Anterior cruciate ligament tear patterns in young patients: An arthroscopic multicenter study.

INTRODUCTION: In the last decade, there has been a renewed interest in anterior cruciate ligament (ACL) preservation surgeries in the younger patients. Several ACL preservation techniques such as primary repair, augmented repair, and scaffold repair have been described based on the particular tear type and pattern. The purpose of this study was to determine the distribution of tear patterns in young patients presenting with an acute ACL injury. METHODS: A prospective observational study was performed at two tertiary children's hospitals. Patients under 18 years undergoing ACL reconstruction within 8 weeks of initial injury were included from 2017 to 2019. Tear patterns were classified by two orthopedic surgeons from each of the two centers during arthroscopic ACL reconstruction into 4 types: I. Avulsion off the femur, II. <10% of total ACL length tear from femoral end, III. Mid-substance tear and IV. Single bundle tear. For reliability, the four surgeons classified ACL injury (2 rounds each) based on de-identified intraoperative videos of 33 randomly selected surgical ACL cases. Inter and intra-rater reliability studies were calculated using Kappa statistics. RESULTS: 224 patients (123 males, 101 females) with mean age of 16 (range: 9-18) years were enrolled in this study. Fifty-seven (25%) patients reported contact injury while 167 (75%) reported non-contact. Isolated ACL injury was recorded in 70 (31%) patients, while concomitant injuries were recorded in 154 patients (69%). The most common associated injury was lateral meniscus tear (35%), followed by lateral and medial meniscus tears (20%). According to our classification, 31 (14%) patients were Type I, 30 (13%) were Type II, 139 (62%) were Type III, 18 (8%) were Type IV. The intra-rater reliability was excellent for 2 reviewers, good for 1 and marginal for another. The overall inter-rater reliability for all 4 reviewers was marginal for both readings. There was no statistical difference in the occurrence of type of tear based on the mechanism of injury (contact vs non-contact) or age of the patients. CONCLUSIONS: This is the first multicenter study using an arthroscopic assessment to classify the location of ACL tear in the young population. It gives us further insight on the possible application for surgeries to preserve the ACL in this group. Larger studies incorporating these findings with MRI evaluation and ACL repair techniques are needed to confirm the utility of this information to decide the eligibility for repair in pediatric patients.

MRI in idiopathic, stable, slipped capital femoral epiphysis: evaluation of contralateral pre-slip.

PURPOSE: Early diagnosis and treatment of slipped capital femoral epiphysis (SCFE) is important to prevent slip progression and avoid complications. We sought to determine if MRI findings in patients with unilateral SCFE could indicate 'pre-slip' or predict future SCFE in the contralateral hip. METHODS: A prospective study evaluated patients with unilateral SCFE over a two-year period. MRI of the asymptomatic hip was performed within the perioperative period. Patients were followed with radiographs until a contralateral slip occurred or until physeal closure. Demographics, clinical stability, severity, posterior slope angle (PSA), modified Oxford Bone Score (mOBS) and patency of the triradiate cartilage were recorded and statistical analysis performed. RESULTS: In all, 33 of 54 patients with unilateral SCFE were enrolled into the study. In all, 29 (87.8%) had complete follow-up. Five of the enrolled patients (15.2%) developed a sequential slip requiring in situ pinning. Six of 33 (18.2%) patients had positive MRI findings: four of which proceeded to sequential SCFE and two which did not. One sequential slip had a negative MRI. PSA predicted 1/11 sequential slips (sensitivity 9.09%, specificity 81.4%, positive predictive value (PPV) 11.1%, negative predictive value (NPV) 77.8%) and mOBS predicted 5/11 sequential slips (sensitivity 45.5%, specificity 93%, PPV 62.5%, NPV 87%). An open triradiate cartilage was present in 8/11 patients with sequential slips (sensitivity 72.7%, specificity 81.4%, PPV 50%, NPV 92.1%). CONCLUSION: MRI findings consistent with 'pre-slip' were present in 66.7% of patients who developed a sequential SCFE. Further study on the utility/sensitivity of MRI in predicting sequential SCFE is warranted. LEVEL OF EVIDENCE: II, diagnostic.

Treatment of chronic, stable slipped capital femoral epiphysis via surgical hip dislocation with combined osteochondroplasty and Imhauser osteotomy.

PURPOSE: Treatment of slipped capital femoral epiphysis (SCFE), including the modified Dunn procedure, restores anatomy with significant risk for avascular necrosis (AVN), if performed in the setting of moderate to severe, stable SCFE. The Imhauser osteotomy has been shown to be an effective way to correct residual deformity without the risk of AVN. We sought to evaluate the effectiveness and safety of a combined Imhauser osteotomy and osteochondroplasty, performed via a surgical hip dislocation approach for the acute and delayed treatment of stable SCFE. METHODS: A retrospective review was performed on a series of patients who underwent Imhauser osteotomy and osteochondroplasty via surgical hip dislocation for treatment of chronic, stable SCFE. Patients were divided into acute or delayed treatment groups based on whether osteotomy was performed as the initial slip treatment. RESULTS: In total 19 patients (15 male, four female, average age 13.7 years) were reviewed. Six osteotomies were performed acutely in combination with in situ pinning, 13 were delayed at least six months after in situ pinning (average 21.7 months). Two hips had labral tears that required repair. The mean follow-up was 61 months (23 to 120) (delayed) and 53 months (27 to 61) (acute). The average improvement in slip angle was 40.7° (delayed) and 50.2° (acute) (p = 0.0916), final post-operative slip angle averaged 15.8° (delayed) and 17.8° (acute) (p = 0.544). Femoral neck length and greater trochanteric height were similar between both groups. Average alpha angle at final follow-up measured 55.8° (delayed) and 60.8° (acute) (p = 0.542). No cases of AVN were identified. CONCLUSION: Imhauser osteotomy combined with osteochondroplasty via surgical hip dislocation approach is a safe and effective treatment of moderate to severe, stable SCFE performed in both the acute and delayed setting.