Chondroblastoma and chondromyxoid fibroma are benign but locally aggressive bone tumors. Chondroblastoma, a destructive lesion with a thin radiodense border, is usually seen in the epiphysis of long bones. Chondromyxoid fibroma presents as a bigger, lucent, loculated lesion with a sharp sclerotic margin in the metaphysis of long bones. Although uncommon, these tumors can be challenging to manage. They share similarities in pathology that could be related to their histogenic similarity. Very rarely, chondroblastoma may lead to lung metastases; however, the mechanism is not well understood.

Lateral pinning is preferable to cross pinning for fixation of pediatric supracondylar humerus fractures as a result of decreased risk of ulnar nerve injury.

Perthes disease is an osteonecrosis of the femoral epiphysis with unclear etiology. This study aimed to systematically review the association between genetic determinants of hypercoagulability (Factor V Leiden, prothrombin II, and methylenetetrahydrofolate reductase; MTHFR) and Perthes disease. PubMed and Scopus searched from inception to January 2012, data extraction and quality assessment were performed. The odds ratio (OR) for the allele effect was pooled, and heterogeneity and publication bias were assessed. Twelve case-control studies met inclusion criteria and had sufficient data for extraction. There were 824 cases and 2,033 controls with a mean age range of 6.1-14.7 years. The prevalence of the minor allele in controls was 0.015 (95% confidence interval (CI): 0.008, 0.023), 0.012 (95% CI: 0.008, 0.017), and 0.105 (95% CI: 0.044, 0.167) for factor V Leiden, prothrombin II, and MTHFR, respectively. The factor V Leiden allele increased the risk of Perthes with a pooled OR of 3.10 (95% CI: 1.68, 5.72), while prothrombin II and MTHFR had non-significantly pooled OR 1.48 (95% CI: 0.71, 3.08), and 0.97 (95% CI: 0.72, 1.30), respectively. The factor V Leiden mutation is significantly related to Perthes disease, and its screening in at-risk children might be useful in the future.