In adults with anterior cruciate ligament (ACL) tears, bone bruises on magnetic resonance imaging (MRI) scans provide insight into the underlying mechanism of injury. There is a paucity of literature that has investigated these relationships in children with ACL tears.
To examine and compare the number and location of bone bruises between contact and noncontact ACL tears in pediatric patients.
Cohort study; Level of evidence, 3.
Boys ≤14 years and girls ≤12 years of age who underwent primary ACL reconstruction surgery between 2018 and 2022 were identified at 3 separate institutions. Eligibility criteria required detailed documentation of the mechanism of injury and MRI performed within 30 days of the initial ACL tear. Patients with congenital lower extremity abnormalities, concomitant fractures, injuries to the posterolateral corner and/or posterior cruciate ligament, previous ipsilateral knee injuries or surgeries, or closed physes evident on MRI scans were excluded. Patients were stratified into 2 groups based on a contact or noncontact mechanism of injury. Preoperative MRI scans were retrospectively reviewed for the presence of bone bruises in the coronal and sagittal planes using fat-suppressed T2-weighted images and a grid-based mapping technique of the tibiofemoral joint.
A total of 109 patients were included, with 76 (69.7%) patients sustaining noncontact injuries and 33 (30.3%) patients sustaining contact injuries. There were no significant differences between the contact and noncontact groups in terms of age (11.8 ± 2.0 vs 12.4 ± 1.3 years; P = .12), male sex (90.9% vs 88.2%; P > .99), time from initial injury to MRI (10.3 ± 8.1 vs 10.4 ± 8.9 days; P = .84), the presence of a concomitant medial meniscus tear (18.2% vs 14.5%; P = .62) or lateral meniscus tear (69.7% vs 52.6%; P = .097), and sport-related injuries (82.9% vs 81.8%; P = .89). No significant differences were observed in the frequency of combined lateral tibiofemoral (lateral femoral condyle + lateral tibial plateau) bone bruises (87.9% contact vs 78.9% noncontact; P = .41) or combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau) bone bruises (54.5% contact vs 35.5% noncontact; P = .064). Patients with contact ACL tears were significantly more likely to have centrally located MFC bruising (odds ratio, 4.3; 95% CI, 1.6-11; P = .0038) and less likely to have bruising on the anterior aspect of the lateral tibial plateau (odds ratio, 0.27; 95% CI, 0.097-0.76; P = .013).
Children with contact ACL tears were 4 times more likely to present with centrally located MFC bone bruises on preoperative MRI scans compared with children who sustained noncontact ACL tears. Future studies should investigate the relationship between these bone bruise patterns and the potential risk of articular cartilage damage in pediatric patients with contact ACL tears.

Characterizing the ultimate tensile strength (UTS) of the meniscus is critical in studying knee damage and pathology. This study aims to determine the UTS of the meniscus with an emphasis on its heterogeneity and anisotropy. We performed tensile tests to failure on the menisci of six month old Yorkshire pigs at a low strain rate. Specimens from the anterior, middle and posterior regions of the meniscus were tested in the radial and circumferential directions. Then the UTS was obtained for each specimen and the data were analyzed statistically, leading to a comprehensive view of the variations in porcine meniscal strength. The middle region has the highest average strength in the circumferential (43.3 ± 4.7 MPa) and radial (12.6 ± 2.2 MPa) directions. This is followed by the anterior and posterior regions, which present similar average values (about 34.0MPa) in circumferential direction. The average strength of each region in the radial direction is approximately one-fourth to one-third of the value in the circumferential direction. This study is novel as it is the first work to focus on the experimental methods to investigate the heterogeneity and anisotropy only for porcine meniscus.

