Summary

ACL reconstruction in the adolescent population: Utilizing anthropometric data to predict 4-stranded hamstring autograft size

Abstract

Objectives

Anterior cruciate ligament (ACL) injury is increasingly common in the active adolescent population. There are various graft options available for ACL reconstruction. Due to its favorable biomechanical strength and reliable clinical outcomes, the 4-stranded hamstring autograft is a popular choice. Smaller graft sizes (less than 7.0mm in diameter) have been documented to have poorer outcomes. This study seeks to investigate the role of anthropometric data in the prediction of 4-stranded hamstring autograft size in an adolescent population.

Methods

This was a cohort study involving 68 patients who underwent a single-bundle ACL reconstruction with a 4-stranded hamstring autograft (Gracilis and Semi-Tendinosus). Pre-operative data such as age, gender, height, weight, body mass index (BMI) and body surface area (BSA) were recorded. Intra-operatively, the diameter of the 4-stranded hamstring graft was recorded. Multiple regression analysis was used to determine the correlation between anthropometric data and the diameter of the hamstring autograft.

Results

There were 36 females and 32 males recruited. The mean age of the females and males was 14.9 years (+/- 1.1) and 15.2 years (+/- 0.9) respectively. Males had a significantly (p < 0.05) larger graft size compared to females. There was a moderate correlation between graft diameter and height and weight in females. There was a moderate correlation between graft diameter and weight in males. BMI did not correlate with graft diameter in females but had a moderate correlation (r = 0.38) in males. BSA had a moderate correlation with graft diameter in both females (r = 0.40) and males (r = 0.39).

The following regression equation was obtained for females:

Graft Diameter = 2.7572*height + 0.0025*weight + 2.3470 (R2=0.246, p =0.01)

The following regression equation was obtained for males:

Graft Diameter = 0.014*weight + 6.843 (R2=0.161, p = 0.02)

Conclusion

There is a positive correlation between anthropometric data and hamstring graft diameter in the adolescent population. This will allow surgeons to perform improved pre-operative planning and patient counseling prior to anterior cruciate ligament reconstruction.