Treatment of Chondroblastoma of the Capital Femoral Epiphysis in Children Using a Cartilage Fenestration Approach Combined With Artificial Bone Implantation

BACKGROUND: Chondroblastoma of the capital femoral epiphysis (CHCFE) in children is a rare benign bone tumor that poses significant therapeutic challenges due to its unique anatomic location adjacent to the physeal plate and femoral head articular cartilage. This study aimed to evaluate the clinical efficacy and safety of a cartilage fenestration approach combined with artificial bone implantation for the treatment of CHCFE. METHODS: A retrospective analysis was conducted on 25 consecutive pediatric patients (14 boys and 11 girls; mean age, 10.5 y; range, 6 to 14 y) diagnosed with CHCFE and treated at our institution between January 2011 and October 2021. All patients underwent cartilage fenestration plus curettage and artificial bone (calcium sulfurphosphorus composite) implantation. Lesions were classified into 4 types based on anatomic involvement: medial (n=8), central (n=10), lateral (n=5), and medial-central (n=2). The mean follow-up duration was 67.5 months (range, 24 to 145 mo). Clinical outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) functional score, with recurrence, complications [eg, avascular necrosis (AVN), physeal premature closure], and radiologic findings recorded. RESULTS: All patients had open epiphyseal plates preoperatively. The mean MSTS score improved significantly from 18.56 preoperatively to 27.40 postoperatively (P<0.001). At final follow-up, only 1 case (4%) of tumor recurrence was observed, and no AVN of the femoral head was detected. Among 16 patients with preoperative physeal plate invasion, 7 (43.75%) developed mild-to-moderate proximal femoral epiphyseal premature closure, predominantly in the lateral lesion group. Multivariate analysis identified preoperative femoral head involvement location as the only independent factor affecting postoperative MSTS scores (P=0.026), with lateral involvement associated with the lowest functional scores (mean, 23.00) compared with medial (27.88), central (28.10), and medial-central (27.00) involvement. CONCLUSION: The cartilage fenestration approach combined with artificial bone implantation is a safe and effective minimally invasive treatment for CHCFE in children, offering thorough tumor clearance, significant functional improvement, and low rates of recurrence and AVN. However, lateral involvement of the femoral head indicates a relatively poor prognosis, requiring more meticulous surgical planning and postoperative rehabilitation to optimize outcomes. LEVEL OF EVIDENCE: Level IV-case series.