Changes in Functional Meniscal Morphology During Skeletal Growth and Maturation.

Background: Little is known on how meniscal morphology develops during skeletal growth and maturation and its subsequent relationship with the corresponding bony anatomy. Hypotheses: (1) Meniscal dimensions and morphology would change by age during skeletal growth and maturation in different ways in boys compared with girls. (2) Morphological features of the medial and lateral menisci would correlate to medial and lateral femoral condyle curvatures. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Anatomic features of the medial and lateral menisci were measured on magnetic resonance imaging scans from 269 unique knees (age, 3-18 years; 51% female) with no prior history of injury, congenital or growth-related skeletal disorders, or bony deformities. Morphological shape-based measurements were normalized to tibial plateau width or determined as ratios of meniscal dimensions. The association between age and anatomy was analyzed with linear regression. Two-way analysis of variance with the Holm-Sídák post hoc method was used to compare anatomy between sexes in different age groups. Linear regression was used to evaluate the relationship between femoral condyle curvature radius and meniscal morphology in each compartment after adjusting for age and sex. Results: Meniscal length, width, horn distance, mean cross-sectional area (CSA), and mean height increased with age in both sexes (R2 > 0.1; P < .001). Age-related changes in meniscal morphology were seen in normalized length, width, horn distance, and mean height; width-to-length ratio; horn distance-to-length ratio (lateral meniscus only); normalized mean CSA (except lateral meniscus in girls); and mean tip angle (R2 > 0.04; P < .02). Sex-based differences were also found, with some morphological differences (normalized length and height) throughout development (P < .03) and size differences (length, width, and mean CSA) in later development (P < .01). After adjusting for age and sex, there were significant correlations between medial condyle curvature radius and normalized width, width-to-length ratio, horn distance, horn distance-to-length ratio, mean CSA, and mean height of the medial meniscus (P≤ .041) and between lateral condyle curvature radius and normalized length, mean height, and mean tip angle of the lateral meniscus (P≤ .004). Conclusion: Age-related changes in meniscal dimensions and morphology, most notably a nonuniform growth pattern in meniscal geometry, occurred during skeletal growth and maturation, with different trends in boys than in girls.

Comparison of Size of Posterior Tibial Slope and Medial Tibial Depth in Patients With an Isolated Meniscal Tear Requiring Surgery and Matched Uninjured Controls.

BACKGROUND: Meniscal injuries are extremely common. Several anatomic features of the knee, including the tibial plateau morphology, have been shown to influence knee biomechanics and the risk of ligamentous injuries. Little is known, however, how these morphological features influence the risk of isolated meniscal injuries in the anterior cruciate ligament (ACL)-intact knee. HYPOTHESIS: There are differences in the slopes and concavity of the tibial plateau between patients with isolated meniscal tears and matched uninjured controls. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: In total, 89 patients with first-instance isolated medial (n = 37) or lateral (n = 52) meniscal injuries requiring surgical treatment (mean age, 16 ± 1 years; 35% female) were matched to 89 controls with uninjured knees and no previous injuries (mean age, 16 ± 2 years; 35% female) based on age and sex. Magnetic resonance imaging scans (preoperative for injured group) were used to measure the coronal slope of the tibial plateau, posterior slope of the medial and lateral tibial plateaus, and maximum depth of the medial tibial plateau. General linear models were used to evaluate the differences in tibial plateau morphology between the knees with and without meniscal injuries, with and without adjustment for age and sex. RESULTS: Compared with matched controls, patients with surgically treated isolated meniscal tears had a smaller lateral tibial slope (by 2.2° [medial meniscal injury] and 1.6° [lateral meniscal injury]; P < .02), a smaller medial tibial slope (by 2.3° [medial meniscal injury] and 2.4° [lateral meniscal injury]; P < .001) and a larger medial tibial depth (by 0.8 mm [medial meniscal injury] and 0.9 mm [lateral meniscal injury]; P < .001). There were no differences in coronal tibial slope between the injured and uninjured groups. There were no differences in quantified anatomic features between the isolated medial and lateral meniscal injury groups. The same trends were observed after adjusting for age and sex. CONCLUSION: This study suggests that patients with an isolated meniscal tear requiring surgery have a smaller posterior tibial slope and a larger medial tibial depth (more concave medial tibial plateau) than matched uninjured controls. This is contrary to what is known for ACL tears, in which a steeper posterior tibial slope and a shallower medial tibial depth have been associated with an increased risk of ACL tear.

Variation in management of pediatric post-traumatic urine leaks.

PURPOSE: High-grade pediatric renal trauma may be associated with a urine leak and appropriate management remains unclear. METHOD: Data on patients with a traumatic renal injury were retrieved from the trauma registry and data warehouse of a pediatric level 1 trauma center over a 15-year period. Demographics, diagnoses, imaging, interventions performed, and follow-up information on patients with a urine leak were analyzed. RESULTS: 187 renal injuries were identified and 32 (17%) were high grade. There were 21 (11%) diagnoses of urine leak, comprising the study population. Leaks were identified 0-10 day post-injury. All patients underwent initial computerized tomography (CT); however, 10 (48%) lacked excretory-phase imaging, leading to repeat CT. Ten patients (48%) did not undergo an intervention for their leak, and 11 (52%) underwent at least one, most commonly stent placement (10). Comparing non-intervention and intervention groups: Injury Severity Score (ISS) and initial Shock Index - Pediatric Adjusted (SIPA) were similar, but there was variation in antibiotic prophylaxis (60% vs 100%), average number of imaging studies performed (6.4 vs 8.1) and average length of hospital stay in days (7.7 vs 8.6). CONCLUSION: Traumatic urine leaks are unusual, and half require no intervention. Management is variable and the development of care guidelines could decrease variation. Given their infrequency a multi-institutional study is required to generate sufficient patient volume.