Background: Bucket-handle meniscal tears are mostly treated arthroscopically. However, there is no clear evidence as to whether the time to surgery impacts the outcome and whether or not lesions should be treated urgently. Methods: Sixty patients were interviewed about the current status of their knee with a mean follow-up of 6.1 years (SD = 3.5). Forty-one patients underwent meniscus repair, and fifteen patients received partial resections. The primary outcome was the rate of reoperation after meniscus repair. Secondary outcomes were pain at rest and during exercise, return to sports, and Tegner and Lysholm scores. Results: The average time to surgery was 14.4 days, with no significant impact of surgical timing on the rate of reoperation. Furthermore, no significant differences were found in pain levels, return to sports, or Tegner and Lysholm scores based on the timing of surgery. Conclusions: In our cohort, the time to surgery was not a prognostic factor for the reoperation rate or postoperative outcome in repairing bucket-handle meniscal tears. Therefore, arthroscopic repair should not be performed in an emergency setting but conducted after careful planning by experienced arthroscopy surgeons. Regarding the return to sports, postoperative factors such as rehabilitation protocols or surgical techniques could be more important than the time to surgery.

OBJECTIVE: The meniscal vascularization remains poorly documented, particularly its origin. The aim of this cadaveric study was to describe the origin of the arterial vascularization of the menisci.
METHODS: This is an anatomical study on human specimens. Twenty knees were used. The average age of the subjects was 82.7 years old (56-97). Ten knees were injected with latex-neoprene and ten knees were injected with colored gelatin mixed with India ink. The same protocol for dissection was used in all cases.
RESULTS: The meniscal vascularization is provided by the genicular arteries of the knee originating from the popliteal artery. The superior medial, superior lateral, inferior medial, inferior lateral, and middle genicular arteries had constant pathways. A second middle genicular artery was found in 55% of cases. The inferior lateral genicular artery ran alongside the meniscal\'s periphery. The inferior medial genicular artery followed the proximal tibial metaphysis. In all dissections, a previously undocumented small artery originated from under the middle genicular arteries. This artery remained extracapsular and followed the medial meniscal periphery. This artery has been named the \"medial capsulo-meniscal artery\". The genicular arteries formed an extensive peri-articular anastomotic vascularization for the menisci and thus referred to the \"peri-meniscal arterial archs\". The lateral peri-meniscal arch was predominantly supplied by the inferior lateral genicular artery, while the medial peri-meniscal arch was mainly supplied by the medial capsulo-meniscal artery.
CONCLUSIONS: The peri-meniscal arterial archs are a vascular complex formed by the genicular arteries of the knee and an artery not previously described: the \"capsulo-meniscal artery\". These archs have a constant presence but their formation and distribution is different between the medial and lateral menisci.

The semimembranosus muscle inserts into several tendons that are associated with some pathologies. Although ultrasound is useful for studying, diagnosing, and managing these pathologies, the correct interpretation of any images requires a clear knowledge of the related anatomical structures and the inter-related functions. We studied 38 cryopreserved non-paired knees from adult anatomical specimens and 4 non-paired knees from 29 to 38-week-old fetuses. The semimembranosus muscle and its tendons were located, observed, and injected under ultrasound guidance. The macroscopic anatomy was studied using dissection and anatomical cuts and the tendons were analyzed histologically. Measurements of muscle were taken 10 cm from the medial epicondyle and just before the tendon divided. The ultrasound facilitated the identification of the different divisions of the tendon of semimembranosus muscle and the rotation of the muscle and tendon from medial to posterior. An anatomical study confirmed this rotation and revealed an average width, thickness, and diameter of 38.29 mm, 14.36 mm, and 112.64 mm, respectively. Important relationships were observed between the divisions of the main tendons and the medial collateral ligament, the posterior side of the knee and popliteus muscle. This information can help to explain knee pathologies and facilitate rehabilitation after surgery.

