Is the Greulich and Pyle Bone Atlas Suitable When Measuring Bone Age for Pediatric ACL Reconstruction in the Modern...

A reliable measure of bone age is of critical importance when planning anterior cruciate ligament reconstruction (ACLR) in a pediatric population. The Greulich and Pyle (G&P) method is still the most common method for bone age determination; however, it is based on radiographs from healthy Caucasian children of high socioeconomic status (SES) in Cleveland, Ohio, in the 1920s to 1940s and may not reflect the modern diverse United States population. The aim of our study was therefore to assess the degree of agreement between chronological age and bone age measured using G&P and further investigate whether there are any systematic differences across race, ethnicity, or SES.

This was a retrospective subanalysis of PLUTO (Pediatric ACL: Understanding Treatment Options), a prospective multicenter cohort study investigating outcomes in pediatric ACLR. All patients with bone age scores using the G&P method preoperatively were included. Data on race, ethnicity, biological sex, BMI, and SES [using a composite marker known as the area deprivation index (ADI)] were collected. Bland-Altman analysis was used to assess the agreement between chronological-measured and G&P-measured age. Systematic bias was defined as a significant mean difference between chronological-measured and G&P-measured age and was determined using Student t test for the cohort and within strata; and differences across strata were determined using a one-way ANOVA. P -values across strata were adjusted using the method of Benjamini and Hochberg to control the false discovery rate.

A total of 472 patients were included in the final analysis. Chronological age at evaluation was lower than the determined bone age for the cohort with a systematic bias of 2.9 months (SD, 12.8) ( P <0.001). The Bland-Altman 95% limits of agreement between bone age and chronological age were ∼2 years. There was significant variation in agreement in those aged 11 to 12 ( P <0.001), 13 ( P =0.008), and 15 years ( P =0.008). Female patients had a 3.9-month greater bias compared with males ( P =0.003). Underweight patients exhibited nearly 15.9 months lower bone age versus chronological age ( P =0.008). No systematic biases were detected across ethnicity ( P =0.21), race (0.13), or ADI index quartiles ( P =0.23).

Our study supports the continued use of G&P for bone age assessment across different racial, ethnic, and sociodemographic groups, with no significant differences detected across these strata. The observed ∼2-year limits of agreement between G&P bone age and chronological age reinforce the importance of skeletal age assessment in this cohort, particularly during the peripubertal period where large differences between chronological and skeletal age can exist. Systematic biases were found in certain age strata, between sexes, and in patients with low BMI. Clinicians should be aware of these variations and consider using multiple methods of assessing skeletal maturity when making growth-sensitive clinical decisions.

Level III-retrospective cohort.