Height, Weight, and Age Predict Quadriceps Tendon Length and Thickness in Skeletally Immature Patients

Abstract

Background: Quadriceps tendon autografts have been used with success in adults and are becoming a popular graft option in pediatric patients because of size, decreased donor site morbidity, ease of harvest, and favorable biomechanical characteristics. However, little is known about the length and thickness of the quadriceps tendon in pediatric patients. Purpose: This study aimed to determine whether quadriceps tendon length and thickness follow a predictable pattern of development based on height, weight, age, and body mass index in skeletally immature patients. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The height, weight, age, and sex of 151 children between 4 and 16 years old were recorded. Ultrasound measurements of the length and thickness of bilateral quadriceps tendons were performed by a single technician and recorded for statistical analysis. Results: The average quadriceps tendon length and thickness were 6.87 ± 1.49 cm and 0.37 ± 0.12 cm, respectively. Tendon length averaged 3.89 cm at age 4 years and 7.98 cm at 16 years, whereas thickness averaged 0.24 cm at 4 years and 0.40 cm at 16 years of age. There was no significant difference in tendon length or thickness between males and females ( P = .97). Tendon length and thickness increased significantly with age, weight, and height ( P < .01 for all). Conclusion: The quadriceps tendon is of sufficient length and thickness to be used as an autograft for pediatric patients. The size of the graft is predictable using the age, height, and weight of the patient. Graft length and thickness can be easily confirmed using ultrasound.