Normative spleen size in tall healthy athletes: Implications for safe return to contact sports after infectious mononucleosis

Objective: To establish normative parameters of the spleen by ultrasonography in tall athletes. Design: Prospective cohort observational study. SETTING:: University of Buffalo, Erie County Community College, University of Texas at Tyler, and Austin College. PARTICIPANTS:: Sixty-six athletes enrolled and finished the study. Height requirements were at least 6 feet 2 inches for men and at least 5 feet 7 inches in women. INTERVENTIONS:: Measurement of spleen size in tall athletes. Main outcome measures: Ultrasound measurements of spleen size in tall athletes were compared with "normal-sized" controls from the literature. Mean, SD, and variance determined the sample distribution, and a one sample t test compared measurements in tall athletes with historical measurements in the average height population. Statistical significance was defined as P < 0.05. Results: Mean height was 192.26 cm (SD, ±6.52) for men and 176.54 cm (SD, ±5.19) for women. Mean splenic measurements for all subjects were 12.19 cm (SD, ±1.45) for spleen length, 8.88 cm (SD, ±0.96) for spleen width, and 5.55 cm (SD, ±0.76) for spleen thickness. The study mean for spleen length was 12.192 cm (95% confidence interval, 11.835-12.549) and population mean was 8.94 cm (2 tailed t test, P < 0.01). In this population of tall athletes, normal spleen size was significantly larger than the normal spleen size of an average individual. Conclusions: In the clinical arena, it can be difficult to know when the tall athletes with splenomegaly from infectious mononucleosis can safely return to contact sports. Previously, there has not been a sufficient "norm" for this population, but this study helps to establish baseline values.