The lateral epiphyseal vessels have not previously been rigorously defined. Methods: Twenty-two cadaveric capital femoral epiphyses from donors who had been three to seventeen years of age were analyzed and then digitized with use of a high-resolution laser scanner. The height, location, and approximate surface area of the epiphyseal tubercle were measured and were normalized to the size of the entire capital femoral epiphysis. Results: In all specimens except that from the youngest donor, the foramina for the lateral epiphyseal vessels were visible and were located directly superior to the epiphyseal tubercle. The height of the epiphyseal tubercle was 4.4 ± 1.1 mm. When normalized to the overall size of the capital femoral epiphysis, the relative height (r = 0.71) and relative area (r = 0.56) of the epiphyseal tubercle decreased with increasing age. The epiphyseal tubercle was consistently located in the posterosuperior quadrant, with its position being more posterior and less superior in specimens from younger donors. Conclusions: The epiphyseal tubercle appears to be a major stabilizer, or keystone, of the capital femoral epiphysis and the lateral epiphyseal vessels. Its relative decrease in height and surface area with increasing age may help explain the susceptibility of individuals to SCFE in adolescence: in a stable SCFE, the physis rotates on the tubercle; however, in an unstable SCFE, the tubercle dislodges, leading to more substantial displacement of the capital femoral epiphysis and the lateral epiphyseal vessels, risking osteonecrosis. Clinical Relevance: These anatomic data offer a possible insight into the pathogenesis of SCFE and the potential complication of osteonecrosis. When fixation of an SCFE is performed with a single screw, the posterosuperior quadrant should be avoided to maximize any possible derotational effect of the epiphyseal tubercle....

Background: Tibial torsion and femoral anteversion are common rotational abnormalities in children, and their courses are most often benign and self-resolving. Although neither usually requires surgical treatment, the decision to perform a derotational osteotomy is usually based on the degree of functional impairment. Neither condition is thought to influence the development of osteoarthritis of the hip or knee; however, to date there have been no large scale studies confirming this. Methods: Tibial torsion and femoral version in 1158 cadaveric tibiae and femora were measured using a camera setup based on previously described radiographic landmarks. Any specimens with obvious traumatic, rheumatic, or metabolic abnormalities were excluded. Degenerative joint disease of the hip and knee were each graded from 0 to 6. Correlations between tibial torsion, femoral version, age, race, and sex with osteoarthritis of the hip and knee joints were evaluated with multiple regression analysis. Results: The mean and SDs of tibial torsion and femoral anteversion were 7.9±8.8 and 11.4±12.0 degrees, respectively. African Americans had significantly increased tibial torsion (5.1±8.7 vs. 9.2±8.5 degrees, P<0.0005) and greater femoral anteversion (14.1±11.9 vs. 10.2±11.8 degrees, P0.05 for all). Discussion: This study confirmed previously reported differences in the rotational profiles between races and sexes. However, neither tibial torsion nor femoral anteversion had a significant influence on the development of arthritis of the hip or knee. Clinical Relevance: These results support the practice of treating tibial torsion and femoral anteversion based on the symptomatology of the patient. Parents of asymptomatic children can be reassured that long-term consequences are unlikely.

Background: The anatomy of the undulating distal femoral physis may be relevant to growth disturbance after physeal fractures and screw fixation about the physis. The surface anatomy of this physis has not been well described. Methods: We performed an anatomic study on 26 cadaveric distal femoral epiphyses in specimens 3 to 18 years of age. High-resolution 3-dimensional surface scans were obtained and analyzed to determine the heights, approximate surface areas, and locations of the major undulations. Results: Gross examination revealed lateral and anteromedial peripheral notches at the metaphyseal-epiphyseal junction, which deepen with advancing skeletal maturity. Within the epiphysis, there are 3 major undulations: a central ridge, lateral ridge, and medial peak, with mean heights of 5.5 mm (range, 2.9 to 9.8 mm), 2.5 mm (1.0 to 5.7 mm), and 2.9 mm (0.9 to 4.7 mm), respectively. The normalized height and surface area of each undulation decreased with increasing age, most dramatically in the central ridge. With respect to a line connecting the medial and lateral aspects of the physis, we found that the central peak passes more superior with younger age, and tends to be more posteriorly located. The lowest point of the physis is located either anteromedial or posterolateral. Conclusions: The central ridge, lateral ridge, and medial peak are the 3 major undulations in the distal femoral physis. The central ridge has the greatest height and most dramatic decrease in relative size with increasing age, suggesting structural importance. This anatomic data can guide metaphyseal and epiphyseal screw fixation. Clinical Relevance: This study provides quantitative data on the topographic anatomy of the distal femoral physis, which can guide screw placement about the physis. These data may help identify fractures patterns with a greater risk of growth disturbance and key radiographic landmarks for guiding fracture reduction.

Background: The ability to estimate skeletal maturity using a knee radiograph would be useful in anterior cruciate ligament (ACL) injuries and limb-length discrepancy in immature patients. Currently, a quick, accurate, and reproducible method is lacking. Methods: Serial knee radiographs made 3 years before to 2 years following the chronologic age associated with 90% of final height (an enhanced skeletal maturity gold standard compared with peak height velocity) were analyzed in 78 children. The Pyle and Hoerr (PH) knee method was simplified by developing discrete stages for the distal part of the femur, the proximal part of the tibia, the proximal part of the fibula, and the patella. The Roche-Wainer-Thissen (RWT) knee method was simplified from the 36 original parameters to 14 parameters by removing parameters that were poorly defined, were not relevant to the peripubertal age range, were poorly correlated with 90% final height, or were poorly reliable on a 20-radiograph pilot analysis. We also compared the recently described central peak value (CPV) of the distal part of the femur. The Greulich and Pyle (GP) left-hand bone age was included for comparison. Results: In this study, 326 left knee radiographs from 41 girls (age range, 7 to 15 years) and 37 boys (age range, 9 to 17 years) were included. Stepwise linear regression showed higher correlation in predicting years from 90% final height using the modified RWT and demographic characteristics (R² = 0.921) compared with demographic characteristics alone (R² = 0.840), CPV and demographic characteristics (R² = 0.866), GP and demographic characteristics (R² = 0.899), and PH and demographic characteristics (R² = 0.902). Seven parameters were excluded from the RWT and demographic characteristics model using stepwise linear regression and generalized estimating equations analysis, leaving 7 parameters (2 femoral, 4 tibial, and 1 fibular) in the final model. Compared with RWT and demographic characteristics (R² = 0.921), there were minimal incremental increases by adding CPV (R² = 0.921), GP (R² = 0.925), or PH (R² = 0.931). Conclusions: This large analysis of knee skeletal maturity systems isolated 7 discrete radiographic knee parameters that theoretically outperform the GP bone age in estimating skeletal maturity. Clinical Relevance: We present a modified knee skeletal maturity system that can potentially preclude the need for additional imaging of the hand and wrist in reliably estimating skeletal maturity.