UNASSIGNED: Satisfactory clinical results of meniscal allograft transplantation (MAT) have been reported in recent years. However, it remains unclear whether the clinical outcomes of MAT when combined with an osteotomy are inferior to those of isolated MAT.
UNASSIGNED: To compare the survival rates and clinical outcomes of patients who received isolated medial MAT with those of patients undergoing medial MAT combined with high tibial osteotomy (HTO).
UNASSIGNED: Cohort study; Level of evidence, 3.
UNASSIGNED: A total of 55 patients underwent arthroscopic medial MAT using the soft tissue technique and HTO (mean age, 41.3 ± 10.4 years; 9 female); after fuzzy case-control matching on demographics, 55 controls who underwent isolated medial MAT were also included. Survival analyses were performed using the Kaplan-Meier method with surgical failure, clinical failure (Lysholm score, <65), and reoperation as endpoints. Subjective clinical scores were collected preoperatively and at the final follow-up.
UNASSIGNED: The mean follow-up time was 5.4 years, up to 8 years. All outcomes significantly improved at the last follow-up (P < .001). No differences were identified between MAT and MAT + HTO groups preoperatively and at the last follow-up (P > .05). At the final follow-up, 8 of 55 (14.5%) of the MAT + HTO patients and 9 of 55 (16.4%) of the MAT patients had a Lysholm score <65 (P = .885). Overall, 90% of the patients declared they would repeat the surgery regardless of the combined procedure. Surgical failure was identified in 6 of 110 (5.5%) patients: 5 of 55 (9.1%) in the MAT + HTO group and 1 of 55 (1.8%) in the MAT group (P = .093). Clinical failure was identified in 19 of 110 (17.3%) patients: 11 of 55 (20%) in the MAT + HTO group and 8 of 55 (14.5%) in the MAT group (P = .447). A significantly lower survivorship from surgical failure was identified in the MAT + HTO group (hazard ratio, 5.1; P = .049), while no differences in survivorship from reoperation and clinical failure were identified (P > .05).
UNASSIGNED: Patients undergoing medial MAT + HTO showed similar clinical results to patients undergoing isolated medial MAT at midterm follow-up, and thus a surgically addressed malalignment does not represent a contraindication for medial MAT. However, the need for a concomitant HTO is associated with a slightly higher failure rate over time.

UNASSIGNED: Although several studies have noted that patients are routinely overprescribed opioids, few have reported usage after arthroscopic surgery.
UNASSIGNED: To determine opioid consumption and allocation for unused opioids after common arthroscopic surgeries.
UNASSIGNED: Case series; Level of evidence, 4.
UNASSIGNED: Patients between the ages of 15 and 40 years who were scheduled to undergo anterior cruciate ligament reconstruction (ACLR), labral repair of the hip or shoulder, meniscectomy, or meniscal repair were prospectively enrolled. Patients were prescribed either 5 mg hydrocodone-325 mg acetaminophen or 5 mg oxycodone-325 mg acetaminophen based on surgeon preference. Patients completed a daily opioid usage survey during the 2-week postoperative period. In addition, patients completed a survey on postoperative day 21 inquiring about continued opioid use and medication disposal, if applicable. Opioid medication consumption was converted to morphine milligram equivalents (MMEs).
UNASSIGNED: Of the 200 patients who were enrolled in the study, 176 patients had sufficient follow-up after undergoing 85 (48%) ACLR, 26 (14.8%) hip labral repair, 34 (19.3%) shoulder labral repair, 18 (10.2%) meniscectomy, and 13 (7.4%) meniscal repair procedures. Mean age was 26.1 years (SD, 7.38); surgeons prescribed a mean of 26.6 pills whereas patients reported consuming a mean of 15.5 pills. The mean MME consumption in the 14 days after each procedure was calculated: ACLR (95.7; 44% of prescription), hip labral repair (84.8; 37%), shoulder labral repair (57.2; 35%), meniscectomy (18.4; 27%), and meniscal repair (32.1; 42%). This corresponded to approximately 39% of the total opioid prescription being utilized across all procedures. Mean MME consumption was greatest on postoperative day 1 in hip, shoulder, and meniscal procedures and on postoperative day 2 in ACLR. Only 7.04% of patients reported continued opioid use in the third postoperative week. Patients had a mean of 11 unused pills or 77.7 MMEs remaining. Of the patients with remaining medication, 24.7% intended to keep their medication for future use.
UNASSIGNED: The results of our study indicate that patients who undergo the aforementioned arthroscopic procedures consume <75 MMEs in the 2-week postoperative period, translating into a mean of 10 to 15 pills consumed. Approximately 60% of total opioids prescribed went unused, and one-fourth of patients intended to keep their remaining medication for future usage. We have provided general prescribing guidelines and recommend that surgeons carefully consider customizing their opioid prescriptions on the basis of procedure site to balance optimal postoperative analgesia with avoidance of dissemination of excess opioids.

