RESUMO
BACKGROUND: The treatment of pediatric anterior cruciate ligament (ACL) injuries is controversial, and no clear management guidelines have been established. PURPOSE: To evaluate the association between elapsed time from ACL injury to surgery and the incidence of meniscal tears and chondral injuries in patients aged ≤16 years. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between December 2012 and April 2019, a total of 207 consecutive knees in 207 patients aged ≤16 years underwent primary ACL reconstruction and were included in this study. Patients were divided into 1 of 2 groups (early group [≤150 days] and delayed group [>150 days]) based on the time between injury and surgery. Patient records, including arthroscopic findings identified by 2 experienced knee surgeons at the time of surgery, were reviewed for demographic information, incidence and types of medial and lateral meniscal tears, and chondral injuries and their locations in each group. RESULTS: There were 180 knees in the early group and 27 knees in the delayed group. The delayed group showed a significantly higher rate of medial meniscal tears than the early group: 16 of 27 (59.2%) and 46 of 180 (25.6%), respectively (odds ratio [OR], 4.24 [95% CI, 1.83-9.33]; P = .0011). The delayed group had a significantly lower rate of lateral meniscal tears than the early group: 6 of 27 (22.2%) and 90 of 180 (50.0%), respectively (OR, 0.29 [95% CI, 0.11-0.70]; P = .007). The delayed group had significantly higher rates of chondral injuries in the medial femoral condyle and the medial tibial plateau than the early group: 8 of 27 (29.6%) and 25 of 180 (13.9%), respectively (OR, 2.61 [95% CI, 1.03-6.62]; P = .049), and 2 of 27 (7.4%) and 1 of 180 (0.6%), respectively (OR, 14.32 [95% CI, 1.58-208.10]; P = .045). CONCLUSION: Delayed ACL reconstruction was associated with an increased incidence of medial chondral injuries and medial meniscal tears but with a decreased incidence of lateral meniscal tears.
RESUMO
The feature of osteoconductivity, and expression of inductive BMP and transcription factors (Runx2 and Osterix) for osteoblast differentiation, which was related to conductive bone formation, were observed in experimentally created defects in rat femoral and parietal bones filled with beta-tricalcium phosphate (beta-TCP) or carbonate apatite (CAP). Femoral cortical bone defects were repaired by conductive bone formed by osteoblasts differentiated around beta-TCP and CAP, and immunohistochemical observation revealed that the osteoblasts expressed BMPs, Runx2, and Osterix. However, the repair in parietal bone defects was incomplete despite the beta-TCP and CAP filling. Only cells, which differentiated around beta-TCP or CAP, and formed conductive bone expressed BMPs, Runx2, and Osterix. These findings revealed that the osteoconductivity of calcium phosphate materials required the expression of BMPs as the prerequisite for Runx2 and Osterix expression. Therefore, it is suggested that when calcium phosphate ceramics are used as bone substitute materials, BMPs are essential for osteoconductivity.