Earlier Resolution of Symptoms and Return of Function After Bridge-Enhanced Anterior Cruciate Ligament Repair As Compared With Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Bridge-enhanced anterior cruciate ligament repair (BEAR) has noninferior patient-reported outcomes when compared with autograft anterior cruciate ligament reconstruction (ACLR) at 2 years. However, the comparison of BEAR and autograft ACLR at earlier time points-including important outcomes such as resolution of knee pain and symptoms, recovery of strength, and return to sport-has not yet been reported. HYPOTHESIS: It was hypothesized that the BEAR group would have higher outcomes on the International Knee Documentation Committee and Knee injury and Osteoarthritis Outcome Score, as well as improved muscle strength, in the early postoperative period. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 100 patients aged 13 to 35 years with complete midsubstance anterior cruciate ligament injuries were randomized to receive a suture repair augmented with an extracellular matrix implant (n = 65) or an autograft ACLR (n = 35). Outcomes were assessed at time points up to 2 years postoperatively. Mixed-model repeated-measures analyses were used to compare BEAR and ACLR outcomes. Patients were unblinded after their 2-year visit. RESULTS: Repeated-measures testing revealed a significant effect of group on the International Knee Documentation Committee Subjective Score (P = .015), most pronounced at 6 months after surgery (BEAR = 86 points vs ACLR = 78 points; P = .001). There was a significant effect of group on the Knee injury and Osteoarthritis Outcome Score-Symptoms subscale scores (P = .010), largely attributed to the higher BEAR scores at the 1-year postoperative time point (88 vs 82; P = .009). The effect of group on hamstring strength was significant in the repeated-measures analysis (P < .001), as well as at all postoperative time points (P < .001 for all comparisons). At 1 year after surgery, approximately 88% of the patients in the BEAR group and 76% of the ACLR group had been cleared for return to sport (P = .261). CONCLUSION: Patients undergoing the BEAR procedure had earlier resolution of symptoms and increased satisfaction about their knee function, as well as improved resolution of hamstring muscle strength throughout the 2-year follow-up period. REGISTRATION: NCT02664545 (ClinicalTrials.gov identifier).

ACL Size, but Not Signal Intensity, Is Influenced by Sex, Body Size, and Knee Anatomy.

BACKGROUND: Little is known about sex-based differences in anterior cruciate ligament (ACL) tissue quality in vivo or the association of ACL size (ie, volume) and tissue quality (ie, normalized signal intensity on magnetic resonance imaging [MRI]) with knee anatomy. HYPOTHESIS: We hypothesized that (1) women have smaller ACLs and greater ACL normalized signal intensity compared with men, and (2) ACL size and normalized signal intensity are associated with age, activity levels, body mass index (BMI), bicondylar width, intercondylar notch width, and posterior slope of the lateral tibial plateau. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Knee MRI scans of 108 unique ACL-intact knees (19.7 ± 5.5 years, 62 women) were used to quantify the ACL signal intensity (normalized to cortical bone), ligament volume, mean cross-sectional area, and length. Independent t tests were used to compare the MRI-based ACL parameters between sexes. Univariate and multivariate linear regression analyses were used to investigate the associations between normalized signal intensity and size with age, activity levels, BMI, bicondylar width, notch width, and posterior slope of the lateral tibial plateau. RESULTS: Compared with men, women had significantly smaller mean ACL volume (men vs women: 2028 ± 472 vs 1591 ± 405 mm3), cross-sectional area (49.4 ± 9.6 vs 41.5 ± 8.6 mm2), and length (40.8 ± 2.8 vs 38.1 ± 3.1 mm) (P < .001 for all), even after adjusting for BMI and bicondylar width. There was no difference in MRI signal intensity between men and women (1.15 ± 0.24 vs 1.12 ± 0.24, respectively; P = .555). BMI, bicondylar width, and intercondylar notch width were independently associated with a larger ACL (R 2 > 0.16, P < .001). Younger age and steeper lateral tibial slope were independently associated with shorter ACL length (R 2 > 0.03, P < .04). The combination of BMI and bicondylar width was predictive of ACL volume and mean cross-sectional area (R 2 < 0.3). The combination of BMI, bicondylar width, and lateral tibial slope was predictive of ACL length (R 2 = 0.39). Neither quantified patient characteristics nor anatomic variables were associated with signal intensity. CONCLUSION: Men had larger ACLs compared with women even after adjusting for BMI and knee size (bicondylar width). No sex difference was observed in signal intensity, suggesting no difference in tissue quality. The association of the intercondylar notch width and lateral tibial slope with ACL size suggests that the influence of these anatomic features on ACL injury risk may be partially explained by their effect on ACL size. REGISTRATION: NCT02292004 and NCT02664545 (ClinicalTrials.gov identifier).