Lower Extremity Growth according to AI Automated Femorotibial Length Measurement on Slot-Scanning Radiographs in Pediatric Patients.

Background Commonly used pediatric lower extremity growth standards are based on small, dated data sets. Artificial intelligence (AI) enables creation of updated growth standards. Purpose To train an AI model using standing slot-scanning radiographs in a racially diverse data set of pediatric patients to measure lower extremity length and to compare expected growth curves derived using AI measurements to those of the conventional Anderson-Green method. Materials and Methods This retrospective study included pediatric patients aged 0-21 years who underwent at least two slot-scanning radiographs in routine clinical care between August 2015 and February 2022. A Mask Region-based Convolutional Neural Network was trained to segment the femur and tibia on radiographs and measure total leg, femoral, and tibial length; accuracy was assessed with mean absolute error. AI measurements were used to create quantile polynomial regression femoral and tibial growth curves, which were compared with the growth curves of the Anderson-Green method for coverage based on the central 90% of the estimated growth distribution. Results In total, 1874 examinations in 523 patients (mean age, 12.7 years ± 2.8 [SD]; 349 female patients) were included; 40% of patients self-identified as White and not Hispanic or Latino, and the remaining 60% self-identified as belonging to a different racial or ethnic group. The AI measurement training, validation, and internal test sets included 114, 25, and 64 examinations, respectively. The mean absolute errors of AI measurements of the femur, tibia, and lower extremity in the test data set were 0.25, 0.27, and 0.33 cm, respectively. All 1874 examinations were used to generate growth curves. AI growth curves more accurately represented lower extremity growth in an external test set (n = 154 examinations) than the Anderson-Green method (90% coverage probability: 86.7% [95% CI: 82.9, 90.5] for AI model vs 73.4% [95% CI: 68.4, 78.3] for Anderson-Green method; χ2 test, P < .001). Conclusion Lower extremity growth curves derived from AI measurements on standing slot-scanning radiographs from a diverse pediatric data set enabled more accurate prediction of pediatric growth. © RSNA, 2024 Supplemental material is available for this article.

Does An Osteotomy Performed in Congenital Pseudarthrosis of the Tibia Heal?

BACKGROUND: Shortening and deformity of the tibia commonly occur during the treatment of congenital pseudarthrosis of the tibia (CPT). The role of osteotomies in lengthening and deformity correction remains controversial in CPT. This study evaluates the approach to and outcome after osteotomy performed in CPT. METHODS: We performed an IRB approved retrospective review of consecutive patients with CPT treated at our institution from 2010 through 2019. Patients who underwent osteotomies were included in this study. RESULTS: Nine patients (10 osteotomies-5 proximal metaphyseal and 5 diaphyseal) with a median age at osteotomy of 8.9 years (range: 4 to 21 y) were included. Six patients had neurofibromatosis-1, 1 had cleidocranial dysplasia, and 2 patients had idiopathic CPT. Four osteotomies were performed for deformity correction, 3 osteotomies to allow intramedullary instrumentation, and 3 osteotomies for lengthening. Five osteotomies were preceded by zolendronate treatment before surgery. Nine were fixed with a rod supplemented with external fixation (7) or locking plates (2). One osteotomy was stabilized with locked intramedullary nailing alone. Four osteotomies were supplemented with autologous bone graft, and bone morphogenic protein-2 was utilized in 3 osteotomies. Median time to healing was 222.5 days (range: 124 to 323 d). One osteotomy (locked intramedullary nailing) required grafting at 5.5 months and then healed uneventfully. Median healing index for patients undergoing lengthening was 57.9 days/cm (range: 35 to 81 d/cm). All 3 osteotomies performed for lengthening required a second osteotomy for preconsolidation at a mean of 34 days. Other complications included compartment syndrome requiring fasciotomy (n=2), tibial osteomyelitis (n=1), and fracture distal to cross-union (n=1). CONCLUSIONS: Contrary to much of the established practice, osteotomies may be safely performed in CPT for various indications. All osteotomies healed with only 1 osteotomy requiring secondary bone grafting. Although time to healing of the osteotomy was generally prolonged, this study suggests, somewhat surprisingly, that preconsolidation can occur frequently in lengthening procedures. LEVEL OF EVIDENCE: Level IV-case series.

Pediatric and Adolescent T-type Distal Humerus Fractures.

Although fractures of the elbow are extremely common in pediatric patients, the T-type distal humerus fracture is rare and offers unique challenges. The mechanism of injury may be similar to the adult counterpart and is usually caused by a fall onto a flexed elbow or from a direct blow. Diagnosing these injuries may be difficult. They often resemble extension-type supracondylar fractures, yet the treatment algorithm is quite different. In younger patients, percutaneous pinning remains a viable option, but for older adolescents, open reduction and internal fixation provides stable fixation at the elbow and the most reliable restoration of the articular surface. Appropriate imaging, careful radiographic diagnosis, and choice of surgical technique are of paramount importance when treating young patients with this injury. Most pediatric and adolescent patients with T-type distal humerus fractures have results better than those of adults but often worse than other elbow fractures in this age group.