of biomedical equipment (7.47 %), and 2551 prototypes (3.01 %). In 91 cases (92.85 %), 3DP was performed using external printers. The pieces 3D-printed by the various centers helped around 6109 patients and protected around 41,091 caregivers. Conclusions 3DP produced more than 84,000 pieces at 98 centers, helped more than 6000 patients, and protected more than 41,000 caregivers. Therefore, 3DP played a major role in medical aid during the COVID-19 outbreak in France.

Highlights The first use of laparoscopy to treat pelvic ring fractures: a case report. We describe the first use of laparoscopy to treat pelvic ring fracture. This “laparoscopic internal fixation” delivered an in situ result as good as that of open surgery. Despite a long operating time, the blood loss was very low. This technique opens a new approach to treatment of pelvic fractures.