UNASSIGNED: The goal was to determine the thickness and width of the knee joint meniscus at their different regions. The objective was to compare the dimensions at these regions and over the right- and left-sided specimens.
UNASSIGNED: The present study included 50 adult cadaveric knee joints, and 100 menisci (50 medial menisci and 50 lateral menisci) were studied. The meniscus was distributed into anterior, middle and posterior parts. Thickness and width at the mid-point of these three parts were determined by using the Vernier caliper.
UNASSIGNED: The breadth of the medial meniscus was 8.38 ± 1.64 mm, 7.68 ± 1.92 mm and 13.93 ± 2.69 mm at the anterior, middle and posterior one-third regions. Same measurements for the lateral menisci at these regions were 9.84 ± 1.78 mm, 8.82 ± 2.01 mm and 10.18 ± 2.23 mm, respectively. The thickness of the medial meniscus was 4.49 ± 0.78 mm, 4.07 ± 0.81 mm and 4.79 ± 0.93 mm at these regions. The lateral meniscus thickness was 3.82 ± 0.69 mm, 4.43 ± 0.98 mm and 4.36 ± 0.8 mm, respectively.
UNASSIGNED: It is believed that this data is enlightening to the arthroscopic surgeon during the meniscus transplantation either by using synthetic material or allograft as the proper sizing of the meniscus is important to prevent complications due to inaccurate sizing.

OBJECTIVE: The purpose of the present study was to perform a survey administered to members of the Meniscus International Network (MenIN) Study Group, seeking to delineate the most contentious aspects of meniscal extrusion classification and provide a foundation for new, more comprehensive definitions and treatments for these pathologies.
METHODS: MenIN Study Group is a group of international experts treating and performing research on meniscus pathology and treatment. All MenIN Study Group members were asked to complete a survey aimed at establishing criteria for the optimal classification system for meniscal extrusion. Data obtained from the completed questionnaires were transferred into a spreadsheet and then analysed. All responses are presented as counts, percentages or means.
RESULTS: Forty-seven (85.5%) MenIN Study Group members completed the survey and were included in this analysis. Key aspects recommended for inclusion in a comprehensive classification system for meniscal extrusion included laterality (93.6%), anatomical location (76.6%), patient age (76.6%), body mass index (BMI) (68.1%) and aetiology (68.1%). For classifying meniscal extrusion, 53.2% considered the distance in millimetres from the tibial plateau\'s outer margin as the most reliable measurement technique on imaging. Preferences for imaging modalities varied, with 44.7% favouring weight-bearing magnetic resonance imaging (MRI) and 36.2% opting for weight-bearing ultrasound due to its greater availability. Respondents advocated for a classification system addressing stability or progression of meniscal extrusion (66%), reducibility (53.2%), potential progression of knee osteoarthritis (OA) (83%), influencing treatment approaches (83%), a gradation system (83%), consideration of dynamic factors (66%), association with clinical outcomes and prognosis (76.6%) and investigation around centralization procedures (57.4%).
CONCLUSIONS: In conclusion, the findings of this survey shed light on the global perspectives regarding meniscal extrusion classification. It was generally felt that a new classification of extrusion measured on MRI scans at the mid-tibial plateau should be developed, which considers factors such as laterality, anatomical location, age, BMI and aetiology. Additionally, the results support the integration of dynamic factors and clinical outcomes in MRI-based classifications to inform treatment approaches.
METHODS: Level IV.

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.
CONCLUSIONS: 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.